drivers/block/rbd.c

   1
   2 /*
   3    rbd.c -- Export ceph rados objects as a Linux block device
   4
   5
   6    based on drivers/block/osdblk.c:
   7
   8    Copyright 2009 Red Hat, Inc.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; see the file COPYING.  If not, write to
  21    the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  22
  23
  24
  25    For usage instructions, please refer to:
  26
  27                  Documentation/ABI/testing/sysfs-bus-rbd
  28
  29  */
  30
  31 #include <linux/ceph/libceph.h>
  32 #include <linux/ceph/osd_client.h>
  33 #include <linux/ceph/mon_client.h>
  34 #include <linux/ceph/cls_lock_client.h>
  35 #include <linux/ceph/decode.h>
  36 #include <linux/parser.h>
  37 #include <linux/bsearch.h>
  38
  39 #include <linux/kernel.h>
  40 #include <linux/device.h>
  41 #include <linux/module.h>
  42 #include <linux/blk-mq.h>
  43 #include <linux/fs.h>
  44 #include <linux/blkdev.h>
  45 #include <linux/slab.h>
  46 #include <linux/idr.h>
  47 #include <linux/workqueue.h>
  48
  49 #include "rbd_types.h"
  50
  51 #define RBD_DEBUG       /* Activate rbd_assert() calls */
  52
  53 /*
  54  * The basic unit of block I/O is a sector.  It is interpreted in a
  55  * number of contexts in Linux (blk, bio, genhd), but the default is
  56  * universally 512 bytes.  These symbols are just slightly more
  57  * meaningful than the bare numbers they represent.
  58  */
  59 #define SECTOR_SHIFT    9
  60 #define SECTOR_SIZE     (1ULL << SECTOR_SHIFT)
  61
  62 /*
  63  * Increment the given counter and return its updated value.
  64  * If the counter is already 0 it will not be incremented.
  65  * If the counter is already at its maximum value returns
  66  * -EINVAL without updating it.
  67  */
  68 static int atomic_inc_return_safe(atomic_t *v)
  69 {
  70         unsigned int counter;
  71
  72         counter = (unsigned int)__atomic_add_unless(v, 1, 0);
  73         if (counter <= (unsigned int)INT_MAX)
  74                 return (int)counter;
  75
  76         atomic_dec(v);
  77
  78         return -EINVAL;
  79 }
  80
  81 /* Decrement the counter.  Return the resulting value, or -EINVAL */
  82 static int atomic_dec_return_safe(atomic_t *v)
  83 {
  84         int counter;
  85
  86         counter = atomic_dec_return(v);
  87         if (counter >= 0)
  88                 return counter;
  89
  90         atomic_inc(v);
  91
  92         return -EINVAL;
  93 }
  94
  95 #define RBD_DRV_NAME "rbd"
  96
  97 #define RBD_MINORS_PER_MAJOR            256
  98 #define RBD_SINGLE_MAJOR_PART_SHIFT     4
  99
 100 #define RBD_MAX_PARENT_CHAIN_LEN        16
 101
 102 #define RBD_SNAP_DEV_NAME_PREFIX        "snap_"
 103 #define RBD_MAX_SNAP_NAME_LEN   \
 104                         (NAME_MAX - (sizeof (RBD_SNAP_DEV_NAME_PREFIX) - 1))
 105
 106 #define RBD_MAX_SNAP_COUNT      510     /* allows max snapc to fit in 4KB */
 107
 108 #define RBD_SNAP_HEAD_NAME      "-"
 109
 110 #define BAD_SNAP_INDEX  U32_MAX         /* invalid index into snap array */
 111
 112 /* This allows a single page to hold an image name sent by OSD */
 113 #define RBD_IMAGE_NAME_LEN_MAX  (PAGE_SIZE - sizeof (__le32) - 1)
 114 #define RBD_IMAGE_ID_LEN_MAX    64
 115
 116 #define RBD_OBJ_PREFIX_LEN_MAX  64
 117
 118 #define RBD_NOTIFY_TIMEOUT      5       /* seconds */
 119 #define RBD_RETRY_DELAY         msecs_to_jiffies(1000)
 120
 121 /* Feature bits */
 122
 123 #define RBD_FEATURE_LAYERING    (1<<0)
 124 #define RBD_FEATURE_STRIPINGV2  (1<<1)
 125 #define RBD_FEATURE_EXCLUSIVE_LOCK (1<<2)
 126 #define RBD_FEATURES_ALL        (RBD_FEATURE_LAYERING |         \
 127                                  RBD_FEATURE_STRIPINGV2 |       \
 128                                  RBD_FEATURE_EXCLUSIVE_LOCK)
 129
 130 /* Features supported by this (client software) implementation. */
 131
 132 #define RBD_FEATURES_SUPPORTED  (RBD_FEATURES_ALL)
 133
 134 /*
 135  * An RBD device name will be "rbd#", where the "rbd" comes from
 136  * RBD_DRV_NAME above, and # is a unique integer identifier.
 137  */
 138 #define DEV_NAME_LEN            32
 139
 140 /*
 141  * block device image metadata (in-memory version)
 142  */
 143 struct rbd_image_header {
 144         /* These six fields never change for a given rbd image */
 145         char *object_prefix;
 146         __u8 obj_order;
 147         __u8 crypt_type;
 148         __u8 comp_type;
 149         u64 stripe_unit;
 150         u64 stripe_count;
 151         u64 features;           /* Might be changeable someday? */
 152
 153         /* The remaining fields need to be updated occasionally */
 154         u64 image_size;
 155         struct ceph_snap_context *snapc;
 156         char *snap_names;       /* format 1 only */
 157         u64 *snap_sizes;        /* format 1 only */
 158 };
 159
 160 /*
 161  * An rbd image specification.
 162  *
 163  * The tuple (pool_id, image_id, snap_id) is sufficient to uniquely
 164  * identify an image.  Each rbd_dev structure includes a pointer to
 165  * an rbd_spec structure that encapsulates this identity.
 166  *
 167  * Each of the id's in an rbd_spec has an associated name.  For a
 168  * user-mapped image, the names are supplied and the id's associated
 169  * with them are looked up.  For a layered image, a parent image is
 170  * defined by the tuple, and the names are looked up.
 171  *
 172  * An rbd_dev structure contains a parent_spec pointer which is
 173  * non-null if the image it represents is a child in a layered
 174  * image.  This pointer will refer to the rbd_spec structure used
 175  * by the parent rbd_dev for its own identity (i.e., the structure
 176  * is shared between the parent and child).
 177  *
 178  * Since these structures are populated once, during the discovery
 179  * phase of image construction, they are effectively immutable so
 180  * we make no effort to synchronize access to them.
 181  *
 182  * Note that code herein does not assume the image name is known (it
 183  * could be a null pointer).
 184  */
 185 struct rbd_spec {
 186         u64             pool_id;
 187         const char      *pool_name;
 188
 189         const char      *image_id;
 190         const char      *image_name;
 191
 192         u64             snap_id;
 193         const char      *snap_name;
 194
 195         struct kref     kref;
 196 };
 197
 198 /*
 199  * an instance of the client.  multiple devices may share an rbd client.
 200  */
 201 struct rbd_client {
 202         struct ceph_client      *client;
 203         struct kref             kref;
 204         struct list_head        node;
 205 };
 206
 207 struct rbd_img_request;
 208 typedef void (*rbd_img_callback_t)(struct rbd_img_request *);
 209
 210 #define BAD_WHICH       U32_MAX         /* Good which or bad which, which? */
 211
 212 struct rbd_obj_request;
 213 typedef void (*rbd_obj_callback_t)(struct rbd_obj_request *);
 214
 215 enum obj_request_type {
 216         OBJ_REQUEST_NODATA, OBJ_REQUEST_BIO, OBJ_REQUEST_PAGES
 217 };
 218
 219 enum obj_operation_type {
 220         OBJ_OP_WRITE,
 221         OBJ_OP_READ,
 222         OBJ_OP_DISCARD,
 223 };
 224
 225 enum obj_req_flags {
 226         OBJ_REQ_DONE,           /* completion flag: not done = 0, done = 1 */
 227         OBJ_REQ_IMG_DATA,       /* object usage: standalone = 0, image = 1 */
 228         OBJ_REQ_KNOWN,          /* EXISTS flag valid: no = 0, yes = 1 */
 229         OBJ_REQ_EXISTS,         /* target exists: no = 0, yes = 1 */
 230 };
 231
 232 struct rbd_obj_request {
 233         const char              *object_name;
 234         u64                     offset;         /* object start byte */
 235         u64                     length;         /* bytes from offset */
 236         unsigned long           flags;
 237
 238         /*
 239          * An object request associated with an image will have its
 240          * img_data flag set; a standalone object request will not.
 241          *
 242          * A standalone object request will have which == BAD_WHICH
 243          * and a null obj_request pointer.
 244          *
 245          * An object request initiated in support of a layered image
 246          * object (to check for its existence before a write) will
 247          * have which == BAD_WHICH and a non-null obj_request pointer.
 248          *
 249          * Finally, an object request for rbd image data will have
 250          * which != BAD_WHICH, and will have a non-null img_request
 251          * pointer.  The value of which will be in the range
 252          * 0..(img_request->obj_request_count-1).
 253          */
 254         union {
 255                 struct rbd_obj_request  *obj_request;   /* STAT op */
 256                 struct {
 257                         struct rbd_img_request  *img_request;
 258                         u64                     img_offset;
 259                         /* links for img_request->obj_requests list */
 260                         struct list_head        links;
 261                 };
 262         };
 263         u32                     which;          /* posn image request list */
 264
 265         enum obj_request_type   type;
 266         union {
 267                 struct bio      *bio_list;
 268                 struct {
 269                         struct page     **pages;
 270                         u32             page_count;
 271                 };
 272         };
 273         struct page             **copyup_pages;
 274         u32                     copyup_page_count;
 275
 276         struct ceph_osd_request *osd_req;
 277
 278         u64                     xferred;        /* bytes transferred */
 279         int                     result;
 280
 281         rbd_obj_callback_t      callback;
 282         struct completion       completion;
 283
 284         struct kref             kref;
 285 };
 286
 287 enum img_req_flags {
 288         IMG_REQ_WRITE,          /* I/O direction: read = 0, write = 1 */
 289         IMG_REQ_CHILD,          /* initiator: block = 0, child image = 1 */
 290         IMG_REQ_LAYERED,        /* ENOENT handling: normal = 0, layered = 1 */
 291         IMG_REQ_DISCARD,        /* discard: normal = 0, discard request = 1 */
 292 };
 293
 294 struct rbd_img_request {
 295         struct rbd_device       *rbd_dev;
 296         u64                     offset; /* starting image byte offset */
 297         u64                     length; /* byte count from offset */
 298         unsigned long           flags;
 299         union {
 300                 u64                     snap_id;        /* for reads */
 301                 struct ceph_snap_context *snapc;        /* for writes */
 302         };
 303         union {
 304                 struct request          *rq;            /* block request */
 305                 struct rbd_obj_request  *obj_request;   /* obj req initiator */
 306         };
 307         struct page             **copyup_pages;
 308         u32                     copyup_page_count;
 309         spinlock_t              completion_lock;/* protects next_completion */
 310         u32                     next_completion;
 311         rbd_img_callback_t      callback;
 312         u64                     xferred;/* aggregate bytes transferred */
 313         int                     result; /* first nonzero obj_request result */
 314
 315         u32                     obj_request_count;
 316         struct list_head        obj_requests;   /* rbd_obj_request structs */
 317
 318         struct kref             kref;
 319 };
 320
 321 #define for_each_obj_request(ireq, oreq) \
 322         list_for_each_entry(oreq, &(ireq)->obj_requests, links)
 323 #define for_each_obj_request_from(ireq, oreq) \
 324         list_for_each_entry_from(oreq, &(ireq)->obj_requests, links)
 325 #define for_each_obj_request_safe(ireq, oreq, n) \
 326         list_for_each_entry_safe_reverse(oreq, n, &(ireq)->obj_requests, links)
 327
 328 enum rbd_watch_state {
 329         RBD_WATCH_STATE_UNREGISTERED,
 330         RBD_WATCH_STATE_REGISTERED,
 331         RBD_WATCH_STATE_ERROR,
 332 };
 333
 334 enum rbd_lock_state {
 335         RBD_LOCK_STATE_UNLOCKED,
 336         RBD_LOCK_STATE_LOCKED,
 337         RBD_LOCK_STATE_RELEASING,
 338 };
 339
 340 /* WatchNotify::ClientId */
 341 struct rbd_client_id {
 342         u64 gid;
 343         u64 handle;
 344 };
 345
 346 struct rbd_mapping {
 347         u64                     size;
 348         u64                     features;
 349         bool                    read_only;
 350 };
 351
 352 /*
 353  * a single device
 354  */
 355 struct rbd_device {
 356         int                     dev_id;         /* blkdev unique id */
 357
 358         int                     major;          /* blkdev assigned major */
 359         int                     minor;
 360         struct gendisk          *disk;          /* blkdev's gendisk and rq */
 361
 362         u32                     image_format;   /* Either 1 or 2 */
 363         struct rbd_client       *rbd_client;
 364
 365         char                    name[DEV_NAME_LEN]; /* blkdev name, e.g. rbd3 */
 366
 367         spinlock_t              lock;           /* queue, flags, open_count */
 368
 369         struct rbd_image_header header;
 370         unsigned long           flags;          /* possibly lock protected */
 371         struct rbd_spec         *spec;
 372         struct rbd_options      *opts;
 373         char                    *config_info;   /* add{,_single_major} string */
 374
 375         struct ceph_object_id   header_oid;
 376         struct ceph_object_locator header_oloc;
 377
 378         struct ceph_file_layout layout;         /* used for all rbd requests */
 379
 380         struct mutex            watch_mutex;
 381         enum rbd_watch_state    watch_state;
 382         struct ceph_osd_linger_request *watch_handle;
 383         u64                     watch_cookie;
 384         struct delayed_work     watch_dwork;
 385
 386         struct rw_semaphore     lock_rwsem;
 387         enum rbd_lock_state     lock_state;
 388         struct rbd_client_id    owner_cid;
 389         struct work_struct      acquired_lock_work;
 390         struct work_struct      released_lock_work;
 391         struct delayed_work     lock_dwork;
 392         struct work_struct      unlock_work;
 393         wait_queue_head_t       lock_waitq;
 394
 395         struct workqueue_struct *task_wq;
 396
 397         struct rbd_spec         *parent_spec;
 398         u64                     parent_overlap;
 399         atomic_t                parent_ref;
 400         struct rbd_device       *parent;
 401
 402         /* Block layer tags. */
 403         struct blk_mq_tag_set   tag_set;
 404
 405         /* protects updating the header */
 406         struct rw_semaphore     header_rwsem;
 407
 408         struct rbd_mapping      mapping;
 409
 410         struct list_head        node;
 411
 412         /* sysfs related */
 413         struct device           dev;
 414         unsigned long           open_count;     /* protected by lock */
 415 };
 416
 417 /*
 418  * Flag bits for rbd_dev->flags.  If atomicity is required,
 419  * rbd_dev->lock is used to protect access.
 420  *
 421  * Currently, only the "removing" flag (which is coupled with the
 422  * "open_count" field) requires atomic access.
 423  */
 424 enum rbd_dev_flags {
 425         RBD_DEV_FLAG_EXISTS,    /* mapped snapshot has not been deleted */
 426         RBD_DEV_FLAG_REMOVING,  /* this mapping is being removed */
 427 };
 428
 429 static DEFINE_MUTEX(client_mutex);      /* Serialize client creation */
 430
 431 static LIST_HEAD(rbd_dev_list);    /* devices */
 432 static DEFINE_SPINLOCK(rbd_dev_list_lock);
 433
 434 static LIST_HEAD(rbd_client_list);              /* clients */
 435 static DEFINE_SPINLOCK(rbd_client_list_lock);
 436
 437 /* Slab caches for frequently-allocated structures */
 438
 439 static struct kmem_cache        *rbd_img_request_cache;
 440 static struct kmem_cache        *rbd_obj_request_cache;
 441 static struct kmem_cache        *rbd_segment_name_cache;
 442
 443 static int rbd_major;
 444 static DEFINE_IDA(rbd_dev_id_ida);
 445
 446 static struct workqueue_struct *rbd_wq;
 447
 448 /*
 449  * Default to false for now, as single-major requires >= 0.75 version of
 450  * userspace rbd utility.
 451  */
 452 static bool single_major = false;
 453 module_param(single_major, bool, S_IRUGO);
 454 MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: false)");
 455
 456 static int rbd_img_request_submit(struct rbd_img_request *img_request);
 457
 458 static ssize_t rbd_add(struct bus_type *bus, const char *buf,
 459                        size_t count);
 460 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
 461                           size_t count);
 462 static ssize_t rbd_add_single_major(struct bus_type *bus, const char *buf,
 463                                     size_t count);
 464 static ssize_t rbd_remove_single_major(struct bus_type *bus, const char *buf,
 465                                        size_t count);
 466 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth);
 467 static void rbd_spec_put(struct rbd_spec *spec);
 468
 469 static int rbd_dev_id_to_minor(int dev_id)
 470 {
 471         return dev_id << RBD_SINGLE_MAJOR_PART_SHIFT;
 472 }
 473
 474 static int minor_to_rbd_dev_id(int minor)
 475 {
 476         return minor >> RBD_SINGLE_MAJOR_PART_SHIFT;
 477 }
 478
 479 static bool rbd_is_lock_supported(struct rbd_device *rbd_dev)
 480 {
 481         return (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) &&
 482                rbd_dev->spec->snap_id == CEPH_NOSNAP &&
 483                !rbd_dev->mapping.read_only;
 484 }
 485
 486 static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
 487 {
 488         return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
 489                rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
 490 }
 491
 492 static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
 493 {
 494         bool is_lock_owner;
 495
 496         down_read(&rbd_dev->lock_rwsem);
 497         is_lock_owner = __rbd_is_lock_owner(rbd_dev);
 498         up_read(&rbd_dev->lock_rwsem);
 499         return is_lock_owner;
 500 }
 501
 502 static BUS_ATTR(add, S_IWUSR, NULL, rbd_add);
 503 static BUS_ATTR(remove, S_IWUSR, NULL, rbd_remove);
 504 static BUS_ATTR(add_single_major, S_IWUSR, NULL, rbd_add_single_major);
 505 static BUS_ATTR(remove_single_major, S_IWUSR, NULL, rbd_remove_single_major);
 506
 507 static struct attribute *rbd_bus_attrs[] = {
 508         &bus_attr_add.attr,
 509         &bus_attr_remove.attr,
 510         &bus_attr_add_single_major.attr,
 511         &bus_attr_remove_single_major.attr,
 512         NULL,
 513 };
 514
 515 static umode_t rbd_bus_is_visible(struct kobject *kobj,
 516                                   struct attribute *attr, int index)
 517 {
 518         if (!single_major &&
 519             (attr == &bus_attr_add_single_major.attr ||
 520              attr == &bus_attr_remove_single_major.attr))
 521                 return 0;
 522
 523         return attr->mode;
 524 }
 525
 526 static const struct attribute_group rbd_bus_group = {
 527         .attrs = rbd_bus_attrs,
 528         .is_visible = rbd_bus_is_visible,
 529 };
 530 __ATTRIBUTE_GROUPS(rbd_bus);
 531
 532 static struct bus_type rbd_bus_type = {
 533         .name           = "rbd",
 534         .bus_groups     = rbd_bus_groups,
 535 };
 536
 537 static void rbd_root_dev_release(struct device *dev)
 538 {
 539 }
 540
 541 static struct device rbd_root_dev = {
 542         .init_name =    "rbd",
 543         .release =      rbd_root_dev_release,
 544 };
 545
 546 static __printf(2, 3)
 547 void rbd_warn(struct rbd_device *rbd_dev, const char *fmt, ...)
 548 {
 549         struct va_format vaf;
 550         va_list args;
 551
 552         va_start(args, fmt);
 553         vaf.fmt = fmt;
 554         vaf.va = &args;
 555
 556         if (!rbd_dev)
 557                 printk(KERN_WARNING "%s: %pV\n", RBD_DRV_NAME, &vaf);
 558         else if (rbd_dev->disk)
 559                 printk(KERN_WARNING "%s: %s: %pV\n",
 560                         RBD_DRV_NAME, rbd_dev->disk->disk_name, &vaf);
 561         else if (rbd_dev->spec && rbd_dev->spec->image_name)
 562                 printk(KERN_WARNING "%s: image %s: %pV\n",
 563                         RBD_DRV_NAME, rbd_dev->spec->image_name, &vaf);
 564         else if (rbd_dev->spec && rbd_dev->spec->image_id)
 565                 printk(KERN_WARNING "%s: id %s: %pV\n",
 566                         RBD_DRV_NAME, rbd_dev->spec->image_id, &vaf);
 567         else    /* punt */
 568                 printk(KERN_WARNING "%s: rbd_dev %p: %pV\n",
 569                         RBD_DRV_NAME, rbd_dev, &vaf);
 570         va_end(args);
 571 }
 572
 573 #ifdef RBD_DEBUG
 574 #define rbd_assert(expr)                                                \
 575                 if (unlikely(!(expr))) {                                \
 576                         printk(KERN_ERR "\nAssertion failure in %s() "  \
 577                                                 "at line %d:\n\n"       \
 578                                         "\trbd_assert(%s);\n\n",        \
 579                                         __func__, __LINE__, #expr);     \
 580                         BUG();                                          \
 581                 }
 582 #else /* !RBD_DEBUG */
 583 #  define rbd_assert(expr)      ((void) 0)
 584 #endif /* !RBD_DEBUG */
 585
 586 static void rbd_osd_copyup_callback(struct rbd_obj_request *obj_request);
 587 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request);
 588 static void rbd_img_parent_read(struct rbd_obj_request *obj_request);
 589 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev);
 590
 591 static int rbd_dev_refresh(struct rbd_device *rbd_dev);
 592 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev);
 593 static int rbd_dev_header_info(struct rbd_device *rbd_dev);
 594 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev);
 595 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
 596                                         u64 snap_id);
 597 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
 598                                 u8 *order, u64 *snap_size);
 599 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
 600                 u64 *snap_features);
 601
 602 static int rbd_open(struct block_device *bdev, fmode_t mode)
 603 {
 604         struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 605         bool removing = false;
 606
 607         if ((mode & FMODE_WRITE) && rbd_dev->mapping.read_only)
 608                 return -EROFS;
 609
 610         spin_lock_irq(&rbd_dev->lock);
 611         if (test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags))
 612                 removing = true;
 613         else
 614                 rbd_dev->open_count++;
 615         spin_unlock_irq(&rbd_dev->lock);
 616         if (removing)
 617                 return -ENOENT;
 618
 619         (void) get_device(&rbd_dev->dev);
 620
 621         return 0;
 622 }
 623
 624 static void rbd_release(struct gendisk *disk, fmode_t mode)
 625 {
 626         struct rbd_device *rbd_dev = disk->private_data;
 627         unsigned long open_count_before;
 628
 629         spin_lock_irq(&rbd_dev->lock);
 630         open_count_before = rbd_dev->open_count--;
 631         spin_unlock_irq(&rbd_dev->lock);
 632         rbd_assert(open_count_before > 0);
 633
 634         put_device(&rbd_dev->dev);
 635 }
 636
 637 static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
 638 {
 639         int ret = 0;
 640         int val;
 641         bool ro;
 642         bool ro_changed = false;
 643
 644         /* get_user() may sleep, so call it before taking rbd_dev->lock */
 645         if (get_user(val, (int __user *)(arg)))
 646                 return -EFAULT;
 647
 648         ro = val ? true : false;
 649         /* Snapshot doesn't allow to write*/
 650         if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
 651                 return -EROFS;
 652
 653         spin_lock_irq(&rbd_dev->lock);
 654         /* prevent others open this device */
 655         if (rbd_dev->open_count > 1) {
 656                 ret = -EBUSY;
 657                 goto out;
 658         }
 659
 660         if (rbd_dev->mapping.read_only != ro) {
 661                 rbd_dev->mapping.read_only = ro;
 662                 ro_changed = true;
 663         }
 664
 665 out:
 666         spin_unlock_irq(&rbd_dev->lock);
 667         /* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
 668         if (ret == 0 && ro_changed)
 669                 set_disk_ro(rbd_dev->disk, ro ? 1 : 0);
 670
 671         return ret;
 672 }
 673
 674 static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
 675                         unsigned int cmd, unsigned long arg)
 676 {
 677         struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 678         int ret = 0;
 679
 680         switch (cmd) {
 681         case BLKROSET:
 682                 ret = rbd_ioctl_set_ro(rbd_dev, arg);
 683                 break;
 684         default:
 685                 ret = -ENOTTY;
 686         }
 687
 688         return ret;
 689 }
 690
 691 #ifdef CONFIG_COMPAT
 692 static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
 693                                 unsigned int cmd, unsigned long arg)
 694 {
 695         return rbd_ioctl(bdev, mode, cmd, arg);
 696 }
 697 #endif /* CONFIG_COMPAT */
 698
 699 static const struct block_device_operations rbd_bd_ops = {
 700         .owner                  = THIS_MODULE,
 701         .open                   = rbd_open,
 702         .release                = rbd_release,
 703         .ioctl                  = rbd_ioctl,
 704 #ifdef CONFIG_COMPAT
 705         .compat_ioctl           = rbd_compat_ioctl,
 706 #endif
 707 };
 708
 709 /*
 710  * Initialize an rbd client instance.  Success or not, this function
 711  * consumes ceph_opts.  Caller holds client_mutex.
 712  */
 713 static struct rbd_client *rbd_client_create(struct ceph_options *ceph_opts)
 714 {
 715         struct rbd_client *rbdc;
 716         int ret = -ENOMEM;
 717
 718         dout("%s:\n", __func__);
 719         rbdc = kmalloc(sizeof(struct rbd_client), GFP_KERNEL);
 720         if (!rbdc)
 721                 goto out_opt;
 722
 723         kref_init(&rbdc->kref);
 724         INIT_LIST_HEAD(&rbdc->node);
 725
 726         rbdc->client = ceph_create_client(ceph_opts, rbdc, 0, 0);
 727         if (IS_ERR(rbdc->client))
 728                 goto out_rbdc;
 729         ceph_opts = NULL; /* Now rbdc->client is responsible for ceph_opts */
 730
 731         ret = ceph_open_session(rbdc->client);
 732         if (ret < 0)
 733                 goto out_client;
 734
 735         spin_lock(&rbd_client_list_lock);
 736         list_add_tail(&rbdc->node, &rbd_client_list);
 737         spin_unlock(&rbd_client_list_lock);
 738
 739         dout("%s: rbdc %p\n", __func__, rbdc);
 740
 741         return rbdc;
 742 out_client:
 743         ceph_destroy_client(rbdc->client);
 744 out_rbdc:
 745         kfree(rbdc);
 746 out_opt:
 747         if (ceph_opts)
 748                 ceph_destroy_options(ceph_opts);
 749         dout("%s: error %d\n", __func__, ret);
 750
 751         return ERR_PTR(ret);
 752 }
 753
 754 static struct rbd_client *__rbd_get_client(struct rbd_client *rbdc)
 755 {
 756         kref_get(&rbdc->kref);
 757
 758         return rbdc;
 759 }
 760
 761 /*
 762  * Find a ceph client with specific addr and configuration.  If
 763  * found, bump its reference count.
