drivers/staging/lustre/lustre/llite/vvp_dev.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * cl_device and cl_device_type implementation for VVP layer.
  37  *
  38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_LLITE
  42
  43
  44 #include <obd.h>
  45 #include <lustre_lite.h>
  46
  47 #include "vvp_internal.h"
  48
  49 /*****************************************************************************
  50  *
  51  * Vvp device and device type functions.
  52  *
  53  */
  54
  55 /*
  56  * vvp_ prefix stands for "Vfs Vm Posix". It corresponds to historical
  57  * "llite_" (var. "ll_") prefix.
  58  */
  59
  60 struct kmem_cache *vvp_thread_kmem;
  61 static struct kmem_cache *vvp_session_kmem;
  62 static struct lu_kmem_descr vvp_caches[] = {
  63         {
  64                 .ckd_cache = &vvp_thread_kmem,
  65                 .ckd_name  = "vvp_thread_kmem",
  66                 .ckd_size  = sizeof (struct vvp_thread_info),
  67         },
  68         {
  69                 .ckd_cache = &vvp_session_kmem,
  70                 .ckd_name  = "vvp_session_kmem",
  71                 .ckd_size  = sizeof (struct vvp_session)
  72         },
  73         {
  74                 .ckd_cache = NULL
  75         }
  76 };
  77
  78 static void *vvp_key_init(const struct lu_context *ctx,
  79                           struct lu_context_key *key)
  80 {
  81         struct vvp_thread_info *info;
  82
  83         OBD_SLAB_ALLOC_PTR_GFP(info, vvp_thread_kmem, __GFP_IO);
  84         if (info == NULL)
  85                 info = ERR_PTR(-ENOMEM);
  86         return info;
  87 }
  88
  89 static void vvp_key_fini(const struct lu_context *ctx,
  90                          struct lu_context_key *key, void *data)
  91 {
  92         struct vvp_thread_info *info = data;
  93         OBD_SLAB_FREE_PTR(info, vvp_thread_kmem);
  94 }
  95
  96 static void *vvp_session_key_init(const struct lu_context *ctx,
  97                                   struct lu_context_key *key)
  98 {
  99         struct vvp_session *session;
 100
 101         OBD_SLAB_ALLOC_PTR_GFP(session, vvp_session_kmem, __GFP_IO);
 102         if (session == NULL)
 103                 session = ERR_PTR(-ENOMEM);
 104         return session;
 105 }
 106
 107 static void vvp_session_key_fini(const struct lu_context *ctx,
 108                                  struct lu_context_key *key, void *data)
 109 {
 110         struct vvp_session *session = data;
 111         OBD_SLAB_FREE_PTR(session, vvp_session_kmem);
 112 }
 113
 114
 115 struct lu_context_key vvp_key = {
 116         .lct_tags = LCT_CL_THREAD,
 117         .lct_init = vvp_key_init,
 118         .lct_fini = vvp_key_fini
 119 };
 120
 121 struct lu_context_key vvp_session_key = {
 122         .lct_tags = LCT_SESSION,
 123         .lct_init = vvp_session_key_init,
 124         .lct_fini = vvp_session_key_fini
 125 };
 126
 127 /* type constructor/destructor: vvp_type_{init,fini,start,stop}(). */
 128 LU_TYPE_INIT_FINI(vvp, &ccc_key, &ccc_session_key, &vvp_key, &vvp_session_key);
 129
 130 static const struct lu_device_operations vvp_lu_ops = {
 131         .ldo_object_alloc      = vvp_object_alloc
 132 };
 133
 134 static const struct cl_device_operations vvp_cl_ops = {
 135         .cdo_req_init = ccc_req_init
 136 };
 137
 138 static struct lu_device *vvp_device_alloc(const struct lu_env *env,
 139                                           struct lu_device_type *t,
 140                                           struct lustre_cfg *cfg)
 141 {
 142         return ccc_device_alloc(env, t, cfg, &vvp_lu_ops, &vvp_cl_ops);
 143 }
 144
 145 static const struct lu_device_type_operations vvp_device_type_ops = {
 146         .ldto_init = vvp_type_init,
 147         .ldto_fini = vvp_type_fini,
 148
 149         .ldto_start = vvp_type_start,
 150         .ldto_stop  = vvp_type_stop,
 151
 152         .ldto_device_alloc = vvp_device_alloc,
 153         .ldto_device_free  = ccc_device_free,
 154         .ldto_device_init  = ccc_device_init,
 155         .ldto_device_fini  = ccc_device_fini
 156 };
 157
 158 struct lu_device_type vvp_device_type = {
 159         .ldt_tags     = LU_DEVICE_CL,
 160         .ldt_name     = LUSTRE_VVP_NAME,
 161         .ldt_ops      = &vvp_device_type_ops,
 162         .ldt_ctx_tags = LCT_CL_THREAD
 163 };
 164
 165 /**
 166  * A mutex serializing calls to vvp_inode_fini() under extreme memory
 167  * pressure, when environments cannot be allocated.
