drivers/scsi/sg.c

   1 /*
   2  *  History:
   3  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
   4  *           to allow user process control of SCSI devices.
   5  *  Development Sponsored by Killy Corp. NY NY
   6  *
   7  * Original driver (sg.c):
   8  *        Copyright (C) 1992 Lawrence Foard
   9  * Version 2 and 3 extensions to driver:
  10  *        Copyright (C) 1998 - 2014 Douglas Gilbert
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  */
  18
  19 static int sg_version_num = 30536;      /* 2 digits for each component */
  20 #define SG_VERSION_STR "3.5.36"
  21
  22 /*
  23  *  D. P. Gilbert (dgilbert@interlog.com), notes:
  24  *      - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
  25  *        the kernel/module needs to be built with CONFIG_SCSI_LOGGING
  26  *        (otherwise the macros compile to empty statements).
  27  *
  28  */
  29 #include <linux/module.h>
  30
  31 #include <linux/fs.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/string.h>
  35 #include <linux/mm.h>
  36 #include <linux/aio.h>
  37 #include <linux/errno.h>
  38 #include <linux/mtio.h>
  39 #include <linux/ioctl.h>
  40 #include <linux/slab.h>
  41 #include <linux/fcntl.h>
  42 #include <linux/init.h>
  43 #include <linux/poll.h>
  44 #include <linux/moduleparam.h>
  45 #include <linux/cdev.h>
  46 #include <linux/idr.h>
  47 #include <linux/seq_file.h>
  48 #include <linux/blkdev.h>
  49 #include <linux/delay.h>
  50 #include <linux/blktrace_api.h>
  51 #include <linux/mutex.h>
  52 #include <linux/atomic.h>
  53 #include <linux/ratelimit.h>
  54
  55 #include "scsi.h"
  56 #include <scsi/scsi_dbg.h>
  57 #include <scsi/scsi_host.h>
  58 #include <scsi/scsi_driver.h>
  59 #include <scsi/scsi_ioctl.h>
  60 #include <scsi/sg.h>
  61
  62 #include "scsi_logging.h"
  63
  64 #ifdef CONFIG_SCSI_PROC_FS
  65 #include <linux/proc_fs.h>
  66 static char *sg_version_date = "20140603";
  67
  68 static int sg_proc_init(void);
  69 static void sg_proc_cleanup(void);
  70 #endif
  71
  72 #define SG_ALLOW_DIO_DEF 0
  73
  74 #define SG_MAX_DEVS 32768
  75
  76 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
  77  * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
  78  * than 16 bytes are "variable length" whose length is a multiple of 4
  79  */
  80 #define SG_MAX_CDB_SIZE 252
  81
  82 /*
  83  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
  84  * Then when using 32 bit integers x * m may overflow during the calculation.
  85  * Replacing muldiv(x) by muldiv(x)=((x % d) * m) / d + int(x / d) * m
  86  * calculates the same, but prevents the overflow when both m and d
  87  * are "small" numbers (like HZ and USER_HZ).
  88  * Of course an overflow is inavoidable if the result of muldiv doesn't fit
  89  * in 32 bits.
  90  */
  91 #define MULDIV(X,MUL,DIV) ((((X % DIV) * MUL) / DIV) + ((X / DIV) * MUL))
  92
  93 #define SG_DEFAULT_TIMEOUT MULDIV(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
  94
  95 int sg_big_buff = SG_DEF_RESERVED_SIZE;
  96 /* N.B. This variable is readable and writeable via
  97    /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
  98    of this size (or less if there is not enough memory) will be reserved
  99    for use by this file descriptor. [Deprecated usage: this variable is also
 100    readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
 101    the kernel (i.e. it is not a module).] */
 102 static int def_reserved_size = -1;      /* picks up init parameter */
 103 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
 104
 105 static int scatter_elem_sz = SG_SCATTER_SZ;
 106 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
 107
 108 #define SG_SECTOR_SZ 512
 109
 110 static int sg_add_device(struct device *, struct class_interface *);
 111 static void sg_remove_device(struct device *, struct class_interface *);
 112
 113 static DEFINE_IDR(sg_index_idr);
 114 static DEFINE_RWLOCK(sg_index_lock);    /* Also used to lock
 115                                                            file descriptor list for device */
 116
 117 static struct class_interface sg_interface = {
 118         .add_dev        = sg_add_device,
 119         .remove_dev     = sg_remove_device,
 120 };
 121
 122 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 123         unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 124         unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 125         unsigned bufflen;       /* Size of (aggregate) data buffer */
 126         struct page **pages;
 127         int page_order;
 128         char dio_in_use;        /* 0->indirect IO (or mmap), 1->dio */
 129         unsigned char cmd_opcode; /* first byte of command */
 130 } Sg_scatter_hold;
 131
 132 struct sg_device;               /* forward declarations */
 133 struct sg_fd;
 134
 135 typedef struct sg_request {     /* SG_MAX_QUEUE requests outstanding per file */
 136         struct sg_request *nextrp;      /* NULL -> tail request (slist) */
 137         struct sg_fd *parentfp; /* NULL -> not in use */
 138         Sg_scatter_hold data;   /* hold buffer, perhaps scatter list */
 139         sg_io_hdr_t header;     /* scsi command+info, see <scsi/sg.h> */
 140         unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
 141         char res_used;          /* 1 -> using reserve buffer, 0 -> not ... */
 142         char orphan;            /* 1 -> drop on sight, 0 -> normal */
 143         char sg_io_owned;       /* 1 -> packet belongs to SG_IO */
 144         /* done protected by rq_list_lock */
 145         char done;              /* 0->before bh, 1->before read, 2->read */
 146         struct request *rq;
 147         struct bio *bio;
 148         struct execute_work ew;
 149 } Sg_request;
 150
 151 typedef struct sg_fd {          /* holds the state of a file descriptor */
 152         struct list_head sfd_siblings;  /* protected by device's sfd_lock */
 153         struct sg_device *parentdp;     /* owning device */
 154         wait_queue_head_t read_wait;    /* queue read until command done */
 155         rwlock_t rq_list_lock;  /* protect access to list in req_arr */
 156         int timeout;            /* defaults to SG_DEFAULT_TIMEOUT      */
 157         int timeout_user;       /* defaults to SG_DEFAULT_TIMEOUT_USER */
 158         Sg_scatter_hold reserve;        /* buffer held for this file descriptor */
 159         unsigned save_scat_len; /* original length of trunc. scat. element */
 160         Sg_request *headrp;     /* head of request slist, NULL->empty */
 161         struct fasync_struct *async_qp; /* used by asynchronous notification */
 162         Sg_request req_arr[SG_MAX_QUEUE];       /* used as singly-linked list */
 163         char low_dma;           /* as in parent but possibly overridden to 1 */
 164         char force_packid;      /* 1 -> pack_id input to read(), 0 -> ignored */
 165         char cmd_q;             /* 1 -> allow command queuing, 0 -> don't */
 166         unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
 167         char keep_orphan;       /* 0 -> drop orphan (def), 1 -> keep for read() */
 168         char mmap_called;       /* 0 -> mmap() never called on this fd */
 169         struct kref f_ref;
 170         struct execute_work ew;
 171 } Sg_fd;
 172
 173 typedef struct sg_device { /* holds the state of each scsi generic device */
 174         struct scsi_device *device;
 175         wait_queue_head_t open_wait;    /* queue open() when O_EXCL present */
 176         struct mutex open_rel_lock;     /* held when in open() or release() */
 177         int sg_tablesize;       /* adapter's max scatter-gather table size */
 178         u32 index;              /* device index number */
 179         struct list_head sfds;
 180         rwlock_t sfd_lock;      /* protect access to sfd list */
 181         atomic_t detaching;     /* 0->device usable, 1->device detaching */
 182         bool exclude;           /* 1->open(O_EXCL) succeeded and is active */
 183         int open_cnt;           /* count of opens (perhaps < num(sfds) ) */
 184         char sgdebug;           /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
 185         struct gendisk *disk;
 186         struct cdev * cdev;     /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
 187         struct kref d_ref;
 188 } Sg_device;
 189
 190 /* tasklet or soft irq callback */
 191 static void sg_rq_end_io(struct request *rq, int uptodate);
 192 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 193 static int sg_finish_rem_req(Sg_request * srp);
 194 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 195 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
 196                            Sg_request * srp);
 197 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 198                         const char __user *buf, size_t count, int blocking,
 199                         int read_only, int sg_io_owned, Sg_request **o_srp);
 200 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 201                            unsigned char *cmnd, int timeout, int blocking);
 202 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 203 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
 204 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 205 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 206 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
 207 static Sg_fd *sg_add_sfp(Sg_device * sdp);
 208 static void sg_remove_sfp(struct kref *);
 209 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 210 static Sg_request *sg_add_request(Sg_fd * sfp);
 211 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 212 static int sg_res_in_use(Sg_fd * sfp);
 213 static Sg_device *sg_get_dev(int dev);
 214 static void sg_device_destroy(struct kref *kref);
 215
 216 #define SZ_SG_HEADER sizeof(struct sg_header)
 217 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
 218 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
 219 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
 220
 221 #define sg_printk(prefix, sdp, fmt, a...) \
 222         sdev_prefix_printk(prefix, (sdp)->device,               \
 223                            (sdp)->disk->disk_name, fmt, ##a)
 224
 225 static int sg_allow_access(struct file *filp, unsigned char *cmd)
 226 {
 227         struct sg_fd *sfp = filp->private_data;
 228
 229         if (sfp->parentdp->device->type == TYPE_SCANNER)
 230                 return 0;
 231
 232         return blk_verify_command(cmd, filp->f_mode & FMODE_WRITE);
 233 }
 234
 235 static int
 236 open_wait(Sg_device *sdp, int flags)
 237 {
 238         int retval = 0;
 239
 240         if (flags & O_EXCL) {
 241                 while (sdp->open_cnt > 0) {
 242                         mutex_unlock(&sdp->open_rel_lock);
 243                         retval = wait_event_interruptible(sdp->open_wait,
 244                                         (atomic_read(&sdp->detaching) ||
 245                                          !sdp->open_cnt));
 246                         mutex_lock(&sdp->open_rel_lock);
 247
 248                         if (retval) /* -ERESTARTSYS */
 249                                 return retval;
 250                         if (atomic_read(&sdp->detaching))
 251                                 return -ENODEV;
 252                 }
 253         } else {
 254                 while (sdp->exclude) {
 255                         mutex_unlock(&sdp->open_rel_lock);
 256                         retval = wait_event_interruptible(sdp->open_wait,
 257                                         (atomic_read(&sdp->detaching) ||
 258                                          !sdp->exclude));
 259                         mutex_lock(&sdp->open_rel_lock);
 260
 261                         if (retval) /* -ERESTARTSYS */
 262                                 return retval;
 263                         if (atomic_read(&sdp->detaching))
 264                                 return -ENODEV;
 265                 }
 266         }
 267
 268         return retval;
 269 }
 270
 271 /* Returns 0 on success, else a negated errno value */
 272 static int
 273 sg_open(struct inode *inode, struct file *filp)
 274 {
 275         int dev = iminor(inode);
 276         int flags = filp->f_flags;
 277         struct request_queue *q;
 278         Sg_device *sdp;
 279         Sg_fd *sfp;
 280         int retval;
 281
 282         nonseekable_open(inode, filp);
 283         if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
 284                 return -EPERM; /* Can't lock it with read only access */
 285         sdp = sg_get_dev(dev);
 286         if (IS_ERR(sdp))
 287                 return PTR_ERR(sdp);
 288
 289         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 290                                       "sg_open: flags=0x%x\n", flags));
 291
 292         /* This driver's module count bumped by fops_get in <linux/fs.h> */
 293         /* Prevent the device driver from vanishing while we sleep */
 294         retval = scsi_device_get(sdp->device);
 295         if (retval)
 296                 goto sg_put;
 297
 298         retval = scsi_autopm_get_device(sdp->device);
 299         if (retval)
 300                 goto sdp_put;
 301
 302         /* scsi_block_when_processing_errors() may block so bypass
 303          * check if O_NONBLOCK. Permits SCSI commands to be issued
 304          * during error recovery. Tread carefully. */
 305         if (!((flags & O_NONBLOCK) ||
 306               scsi_block_when_processing_errors(sdp->device))) {
 307                 retval = -ENXIO;
 308                 /* we are in error recovery for this device */
 309                 goto error_out;
 310         }
 311
 312         mutex_lock(&sdp->open_rel_lock);
 313         if (flags & O_NONBLOCK) {
 314                 if (flags & O_EXCL) {
 315                         if (sdp->open_cnt > 0) {
 316                                 retval = -EBUSY;
 317                                 goto error_mutex_locked;
 318                         }
 319                 } else {
 320                         if (sdp->exclude) {
 321                                 retval = -EBUSY;
 322                                 goto error_mutex_locked;
 323                         }
 324                 }
 325         } else {
 326                 retval = open_wait(sdp, flags);
 327                 if (retval) /* -ERESTARTSYS or -ENODEV */
 328                         goto error_mutex_locked;
 329         }
 330