 764  */
 765 static struct rbd_client *rbd_client_find(struct ceph_options *ceph_opts)
 766 {
 767         struct rbd_client *client_node;
 768         bool found = false;
 769
 770         if (ceph_opts->flags & CEPH_OPT_NOSHARE)
 771                 return NULL;
 772
 773         spin_lock(&rbd_client_list_lock);
 774         list_for_each_entry(client_node, &rbd_client_list, node) {
 775                 if (!ceph_compare_options(ceph_opts, client_node->client)) {
 776                         __rbd_get_client(client_node);
 777
 778                         found = true;
 779                         break;
 780                 }
 781         }
 782         spin_unlock(&rbd_client_list_lock);
 783
 784         return found ? client_node : NULL;
 785 }
 786
 787 /*
 788  * (Per device) rbd map options
 789  */
 790 enum {
 791         Opt_queue_depth,
 792         Opt_last_int,
 793         /* int args above */
 794         Opt_last_string,
 795         /* string args above */
 796         Opt_read_only,
 797         Opt_read_write,
 798         Opt_lock_on_read,
 799         Opt_err
 800 };
 801
 802 static match_table_t rbd_opts_tokens = {
 803         {Opt_queue_depth, "queue_depth=%d"},
 804         /* int args above */
 805         /* string args above */
 806         {Opt_read_only, "read_only"},
 807         {Opt_read_only, "ro"},          /* Alternate spelling */
 808         {Opt_read_write, "read_write"},
 809         {Opt_read_write, "rw"},         /* Alternate spelling */
 810         {Opt_lock_on_read, "lock_on_read"},
 811         {Opt_err, NULL}
 812 };
 813
 814 struct rbd_options {
 815         int     queue_depth;
 816         bool    read_only;
 817         bool    lock_on_read;
 818 };
 819
 820 #define RBD_QUEUE_DEPTH_DEFAULT BLKDEV_MAX_RQ
 821 #define RBD_READ_ONLY_DEFAULT   false
 822 #define RBD_LOCK_ON_READ_DEFAULT false
 823
 824 static int parse_rbd_opts_token(char *c, void *private)
 825 {
 826         struct rbd_options *rbd_opts = private;
 827         substring_t argstr[MAX_OPT_ARGS];
 828         int token, intval, ret;
 829
 830         token = match_token(c, rbd_opts_tokens, argstr);
 831         if (token < Opt_last_int) {
 832                 ret = match_int(&argstr[0], &intval);
 833                 if (ret < 0) {
 834                         pr_err("bad mount option arg (not int) at '%s'\n", c);
 835                         return ret;
 836                 }
 837                 dout("got int token %d val %d\n", token, intval);
 838         } else if (token > Opt_last_int && token < Opt_last_string) {
 839                 dout("got string token %d val %s\n", token, argstr[0].from);
 840         } else {
 841                 dout("got token %d\n", token);
 842         }
 843
 844         switch (token) {
 845         case Opt_queue_depth:
 846                 if (intval < 1) {
 847                         pr_err("queue_depth out of range\n");
 848                         return -EINVAL;
 849                 }
 850                 rbd_opts->queue_depth = intval;
 851                 break;
 852         case Opt_read_only:
 853                 rbd_opts->read_only = true;
 854                 break;
 855         case Opt_read_write:
 856                 rbd_opts->read_only = false;
 857                 break;
 858         case Opt_lock_on_read:
 859                 rbd_opts->lock_on_read = true;
 860                 break;
 861         default:
 862                 /* libceph prints "bad option" msg */
 863                 return -EINVAL;
 864         }
 865
 866         return 0;
 867 }
 868
 869 static char* obj_op_name(enum obj_operation_type op_type)
 870 {
 871         switch (op_type) {
 872         case OBJ_OP_READ:
 873                 return "read";
 874         case OBJ_OP_WRITE:
 875                 return "write";
 876         case OBJ_OP_DISCARD:
 877                 return "discard";
 878         default:
 879                 return "???";
 880         }
 881 }
 882
 883 /*
 884  * Get a ceph client with specific addr and configuration, if one does
 885  * not exist create it.  Either way, ceph_opts is consumed by this
 886  * function.
 887  */
 888 static struct rbd_client *rbd_get_client(struct ceph_options *ceph_opts)
 889 {
 890         struct rbd_client *rbdc;
 891
 892         mutex_lock_nested(&client_mutex, SINGLE_DEPTH_NESTING);
 893         rbdc = rbd_client_find(ceph_opts);
 894         if (rbdc)       /* using an existing client */
 895                 ceph_destroy_options(ceph_opts);
 896         else
 897                 rbdc = rbd_client_create(ceph_opts);
 898         mutex_unlock(&client_mutex);
 899
 900         return rbdc;
 901 }
 902
 903 /*
 904  * Destroy ceph client
 905  *
 906  * Caller must hold rbd_client_list_lock.
 907  */
 908 static void rbd_client_release(struct kref *kref)
 909 {
 910         struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref);
 911
 912         dout("%s: rbdc %p\n", __func__, rbdc);
 913         spin_lock(&rbd_client_list_lock);
 914         list_del(&rbdc->node);
 915         spin_unlock(&rbd_client_list_lock);
 916
 917         ceph_destroy_client(rbdc->client);
 918         kfree(rbdc);
 919 }
 920
 921 /*
 922  * Drop reference to ceph client node. If it's not referenced anymore, release
 923  * it.
 924  */
 925 static void rbd_put_client(struct rbd_client *rbdc)
 926 {
 927         if (rbdc)
 928                 kref_put(&rbdc->kref, rbd_client_release);
 929 }
 930
 931 static bool rbd_image_format_valid(u32 image_format)
 932 {
 933         return image_format == 1 || image_format == 2;
 934 }
 935
 936 static bool rbd_dev_ondisk_valid(struct rbd_image_header_ondisk *ondisk)
 937 {
 938         size_t size;
 939         u32 snap_count;
 940
 941         /* The header has to start with the magic rbd header text */
 942         if (memcmp(&ondisk->text, RBD_HEADER_TEXT, sizeof (RBD_HEADER_TEXT)))
 943                 return false;
 944
 945         /* The bio layer requires at least sector-sized I/O */
 946
 947         if (ondisk->options.order < SECTOR_SHIFT)
 948                 return false;
 949
 950         /* If we use u64 in a few spots we may be able to loosen this */
 951
 952         if (ondisk->options.order > 8 * sizeof (int) - 1)
 953                 return false;
 954
 955         /*
 956          * The size of a snapshot header has to fit in a size_t, and
 957          * that limits the number of snapshots.
 958          */
 959         snap_count = le32_to_cpu(ondisk->snap_count);
 960         size = SIZE_MAX - sizeof (struct ceph_snap_context);
 961         if (snap_count > size / sizeof (__le64))
 962                 return false;
 963
 964         /*
 965          * Not only that, but the size of the entire the snapshot
 966          * header must also be representable in a size_t.
 967          */
 968         size -= snap_count * sizeof (__le64);
 969         if ((u64) size < le64_to_cpu(ondisk->snap_names_len))
 970                 return false;
 971
 972         return true;
 973 }
 974
 975 /*
 976  * Fill an rbd image header with information from the given format 1
 977  * on-disk header.
 978  */
 979 static int rbd_header_from_disk(struct rbd_device *rbd_dev,
 980                                  struct rbd_image_header_ondisk *ondisk)
 981 {
 982         struct rbd_image_header *header = &rbd_dev->header;
 983         bool first_time = header->object_prefix == NULL;
 984         struct ceph_snap_context *snapc;
 985         char *object_prefix = NULL;
 986         char *snap_names = NULL;
 987         u64 *snap_sizes = NULL;
 988         u32 snap_count;
 989         size_t size;
 990         int ret = -ENOMEM;
 991         u32 i;
 992
 993         /* Allocate this now to avoid having to handle failure below */
 994
 995         if (first_time) {
 996                 size_t len;
 997
 998                 len = strnlen(ondisk->object_prefix,
 999                                 sizeof (ondisk->object_prefix));
1000                 object_prefix = kmalloc(len + 1, GFP_KERNEL);
1001                 if (!object_prefix)
1002                         return -ENOMEM;
1003                 memcpy(object_prefix, ondisk->object_prefix, len);
1004                 object_prefix[len] = '\0';
1005         }
1006
1007         /* Allocate the snapshot context and fill it in */
1008
1009         snap_count = le32_to_cpu(ondisk->snap_count);
1010         snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
1011         if (!snapc)
1012                 goto out_err;
1013         snapc->seq = le64_to_cpu(ondisk->snap_seq);
1014         if (snap_count) {
1015                 struct rbd_image_snap_ondisk *snaps;
1016                 u64 snap_names_len = le64_to_cpu(ondisk->snap_names_len);
1017
1018                 /* We'll keep a copy of the snapshot names... */
1019
1020                 if (snap_names_len > (u64)SIZE_MAX)
1021                         goto out_2big;
1022                 snap_names = kmalloc(snap_names_len, GFP_KERNEL);
1023                 if (!snap_names)
1024                         goto out_err;
1025
1026                 /* ...as well as the array of their sizes. */
1027
1028                 size = snap_count * sizeof (*header->snap_sizes);
1029                 snap_sizes = kmalloc(size, GFP_KERNEL);
1030                 if (!snap_sizes)
1031                         goto out_err;
1032
1033                 /*
1034                  * Copy the names, and fill in each snapshot's id
1035                  * and size.
1036                  *
1037                  * Note that rbd_dev_v1_header_info() guarantees the
1038                  * ondisk buffer we're working with has
1039                  * snap_names_len bytes beyond the end of the
1040                  * snapshot id array, this memcpy() is safe.
1041                  */
1042                 memcpy(snap_names, &ondisk->snaps[snap_count], snap_names_len);
1043                 snaps = ondisk->snaps;
1044                 for (i = 0; i < snap_count; i++) {
1045                         snapc->snaps[i] = le64_to_cpu(snaps[i].id);
1046                         snap_sizes[i] = le64_to_cpu(snaps[i].image_size);
1047                 }
1048         }
1049
1050         /* We won't fail any more, fill in the header */
1051
1052         if (first_time) {
1053                 header->object_prefix = object_prefix;
1054                 header->obj_order = ondisk->options.order;
1055                 header->crypt_type = ondisk->options.crypt_type;
1056                 header->comp_type = ondisk->options.comp_type;
1057                 /* The rest aren't used for format 1 images */
1058                 header->stripe_unit = 0;
1059                 header->stripe_count = 0;
1060                 header->features = 0;
1061         } else {
1062                 ceph_put_snap_context(header->snapc);
1063                 kfree(header->snap_names);
1064                 kfree(header->snap_sizes);
1065         }
1066
1067         /* The remaining fields always get updated (when we refresh) */
1068
1069         header->image_size = le64_to_cpu(ondisk->image_size);
1070         header->snapc = snapc;
1071         header->snap_names = snap_names;
1072         header->snap_sizes = snap_sizes;
1073
1074         return 0;
1075 out_2big:
1076         ret = -EIO;
1077 out_err:
1078         kfree(snap_sizes);
1079         kfree(snap_names);
1080         ceph_put_snap_context(snapc);
1081         kfree(object_prefix);
1082
1083         return ret;
1084 }
1085
1086 static const char *_rbd_dev_v1_snap_name(struct rbd_device *rbd_dev, u32 which)
1087 {
1088         const char *snap_name;
1089
1090         rbd_assert(which < rbd_dev->header.snapc->num_snaps);
1091
1092         /* Skip over names until we find the one we are looking for */
1093
1094         snap_name = rbd_dev->header.snap_names;
1095         while (which--)
1096                 snap_name += strlen(snap_name) + 1;
1097
1098         return kstrdup(snap_name, GFP_KERNEL);
1099 }
1100
1101 /*
1102  * Snapshot id comparison function for use with qsort()/bsearch().
1103  * Note that result is for snapshots in *descending* order.
1104  */
1105 static int snapid_compare_reverse(const void *s1, const void *s2)
1106 {
1107         u64 snap_id1 = *(u64 *)s1;
1108         u64 snap_id2 = *(u64 *)s2;
1109
1110         if (snap_id1 < snap_id2)
1111                 return 1;
1112         return snap_id1 == snap_id2 ? 0 : -1;
1113 }
1114
1115 /*
1116  * Search a snapshot context to see if the given snapshot id is
1117  * present.
1118  *
1119  * Returns the position of the snapshot id in the array if it's found,
1120  * or BAD_SNAP_INDEX otherwise.
1121  *
1122  * Note: The snapshot array is in kept sorted (by the osd) in
1123  * reverse order, highest snapshot id first.
1124  */
1125 static u32 rbd_dev_snap_index(struct rbd_device *rbd_dev, u64 snap_id)
1126 {
1127         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
1128         u64 *found;
1129
1130         found = bsearch(&snap_id, &snapc->snaps, snapc->num_snaps,
1131                                 sizeof (snap_id), snapid_compare_reverse);
1132
1133         return found ? (u32)(found - &snapc->snaps[0]) : BAD_SNAP_INDEX;
1134 }
1135
1136 static const char *rbd_dev_v1_snap_name(struct rbd_device *rbd_dev,
1137                                         u64 snap_id)
1138 {
1139         u32 which;
1140         const char *snap_name;
1141
1142         which = rbd_dev_snap_index(rbd_dev, snap_id);
1143         if (which == BAD_SNAP_INDEX)
1144                 return ERR_PTR(-ENOENT);
1145
1146         snap_name = _rbd_dev_v1_snap_name(rbd_dev, which);
1147         return snap_name ? snap_name : ERR_PTR(-ENOMEM);
1148 }
1149
1150 static const char *rbd_snap_name(struct rbd_device *rbd_dev, u64 snap_id)
1151 {
1152         if (snap_id == CEPH_NOSNAP)
1153                 return RBD_SNAP_HEAD_NAME;
1154
1155         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1156         if (rbd_dev->image_format == 1)
1157                 return rbd_dev_v1_snap_name(rbd_dev, snap_id);
1158
1159         return rbd_dev_v2_snap_name(rbd_dev, snap_id);
1160 }
1161
1162 static int rbd_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
1163                                 u64 *snap_size)
1164 {
1165         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1166         if (snap_id == CEPH_NOSNAP) {
1167                 *snap_size = rbd_dev->header.image_size;
1168         } else if (rbd_dev->image_format == 1) {
1169                 u32 which;
1170
1171                 which = rbd_dev_snap_index(rbd_dev, snap_id);
1172                 if (which == BAD_SNAP_INDEX)
1173                         return -ENOENT;
1174
1175                 *snap_size = rbd_dev->header.snap_sizes[which];
1176         } else {
1177                 u64 size = 0;
1178                 int ret;
1179
1180                 ret = _rbd_dev_v2_snap_size(rbd_dev, snap_id, NULL, &size);
1181                 if (ret)
1182                         return ret;
1183
1184                 *snap_size = size;
1185         }
1186         return 0;
1187 }
1188
1189 static int rbd_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
1190                         u64 *snap_features)
1191 {
1192         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
1193         if (snap_id == CEPH_NOSNAP) {
1194                 *snap_features = rbd_dev->header.features;
1195         } else if (rbd_dev->image_format == 1) {
1196                 *snap_features = 0;     /* No features for format 1 */
1197         } else {
1198                 u64 features = 0;
1199                 int ret;
1200
1201                 ret = _rbd_dev_v2_snap_features(rbd_dev, snap_id, &features);
1202                 if (ret)
1203                         return ret;
1204
1205                 *snap_features = features;
1206         }
1207         return 0;
1208 }
1209
1210 static int rbd_dev_mapping_set(struct rbd_device *rbd_dev)
1211 {
1212         u64 snap_id = rbd_dev->spec->snap_id;
1213         u64 size = 0;
1214         u64 features = 0;
1215         int ret;
1216
1217         ret = rbd_snap_size(rbd_dev, snap_id, &size);
1218         if (ret)
1219                 return ret;
1220         ret = rbd_snap_features(rbd_dev, snap_id, &features);
1221         if (ret)
1222                 return ret;
1223
1224         rbd_dev->mapping.size = size;
1225         rbd_dev->mapping.features = features;
1226
1227         return 0;
1228 }
1229
1230 static void rbd_dev_mapping_clear(struct rbd_device *rbd_dev)
1231 {
1232         rbd_dev->mapping.size = 0;
1233         rbd_dev->mapping.features = 0;
1234 }
1235
1236 static void rbd_segment_name_free(const char *name)
1237 {
1238         /* The explicit cast here is needed to drop the const qualifier */
1239
1240         kmem_cache_free(rbd_segment_name_cache, (void *)name);
1241 }
1242
1243 static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)
1244 {
1245         char *name;
1246         u64 segment;
1247         int ret;
1248         char *name_format;
1249
1250         name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO);
1251         if (!name)
1252                 return NULL;
1253         segment = offset >> rbd_dev->header.obj_order;
1254         name_format = "%s.%012llx";
1255         if (rbd_dev->image_format == 2)
1256                 name_format = "%s.%016llx";
1257         ret = snprintf(name, CEPH_MAX_OID_NAME_LEN + 1, name_format,
1258                         rbd_dev->header.object_prefix, segment);
1259         if (ret < 0 || ret > CEPH_MAX_OID_NAME_LEN) {
1260                 pr_err("error formatting segment name for #%llu (%d)\n",
1261                         segment, ret);
1262                 rbd_segment_name_free(name);
1263                 name = NULL;
1264         }
1265
1266         return name;
1267 }
1268
1269 static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset)
1270 {
1271         u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1272
1273         return offset & (segment_size - 1);
1274 }
1275
1276 static u64 rbd_segment_length(struct rbd_device *rbd_dev,
1277                                 u64 offset, u64 length)
1278 {
1279         u64 segment_size = (u64) 1 << rbd_dev->header.obj_order;
1280
1281         offset &= segment_size - 1;
1282
1283         rbd_assert(length <= U64_MAX - offset);
1284         if (offset + length > segment_size)
1285                 length = segment_size - offset;
1286
1287         return length;
1288 }
1289
1290 /*
1291  * returns the size of an object in the image
1292  */
1293 static u64 rbd_obj_bytes(struct rbd_image_header *header)
1294 {
1295         return 1 << header->obj_order;
1296 }
1297
1298 /*
1299  * bio helpers
1300  */
1301
1302 static void bio_chain_put(struct bio *chain)
1303 {
1304         struct bio *tmp;
1305
1306         while (chain) {
1307                 tmp = chain;
1308                 chain = chain->bi_next;
1309                 bio_put(tmp);
1310         }
1311 }
1312
1313 /*
1314  * zeros a bio chain, starting at specific offset
1315  */
1316 static void zero_bio_chain(struct bio *chain, int start_ofs)
1317 {
1318         struct bio_vec bv;
1319         struct bvec_iter iter;
1320         unsigned long flags;
1321         void *buf;
1322         int pos = 0;
1323
1324         while (chain) {
1325                 bio_for_each_segment(bv, chain, iter) {
1326                         if (pos + bv.bv_len > start_ofs) {
1327                                 int remainder = max(start_ofs - pos, 0);
1328                                 buf = bvec_kmap_irq(&bv, &flags);
1329                                 memset(buf + remainder, 0,
1330                                        bv.bv_len - remainder);
1331                                 flush_dcache_page(bv.bv_page);
1332                                 bvec_kunmap_irq(buf, &flags);
1333                         }
1334                         pos += bv.bv_len;
1335                 }
1336
1337                 chain = chain->bi_next;
1338         }
1339 }
1340
1341 /*
1342  * similar to zero_bio_chain(), zeros data defined by a page array,
1343  * starting at the given byte offset from the start of the array and
1344  * continuing up to the given end offset.  The pages array is
1345  * assumed to be big enough to hold all bytes up to the end.
1346  */
1347 static void zero_pages(struct page **pages, u64 offset, u64 end)
1348 {
1349         struct page **page = &pages[offset >> PAGE_SHIFT];
1350
1351         rbd_assert(end > offset);
1352         rbd_assert(end - offset <= (u64)SIZE_MAX);
1353         while (offset < end) {
1354                 size_t page_offset;
1355                 size_t length;
1356                 unsigned long flags;
1357                 void *kaddr;
1358
1359                 page_offset = offset & ~PAGE_MASK;
1360                 length = min_t(size_t, PAGE_SIZE - page_offset, end - offset);
1361                 local_irq_save(flags);
1362                 kaddr = kmap_atomic(*page);
1363                 memset(kaddr + page_offset, 0, length);
1364                 flush_dcache_page(*page);
1365                 kunmap_atomic(kaddr);
1366                 local_irq_restore(flags);
1367
1368                 offset += length;
1369                 page++;
1370         }
1371 }
1372
1373 /*
1374  * Clone a portion of a bio, starting at the given byte offset
1375  * and continuing for the number of bytes indicated.
1376  */
1377 static struct bio *bio_clone_range(struct bio *bio_src,
1378                                         unsigned int offset,
1379                                         unsigned int len,
1380                                         gfp_t gfpmask)
1381 {
1382         struct bio *bio;
1383
1384         bio = bio_clone(bio_src, gfpmask);
1385         if (!bio)
1386                 return NULL;    /* ENOMEM */
1387
1388         bio_advance(bio, offset);
1389         bio->bi_iter.bi_size = len;
1390
1391         return bio;
1392 }
1393
1394 /*
1395  * Clone a portion of a bio chain, starting at the given byte offset
1396  * into the first bio in the source chain and continuing for the
1397  * number of bytes indicated.  The result is another bio chain of
1398  * exactly the given length, or a null pointer on error.
1399  *
1400  * The bio_src and offset parameters are both in-out.  On entry they
1401  * refer to the first source bio and the offset into that bio where
1402  * the start of data to be cloned is located.
1403  *
1404  * On return, bio_src is updated to refer to the bio in the source
1405  * chain that contains first un-cloned byte, and *offset will
1406  * contain the offset of that byte within that bio.
1407  */
1408 static struct bio *bio_chain_clone_range(struct bio **bio_src,
1409                                         unsigned int *offset,
1410                                         unsigned int len,
1411                                         gfp_t gfpmask)
1412 {
1413         struct bio *bi = *bio_src;
1414         unsigned int off = *offset;
1415         struct bio *chain = NULL;
1416         struct bio **end;
1417
1418         /* Build up a chain of clone bios up to the limit */
1419
1420         if (!bi || off >= bi->bi_iter.bi_size || !len)
1421                 return NULL;            /* Nothing to clone */
1422
1423         end = &chain;
1424         while (len) {
1425                 unsigned int bi_size;
1426                 struct bio *bio;
1427
1428                 if (!bi) {
1429                         rbd_warn(NULL, "bio_chain exhausted with %u left", len);
1430                         goto out_err;   /* EINVAL; ran out of bio's */
1431                 }
1432                 bi_size = min_t(unsigned int, bi->bi_iter.bi_size - off, len);
1433                 bio = bio_clone_range(bi, off, bi_size, gfpmask);
1434                 if (!bio)
1435                         goto out_err;   /* ENOMEM */
1436
1437                 *end = bio;
1438                 end = &bio->bi_next;
1439
1440                 off += bi_size;
1441                 if (off == bi->bi_iter.bi_size) {
1442                         bi = bi->bi_next;
1443                         off = 0;
1444                 }
1445                 len -= bi_size;
1446         }
1447         *bio_src = bi;
1448         *offset = off;
1449
1450         return chain;
1451 out_err:
1452         bio_chain_put(chain);
1453
1454         return NULL;
1455 }
1456
1457 /*
1458  * The default/initial value for all object request flags is 0.  For
1459  * each flag, once its value is set to 1 it is never reset to 0
1460  * again.
1461  */
1462 static void obj_request_img_data_set(struct rbd_obj_request *obj_request)
1463 {
1464         if (test_and_set_bit(OBJ_REQ_IMG_DATA, &obj_request->flags)) {
1465                 struct rbd_device *rbd_dev;
1466
1467                 rbd_dev = obj_request->img_request->rbd_dev;
1468                 rbd_warn(rbd_dev, "obj_request %p already marked img_data",
1469                         obj_request);
1470         }
1471 }
1472
1473 static bool obj_request_img_data_test(struct rbd_obj_request *obj_request)
1474 {
1475         smp_mb();
1476         return test_bit(OBJ_REQ_IMG_DATA, &obj_request->flags) != 0;
1477 }
1478
1479 static void obj_request_done_set(struct rbd_obj_request *obj_request)
1480 {
1481         if (test_and_set_bit(OBJ_REQ_DONE, &obj_request->flags)) {
1482                 struct rbd_device *rbd_dev = NULL;
1483
1484                 if (obj_request_img_data_test(obj_request))
1485                         rbd_dev = obj_request->img_request->rbd_dev;
1486                 rbd_warn(rbd_dev, "obj_request %p already marked done",
1487                         obj_request);
1488         }
1489 }
1490
1491 static bool obj_request_done_test(struct rbd_obj_request *obj_request)
1492 {
1493         smp_mb();
1494         return test_bit(OBJ_REQ_DONE, &obj_request->flags) != 0;
1495 }
1496
1497 /*
1498  * This sets the KNOWN flag after (possibly) setting the EXISTS
1499  * flag.  The latter is set based on the "exists" value provided.
1500  *
1501  * Note that for our purposes once an object exists it never goes
1502  * away again.  It's possible that the response from two existence
1503  * checks are separated by the creation of the target object, and
1504  * the first ("doesn't exist") response arrives *after* the second
1505  * ("does exist").  In that case we ignore the second one.
1506  */
1507 static void obj_request_existence_set(struct rbd_obj_request *obj_request,
1508                                 bool exists)
1509 {
1510         if (exists)
1511                 set_bit(OBJ_REQ_EXISTS, &obj_request->flags);
1512         set_bit(OBJ_REQ_KNOWN, &obj_request->flags);
1513         smp_mb();
1514 }
1515
1516 static bool obj_request_known_test(struct rbd_obj_request *obj_request)
1517 {
1518         smp_mb();
1519         return test_bit(OBJ_REQ_KNOWN, &obj_request->flags) != 0;
1520 }
1521
1522 static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
1523 {
1524         smp_mb();
1525         return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
1526 }
1527
1528 static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
1529 {
1530         struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
1531
1532         return obj_request->img_offset <
1533             round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
1534 }
1535
1536 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
1537 {
1538         dout("%s: obj %p (was %d)\n", __func__, obj_request,
1539                 atomic_read(&obj_request->kref.refcount));
1540         kref_get(&obj_request->kref);
1541 }
1542
1543 static void rbd_obj_request_destroy(struct kref *kref);
1544 static void rbd_obj_request_put(struct rbd_obj_request *obj_request)
1545 {
1546         rbd_assert(obj_request != NULL);
1547         dout("%s: obj %p (was %d)\n", __func__, obj_request,
1548                 atomic_read(&obj_request->kref.refcount));
1549         kref_put(&obj_request->kref, rbd_obj_request_destroy);
1550 }
1551
1552 static void rbd_img_request_get(struct rbd_img_request *img_request)
1553 {
1554         dout("%s: img %p (was %d)\n", __func__, img_request,
1555              atomic_read(&img_request->kref.refcount));
1556         kref_get(&img_request->kref);
1557 }
1558
1559 static bool img_request_child_test(struct rbd_img_request *img_request);
1560 static void rbd_parent_request_destroy(struct kref *kref);
1561 static void rbd_img_request_destroy(struct kref *kref);
1562 static void rbd_img_request_put(struct rbd_img_request *img_request)
1563 {
1564         rbd_assert(img_request != NULL);
1565         dout("%s: img %p (was %d)\n", __func__, img_request,
1566                 atomic_read(&img_request->kref.refcount));
1567         if (img_request_child_test(img_request))
1568                 kref_put(&img_request->kref, rbd_parent_request_destroy);
1569         else
1570                 kref_put(&img_request->kref, rbd_img_request_destroy);
1571 }
1572
1573 static inline void rbd_img_obj_request_add(struct rbd_img_request *img_request,
1574                                         struct rbd_obj_request *obj_request)
1575 {
1576         rbd_assert(obj_request->img_request == NULL);
1577
1578         /* Image request now owns object's original reference */
1579         obj_request->img_request = img_request;
1580         obj_request->which = img_request->obj_request_count;
1581         rbd_assert(!obj_request_img_data_test(obj_request));
1582         obj_request_img_data_set(obj_request);
1583         rbd_assert(obj_request->which != BAD_WHICH);
1584         img_request->obj_request_count++;
1585         list_add_tail(&obj_request->links, &img_request->obj_requests);
1586         dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1587                 obj_request->which);
1588 }
1589
1590 static inline void rbd_img_obj_request_del(struct rbd_img_request *img_request,
1591                                         struct rbd_obj_request *obj_request)
1592 {
1593         rbd_assert(obj_request->which != BAD_WHICH);
1594
1595         dout("%s: img %p obj %p w=%u\n", __func__, img_request, obj_request,
1596                 obj_request->which);
1597         list_del(&obj_request->links);
1598         rbd_assert(img_request->obj_request_count > 0);
1599         img_request->obj_request_count--;
1600         rbd_assert(obj_request->which == img_request->obj_request_count);
1601         obj_request->which = BAD_WHICH;
1602         rbd_assert(obj_request_img_data_test(obj_request));
1603         rbd_assert(obj_request->img_request == img_request);
1604         obj_request->img_request = NULL;
1605         obj_request->callback = NULL;
1606         rbd_obj_request_put(obj_request);
1607 }
1608
1609 static bool obj_request_type_valid(enum obj_request_type type)
1610 {
1611         switch (type) {
1612         case OBJ_REQUEST_NODATA:
1613         case OBJ_REQUEST_BIO:
1614         case OBJ_REQUEST_PAGES:
1615                 return true;
1616         default:
1617                 return false;
1618         }
1619 }
1620
1621 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request);
1622
1623 static void rbd_obj_request_submit(struct rbd_obj_request *obj_request)
1624 {
1625         struct ceph_osd_request *osd_req = obj_request->osd_req;
1626
1627         dout("%s %p osd_req %p\n", __func__, obj_request, osd_req);
1628         if (obj_request_img_data_test(obj_request)) {
1629                 WARN_ON(obj_request->callback != rbd_img_obj_callback);
1630                 rbd_img_request_get(obj_request->img_request);
1631         }
1632         ceph_osdc_start_request(osd_req->r_osdc, osd_req, false);
1633 }
1634
1635 static void rbd_obj_request_end(struct rbd_obj_request *obj_request)
1636 {
1637         dout("%s %p\n", __func__, obj_request);
1638         ceph_osdc_cancel_request(obj_request->osd_req);
1639 }
1640
1641 /*
1642  * Wait for an object request to complete.  If interrupted, cancel the
1643  * underlying osd request.
1644  *
1645  * @timeout: in jiffies, 0 means "wait forever"
1646  */
1647 static int __rbd_obj_request_wait(struct rbd_obj_request *obj_request,
1648                                   unsigned long timeout)
1649 {
1650         long ret;
1651
1652         dout("%s %p\n", __func__, obj_request);
1653         ret = wait_for_completion_interruptible_timeout(
1654                                         &obj_request->completion,
1655                                         ceph_timeout_jiffies(timeout));
1656         if (ret <= 0) {
1657                 if (ret == 0)
1658                         ret = -ETIMEDOUT;
1659                 rbd_obj_request_end(obj_request);
1660         } else {
1661                 ret = 0;
1662         }
1663
1664         dout("%s %p ret %d\n", __func__, obj_request, (int)ret);
1665         return ret;
1666 }
1667
1668 static int rbd_obj_request_wait(struct rbd_obj_request *obj_request)
1669 {
1670         return __rbd_obj_request_wait(obj_request, 0);
1671 }
1672
1673 static void rbd_img_request_complete(struct rbd_img_request *img_request)
1674 {
1675
1676         dout("%s: img %p\n", __func__, img_request);
1677
1678         /*
1679          * If no error occurred, compute the aggregate transfer
1680          * count for the image request.  We could instead use
1681          * atomic64_cmpxchg() to update it as each object request
1682          * completes; not clear which way is better off hand.