 168  */
 169 int vvp_global_init(void)
 170 {
 171         int result;
 172
 173         result = lu_kmem_init(vvp_caches);
 174         if (result == 0) {
 175                 result = ccc_global_init(&vvp_device_type);
 176                 if (result != 0)
 177                         lu_kmem_fini(vvp_caches);
 178         }
 179         return result;
 180 }
 181
 182 void vvp_global_fini(void)
 183 {
 184         ccc_global_fini(&vvp_device_type);
 185         lu_kmem_fini(vvp_caches);
 186 }
 187
 188
 189 /*****************************************************************************
 190  *
 191  * mirror obd-devices into cl devices.
 192  *
 193  */
 194
 195 int cl_sb_init(struct super_block *sb)
 196 {
 197         struct ll_sb_info *sbi;
 198         struct cl_device  *cl;
 199         struct lu_env     *env;
 200         int rc = 0;
 201         int refcheck;
 202
 203         sbi  = ll_s2sbi(sb);
 204         env = cl_env_get(&refcheck);
 205         if (!IS_ERR(env)) {
 206                 cl = cl_type_setup(env, NULL, &vvp_device_type,
 207                                    sbi->ll_dt_exp->exp_obd->obd_lu_dev);
 208                 if (!IS_ERR(cl)) {
 209                         cl2ccc_dev(cl)->cdv_sb = sb;
 210                         sbi->ll_cl = cl;
 211                         sbi->ll_site = cl2lu_dev(cl)->ld_site;
 212                 }
 213                 cl_env_put(env, &refcheck);
 214         } else
 215                 rc = PTR_ERR(env);
 216         return rc;
 217 }
 218
 219 int cl_sb_fini(struct super_block *sb)
 220 {
 221         struct ll_sb_info *sbi;
 222         struct lu_env     *env;
 223         struct cl_device  *cld;
 224         int             refcheck;
 225         int             result;
 226
 227         sbi = ll_s2sbi(sb);
 228         env = cl_env_get(&refcheck);
 229         if (!IS_ERR(env)) {
 230                 cld = sbi->ll_cl;
 231
 232                 if (cld != NULL) {
 233                         cl_stack_fini(env, cld);
 234                         sbi->ll_cl = NULL;
 235                         sbi->ll_site = NULL;
 236                 }
 237                 cl_env_put(env, &refcheck);
 238                 result = 0;
 239         } else {
 240                 CERROR("Cannot cleanup cl-stack due to memory shortage.\n");
 241                 result = PTR_ERR(env);
 242         }
 243         /*
 244          * If mount failed (sbi->ll_cl == NULL), and this there are no other
 245          * mounts, stop device types manually (this usually happens
 246          * automatically when last device is destroyed).
 247          */
 248         lu_types_stop();
 249         return result;
 250 }
 251
 252 /****************************************************************************
 253  *
 254  * /proc/fs/lustre/llite/$MNT/dump_page_cache
 255  *
 256  ****************************************************************************/
 257
 258 /*
 259  * To represent contents of a page cache as a byte stream, following
 260  * information if encoded in 64bit offset:
 261  *
 262  *       - file hash bucket in lu_site::ls_hash[]       28bits
 263  *
 264  *       - how far file is from bucket head           4bits
 265  *
 266  *       - page index                              32bits
 267  *
 268  * First two data identify a file in the cache uniquely.