 331         /* N.B. at this point we are holding the open_rel_lock */
 332         if (flags & O_EXCL)
 333                 sdp->exclude = true;
 334
 335         if (sdp->open_cnt < 1) {  /* no existing opens */
 336                 sdp->sgdebug = 0;
 337                 q = sdp->device->request_queue;
 338                 sdp->sg_tablesize = queue_max_segments(q);
 339         }
 340         sfp = sg_add_sfp(sdp);
 341         if (IS_ERR(sfp)) {
 342                 retval = PTR_ERR(sfp);
 343                 goto out_undo;
 344         }
 345
 346         filp->private_data = sfp;
 347         sdp->open_cnt++;
 348         mutex_unlock(&sdp->open_rel_lock);
 349
 350         retval = 0;
 351 sg_put:
 352         kref_put(&sdp->d_ref, sg_device_destroy);
 353         return retval;
 354
 355 out_undo:
 356         if (flags & O_EXCL) {
 357                 sdp->exclude = false;   /* undo if error */
 358                 wake_up_interruptible(&sdp->open_wait);
 359         }
 360 error_mutex_locked:
 361         mutex_unlock(&sdp->open_rel_lock);
 362 error_out:
 363         scsi_autopm_put_device(sdp->device);
 364 sdp_put:
 365         scsi_device_put(sdp->device);
 366         goto sg_put;
 367 }
 368
 369 /* Release resources associated with a successful sg_open()
 370  * Returns 0 on success, else a negated errno value */
 371 static int
 372 sg_release(struct inode *inode, struct file *filp)
 373 {
 374         Sg_device *sdp;
 375         Sg_fd *sfp;
 376
 377         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 378                 return -ENXIO;
 379         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
 380
 381         mutex_lock(&sdp->open_rel_lock);
 382         scsi_autopm_put_device(sdp->device);
 383         kref_put(&sfp->f_ref, sg_remove_sfp);
 384         sdp->open_cnt--;
 385
 386         /* possibly many open()s waiting on exlude clearing, start many;
 387          * only open(O_EXCL)s wait on 0==open_cnt so only start one */
 388         if (sdp->exclude) {
 389                 sdp->exclude = false;
 390                 wake_up_interruptible_all(&sdp->open_wait);
 391         } else if (0 == sdp->open_cnt) {
 392                 wake_up_interruptible(&sdp->open_wait);
 393         }
 394         mutex_unlock(&sdp->open_rel_lock);
 395         return 0;
 396 }
 397
 398 static ssize_t
 399 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
 400 {
 401         Sg_device *sdp;
 402         Sg_fd *sfp;
 403         Sg_request *srp;
 404         int req_pack_id = -1;
 405         sg_io_hdr_t *hp;
 406         struct sg_header *old_hdr = NULL;
 407         int retval = 0;
 408
 409         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 410                 return -ENXIO;
 411         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 412                                       "sg_read: count=%d\n", (int) count));
 413
 414         if (!access_ok(VERIFY_WRITE, buf, count))
 415                 return -EFAULT;
 416         if (sfp->force_packid && (count >= SZ_SG_HEADER)) {
 417                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 418                 if (!old_hdr)
 419                         return -ENOMEM;
 420                 if (__copy_from_user(old_hdr, buf, SZ_SG_HEADER)) {
 421                         retval = -EFAULT;
 422                         goto free_old_hdr;
 423                 }
 424                 if (old_hdr->reply_len < 0) {
 425                         if (count >= SZ_SG_IO_HDR) {
 426                                 sg_io_hdr_t *new_hdr;
 427                                 new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
 428                                 if (!new_hdr) {
 429                                         retval = -ENOMEM;
 430                                         goto free_old_hdr;
 431                                 }
 432                                 retval =__copy_from_user
 433                                     (new_hdr, buf, SZ_SG_IO_HDR);
 434                                 req_pack_id = new_hdr->pack_id;
 435                                 kfree(new_hdr);
 436                                 if (retval) {
 437                                         retval = -EFAULT;
 438                                         goto free_old_hdr;
 439                                 }
 440                         }
 441                 } else
 442                         req_pack_id = old_hdr->pack_id;
 443         }
 444         srp = sg_get_rq_mark(sfp, req_pack_id);
 445         if (!srp) {             /* now wait on packet to arrive */
 446                 if (atomic_read(&sdp->detaching)) {
 447                         retval = -ENODEV;
 448                         goto free_old_hdr;
 449                 }
 450                 if (filp->f_flags & O_NONBLOCK) {
 451                         retval = -EAGAIN;
 452                         goto free_old_hdr;
 453                 }
 454                 retval = wait_event_interruptible(sfp->read_wait,
 455                         (atomic_read(&sdp->detaching) ||
 456                         (srp = sg_get_rq_mark(sfp, req_pack_id))));
 457                 if (atomic_read(&sdp->detaching)) {
 458                         retval = -ENODEV;
 459                         goto free_old_hdr;
 460                 }
 461                 if (retval) {
 462                         /* -ERESTARTSYS as signal hit process */
 463                         goto free_old_hdr;
 464                 }
 465         }
 466         if (srp->header.interface_id != '\0') {
 467                 retval = sg_new_read(sfp, buf, count, srp);
 468                 goto free_old_hdr;
 469         }
 470
 471         hp = &srp->header;
 472         if (old_hdr == NULL) {
 473                 old_hdr = kmalloc(SZ_SG_HEADER, GFP_KERNEL);
 474                 if (! old_hdr) {
 475                         retval = -ENOMEM;
 476                         goto free_old_hdr;
 477                 }
 478         }
 479         memset(old_hdr, 0, SZ_SG_HEADER);
 480         old_hdr->reply_len = (int) hp->timeout;
 481         old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
 482         old_hdr->pack_id = hp->pack_id;
 483         old_hdr->twelve_byte =
 484             ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
 485         old_hdr->target_status = hp->masked_status;
 486         old_hdr->host_status = hp->host_status;
 487         old_hdr->driver_status = hp->driver_status;
 488         if ((CHECK_CONDITION & hp->masked_status) ||
 489             (DRIVER_SENSE & hp->driver_status))
 490                 memcpy(old_hdr->sense_buffer, srp->sense_b,
 491                        sizeof (old_hdr->sense_buffer));
 492         switch (hp->host_status) {
 493         /* This setup of 'result' is for backward compatibility and is best
 494            ignored by the user who should use target, host + driver status */
 495         case DID_OK:
 496         case DID_PASSTHROUGH:
 497         case DID_SOFT_ERROR:
 498                 old_hdr->result = 0;
 499                 break;
 500         case DID_NO_CONNECT:
 501         case DID_BUS_BUSY:
 502         case DID_TIME_OUT:
 503                 old_hdr->result = EBUSY;
 504                 break;
 505         case DID_BAD_TARGET:
 506         case DID_ABORT:
 507         case DID_PARITY:
 508         case DID_RESET:
 509         case DID_BAD_INTR:
 510                 old_hdr->result = EIO;
 511                 break;
 512         case DID_ERROR:
 513                 old_hdr->result = (srp->sense_b[0] == 0 &&
 514                                   hp->masked_status == GOOD) ? 0 : EIO;
 515                 break;
 516         default:
 517                 old_hdr->result = EIO;
 518                 break;
 519         }
 520
 521         /* Now copy the result back to the user buffer.  */
 522         if (count >= SZ_SG_HEADER) {
 523                 if (__copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
 524                         retval = -EFAULT;
 525                         goto free_old_hdr;
 526                 }
 527                 buf += SZ_SG_HEADER;
 528                 if (count > old_hdr->reply_len)
 529                         count = old_hdr->reply_len;
 530                 if (count > SZ_SG_HEADER) {
 531                         if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
 532                                 retval = -EFAULT;
 533                                 goto free_old_hdr;
 534                         }
 535                 }
 536         } else
 537                 count = (old_hdr->result == 0) ? 0 : -EIO;
 538         sg_finish_rem_req(srp);
 539         retval = count;
 540 free_old_hdr:
 541         kfree(old_hdr);
 542         return retval;
 543 }
 544
 545 static ssize_t
 546 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 547 {
 548         sg_io_hdr_t *hp = &srp->header;
 549         int err = 0;
 550         int len;
 551
 552         if (count < SZ_SG_IO_HDR) {
 553                 err = -EINVAL;
 554                 goto err_out;
 555         }
 556         hp->sb_len_wr = 0;
 557         if ((hp->mx_sb_len > 0) && hp->sbp) {
 558                 if ((CHECK_CONDITION & hp->masked_status) ||
 559                     (DRIVER_SENSE & hp->driver_status)) {
 560                         int sb_len = SCSI_SENSE_BUFFERSIZE;
 561                         sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
 562                         len = 8 + (int) srp->sense_b[7];        /* Additional sense length field */
 563                         len = (len > sb_len) ? sb_len : len;
 564                         if (copy_to_user(hp->sbp, srp->sense_b, len)) {
 565                                 err = -EFAULT;
 566                                 goto err_out;
 567                         }
 568                         hp->sb_len_wr = len;
 569                 }
 570         }
 571         if (hp->masked_status || hp->host_status || hp->driver_status)
 572                 hp->info |= SG_INFO_CHECK;
 573         if (copy_to_user(buf, hp, SZ_SG_IO_HDR)) {
 574                 err = -EFAULT;
 575                 goto err_out;
 576         }
 577 err_out:
 578         err = sg_finish_rem_req(srp);
 579         return (0 == err) ? count : err;
 580 }
 581
 582 static ssize_t
 583 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 584 {
 585         int mxsize, cmd_size, k;
 586         int input_size, blocking;
 587         unsigned char opcode;
 588         Sg_device *sdp;
 589         Sg_fd *sfp;
 590         Sg_request *srp;
 591         struct sg_header old_hdr;
 592         sg_io_hdr_t *hp;
 593         unsigned char cmnd[SG_MAX_CDB_SIZE];
 594
 595         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 596                 return -ENXIO;
 597         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 598                                       "sg_write: count=%d\n", (int) count));
 599         if (atomic_read(&sdp->detaching))
 600                 return -ENODEV;
 601         if (!((filp->f_flags & O_NONBLOCK) ||
 602               scsi_block_when_processing_errors(sdp->device)))
 603                 return -ENXIO;
 604
 605         if (!access_ok(VERIFY_READ, buf, count))
 606                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 607         if (count < SZ_SG_HEADER)
 608                 return -EIO;
 609         if (__copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
 610                 return -EFAULT;
 611         blocking = !(filp->f_flags & O_NONBLOCK);
 612         if (old_hdr.reply_len < 0)
 613                 return sg_new_write(sfp, filp, buf, count,
 614                                     blocking, 0, 0, NULL);
 615         if (count < (SZ_SG_HEADER + 6))
 616                 return -EIO;    /* The minimum scsi command length is 6 bytes. */
 617
 618         if (!(srp = sg_add_request(sfp))) {
 619                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
 620                                               "sg_write: queue full\n"));
 621                 return -EDOM;
 622         }
 623         buf += SZ_SG_HEADER;
 624         __get_user(opcode, buf);
 625         if (sfp->next_cmd_len > 0) {
 626                 cmd_size = sfp->next_cmd_len;
 627                 sfp->next_cmd_len = 0;  /* reset so only this write() effected */
 628         } else {
 629                 cmd_size = COMMAND_SIZE(opcode);        /* based on SCSI command group */
 630                 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
 631                         cmd_size = 12;
 632         }
 633         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
 634                 "sg_write:   scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
 635 /* Determine buffer size.  */
 636         input_size = count - cmd_size;
 637         mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
 638         mxsize -= SZ_SG_HEADER;
 639         input_size -= SZ_SG_HEADER;
 640         if (input_size < 0) {
 641                 sg_remove_request(sfp, srp);
 642                 return -EIO;    /* User did not pass enough bytes for this command. */
 643         }
 644         hp = &srp->header;
 645         hp->interface_id = '\0';        /* indicator of old interface tunnelled */
 646         hp->cmd_len = (unsigned char) cmd_size;
 647         hp->iovec_count = 0;
 648         hp->mx_sb_len = 0;
 649         if (input_size > 0)
 650                 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
 651                     SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
 652         else
 653                 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 654         hp->dxfer_len = mxsize;
 655         if (hp->dxfer_direction == SG_DXFER_TO_DEV)
 656                 hp->dxferp = (char __user *)buf + cmd_size;
 657         else
 658                 hp->dxferp = NULL;
 659         hp->sbp = NULL;
 660         hp->timeout = old_hdr.reply_len;        /* structure abuse ... */
 661         hp->flags = input_size; /* structure abuse ... */
 662         hp->pack_id = old_hdr.pack_id;
 663         hp->usr_ptr = NULL;
 664         if (__copy_from_user(cmnd, buf, cmd_size))
 665                 return -EFAULT;
 666         /*
 667          * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 668          * but is is possible that the app intended SG_DXFER_TO_DEV, because there
 669          * is a non-zero input_size, so emit a warning.