1683          */
1684         if (!img_request->result) {
1685                 struct rbd_obj_request *obj_request;
1686                 u64 xferred = 0;
1687
1688                 for_each_obj_request(img_request, obj_request)
1689                         xferred += obj_request->xferred;
1690                 img_request->xferred = xferred;
1691         }
1692
1693         if (img_request->callback)
1694                 img_request->callback(img_request);
1695         else
1696                 rbd_img_request_put(img_request);
1697 }
1698
1699 /*
1700  * The default/initial value for all image request flags is 0.  Each
1701  * is conditionally set to 1 at image request initialization time
1702  * and currently never change thereafter.
1703  */
1704 static void img_request_write_set(struct rbd_img_request *img_request)
1705 {
1706         set_bit(IMG_REQ_WRITE, &img_request->flags);
1707         smp_mb();
1708 }
1709
1710 static bool img_request_write_test(struct rbd_img_request *img_request)
1711 {
1712         smp_mb();
1713         return test_bit(IMG_REQ_WRITE, &img_request->flags) != 0;
1714 }
1715
1716 /*
1717  * Set the discard flag when the img_request is an discard request
1718  */
1719 static void img_request_discard_set(struct rbd_img_request *img_request)
1720 {
1721         set_bit(IMG_REQ_DISCARD, &img_request->flags);
1722         smp_mb();
1723 }
1724
1725 static bool img_request_discard_test(struct rbd_img_request *img_request)
1726 {
1727         smp_mb();
1728         return test_bit(IMG_REQ_DISCARD, &img_request->flags) != 0;
1729 }
1730
1731 static void img_request_child_set(struct rbd_img_request *img_request)
1732 {
1733         set_bit(IMG_REQ_CHILD, &img_request->flags);
1734         smp_mb();
1735 }
1736
1737 static void img_request_child_clear(struct rbd_img_request *img_request)
1738 {
1739         clear_bit(IMG_REQ_CHILD, &img_request->flags);
1740         smp_mb();
1741 }
1742
1743 static bool img_request_child_test(struct rbd_img_request *img_request)
1744 {
1745         smp_mb();
1746         return test_bit(IMG_REQ_CHILD, &img_request->flags) != 0;
1747 }
1748
1749 static void img_request_layered_set(struct rbd_img_request *img_request)
1750 {
1751         set_bit(IMG_REQ_LAYERED, &img_request->flags);
1752         smp_mb();
1753 }
1754
1755 static void img_request_layered_clear(struct rbd_img_request *img_request)
1756 {
1757         clear_bit(IMG_REQ_LAYERED, &img_request->flags);
1758         smp_mb();
1759 }
1760
1761 static bool img_request_layered_test(struct rbd_img_request *img_request)
1762 {
1763         smp_mb();
1764         return test_bit(IMG_REQ_LAYERED, &img_request->flags) != 0;
1765 }
1766
1767 static enum obj_operation_type
1768 rbd_img_request_op_type(struct rbd_img_request *img_request)
1769 {
1770         if (img_request_write_test(img_request))
1771                 return OBJ_OP_WRITE;
1772         else if (img_request_discard_test(img_request))
1773                 return OBJ_OP_DISCARD;
1774         else
1775                 return OBJ_OP_READ;
1776 }
1777
1778 static void
1779 rbd_img_obj_request_read_callback(struct rbd_obj_request *obj_request)
1780 {
1781         u64 xferred = obj_request->xferred;
1782         u64 length = obj_request->length;
1783
1784         dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1785                 obj_request, obj_request->img_request, obj_request->result,
1786                 xferred, length);
1787         /*
1788          * ENOENT means a hole in the image.  We zero-fill the entire
1789          * length of the request.  A short read also implies zero-fill
1790          * to the end of the request.  An error requires the whole
1791          * length of the request to be reported finished with an error
1792          * to the block layer.  In each case we update the xferred
1793          * count to indicate the whole request was satisfied.
1794          */
1795         rbd_assert(obj_request->type != OBJ_REQUEST_NODATA);
1796         if (obj_request->result == -ENOENT) {
1797                 if (obj_request->type == OBJ_REQUEST_BIO)
1798                         zero_bio_chain(obj_request->bio_list, 0);
1799                 else
1800                         zero_pages(obj_request->pages, 0, length);
1801                 obj_request->result = 0;
1802         } else if (xferred < length && !obj_request->result) {
1803                 if (obj_request->type == OBJ_REQUEST_BIO)
1804                         zero_bio_chain(obj_request->bio_list, xferred);
1805                 else
1806                         zero_pages(obj_request->pages, xferred, length);
1807         }
1808         obj_request->xferred = length;
1809         obj_request_done_set(obj_request);
1810 }
1811
1812 static void rbd_obj_request_complete(struct rbd_obj_request *obj_request)
1813 {
1814         dout("%s: obj %p cb %p\n", __func__, obj_request,
1815                 obj_request->callback);
1816         if (obj_request->callback)
1817                 obj_request->callback(obj_request);
1818         else
1819                 complete_all(&obj_request->completion);
1820 }
1821
1822 static void rbd_osd_read_callback(struct rbd_obj_request *obj_request)
1823 {
1824         struct rbd_img_request *img_request = NULL;
1825         struct rbd_device *rbd_dev = NULL;
1826         bool layered = false;
1827
1828         if (obj_request_img_data_test(obj_request)) {
1829                 img_request = obj_request->img_request;
1830                 layered = img_request && img_request_layered_test(img_request);
1831                 rbd_dev = img_request->rbd_dev;
1832         }
1833
1834         dout("%s: obj %p img %p result %d %llu/%llu\n", __func__,
1835                 obj_request, img_request, obj_request->result,
1836                 obj_request->xferred, obj_request->length);
1837         if (layered && obj_request->result == -ENOENT &&
1838                         obj_request->img_offset < rbd_dev->parent_overlap)
1839                 rbd_img_parent_read(obj_request);
1840         else if (img_request)
1841                 rbd_img_obj_request_read_callback(obj_request);
1842         else
1843                 obj_request_done_set(obj_request);
1844 }
1845
1846 static void rbd_osd_write_callback(struct rbd_obj_request *obj_request)
1847 {
1848         dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1849                 obj_request->result, obj_request->length);
1850         /*
1851          * There is no such thing as a successful short write.  Set
1852          * it to our originally-requested length.
1853          */
1854         obj_request->xferred = obj_request->length;
1855         obj_request_done_set(obj_request);
1856 }
1857
1858 static void rbd_osd_discard_callback(struct rbd_obj_request *obj_request)
1859 {
1860         dout("%s: obj %p result %d %llu\n", __func__, obj_request,
1861                 obj_request->result, obj_request->length);
1862         /*
1863          * There is no such thing as a successful short discard.  Set
1864          * it to our originally-requested length.
1865          */
1866         obj_request->xferred = obj_request->length;
1867         /* discarding a non-existent object is not a problem */
1868         if (obj_request->result == -ENOENT)
1869                 obj_request->result = 0;
1870         obj_request_done_set(obj_request);
1871 }
1872
1873 /*
1874  * For a simple stat call there's nothing to do.  We'll do more if
1875  * this is part of a write sequence for a layered image.
1876  */
1877 static void rbd_osd_stat_callback(struct rbd_obj_request *obj_request)
1878 {
1879         dout("%s: obj %p\n", __func__, obj_request);
1880         obj_request_done_set(obj_request);
1881 }
1882
1883 static void rbd_osd_call_callback(struct rbd_obj_request *obj_request)
1884 {
1885         dout("%s: obj %p\n", __func__, obj_request);
1886
1887         if (obj_request_img_data_test(obj_request))
1888                 rbd_osd_copyup_callback(obj_request);
1889         else
1890                 obj_request_done_set(obj_request);
1891 }
1892
1893 static void rbd_osd_req_callback(struct ceph_osd_request *osd_req)
1894 {
1895         struct rbd_obj_request *obj_request = osd_req->r_priv;
1896         u16 opcode;
1897
1898         dout("%s: osd_req %p\n", __func__, osd_req);
1899         rbd_assert(osd_req == obj_request->osd_req);
1900         if (obj_request_img_data_test(obj_request)) {
1901                 rbd_assert(obj_request->img_request);
1902                 rbd_assert(obj_request->which != BAD_WHICH);
1903         } else {
1904                 rbd_assert(obj_request->which == BAD_WHICH);
1905         }
1906
1907         if (osd_req->r_result < 0)
1908                 obj_request->result = osd_req->r_result;
1909
1910         /*
1911          * We support a 64-bit length, but ultimately it has to be
1912          * passed to the block layer, which just supports a 32-bit
1913          * length field.
1914          */
1915         obj_request->xferred = osd_req->r_ops[0].outdata_len;
1916         rbd_assert(obj_request->xferred < (u64)UINT_MAX);
1917
1918         opcode = osd_req->r_ops[0].op;
1919         switch (opcode) {
1920         case CEPH_OSD_OP_READ:
1921                 rbd_osd_read_callback(obj_request);
1922                 break;
1923         case CEPH_OSD_OP_SETALLOCHINT:
1924                 rbd_assert(osd_req->r_ops[1].op == CEPH_OSD_OP_WRITE ||
1925                            osd_req->r_ops[1].op == CEPH_OSD_OP_WRITEFULL);
1926                 /* fall through */
1927         case CEPH_OSD_OP_WRITE:
1928         case CEPH_OSD_OP_WRITEFULL:
1929                 rbd_osd_write_callback(obj_request);
1930                 break;
1931         case CEPH_OSD_OP_STAT:
1932                 rbd_osd_stat_callback(obj_request);
1933                 break;
1934         case CEPH_OSD_OP_DELETE:
1935         case CEPH_OSD_OP_TRUNCATE:
1936         case CEPH_OSD_OP_ZERO:
1937                 rbd_osd_discard_callback(obj_request);
1938                 break;
1939         case CEPH_OSD_OP_CALL:
1940                 rbd_osd_call_callback(obj_request);
1941                 break;
1942         default:
1943                 rbd_warn(NULL, "%s: unsupported op %hu",
1944                         obj_request->object_name, (unsigned short) opcode);
1945                 break;
1946         }
1947
1948         if (obj_request_done_test(obj_request))
1949                 rbd_obj_request_complete(obj_request);
1950 }
1951
1952 static void rbd_osd_req_format_read(struct rbd_obj_request *obj_request)
1953 {
1954         struct ceph_osd_request *osd_req = obj_request->osd_req;
1955
1956         rbd_assert(obj_request_img_data_test(obj_request));
1957         osd_req->r_snapid = obj_request->img_request->snap_id;
1958 }
1959
1960 static void rbd_osd_req_format_write(struct rbd_obj_request *obj_request)
1961 {
1962         struct ceph_osd_request *osd_req = obj_request->osd_req;
1963
1964         osd_req->r_mtime = CURRENT_TIME;
1965         osd_req->r_data_offset = obj_request->offset;
1966 }
1967
1968 /*
1969  * Create an osd request.  A read request has one osd op (read).
1970  * A write request has either one (watch) or two (hint+write) osd ops.
1971  * (All rbd data writes are prefixed with an allocation hint op, but
1972  * technically osd watch is a write request, hence this distinction.)
1973  */
1974 static struct ceph_osd_request *rbd_osd_req_create(
1975                                         struct rbd_device *rbd_dev,
1976                                         enum obj_operation_type op_type,
1977                                         unsigned int num_ops,
1978                                         struct rbd_obj_request *obj_request)
1979 {
1980         struct ceph_snap_context *snapc = NULL;
1981         struct ceph_osd_client *osdc;
1982         struct ceph_osd_request *osd_req;
1983
1984         if (obj_request_img_data_test(obj_request) &&
1985                 (op_type == OBJ_OP_DISCARD || op_type == OBJ_OP_WRITE)) {
1986                 struct rbd_img_request *img_request = obj_request->img_request;
1987                 if (op_type == OBJ_OP_WRITE) {
1988                         rbd_assert(img_request_write_test(img_request));
1989                 } else {
1990                         rbd_assert(img_request_discard_test(img_request));
1991                 }
1992                 snapc = img_request->snapc;
1993         }
1994
1995         rbd_assert(num_ops == 1 || ((op_type == OBJ_OP_WRITE) && num_ops == 2));
1996
1997         /* Allocate and initialize the request, for the num_ops ops */
1998
1999         osdc = &rbd_dev->rbd_client->client->osdc;
2000         osd_req = ceph_osdc_alloc_request(osdc, snapc, num_ops, false,
2001                                           GFP_NOIO);
2002         if (!osd_req)
2003                 goto fail;
2004
2005         if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
2006                 osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
2007         else
2008                 osd_req->r_flags = CEPH_OSD_FLAG_READ;
2009
2010         osd_req->r_callback = rbd_osd_req_callback;
2011         osd_req->r_priv = obj_request;
2012
2013         osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2014         if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
2015                              obj_request->object_name))
2016                 goto fail;
2017
2018         if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
2019                 goto fail;
2020
2021         return osd_req;
2022
2023 fail:
2024         ceph_osdc_put_request(osd_req);
2025         return NULL;
2026 }
2027
2028 /*
2029  * Create a copyup osd request based on the information in the object
2030  * request supplied.  A copyup request has two or three osd ops, a
2031  * copyup method call, potentially a hint op, and a write or truncate
2032  * or zero op.
2033  */
2034 static struct ceph_osd_request *
2035 rbd_osd_req_create_copyup(struct rbd_obj_request *obj_request)
2036 {
2037         struct rbd_img_request *img_request;
2038         struct ceph_snap_context *snapc;
2039         struct rbd_device *rbd_dev;
2040         struct ceph_osd_client *osdc;
2041         struct ceph_osd_request *osd_req;
2042         int num_osd_ops = 3;
2043
2044         rbd_assert(obj_request_img_data_test(obj_request));
2045         img_request = obj_request->img_request;
2046         rbd_assert(img_request);
2047         rbd_assert(img_request_write_test(img_request) ||
2048                         img_request_discard_test(img_request));
2049
2050         if (img_request_discard_test(img_request))
2051                 num_osd_ops = 2;
2052
2053         /* Allocate and initialize the request, for all the ops */
2054
2055         snapc = img_request->snapc;
2056         rbd_dev = img_request->rbd_dev;
2057         osdc = &rbd_dev->rbd_client->client->osdc;
2058         osd_req = ceph_osdc_alloc_request(osdc, snapc, num_osd_ops,
2059                                                 false, GFP_NOIO);
2060         if (!osd_req)
2061                 goto fail;
2062
2063         osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
2064         osd_req->r_callback = rbd_osd_req_callback;
2065         osd_req->r_priv = obj_request;
2066
2067         osd_req->r_base_oloc.pool = rbd_dev->layout.pool_id;
2068         if (ceph_oid_aprintf(&osd_req->r_base_oid, GFP_NOIO, "%s",
2069                              obj_request->object_name))
2070                 goto fail;
2071
2072         if (ceph_osdc_alloc_messages(osd_req, GFP_NOIO))
2073                 goto fail;
2074
2075         return osd_req;
2076
2077 fail:
2078         ceph_osdc_put_request(osd_req);
2079         return NULL;
2080 }
2081
2082
2083 static void rbd_osd_req_destroy(struct ceph_osd_request *osd_req)
2084 {
2085         ceph_osdc_put_request(osd_req);
2086 }
2087
2088 /* object_name is assumed to be a non-null pointer and NUL-terminated */
2089
2090 static struct rbd_obj_request *rbd_obj_request_create(const char *object_name,
2091                                                 u64 offset, u64 length,
2092                                                 enum obj_request_type type)
2093 {
2094         struct rbd_obj_request *obj_request;
2095         size_t size;
2096         char *name;
2097
2098         rbd_assert(obj_request_type_valid(type));
2099
2100         size = strlen(object_name) + 1;
2101         name = kmalloc(size, GFP_NOIO);
2102         if (!name)
2103                 return NULL;
2104
2105         obj_request = kmem_cache_zalloc(rbd_obj_request_cache, GFP_NOIO);
2106         if (!obj_request) {
2107                 kfree(name);
2108                 return NULL;
2109         }
2110
2111         obj_request->object_name = memcpy(name, object_name, size);
2112         obj_request->offset = offset;
2113         obj_request->length = length;
2114         obj_request->flags = 0;
2115         obj_request->which = BAD_WHICH;
2116         obj_request->type = type;
2117         INIT_LIST_HEAD(&obj_request->links);
2118         init_completion(&obj_request->completion);
2119         kref_init(&obj_request->kref);
2120
2121         dout("%s: \"%s\" %llu/%llu %d -> obj %p\n", __func__, object_name,
2122                 offset, length, (int)type, obj_request);
2123
2124         return obj_request;
2125 }
2126
2127 static void rbd_obj_request_destroy(struct kref *kref)
2128 {
2129         struct rbd_obj_request *obj_request;
2130
2131         obj_request = container_of(kref, struct rbd_obj_request, kref);
2132
2133         dout("%s: obj %p\n", __func__, obj_request);
2134
2135         rbd_assert(obj_request->img_request == NULL);
2136         rbd_assert(obj_request->which == BAD_WHICH);
2137
2138         if (obj_request->osd_req)
2139                 rbd_osd_req_destroy(obj_request->osd_req);
2140
2141         rbd_assert(obj_request_type_valid(obj_request->type));
2142         switch (obj_request->type) {
2143         case OBJ_REQUEST_NODATA:
2144                 break;          /* Nothing to do */
2145         case OBJ_REQUEST_BIO:
2146                 if (obj_request->bio_list)
2147                         bio_chain_put(obj_request->bio_list);
2148                 break;
2149         case OBJ_REQUEST_PAGES:
2150                 if (obj_request->pages)
2151                         ceph_release_page_vector(obj_request->pages,
2152                                                 obj_request->page_count);
2153                 break;
2154         }
2155
2156         kfree(obj_request->object_name);
2157         obj_request->object_name = NULL;
2158         kmem_cache_free(rbd_obj_request_cache, obj_request);
2159 }
2160
2161 /* It's OK to call this for a device with no parent */
2162
2163 static void rbd_spec_put(struct rbd_spec *spec);
2164 static void rbd_dev_unparent(struct rbd_device *rbd_dev)
2165 {
2166         rbd_dev_remove_parent(rbd_dev);
2167         rbd_spec_put(rbd_dev->parent_spec);
2168         rbd_dev->parent_spec = NULL;
2169         rbd_dev->parent_overlap = 0;
2170 }
2171
2172 /*
2173  * Parent image reference counting is used to determine when an
2174  * image's parent fields can be safely torn down--after there are no
2175  * more in-flight requests to the parent image.  When the last
2176  * reference is dropped, cleaning them up is safe.
2177  */
2178 static void rbd_dev_parent_put(struct rbd_device *rbd_dev)
2179 {
2180         int counter;
2181
2182         if (!rbd_dev->parent_spec)
2183                 return;
2184
2185         counter = atomic_dec_return_safe(&rbd_dev->parent_ref);
2186         if (counter > 0)
2187                 return;
2188
2189         /* Last reference; clean up parent data structures */
2190
2191         if (!counter)
2192                 rbd_dev_unparent(rbd_dev);
2193         else
2194                 rbd_warn(rbd_dev, "parent reference underflow");
2195 }
2196
2197 /*
2198  * If an image has a non-zero parent overlap, get a reference to its
2199  * parent.
2200  *
2201  * Returns true if the rbd device has a parent with a non-zero
2202  * overlap and a reference for it was successfully taken, or
2203  * false otherwise.
2204  */
2205 static bool rbd_dev_parent_get(struct rbd_device *rbd_dev)
2206 {
2207         int counter = 0;
2208
2209         if (!rbd_dev->parent_spec)
2210                 return false;
2211
2212         down_read(&rbd_dev->header_rwsem);
2213         if (rbd_dev->parent_overlap)
2214                 counter = atomic_inc_return_safe(&rbd_dev->parent_ref);
2215         up_read(&rbd_dev->header_rwsem);
2216
2217         if (counter < 0)
2218                 rbd_warn(rbd_dev, "parent reference overflow");
2219
2220         return counter > 0;
2221 }
2222
2223 /*
2224  * Caller is responsible for filling in the list of object requests
2225  * that comprises the image request, and the Linux request pointer
2226  * (if there is one).
2227  */
2228 static struct rbd_img_request *rbd_img_request_create(
2229                                         struct rbd_device *rbd_dev,
2230                                         u64 offset, u64 length,
2231                                         enum obj_operation_type op_type,
2232                                         struct ceph_snap_context *snapc)
2233 {
2234         struct rbd_img_request *img_request;
2235
2236         img_request = kmem_cache_alloc(rbd_img_request_cache, GFP_NOIO);
2237         if (!img_request)
2238                 return NULL;
2239
2240         img_request->rq = NULL;
2241         img_request->rbd_dev = rbd_dev;
2242         img_request->offset = offset;
2243         img_request->length = length;
2244         img_request->flags = 0;
2245         if (op_type == OBJ_OP_DISCARD) {
2246                 img_request_discard_set(img_request);
2247                 img_request->snapc = snapc;
2248         } else if (op_type == OBJ_OP_WRITE) {
2249                 img_request_write_set(img_request);
2250                 img_request->snapc = snapc;
2251         } else {
2252                 img_request->snap_id = rbd_dev->spec->snap_id;
2253         }
2254         if (rbd_dev_parent_get(rbd_dev))
2255                 img_request_layered_set(img_request);
2256         spin_lock_init(&img_request->completion_lock);
2257         img_request->next_completion = 0;
2258         img_request->callback = NULL;
2259         img_request->result = 0;
2260         img_request->obj_request_count = 0;
2261         INIT_LIST_HEAD(&img_request->obj_requests);
2262         kref_init(&img_request->kref);
2263
2264         dout("%s: rbd_dev %p %s %llu/%llu -> img %p\n", __func__, rbd_dev,
2265                 obj_op_name(op_type), offset, length, img_request);
2266
2267         return img_request;
2268 }
2269
2270 static void rbd_img_request_destroy(struct kref *kref)
2271 {
2272         struct rbd_img_request *img_request;
2273         struct rbd_obj_request *obj_request;
2274         struct rbd_obj_request *next_obj_request;
2275
2276         img_request = container_of(kref, struct rbd_img_request, kref);
2277
2278         dout("%s: img %p\n", __func__, img_request);
2279
2280         for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2281                 rbd_img_obj_request_del(img_request, obj_request);
2282         rbd_assert(img_request->obj_request_count == 0);
2283
2284         if (img_request_layered_test(img_request)) {
2285                 img_request_layered_clear(img_request);
2286                 rbd_dev_parent_put(img_request->rbd_dev);
2287         }
2288
2289         if (img_request_write_test(img_request) ||
2290                 img_request_discard_test(img_request))
2291                 ceph_put_snap_context(img_request->snapc);
2292
2293         kmem_cache_free(rbd_img_request_cache, img_request);
2294 }
2295
2296 static struct rbd_img_request *rbd_parent_request_create(
2297                                         struct rbd_obj_request *obj_request,
2298                                         u64 img_offset, u64 length)
2299 {
2300         struct rbd_img_request *parent_request;
2301         struct rbd_device *rbd_dev;
2302
2303         rbd_assert(obj_request->img_request);
2304         rbd_dev = obj_request->img_request->rbd_dev;
2305
2306         parent_request = rbd_img_request_create(rbd_dev->parent, img_offset,
2307                                                 length, OBJ_OP_READ, NULL);
2308         if (!parent_request)
2309                 return NULL;
2310
2311         img_request_child_set(parent_request);
2312         rbd_obj_request_get(obj_request);
2313         parent_request->obj_request = obj_request;
2314
2315         return parent_request;
2316 }
2317
2318 static void rbd_parent_request_destroy(struct kref *kref)
2319 {
2320         struct rbd_img_request *parent_request;
2321         struct rbd_obj_request *orig_request;
2322
2323         parent_request = container_of(kref, struct rbd_img_request, kref);
2324         orig_request = parent_request->obj_request;
2325
2326         parent_request->obj_request = NULL;
2327         rbd_obj_request_put(orig_request);
2328         img_request_child_clear(parent_request);
2329
2330         rbd_img_request_destroy(kref);
2331 }
2332
2333 static bool rbd_img_obj_end_request(struct rbd_obj_request *obj_request)
2334 {
2335         struct rbd_img_request *img_request;
2336         unsigned int xferred;
2337         int result;
2338         bool more;
2339
2340         rbd_assert(obj_request_img_data_test(obj_request));
2341         img_request = obj_request->img_request;
2342
2343         rbd_assert(obj_request->xferred <= (u64)UINT_MAX);
2344         xferred = (unsigned int)obj_request->xferred;
2345         result = obj_request->result;
2346         if (result) {
2347                 struct rbd_device *rbd_dev = img_request->rbd_dev;
2348                 enum obj_operation_type op_type;
2349
2350                 if (img_request_discard_test(img_request))
2351                         op_type = OBJ_OP_DISCARD;
2352                 else if (img_request_write_test(img_request))
2353                         op_type = OBJ_OP_WRITE;
2354                 else
2355                         op_type = OBJ_OP_READ;
2356
2357                 rbd_warn(rbd_dev, "%s %llx at %llx (%llx)",
2358                         obj_op_name(op_type), obj_request->length,
2359                         obj_request->img_offset, obj_request->offset);
2360                 rbd_warn(rbd_dev, "  result %d xferred %x",
2361                         result, xferred);
2362                 if (!img_request->result)
2363                         img_request->result = result;
2364                 /*
2365                  * Need to end I/O on the entire obj_request worth of
2366                  * bytes in case of error.
2367                  */
2368                 xferred = obj_request->length;
2369         }
2370
2371         /* Image object requests don't own their page array */
2372
2373         if (obj_request->type == OBJ_REQUEST_PAGES) {
2374                 obj_request->pages = NULL;
2375                 obj_request->page_count = 0;
2376         }
2377
2378         if (img_request_child_test(img_request)) {
2379                 rbd_assert(img_request->obj_request != NULL);
2380                 more = obj_request->which < img_request->obj_request_count - 1;
2381         } else {
2382                 rbd_assert(img_request->rq != NULL);
2383
2384                 more = blk_update_request(img_request->rq, result, xferred);
2385                 if (!more)
2386                         __blk_mq_end_request(img_request->rq, result);
2387         }
2388
2389         return more;
2390 }
2391
2392 static void rbd_img_obj_callback(struct rbd_obj_request *obj_request)
2393 {
2394         struct rbd_img_request *img_request;
2395         u32 which = obj_request->which;
2396         bool more = true;
2397
2398         rbd_assert(obj_request_img_data_test(obj_request));
2399         img_request = obj_request->img_request;
2400
2401         dout("%s: img %p obj %p\n", __func__, img_request, obj_request);
2402         rbd_assert(img_request != NULL);
2403         rbd_assert(img_request->obj_request_count > 0);
2404         rbd_assert(which != BAD_WHICH);
2405         rbd_assert(which < img_request->obj_request_count);
2406
2407         spin_lock_irq(&img_request->completion_lock);
2408         if (which != img_request->next_completion)
2409                 goto out;
2410
2411         for_each_obj_request_from(img_request, obj_request) {
2412                 rbd_assert(more);
2413                 rbd_assert(which < img_request->obj_request_count);
2414
2415                 if (!obj_request_done_test(obj_request))
2416                         break;
2417                 more = rbd_img_obj_end_request(obj_request);
2418                 which++;
2419         }
2420
2421         rbd_assert(more ^ (which == img_request->obj_request_count));
2422         img_request->next_completion = which;
2423 out:
2424         spin_unlock_irq(&img_request->completion_lock);
2425         rbd_img_request_put(img_request);
2426
2427         if (!more)
2428                 rbd_img_request_complete(img_request);
2429 }
2430
2431 /*
2432  * Add individual osd ops to the given ceph_osd_request and prepare
2433  * them for submission. num_ops is the current number of
2434  * osd operations already to the object request.