 269  */
 270
 271 #define PGC_OBJ_SHIFT (32 + 4)
 272 #define PGC_DEPTH_SHIFT (32)
 273
 274 struct vvp_pgcache_id {
 275         unsigned                 vpi_bucket;
 276         unsigned                 vpi_depth;
 277         uint32_t                 vpi_index;
 278
 279         unsigned                 vpi_curdep;
 280         struct lu_object_header *vpi_obj;
 281 };
 282
 283 static void vvp_pgcache_id_unpack(loff_t pos, struct vvp_pgcache_id *id)
 284 {
 285         CLASSERT(sizeof(pos) == sizeof(__u64));
 286
 287         id->vpi_index  = pos & 0xffffffff;
 288         id->vpi_depth  = (pos >> PGC_DEPTH_SHIFT) & 0xf;
 289         id->vpi_bucket = ((unsigned long long)pos >> PGC_OBJ_SHIFT);
 290 }
 291
 292 static loff_t vvp_pgcache_id_pack(struct vvp_pgcache_id *id)
 293 {
 294         return
 295                 ((__u64)id->vpi_index) |
 296                 ((__u64)id->vpi_depth  << PGC_DEPTH_SHIFT) |
 297                 ((__u64)id->vpi_bucket << PGC_OBJ_SHIFT);
 298 }
 299
 300 static int vvp_pgcache_obj_get(struct cfs_hash *hs, struct cfs_hash_bd *bd,
 301                                struct hlist_node *hnode, void *data)
 302 {
 303         struct vvp_pgcache_id   *id  = data;
 304         struct lu_object_header *hdr = cfs_hash_object(hs, hnode);
 305
 306         if (id->vpi_curdep-- > 0)
 307                 return 0; /* continue */
 308
 309         if (lu_object_is_dying(hdr))
 310                 return 1;
 311
 312         cfs_hash_get(hs, hnode);
 313         id->vpi_obj = hdr;
 314         return 1;
 315 }
 316
 317 static struct cl_object *vvp_pgcache_obj(const struct lu_env *env,
 318                                          struct lu_device *dev,
 319                                          struct vvp_pgcache_id *id)
 320 {
 321         LASSERT(lu_device_is_cl(dev));
 322
 323         id->vpi_depth &= 0xf;
 324         id->vpi_obj    = NULL;
 325         id->vpi_curdep = id->vpi_depth;
 326
 327         cfs_hash_hlist_for_each(dev->ld_site->ls_obj_hash, id->vpi_bucket,
 328                                 vvp_pgcache_obj_get, id);
 329         if (id->vpi_obj != NULL) {
 330                 struct lu_object *lu_obj;
 331
 332                 lu_obj = lu_object_locate(id->vpi_obj, dev->ld_type);
 333                 if (lu_obj != NULL) {
 334                         lu_object_ref_add(lu_obj, "dump", current);
 335                         return lu2cl(lu_obj);
 336                 }
 337                 lu_object_put(env, lu_object_top(id->vpi_obj));
 338
 339         } else if (id->vpi_curdep > 0) {
 340                 id->vpi_depth = 0xf;
 341         }
 342         return NULL;
 343 }
 344
 345 static loff_t vvp_pgcache_find(const struct lu_env *env,
 346                                struct lu_device *dev, loff_t pos)
 347 {
 348         struct cl_object     *clob;
 349         struct lu_site       *site;
 350         struct vvp_pgcache_id id;
 351
 352         site = dev->ld_site;
 353         vvp_pgcache_id_unpack(pos, &id);
 354
 355         while (1) {
 356                 if (id.vpi_bucket >= CFS_HASH_NHLIST(site->ls_obj_hash))
 357                         return ~0ULL;
 358                 clob = vvp_pgcache_obj(env, dev, &id);
 359                 if (clob != NULL) {
 360                         struct cl_object_header *hdr;
 361                         int                   nr;
 362                         struct cl_page    *pg;
 363
 364                         /* got an object. Find next page. */
 365                         hdr = cl_object_header(clob);
 366
 367                         spin_lock(&hdr->coh_page_guard);
 368                         nr = radix_tree_gang_lookup(&hdr->coh_tree,
 369                                                     (void **)&pg,
 370                                                     id.vpi_index, 1);
 371                         if (nr > 0) {
 372                                 id.vpi_index = pg->cp_index;
 373                                 /* Cant support over 16T file */
 374                                 nr = !(pg->cp_index > 0xffffffff);
 375                         }
 376                         spin_unlock(&hdr->coh_page_guard);
 377
 378                         lu_object_ref_del(&clob->co_lu, "dump", current);
 379                         cl_object_put(env, clob);
 380                         if (nr > 0)
 381                                 return vvp_pgcache_id_pack(&id);
 382                 }