 670          */
 671         if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
 672                 static char cmd[TASK_COMM_LEN];
 673                 if (strcmp(current->comm, cmd)) {
 674                         printk_ratelimited(KERN_WARNING
 675                                            "sg_write: data in/out %d/%d bytes "
 676                                            "for SCSI command 0x%x-- guessing "
 677                                            "data in;\n   program %s not setting "
 678                                            "count and/or reply_len properly\n",
 679                                            old_hdr.reply_len - (int)SZ_SG_HEADER,
 680                                            input_size, (unsigned int) cmnd[0],
 681                                            current->comm);
 682                         strcpy(cmd, current->comm);
 683                 }
 684         }
 685         k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
 686         return (k < 0) ? k : count;
 687 }
 688
 689 static ssize_t
 690 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
 691                  size_t count, int blocking, int read_only, int sg_io_owned,
 692                  Sg_request **o_srp)
 693 {
 694         int k;
 695         Sg_request *srp;
 696         sg_io_hdr_t *hp;
 697         unsigned char cmnd[SG_MAX_CDB_SIZE];
 698         int timeout;
 699         unsigned long ul_timeout;
 700
 701         if (count < SZ_SG_IO_HDR)
 702                 return -EINVAL;
 703         if (!access_ok(VERIFY_READ, buf, count))
 704                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 705
 706         sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
 707         if (!(srp = sg_add_request(sfp))) {
 708                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 709                                               "sg_new_write: queue full\n"));
 710                 return -EDOM;
 711         }
 712         srp->sg_io_owned = sg_io_owned;
 713         hp = &srp->header;
 714         if (__copy_from_user(hp, buf, SZ_SG_IO_HDR)) {
 715                 sg_remove_request(sfp, srp);
 716                 return -EFAULT;
 717         }
 718         if (hp->interface_id != 'S') {
 719                 sg_remove_request(sfp, srp);
 720                 return -ENOSYS;
 721         }
 722         if (hp->flags & SG_FLAG_MMAP_IO) {
 723                 if (hp->dxfer_len > sfp->reserve.bufflen) {
 724                         sg_remove_request(sfp, srp);
 725                         return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
 726                 }
 727                 if (hp->flags & SG_FLAG_DIRECT_IO) {
 728                         sg_remove_request(sfp, srp);
 729                         return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
 730                 }
 731                 if (sg_res_in_use(sfp)) {
 732                         sg_remove_request(sfp, srp);
 733                         return -EBUSY;  /* reserve buffer already being used */
 734                 }
 735         }
 736         ul_timeout = msecs_to_jiffies(srp->header.timeout);
 737         timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
 738         if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
 739                 sg_remove_request(sfp, srp);
 740                 return -EMSGSIZE;
 741         }
 742         if (!access_ok(VERIFY_READ, hp->cmdp, hp->cmd_len)) {
 743                 sg_remove_request(sfp, srp);
 744                 return -EFAULT; /* protects following copy_from_user()s + get_user()s */
 745         }
 746         if (__copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
 747                 sg_remove_request(sfp, srp);
 748                 return -EFAULT;
 749         }
 750         if (read_only && sg_allow_access(file, cmnd)) {
 751                 sg_remove_request(sfp, srp);
 752                 return -EPERM;
 753         }
 754         k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
 755         if (k < 0)
 756                 return k;
 757         if (o_srp)
 758                 *o_srp = srp;
 759         return count;
 760 }
 761
 762 static int
 763 sg_common_write(Sg_fd * sfp, Sg_request * srp,
 764                 unsigned char *cmnd, int timeout, int blocking)
 765 {
 766         int k, data_dir, at_head;
 767         Sg_device *sdp = sfp->parentdp;
 768         sg_io_hdr_t *hp = &srp->header;
 769
 770         srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
 771         hp->status = 0;
 772         hp->masked_status = 0;
 773         hp->msg_status = 0;
 774         hp->info = 0;
 775         hp->host_status = 0;
 776         hp->driver_status = 0;
 777         hp->resid = 0;
 778         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
 779                         "sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 780                         (int) cmnd[0], (int) hp->cmd_len));
 781
 782         k = sg_start_req(srp, cmnd);
 783         if (k) {
 784                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
 785                         "sg_common_write: start_req err=%d\n", k));
 786                 sg_finish_rem_req(srp);
 787                 return k;       /* probably out of space --> ENOMEM */
 788         }
 789         if (atomic_read(&sdp->detaching)) {
 790                 if (srp->bio)
 791                         blk_end_request_all(srp->rq, -EIO);
 792                 sg_finish_rem_req(srp);
 793                 return -ENODEV;
 794         }
 795
 796         switch (hp->dxfer_direction) {
 797         case SG_DXFER_TO_FROM_DEV:
 798         case SG_DXFER_FROM_DEV:
 799                 data_dir = DMA_FROM_DEVICE;
 800                 break;
 801         case SG_DXFER_TO_DEV:
 802                 data_dir = DMA_TO_DEVICE;
 803                 break;
 804         case SG_DXFER_UNKNOWN:
 805                 data_dir = DMA_BIDIRECTIONAL;
 806                 break;
 807         default:
 808                 data_dir = DMA_NONE;
 809                 break;
 810         }
 811         hp->duration = jiffies_to_msecs(jiffies);
 812         if (hp->interface_id != '\0' && /* v3 (or later) interface */
 813             (SG_FLAG_Q_AT_TAIL & hp->flags))
 814                 at_head = 0;
 815         else
 816                 at_head = 1;
 817
 818         srp->rq->timeout = timeout;
 819         kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
 820         blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
 821                               srp->rq, at_head, sg_rq_end_io);
 822         return 0;
 823 }
 824
 825 static int srp_done(Sg_fd *sfp, Sg_request *srp)
 826 {
 827         unsigned long flags;
 828         int ret;
 829
 830         read_lock_irqsave(&sfp->rq_list_lock, flags);
 831         ret = srp->done;
 832         read_unlock_irqrestore(&sfp->rq_list_lock, flags);
 833         return ret;
 834 }
 835
 836 static int max_sectors_bytes(struct request_queue *q)
 837 {
 838         unsigned int max_sectors = queue_max_sectors(q);
 839
 840         max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
 841
 842         return max_sectors << 9;
 843 }
 844
 845 static long
 846 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 847 {
 848         void __user *p = (void __user *)arg;
 849         int __user *ip = p;
 850         int result, val, read_only;
 851         Sg_device *sdp;
 852         Sg_fd *sfp;
 853         Sg_request *srp;
 854         unsigned long iflags;
 855
 856         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 857                 return -ENXIO;
 858
 859         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 860                                    "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 861         read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
 862
 863         switch (cmd_in) {
 864         case SG_IO:
 865                 if (atomic_read(&sdp->detaching))
 866                         return -ENODEV;
 867                 if (!scsi_block_when_processing_errors(sdp->device))
 868                         return -ENXIO;
 869                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_IO_HDR))
 870                         return -EFAULT;
 871                 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
 872                                  1, read_only, 1, &srp);
 873                 if (result < 0)
 874                         return result;
 875                 result = wait_event_interruptible(sfp->read_wait,
 876                         (srp_done(sfp, srp) || atomic_read(&sdp->detaching)));
 877                 if (atomic_read(&sdp->detaching))
 878                         return -ENODEV;
 879                 write_lock_irq(&sfp->rq_list_lock);
 880                 if (srp->done) {
 881                         srp->done = 2;
 882                         write_unlock_irq(&sfp->rq_list_lock);
 883                         result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
 884                         return (result < 0) ? result : 0;
 885                 }
 886                 srp->orphan = 1;
 887                 write_unlock_irq(&sfp->rq_list_lock);
 888                 return result;  /* -ERESTARTSYS because signal hit process */
 889         case SG_SET_TIMEOUT:
 890                 result = get_user(val, ip);
 891                 if (result)
 892                         return result;
 893                 if (val < 0)
 894                         return -EIO;
 895                 if (val >= MULDIV (INT_MAX, USER_HZ, HZ))
 896                     val = MULDIV (INT_MAX, USER_HZ, HZ);
 897                 sfp->timeout_user = val;
 898                 sfp->timeout = MULDIV (val, HZ, USER_HZ);
 899
 900                 return 0;
 901         case SG_GET_TIMEOUT:    /* N.B. User receives timeout as return value */
 902                                 /* strange ..., for backward compatibility */
 903                 return sfp->timeout_user;
 904         case SG_SET_FORCE_LOW_DMA:
 905                 result = get_user(val, ip);
 906                 if (result)
 907                         return result;
 908                 if (val) {
 909                         sfp->low_dma = 1;
 910                         if ((0 == sfp->low_dma) && (0 == sg_res_in_use(sfp))) {
 911                                 val = (int) sfp->reserve.bufflen;
 912                                 sg_remove_scat(sfp, &sfp->reserve);
 913                                 sg_build_reserve(sfp, val);
 914                         }
 915                 } else {
 916                         if (atomic_read(&sdp->detaching))
 917                                 return -ENODEV;
 918                         sfp->low_dma = sdp->device->host->unchecked_isa_dma;
 919                 }
 920                 return 0;
 921         case SG_GET_LOW_DMA:
 922                 return put_user((int) sfp->low_dma, ip);
 923         case SG_GET_SCSI_ID:
 924                 if (!access_ok(VERIFY_WRITE, p, sizeof (sg_scsi_id_t)))
 925                         return -EFAULT;
 926                 else {
 927                         sg_scsi_id_t __user *sg_idp = p;
 928
 929                         if (atomic_read(&sdp->detaching))
 930                                 return -ENODEV;
 931                         __put_user((int) sdp->device->host->host_no,
 932                                    &sg_idp->host_no);
 933                         __put_user((int) sdp->device->channel,
 934                                    &sg_idp->channel);
 935                         __put_user((int) sdp->device->id, &sg_idp->scsi_id);
 936                         __put_user((int) sdp->device->lun, &sg_idp->lun);
 937                         __put_user((int) sdp->device->type, &sg_idp->scsi_type);
 938                         __put_user((short) sdp->device->host->cmd_per_lun,
 939                                    &sg_idp->h_cmd_per_lun);
 940                         __put_user((short) sdp->device->queue_depth,
 941                                    &sg_idp->d_queue_depth);
 942                         __put_user(0, &sg_idp->unused[0]);
 943                         __put_user(0, &sg_idp->unused[1]);
 944                         return 0;
 945                 }
 946         case SG_SET_FORCE_PACK_ID:
 947                 result = get_user(val, ip);
 948                 if (result)
 949                         return result;
 950                 sfp->force_packid = val ? 1 : 0;
 951                 return 0;
 952         case SG_GET_PACK_ID:
 953                 if (!access_ok(VERIFY_WRITE, ip, sizeof (int)))
 954                         return -EFAULT;
 955                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 956                 for (srp = sfp->headrp; srp; srp = srp->nextrp) {
 957                         if ((1 == srp->done) && (!srp->sg_io_owned)) {
 958                                 read_unlock_irqrestore(&sfp->rq_list_lock,
 959                                                        iflags);
 960                                 __put_user(srp->header.pack_id, ip);
 961                                 return 0;
 962                         }
 963                 }
 964                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 965                 __put_user(-1, ip);
 966                 return 0;
 967         case SG_GET_NUM_WAITING:
 968                 read_lock_irqsave(&sfp->rq_list_lock, iflags);
 969                 for (val = 0, srp = sfp->headrp; srp; srp = srp->nextrp) {
 970                         if ((1 == srp->done) && (!srp->sg_io_owned))
 971                                 ++val;
 972                 }
 973                 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
 974                 return put_user(val, ip);
 975         case SG_GET_SG_TABLESIZE:
 976                 return put_user(sdp->sg_tablesize, ip);