2435  */
2436 static void rbd_img_obj_request_fill(struct rbd_obj_request *obj_request,
2437                                 struct ceph_osd_request *osd_request,
2438                                 enum obj_operation_type op_type,
2439                                 unsigned int num_ops)
2440 {
2441         struct rbd_img_request *img_request = obj_request->img_request;
2442         struct rbd_device *rbd_dev = img_request->rbd_dev;
2443         u64 object_size = rbd_obj_bytes(&rbd_dev->header);
2444         u64 offset = obj_request->offset;
2445         u64 length = obj_request->length;
2446         u64 img_end;
2447         u16 opcode;
2448
2449         if (op_type == OBJ_OP_DISCARD) {
2450                 if (!offset && length == object_size &&
2451                     (!img_request_layered_test(img_request) ||
2452                      !obj_request_overlaps_parent(obj_request))) {
2453                         opcode = CEPH_OSD_OP_DELETE;
2454                 } else if ((offset + length == object_size)) {
2455                         opcode = CEPH_OSD_OP_TRUNCATE;
2456                 } else {
2457                         down_read(&rbd_dev->header_rwsem);
2458                         img_end = rbd_dev->header.image_size;
2459                         up_read(&rbd_dev->header_rwsem);
2460
2461                         if (obj_request->img_offset + length == img_end)
2462                                 opcode = CEPH_OSD_OP_TRUNCATE;
2463                         else
2464                                 opcode = CEPH_OSD_OP_ZERO;
2465                 }
2466         } else if (op_type == OBJ_OP_WRITE) {
2467                 if (!offset && length == object_size)
2468                         opcode = CEPH_OSD_OP_WRITEFULL;
2469                 else
2470                         opcode = CEPH_OSD_OP_WRITE;
2471                 osd_req_op_alloc_hint_init(osd_request, num_ops,
2472                                         object_size, object_size);
2473                 num_ops++;
2474         } else {
2475                 opcode = CEPH_OSD_OP_READ;
2476         }
2477
2478         if (opcode == CEPH_OSD_OP_DELETE)
2479                 osd_req_op_init(osd_request, num_ops, opcode, 0);
2480         else
2481                 osd_req_op_extent_init(osd_request, num_ops, opcode,
2482                                        offset, length, 0, 0);
2483
2484         if (obj_request->type == OBJ_REQUEST_BIO)
2485                 osd_req_op_extent_osd_data_bio(osd_request, num_ops,
2486                                         obj_request->bio_list, length);
2487         else if (obj_request->type == OBJ_REQUEST_PAGES)
2488                 osd_req_op_extent_osd_data_pages(osd_request, num_ops,
2489                                         obj_request->pages, length,
2490                                         offset & ~PAGE_MASK, false, false);
2491
2492         /* Discards are also writes */
2493         if (op_type == OBJ_OP_WRITE || op_type == OBJ_OP_DISCARD)
2494                 rbd_osd_req_format_write(obj_request);
2495         else
2496                 rbd_osd_req_format_read(obj_request);
2497 }
2498
2499 /*
2500  * Split up an image request into one or more object requests, each
2501  * to a different object.  The "type" parameter indicates whether
2502  * "data_desc" is the pointer to the head of a list of bio
2503  * structures, or the base of a page array.  In either case this
2504  * function assumes data_desc describes memory sufficient to hold
2505  * all data described by the image request.
2506  */
2507 static int rbd_img_request_fill(struct rbd_img_request *img_request,
2508                                         enum obj_request_type type,
2509                                         void *data_desc)
2510 {
2511         struct rbd_device *rbd_dev = img_request->rbd_dev;
2512         struct rbd_obj_request *obj_request = NULL;
2513         struct rbd_obj_request *next_obj_request;
2514         struct bio *bio_list = NULL;
2515         unsigned int bio_offset = 0;
2516         struct page **pages = NULL;
2517         enum obj_operation_type op_type;
2518         u64 img_offset;
2519         u64 resid;
2520
2521         dout("%s: img %p type %d data_desc %p\n", __func__, img_request,
2522                 (int)type, data_desc);
2523
2524         img_offset = img_request->offset;
2525         resid = img_request->length;
2526         rbd_assert(resid > 0);
2527         op_type = rbd_img_request_op_type(img_request);
2528
2529         if (type == OBJ_REQUEST_BIO) {
2530                 bio_list = data_desc;
2531                 rbd_assert(img_offset ==
2532                            bio_list->bi_iter.bi_sector << SECTOR_SHIFT);
2533         } else if (type == OBJ_REQUEST_PAGES) {
2534                 pages = data_desc;
2535         }
2536
2537         while (resid) {
2538                 struct ceph_osd_request *osd_req;
2539                 const char *object_name;
2540                 u64 offset;
2541                 u64 length;
2542
2543                 object_name = rbd_segment_name(rbd_dev, img_offset);
2544                 if (!object_name)
2545                         goto out_unwind;
2546                 offset = rbd_segment_offset(rbd_dev, img_offset);
2547                 length = rbd_segment_length(rbd_dev, img_offset, resid);
2548                 obj_request = rbd_obj_request_create(object_name,
2549                                                 offset, length, type);
2550                 /* object request has its own copy of the object name */
2551                 rbd_segment_name_free(object_name);
2552                 if (!obj_request)
2553                         goto out_unwind;
2554
2555                 /*
2556                  * set obj_request->img_request before creating the
2557                  * osd_request so that it gets the right snapc
2558                  */
2559                 rbd_img_obj_request_add(img_request, obj_request);
2560
2561                 if (type == OBJ_REQUEST_BIO) {
2562                         unsigned int clone_size;
2563
2564                         rbd_assert(length <= (u64)UINT_MAX);
2565                         clone_size = (unsigned int)length;
2566                         obj_request->bio_list =
2567                                         bio_chain_clone_range(&bio_list,
2568                                                                 &bio_offset,
2569                                                                 clone_size,
2570                                                                 GFP_NOIO);
2571                         if (!obj_request->bio_list)
2572                                 goto out_unwind;
2573                 } else if (type == OBJ_REQUEST_PAGES) {
2574                         unsigned int page_count;
2575
2576                         obj_request->pages = pages;
2577                         page_count = (u32)calc_pages_for(offset, length);
2578                         obj_request->page_count = page_count;
2579                         if ((offset + length) & ~PAGE_MASK)
2580                                 page_count--;   /* more on last page */
2581                         pages += page_count;
2582                 }
2583
2584                 osd_req = rbd_osd_req_create(rbd_dev, op_type,
2585                                         (op_type == OBJ_OP_WRITE) ? 2 : 1,
2586                                         obj_request);
2587                 if (!osd_req)
2588                         goto out_unwind;
2589
2590                 obj_request->osd_req = osd_req;
2591                 obj_request->callback = rbd_img_obj_callback;
2592                 obj_request->img_offset = img_offset;
2593
2594                 rbd_img_obj_request_fill(obj_request, osd_req, op_type, 0);
2595
2596                 img_offset += length;
2597                 resid -= length;
2598         }
2599
2600         return 0;
2601
2602 out_unwind:
2603         for_each_obj_request_safe(img_request, obj_request, next_obj_request)
2604                 rbd_img_obj_request_del(img_request, obj_request);
2605
2606         return -ENOMEM;
2607 }
2608
2609 static void
2610 rbd_osd_copyup_callback(struct rbd_obj_request *obj_request)
2611 {
2612         struct rbd_img_request *img_request;
2613         struct rbd_device *rbd_dev;
2614         struct page **pages;
2615         u32 page_count;
2616
2617         dout("%s: obj %p\n", __func__, obj_request);
2618
2619         rbd_assert(obj_request->type == OBJ_REQUEST_BIO ||
2620                 obj_request->type == OBJ_REQUEST_NODATA);
2621         rbd_assert(obj_request_img_data_test(obj_request));
2622         img_request = obj_request->img_request;
2623         rbd_assert(img_request);
2624
2625         rbd_dev = img_request->rbd_dev;
2626         rbd_assert(rbd_dev);
2627
2628         pages = obj_request->copyup_pages;
2629         rbd_assert(pages != NULL);
2630         obj_request->copyup_pages = NULL;
2631         page_count = obj_request->copyup_page_count;
2632         rbd_assert(page_count);
2633         obj_request->copyup_page_count = 0;
2634         ceph_release_page_vector(pages, page_count);
2635
2636         /*
2637          * We want the transfer count to reflect the size of the
2638          * original write request.  There is no such thing as a
2639          * successful short write, so if the request was successful
2640          * we can just set it to the originally-requested length.
2641          */
2642         if (!obj_request->result)
2643                 obj_request->xferred = obj_request->length;
2644
2645         obj_request_done_set(obj_request);
2646 }
2647
2648 static void
2649 rbd_img_obj_parent_read_full_callback(struct rbd_img_request *img_request)
2650 {
2651         struct rbd_obj_request *orig_request;
2652         struct ceph_osd_request *osd_req;
2653         struct rbd_device *rbd_dev;
2654         struct page **pages;
2655         enum obj_operation_type op_type;
2656         u32 page_count;
2657         int img_result;
2658         u64 parent_length;
2659
2660         rbd_assert(img_request_child_test(img_request));
2661
2662         /* First get what we need from the image request */
2663
2664         pages = img_request->copyup_pages;
2665         rbd_assert(pages != NULL);
2666         img_request->copyup_pages = NULL;
2667         page_count = img_request->copyup_page_count;
2668         rbd_assert(page_count);
2669         img_request->copyup_page_count = 0;
2670
2671         orig_request = img_request->obj_request;
2672         rbd_assert(orig_request != NULL);
2673         rbd_assert(obj_request_type_valid(orig_request->type));
2674         img_result = img_request->result;
2675         parent_length = img_request->length;
2676         rbd_assert(img_result || parent_length == img_request->xferred);
2677         rbd_img_request_put(img_request);
2678
2679         rbd_assert(orig_request->img_request);
2680         rbd_dev = orig_request->img_request->rbd_dev;
2681         rbd_assert(rbd_dev);
2682
2683         /*
2684          * If the overlap has become 0 (most likely because the
2685          * image has been flattened) we need to free the pages
2686          * and re-submit the original write request.
2687          */
2688         if (!rbd_dev->parent_overlap) {
2689                 ceph_release_page_vector(pages, page_count);
2690                 rbd_obj_request_submit(orig_request);
2691                 return;
2692         }
2693
2694         if (img_result)
2695                 goto out_err;
2696
2697         /*
2698          * The original osd request is of no use to use any more.
2699          * We need a new one that can hold the three ops in a copyup
2700          * request.  Allocate the new copyup osd request for the
2701          * original request, and release the old one.
2702          */
2703         img_result = -ENOMEM;
2704         osd_req = rbd_osd_req_create_copyup(orig_request);
2705         if (!osd_req)
2706                 goto out_err;
2707         rbd_osd_req_destroy(orig_request->osd_req);
2708         orig_request->osd_req = osd_req;
2709         orig_request->copyup_pages = pages;
2710         orig_request->copyup_page_count = page_count;
2711
2712         /* Initialize the copyup op */
2713
2714         osd_req_op_cls_init(osd_req, 0, CEPH_OSD_OP_CALL, "rbd", "copyup");
2715         osd_req_op_cls_request_data_pages(osd_req, 0, pages, parent_length, 0,
2716                                                 false, false);
2717
2718         /* Add the other op(s) */
2719
2720         op_type = rbd_img_request_op_type(orig_request->img_request);
2721         rbd_img_obj_request_fill(orig_request, osd_req, op_type, 1);
2722
2723         /* All set, send it off. */
2724
2725         rbd_obj_request_submit(orig_request);
2726         return;
2727
2728 out_err:
2729         ceph_release_page_vector(pages, page_count);
2730         orig_request->result = img_result;
2731         orig_request->xferred = 0;
2732         rbd_img_request_get(orig_request->img_request);
2733         obj_request_done_set(orig_request);
2734         rbd_obj_request_complete(orig_request);
2735 }
2736
2737 /*
2738  * Read from the parent image the range of data that covers the
2739  * entire target of the given object request.  This is used for
2740  * satisfying a layered image write request when the target of an
2741  * object request from the image request does not exist.
2742  *
2743  * A page array big enough to hold the returned data is allocated
2744  * and supplied to rbd_img_request_fill() as the "data descriptor."
2745  * When the read completes, this page array will be transferred to
2746  * the original object request for the copyup operation.
2747  *
2748  * If an error occurs, it is recorded as the result of the original
2749  * object request in rbd_img_obj_exists_callback().
2750  */
2751 static int rbd_img_obj_parent_read_full(struct rbd_obj_request *obj_request)
2752 {
2753         struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2754         struct rbd_img_request *parent_request = NULL;
2755         u64 img_offset;
2756         u64 length;
2757         struct page **pages = NULL;
2758         u32 page_count;
2759         int result;
2760
2761         rbd_assert(rbd_dev->parent != NULL);
2762
2763         /*
2764          * Determine the byte range covered by the object in the
2765          * child image to which the original request was to be sent.
2766          */
2767         img_offset = obj_request->img_offset - obj_request->offset;
2768         length = (u64)1 << rbd_dev->header.obj_order;
2769
2770         /*
2771          * There is no defined parent data beyond the parent
2772          * overlap, so limit what we read at that boundary if
2773          * necessary.
2774          */
2775         if (img_offset + length > rbd_dev->parent_overlap) {
2776                 rbd_assert(img_offset < rbd_dev->parent_overlap);
2777                 length = rbd_dev->parent_overlap - img_offset;
2778         }
2779
2780         /*
2781          * Allocate a page array big enough to receive the data read
2782          * from the parent.
2783          */
2784         page_count = (u32)calc_pages_for(0, length);
2785         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2786         if (IS_ERR(pages)) {
2787                 result = PTR_ERR(pages);
2788                 pages = NULL;
2789                 goto out_err;
2790         }
2791
2792         result = -ENOMEM;
2793         parent_request = rbd_parent_request_create(obj_request,
2794                                                 img_offset, length);
2795         if (!parent_request)
2796                 goto out_err;
2797
2798         result = rbd_img_request_fill(parent_request, OBJ_REQUEST_PAGES, pages);
2799         if (result)
2800                 goto out_err;
2801
2802         parent_request->copyup_pages = pages;
2803         parent_request->copyup_page_count = page_count;
2804         parent_request->callback = rbd_img_obj_parent_read_full_callback;
2805
2806         result = rbd_img_request_submit(parent_request);
2807         if (!result)
2808                 return 0;
2809
2810         parent_request->copyup_pages = NULL;
2811         parent_request->copyup_page_count = 0;
2812         parent_request->obj_request = NULL;
2813         rbd_obj_request_put(obj_request);
2814 out_err:
2815         if (pages)
2816                 ceph_release_page_vector(pages, page_count);
2817         if (parent_request)
2818                 rbd_img_request_put(parent_request);
2819         return result;
2820 }
2821
2822 static void rbd_img_obj_exists_callback(struct rbd_obj_request *obj_request)
2823 {
2824         struct rbd_obj_request *orig_request;
2825         struct rbd_device *rbd_dev;
2826         int result;
2827
2828         rbd_assert(!obj_request_img_data_test(obj_request));
2829
2830         /*
2831          * All we need from the object request is the original
2832          * request and the result of the STAT op.  Grab those, then
2833          * we're done with the request.
2834          */
2835         orig_request = obj_request->obj_request;
2836         obj_request->obj_request = NULL;
2837         rbd_obj_request_put(orig_request);
2838         rbd_assert(orig_request);
2839         rbd_assert(orig_request->img_request);
2840
2841         result = obj_request->result;
2842         obj_request->result = 0;
2843
2844         dout("%s: obj %p for obj %p result %d %llu/%llu\n", __func__,
2845                 obj_request, orig_request, result,
2846                 obj_request->xferred, obj_request->length);
2847         rbd_obj_request_put(obj_request);
2848
2849         /*
2850          * If the overlap has become 0 (most likely because the
2851          * image has been flattened) we need to re-submit the
2852          * original request.
2853          */
2854         rbd_dev = orig_request->img_request->rbd_dev;
2855         if (!rbd_dev->parent_overlap) {
2856                 rbd_obj_request_submit(orig_request);
2857                 return;
2858         }
2859
2860         /*
2861          * Our only purpose here is to determine whether the object
2862          * exists, and we don't want to treat the non-existence as
2863          * an error.  If something else comes back, transfer the
2864          * error to the original request and complete it now.
2865          */
2866         if (!result) {
2867                 obj_request_existence_set(orig_request, true);
2868         } else if (result == -ENOENT) {
2869                 obj_request_existence_set(orig_request, false);
2870         } else {
2871                 goto fail_orig_request;
2872         }
2873
2874         /*
2875          * Resubmit the original request now that we have recorded
2876          * whether the target object exists.
2877          */
2878         result = rbd_img_obj_request_submit(orig_request);
2879         if (result)
2880                 goto fail_orig_request;
2881
2882         return;
2883
2884 fail_orig_request:
2885         orig_request->result = result;
2886         orig_request->xferred = 0;
2887         rbd_img_request_get(orig_request->img_request);
2888         obj_request_done_set(orig_request);
2889         rbd_obj_request_complete(orig_request);
2890 }
2891
2892 static int rbd_img_obj_exists_submit(struct rbd_obj_request *obj_request)
2893 {
2894         struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
2895         struct rbd_obj_request *stat_request;
2896         struct page **pages;
2897         u32 page_count;
2898         size_t size;
2899         int ret;
2900
2901         stat_request = rbd_obj_request_create(obj_request->object_name, 0, 0,
2902                                               OBJ_REQUEST_PAGES);
2903         if (!stat_request)
2904                 return -ENOMEM;
2905
2906         stat_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
2907                                                    stat_request);
2908         if (!stat_request->osd_req) {
2909                 ret = -ENOMEM;
2910                 goto fail_stat_request;
2911         }
2912
2913         /*
2914          * The response data for a STAT call consists of:
2915          *     le64 length;
2916          *     struct {
2917          *         le32 tv_sec;
2918          *         le32 tv_nsec;
2919          *     } mtime;
2920          */
2921         size = sizeof (__le64) + sizeof (__le32) + sizeof (__le32);
2922         page_count = (u32)calc_pages_for(0, size);
2923         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
2924         if (IS_ERR(pages)) {
2925                 ret = PTR_ERR(pages);
2926                 goto fail_stat_request;
2927         }
2928
2929         osd_req_op_init(stat_request->osd_req, 0, CEPH_OSD_OP_STAT, 0);
2930         osd_req_op_raw_data_in_pages(stat_request->osd_req, 0, pages, size, 0,
2931                                      false, false);
2932
2933         rbd_obj_request_get(obj_request);
2934         stat_request->obj_request = obj_request;
2935         stat_request->pages = pages;
2936         stat_request->page_count = page_count;
2937         stat_request->callback = rbd_img_obj_exists_callback;
2938
2939         rbd_obj_request_submit(stat_request);
2940         return 0;
2941
2942 fail_stat_request:
2943         rbd_obj_request_put(stat_request);
2944         return ret;
2945 }
2946
2947 static bool img_obj_request_simple(struct rbd_obj_request *obj_request)
2948 {
2949         struct rbd_img_request *img_request = obj_request->img_request;
2950         struct rbd_device *rbd_dev = img_request->rbd_dev;
2951
2952         /* Reads */
2953         if (!img_request_write_test(img_request) &&
2954             !img_request_discard_test(img_request))
2955                 return true;
2956
2957         /* Non-layered writes */
2958         if (!img_request_layered_test(img_request))
2959                 return true;
2960
2961         /*
2962          * Layered writes outside of the parent overlap range don't
2963          * share any data with the parent.
2964          */
2965         if (!obj_request_overlaps_parent(obj_request))
2966                 return true;
2967
2968         /*
2969          * Entire-object layered writes - we will overwrite whatever
2970          * parent data there is anyway.
2971          */
2972         if (!obj_request->offset &&
2973             obj_request->length == rbd_obj_bytes(&rbd_dev->header))
2974                 return true;
2975
2976         /*
2977          * If the object is known to already exist, its parent data has
2978          * already been copied.
2979          */
2980         if (obj_request_known_test(obj_request) &&
2981             obj_request_exists_test(obj_request))
2982                 return true;
2983
2984         return false;
2985 }
2986
2987 static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
2988 {
2989         rbd_assert(obj_request_img_data_test(obj_request));
2990         rbd_assert(obj_request_type_valid(obj_request->type));
2991         rbd_assert(obj_request->img_request);
2992
2993         if (img_obj_request_simple(obj_request)) {
2994                 rbd_obj_request_submit(obj_request);
2995                 return 0;
2996         }
2997
2998         /*
2999          * It's a layered write.  The target object might exist but
3000          * we may not know that yet.  If we know it doesn't exist,
3001          * start by reading the data for the full target object from
3002          * the parent so we can use it for a copyup to the target.
3003          */
3004         if (obj_request_known_test(obj_request))
3005                 return rbd_img_obj_parent_read_full(obj_request);
3006
3007         /* We don't know whether the target exists.  Go find out. */
3008
3009         return rbd_img_obj_exists_submit(obj_request);
3010 }
3011
3012 static int rbd_img_request_submit(struct rbd_img_request *img_request)
3013 {
3014         struct rbd_obj_request *obj_request;
3015         struct rbd_obj_request *next_obj_request;
3016         int ret = 0;
3017
3018         dout("%s: img %p\n", __func__, img_request);
3019
3020         rbd_img_request_get(img_request);
3021         for_each_obj_request_safe(img_request, obj_request, next_obj_request) {
3022                 ret = rbd_img_obj_request_submit(obj_request);
3023                 if (ret)
3024                         goto out_put_ireq;
3025         }
3026
3027 out_put_ireq:
3028         rbd_img_request_put(img_request);
3029         return ret;
3030 }
3031
3032 static void rbd_img_parent_read_callback(struct rbd_img_request *img_request)
3033 {
3034         struct rbd_obj_request *obj_request;
3035         struct rbd_device *rbd_dev;
3036         u64 obj_end;
3037         u64 img_xferred;
3038         int img_result;
3039
3040         rbd_assert(img_request_child_test(img_request));
3041
3042         /* First get what we need from the image request and release it */
3043
3044         obj_request = img_request->obj_request;
3045         img_xferred = img_request->xferred;
3046         img_result = img_request->result;
3047         rbd_img_request_put(img_request);
3048
3049         /*
3050          * If the overlap has become 0 (most likely because the
3051          * image has been flattened) we need to re-submit the
3052          * original request.
3053          */
3054         rbd_assert(obj_request);
3055         rbd_assert(obj_request->img_request);
3056         rbd_dev = obj_request->img_request->rbd_dev;
3057         if (!rbd_dev->parent_overlap) {
3058                 rbd_obj_request_submit(obj_request);
3059                 return;
3060         }
3061
3062         obj_request->result = img_result;
3063         if (obj_request->result)
3064                 goto out;
3065
3066         /*
3067          * We need to zero anything beyond the parent overlap
3068          * boundary.  Since rbd_img_obj_request_read_callback()
3069          * will zero anything beyond the end of a short read, an
3070          * easy way to do this is to pretend the data from the
3071          * parent came up short--ending at the overlap boundary.