 977         case SG_SET_RESERVED_SIZE:
 978                 result = get_user(val, ip);
 979                 if (result)
 980                         return result;
 981                 if (val < 0)
 982                         return -EINVAL;
 983                 val = min_t(int, val,
 984                             max_sectors_bytes(sdp->device->request_queue));
 985                 if (val != sfp->reserve.bufflen) {
 986                         if (sg_res_in_use(sfp) || sfp->mmap_called)
 987                                 return -EBUSY;
 988                         sg_remove_scat(sfp, &sfp->reserve);
 989                         sg_build_reserve(sfp, val);
 990                 }
 991                 return 0;
 992         case SG_GET_RESERVED_SIZE:
 993                 val = min_t(int, sfp->reserve.bufflen,
 994                             max_sectors_bytes(sdp->device->request_queue));
 995                 return put_user(val, ip);
 996         case SG_SET_COMMAND_Q:
 997                 result = get_user(val, ip);
 998                 if (result)
 999                         return result;
1000                 sfp->cmd_q = val ? 1 : 0;
1001                 return 0;
1002         case SG_GET_COMMAND_Q:
1003                 return put_user((int) sfp->cmd_q, ip);
1004         case SG_SET_KEEP_ORPHAN:
1005                 result = get_user(val, ip);
1006                 if (result)
1007                         return result;
1008                 sfp->keep_orphan = val;
1009                 return 0;
1010         case SG_GET_KEEP_ORPHAN:
1011                 return put_user((int) sfp->keep_orphan, ip);
1012         case SG_NEXT_CMD_LEN:
1013                 result = get_user(val, ip);
1014                 if (result)
1015                         return result;
1016                 sfp->next_cmd_len = (val > 0) ? val : 0;
1017                 return 0;
1018         case SG_GET_VERSION_NUM:
1019                 return put_user(sg_version_num, ip);
1020         case SG_GET_ACCESS_COUNT:
1021                 /* faked - we don't have a real access count anymore */
1022                 val = (sdp->device ? 1 : 0);
1023                 return put_user(val, ip);
1024         case SG_GET_REQUEST_TABLE:
1025                 if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
1026                         return -EFAULT;
1027                 else {
1028                         sg_req_info_t *rinfo;
1029                         unsigned int ms;
1030
1031                         rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
1032                                                                 GFP_KERNEL);
1033                         if (!rinfo)
1034                                 return -ENOMEM;
1035                         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1036                         for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
1037                              ++val, srp = srp ? srp->nextrp : srp) {
1038                                 memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
1039                                 if (srp) {
1040                                         rinfo[val].req_state = srp->done + 1;
1041                                         rinfo[val].problem =
1042                                             srp->header.masked_status &
1043                                             srp->header.host_status &
1044                                             srp->header.driver_status;
1045                                         if (srp->done)
1046                                                 rinfo[val].duration =
1047                                                         srp->header.duration;
1048                                         else {
1049                                                 ms = jiffies_to_msecs(jiffies);
1050                                                 rinfo[val].duration =
1051                                                     (ms > srp->header.duration) ?
1052                                                     (ms - srp->header.duration) : 0;
1053                                         }
1054                                         rinfo[val].orphan = srp->orphan;
1055                                         rinfo[val].sg_io_owned =
1056                                                         srp->sg_io_owned;
1057                                         rinfo[val].pack_id =
1058                                                         srp->header.pack_id;
1059                                         rinfo[val].usr_ptr =
1060                                                         srp->header.usr_ptr;
1061                                 }
1062                         }
1063                         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1064                         result = __copy_to_user(p, rinfo,
1065                                                 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1066                         result = result ? -EFAULT : 0;
1067                         kfree(rinfo);
1068                         return result;
1069                 }
1070         case SG_EMULATED_HOST:
1071                 if (atomic_read(&sdp->detaching))
1072                         return -ENODEV;
1073                 return put_user(sdp->device->host->hostt->emulated, ip);
1074         case SCSI_IOCTL_SEND_COMMAND:
1075                 if (atomic_read(&sdp->detaching))
1076                         return -ENODEV;
1077                 if (read_only) {
1078                         unsigned char opcode = WRITE_6;
1079                         Scsi_Ioctl_Command __user *siocp = p;
1080
1081                         if (copy_from_user(&opcode, siocp->data, 1))
1082                                 return -EFAULT;
1083                         if (sg_allow_access(filp, &opcode))
1084                                 return -EPERM;
1085                 }
1086                 return sg_scsi_ioctl(sdp->device->request_queue, NULL, filp->f_mode, p);
1087         case SG_SET_DEBUG:
1088                 result = get_user(val, ip);
1089                 if (result)
1090                         return result;
1091                 sdp->sgdebug = (char) val;
1092                 return 0;
1093         case BLKSECTGET:
1094                 return put_user(max_sectors_bytes(sdp->device->request_queue),
1095                                 ip);
1096         case BLKTRACESETUP:
1097                 return blk_trace_setup(sdp->device->request_queue,
1098                                        sdp->disk->disk_name,
1099                                        MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1100                                        NULL,
1101                                        (char *)arg);
1102         case BLKTRACESTART:
1103                 return blk_trace_startstop(sdp->device->request_queue, 1);
1104         case BLKTRACESTOP:
1105                 return blk_trace_startstop(sdp->device->request_queue, 0);
1106         case BLKTRACETEARDOWN:
1107                 return blk_trace_remove(sdp->device->request_queue);
1108         case SCSI_IOCTL_GET_IDLUN:
1109         case SCSI_IOCTL_GET_BUS_NUMBER:
1110         case SCSI_IOCTL_PROBE_HOST:
1111         case SG_GET_TRANSFORM:
1112         case SG_SCSI_RESET:
1113                 if (atomic_read(&sdp->detaching))
1114                         return -ENODEV;
1115                 break;
1116         default:
1117                 if (read_only)
1118                         return -EPERM;  /* don't know so take safe approach */
1119                 break;
1120         }
1121
1122         result = scsi_ioctl_block_when_processing_errors(sdp->device,
1123                         cmd_in, filp->f_flags & O_NDELAY);
1124         if (result)
1125                 return result;
1126         return scsi_ioctl(sdp->device, cmd_in, p);
1127 }
1128
1129 #ifdef CONFIG_COMPAT
1130 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1131 {
1132         Sg_device *sdp;
1133         Sg_fd *sfp;
1134         struct scsi_device *sdev;
1135
1136         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1137                 return -ENXIO;
1138
1139         sdev = sdp->device;
1140         if (sdev->host->hostt->compat_ioctl) {
1141                 int ret;
1142
1143                 ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);
1144
1145                 return ret;
1146         }
1147
1148         return -ENOIOCTLCMD;
1149 }
1150 #endif
1151
1152 static unsigned int
1153 sg_poll(struct file *filp, poll_table * wait)
1154 {
1155         unsigned int res = 0;
1156         Sg_device *sdp;
1157         Sg_fd *sfp;
1158         Sg_request *srp;
1159         int count = 0;
1160         unsigned long iflags;
1161
1162         sfp = filp->private_data;
1163         if (!sfp)
1164                 return POLLERR;
1165         sdp = sfp->parentdp;
1166         if (!sdp)
1167                 return POLLERR;
1168         poll_wait(filp, &sfp->read_wait, wait);
1169         read_lock_irqsave(&sfp->rq_list_lock, iflags);
1170         for (srp = sfp->headrp; srp; srp = srp->nextrp) {
1171                 /* if any read waiting, flag it */
1172                 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1173                         res = POLLIN | POLLRDNORM;
1174                 ++count;
1175         }
1176         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1177
1178         if (atomic_read(&sdp->detaching))
1179                 res |= POLLHUP;
1180         else if (!sfp->cmd_q) {
1181                 if (0 == count)
1182                         res |= POLLOUT | POLLWRNORM;
1183         } else if (count < SG_MAX_QUEUE)
1184                 res |= POLLOUT | POLLWRNORM;
1185         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1186                                       "sg_poll: res=0x%x\n", (int) res));
1187         return res;
1188 }
1189
1190 static int
1191 sg_fasync(int fd, struct file *filp, int mode)
1192 {
1193         Sg_device *sdp;
1194         Sg_fd *sfp;
1195
1196         if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1197                 return -ENXIO;
1198         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1199                                       "sg_fasync: mode=%d\n", mode));
1200
1201         return fasync_helper(fd, filp, mode, &sfp->async_qp);
1202 }
1203
1204 static int
1205 sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1206 {
1207         Sg_fd *sfp;
1208         unsigned long offset, len, sa;
1209         Sg_scatter_hold *rsv_schp;
1210         int k, length;
1211
1212         if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1213                 return VM_FAULT_SIGBUS;
1214         rsv_schp = &sfp->reserve;
1215         offset = vmf->pgoff << PAGE_SHIFT;
1216         if (offset >= rsv_schp->bufflen)
1217                 return VM_FAULT_SIGBUS;
1218         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1219                                       "sg_vma_fault: offset=%lu, scatg=%d\n",
1220                                       offset, rsv_schp->k_use_sg));
1221         sa = vma->vm_start;
1222         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1223         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1224                 len = vma->vm_end - sa;
1225                 len = (len < length) ? len : length;
1226                 if (offset < len) {
1227                         struct page *page = nth_page(rsv_schp->pages[k],
1228                                                      offset >> PAGE_SHIFT);
1229                         get_page(page); /* increment page count */
1230                         vmf->page = page;
1231                         return 0; /* success */
1232                 }
1233                 sa += len;
1234                 offset -= len;
1235         }
1236
1237         return VM_FAULT_SIGBUS;
1238 }
1239
1240 static const struct vm_operations_struct sg_mmap_vm_ops = {
1241         .fault = sg_vma_fault,
1242 };
1243
1244 static int
1245 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1246 {
1247         Sg_fd *sfp;
1248         unsigned long req_sz, len, sa;
1249         Sg_scatter_hold *rsv_schp;
1250         int k, length;
1251
1252         if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1253                 return -ENXIO;
1254         req_sz = vma->vm_end - vma->vm_start;
1255         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1256                                       "sg_mmap starting, vm_start=%p, len=%d\n",
1257                                       (void *) vma->vm_start, (int) req_sz));
1258         if (vma->vm_pgoff)
1259                 return -EINVAL; /* want no offset */
1260         rsv_schp = &sfp->reserve;
1261         if (req_sz > rsv_schp->bufflen)
1262                 return -ENOMEM; /* cannot map more than reserved buffer */
1263
1264         sa = vma->vm_start;
1265         length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1266         for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1267                 len = vma->vm_end - sa;
1268                 len = (len < length) ? len : length;
1269                 sa += len;
1270         }
1271
1272         sfp->mmap_called = 1;
1273         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
1274         vma->vm_private_data = sfp;
1275         vma->vm_ops = &sg_mmap_vm_ops;
1276         return 0;
1277 }
1278
1279 static void
1280 sg_rq_end_io_usercontext(struct work_struct *work)
1281 {
1282         struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1283         struct sg_fd *sfp = srp->parentfp;
1284
1285         sg_finish_rem_req(srp);
1286         kref_put(&sfp->f_ref, sg_remove_sfp);
1287 }
1288
1289 /*
1290  * This function is a "bottom half" handler that is called by the mid
1291  * level when a command is completed (or has failed).