3072          */
3073         rbd_assert(obj_request->img_offset < U64_MAX - obj_request->length);
3074         obj_end = obj_request->img_offset + obj_request->length;
3075         if (obj_end > rbd_dev->parent_overlap) {
3076                 u64 xferred = 0;
3077
3078                 if (obj_request->img_offset < rbd_dev->parent_overlap)
3079                         xferred = rbd_dev->parent_overlap -
3080                                         obj_request->img_offset;
3081
3082                 obj_request->xferred = min(img_xferred, xferred);
3083         } else {
3084                 obj_request->xferred = img_xferred;
3085         }
3086 out:
3087         rbd_img_obj_request_read_callback(obj_request);
3088         rbd_obj_request_complete(obj_request);
3089 }
3090
3091 static void rbd_img_parent_read(struct rbd_obj_request *obj_request)
3092 {
3093         struct rbd_img_request *img_request;
3094         int result;
3095
3096         rbd_assert(obj_request_img_data_test(obj_request));
3097         rbd_assert(obj_request->img_request != NULL);
3098         rbd_assert(obj_request->result == (s32) -ENOENT);
3099         rbd_assert(obj_request_type_valid(obj_request->type));
3100
3101         /* rbd_read_finish(obj_request, obj_request->length); */
3102         img_request = rbd_parent_request_create(obj_request,
3103                                                 obj_request->img_offset,
3104                                                 obj_request->length);
3105         result = -ENOMEM;
3106         if (!img_request)
3107                 goto out_err;
3108
3109         if (obj_request->type == OBJ_REQUEST_BIO)
3110                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
3111                                                 obj_request->bio_list);
3112         else
3113                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_PAGES,
3114                                                 obj_request->pages);
3115         if (result)
3116                 goto out_err;
3117
3118         img_request->callback = rbd_img_parent_read_callback;
3119         result = rbd_img_request_submit(img_request);
3120         if (result)
3121                 goto out_err;
3122
3123         return;
3124 out_err:
3125         if (img_request)
3126                 rbd_img_request_put(img_request);
3127         obj_request->result = result;
3128         obj_request->xferred = 0;
3129         obj_request_done_set(obj_request);
3130 }
3131
3132 static const struct rbd_client_id rbd_empty_cid;
3133
3134 static bool rbd_cid_equal(const struct rbd_client_id *lhs,
3135                           const struct rbd_client_id *rhs)
3136 {
3137         return lhs->gid == rhs->gid && lhs->handle == rhs->handle;
3138 }
3139
3140 static struct rbd_client_id rbd_get_cid(struct rbd_device *rbd_dev)
3141 {
3142         struct rbd_client_id cid;
3143
3144         mutex_lock(&rbd_dev->watch_mutex);
3145         cid.gid = ceph_client_gid(rbd_dev->rbd_client->client);
3146         cid.handle = rbd_dev->watch_cookie;
3147         mutex_unlock(&rbd_dev->watch_mutex);
3148         return cid;
3149 }
3150
3151 /*
3152  * lock_rwsem must be held for write
3153  */
3154 static void rbd_set_owner_cid(struct rbd_device *rbd_dev,
3155                               const struct rbd_client_id *cid)
3156 {
3157         dout("%s rbd_dev %p %llu-%llu -> %llu-%llu\n", __func__, rbd_dev,
3158              rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle,
3159              cid->gid, cid->handle);
3160         rbd_dev->owner_cid = *cid; /* struct */
3161 }
3162
3163 static void format_lock_cookie(struct rbd_device *rbd_dev, char *buf)
3164 {
3165         mutex_lock(&rbd_dev->watch_mutex);
3166         sprintf(buf, "%s %llu", RBD_LOCK_COOKIE_PREFIX, rbd_dev->watch_cookie);
3167         mutex_unlock(&rbd_dev->watch_mutex);
3168 }
3169
3170 /*
3171  * lock_rwsem must be held for write
3172  */
3173 static int rbd_lock(struct rbd_device *rbd_dev)
3174 {
3175         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3176         struct rbd_client_id cid = rbd_get_cid(rbd_dev);
3177         char cookie[32];
3178         int ret;
3179
3180         WARN_ON(__rbd_is_lock_owner(rbd_dev));
3181
3182         format_lock_cookie(rbd_dev, cookie);
3183         ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
3184                             RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
3185                             RBD_LOCK_TAG, "", 0);
3186         if (ret)
3187                 return ret;
3188
3189         rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
3190         rbd_set_owner_cid(rbd_dev, &cid);
3191         queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
3192         return 0;
3193 }
3194
3195 /*
3196  * lock_rwsem must be held for write
3197  */
3198 static int rbd_unlock(struct rbd_device *rbd_dev)
3199 {
3200         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3201         char cookie[32];
3202         int ret;
3203
3204         WARN_ON(!__rbd_is_lock_owner(rbd_dev));
3205
3206         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
3207
3208         format_lock_cookie(rbd_dev, cookie);
3209         ret = ceph_cls_unlock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
3210                               RBD_LOCK_NAME, cookie);
3211         if (ret && ret != -ENOENT) {
3212                 rbd_warn(rbd_dev, "cls_unlock failed: %d", ret);
3213                 return ret;
3214         }
3215
3216         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
3217         queue_work(rbd_dev->task_wq, &rbd_dev->released_lock_work);
3218         return 0;
3219 }
3220
3221 static int __rbd_notify_op_lock(struct rbd_device *rbd_dev,
3222                                 enum rbd_notify_op notify_op,
3223                                 struct page ***preply_pages,
3224                                 size_t *preply_len)
3225 {
3226         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3227         struct rbd_client_id cid = rbd_get_cid(rbd_dev);
3228         int buf_size = 4 + 8 + 8 + CEPH_ENCODING_START_BLK_LEN;
3229         char buf[buf_size];
3230         void *p = buf;
3231
3232         dout("%s rbd_dev %p notify_op %d\n", __func__, rbd_dev, notify_op);
3233
3234         /* encode *LockPayload NotifyMessage (op + ClientId) */
3235         ceph_start_encoding(&p, 2, 1, buf_size - CEPH_ENCODING_START_BLK_LEN);
3236         ceph_encode_32(&p, notify_op);
3237         ceph_encode_64(&p, cid.gid);
3238         ceph_encode_64(&p, cid.handle);
3239
3240         return ceph_osdc_notify(osdc, &rbd_dev->header_oid,
3241                                 &rbd_dev->header_oloc, buf, buf_size,
3242                                 RBD_NOTIFY_TIMEOUT, preply_pages, preply_len);
3243 }
3244
3245 static void rbd_notify_op_lock(struct rbd_device *rbd_dev,
3246                                enum rbd_notify_op notify_op)
3247 {
3248         struct page **reply_pages;
3249         size_t reply_len;
3250
3251         __rbd_notify_op_lock(rbd_dev, notify_op, &reply_pages, &reply_len);
3252         ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
3253 }
3254
3255 static void rbd_notify_acquired_lock(struct work_struct *work)
3256 {
3257         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3258                                                   acquired_lock_work);
3259
3260         rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_ACQUIRED_LOCK);
3261 }
3262
3263 static void rbd_notify_released_lock(struct work_struct *work)
3264 {
3265         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3266                                                   released_lock_work);
3267
3268         rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_RELEASED_LOCK);
3269 }
3270
3271 static int rbd_request_lock(struct rbd_device *rbd_dev)
3272 {
3273         struct page **reply_pages;
3274         size_t reply_len;
3275         bool lock_owner_responded = false;
3276         int ret;
3277
3278         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3279
3280         ret = __rbd_notify_op_lock(rbd_dev, RBD_NOTIFY_OP_REQUEST_LOCK,
3281                                    &reply_pages, &reply_len);
3282         if (ret && ret != -ETIMEDOUT) {
3283                 rbd_warn(rbd_dev, "failed to request lock: %d", ret);
3284                 goto out;
3285         }
3286
3287         if (reply_len > 0 && reply_len <= PAGE_SIZE) {
3288                 void *p = page_address(reply_pages[0]);
3289                 void *const end = p + reply_len;
3290                 u32 n;
3291
3292                 ceph_decode_32_safe(&p, end, n, e_inval); /* num_acks */
3293                 while (n--) {
3294                         u8 struct_v;
3295                         u32 len;
3296
3297                         ceph_decode_need(&p, end, 8 + 8, e_inval);
3298                         p += 8 + 8; /* skip gid and cookie */
3299
3300                         ceph_decode_32_safe(&p, end, len, e_inval);
3301                         if (!len)
3302                                 continue;
3303
3304                         if (lock_owner_responded) {
3305                                 rbd_warn(rbd_dev,
3306                                          "duplicate lock owners detected");
3307                                 ret = -EIO;
3308                                 goto out;
3309                         }
3310
3311                         lock_owner_responded = true;
3312                         ret = ceph_start_decoding(&p, end, 1, "ResponseMessage",
3313                                                   &struct_v, &len);
3314                         if (ret) {
3315                                 rbd_warn(rbd_dev,
3316                                          "failed to decode ResponseMessage: %d",
3317                                          ret);
3318                                 goto e_inval;
3319                         }
3320
3321                         ret = ceph_decode_32(&p);
3322                 }
3323         }
3324
3325         if (!lock_owner_responded) {
3326                 rbd_warn(rbd_dev, "no lock owners detected");
3327                 ret = -ETIMEDOUT;
3328         }
3329
3330 out:
3331         ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len));
3332         return ret;
3333
3334 e_inval:
3335         ret = -EINVAL;
3336         goto out;
3337 }
3338
3339 static void wake_requests(struct rbd_device *rbd_dev, bool wake_all)
3340 {
3341         dout("%s rbd_dev %p wake_all %d\n", __func__, rbd_dev, wake_all);
3342
3343         cancel_delayed_work(&rbd_dev->lock_dwork);
3344         if (wake_all)
3345                 wake_up_all(&rbd_dev->lock_waitq);
3346         else
3347                 wake_up(&rbd_dev->lock_waitq);
3348 }
3349
3350 static int get_lock_owner_info(struct rbd_device *rbd_dev,
3351                                struct ceph_locker **lockers, u32 *num_lockers)
3352 {
3353         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3354         u8 lock_type;
3355         char *lock_tag;
3356         int ret;
3357
3358         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3359
3360         ret = ceph_cls_lock_info(osdc, &rbd_dev->header_oid,
3361                                  &rbd_dev->header_oloc, RBD_LOCK_NAME,
3362                                  &lock_type, &lock_tag, lockers, num_lockers);
3363         if (ret)
3364                 return ret;
3365
3366         if (*num_lockers == 0) {
3367                 dout("%s rbd_dev %p no lockers detected\n", __func__, rbd_dev);
3368                 goto out;
3369         }
3370
3371         if (strcmp(lock_tag, RBD_LOCK_TAG)) {
3372                 rbd_warn(rbd_dev, "locked by external mechanism, tag %s",
3373                          lock_tag);
3374                 ret = -EBUSY;
3375                 goto out;
3376         }
3377
3378         if (lock_type == CEPH_CLS_LOCK_SHARED) {
3379                 rbd_warn(rbd_dev, "shared lock type detected");
3380                 ret = -EBUSY;
3381                 goto out;
3382         }
3383
3384         if (strncmp((*lockers)[0].id.cookie, RBD_LOCK_COOKIE_PREFIX,
3385                     strlen(RBD_LOCK_COOKIE_PREFIX))) {
3386                 rbd_warn(rbd_dev, "locked by external mechanism, cookie %s",
3387                          (*lockers)[0].id.cookie);
3388                 ret = -EBUSY;
3389                 goto out;
3390         }
3391
3392 out:
3393         kfree(lock_tag);
3394         return ret;
3395 }
3396
3397 static int find_watcher(struct rbd_device *rbd_dev,
3398                         const struct ceph_locker *locker)
3399 {
3400         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3401         struct ceph_watch_item *watchers;
3402         u32 num_watchers;
3403         u64 cookie;
3404         int i;
3405         int ret;
3406
3407         ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
3408                                       &rbd_dev->header_oloc, &watchers,
3409                                       &num_watchers);
3410         if (ret)
3411                 return ret;
3412
3413         sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
3414         for (i = 0; i < num_watchers; i++) {
3415                 if (!memcmp(&watchers[i].addr, &locker->info.addr,
3416                             sizeof(locker->info.addr)) &&
3417                     watchers[i].cookie == cookie) {
3418                         struct rbd_client_id cid = {
3419                                 .gid = le64_to_cpu(watchers[i].name.num),
3420                                 .handle = cookie,
3421                         };
3422
3423                         dout("%s rbd_dev %p found cid %llu-%llu\n", __func__,
3424                              rbd_dev, cid.gid, cid.handle);
3425                         rbd_set_owner_cid(rbd_dev, &cid);
3426                         ret = 1;
3427                         goto out;
3428                 }
3429         }
3430
3431         dout("%s rbd_dev %p no watchers\n", __func__, rbd_dev);
3432         ret = 0;
3433 out:
3434         kfree(watchers);
3435         return ret;
3436 }
3437
3438 /*
3439  * lock_rwsem must be held for write
3440  */
3441 static int rbd_try_lock(struct rbd_device *rbd_dev)
3442 {
3443         struct ceph_client *client = rbd_dev->rbd_client->client;
3444         struct ceph_locker *lockers;
3445         u32 num_lockers;
3446         int ret;
3447
3448         for (;;) {
3449                 ret = rbd_lock(rbd_dev);
3450                 if (ret != -EBUSY)
3451                         return ret;
3452
3453                 /* determine if the current lock holder is still alive */
3454                 ret = get_lock_owner_info(rbd_dev, &lockers, &num_lockers);
3455                 if (ret)
3456                         return ret;
3457
3458                 if (num_lockers == 0)
3459                         goto again;
3460
3461                 ret = find_watcher(rbd_dev, lockers);
3462                 if (ret) {
3463                         if (ret > 0)
3464                                 ret = 0; /* have to request lock */
3465                         goto out;
3466                 }
3467
3468                 rbd_warn(rbd_dev, "%s%llu seems dead, breaking lock",
3469                          ENTITY_NAME(lockers[0].id.name));
3470
3471                 ret = ceph_monc_blacklist_add(&client->monc,
3472                                               &lockers[0].info.addr);
3473                 if (ret) {
3474                         rbd_warn(rbd_dev, "blacklist of %s%llu failed: %d",
3475                                  ENTITY_NAME(lockers[0].id.name), ret);
3476                         goto out;
3477                 }
3478
3479                 ret = ceph_cls_break_lock(&client->osdc, &rbd_dev->header_oid,
3480                                           &rbd_dev->header_oloc, RBD_LOCK_NAME,
3481                                           lockers[0].id.cookie,
3482                                           &lockers[0].id.name);
3483                 if (ret && ret != -ENOENT)
3484                         goto out;
3485
3486 again:
3487                 ceph_free_lockers(lockers, num_lockers);
3488         }
3489
3490 out:
3491         ceph_free_lockers(lockers, num_lockers);
3492         return ret;
3493 }
3494
3495 /*
3496  * ret is set only if lock_state is RBD_LOCK_STATE_UNLOCKED
3497  */
3498 static enum rbd_lock_state rbd_try_acquire_lock(struct rbd_device *rbd_dev,
3499                                                 int *pret)
3500 {
3501         enum rbd_lock_state lock_state;
3502
3503         down_read(&rbd_dev->lock_rwsem);
3504         dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
3505              rbd_dev->lock_state);
3506         if (__rbd_is_lock_owner(rbd_dev)) {
3507                 lock_state = rbd_dev->lock_state;
3508                 up_read(&rbd_dev->lock_rwsem);
3509                 return lock_state;
3510         }
3511
3512         up_read(&rbd_dev->lock_rwsem);
3513         down_write(&rbd_dev->lock_rwsem);
3514         dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
3515              rbd_dev->lock_state);
3516         if (!__rbd_is_lock_owner(rbd_dev)) {
3517                 *pret = rbd_try_lock(rbd_dev);
3518                 if (*pret)
3519                         rbd_warn(rbd_dev, "failed to acquire lock: %d", *pret);
3520         }
3521
3522         lock_state = rbd_dev->lock_state;
3523         up_write(&rbd_dev->lock_rwsem);
3524         return lock_state;
3525 }
3526
3527 static void rbd_acquire_lock(struct work_struct *work)
3528 {
3529         struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
3530                                             struct rbd_device, lock_dwork);
3531         enum rbd_lock_state lock_state;
3532         int ret;
3533
3534         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3535 again:
3536         lock_state = rbd_try_acquire_lock(rbd_dev, &ret);
3537         if (lock_state != RBD_LOCK_STATE_UNLOCKED || ret == -EBLACKLISTED) {
3538                 if (lock_state == RBD_LOCK_STATE_LOCKED)
3539                         wake_requests(rbd_dev, true);
3540                 dout("%s rbd_dev %p lock_state %d ret %d - done\n", __func__,
3541                      rbd_dev, lock_state, ret);
3542                 return;
3543         }
3544
3545         ret = rbd_request_lock(rbd_dev);
3546         if (ret == -ETIMEDOUT) {
3547                 goto again; /* treat this as a dead client */
3548         } else if (ret < 0) {
3549                 rbd_warn(rbd_dev, "error requesting lock: %d", ret);
3550                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
3551                                  RBD_RETRY_DELAY);
3552         } else {
3553                 /*
3554                  * lock owner acked, but resend if we don't see them
3555                  * release the lock
3556                  */
3557                 dout("%s rbd_dev %p requeueing lock_dwork\n", __func__,
3558                      rbd_dev);
3559                 mod_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork,
3560                     msecs_to_jiffies(2 * RBD_NOTIFY_TIMEOUT * MSEC_PER_SEC));
3561         }
3562 }
3563
3564 /*
3565  * lock_rwsem must be held for write
3566  */
3567 static bool rbd_release_lock(struct rbd_device *rbd_dev)
3568 {
3569         dout("%s rbd_dev %p read lock_state %d\n", __func__, rbd_dev,
3570              rbd_dev->lock_state);
3571         if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
3572                 return false;
3573
3574         rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
3575         downgrade_write(&rbd_dev->lock_rwsem);
3576         /*
3577          * Ensure that all in-flight IO is flushed.
3578          *
3579          * FIXME: ceph_osdc_sync() flushes the entire OSD client, which
3580          * may be shared with other devices.
3581          */
3582         ceph_osdc_sync(&rbd_dev->rbd_client->client->osdc);
3583         up_read(&rbd_dev->lock_rwsem);
3584
3585         down_write(&rbd_dev->lock_rwsem);
3586         dout("%s rbd_dev %p write lock_state %d\n", __func__, rbd_dev,
3587              rbd_dev->lock_state);
3588         if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
3589                 return false;
3590
3591         if (!rbd_unlock(rbd_dev))
3592                 /*
3593                  * Give others a chance to grab the lock - we would re-acquire
3594                  * almost immediately if we got new IO during ceph_osdc_sync()
3595                  * otherwise.  We need to ack our own notifications, so this
3596                  * lock_dwork will be requeued from rbd_wait_state_locked()
3597                  * after wake_requests() in rbd_handle_released_lock().
3598                  */
3599                 cancel_delayed_work(&rbd_dev->lock_dwork);
3600
3601         return true;
3602 }
3603
3604 static void rbd_release_lock_work(struct work_struct *work)
3605 {
3606         struct rbd_device *rbd_dev = container_of(work, struct rbd_device,
3607                                                   unlock_work);
3608
3609         down_write(&rbd_dev->lock_rwsem);
3610         rbd_release_lock(rbd_dev);
3611         up_write(&rbd_dev->lock_rwsem);
3612 }
3613
3614 static void rbd_handle_acquired_lock(struct rbd_device *rbd_dev, u8 struct_v,
3615                                      void **p)
3616 {
3617         struct rbd_client_id cid = { 0 };
3618
3619         if (struct_v >= 2) {
3620                 cid.gid = ceph_decode_64(p);
3621                 cid.handle = ceph_decode_64(p);
3622         }
3623
3624         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
3625              cid.handle);
3626         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
3627                 down_write(&rbd_dev->lock_rwsem);
3628                 if (rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
3629                         /*
3630                          * we already know that the remote client is
3631                          * the owner
3632                          */
3633                         up_write(&rbd_dev->lock_rwsem);
3634                         return;
3635                 }
3636
3637                 rbd_set_owner_cid(rbd_dev, &cid);
3638                 downgrade_write(&rbd_dev->lock_rwsem);
3639         } else {
3640                 down_read(&rbd_dev->lock_rwsem);
3641         }
3642
3643         if (!__rbd_is_lock_owner(rbd_dev))
3644                 wake_requests(rbd_dev, false);
3645         up_read(&rbd_dev->lock_rwsem);
3646 }
3647
3648 static void rbd_handle_released_lock(struct rbd_device *rbd_dev, u8 struct_v,
3649                                      void **p)
3650 {
3651         struct rbd_client_id cid = { 0 };
3652
3653         if (struct_v >= 2) {
3654                 cid.gid = ceph_decode_64(p);
3655                 cid.handle = ceph_decode_64(p);
3656         }
3657
3658         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
3659              cid.handle);
3660         if (!rbd_cid_equal(&cid, &rbd_empty_cid)) {
3661                 down_write(&rbd_dev->lock_rwsem);
3662                 if (!rbd_cid_equal(&cid, &rbd_dev->owner_cid)) {
3663                         dout("%s rbd_dev %p unexpected owner, cid %llu-%llu != owner_cid %llu-%llu\n",
3664                              __func__, rbd_dev, cid.gid, cid.handle,
3665                              rbd_dev->owner_cid.gid, rbd_dev->owner_cid.handle);
3666                         up_write(&rbd_dev->lock_rwsem);
3667                         return;
3668                 }
3669
3670                 rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
3671                 downgrade_write(&rbd_dev->lock_rwsem);
3672         } else {
3673                 down_read(&rbd_dev->lock_rwsem);
3674         }
3675
3676         if (!__rbd_is_lock_owner(rbd_dev))
3677                 wake_requests(rbd_dev, false);
3678         up_read(&rbd_dev->lock_rwsem);
3679 }
3680
3681 static bool rbd_handle_request_lock(struct rbd_device *rbd_dev, u8 struct_v,
3682                                     void **p)
3683 {
3684         struct rbd_client_id my_cid = rbd_get_cid(rbd_dev);
3685         struct rbd_client_id cid = { 0 };
3686         bool need_to_send;
3687
3688         if (struct_v >= 2) {
3689                 cid.gid = ceph_decode_64(p);
3690                 cid.handle = ceph_decode_64(p);
3691         }
3692
3693         dout("%s rbd_dev %p cid %llu-%llu\n", __func__, rbd_dev, cid.gid,
3694              cid.handle);
3695         if (rbd_cid_equal(&cid, &my_cid))
3696                 return false;
3697
3698         down_read(&rbd_dev->lock_rwsem);
3699         need_to_send = __rbd_is_lock_owner(rbd_dev);
3700         if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) {
3701                 if (!rbd_cid_equal(&rbd_dev->owner_cid, &rbd_empty_cid)) {
3702                         dout("%s rbd_dev %p queueing unlock_work\n", __func__,
3703                              rbd_dev);
3704                         queue_work(rbd_dev->task_wq, &rbd_dev->unlock_work);
3705                 }
3706         }
3707         up_read(&rbd_dev->lock_rwsem);
3708         return need_to_send;
3709 }
3710
3711 static void __rbd_acknowledge_notify(struct rbd_device *rbd_dev,
3712                                      u64 notify_id, u64 cookie, s32 *result)
3713 {
3714         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3715         int buf_size = 4 + CEPH_ENCODING_START_BLK_LEN;
3716         char buf[buf_size];
3717         int ret;
3718
3719         if (result) {
3720                 void *p = buf;
3721
3722                 /* encode ResponseMessage */
3723                 ceph_start_encoding(&p, 1, 1,
3724                                     buf_size - CEPH_ENCODING_START_BLK_LEN);
3725                 ceph_encode_32(&p, *result);
3726         } else {
3727                 buf_size = 0;
3728         }
3729
3730         ret = ceph_osdc_notify_ack(osdc, &rbd_dev->header_oid,
3731                                    &rbd_dev->header_oloc, notify_id, cookie,
3732                                    buf, buf_size);
3733         if (ret)
3734                 rbd_warn(rbd_dev, "acknowledge_notify failed: %d", ret);
3735 }
3736
3737 static void rbd_acknowledge_notify(struct rbd_device *rbd_dev, u64 notify_id,
3738                                    u64 cookie)
3739 {
3740         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3741         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, NULL);
3742 }
3743
3744 static void rbd_acknowledge_notify_result(struct rbd_device *rbd_dev,
3745                                           u64 notify_id, u64 cookie, s32 result)
3746 {
3747         dout("%s rbd_dev %p result %d\n", __func__, rbd_dev, result);
3748         __rbd_acknowledge_notify(rbd_dev, notify_id, cookie, &result);
3749 }
3750
3751 static void rbd_watch_cb(void *arg, u64 notify_id, u64 cookie,
3752                          u64 notifier_id, void *data, size_t data_len)
3753 {
3754         struct rbd_device *rbd_dev = arg;
3755         void *p = data;
3756         void *const end = p + data_len;
3757         u8 struct_v;
3758         u32 len;
3759         u32 notify_op;
3760         int ret;
3761
3762         dout("%s rbd_dev %p cookie %llu notify_id %llu data_len %zu\n",
3763              __func__, rbd_dev, cookie, notify_id, data_len);
3764         if (data_len) {
3765                 ret = ceph_start_decoding(&p, end, 1, "NotifyMessage",
3766                                           &struct_v, &len);
3767                 if (ret) {
3768                         rbd_warn(rbd_dev, "failed to decode NotifyMessage: %d",
3769                                  ret);
3770                         return;
3771                 }
3772
3773                 notify_op = ceph_decode_32(&p);
3774         } else {
3775                 /* legacy notification for header updates */
3776                 notify_op = RBD_NOTIFY_OP_HEADER_UPDATE;
3777                 len = 0;
3778         }
3779
3780         dout("%s rbd_dev %p notify_op %u\n", __func__, rbd_dev, notify_op);
3781         switch (notify_op) {
3782         case RBD_NOTIFY_OP_ACQUIRED_LOCK:
3783                 rbd_handle_acquired_lock(rbd_dev, struct_v, &p);
3784                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3785                 break;
3786         case RBD_NOTIFY_OP_RELEASED_LOCK:
3787                 rbd_handle_released_lock(rbd_dev, struct_v, &p);
3788                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3789                 break;
3790         case RBD_NOTIFY_OP_REQUEST_LOCK:
3791                 if (rbd_handle_request_lock(rbd_dev, struct_v, &p))
3792                         /*
3793                          * send ResponseMessage(0) back so the client
3794                          * can detect a missing owner
3795                          */
3796                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
3797                                                       cookie, 0);
3798                 else
3799                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3800                 break;
3801         case RBD_NOTIFY_OP_HEADER_UPDATE:
3802                 ret = rbd_dev_refresh(rbd_dev);
3803                 if (ret)
3804                         rbd_warn(rbd_dev, "refresh failed: %d", ret);
3805
3806                 rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3807                 break;
3808         default:
3809                 if (rbd_is_lock_owner(rbd_dev))
3810                         rbd_acknowledge_notify_result(rbd_dev, notify_id,
3811                                                       cookie, -EOPNOTSUPP);
3812                 else
3813                         rbd_acknowledge_notify(rbd_dev, notify_id, cookie);
3814                 break;
3815         }
3816 }
3817
3818 static void __rbd_unregister_watch(struct rbd_device *rbd_dev);
3819
3820 static void rbd_watch_errcb(void *arg, u64 cookie, int err)
3821 {
3822         struct rbd_device *rbd_dev = arg;
3823
3824         rbd_warn(rbd_dev, "encountered watch error: %d", err);
3825
3826         down_write(&rbd_dev->lock_rwsem);
3827         rbd_set_owner_cid(rbd_dev, &rbd_empty_cid);
3828         up_write(&rbd_dev->lock_rwsem);
3829
3830         mutex_lock(&rbd_dev->watch_mutex);
3831         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED) {
3832                 __rbd_unregister_watch(rbd_dev);
3833                 rbd_dev->watch_state = RBD_WATCH_STATE_ERROR;
3834
3835                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->watch_dwork, 0);
3836         }
3837         mutex_unlock(&rbd_dev->watch_mutex);
3838 }
3839
3840 /*
3841  * watch_mutex must be locked
3842  */
3843 static int __rbd_register_watch(struct rbd_device *rbd_dev)
3844 {
3845         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3846         struct ceph_osd_linger_request *handle;
3847
3848         rbd_assert(!rbd_dev->watch_handle);
3849         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3850
3851         handle = ceph_osdc_watch(osdc, &rbd_dev->header_oid,
3852                                  &rbd_dev->header_oloc, rbd_watch_cb,
3853                                  rbd_watch_errcb, rbd_dev);
3854         if (IS_ERR(handle))
3855                 return PTR_ERR(handle);
3856
3857         rbd_dev->watch_handle = handle;
3858         return 0;
3859 }
3860
3861 /*
3862  * watch_mutex must be locked
3863  */
3864 static void __rbd_unregister_watch(struct rbd_device *rbd_dev)
3865 {
3866         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
3867         int ret;
3868
3869         rbd_assert(rbd_dev->watch_handle);
3870         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3871
3872         ret = ceph_osdc_unwatch(osdc, rbd_dev->watch_handle);
3873         if (ret)
3874                 rbd_warn(rbd_dev, "failed to unwatch: %d", ret);
3875
3876         rbd_dev->watch_handle = NULL;
3877 }
3878
3879 static int rbd_register_watch(struct rbd_device *rbd_dev)
3880 {
3881         int ret;
3882
3883         mutex_lock(&rbd_dev->watch_mutex);
3884         rbd_assert(rbd_dev->watch_state == RBD_WATCH_STATE_UNREGISTERED);
3885         ret = __rbd_register_watch(rbd_dev);
3886         if (ret)
3887                 goto out;
3888
3889         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
3890         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
3891
3892 out:
3893         mutex_unlock(&rbd_dev->watch_mutex);
3894         return ret;
3895 }
3896
3897 static void cancel_tasks_sync(struct rbd_device *rbd_dev)
3898 {
3899         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3900
3901         cancel_delayed_work_sync(&rbd_dev->watch_dwork);
3902         cancel_work_sync(&rbd_dev->acquired_lock_work);
3903         cancel_work_sync(&rbd_dev->released_lock_work);
3904         cancel_delayed_work_sync(&rbd_dev->lock_dwork);
3905         cancel_work_sync(&rbd_dev->unlock_work);
3906 }
3907
3908 static void rbd_unregister_watch(struct rbd_device *rbd_dev)
3909 {
3910         WARN_ON(waitqueue_active(&rbd_dev->lock_waitq));
3911         cancel_tasks_sync(rbd_dev);
3912
3913         mutex_lock(&rbd_dev->watch_mutex);
3914         if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED)
3915                 __rbd_unregister_watch(rbd_dev);
3916         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
3917         mutex_unlock(&rbd_dev->watch_mutex);
3918
3919         ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
3920 }
3921
3922 static void rbd_reregister_watch(struct work_struct *work)
3923 {
3924         struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
3925                                             struct rbd_device, watch_dwork);
3926         bool was_lock_owner = false;
3927         int ret;
3928
3929         dout("%s rbd_dev %p\n", __func__, rbd_dev);
3930
3931         down_write(&rbd_dev->lock_rwsem);
3932         if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)
3933                 was_lock_owner = rbd_release_lock(rbd_dev);
3934
3935         mutex_lock(&rbd_dev->watch_mutex);
3936         if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR)
3937                 goto fail_unlock;
3938
3939         ret = __rbd_register_watch(rbd_dev);
3940         if (ret) {
3941                 rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
3942                 if (ret != -EBLACKLISTED)
3943                         queue_delayed_work(rbd_dev->task_wq,
3944                                            &rbd_dev->watch_dwork,
3945                                            RBD_RETRY_DELAY);
3946                 goto fail_unlock;
3947         }
3948
3949         rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
3950         rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
3951         mutex_unlock(&rbd_dev->watch_mutex);
3952
3953         ret = rbd_dev_refresh(rbd_dev);
3954         if (ret)
3955                 rbd_warn(rbd_dev, "reregisteration refresh failed: %d", ret);
3956
3957         if (was_lock_owner) {
3958                 ret = rbd_try_lock(rbd_dev);
3959                 if (ret)
3960                         rbd_warn(rbd_dev, "reregisteration lock failed: %d",
3961                                  ret);
3962         }
3963
3964         up_write(&rbd_dev->lock_rwsem);
3965         wake_requests(rbd_dev, true);
3966         return;
3967
3968 fail_unlock:
3969         mutex_unlock(&rbd_dev->watch_mutex);
3970         up_write(&rbd_dev->lock_rwsem);
3971 }
3972
3973 /*
3974  * Synchronous osd object method call.  Returns the number of bytes
3975  * returned in the outbound buffer, or a negative error code.
3976  */
3977 static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
3978                              const char *object_name,
3979                              const char *class_name,
3980                              const char *method_name,
3981                              const void *outbound,
3982                              size_t outbound_size,
3983                              void *inbound,
3984                              size_t inbound_size)
3985 {
3986         struct rbd_obj_request *obj_request;
3987         struct page **pages;
3988         u32 page_count;
3989         int ret;
3990
3991         /*
3992          * Method calls are ultimately read operations.  The result
3993          * should placed into the inbound buffer provided.  They
3994          * also supply outbound data--parameters for the object
3995          * method.  Currently if this is present it will be a
3996          * snapshot id.
3997          */
3998         page_count = (u32)calc_pages_for(0, inbound_size);
3999         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
4000         if (IS_ERR(pages))
4001                 return PTR_ERR(pages);
4002
4003         ret = -ENOMEM;
4004         obj_request = rbd_obj_request_create(object_name, 0, inbound_size,
4005                                                         OBJ_REQUEST_PAGES);
4006         if (!obj_request)
4007                 goto out;
4008
4009         obj_request->pages = pages;
4010         obj_request->page_count = page_count;
4011
4012         obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4013                                                   obj_request);
4014         if (!obj_request->osd_req)
4015                 goto out;
4016
4017         osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
4018                                         class_name, method_name);
4019         if (outbound_size) {
4020                 struct ceph_pagelist *pagelist;
4021
4022                 pagelist = kmalloc(sizeof (*pagelist), GFP_NOFS);
4023                 if (!pagelist)
4024                         goto out;
4025
4026                 ceph_pagelist_init(pagelist);
4027                 ceph_pagelist_append(pagelist, outbound, outbound_size);
4028                 osd_req_op_cls_request_data_pagelist(obj_request->osd_req, 0,
4029                                                 pagelist);
4030         }
4031         osd_req_op_cls_response_data_pages(obj_request->osd_req, 0,
4032                                         obj_request->pages, inbound_size,
4033                                         0, false, false);
4034
4035         rbd_obj_request_submit(obj_request);
4036         ret = rbd_obj_request_wait(obj_request);
4037         if (ret)
4038                 goto out;
4039
4040         ret = obj_request->result;
4041         if (ret < 0)
4042                 goto out;
4043
4044         rbd_assert(obj_request->xferred < (u64)INT_MAX);
4045         ret = (int)obj_request->xferred;
4046         ceph_copy_from_page_vector(pages, inbound, 0, obj_request->xferred);
4047 out:
4048         if (obj_request)
4049                 rbd_obj_request_put(obj_request);
4050         else
4051                 ceph_release_page_vector(pages, page_count);
4052
4053         return ret;
4054 }
4055
4056 /*
4057  * lock_rwsem must be held for read
4058  */
4059 static void rbd_wait_state_locked(struct rbd_device *rbd_dev)
4060 {
4061         DEFINE_WAIT(wait);
4062
4063         do {
4064                 /*
4065                  * Note the use of mod_delayed_work() in rbd_acquire_lock()
4066                  * and cancel_delayed_work() in wake_requests().