1292  */
1293 static void
1294 sg_rq_end_io(struct request *rq, int uptodate)
1295 {
1296         struct sg_request *srp = rq->end_io_data;
1297         Sg_device *sdp;
1298         Sg_fd *sfp;
1299         unsigned long iflags;
1300         unsigned int ms;
1301         char *sense;
1302         int result, resid, done = 1;
1303
1304         if (WARN_ON(srp->done != 0))
1305                 return;
1306
1307         sfp = srp->parentfp;
1308         if (WARN_ON(sfp == NULL))
1309                 return;
1310
1311         sdp = sfp->parentdp;
1312         if (unlikely(atomic_read(&sdp->detaching)))
1313                 pr_info("%s: device detaching\n", __func__);
1314
1315         sense = rq->sense;
1316         result = rq->errors;
1317         resid = rq->resid_len;
1318
1319         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1320                                       "sg_cmd_done: pack_id=%d, res=0x%x\n",
1321                                       srp->header.pack_id, result));
1322         srp->header.resid = resid;
1323         ms = jiffies_to_msecs(jiffies);
1324         srp->header.duration = (ms > srp->header.duration) ?
1325                                 (ms - srp->header.duration) : 0;
1326         if (0 != result) {
1327                 struct scsi_sense_hdr sshdr;
1328
1329                 srp->header.status = 0xff & result;
1330                 srp->header.masked_status = status_byte(result);
1331                 srp->header.msg_status = msg_byte(result);
1332                 srp->header.host_status = host_byte(result);
1333                 srp->header.driver_status = driver_byte(result);
1334                 if ((sdp->sgdebug > 0) &&
1335                     ((CHECK_CONDITION == srp->header.masked_status) ||
1336                      (COMMAND_TERMINATED == srp->header.masked_status)))
1337                         __scsi_print_sense(sdp->device, __func__, sense,
1338                                            SCSI_SENSE_BUFFERSIZE);
1339
1340                 /* Following if statement is a patch supplied by Eric Youngdale */
1341                 if (driver_byte(result) != 0
1342                     && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1343                     && !scsi_sense_is_deferred(&sshdr)
1344                     && sshdr.sense_key == UNIT_ATTENTION
1345                     && sdp->device->removable) {
1346                         /* Detected possible disc change. Set the bit - this */
1347                         /* may be used if there are filesystems using this device */
1348                         sdp->device->changed = 1;
1349                 }
1350         }
1351         /* Rely on write phase to clean out srp status values, so no "else" */
1352
1353         write_lock_irqsave(&sfp->rq_list_lock, iflags);
1354         if (unlikely(srp->orphan)) {
1355                 if (sfp->keep_orphan)
1356                         srp->sg_io_owned = 0;
1357                 else
1358                         done = 0;
1359         }
1360         srp->done = done;
1361         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1362
1363         if (likely(done)) {
1364                 /* Now wake up any sg_read() that is waiting for this
1365                  * packet.
1366                  */
1367                 wake_up_interruptible(&sfp->read_wait);
1368                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1369                 kref_put(&sfp->f_ref, sg_remove_sfp);
1370         } else {
1371                 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1372                 schedule_work(&srp->ew.work);
1373         }
1374 }
1375
1376 static const struct file_operations sg_fops = {
1377         .owner = THIS_MODULE,
1378         .read = sg_read,
1379         .write = sg_write,
1380         .poll = sg_poll,
1381         .unlocked_ioctl = sg_ioctl,
1382 #ifdef CONFIG_COMPAT
1383         .compat_ioctl = sg_compat_ioctl,
1384 #endif
1385         .open = sg_open,
1386         .mmap = sg_mmap,
1387         .release = sg_release,
1388         .fasync = sg_fasync,
1389         .llseek = no_llseek,
1390 };
1391
1392 static struct class *sg_sysfs_class;
1393
1394 static int sg_sysfs_valid = 0;
1395
1396 static Sg_device *
1397 sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
1398 {
1399         struct request_queue *q = scsidp->request_queue;
1400         Sg_device *sdp;
1401         unsigned long iflags;
1402         int error;
1403         u32 k;
1404
1405         sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1406         if (!sdp) {
1407                 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1408                             "failure\n", __func__);
1409                 return ERR_PTR(-ENOMEM);
1410         }
1411
1412         idr_preload(GFP_KERNEL);
1413         write_lock_irqsave(&sg_index_lock, iflags);
1414
1415         error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1416         if (error < 0) {
1417                 if (error == -ENOSPC) {
1418                         sdev_printk(KERN_WARNING, scsidp,
1419                                     "Unable to attach sg device type=%d, minor number exceeds %d\n",
1420                                     scsidp->type, SG_MAX_DEVS - 1);
1421                         error = -ENODEV;
1422                 } else {
1423                         sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1424                                     "allocation Sg_device failure: %d\n",
1425                                     __func__, error);
1426                 }
1427                 goto out_unlock;
1428         }
1429         k = error;
1430
1431         SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1432                                         "sg_alloc: dev=%d \n", k));
1433         sprintf(disk->disk_name, "sg%d", k);
1434         disk->first_minor = k;
1435         sdp->disk = disk;
1436         sdp->device = scsidp;
1437         mutex_init(&sdp->open_rel_lock);
1438         INIT_LIST_HEAD(&sdp->sfds);
1439         init_waitqueue_head(&sdp->open_wait);
1440         atomic_set(&sdp->detaching, 0);
1441         rwlock_init(&sdp->sfd_lock);
1442         sdp->sg_tablesize = queue_max_segments(q);
1443         sdp->index = k;
1444         kref_init(&sdp->d_ref);
1445         error = 0;
1446
1447 out_unlock:
1448         write_unlock_irqrestore(&sg_index_lock, iflags);
1449         idr_preload_end();
1450
1451         if (error) {
1452                 kfree(sdp);
1453                 return ERR_PTR(error);
1454         }
1455         return sdp;
1456 }
1457
1458 static int
1459 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1460 {
1461         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1462         struct gendisk *disk;
1463         Sg_device *sdp = NULL;
1464         struct cdev * cdev = NULL;
1465         int error;
1466         unsigned long iflags;
1467
1468         disk = alloc_disk(1);
1469         if (!disk) {
1470                 pr_warn("%s: alloc_disk failed\n", __func__);
1471                 return -ENOMEM;
1472         }
1473         disk->major = SCSI_GENERIC_MAJOR;
1474
1475         error = -ENOMEM;
1476         cdev = cdev_alloc();
1477         if (!cdev) {
1478                 pr_warn("%s: cdev_alloc failed\n", __func__);
1479                 goto out;
1480         }
1481         cdev->owner = THIS_MODULE;
1482         cdev->ops = &sg_fops;
1483
1484         sdp = sg_alloc(disk, scsidp);
1485         if (IS_ERR(sdp)) {
1486                 pr_warn("%s: sg_alloc failed\n", __func__);
1487                 error = PTR_ERR(sdp);
1488                 goto out;
1489         }
1490
1491         error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1492         if (error)
1493                 goto cdev_add_err;
1494
1495         sdp->cdev = cdev;
1496         if (sg_sysfs_valid) {
1497                 struct device *sg_class_member;
1498
1499                 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1500                                                 MKDEV(SCSI_GENERIC_MAJOR,
1501                                                       sdp->index),
1502                                                 sdp, "%s", disk->disk_name);
1503                 if (IS_ERR(sg_class_member)) {
1504                         pr_err("%s: device_create failed\n", __func__);
1505                         error = PTR_ERR(sg_class_member);
1506                         goto cdev_add_err;
1507                 }
1508                 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1509                                           &sg_class_member->kobj, "generic");
1510                 if (error)
1511                         pr_err("%s: unable to make symlink 'generic' back "
1512                                "to sg%d\n", __func__, sdp->index);
1513         } else
1514                 pr_warn("%s: sg_sys Invalid\n", __func__);
1515
1516         sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1517                     "type %d\n", sdp->index, scsidp->type);
1518
1519         dev_set_drvdata(cl_dev, sdp);
1520
1521         return 0;
1522
1523 cdev_add_err:
1524         write_lock_irqsave(&sg_index_lock, iflags);
1525         idr_remove(&sg_index_idr, sdp->index);
1526         write_unlock_irqrestore(&sg_index_lock, iflags);
1527         kfree(sdp);
1528
1529 out:
1530         put_disk(disk);
1531         if (cdev)
1532                 cdev_del(cdev);
1533         return error;
1534 }
1535
1536 static void
1537 sg_device_destroy(struct kref *kref)
1538 {
1539         struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1540         unsigned long flags;
1541
1542         /* CAUTION!  Note that the device can still be found via idr_find()
1543          * even though the refcount is 0.  Therefore, do idr_remove() BEFORE
1544          * any other cleanup.
1545          */
1546
1547         write_lock_irqsave(&sg_index_lock, flags);
1548         idr_remove(&sg_index_idr, sdp->index);
1549         write_unlock_irqrestore(&sg_index_lock, flags);
1550
1551         SCSI_LOG_TIMEOUT(3,
1552                 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1553
1554         put_disk(sdp->disk);
1555         kfree(sdp);
1556 }
1557
1558 static void
1559 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1560 {
1561         struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1562         Sg_device *sdp = dev_get_drvdata(cl_dev);
1563         unsigned long iflags;
1564         Sg_fd *sfp;
1565         int val;
1566
1567         if (!sdp)
1568                 return;
1569         /* want sdp->detaching non-zero as soon as possible */
1570         val = atomic_inc_return(&sdp->detaching);
1571         if (val > 1)
1572                 return; /* only want to do following once per device */
1573
1574         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1575                                       "%s\n", __func__));
1576
1577         read_lock_irqsave(&sdp->sfd_lock, iflags);
1578         list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1579                 wake_up_interruptible_all(&sfp->read_wait);
1580                 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1581         }
1582         wake_up_interruptible_all(&sdp->open_wait);
1583         read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1584
1585         sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1586         device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1587         cdev_del(sdp->cdev);
1588         sdp->cdev = NULL;
1589
1590         kref_put(&sdp->d_ref, sg_device_destroy);
1591 }
1592
1593 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1594 module_param_named(def_reserved_size, def_reserved_size, int,
1595                    S_IRUGO | S_IWUSR);
1596 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1597
1598 MODULE_AUTHOR("Douglas Gilbert");
1599 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1600 MODULE_LICENSE("GPL");
1601 MODULE_VERSION(SG_VERSION_STR);
1602 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1603
1604 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1605                 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1606 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1607 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1608
1609 static int __init
1610 init_sg(void)
1611 {
1612         int rc;
1613
1614         if (scatter_elem_sz < PAGE_SIZE) {
1615                 scatter_elem_sz = PAGE_SIZE;
1616                 scatter_elem_sz_prev = scatter_elem_sz;
1617         }
1618         if (def_reserved_size >= 0)
1619                 sg_big_buff = def_reserved_size;
1620         else
1621                 def_reserved_size = sg_big_buff;
1622
1623         rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1624                                     SG_MAX_DEVS, "sg");
1625         if (rc)
1626                 return rc;
1627         sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1628         if ( IS_ERR(sg_sysfs_class) ) {
1629                 rc = PTR_ERR(sg_sysfs_class);
1630                 goto err_out;
1631         }
1632         sg_sysfs_valid = 1;
1633         rc = scsi_register_interface(&sg_interface);
1634         if (0 == rc) {
1635 #ifdef CONFIG_SCSI_PROC_FS
1636                 sg_proc_init();
1637 #endif                          /* CONFIG_SCSI_PROC_FS */
1638                 return 0;
1639         }
1640         class_destroy(sg_sysfs_class);
1641 err_out:
1642         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1643         return rc;
1644 }
1645
1646 static void __exit
1647 exit_sg(void)
1648 {
1649 #ifdef CONFIG_SCSI_PROC_FS
1650         sg_proc_cleanup();
1651 #endif                          /* CONFIG_SCSI_PROC_FS */
1652         scsi_unregister_interface(&sg_interface);
1653         class_destroy(sg_sysfs_class);
1654         sg_sysfs_valid = 0;
1655         unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1656                                  SG_MAX_DEVS);
1657         idr_destroy(&sg_index_idr);
1658 }
1659
1660 static int
1661 sg_start_req(Sg_request *srp, unsigned char *cmd)
1662 {
1663         int res;
1664         struct request *rq;
1665         Sg_fd *sfp = srp->parentfp;
1666         sg_io_hdr_t *hp = &srp->header;
1667         int dxfer_len = (int) hp->dxfer_len;
1668         int dxfer_dir = hp->dxfer_direction;
1669         unsigned int iov_count = hp->iovec_count;
1670         Sg_scatter_hold *req_schp = &srp->data;
1671         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1672         struct request_queue *q = sfp->parentdp->device->request_queue;
1673         struct rq_map_data *md, map_data;
1674         int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1675         unsigned char *long_cmdp = NULL;
1676
1677         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1678                                       "sg_start_req: dxfer_len=%d\n",
1679                                       dxfer_len));
1680
1681         if (hp->cmd_len > BLK_MAX_CDB) {
1682                 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1683                 if (!long_cmdp)
1684                         return -ENOMEM;
1685         }
1686
1687         rq = blk_get_request(q, rw, GFP_ATOMIC);
1688         if (IS_ERR(rq)) {
1689                 kfree(long_cmdp);
1690                 return PTR_ERR(rq);
1691         }
1692
1693         blk_rq_set_block_pc(rq);
1694
1695         if (hp->cmd_len > BLK_MAX_CDB)
1696                 rq->cmd = long_cmdp;
1697         memcpy(rq->cmd, cmd, hp->cmd_len);
1698         rq->cmd_len = hp->cmd_len;
1699
1700         srp->rq = rq;
1701         rq->end_io_data = srp;
1702         rq->sense = srp->sense_b;
1703         rq->retries = SG_DEFAULT_RETRIES;
1704
1705         if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1706                 return 0;
1707
1708         if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1709             dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1710             !sfp->parentdp->device->host->unchecked_isa_dma &&
1711             blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1712                 md = NULL;
1713         else
1714                 md = &map_data;
1715
1716         if (md) {
1717                 if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
1718                         sg_link_reserve(sfp, srp, dxfer_len);
1719                 else {
1720                         res = sg_build_indirect(req_schp, sfp, dxfer_len);
1721                         if (res)
1722                                 return res;
1723                 }
1724
1725                 md->pages = req_schp->pages;
1726                 md->page_order = req_schp->page_order;
1727                 md->nr_entries = req_schp->k_use_sg;
1728                 md->offset = 0;
1729                 md->null_mapped = hp->dxferp ? 0 : 1;
1730                 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1731                         md->from_user = 1;
1732                 else
1733                         md->from_user = 0;
1734         }
1735
1736         if (iov_count) {
1737                 int len, size = sizeof(struct sg_iovec) * iov_count;
1738                 struct iovec *iov;
1739
1740                 iov = memdup_user(hp->dxferp, size);
1741                 if (IS_ERR(iov))
1742                         return PTR_ERR(iov);
1743
1744                 len = iov_length(iov, iov_count);
1745                 if (hp->dxfer_len < len) {
1746                         iov_count = iov_shorten(iov, iov_count, hp->dxfer_len);
1747                         len = hp->dxfer_len;
1748                 }
1749
1750                 res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov,
1751                                           iov_count,
1752                                           len, GFP_ATOMIC);
1753                 kfree(iov);
1754         } else
1755                 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1756                                       hp->dxfer_len, GFP_ATOMIC);
1757
1758         if (!res) {
1759                 srp->bio = rq->bio;
1760
1761                 if (!md) {
1762                         req_schp->dio_in_use = 1;
1763                         hp->info |= SG_INFO_DIRECT_IO;
1764                 }
1765         }
1766         return res;
1767 }
1768
1769 static int
1770 sg_finish_rem_req(Sg_request *srp)
1771 {
1772         int ret = 0;
1773
1774         Sg_fd *sfp = srp->parentfp;
1775         Sg_scatter_hold *req_schp = &srp->data;
1776
1777         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1778                                       "sg_finish_rem_req: res_used=%d\n",
1779                                       (int) srp->res_used));
1780         if (srp->rq) {
1781                 if (srp->bio)
1782                         ret = blk_rq_unmap_user(srp->bio);
1783
1784                 if (srp->rq->cmd != srp->rq->__cmd)
1785                         kfree(srp->rq->cmd);
1786                 blk_put_request(srp->rq);
1787         }
1788
1789         if (srp->res_used)
1790                 sg_unlink_reserve(sfp, srp);
1791         else
1792                 sg_remove_scat(sfp, req_schp);
1793
1794         sg_remove_request(sfp, srp);
1795
1796         return ret;
1797 }
1798
1799 static int
1800 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1801 {
1802         int sg_bufflen = tablesize * sizeof(struct page *);
1803         gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1804
1805         schp->pages = kzalloc(sg_bufflen, gfp_flags);
1806         if (!schp->pages)
1807                 return -ENOMEM;
1808         schp->sglist_len = sg_bufflen;
1809         return tablesize;       /* number of scat_gath elements allocated */
1810 }
1811
1812 static int
1813 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1814 {
1815         int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1816         int sg_tablesize = sfp->parentdp->sg_tablesize;
1817         int blk_size = buff_size, order;
1818         gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
1819
1820         if (blk_size < 0)
1821                 return -EFAULT;
1822         if (0 == blk_size)
1823                 ++blk_size;     /* don't know why */
1824         /* round request up to next highest SG_SECTOR_SZ byte boundary */
1825         blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1826         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1827                 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1828                 buff_size, blk_size));
1829
1830         /* N.B. ret_sz carried into this block ... */
1831         mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1832         if (mx_sc_elems < 0)
1833                 return mx_sc_elems;     /* most likely -ENOMEM */
1834
1835         num = scatter_elem_sz;
1836         if (unlikely(num != scatter_elem_sz_prev)) {
1837                 if (num < PAGE_SIZE) {
1838                         scatter_elem_sz = PAGE_SIZE;
1839                         scatter_elem_sz_prev = PAGE_SIZE;
1840                 } else
1841                         scatter_elem_sz_prev = num;
1842         }
1843
1844         if (sfp->low_dma)
1845                 gfp_mask |= GFP_DMA;
1846
1847         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
1848                 gfp_mask |= __GFP_ZERO;
1849
1850         order = get_order(num);
1851 retry:
1852         ret_sz = 1 << (PAGE_SHIFT + order);
1853
1854         for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1855              k++, rem_sz -= ret_sz) {
1856
1857                 num = (rem_sz > scatter_elem_sz_prev) ?