4067                  */
4068                 dout("%s rbd_dev %p queueing lock_dwork\n", __func__, rbd_dev);
4069                 queue_delayed_work(rbd_dev->task_wq, &rbd_dev->lock_dwork, 0);
4070                 prepare_to_wait_exclusive(&rbd_dev->lock_waitq, &wait,
4071                                           TASK_UNINTERRUPTIBLE);
4072                 up_read(&rbd_dev->lock_rwsem);
4073                 schedule();
4074                 down_read(&rbd_dev->lock_rwsem);
4075         } while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);
4076         finish_wait(&rbd_dev->lock_waitq, &wait);
4077 }
4078
4079 static void rbd_queue_workfn(struct work_struct *work)
4080 {
4081         struct request *rq = blk_mq_rq_from_pdu(work);
4082         struct rbd_device *rbd_dev = rq->q->queuedata;
4083         struct rbd_img_request *img_request;
4084         struct ceph_snap_context *snapc = NULL;
4085         u64 offset = (u64)blk_rq_pos(rq) << SECTOR_SHIFT;
4086         u64 length = blk_rq_bytes(rq);
4087         enum obj_operation_type op_type;
4088         u64 mapping_size;
4089         bool must_be_locked;
4090         int result;
4091
4092         if (rq->cmd_type != REQ_TYPE_FS) {
4093                 dout("%s: non-fs request type %d\n", __func__,
4094                         (int) rq->cmd_type);
4095                 result = -EIO;
4096                 goto err;
4097         }
4098
4099         if (req_op(rq) == REQ_OP_DISCARD)
4100                 op_type = OBJ_OP_DISCARD;
4101         else if (req_op(rq) == REQ_OP_WRITE)
4102                 op_type = OBJ_OP_WRITE;
4103         else
4104                 op_type = OBJ_OP_READ;
4105
4106         /* Ignore/skip any zero-length requests */
4107
4108         if (!length) {
4109                 dout("%s: zero-length request\n", __func__);
4110                 result = 0;
4111                 goto err_rq;
4112         }
4113
4114         /* Only reads are allowed to a read-only device */
4115
4116         if (op_type != OBJ_OP_READ) {
4117                 if (rbd_dev->mapping.read_only) {
4118                         result = -EROFS;
4119                         goto err_rq;
4120                 }
4121                 rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
4122         }
4123
4124         /*
4125          * Quit early if the mapped snapshot no longer exists.  It's
4126          * still possible the snapshot will have disappeared by the
4127          * time our request arrives at the osd, but there's no sense in
4128          * sending it if we already know.
4129          */
4130         if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags)) {
4131                 dout("request for non-existent snapshot");
4132                 rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);
4133                 result = -ENXIO;
4134                 goto err_rq;
4135         }
4136
4137         if (offset && length > U64_MAX - offset + 1) {
4138                 rbd_warn(rbd_dev, "bad request range (%llu~%llu)", offset,
4139                          length);
4140                 result = -EINVAL;
4141                 goto err_rq;    /* Shouldn't happen */
4142         }
4143
4144         blk_mq_start_request(rq);
4145
4146         down_read(&rbd_dev->header_rwsem);
4147         mapping_size = rbd_dev->mapping.size;
4148         if (op_type != OBJ_OP_READ) {
4149                 snapc = rbd_dev->header.snapc;
4150                 ceph_get_snap_context(snapc);
4151                 must_be_locked = rbd_is_lock_supported(rbd_dev);
4152         } else {
4153                 must_be_locked = rbd_dev->opts->lock_on_read &&
4154                                         rbd_is_lock_supported(rbd_dev);
4155         }
4156         up_read(&rbd_dev->header_rwsem);
4157
4158         if (offset + length > mapping_size) {
4159                 rbd_warn(rbd_dev, "beyond EOD (%llu~%llu > %llu)", offset,
4160                          length, mapping_size);
4161                 result = -EIO;
4162                 goto err_rq;
4163         }
4164
4165         if (must_be_locked) {
4166                 down_read(&rbd_dev->lock_rwsem);
4167                 if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
4168                         rbd_wait_state_locked(rbd_dev);
4169         }
4170
4171         img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,
4172                                              snapc);
4173         if (!img_request) {
4174                 result = -ENOMEM;
4175                 goto err_unlock;
4176         }
4177         img_request->rq = rq;
4178         snapc = NULL; /* img_request consumes a ref */
4179
4180         if (op_type == OBJ_OP_DISCARD)
4181                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_NODATA,
4182                                               NULL);
4183         else
4184                 result = rbd_img_request_fill(img_request, OBJ_REQUEST_BIO,
4185                                               rq->bio);
4186         if (result)
4187                 goto err_img_request;
4188
4189         result = rbd_img_request_submit(img_request);
4190         if (result)
4191                 goto err_img_request;
4192
4193         if (must_be_locked)
4194                 up_read(&rbd_dev->lock_rwsem);
4195         return;
4196
4197 err_img_request:
4198         rbd_img_request_put(img_request);
4199 err_unlock:
4200         if (must_be_locked)
4201                 up_read(&rbd_dev->lock_rwsem);
4202 err_rq:
4203         if (result)
4204                 rbd_warn(rbd_dev, "%s %llx at %llx result %d",
4205                          obj_op_name(op_type), length, offset, result);
4206         ceph_put_snap_context(snapc);
4207 err:
4208         blk_mq_end_request(rq, result);
4209 }
4210
4211 static int rbd_queue_rq(struct blk_mq_hw_ctx *hctx,
4212                 const struct blk_mq_queue_data *bd)
4213 {
4214         struct request *rq = bd->rq;
4215         struct work_struct *work = blk_mq_rq_to_pdu(rq);
4216
4217         queue_work(rbd_wq, work);
4218         return BLK_MQ_RQ_QUEUE_OK;
4219 }
4220
4221 static void rbd_free_disk(struct rbd_device *rbd_dev)
4222 {
4223         struct gendisk *disk = rbd_dev->disk;
4224
4225         if (!disk)
4226                 return;
4227
4228         rbd_dev->disk = NULL;
4229         if (disk->flags & GENHD_FL_UP) {
4230                 del_gendisk(disk);
4231                 if (disk->queue)
4232                         blk_cleanup_queue(disk->queue);
4233                 blk_mq_free_tag_set(&rbd_dev->tag_set);
4234         }
4235         put_disk(disk);
4236 }
4237
4238 static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
4239                                 const char *object_name,
4240                                 u64 offset, u64 length, void *buf)
4241
4242 {
4243         struct rbd_obj_request *obj_request;
4244         struct page **pages = NULL;
4245         u32 page_count;
4246         size_t size;
4247         int ret;
4248
4249         page_count = (u32) calc_pages_for(offset, length);
4250         pages = ceph_alloc_page_vector(page_count, GFP_KERNEL);
4251         if (IS_ERR(pages))
4252                 return PTR_ERR(pages);
4253
4254         ret = -ENOMEM;
4255         obj_request = rbd_obj_request_create(object_name, offset, length,
4256                                                         OBJ_REQUEST_PAGES);
4257         if (!obj_request)
4258                 goto out;
4259
4260         obj_request->pages = pages;
4261         obj_request->page_count = page_count;
4262
4263         obj_request->osd_req = rbd_osd_req_create(rbd_dev, OBJ_OP_READ, 1,
4264                                                   obj_request);
4265         if (!obj_request->osd_req)
4266                 goto out;
4267
4268         osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
4269                                         offset, length, 0, 0);
4270         osd_req_op_extent_osd_data_pages(obj_request->osd_req, 0,
4271                                         obj_request->pages,
4272                                         obj_request->length,
4273                                         obj_request->offset & ~PAGE_MASK,
4274                                         false, false);
4275
4276         rbd_obj_request_submit(obj_request);
4277         ret = rbd_obj_request_wait(obj_request);
4278         if (ret)
4279                 goto out;
4280
4281         ret = obj_request->result;
4282         if (ret < 0)
4283                 goto out;
4284
4285         rbd_assert(obj_request->xferred <= (u64) SIZE_MAX);
4286         size = (size_t) obj_request->xferred;
4287         ceph_copy_from_page_vector(pages, buf, 0, size);
4288         rbd_assert(size <= (size_t)INT_MAX);
4289         ret = (int)size;
4290 out:
4291         if (obj_request)
4292                 rbd_obj_request_put(obj_request);
4293         else
4294                 ceph_release_page_vector(pages, page_count);
4295
4296         return ret;
4297 }
4298
4299 /*
4300  * Read the complete header for the given rbd device.  On successful
4301  * return, the rbd_dev->header field will contain up-to-date
4302  * information about the image.
4303  */
4304 static int rbd_dev_v1_header_info(struct rbd_device *rbd_dev)
4305 {
4306         struct rbd_image_header_ondisk *ondisk = NULL;
4307         u32 snap_count = 0;
4308         u64 names_size = 0;
4309         u32 want_count;
4310         int ret;
4311
4312         /*
4313          * The complete header will include an array of its 64-bit
4314          * snapshot ids, followed by the names of those snapshots as
4315          * a contiguous block of NUL-terminated strings.  Note that
4316          * the number of snapshots could change by the time we read
4317          * it in, in which case we re-read it.
4318          */
4319         do {
4320                 size_t size;
4321
4322                 kfree(ondisk);
4323
4324                 size = sizeof (*ondisk);
4325                 size += snap_count * sizeof (struct rbd_image_snap_ondisk);
4326                 size += names_size;
4327                 ondisk = kmalloc(size, GFP_KERNEL);
4328                 if (!ondisk)
4329                         return -ENOMEM;
4330
4331                 ret = rbd_obj_read_sync(rbd_dev, rbd_dev->header_oid.name,
4332                                        0, size, ondisk);
4333                 if (ret < 0)
4334                         goto out;
4335                 if ((size_t)ret < size) {
4336                         ret = -ENXIO;
4337                         rbd_warn(rbd_dev, "short header read (want %zd got %d)",
4338                                 size, ret);
4339                         goto out;
4340                 }
4341                 if (!rbd_dev_ondisk_valid(ondisk)) {
4342                         ret = -ENXIO;
4343                         rbd_warn(rbd_dev, "invalid header");
4344                         goto out;
4345                 }
4346
4347                 names_size = le64_to_cpu(ondisk->snap_names_len);
4348                 want_count = snap_count;
4349                 snap_count = le32_to_cpu(ondisk->snap_count);
4350         } while (snap_count != want_count);
4351
4352         ret = rbd_header_from_disk(rbd_dev, ondisk);
4353 out:
4354         kfree(ondisk);
4355
4356         return ret;
4357 }
4358
4359 /*
4360  * Clear the rbd device's EXISTS flag if the snapshot it's mapped to
4361  * has disappeared from the (just updated) snapshot context.
4362  */
4363 static void rbd_exists_validate(struct rbd_device *rbd_dev)
4364 {
4365         u64 snap_id;
4366
4367         if (!test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags))
4368                 return;
4369
4370         snap_id = rbd_dev->spec->snap_id;
4371         if (snap_id == CEPH_NOSNAP)
4372                 return;
4373
4374         if (rbd_dev_snap_index(rbd_dev, snap_id) == BAD_SNAP_INDEX)
4375                 clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
4376 }
4377
4378 static void rbd_dev_update_size(struct rbd_device *rbd_dev)
4379 {
4380         sector_t size;
4381
4382         /*
4383          * If EXISTS is not set, rbd_dev->disk may be NULL, so don't
4384          * try to update its size.  If REMOVING is set, updating size
4385          * is just useless work since the device can't be opened.
4386          */
4387         if (test_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags) &&
4388             !test_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags)) {
4389                 size = (sector_t)rbd_dev->mapping.size / SECTOR_SIZE;
4390                 dout("setting size to %llu sectors", (unsigned long long)size);
4391                 set_capacity(rbd_dev->disk, size);
4392                 revalidate_disk(rbd_dev->disk);
4393         }
4394 }
4395
4396 static int rbd_dev_refresh(struct rbd_device *rbd_dev)
4397 {
4398         u64 mapping_size;
4399         int ret;
4400
4401         down_write(&rbd_dev->header_rwsem);
4402         mapping_size = rbd_dev->mapping.size;
4403
4404         ret = rbd_dev_header_info(rbd_dev);
4405         if (ret)
4406                 goto out;
4407
4408         /*
4409          * If there is a parent, see if it has disappeared due to the
4410          * mapped image getting flattened.
4411          */
4412         if (rbd_dev->parent) {
4413                 ret = rbd_dev_v2_parent_info(rbd_dev);
4414                 if (ret)
4415                         goto out;
4416         }
4417
4418         if (rbd_dev->spec->snap_id == CEPH_NOSNAP) {
4419                 rbd_dev->mapping.size = rbd_dev->header.image_size;
4420         } else {
4421                 /* validate mapped snapshot's EXISTS flag */
4422                 rbd_exists_validate(rbd_dev);
4423         }
4424
4425 out:
4426         up_write(&rbd_dev->header_rwsem);
4427         if (!ret && mapping_size != rbd_dev->mapping.size)
4428                 rbd_dev_update_size(rbd_dev);
4429
4430         return ret;
4431 }
4432
4433 static int rbd_init_request(void *data, struct request *rq,
4434                 unsigned int hctx_idx, unsigned int request_idx,
4435                 unsigned int numa_node)
4436 {
4437         struct work_struct *work = blk_mq_rq_to_pdu(rq);
4438
4439         INIT_WORK(work, rbd_queue_workfn);
4440         return 0;
4441 }
4442
4443 static struct blk_mq_ops rbd_mq_ops = {
4444         .queue_rq       = rbd_queue_rq,
4445         .map_queue      = blk_mq_map_queue,
4446         .init_request   = rbd_init_request,
4447 };
4448
4449 static int rbd_init_disk(struct rbd_device *rbd_dev)
4450 {
4451         struct gendisk *disk;
4452         struct request_queue *q;
4453         u64 segment_size;
4454         int err;
4455
4456         /* create gendisk info */
4457         disk = alloc_disk(single_major ?
4458                           (1 << RBD_SINGLE_MAJOR_PART_SHIFT) :
4459                           RBD_MINORS_PER_MAJOR);
4460         if (!disk)
4461                 return -ENOMEM;
4462
4463         snprintf(disk->disk_name, sizeof(disk->disk_name), RBD_DRV_NAME "%d",
4464                  rbd_dev->dev_id);
4465         disk->major = rbd_dev->major;
4466         disk->first_minor = rbd_dev->minor;
4467         if (single_major)
4468                 disk->flags |= GENHD_FL_EXT_DEVT;
4469         disk->fops = &rbd_bd_ops;
4470         disk->private_data = rbd_dev;
4471
4472         memset(&rbd_dev->tag_set, 0, sizeof(rbd_dev->tag_set));
4473         rbd_dev->tag_set.ops = &rbd_mq_ops;
4474         rbd_dev->tag_set.queue_depth = rbd_dev->opts->queue_depth;
4475         rbd_dev->tag_set.numa_node = NUMA_NO_NODE;
4476         rbd_dev->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
4477         rbd_dev->tag_set.nr_hw_queues = 1;
4478         rbd_dev->tag_set.cmd_size = sizeof(struct work_struct);
4479
4480         err = blk_mq_alloc_tag_set(&rbd_dev->tag_set);
4481         if (err)
4482                 goto out_disk;
4483
4484         q = blk_mq_init_queue(&rbd_dev->tag_set);
4485         if (IS_ERR(q)) {
4486                 err = PTR_ERR(q);
4487                 goto out_tag_set;
4488         }
4489
4490         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
4491         /* QUEUE_FLAG_ADD_RANDOM is off by default for blk-mq */
4492
4493         /* set io sizes to object size */
4494         segment_size = rbd_obj_bytes(&rbd_dev->header);
4495         blk_queue_max_hw_sectors(q, segment_size / SECTOR_SIZE);
4496         q->limits.max_sectors = queue_max_hw_sectors(q);
4497         blk_queue_max_segments(q, segment_size / SECTOR_SIZE);
4498         blk_queue_max_segment_size(q, segment_size);
4499         blk_queue_io_min(q, segment_size);
4500         blk_queue_io_opt(q, segment_size);
4501
4502         /* enable the discard support */
4503         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
4504         q->limits.discard_granularity = segment_size;
4505         q->limits.discard_alignment = segment_size;
4506         blk_queue_max_discard_sectors(q, segment_size / SECTOR_SIZE);
4507         q->limits.discard_zeroes_data = 1;
4508
4509         if (!ceph_test_opt(rbd_dev->rbd_client->client, NOCRC))
4510                 q->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;
4511
4512         disk->queue = q;
4513
4514         q->queuedata = rbd_dev;
4515
4516         rbd_dev->disk = disk;
4517
4518         return 0;
4519 out_tag_set:
4520         blk_mq_free_tag_set(&rbd_dev->tag_set);
4521 out_disk:
4522         put_disk(disk);
4523         return err;
4524 }
4525
4526 /*
4527   sysfs
4528 */
4529
4530 static struct rbd_device *dev_to_rbd_dev(struct device *dev)
4531 {
4532         return container_of(dev, struct rbd_device, dev);
4533 }
4534
4535 static ssize_t rbd_size_show(struct device *dev,
4536                              struct device_attribute *attr, char *buf)
4537 {
4538         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4539
4540         return sprintf(buf, "%llu\n",
4541                 (unsigned long long)rbd_dev->mapping.size);
4542 }
4543
4544 /*
4545  * Note this shows the features for whatever's mapped, which is not
4546  * necessarily the base image.
4547  */
4548 static ssize_t rbd_features_show(struct device *dev,
4549                              struct device_attribute *attr, char *buf)
4550 {
4551         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4552
4553         return sprintf(buf, "0x%016llx\n",
4554                         (unsigned long long)rbd_dev->mapping.features);
4555 }
4556
4557 static ssize_t rbd_major_show(struct device *dev,
4558                               struct device_attribute *attr, char *buf)
4559 {
4560         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4561
4562         if (rbd_dev->major)
4563                 return sprintf(buf, "%d\n", rbd_dev->major);
4564
4565         return sprintf(buf, "(none)\n");
4566 }
4567
4568 static ssize_t rbd_minor_show(struct device *dev,
4569                               struct device_attribute *attr, char *buf)
4570 {
4571         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4572
4573         return sprintf(buf, "%d\n", rbd_dev->minor);
4574 }
4575
4576 static ssize_t rbd_client_addr_show(struct device *dev,
4577                                     struct device_attribute *attr, char *buf)
4578 {
4579         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4580         struct ceph_entity_addr *client_addr =
4581             ceph_client_addr(rbd_dev->rbd_client->client);
4582
4583         return sprintf(buf, "%pISpc/%u\n", &client_addr->in_addr,
4584                        le32_to_cpu(client_addr->nonce));
4585 }
4586
4587 static ssize_t rbd_client_id_show(struct device *dev,
4588                                   struct device_attribute *attr, char *buf)
4589 {
4590         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4591
4592         return sprintf(buf, "client%lld\n",
4593                        ceph_client_gid(rbd_dev->rbd_client->client));
4594 }
4595
4596 static ssize_t rbd_cluster_fsid_show(struct device *dev,
4597                                      struct device_attribute *attr, char *buf)
4598 {
4599         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4600
4601         return sprintf(buf, "%pU\n", &rbd_dev->rbd_client->client->fsid);
4602 }
4603
4604 static ssize_t rbd_config_info_show(struct device *dev,
4605                                     struct device_attribute *attr, char *buf)
4606 {
4607         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4608
4609         return sprintf(buf, "%s\n", rbd_dev->config_info);
4610 }
4611
4612 static ssize_t rbd_pool_show(struct device *dev,
4613                              struct device_attribute *attr, char *buf)
4614 {
4615         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4616
4617         return sprintf(buf, "%s\n", rbd_dev->spec->pool_name);
4618 }
4619
4620 static ssize_t rbd_pool_id_show(struct device *dev,
4621                              struct device_attribute *attr, char *buf)
4622 {
4623         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4624
4625         return sprintf(buf, "%llu\n",
4626                         (unsigned long long) rbd_dev->spec->pool_id);
4627 }
4628
4629 static ssize_t rbd_name_show(struct device *dev,
4630                              struct device_attribute *attr, char *buf)
4631 {
4632         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4633
4634         if (rbd_dev->spec->image_name)
4635                 return sprintf(buf, "%s\n", rbd_dev->spec->image_name);
4636
4637         return sprintf(buf, "(unknown)\n");
4638 }
4639
4640 static ssize_t rbd_image_id_show(struct device *dev,
4641                              struct device_attribute *attr, char *buf)
4642 {
4643         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4644
4645         return sprintf(buf, "%s\n", rbd_dev->spec->image_id);
4646 }
4647
4648 /*
4649  * Shows the name of the currently-mapped snapshot (or
4650  * RBD_SNAP_HEAD_NAME for the base image).
4651  */
4652 static ssize_t rbd_snap_show(struct device *dev,
4653                              struct device_attribute *attr,
4654                              char *buf)
4655 {
4656         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4657
4658         return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
4659 }
4660
4661 static ssize_t rbd_snap_id_show(struct device *dev,
4662                                 struct device_attribute *attr, char *buf)
4663 {
4664         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4665
4666         return sprintf(buf, "%llu\n", rbd_dev->spec->snap_id);
4667 }
4668
4669 /*
4670  * For a v2 image, shows the chain of parent images, separated by empty
4671  * lines.  For v1 images or if there is no parent, shows "(no parent
4672  * image)".
4673  */
4674 static ssize_t rbd_parent_show(struct device *dev,
4675                                struct device_attribute *attr,
4676                                char *buf)
4677 {
4678         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4679         ssize_t count = 0;
4680
4681         if (!rbd_dev->parent)
4682                 return sprintf(buf, "(no parent image)\n");
4683
4684         for ( ; rbd_dev->parent; rbd_dev = rbd_dev->parent) {
4685                 struct rbd_spec *spec = rbd_dev->parent_spec;
4686
4687                 count += sprintf(&buf[count], "%s"
4688                             "pool_id %llu\npool_name %s\n"
4689                             "image_id %s\nimage_name %s\n"
4690                             "snap_id %llu\nsnap_name %s\n"
4691                             "overlap %llu\n",
4692                             !count ? "" : "\n", /* first? */
4693                             spec->pool_id, spec->pool_name,
4694                             spec->image_id, spec->image_name ?: "(unknown)",
4695                             spec->snap_id, spec->snap_name,
4696                             rbd_dev->parent_overlap);
4697         }
4698
4699         return count;
4700 }
4701
4702 static ssize_t rbd_image_refresh(struct device *dev,
4703                                  struct device_attribute *attr,
4704                                  const char *buf,
4705                                  size_t size)
4706 {
4707         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4708         int ret;
4709
4710         ret = rbd_dev_refresh(rbd_dev);
4711         if (ret)
4712                 return ret;
4713
4714         return size;
4715 }
4716
4717 static DEVICE_ATTR(size, S_IRUGO, rbd_size_show, NULL);
4718 static DEVICE_ATTR(features, S_IRUGO, rbd_features_show, NULL);
4719 static DEVICE_ATTR(major, S_IRUGO, rbd_major_show, NULL);
4720 static DEVICE_ATTR(minor, S_IRUGO, rbd_minor_show, NULL);
4721 static DEVICE_ATTR(client_addr, S_IRUGO, rbd_client_addr_show, NULL);
4722 static DEVICE_ATTR(client_id, S_IRUGO, rbd_client_id_show, NULL);
4723 static DEVICE_ATTR(cluster_fsid, S_IRUGO, rbd_cluster_fsid_show, NULL);
4724 static DEVICE_ATTR(config_info, S_IRUSR, rbd_config_info_show, NULL);
4725 static DEVICE_ATTR(pool, S_IRUGO, rbd_pool_show, NULL);
4726 static DEVICE_ATTR(pool_id, S_IRUGO, rbd_pool_id_show, NULL);
4727 static DEVICE_ATTR(name, S_IRUGO, rbd_name_show, NULL);
4728 static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
4729 static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
4730 static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
4731 static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
4732 static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
4733
4734 static struct attribute *rbd_attrs[] = {
4735         &dev_attr_size.attr,
4736         &dev_attr_features.attr,
4737         &dev_attr_major.attr,
4738         &dev_attr_minor.attr,
4739         &dev_attr_client_addr.attr,
4740         &dev_attr_client_id.attr,
4741         &dev_attr_cluster_fsid.attr,
4742         &dev_attr_config_info.attr,
4743         &dev_attr_pool.attr,
4744         &dev_attr_pool_id.attr,
4745         &dev_attr_name.attr,
4746         &dev_attr_image_id.attr,
4747         &dev_attr_current_snap.attr,
4748         &dev_attr_snap_id.attr,
4749         &dev_attr_parent.attr,
4750         &dev_attr_refresh.attr,
4751         NULL
4752 };
4753
4754 static struct attribute_group rbd_attr_group = {
4755         .attrs = rbd_attrs,
4756 };
4757
4758 static const struct attribute_group *rbd_attr_groups[] = {
4759         &rbd_attr_group,
4760         NULL
4761 };
4762
4763 static void rbd_dev_release(struct device *dev);
4764
4765 static struct device_type rbd_device_type = {
4766         .name           = "rbd",
4767         .groups         = rbd_attr_groups,
4768         .release        = rbd_dev_release,
4769 };
4770
4771 static struct rbd_spec *rbd_spec_get(struct rbd_spec *spec)
4772 {
4773         kref_get(&spec->kref);
4774
4775         return spec;
4776 }
4777
4778 static void rbd_spec_free(struct kref *kref);
4779 static void rbd_spec_put(struct rbd_spec *spec)
4780 {
4781         if (spec)
4782                 kref_put(&spec->kref, rbd_spec_free);
4783 }
4784
4785 static struct rbd_spec *rbd_spec_alloc(void)
4786 {
4787         struct rbd_spec *spec;
4788
4789         spec = kzalloc(sizeof (*spec), GFP_KERNEL);
4790         if (!spec)
4791                 return NULL;
4792
4793         spec->pool_id = CEPH_NOPOOL;
4794         spec->snap_id = CEPH_NOSNAP;
4795         kref_init(&spec->kref);
4796
4797         return spec;
4798 }
4799
4800 static void rbd_spec_free(struct kref *kref)
4801 {
4802         struct rbd_spec *spec = container_of(kref, struct rbd_spec, kref);
4803
4804         kfree(spec->pool_name);
4805         kfree(spec->image_id);
4806         kfree(spec->image_name);
4807         kfree(spec->snap_name);
4808         kfree(spec);
4809 }
4810
4811 static void rbd_dev_free(struct rbd_device *rbd_dev)
4812 {
4813         WARN_ON(rbd_dev->watch_state != RBD_WATCH_STATE_UNREGISTERED);
4814         WARN_ON(rbd_dev->lock_state != RBD_LOCK_STATE_UNLOCKED);
4815
4816         ceph_oid_destroy(&rbd_dev->header_oid);
4817         ceph_oloc_destroy(&rbd_dev->header_oloc);
4818         kfree(rbd_dev->config_info);
4819
4820         rbd_put_client(rbd_dev->rbd_client);
4821         rbd_spec_put(rbd_dev->spec);
4822         kfree(rbd_dev->opts);
4823         kfree(rbd_dev);
4824 }
4825
4826 static void rbd_dev_release(struct device *dev)
4827 {
4828         struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
4829         bool need_put = !!rbd_dev->opts;
4830
4831         if (need_put) {
4832                 destroy_workqueue(rbd_dev->task_wq);
4833                 ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
4834         }
4835
4836         rbd_dev_free(rbd_dev);
4837
4838         /*
4839          * This is racy, but way better than putting module outside of
4840          * the release callback.  The race window is pretty small, so
4841          * doing something similar to dm (dm-builtin.c) is overkill.
4842          */
4843         if (need_put)
4844                 module_put(THIS_MODULE);
4845 }
4846
4847 static struct rbd_device *__rbd_dev_create(struct rbd_client *rbdc,
4848                                            struct rbd_spec *spec)
4849 {
4850         struct rbd_device *rbd_dev;
4851
4852         rbd_dev = kzalloc(sizeof(*rbd_dev), GFP_KERNEL);
4853         if (!rbd_dev)
4854                 return NULL;
4855
4856         spin_lock_init(&rbd_dev->lock);
4857         INIT_LIST_HEAD(&rbd_dev->node);
4858         init_rwsem(&rbd_dev->header_rwsem);
4859
4860         ceph_oid_init(&rbd_dev->header_oid);
4861         ceph_oloc_init(&rbd_dev->header_oloc);
4862
4863         mutex_init(&rbd_dev->watch_mutex);
4864         rbd_dev->watch_state = RBD_WATCH_STATE_UNREGISTERED;
4865         INIT_DELAYED_WORK(&rbd_dev->watch_dwork, rbd_reregister_watch);
4866
4867         init_rwsem(&rbd_dev->lock_rwsem);
4868         rbd_dev->lock_state = RBD_LOCK_STATE_UNLOCKED;
4869         INIT_WORK(&rbd_dev->acquired_lock_work, rbd_notify_acquired_lock);
4870         INIT_WORK(&rbd_dev->released_lock_work, rbd_notify_released_lock);
4871         INIT_DELAYED_WORK(&rbd_dev->lock_dwork, rbd_acquire_lock);
4872         INIT_WORK(&rbd_dev->unlock_work, rbd_release_lock_work);
4873         init_waitqueue_head(&rbd_dev->lock_waitq);
4874
4875         rbd_dev->dev.bus = &rbd_bus_type;
4876         rbd_dev->dev.type = &rbd_device_type;
4877         rbd_dev->dev.parent = &rbd_root_dev;
4878         device_initialize(&rbd_dev->dev);
4879
4880         rbd_dev->rbd_client = rbdc;
4881         rbd_dev->spec = spec;
4882
4883         rbd_dev->layout.stripe_unit = 1 << RBD_MAX_OBJ_ORDER;
4884         rbd_dev->layout.stripe_count = 1;
4885         rbd_dev->layout.object_size = 1 << RBD_MAX_OBJ_ORDER;
4886         rbd_dev->layout.pool_id = spec->pool_id;
4887         RCU_INIT_POINTER(rbd_dev->layout.pool_ns, NULL);
4888
4889         return rbd_dev;
4890 }
4891
4892 /*
4893  * Create a mapping rbd_dev.
4894  */
4895 static struct rbd_device *rbd_dev_create(struct rbd_client *rbdc,
4896                                          struct rbd_spec *spec,
4897                                          struct rbd_options *opts)
4898 {
4899         struct rbd_device *rbd_dev;
4900
4901         rbd_dev = __rbd_dev_create(rbdc, spec);
4902         if (!rbd_dev)
4903                 return NULL;
4904
4905         rbd_dev->opts = opts;
4906
4907         /* get an id and fill in device name */
4908         rbd_dev->dev_id = ida_simple_get(&rbd_dev_id_ida, 0,
4909                                          minor_to_rbd_dev_id(1 << MINORBITS),
4910                                          GFP_KERNEL);
4911         if (rbd_dev->dev_id < 0)
4912                 goto fail_rbd_dev;
4913
4914         sprintf(rbd_dev->name, RBD_DRV_NAME "%d", rbd_dev->dev_id);
4915         rbd_dev->task_wq = alloc_ordered_workqueue("%s-tasks", WQ_MEM_RECLAIM,
4916                                                    rbd_dev->name);
4917         if (!rbd_dev->task_wq)
4918                 goto fail_dev_id;
4919
4920         /* we have a ref from do_rbd_add() */
4921         __module_get(THIS_MODULE);
4922
4923         dout("%s rbd_dev %p dev_id %d\n", __func__, rbd_dev, rbd_dev->dev_id);
4924         return rbd_dev;
4925
4926 fail_dev_id:
4927         ida_simple_remove(&rbd_dev_id_ida, rbd_dev->dev_id);
4928 fail_rbd_dev:
4929         rbd_dev_free(rbd_dev);
4930         return NULL;
4931 }
4932
4933 static void rbd_dev_destroy(struct rbd_device *rbd_dev)
4934 {
4935         if (rbd_dev)
4936                 put_device(&rbd_dev->dev);
4937 }
4938
4939 /*
4940  * Get the size and object order for an image snapshot, or if
4941  * snap_id is CEPH_NOSNAP, gets this information for the base
4942  * image.
4943  */
4944 static int _rbd_dev_v2_snap_size(struct rbd_device *rbd_dev, u64 snap_id,
4945                                 u8 *order, u64 *snap_size)
4946 {
4947         __le64 snapid = cpu_to_le64(snap_id);
4948         int ret;
4949         struct {
4950                 u8 order;
4951                 __le64 size;
4952         } __attribute__ ((packed)) size_buf = { 0 };
4953
4954         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
4955                                 "rbd", "get_size",
4956                                 &snapid, sizeof (snapid),
4957                                 &size_buf, sizeof (size_buf));
4958         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4959         if (ret < 0)
4960                 return ret;
4961         if (ret < sizeof (size_buf))
4962                 return -ERANGE;
4963
4964         if (order) {
4965                 *order = size_buf.order;
4966                 dout("  order %u", (unsigned int)*order);
4967         }
4968         *snap_size = le64_to_cpu(size_buf.size);
4969
4970         dout("  snap_id 0x%016llx snap_size = %llu\n",
4971                 (unsigned long long)snap_id,
4972                 (unsigned long long)*snap_size);
4973
4974         return 0;
4975 }
4976
4977 static int rbd_dev_v2_image_size(struct rbd_device *rbd_dev)
4978 {
4979         return _rbd_dev_v2_snap_size(rbd_dev, CEPH_NOSNAP,
4980                                         &rbd_dev->header.obj_order,
4981                                         &rbd_dev->header.image_size);
4982 }
4983
4984 static int rbd_dev_v2_object_prefix(struct rbd_device *rbd_dev)
4985 {
4986         void *reply_buf;
4987         int ret;
4988         void *p;
4989
4990         reply_buf = kzalloc(RBD_OBJ_PREFIX_LEN_MAX, GFP_KERNEL);
4991         if (!reply_buf)
4992                 return -ENOMEM;
4993
4994         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
4995                                 "rbd", "get_object_prefix", NULL, 0,
4996                                 reply_buf, RBD_OBJ_PREFIX_LEN_MAX);
4997         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
4998         if (ret < 0)
4999                 goto out;
5000
5001         p = reply_buf;
5002         rbd_dev->header.object_prefix = ceph_extract_encoded_string(&p,
5003                                                 p + ret, NULL, GFP_NOIO);
5004         ret = 0;
5005
5006         if (IS_ERR(rbd_dev->header.object_prefix)) {
5007                 ret = PTR_ERR(rbd_dev->header.object_prefix);
5008                 rbd_dev->header.object_prefix = NULL;
5009         } else {
5010                 dout("  object_prefix = %s\n", rbd_dev->header.object_prefix);
5011         }
5012 out:
5013         kfree(reply_buf);
5014
5015         return ret;
5016 }
5017
5018 static int _rbd_dev_v2_snap_features(struct rbd_device *rbd_dev, u64 snap_id,
5019                 u64 *snap_features)
5020 {
5021         __le64 snapid = cpu_to_le64(snap_id);
5022         struct {
5023                 __le64 features;
5024                 __le64 incompat;
5025         } __attribute__ ((packed)) features_buf = { 0 };
5026         u64 unsup;
5027         int ret;
5028
5029         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5030                                 "rbd", "get_features",
5031                                 &snapid, sizeof (snapid),
5032                                 &features_buf, sizeof (features_buf));
5033         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5034         if (ret < 0)
5035                 return ret;
5036         if (ret < sizeof (features_buf))
5037                 return -ERANGE;
5038
5039         unsup = le64_to_cpu(features_buf.incompat) & ~RBD_FEATURES_SUPPORTED;
5040         if (unsup) {
5041                 rbd_warn(rbd_dev, "image uses unsupported features: 0x%llx",
5042                          unsup);
5043                 return -ENXIO;
5044         }
5045
5046         *snap_features = le64_to_cpu(features_buf.features);
5047
5048         dout("  snap_id 0x%016llx features = 0x%016llx incompat = 0x%016llx\n",
5049                 (unsigned long long)snap_id,
5050                 (unsigned long long)*snap_features,
5051                 (unsigned long long)le64_to_cpu(features_buf.incompat));
5052
5053         return 0;
5054 }
5055
5056 static int rbd_dev_v2_features(struct rbd_device *rbd_dev)
5057 {
5058         return _rbd_dev_v2_snap_features(rbd_dev, CEPH_NOSNAP,
5059                                                 &rbd_dev->header.features);
5060 }
5061
5062 static int rbd_dev_v2_parent_info(struct rbd_device *rbd_dev)
5063 {
5064         struct rbd_spec *parent_spec;
5065         size_t size;
5066         void *reply_buf = NULL;
5067         __le64 snapid;
5068         void *p;
5069         void *end;
5070         u64 pool_id;
5071         char *image_id;
5072         u64 snap_id;
5073         u64 overlap;
5074         int ret;
5075
5076         parent_spec = rbd_spec_alloc();
5077         if (!parent_spec)
5078                 return -ENOMEM;
5079
5080         size = sizeof (__le64) +                                /* pool_id */
5081                 sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX +        /* image_id */
5082                 sizeof (__le64) +                               /* snap_id */
5083                 sizeof (__le64);                                /* overlap */
5084         reply_buf = kmalloc(size, GFP_KERNEL);
5085         if (!reply_buf) {
5086                 ret = -ENOMEM;
5087                 goto out_err;
5088         }
5089
5090         snapid = cpu_to_le64(rbd_dev->spec->snap_id);
5091         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5092                                 "rbd", "get_parent",
5093                                 &snapid, sizeof (snapid),
5094                                 reply_buf, size);
5095         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5096         if (ret < 0)
5097                 goto out_err;
5098
5099         p = reply_buf;
5100         end = reply_buf + ret;
5101         ret = -ERANGE;
5102         ceph_decode_64_safe(&p, end, pool_id, out_err);
5103         if (pool_id == CEPH_NOPOOL) {
5104                 /*
5105                  * Either the parent never existed, or we have
5106                  * record of it but the image got flattened so it no
5107                  * longer has a parent.  When the parent of a
5108                  * layered image disappears we immediately set the
5109                  * overlap to 0.  The effect of this is that all new
5110                  * requests will be treated as if the image had no
5111                  * parent.
5112                  */
5113                 if (rbd_dev->parent_overlap) {
5114                         rbd_dev->parent_overlap = 0;
5115                         rbd_dev_parent_put(rbd_dev);
5116                         pr_info("%s: clone image has been flattened\n",
5117                                 rbd_dev->disk->disk_name);
5118                 }
5119
5120                 goto out;       /* No parent?  No problem. */
5121         }
5122
5123         /* The ceph file layout needs to fit pool id in 32 bits */
5124
5125         ret = -EIO;
5126         if (pool_id > (u64)U32_MAX) {
5127                 rbd_warn(NULL, "parent pool id too large (%llu > %u)",
5128                         (unsigned long long)pool_id, U32_MAX);
5129                 goto out_err;
5130         }
5131
5132         image_id = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5133         if (IS_ERR(image_id)) {
5134                 ret = PTR_ERR(image_id);
5135                 goto out_err;
5136         }
5137         ceph_decode_64_safe(&p, end, snap_id, out_err);
5138         ceph_decode_64_safe(&p, end, overlap, out_err);
5139
5140         /*
5141          * The parent won't change (except when the clone is
5142          * flattened, already handled that).  So we only need to
5143          * record the parent spec we have not already done so.
5144          */
5145         if (!rbd_dev->parent_spec) {
5146                 parent_spec->pool_id = pool_id;
5147                 parent_spec->image_id = image_id;
5148                 parent_spec->snap_id = snap_id;
5149                 rbd_dev->parent_spec = parent_spec;
5150                 parent_spec = NULL;     /* rbd_dev now owns this */
5151         } else {
5152                 kfree(image_id);
5153         }
5154
5155         /*
5156          * We always update the parent overlap.  If it's zero we issue
5157          * a warning, as we will proceed as if there was no parent.
5158          */
5159         if (!overlap) {
5160                 if (parent_spec) {
5161                         /* refresh, careful to warn just once */
5162                         if (rbd_dev->parent_overlap)
5163                                 rbd_warn(rbd_dev,
5164                                     "clone now standalone (overlap became 0)");
5165                 } else {
5166                         /* initial probe */
5167                         rbd_warn(rbd_dev, "clone is standalone (overlap 0)");
5168                 }
5169         }
5170         rbd_dev->parent_overlap = overlap;
5171
5172 out:
5173         ret = 0;
5174 out_err:
5175         kfree(reply_buf);
5176         rbd_spec_put(parent_spec);
5177
5178         return ret;
5179 }
5180
5181 static int rbd_dev_v2_striping_info(struct rbd_device *rbd_dev)
5182 {
5183         struct {
5184                 __le64 stripe_unit;
5185                 __le64 stripe_count;
5186         } __attribute__ ((packed)) striping_info_buf = { 0 };
5187         size_t size = sizeof (striping_info_buf);
5188         void *p;
5189         u64 obj_size;
5190         u64 stripe_unit;
5191         u64 stripe_count;
5192         int ret;
5193
5194         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5195                                 "rbd", "get_stripe_unit_count", NULL, 0,
5196                                 (char *)&striping_info_buf, size);
5197         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5198         if (ret < 0)
5199                 return ret;
5200         if (ret < size)
5201                 return -ERANGE;
5202
5203         /*
5204          * We don't actually support the "fancy striping" feature
5205          * (STRIPINGV2) yet, but if the striping sizes are the
5206          * defaults the behavior is the same as before.  So find
5207          * out, and only fail if the image has non-default values.
5208          */
5209         ret = -EINVAL;
5210         obj_size = (u64)1 << rbd_dev->header.obj_order;
5211         p = &striping_info_buf;
5212         stripe_unit = ceph_decode_64(&p);
5213         if (stripe_unit != obj_size) {
5214                 rbd_warn(rbd_dev, "unsupported stripe unit "
5215                                 "(got %llu want %llu)",
5216                                 stripe_unit, obj_size);
5217                 return -EINVAL;
5218         }
5219         stripe_count = ceph_decode_64(&p);
5220         if (stripe_count != 1) {
5221                 rbd_warn(rbd_dev, "unsupported stripe count "
5222                                 "(got %llu want 1)", stripe_count);
5223                 return -EINVAL;
5224         }
5225         rbd_dev->header.stripe_unit = stripe_unit;
5226         rbd_dev->header.stripe_count = stripe_count;
5227
5228         return 0;
5229 }
5230
5231 static char *rbd_dev_image_name(struct rbd_device *rbd_dev)
5232 {
5233         size_t image_id_size;
5234         char *image_id;
5235         void *p;
5236         void *end;
5237         size_t size;
5238         void *reply_buf = NULL;
5239         size_t len = 0;
5240         char *image_name = NULL;
5241         int ret;
5242
5243         rbd_assert(!rbd_dev->spec->image_name);
5244
5245         len = strlen(rbd_dev->spec->image_id);
5246         image_id_size = sizeof (__le32) + len;
5247         image_id = kmalloc(image_id_size, GFP_KERNEL);
5248         if (!image_id)
5249                 return NULL;
5250
5251         p = image_id;
5252         end = image_id + image_id_size;
5253         ceph_encode_string(&p, end, rbd_dev->spec->image_id, (u32)len);
5254
5255         size = sizeof (__le32) + RBD_IMAGE_NAME_LEN_MAX;
5256         reply_buf = kmalloc(size, GFP_KERNEL);
5257         if (!reply_buf)
5258                 goto out;
5259
5260         ret = rbd_obj_method_sync(rbd_dev, RBD_DIRECTORY,
5261                                 "rbd", "dir_get_name",
5262                                 image_id, image_id_size,
5263                                 reply_buf, size);
5264         if (ret < 0)
5265                 goto out;
5266         p = reply_buf;
5267         end = reply_buf + ret;
5268
5269         image_name = ceph_extract_encoded_string(&p, end, &len, GFP_KERNEL);
5270         if (IS_ERR(image_name))
5271                 image_name = NULL;
5272         else
5273                 dout("%s: name is %s len is %zd\n", __func__, image_name, len);
5274 out:
5275         kfree(reply_buf);
5276         kfree(image_id);
5277
5278         return image_name;
5279 }
5280
5281 static u64 rbd_v1_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5282 {
5283         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5284         const char *snap_name;
5285         u32 which = 0;
5286
5287         /* Skip over names until we find the one we are looking for */
5288
5289         snap_name = rbd_dev->header.snap_names;
5290         while (which < snapc->num_snaps) {
5291                 if (!strcmp(name, snap_name))
5292                         return snapc->snaps[which];
5293                 snap_name += strlen(snap_name) + 1;
5294                 which++;
5295         }
5296         return CEPH_NOSNAP;
5297 }
5298
5299 static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5300 {
5301         struct ceph_snap_context *snapc = rbd_dev->header.snapc;
5302         u32 which;
5303         bool found = false;
5304         u64 snap_id;
5305
5306         for (which = 0; !found && which < snapc->num_snaps; which++) {
5307                 const char *snap_name;
5308
5309                 snap_id = snapc->snaps[which];
5310                 snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
5311                 if (IS_ERR(snap_name)) {
5312                         /* ignore no-longer existing snapshots */
5313                         if (PTR_ERR(snap_name) == -ENOENT)
5314                                 continue;
5315                         else
5316                                 break;
5317                 }
5318                 found = !strcmp(name, snap_name);
5319                 kfree(snap_name);
5320         }
5321         return found ? snap_id : CEPH_NOSNAP;
5322 }
5323
5324 /*
5325  * Assumes name is never RBD_SNAP_HEAD_NAME; returns CEPH_NOSNAP if
5326  * no snapshot by that name is found, or if an error occurs.
5327  */
5328 static u64 rbd_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)
5329 {
5330         if (rbd_dev->image_format == 1)
5331                 return rbd_v1_snap_id_by_name(rbd_dev, name);
5332
5333         return rbd_v2_snap_id_by_name(rbd_dev, name);
5334 }
5335
5336 /*
5337  * An image being mapped will have everything but the snap id.
5338  */
5339 static int rbd_spec_fill_snap_id(struct rbd_device *rbd_dev)
5340 {
5341         struct rbd_spec *spec = rbd_dev->spec;
5342
5343         rbd_assert(spec->pool_id != CEPH_NOPOOL && spec->pool_name);
5344         rbd_assert(spec->image_id && spec->image_name);
5345         rbd_assert(spec->snap_name);
5346
5347         if (strcmp(spec->snap_name, RBD_SNAP_HEAD_NAME)) {
5348                 u64 snap_id;
5349
5350                 snap_id = rbd_snap_id_by_name(rbd_dev, spec->snap_name);
5351                 if (snap_id == CEPH_NOSNAP)
5352                         return -ENOENT;
5353
5354                 spec->snap_id = snap_id;
5355         } else {
5356                 spec->snap_id = CEPH_NOSNAP;
5357         }
5358
5359         return 0;
5360 }
5361
5362 /*
5363  * A parent image will have all ids but none of the names.
5364  *
5365  * All names in an rbd spec are dynamically allocated.  It's OK if we
5366  * can't figure out the name for an image id.
5367  */
5368 static int rbd_spec_fill_names(struct rbd_device *rbd_dev)
5369 {
5370         struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
5371         struct rbd_spec *spec = rbd_dev->spec;
5372         const char *pool_name;
5373         const char *image_name;
5374         const char *snap_name;
5375         int ret;
5376
5377         rbd_assert(spec->pool_id != CEPH_NOPOOL);
5378         rbd_assert(spec->image_id);
5379         rbd_assert(spec->snap_id != CEPH_NOSNAP);
5380
5381         /* Get the pool name; we have to make our own copy of this */
5382
5383         pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, spec->pool_id);
5384         if (!pool_name) {
5385                 rbd_warn(rbd_dev, "no pool with id %llu", spec->pool_id);
5386                 return -EIO;
5387         }
5388         pool_name = kstrdup(pool_name, GFP_KERNEL);
5389         if (!pool_name)
5390                 return -ENOMEM;
5391
5392         /* Fetch the image name; tolerate failure here */
5393
5394         image_name = rbd_dev_image_name(rbd_dev);
5395         if (!image_name)
5396                 rbd_warn(rbd_dev, "unable to get image name");
5397
5398         /* Fetch the snapshot name */
5399
5400         snap_name = rbd_snap_name(rbd_dev, spec->snap_id);
5401         if (IS_ERR(snap_name)) {
5402                 ret = PTR_ERR(snap_name);
5403                 goto out_err;
5404         }
5405
5406         spec->pool_name = pool_name;
5407         spec->image_name = image_name;
5408         spec->snap_name = snap_name;
5409
5410         return 0;
5411
5412 out_err:
5413         kfree(image_name);
5414         kfree(pool_name);
5415         return ret;
5416 }
5417
5418 static int rbd_dev_v2_snap_context(struct rbd_device *rbd_dev)
5419 {
5420         size_t size;
5421         int ret;
5422         void *reply_buf;
5423         void *p;
5424         void *end;
5425         u64 seq;
5426         u32 snap_count;
5427         struct ceph_snap_context *snapc;
5428         u32 i;
5429
5430         /*
5431          * We'll need room for the seq value (maximum snapshot id),
5432          * snapshot count, and array of that many snapshot ids.
5433          * For now we have a fixed upper limit on the number we're
5434          * prepared to receive.
5435          */
5436         size = sizeof (__le64) + sizeof (__le32) +
5437                         RBD_MAX_SNAP_COUNT * sizeof (__le64);
5438         reply_buf = kzalloc(size, GFP_KERNEL);
5439         if (!reply_buf)
5440                 return -ENOMEM;
5441
5442         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5443                                 "rbd", "get_snapcontext", NULL, 0,
5444                                 reply_buf, size);
5445         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5446         if (ret < 0)
5447                 goto out;
5448
5449         p = reply_buf;
5450         end = reply_buf + ret;
5451         ret = -ERANGE;
5452         ceph_decode_64_safe(&p, end, seq, out);
5453         ceph_decode_32_safe(&p, end, snap_count, out);
5454
5455         /*
5456          * Make sure the reported number of snapshot ids wouldn't go
5457          * beyond the end of our buffer.  But before checking that,
5458          * make sure the computed size of the snapshot context we
5459          * allocate is representable in a size_t.
5460          */
5461         if (snap_count > (SIZE_MAX - sizeof (struct ceph_snap_context))
5462                                  / sizeof (u64)) {
5463                 ret = -EINVAL;
5464                 goto out;
5465         }
5466         if (!ceph_has_room(&p, end, snap_count * sizeof (__le64)))
5467                 goto out;
5468         ret = 0;
5469
5470         snapc = ceph_create_snap_context(snap_count, GFP_KERNEL);
5471         if (!snapc) {
5472                 ret = -ENOMEM;
5473                 goto out;
5474         }
5475         snapc->seq = seq;
5476         for (i = 0; i < snap_count; i++)
5477                 snapc->snaps[i] = ceph_decode_64(&p);
5478
5479         ceph_put_snap_context(rbd_dev->header.snapc);
5480         rbd_dev->header.snapc = snapc;
5481
5482         dout("  snap context seq = %llu, snap_count = %u\n",
5483                 (unsigned long long)seq, (unsigned int)snap_count);
5484 out:
5485         kfree(reply_buf);
5486
5487         return ret;
5488 }
5489
5490 static const char *rbd_dev_v2_snap_name(struct rbd_device *rbd_dev,
5491                                         u64 snap_id)
5492 {
5493         size_t size;
5494         void *reply_buf;
5495         __le64 snapid;
5496         int ret;
5497         void *p;
5498         void *end;
5499         char *snap_name;
5500
5501         size = sizeof (__le32) + RBD_MAX_SNAP_NAME_LEN;
5502         reply_buf = kmalloc(size, GFP_KERNEL);
5503         if (!reply_buf)
5504                 return ERR_PTR(-ENOMEM);
5505
5506         snapid = cpu_to_le64(snap_id);
5507         ret = rbd_obj_method_sync(rbd_dev, rbd_dev->header_oid.name,
5508                                 "rbd", "get_snapshot_name",
5509                                 &snapid, sizeof (snapid),
5510                                 reply_buf, size);
5511         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5512         if (ret < 0) {
5513                 snap_name = ERR_PTR(ret);
5514                 goto out;
5515         }
5516
5517         p = reply_buf;
5518         end = reply_buf + ret;
5519         snap_name = ceph_extract_encoded_string(&p, end, NULL, GFP_KERNEL);
5520         if (IS_ERR(snap_name))
5521                 goto out;
5522
5523         dout("  snap_id 0x%016llx snap_name = %s\n",
5524                 (unsigned long long)snap_id, snap_name);
5525 out:
5526         kfree(reply_buf);
5527
5528         return snap_name;
5529 }
5530
5531 static int rbd_dev_v2_header_info(struct rbd_device *rbd_dev)
5532 {
5533         bool first_time = rbd_dev->header.object_prefix == NULL;
5534         int ret;
5535
5536         ret = rbd_dev_v2_image_size(rbd_dev);
5537         if (ret)
5538                 return ret;
5539
5540         if (first_time) {
5541                 ret = rbd_dev_v2_header_onetime(rbd_dev);
5542                 if (ret)
5543                         return ret;
5544         }
5545
5546         ret = rbd_dev_v2_snap_context(rbd_dev);
5547         if (ret && first_time) {
5548                 kfree(rbd_dev->header.object_prefix);
5549                 rbd_dev->header.object_prefix = NULL;
5550         }
5551
5552         return ret;
5553 }
5554
5555 static int rbd_dev_header_info(struct rbd_device *rbd_dev)
5556 {
5557         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
5558
5559         if (rbd_dev->image_format == 1)
5560                 return rbd_dev_v1_header_info(rbd_dev);
5561
5562         return rbd_dev_v2_header_info(rbd_dev);
5563 }
5564
5565 /*
5566  * Skips over white space at *buf, and updates *buf to point to the
5567  * first found non-space character (if any). Returns the length of
5568  * the token (string of non-white space characters) found.  Note
5569  * that *buf must be terminated with '\0'.
5570  */
5571 static inline size_t next_token(const char **buf)
5572 {
5573         /*
5574         * These are the characters that produce nonzero for
5575         * isspace() in the "C" and "POSIX" locales.
5576         */
5577         const char *spaces = " \f\n\r\t\v";
5578
5579         *buf += strspn(*buf, spaces);   /* Find start of token */
5580
5581         return strcspn(*buf, spaces);   /* Return token length */
5582 }
5583
5584 /*
5585  * Finds the next token in *buf, dynamically allocates a buffer big
5586  * enough to hold a copy of it, and copies the token into the new
5587  * buffer.  The copy is guaranteed to be terminated with '\0'.  Note
5588  * that a duplicate buffer is created even for a zero-length token.
5589  *
5590  * Returns a pointer to the newly-allocated duplicate, or a null
5591  * pointer if memory for the duplicate was not available.  If
5592  * the lenp argument is a non-null pointer, the length of the token
5593  * (not including the '\0') is returned in *lenp.
5594  *
5595  * If successful, the *buf pointer will be updated to point beyond
5596  * the end of the found token.
5597  *
5598  * Note: uses GFP_KERNEL for allocation.
5599  */
5600 static inline char *dup_token(const char **buf, size_t *lenp)
5601 {
5602         char *dup;
5603         size_t len;
5604
5605         len = next_token(buf);
5606         dup = kmemdup(*buf, len + 1, GFP_KERNEL);
5607         if (!dup)
5608                 return NULL;
5609         *(dup + len) = '\0';
5610         *buf += len;
5611
5612         if (lenp)
5613                 *lenp = len;
5614
5615         return dup;
5616 }
5617
5618 /*
5619  * Parse the options provided for an "rbd add" (i.e., rbd image
5620  * mapping) request.  These arrive via a write to /sys/bus/rbd/add,
5621  * and the data written is passed here via a NUL-terminated buffer.
5622  * Returns 0 if successful or an error code otherwise.
5623  *
5624  * The information extracted from these options is recorded in
5625  * the other parameters which return dynamically-allocated
5626  * structures:
5627  *  ceph_opts
5628  *      The address of a pointer that will refer to a ceph options
5629  *      structure.  Caller must release the returned pointer using
5630  *      ceph_destroy_options() when it is no longer needed.
5631  *  rbd_opts
5632  *      Address of an rbd options pointer.  Fully initialized by
5633  *      this function; caller must release with kfree().
5634  *  spec
5635  *      Address of an rbd image specification pointer.  Fully
5636  *      initialized by this function based on parsed options.
5637  *      Caller must release with rbd_spec_put().
5638  *
5639  * The options passed take this form:
5640  *  <mon_addrs> <options> <pool_name> <image_name> [<snap_id>]
5641  * where:
5642  *  <mon_addrs>
5643  *      A comma-separated list of one or more monitor addresses.
5644  *      A monitor address is an ip address, optionally followed
5645  *      by a port number (separated by a colon).
5646  *        I.e.:  ip1[:port1][,ip2[:port2]...]
5647  *  <options>
5648  *      A comma-separated list of ceph and/or rbd options.
5649  *  <pool_name>
5650  *      The name of the rados pool containing the rbd image.
5651  *  <image_name>
5652  *      The name of the image in that pool to map.
5653  *  <snap_id>
5654  *      An optional snapshot id.  If provided, the mapping will
5655  *      present data from the image at the time that snapshot was
5656  *      created.  The image head is used if no snapshot id is
5657  *      provided.  Snapshot mappings are always read-only.
5658  */
5659 static int rbd_add_parse_args(const char *buf,
5660                                 struct ceph_options **ceph_opts,
5661                                 struct rbd_options **opts,
5662                                 struct rbd_spec **rbd_spec)
5663 {
5664         size_t len;
5665         char *options;
5666         const char *mon_addrs;
5667         char *snap_name;
5668         size_t mon_addrs_size;
5669         struct rbd_spec *spec = NULL;
5670         struct rbd_options *rbd_opts = NULL;
5671         struct ceph_options *copts;
5672         int ret;
5673
5674         /* The first four tokens are required */
5675
5676         len = next_token(&buf);
5677         if (!len) {
5678                 rbd_warn(NULL, "no monitor address(es) provided");
5679                 return -EINVAL;
5680         }
5681         mon_addrs = buf;
5682         mon_addrs_size = len + 1;
5683         buf += len;
5684
5685         ret = -EINVAL;
5686         options = dup_token(&buf, NULL);
5687         if (!options)
5688                 return -ENOMEM;
5689         if (!*options) {
5690                 rbd_warn(NULL, "no options provided");
5691                 goto out_err;
5692         }
5693
5694         spec = rbd_spec_alloc();
5695         if (!spec)
5696                 goto out_mem;
5697
5698         spec->pool_name = dup_token(&buf, NULL);
5699         if (!spec->pool_name)
5700                 goto out_mem;
5701         if (!*spec->pool_name) {
5702                 rbd_warn(NULL, "no pool name provided");
5703                 goto out_err;
5704         }
5705
5706         spec->image_name = dup_token(&buf, NULL);
5707         if (!spec->image_name)
5708                 goto out_mem;
5709         if (!*spec->image_name) {
5710                 rbd_warn(NULL, "no image name provided");
5711                 goto out_err;
5712         }
5713
5714         /*
5715          * Snapshot name is optional; default is to use "-"
5716          * (indicating the head/no snapshot).