1858                         scatter_elem_sz_prev : rem_sz;
1859
1860                 schp->pages[k] = alloc_pages(gfp_mask, order);
1861                 if (!schp->pages[k])
1862                         goto out;
1863
1864                 if (num == scatter_elem_sz_prev) {
1865                         if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1866                                 scatter_elem_sz = ret_sz;
1867                                 scatter_elem_sz_prev = ret_sz;
1868                         }
1869                 }
1870
1871                 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1872                                  "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1873                                  k, num, ret_sz));
1874         }               /* end of for loop */
1875
1876         schp->page_order = order;
1877         schp->k_use_sg = k;
1878         SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1879                          "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1880                          k, rem_sz));
1881
1882         schp->bufflen = blk_size;
1883         if (rem_sz > 0) /* must have failed */
1884                 return -ENOMEM;
1885         return 0;
1886 out:
1887         for (i = 0; i < k; i++)
1888                 __free_pages(schp->pages[i], order);
1889
1890         if (--order >= 0)
1891                 goto retry;
1892
1893         return -ENOMEM;
1894 }
1895
1896 static void
1897 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1898 {
1899         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1900                          "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1901         if (schp->pages && schp->sglist_len > 0) {
1902                 if (!schp->dio_in_use) {
1903                         int k;
1904
1905                         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1906                                 SCSI_LOG_TIMEOUT(5,
1907                                         sg_printk(KERN_INFO, sfp->parentdp,
1908                                         "sg_remove_scat: k=%d, pg=0x%p\n",
1909                                         k, schp->pages[k]));
1910                                 __free_pages(schp->pages[k], schp->page_order);
1911                         }
1912
1913                         kfree(schp->pages);
1914                 }
1915         }
1916         memset(schp, 0, sizeof (*schp));
1917 }
1918
1919 static int
1920 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1921 {
1922         Sg_scatter_hold *schp = &srp->data;
1923         int k, num;
1924
1925         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1926                          "sg_read_oxfer: num_read_xfer=%d\n",
1927                          num_read_xfer));
1928         if ((!outp) || (num_read_xfer <= 0))
1929                 return 0;
1930
1931         num = 1 << (PAGE_SHIFT + schp->page_order);
1932         for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1933                 if (num > num_read_xfer) {
1934                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1935                                            num_read_xfer))
1936                                 return -EFAULT;
1937                         break;
1938                 } else {
1939                         if (__copy_to_user(outp, page_address(schp->pages[k]),
1940                                            num))
1941                                 return -EFAULT;
1942                         num_read_xfer -= num;
1943                         if (num_read_xfer <= 0)
1944                                 break;
1945                         outp += num;
1946                 }
1947         }
1948
1949         return 0;
1950 }
1951
1952 static void
1953 sg_build_reserve(Sg_fd * sfp, int req_size)
1954 {
1955         Sg_scatter_hold *schp = &sfp->reserve;
1956
1957         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1958                          "sg_build_reserve: req_size=%d\n", req_size));
1959         do {
1960                 if (req_size < PAGE_SIZE)
1961                         req_size = PAGE_SIZE;
1962                 if (0 == sg_build_indirect(schp, sfp, req_size))
1963                         return;
1964                 else
1965                         sg_remove_scat(sfp, schp);
1966                 req_size >>= 1; /* divide by 2 */
1967         } while (req_size > (PAGE_SIZE / 2));
1968 }
1969
1970 static void
1971 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
1972 {
1973         Sg_scatter_hold *req_schp = &srp->data;
1974         Sg_scatter_hold *rsv_schp = &sfp->reserve;
1975         int k, num, rem;
1976
1977         srp->res_used = 1;
1978         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1979                          "sg_link_reserve: size=%d\n", size));
1980         rem = size;
1981
1982         num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1983         for (k = 0; k < rsv_schp->k_use_sg; k++) {
1984                 if (rem <= num) {
1985                         req_schp->k_use_sg = k + 1;
1986                         req_schp->sglist_len = rsv_schp->sglist_len;
1987                         req_schp->pages = rsv_schp->pages;
1988
1989                         req_schp->bufflen = size;
1990                         req_schp->page_order = rsv_schp->page_order;
1991                         break;
1992                 } else
1993                         rem -= num;
1994         }
1995
1996         if (k >= rsv_schp->k_use_sg)
1997                 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
1998                                  "sg_link_reserve: BAD size\n"));
1999 }
2000
2001 static void
2002 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2003 {
2004         Sg_scatter_hold *req_schp = &srp->data;
2005
2006         SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2007                                       "sg_unlink_reserve: req->k_use_sg=%d\n",
2008                                       (int) req_schp->k_use_sg));
2009         req_schp->k_use_sg = 0;
2010         req_schp->bufflen = 0;
2011         req_schp->pages = NULL;
2012         req_schp->page_order = 0;
2013         req_schp->sglist_len = 0;
2014         sfp->save_scat_len = 0;
2015         srp->res_used = 0;
2016 }
2017
2018 static Sg_request *
2019 sg_get_rq_mark(Sg_fd * sfp, int pack_id)
2020 {
2021         Sg_request *resp;
2022         unsigned long iflags;
2023
2024         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2025         for (resp = sfp->headrp; resp; resp = resp->nextrp) {
2026                 /* look for requests that are ready + not SG_IO owned */
2027                 if ((1 == resp->done) && (!resp->sg_io_owned) &&
2028                     ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2029                         resp->done = 2; /* guard against other readers */
2030                         break;
2031                 }
2032         }
2033         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2034         return resp;
2035 }
2036
2037 /* always adds to end of list */
2038 static Sg_request *
2039 sg_add_request(Sg_fd * sfp)
2040 {
2041         int k;
2042         unsigned long iflags;
2043         Sg_request *resp;
2044         Sg_request *rp = sfp->req_arr;
2045
2046         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2047         resp = sfp->headrp;
2048         if (!resp) {
2049                 memset(rp, 0, sizeof (Sg_request));
2050                 rp->parentfp = sfp;
2051                 resp = rp;
2052                 sfp->headrp = resp;
2053         } else {
2054                 if (0 == sfp->cmd_q)
2055                         resp = NULL;    /* command queuing disallowed */
2056                 else {
2057                         for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2058                                 if (!rp->parentfp)
2059                                         break;
2060                         }
2061                         if (k < SG_MAX_QUEUE) {
2062                                 memset(rp, 0, sizeof (Sg_request));
2063                                 rp->parentfp = sfp;
2064                                 while (resp->nextrp)
2065                                         resp = resp->nextrp;
2066                                 resp->nextrp = rp;
2067                                 resp = rp;
2068                         } else
2069                                 resp = NULL;
2070                 }
2071         }
2072         if (resp) {
2073                 resp->nextrp = NULL;
2074                 resp->header.duration = jiffies_to_msecs(jiffies);
2075         }
2076         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2077         return resp;
2078 }
2079
2080 /* Return of 1 for found; 0 for not found */
2081 static int
2082 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2083 {
2084         Sg_request *prev_rp;
2085         Sg_request *rp;
2086         unsigned long iflags;
2087         int res = 0;
2088
2089         if ((!sfp) || (!srp) || (!sfp->headrp))
2090                 return res;
2091         write_lock_irqsave(&sfp->rq_list_lock, iflags);
2092         prev_rp = sfp->headrp;
2093         if (srp == prev_rp) {
2094                 sfp->headrp = prev_rp->nextrp;
2095                 prev_rp->parentfp = NULL;
2096                 res = 1;
2097         } else {
2098                 while ((rp = prev_rp->nextrp)) {
2099                         if (srp == rp) {
2100                                 prev_rp->nextrp = rp->nextrp;
2101                                 rp->parentfp = NULL;
2102                                 res = 1;
2103                                 break;
2104                         }
2105                         prev_rp = rp;
2106                 }
2107         }
2108         write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2109         return res;
2110 }
2111
2112 static Sg_fd *
2113 sg_add_sfp(Sg_device * sdp)
2114 {
2115         Sg_fd *sfp;
2116         unsigned long iflags;
2117         int bufflen;
2118
2119         sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2120         if (!sfp)
2121                 return ERR_PTR(-ENOMEM);
2122
2123         init_waitqueue_head(&sfp->read_wait);
2124         rwlock_init(&sfp->rq_list_lock);
2125
2126         kref_init(&sfp->f_ref);
2127         sfp->timeout = SG_DEFAULT_TIMEOUT;
2128         sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2129         sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2130         sfp->low_dma = (SG_DEF_FORCE_LOW_DMA == 0) ?
2131             sdp->device->host->unchecked_isa_dma : 1;
2132         sfp->cmd_q = SG_DEF_COMMAND_Q;
2133         sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2134         sfp->parentdp = sdp;
2135         write_lock_irqsave(&sdp->sfd_lock, iflags);
2136         if (atomic_read(&sdp->detaching)) {
2137                 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2138                 return ERR_PTR(-ENODEV);
2139         }
2140         list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2141         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2142         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2143                                       "sg_add_sfp: sfp=0x%p\n", sfp));
2144         if (unlikely(sg_big_buff != def_reserved_size))
2145                 sg_big_buff = def_reserved_size;
2146
2147         bufflen = min_t(int, sg_big_buff,
2148                         max_sectors_bytes(sdp->device->request_queue));
2149         sg_build_reserve(sfp, bufflen);
2150         SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2151                                       "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2152                                       sfp->reserve.bufflen,
2153                                       sfp->reserve.k_use_sg));
2154
2155         kref_get(&sdp->d_ref);
2156         __module_get(THIS_MODULE);
2157         return sfp;
2158 }
2159
2160 static void
2161 sg_remove_sfp_usercontext(struct work_struct *work)
2162 {
2163         struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2164         struct sg_device *sdp = sfp->parentdp;
2165
2166         /* Cleanup any responses which were never read(). */
2167         while (sfp->headrp)
2168                 sg_finish_rem_req(sfp->headrp);
2169
2170         if (sfp->reserve.bufflen > 0) {
2171                 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2172                                 "sg_remove_sfp:    bufflen=%d, k_use_sg=%d\n",
2173                                 (int) sfp->reserve.bufflen,
2174                                 (int) sfp->reserve.k_use_sg));
2175                 sg_remove_scat(sfp, &sfp->reserve);
2176         }
2177
2178         SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2179                         "sg_remove_sfp: sfp=0x%p\n", sfp));
2180         kfree(sfp);
2181
2182         scsi_device_put(sdp->device);
2183         kref_put(&sdp->d_ref, sg_device_destroy);
2184         module_put(THIS_MODULE);
2185 }
2186
2187 static void
2188 sg_remove_sfp(struct kref *kref)
2189 {
2190         struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2191         struct sg_device *sdp = sfp->parentdp;
2192         unsigned long iflags;
2193
2194         write_lock_irqsave(&sdp->sfd_lock, iflags);
2195         list_del(&sfp->sfd_siblings);
2196         write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2197
2198         INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2199         schedule_work(&sfp->ew.work);
2200 }
2201
2202 static int
2203 sg_res_in_use(Sg_fd * sfp)
2204 {
2205         const Sg_request *srp;
2206         unsigned long iflags;
2207
2208         read_lock_irqsave(&sfp->rq_list_lock, iflags);
2209         for (srp = sfp->headrp; srp; srp = srp->nextrp)
2210                 if (srp->res_used)
2211                         break;
2212         read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2213         return srp ? 1 : 0;
2214 }
2215
2216 #ifdef CONFIG_SCSI_PROC_FS
2217 static int
2218 sg_idr_max_id(int id, void *p, void *data)
2219 {
2220         int *k = data;
2221
2222         if (*k < id)
2223                 *k = id;
2224
2225         return 0;
2226 }
2227
2228 static int
2229 sg_last_dev(void)
2230 {
2231         int k = -1;
2232         unsigned long iflags;
2233
2234         read_lock_irqsave(&sg_index_lock, iflags);
2235         idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2236         read_unlock_irqrestore(&sg_index_lock, iflags);
2237         return k + 1;           /* origin 1 */
2238 }
2239 #endif
2240
2241 /* must be called with sg_index_lock held */
2242 static Sg_device *sg_lookup_dev(int dev)
2243 {
2244         return idr_find(&sg_index_idr, dev);
2245 }
2246
2247 static Sg_device *
2248 sg_get_dev(int dev)
2249 {
2250         struct sg_device *sdp;
2251         unsigned long flags;
2252
2253         read_lock_irqsave(&sg_index_lock, flags);
2254         sdp = sg_lookup_dev(dev);
2255         if (!sdp)
2256                 sdp = ERR_PTR(-ENXIO);
2257         else if (atomic_read(&sdp->detaching)) {
2258                 /* If sdp->detaching, then the refcount may already be 0, in
2259                  * which case it would be a bug to do kref_get().