5717          */
5718         len = next_token(&buf);
5719         if (!len) {
5720                 buf = RBD_SNAP_HEAD_NAME; /* No snapshot supplied */
5721                 len = sizeof (RBD_SNAP_HEAD_NAME) - 1;
5722         } else if (len > RBD_MAX_SNAP_NAME_LEN) {
5723                 ret = -ENAMETOOLONG;
5724                 goto out_err;
5725         }
5726         snap_name = kmemdup(buf, len + 1, GFP_KERNEL);
5727         if (!snap_name)
5728                 goto out_mem;
5729         *(snap_name + len) = '\0';
5730         spec->snap_name = snap_name;
5731
5732         /* Initialize all rbd options to the defaults */
5733
5734         rbd_opts = kzalloc(sizeof (*rbd_opts), GFP_KERNEL);
5735         if (!rbd_opts)
5736                 goto out_mem;
5737
5738         rbd_opts->read_only = RBD_READ_ONLY_DEFAULT;
5739         rbd_opts->queue_depth = RBD_QUEUE_DEPTH_DEFAULT;
5740         rbd_opts->lock_on_read = RBD_LOCK_ON_READ_DEFAULT;
5741
5742         copts = ceph_parse_options(options, mon_addrs,
5743                                         mon_addrs + mon_addrs_size - 1,
5744                                         parse_rbd_opts_token, rbd_opts);
5745         if (IS_ERR(copts)) {
5746                 ret = PTR_ERR(copts);
5747                 goto out_err;
5748         }
5749         kfree(options);
5750
5751         *ceph_opts = copts;
5752         *opts = rbd_opts;
5753         *rbd_spec = spec;
5754
5755         return 0;
5756 out_mem:
5757         ret = -ENOMEM;
5758 out_err:
5759         kfree(rbd_opts);
5760         rbd_spec_put(spec);
5761         kfree(options);
5762
5763         return ret;
5764 }
5765
5766 /*
5767  * Return pool id (>= 0) or a negative error code.
5768  */
5769 static int rbd_add_get_pool_id(struct rbd_client *rbdc, const char *pool_name)
5770 {
5771         struct ceph_options *opts = rbdc->client->options;
5772         u64 newest_epoch;
5773         int tries = 0;
5774         int ret;
5775
5776 again:
5777         ret = ceph_pg_poolid_by_name(rbdc->client->osdc.osdmap, pool_name);
5778         if (ret == -ENOENT && tries++ < 1) {
5779                 ret = ceph_monc_get_version(&rbdc->client->monc, "osdmap",
5780                                             &newest_epoch);
5781                 if (ret < 0)
5782                         return ret;
5783
5784                 if (rbdc->client->osdc.osdmap->epoch < newest_epoch) {
5785                         ceph_osdc_maybe_request_map(&rbdc->client->osdc);
5786                         (void) ceph_monc_wait_osdmap(&rbdc->client->monc,
5787                                                      newest_epoch,
5788                                                      opts->mount_timeout);
5789                         goto again;
5790                 } else {
5791                         /* the osdmap we have is new enough */
5792                         return -ENOENT;
5793                 }
5794         }
5795
5796         return ret;
5797 }
5798
5799 /*
5800  * An rbd format 2 image has a unique identifier, distinct from the
5801  * name given to it by the user.  Internally, that identifier is
5802  * what's used to specify the names of objects related to the image.
5803  *
5804  * A special "rbd id" object is used to map an rbd image name to its
5805  * id.  If that object doesn't exist, then there is no v2 rbd image
5806  * with the supplied name.
5807  *
5808  * This function will record the given rbd_dev's image_id field if
5809  * it can be determined, and in that case will return 0.  If any
5810  * errors occur a negative errno will be returned and the rbd_dev's
5811  * image_id field will be unchanged (and should be NULL).
5812  */
5813 static int rbd_dev_image_id(struct rbd_device *rbd_dev)
5814 {
5815         int ret;
5816         size_t size;
5817         char *object_name;
5818         void *response;
5819         char *image_id;
5820
5821         /*
5822          * When probing a parent image, the image id is already
5823          * known (and the image name likely is not).  There's no
5824          * need to fetch the image id again in this case.  We
5825          * do still need to set the image format though.
5826          */
5827         if (rbd_dev->spec->image_id) {
5828                 rbd_dev->image_format = *rbd_dev->spec->image_id ? 2 : 1;
5829
5830                 return 0;
5831         }
5832
5833         /*
5834          * First, see if the format 2 image id file exists, and if
5835          * so, get the image's persistent id from it.
5836          */
5837         size = sizeof (RBD_ID_PREFIX) + strlen(rbd_dev->spec->image_name);
5838         object_name = kmalloc(size, GFP_NOIO);
5839         if (!object_name)
5840                 return -ENOMEM;
5841         sprintf(object_name, "%s%s", RBD_ID_PREFIX, rbd_dev->spec->image_name);
5842         dout("rbd id object name is %s\n", object_name);
5843
5844         /* Response will be an encoded string, which includes a length */
5845
5846         size = sizeof (__le32) + RBD_IMAGE_ID_LEN_MAX;
5847         response = kzalloc(size, GFP_NOIO);
5848         if (!response) {
5849                 ret = -ENOMEM;
5850                 goto out;
5851         }
5852
5853         /* If it doesn't exist we'll assume it's a format 1 image */
5854
5855         ret = rbd_obj_method_sync(rbd_dev, object_name,
5856                                 "rbd", "get_id", NULL, 0,
5857                                 response, RBD_IMAGE_ID_LEN_MAX);
5858         dout("%s: rbd_obj_method_sync returned %d\n", __func__, ret);
5859         if (ret == -ENOENT) {
5860                 image_id = kstrdup("", GFP_KERNEL);
5861                 ret = image_id ? 0 : -ENOMEM;
5862                 if (!ret)
5863                         rbd_dev->image_format = 1;
5864         } else if (ret >= 0) {
5865                 void *p = response;
5866
5867                 image_id = ceph_extract_encoded_string(&p, p + ret,
5868                                                 NULL, GFP_NOIO);
5869                 ret = PTR_ERR_OR_ZERO(image_id);
5870                 if (!ret)
5871                         rbd_dev->image_format = 2;
5872         }
5873
5874         if (!ret) {
5875                 rbd_dev->spec->image_id = image_id;
5876                 dout("image_id is %s\n", image_id);
5877         }
5878 out:
5879         kfree(response);
5880         kfree(object_name);
5881
5882         return ret;
5883 }
5884
5885 /*
5886  * Undo whatever state changes are made by v1 or v2 header info
5887  * call.
5888  */
5889 static void rbd_dev_unprobe(struct rbd_device *rbd_dev)
5890 {
5891         struct rbd_image_header *header;
5892
5893         rbd_dev_parent_put(rbd_dev);
5894
5895         /* Free dynamic fields from the header, then zero it out */
5896
5897         header = &rbd_dev->header;
5898         ceph_put_snap_context(header->snapc);
5899         kfree(header->snap_sizes);
5900         kfree(header->snap_names);
5901         kfree(header->object_prefix);
5902         memset(header, 0, sizeof (*header));
5903 }
5904
5905 static int rbd_dev_v2_header_onetime(struct rbd_device *rbd_dev)
5906 {
5907         int ret;
5908
5909         ret = rbd_dev_v2_object_prefix(rbd_dev);
5910         if (ret)
5911                 goto out_err;
5912
5913         /*
5914          * Get the and check features for the image.  Currently the
5915          * features are assumed to never change.
5916          */
5917         ret = rbd_dev_v2_features(rbd_dev);
5918         if (ret)
5919                 goto out_err;
5920
5921         /* If the image supports fancy striping, get its parameters */
5922
5923         if (rbd_dev->header.features & RBD_FEATURE_STRIPINGV2) {
5924                 ret = rbd_dev_v2_striping_info(rbd_dev);
5925                 if (ret < 0)
5926                         goto out_err;
5927         }
5928         /* No support for crypto and compression type format 2 images */
5929
5930         return 0;
5931 out_err:
5932         rbd_dev->header.features = 0;
5933         kfree(rbd_dev->header.object_prefix);
5934         rbd_dev->header.object_prefix = NULL;
5935
5936         return ret;
5937 }
5938
5939 /*
5940  * @depth is rbd_dev_image_probe() -> rbd_dev_probe_parent() ->
5941  * rbd_dev_image_probe() recursion depth, which means it's also the
5942  * length of the already discovered part of the parent chain.
5943  */
5944 static int rbd_dev_probe_parent(struct rbd_device *rbd_dev, int depth)
5945 {
5946         struct rbd_device *parent = NULL;
5947         int ret;
5948
5949         if (!rbd_dev->parent_spec)
5950                 return 0;
5951
5952         if (++depth > RBD_MAX_PARENT_CHAIN_LEN) {
5953                 pr_info("parent chain is too long (%d)\n", depth);
5954                 ret = -EINVAL;
5955                 goto out_err;
5956         }
5957
5958         parent = __rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
5959         if (!parent) {
5960                 ret = -ENOMEM;
5961                 goto out_err;
5962         }
5963
5964         /*
5965          * Images related by parent/child relationships always share
5966          * rbd_client and spec/parent_spec, so bump their refcounts.
5967          */
5968         __rbd_get_client(rbd_dev->rbd_client);
5969         rbd_spec_get(rbd_dev->parent_spec);
5970
5971         ret = rbd_dev_image_probe(parent, depth);
5972         if (ret < 0)
5973                 goto out_err;
5974
5975         rbd_dev->parent = parent;
5976         atomic_set(&rbd_dev->parent_ref, 1);
5977         return 0;
5978
5979 out_err:
5980         rbd_dev_unparent(rbd_dev);
5981         rbd_dev_destroy(parent);
5982         return ret;
5983 }
5984
5985 /*
5986  * rbd_dev->header_rwsem must be locked for write and will be unlocked
5987  * upon return.
5988  */
5989 static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
5990 {
5991         int ret;
5992
5993         /* Record our major and minor device numbers. */
5994
5995         if (!single_major) {
5996                 ret = register_blkdev(0, rbd_dev->name);
5997                 if (ret < 0)
5998                         goto err_out_unlock;
5999
6000                 rbd_dev->major = ret;
6001                 rbd_dev->minor = 0;
6002         } else {
6003                 rbd_dev->major = rbd_major;
6004                 rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
6005         }
6006
6007         /* Set up the blkdev mapping. */
6008
6009         ret = rbd_init_disk(rbd_dev);
6010         if (ret)
6011                 goto err_out_blkdev;
6012
6013         ret = rbd_dev_mapping_set(rbd_dev);
6014         if (ret)
6015                 goto err_out_disk;
6016
6017         set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
6018         set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
6019
6020         dev_set_name(&rbd_dev->dev, "%d", rbd_dev->dev_id);
6021         ret = device_add(&rbd_dev->dev);
6022         if (ret)
6023                 goto err_out_mapping;
6024
6025         /* Everything's ready.  Announce the disk to the world. */
6026
6027         set_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6028         up_write(&rbd_dev->header_rwsem);
6029
6030         spin_lock(&rbd_dev_list_lock);
6031         list_add_tail(&rbd_dev->node, &rbd_dev_list);
6032         spin_unlock(&rbd_dev_list_lock);
6033
6034         add_disk(rbd_dev->disk);
6035         pr_info("%s: capacity %llu features 0x%llx\n", rbd_dev->disk->disk_name,
6036                 (unsigned long long)get_capacity(rbd_dev->disk) << SECTOR_SHIFT,
6037                 rbd_dev->header.features);
6038
6039         return ret;
6040
6041 err_out_mapping:
6042         rbd_dev_mapping_clear(rbd_dev);
6043 err_out_disk:
6044         rbd_free_disk(rbd_dev);
6045 err_out_blkdev:
6046         if (!single_major)
6047                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6048 err_out_unlock:
6049         up_write(&rbd_dev->header_rwsem);
6050         return ret;
6051 }
6052
6053 static int rbd_dev_header_name(struct rbd_device *rbd_dev)
6054 {
6055         struct rbd_spec *spec = rbd_dev->spec;
6056         int ret;
6057
6058         /* Record the header object name for this rbd image. */
6059
6060         rbd_assert(rbd_image_format_valid(rbd_dev->image_format));
6061
6062         rbd_dev->header_oloc.pool = rbd_dev->layout.pool_id;
6063         if (rbd_dev->image_format == 1)
6064                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6065                                        spec->image_name, RBD_SUFFIX);
6066         else
6067                 ret = ceph_oid_aprintf(&rbd_dev->header_oid, GFP_KERNEL, "%s%s",
6068                                        RBD_HEADER_PREFIX, spec->image_id);
6069
6070         return ret;
6071 }
6072
6073 static void rbd_dev_image_release(struct rbd_device *rbd_dev)
6074 {
6075         rbd_dev_unprobe(rbd_dev);
6076         rbd_dev->image_format = 0;
6077         kfree(rbd_dev->spec->image_id);
6078         rbd_dev->spec->image_id = NULL;
6079
6080         rbd_dev_destroy(rbd_dev);
6081 }
6082
6083 /*
6084  * Probe for the existence of the header object for the given rbd
6085  * device.  If this image is the one being mapped (i.e., not a
6086  * parent), initiate a watch on its header object before using that
6087  * object to get detailed information about the rbd image.
6088  */
6089 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, int depth)
6090 {
6091         int ret;
6092
6093         /*
6094          * Get the id from the image id object.  Unless there's an
6095          * error, rbd_dev->spec->image_id will be filled in with
6096          * a dynamically-allocated string, and rbd_dev->image_format
6097          * will be set to either 1 or 2.
6098          */
6099         ret = rbd_dev_image_id(rbd_dev);
6100         if (ret)
6101                 return ret;
6102
6103         ret = rbd_dev_header_name(rbd_dev);
6104         if (ret)
6105                 goto err_out_format;
6106
6107         if (!depth) {
6108                 ret = rbd_register_watch(rbd_dev);
6109                 if (ret) {
6110                         if (ret == -ENOENT)
6111                                 pr_info("image %s/%s does not exist\n",
6112                                         rbd_dev->spec->pool_name,
6113                                         rbd_dev->spec->image_name);
6114                         goto err_out_format;
6115                 }
6116         }
6117
6118         ret = rbd_dev_header_info(rbd_dev);
6119         if (ret)
6120                 goto err_out_watch;
6121
6122         /*
6123          * If this image is the one being mapped, we have pool name and
6124          * id, image name and id, and snap name - need to fill snap id.
6125          * Otherwise this is a parent image, identified by pool, image
6126          * and snap ids - need to fill in names for those ids.
6127          */
6128         if (!depth)
6129                 ret = rbd_spec_fill_snap_id(rbd_dev);
6130         else
6131                 ret = rbd_spec_fill_names(rbd_dev);
6132         if (ret) {
6133                 if (ret == -ENOENT)
6134                         pr_info("snap %s/%s@%s does not exist\n",
6135                                 rbd_dev->spec->pool_name,
6136                                 rbd_dev->spec->image_name,
6137                                 rbd_dev->spec->snap_name);
6138                 goto err_out_probe;
6139         }
6140
6141         if (rbd_dev->header.features & RBD_FEATURE_LAYERING) {
6142                 ret = rbd_dev_v2_parent_info(rbd_dev);
6143                 if (ret)
6144                         goto err_out_probe;
6145
6146                 /*
6147                  * Need to warn users if this image is the one being
6148                  * mapped and has a parent.
6149                  */
6150                 if (!depth && rbd_dev->parent_spec)
6151                         rbd_warn(rbd_dev,
6152                                  "WARNING: kernel layering is EXPERIMENTAL!");
6153         }
6154
6155         ret = rbd_dev_probe_parent(rbd_dev, depth);
6156         if (ret)
6157                 goto err_out_probe;
6158
6159         dout("discovered format %u image, header name is %s\n",
6160                 rbd_dev->image_format, rbd_dev->header_oid.name);
6161         return 0;
6162
6163 err_out_probe:
6164         rbd_dev_unprobe(rbd_dev);
6165 err_out_watch:
6166         if (!depth)
6167                 rbd_unregister_watch(rbd_dev);
6168 err_out_format:
6169         rbd_dev->image_format = 0;
6170         kfree(rbd_dev->spec->image_id);
6171         rbd_dev->spec->image_id = NULL;
6172         return ret;
6173 }
6174
6175 static ssize_t do_rbd_add(struct bus_type *bus,
6176                           const char *buf,
6177                           size_t count)
6178 {
6179         struct rbd_device *rbd_dev = NULL;
6180         struct ceph_options *ceph_opts = NULL;
6181         struct rbd_options *rbd_opts = NULL;
6182         struct rbd_spec *spec = NULL;
6183         struct rbd_client *rbdc;
6184         bool read_only;
6185         int rc;
6186
6187         if (!try_module_get(THIS_MODULE))
6188                 return -ENODEV;
6189
6190         /* parse add command */
6191         rc = rbd_add_parse_args(buf, &ceph_opts, &rbd_opts, &spec);
6192         if (rc < 0)
6193                 goto out;
6194
6195         rbdc = rbd_get_client(ceph_opts);
6196         if (IS_ERR(rbdc)) {
6197                 rc = PTR_ERR(rbdc);
6198                 goto err_out_args;
6199         }
6200
6201         /* pick the pool */
6202         rc = rbd_add_get_pool_id(rbdc, spec->pool_name);
6203         if (rc < 0) {
6204                 if (rc == -ENOENT)
6205                         pr_info("pool %s does not exist\n", spec->pool_name);
6206                 goto err_out_client;
6207         }
6208         spec->pool_id = (u64)rc;
6209
6210         rbd_dev = rbd_dev_create(rbdc, spec, rbd_opts);
6211         if (!rbd_dev) {
6212                 rc = -ENOMEM;
6213                 goto err_out_client;
6214         }
6215         rbdc = NULL;            /* rbd_dev now owns this */
6216         spec = NULL;            /* rbd_dev now owns this */
6217         rbd_opts = NULL;        /* rbd_dev now owns this */
6218
6219         rbd_dev->config_info = kstrdup(buf, GFP_KERNEL);
6220         if (!rbd_dev->config_info) {
6221                 rc = -ENOMEM;
6222                 goto err_out_rbd_dev;
6223         }
6224
6225         down_write(&rbd_dev->header_rwsem);
6226         rc = rbd_dev_image_probe(rbd_dev, 0);
6227         if (rc < 0) {
6228                 up_write(&rbd_dev->header_rwsem);
6229                 goto err_out_rbd_dev;
6230         }
6231
6232         /* If we are mapping a snapshot it must be marked read-only */
6233
6234         read_only = rbd_dev->opts->read_only;
6235         if (rbd_dev->spec->snap_id != CEPH_NOSNAP)
6236                 read_only = true;
6237         rbd_dev->mapping.read_only = read_only;
6238
6239         rc = rbd_dev_device_setup(rbd_dev);
6240         if (rc) {
6241                 /*
6242                  * rbd_unregister_watch() can't be moved into
6243                  * rbd_dev_image_release() without refactoring, see
6244                  * commit 1f3ef78861ac.
6245                  */
6246                 rbd_unregister_watch(rbd_dev);
6247                 rbd_dev_image_release(rbd_dev);
6248                 goto out;
6249         }
6250
6251         rc = count;
6252 out:
6253         module_put(THIS_MODULE);
6254         return rc;
6255
6256 err_out_rbd_dev:
6257         rbd_dev_destroy(rbd_dev);
6258 err_out_client:
6259         rbd_put_client(rbdc);
6260 err_out_args:
6261         rbd_spec_put(spec);
6262         kfree(rbd_opts);
6263         goto out;
6264 }
6265
6266 static ssize_t rbd_add(struct bus_type *bus,
6267                        const char *buf,
6268                        size_t count)
6269 {
6270         if (single_major)
6271                 return -EINVAL;
6272
6273         return do_rbd_add(bus, buf, count);
6274 }
6275
6276 static ssize_t rbd_add_single_major(struct bus_type *bus,
6277                                     const char *buf,
6278                                     size_t count)
6279 {
6280         return do_rbd_add(bus, buf, count);
6281 }
6282
6283 static void rbd_dev_device_release(struct rbd_device *rbd_dev)
6284 {
6285         rbd_free_disk(rbd_dev);
6286
6287         spin_lock(&rbd_dev_list_lock);
6288         list_del_init(&rbd_dev->node);
6289         spin_unlock(&rbd_dev_list_lock);
6290
6291         clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
6292         device_del(&rbd_dev->dev);
6293         rbd_dev_mapping_clear(rbd_dev);
6294         if (!single_major)
6295                 unregister_blkdev(rbd_dev->major, rbd_dev->name);
6296 }
6297
6298 static void rbd_dev_remove_parent(struct rbd_device *rbd_dev)
6299 {
6300         while (rbd_dev->parent) {
6301                 struct rbd_device *first = rbd_dev;
6302                 struct rbd_device *second = first->parent;
6303                 struct rbd_device *third;
6304
6305                 /*
6306                  * Follow to the parent with no grandparent and
6307                  * remove it.
6308                  */
6309                 while (second && (third = second->parent)) {
6310                         first = second;
6311                         second = third;
6312                 }
6313                 rbd_assert(second);
6314                 rbd_dev_image_release(second);
6315                 first->parent = NULL;
6316                 first->parent_overlap = 0;
6317
6318                 rbd_assert(first->parent_spec);
6319                 rbd_spec_put(first->parent_spec);
6320                 first->parent_spec = NULL;
6321         }
6322 }
6323
6324 static ssize_t do_rbd_remove(struct bus_type *bus,
6325                              const char *buf,
6326                              size_t count)
6327 {
6328         struct rbd_device *rbd_dev = NULL;
6329         struct list_head *tmp;
6330         int dev_id;
6331         char opt_buf[6];
6332         bool already = false;
6333         bool force = false;
6334         int ret;
6335
6336         dev_id = -1;
6337         opt_buf[0] = '\0';
6338         sscanf(buf, "%d %5s", &dev_id, opt_buf);
6339         if (dev_id < 0) {
6340                 pr_err("dev_id out of range\n");
6341                 return -EINVAL;
6342         }
6343         if (opt_buf[0] != '\0') {
6344                 if (!strcmp(opt_buf, "force")) {
6345                         force = true;
6346                 } else {
6347                         pr_err("bad remove option at '%s'\n", opt_buf);
6348                         return -EINVAL;
6349                 }
6350         }
6351
6352         ret = -ENOENT;
6353         spin_lock(&rbd_dev_list_lock);
6354         list_for_each(tmp, &rbd_dev_list) {
6355                 rbd_dev = list_entry(tmp, struct rbd_device, node);
6356                 if (rbd_dev->dev_id == dev_id) {
6357                         ret = 0;
6358                         break;
6359                 }
6360         }
6361         if (!ret) {
6362                 spin_lock_irq(&rbd_dev->lock);
6363                 if (rbd_dev->open_count && !force)
6364                         ret = -EBUSY;
6365                 else
6366                         already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
6367                                                         &rbd_dev->flags);
6368                 spin_unlock_irq(&rbd_dev->lock);
6369         }
6370         spin_unlock(&rbd_dev_list_lock);
6371         if (ret < 0 || already)
6372                 return ret;
6373
6374         if (force) {
6375                 /*
6376                  * Prevent new IO from being queued and wait for existing
6377                  * IO to complete/fail.
6378                  */
6379                 blk_mq_freeze_queue(rbd_dev->disk->queue);
6380                 blk_set_queue_dying(rbd_dev->disk->queue);
6381         }
6382
6383         down_write(&rbd_dev->lock_rwsem);
6384         if (__rbd_is_lock_owner(rbd_dev))
6385                 rbd_unlock(rbd_dev);
6386         up_write(&rbd_dev->lock_rwsem);
6387         rbd_unregister_watch(rbd_dev);
6388
6389         /*
6390          * Don't free anything from rbd_dev->disk until after all
6391          * notifies are completely processed. Otherwise
6392          * rbd_bus_del_dev() will race with rbd_watch_cb(), resulting
6393          * in a potential use after free of rbd_dev->disk or rbd_dev.
6394          */
6395         rbd_dev_device_release(rbd_dev);
6396         rbd_dev_image_release(rbd_dev);
6397
6398         return count;
6399 }
6400
6401 static ssize_t rbd_remove(struct bus_type *bus,
6402                           const char *buf,
6403                           size_t count)
6404 {
6405         if (single_major)
6406                 return -EINVAL;
6407
6408         return do_rbd_remove(bus, buf, count);
6409 }
6410
6411 static ssize_t rbd_remove_single_major(struct bus_type *bus,
6412                                        const char *buf,
6413                                        size_t count)
6414 {
6415         return do_rbd_remove(bus, buf, count);
6416 }
6417
6418 /*
6419  * create control files in sysfs
6420  * /sys/bus/rbd/...
6421  */
6422 static int rbd_sysfs_init(void)
6423 {
6424         int ret;
6425
6426         ret = device_register(&rbd_root_dev);
6427         if (ret < 0)
6428                 return ret;
6429
6430         ret = bus_register(&rbd_bus_type);
6431         if (ret < 0)
6432                 device_unregister(&rbd_root_dev);
6433
6434         return ret;
6435 }
6436
6437 static void rbd_sysfs_cleanup(void)
6438 {
6439         bus_unregister(&rbd_bus_type);
6440         device_unregister(&rbd_root_dev);
6441 }
6442
6443 static int rbd_slab_init(void)
6444 {
6445         rbd_assert(!rbd_img_request_cache);
6446         rbd_img_request_cache = KMEM_CACHE(rbd_img_request, 0);
6447         if (!rbd_img_request_cache)
6448                 return -ENOMEM;
6449
6450         rbd_assert(!rbd_obj_request_cache);
6451         rbd_obj_request_cache = KMEM_CACHE(rbd_obj_request, 0);
6452         if (!rbd_obj_request_cache)
6453                 goto out_err;
6454
6455         rbd_assert(!rbd_segment_name_cache);
6456         rbd_segment_name_cache = kmem_cache_create("rbd_segment_name",
6457                                         CEPH_MAX_OID_NAME_LEN + 1, 1, 0, NULL);
6458         if (rbd_segment_name_cache)
6459                 return 0;
6460 out_err:
6461         kmem_cache_destroy(rbd_obj_request_cache);
6462         rbd_obj_request_cache = NULL;
6463
6464         kmem_cache_destroy(rbd_img_request_cache);
6465         rbd_img_request_cache = NULL;
6466
6467         return -ENOMEM;
6468 }
6469
6470 static void rbd_slab_exit(void)
6471 {
6472         rbd_assert(rbd_segment_name_cache);
6473         kmem_cache_destroy(rbd_segment_name_cache);
6474         rbd_segment_name_cache = NULL;
6475
6476         rbd_assert(rbd_obj_request_cache);
6477         kmem_cache_destroy(rbd_obj_request_cache);
6478         rbd_obj_request_cache = NULL;
6479
6480         rbd_assert(rbd_img_request_cache);
6481         kmem_cache_destroy(rbd_img_request_cache);
6482         rbd_img_request_cache = NULL;
6483 }
6484
6485 static int __init rbd_init(void)
6486 {
6487         int rc;
6488
6489         if (!libceph_compatible(NULL)) {
6490                 rbd_warn(NULL, "libceph incompatibility (quitting)");
6491                 return -EINVAL;
6492         }
6493
6494         rc = rbd_slab_init();
6495         if (rc)
6496                 return rc;
6497
6498         /*
6499          * The number of active work items is limited by the number of
6500          * rbd devices * queue depth, so leave @max_active at default.
6501          */
6502         rbd_wq = alloc_workqueue(RBD_DRV_NAME, WQ_MEM_RECLAIM, 0);
6503         if (!rbd_wq) {
6504                 rc = -ENOMEM;
6505                 goto err_out_slab;
6506         }
6507
6508         if (single_major) {
6509                 rbd_major = register_blkdev(0, RBD_DRV_NAME);
6510                 if (rbd_major < 0) {
6511                         rc = rbd_major;
6512                         goto err_out_wq;
6513                 }
6514         }
6515
6516         rc = rbd_sysfs_init();
6517         if (rc)
6518                 goto err_out_blkdev;
6519
6520         if (single_major)
6521                 pr_info("loaded (major %d)\n", rbd_major);
6522         else
6523                 pr_info("loaded\n");
6524
6525         return 0;
6526
6527 err_out_blkdev:
6528         if (single_major)
6529                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
6530 err_out_wq:
6531         destroy_workqueue(rbd_wq);
6532 err_out_slab:
6533         rbd_slab_exit();
6534         return rc;
6535 }
6536
6537 static void __exit rbd_exit(void)
6538 {
6539         ida_destroy(&rbd_dev_id_ida);
6540         rbd_sysfs_cleanup();
6541         if (single_major)
6542                 unregister_blkdev(rbd_major, RBD_DRV_NAME);
6543         destroy_workqueue(rbd_wq);
6544         rbd_slab_exit();
6545 }
6546
6547 module_init(rbd_init);
6548 module_exit(rbd_exit);
6549
6550 MODULE_AUTHOR("Alex Elder <elder@inktank.com>");
6551 MODULE_AUTHOR("Sage Weil <sage@newdream.net>");
6552 MODULE_AUTHOR("Yehuda Sadeh <yehuda@hq.newdream.net>");
6553 /* following authorship retained from original osdblk.c */
6554 MODULE_AUTHOR("Jeff Garzik <jeff@garzik.org>");
6555
6556 MODULE_DESCRIPTION("RADOS Block Device (RBD) driver");
6557 MODULE_LICENSE("GPL");