2260                  */
2261                 sdp = ERR_PTR(-ENODEV);
2262         } else
2263                 kref_get(&sdp->d_ref);
2264         read_unlock_irqrestore(&sg_index_lock, flags);
2265
2266         return sdp;
2267 }
2268
2269 #ifdef CONFIG_SCSI_PROC_FS
2270
2271 static struct proc_dir_entry *sg_proc_sgp = NULL;
2272
2273 static char sg_proc_sg_dirname[] = "scsi/sg";
2274
2275 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2276
2277 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2278 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2279                                   size_t count, loff_t *off);
2280 static const struct file_operations adio_fops = {
2281         .owner = THIS_MODULE,
2282         .open = sg_proc_single_open_adio,
2283         .read = seq_read,
2284         .llseek = seq_lseek,
2285         .write = sg_proc_write_adio,
2286         .release = single_release,
2287 };
2288
2289 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2290 static ssize_t sg_proc_write_dressz(struct file *filp,
2291                 const char __user *buffer, size_t count, loff_t *off);
2292 static const struct file_operations dressz_fops = {
2293         .owner = THIS_MODULE,
2294         .open = sg_proc_single_open_dressz,
2295         .read = seq_read,
2296         .llseek = seq_lseek,
2297         .write = sg_proc_write_dressz,
2298         .release = single_release,
2299 };
2300
2301 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2302 static int sg_proc_single_open_version(struct inode *inode, struct file *file);
2303 static const struct file_operations version_fops = {
2304         .owner = THIS_MODULE,
2305         .open = sg_proc_single_open_version,
2306         .read = seq_read,
2307         .llseek = seq_lseek,
2308         .release = single_release,
2309 };
2310
2311 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2312 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file);
2313 static const struct file_operations devhdr_fops = {
2314         .owner = THIS_MODULE,
2315         .open = sg_proc_single_open_devhdr,
2316         .read = seq_read,
2317         .llseek = seq_lseek,
2318         .release = single_release,
2319 };
2320
2321 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2322 static int sg_proc_open_dev(struct inode *inode, struct file *file);
2323 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2324 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2325 static void dev_seq_stop(struct seq_file *s, void *v);
2326 static const struct file_operations dev_fops = {
2327         .owner = THIS_MODULE,
2328         .open = sg_proc_open_dev,
2329         .read = seq_read,
2330         .llseek = seq_lseek,
2331         .release = seq_release,
2332 };
2333 static const struct seq_operations dev_seq_ops = {
2334         .start = dev_seq_start,
2335         .next  = dev_seq_next,
2336         .stop  = dev_seq_stop,
2337         .show  = sg_proc_seq_show_dev,
2338 };
2339
2340 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2341 static int sg_proc_open_devstrs(struct inode *inode, struct file *file);
2342 static const struct file_operations devstrs_fops = {
2343         .owner = THIS_MODULE,
2344         .open = sg_proc_open_devstrs,
2345         .read = seq_read,
2346         .llseek = seq_lseek,
2347         .release = seq_release,
2348 };
2349 static const struct seq_operations devstrs_seq_ops = {
2350         .start = dev_seq_start,
2351         .next  = dev_seq_next,
2352         .stop  = dev_seq_stop,
2353         .show  = sg_proc_seq_show_devstrs,
2354 };
2355
2356 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2357 static int sg_proc_open_debug(struct inode *inode, struct file *file);
2358 static const struct file_operations debug_fops = {
2359         .owner = THIS_MODULE,
2360         .open = sg_proc_open_debug,
2361         .read = seq_read,
2362         .llseek = seq_lseek,
2363         .release = seq_release,
2364 };
2365 static const struct seq_operations debug_seq_ops = {
2366         .start = dev_seq_start,
2367         .next  = dev_seq_next,
2368         .stop  = dev_seq_stop,
2369         .show  = sg_proc_seq_show_debug,
2370 };
2371
2372
2373 struct sg_proc_leaf {
2374         const char * name;
2375         const struct file_operations * fops;
2376 };
2377
2378 static const struct sg_proc_leaf sg_proc_leaf_arr[] = {
2379         {"allow_dio", &adio_fops},
2380         {"debug", &debug_fops},
2381         {"def_reserved_size", &dressz_fops},
2382         {"device_hdr", &devhdr_fops},
2383         {"devices", &dev_fops},
2384         {"device_strs", &devstrs_fops},
2385         {"version", &version_fops}
2386 };
2387
2388 static int
2389 sg_proc_init(void)
2390 {
2391         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2392         int k;
2393
2394         sg_proc_sgp = proc_mkdir(sg_proc_sg_dirname, NULL);
2395         if (!sg_proc_sgp)
2396                 return 1;
2397         for (k = 0; k < num_leaves; ++k) {
2398                 const struct sg_proc_leaf *leaf = &sg_proc_leaf_arr[k];
2399                 umode_t mask = leaf->fops->write ? S_IRUGO | S_IWUSR : S_IRUGO;
2400                 proc_create(leaf->name, mask, sg_proc_sgp, leaf->fops);
2401         }
2402         return 0;
2403 }
2404
2405 static void
2406 sg_proc_cleanup(void)
2407 {
2408         int k;
2409         int num_leaves = ARRAY_SIZE(sg_proc_leaf_arr);
2410
2411         if (!sg_proc_sgp)
2412                 return;
2413         for (k = 0; k < num_leaves; ++k)
2414                 remove_proc_entry(sg_proc_leaf_arr[k].name, sg_proc_sgp);
2415         remove_proc_entry(sg_proc_sg_dirname, NULL);
2416 }
2417
2418
2419 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2420 {
2421         seq_printf(s, "%d\n", *((int *)s->private));
2422         return 0;
2423 }
2424
2425 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2426 {
2427         return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2428 }
2429
2430 static ssize_t
2431 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2432                    size_t count, loff_t *off)
2433 {
2434         int err;
2435         unsigned long num;
2436
2437         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2438                 return -EACCES;
2439         err = kstrtoul_from_user(buffer, count, 0, &num);
2440         if (err)
2441                 return err;
2442         sg_allow_dio = num ? 1 : 0;
2443         return count;
2444 }
2445
2446 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2447 {
2448         return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2449 }
2450
2451 static ssize_t
2452 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2453                      size_t count, loff_t *off)
2454 {
2455         int err;
2456         unsigned long k = ULONG_MAX;
2457
2458         if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2459                 return -EACCES;
2460
2461         err = kstrtoul_from_user(buffer, count, 0, &k);
2462         if (err)
2463                 return err;
2464         if (k <= 1048576) {     /* limit "big buff" to 1 MB */
2465                 sg_big_buff = k;
2466                 return count;
2467         }
2468         return -ERANGE;
2469 }
2470
2471 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2472 {
2473         seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2474                    sg_version_date);
2475         return 0;
2476 }
2477
2478 static int sg_proc_single_open_version(struct inode *inode, struct file *file)
2479 {
2480         return single_open(file, sg_proc_seq_show_version, NULL);
2481 }
2482
2483 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2484 {
2485         seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2486         return 0;
2487 }
2488
2489 static int sg_proc_single_open_devhdr(struct inode *inode, struct file *file)
2490 {
2491         return single_open(file, sg_proc_seq_show_devhdr, NULL);
2492 }
2493
2494 struct sg_proc_deviter {
2495         loff_t  index;
2496         size_t  max;
2497 };
2498
2499 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2500 {
2501         struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2502
2503         s->private = it;
2504         if (! it)
2505                 return NULL;
2506
2507         it->index = *pos;
2508         it->max = sg_last_dev();
2509         if (it->index >= it->max)
2510                 return NULL;
2511         return it;
2512 }
2513
2514 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2515 {
2516         struct sg_proc_deviter * it = s->private;
2517
2518         *pos = ++it->index;
2519         return (it->index < it->max) ? it : NULL;
2520 }
2521
2522 static void dev_seq_stop(struct seq_file *s, void *v)
2523 {
2524         kfree(s->private);
2525 }
2526
2527 static int sg_proc_open_dev(struct inode *inode, struct file *file)
2528 {
2529         return seq_open(file, &dev_seq_ops);
2530 }
2531
2532 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2533 {
2534         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2535         Sg_device *sdp;
2536         struct scsi_device *scsidp;
2537         unsigned long iflags;
2538
2539         read_lock_irqsave(&sg_index_lock, iflags);
2540         sdp = it ? sg_lookup_dev(it->index) : NULL;
2541         if ((NULL == sdp) || (NULL == sdp->device) ||
2542             (atomic_read(&sdp->detaching)))
2543                 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2544         else {
2545                 scsidp = sdp->device;
2546                 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2547                               scsidp->host->host_no, scsidp->channel,
2548                               scsidp->id, scsidp->lun, (int) scsidp->type,
2549                               1,
2550                               (int) scsidp->queue_depth,
2551                               (int) atomic_read(&scsidp->device_busy),
2552                               (int) scsi_device_online(scsidp));
2553         }
2554         read_unlock_irqrestore(&sg_index_lock, iflags);
2555         return 0;
2556 }
2557
2558 static int sg_proc_open_devstrs(struct inode *inode, struct file *file)
2559 {
2560         return seq_open(file, &devstrs_seq_ops);
2561 }
2562
2563 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2564 {
2565         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2566         Sg_device *sdp;
2567         struct scsi_device *scsidp;
2568         unsigned long iflags;
2569
2570         read_lock_irqsave(&sg_index_lock, iflags);
2571         sdp = it ? sg_lookup_dev(it->index) : NULL;
2572         scsidp = sdp ? sdp->device : NULL;
2573         if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2574                 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2575                            scsidp->vendor, scsidp->model, scsidp->rev);
2576         else
2577                 seq_puts(s, "<no active device>\n");
2578         read_unlock_irqrestore(&sg_index_lock, iflags);
2579         return 0;
2580 }
2581
2582 /* must be called while holding sg_index_lock */
2583 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2584 {
2585         int k, m, new_interface, blen, usg;
2586         Sg_request *srp;
2587         Sg_fd *fp;
2588         const sg_io_hdr_t *hp;
2589         const char * cp;
2590         unsigned int ms;
2591
2592         k = 0;
2593         list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2594                 k++;
2595                 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2596                 seq_printf(s, "   FD(%d): timeout=%dms bufflen=%d "
2597                            "(res)sgat=%d low_dma=%d\n", k,
2598                            jiffies_to_msecs(fp->timeout),
2599                            fp->reserve.bufflen,
2600                            (int) fp->reserve.k_use_sg,
2601                            (int) fp->low_dma);
2602                 seq_printf(s, "   cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2603                            (int) fp->cmd_q, (int) fp->force_packid,
2604                            (int) fp->keep_orphan);
2605                 for (m = 0, srp = fp->headrp;
2606                                 srp != NULL;
2607                                 ++m, srp = srp->nextrp) {
2608                         hp = &srp->header;
2609                         new_interface = (hp->interface_id == '\0') ? 0 : 1;
2610                         if (srp->res_used) {
2611                                 if (new_interface &&
2612                                     (SG_FLAG_MMAP_IO & hp->flags))
2613                                         cp = "     mmap>> ";
2614                                 else
2615                                         cp = "     rb>> ";
2616                         } else {
2617                                 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2618                                         cp = "     dio>> ";
2619                                 else
2620                                         cp = "     ";
2621                         }
2622                         seq_puts(s, cp);
2623                         blen = srp->data.bufflen;
2624                         usg = srp->data.k_use_sg;
2625                         seq_puts(s, srp->done ?
2626                                  ((1 == srp->done) ?  "rcv:" : "fin:")
2627                                   : "act:");
2628                         seq_printf(s, " id=%d blen=%d",
2629                                    srp->header.pack_id, blen);
2630                         if (srp->done)
2631                                 seq_printf(s, " dur=%d", hp->duration);
2632                         else {
2633                                 ms = jiffies_to_msecs(jiffies);
2634                                 seq_printf(s, " t_o/elap=%d/%d",
2635                                         (new_interface ? hp->timeout :
2636                                                   jiffies_to_msecs(fp->timeout)),
2637                                         (ms > hp->duration ? ms - hp->duration : 0));
2638                         }
2639                         seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2640                                    (int) srp->data.cmd_opcode);
2641                 }
2642                 if (0 == m)
2643                         seq_puts(s, "     No requests active\n");
2644                 read_unlock(&fp->rq_list_lock);
2645         }
2646 }
2647
2648 static int sg_proc_open_debug(struct inode *inode, struct file *file)
2649 {
2650         return seq_open(file, &debug_seq_ops);
2651 }
2652
2653 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2654 {
2655         struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2656         Sg_device *sdp;
2657         unsigned long iflags;
2658
2659         if (it && (0 == it->index))
2660                 seq_printf(s, "max_active_device=%d  def_reserved_size=%d\n",
2661                            (int)it->max, sg_big_buff);
2662
2663         read_lock_irqsave(&sg_index_lock, iflags);
2664         sdp = it ? sg_lookup_dev(it->index) : NULL;
2665         if (NULL == sdp)
2666                 goto skip;
2667         read_lock(&sdp->sfd_lock);
2668         if (!list_empty(&sdp->sfds)) {
2669                 seq_printf(s, " >>> device=%s ", sdp->disk->disk_name);
2670                 if (atomic_read(&sdp->detaching))
2671                         seq_puts(s, "detaching pending close ");
2672                 else if (sdp->device) {
2673                         struct scsi_device *scsidp = sdp->device;
2674
2675                         seq_printf(s, "%d:%d:%d:%llu   em=%d",
2676                                    scsidp->host->host_no,
2677                                    scsidp->channel, scsidp->id,
2678                                    scsidp->lun,
2679                                    scsidp->host->hostt->emulated);
2680                 }
2681                 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2682                            sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2683                 sg_proc_debug_helper(s, sdp);
2684         }
2685         read_unlock(&sdp->sfd_lock);
2686 skip:
2687         read_unlock_irqrestore(&sg_index_lock, iflags);
2688         return 0;
2689 }
2690
2691 #endif                          /* CONFIG_SCSI_PROC_FS */
2692
2693 module_init(init_sg);
2694 module_exit(exit_sg);