 383                 /* to the next object. */
 384                 ++id.vpi_depth;
 385                 id.vpi_depth &= 0xf;
 386                 if (id.vpi_depth == 0 && ++id.vpi_bucket == 0)
 387                         return ~0ULL;
 388                 id.vpi_index = 0;
 389         }
 390 }
 391
 392 #define seq_page_flag(seq, page, flag, has_flags) do {            \
 393         if (test_bit(PG_##flag, &(page)->flags)) {                \
 394                 seq_printf(seq, "%s"#flag, has_flags ? "|" : "");       \
 395                 has_flags = 1;                                    \
 396         }                                                              \
 397 } while(0)
 398
 399 static void vvp_pgcache_page_show(const struct lu_env *env,
 400                                   struct seq_file *seq, struct cl_page *page)
 401 {
 402         struct ccc_page *cpg;
 403         struct page      *vmpage;
 404         int           has_flags;
 405
 406         cpg = cl2ccc_page(cl_page_at(page, &vvp_device_type));
 407         vmpage = cpg->cpg_page;
 408         seq_printf(seq," %5i | %p %p %s %s %s %s | %p %lu/%u(%p) %lu %u [",
 409                    0 /* gen */,
 410                    cpg, page,
 411                    "none",
 412                    cpg->cpg_write_queued ? "wq" : "- ",
 413                    cpg->cpg_defer_uptodate ? "du" : "- ",
 414                    PageWriteback(vmpage) ? "wb" : "-",
 415                    vmpage, vmpage->mapping->host->i_ino,
 416                    vmpage->mapping->host->i_generation,
 417                    vmpage->mapping->host, vmpage->index,
 418                    page_count(vmpage));
 419         has_flags = 0;
 420         seq_page_flag(seq, vmpage, locked, has_flags);
 421         seq_page_flag(seq, vmpage, error, has_flags);
 422         seq_page_flag(seq, vmpage, referenced, has_flags);
 423         seq_page_flag(seq, vmpage, uptodate, has_flags);
 424         seq_page_flag(seq, vmpage, dirty, has_flags);
 425         seq_page_flag(seq, vmpage, writeback, has_flags);
 426         seq_printf(seq, "%s]\n", has_flags ? "" : "-");
 427 }
 428
 429 static int vvp_pgcache_show(struct seq_file *f, void *v)
 430 {
 431         loff_t             pos;
 432         struct ll_sb_info       *sbi;
 433         struct cl_object        *clob;
 434         struct lu_env      *env;
 435         struct cl_page    *page;
 436         struct cl_object_header *hdr;
 437         struct vvp_pgcache_id    id;
 438         int                   refcheck;
 439         int                   result;
 440
 441         env = cl_env_get(&refcheck);
 442         if (!IS_ERR(env)) {
 443                 pos = *(loff_t *) v;
 444                 vvp_pgcache_id_unpack(pos, &id);
 445                 sbi = f->private;
 446                 clob = vvp_pgcache_obj(env, &sbi->ll_cl->cd_lu_dev, &id);
 447                 if (clob != NULL) {
 448                         hdr = cl_object_header(clob);
 449
 450                         spin_lock(&hdr->coh_page_guard);
 451                         page = cl_page_lookup(hdr, id.vpi_index);
 452                         spin_unlock(&hdr->coh_page_guard);
 453
 454                         seq_printf(f, "%8x@"DFID": ",
 455                                    id.vpi_index, PFID(&hdr->coh_lu.loh_fid));
 456                         if (page != NULL) {
 457                                 vvp_pgcache_page_show(env, f, page);
 458                                 cl_page_put(env, page);
 459                         } else
 460                                 seq_puts(f, "missing\n");
 461                         lu_object_ref_del(&clob->co_lu, "dump", current);
 462                         cl_object_put(env, clob);
 463                 } else
 464                         seq_printf(f, "%llx missing\n", pos);
 465                 cl_env_put(env, &refcheck);
 466                 result = 0;
 467         } else
 468                 result = PTR_ERR(env);
 469         return result;
 470 }
 471
 472 static void *vvp_pgcache_start(struct seq_file *f, loff_t *pos)
 473 {
 474         struct ll_sb_info *sbi;
 475         struct lu_env     *env;
 476         int             refcheck;
 477
 478         sbi = f->private;
 479
 480         env = cl_env_get(&refcheck);
 481         if (!IS_ERR(env)) {
 482                 sbi = f->private;
 483                 if (sbi->ll_site->ls_obj_hash->hs_cur_bits > 64 - PGC_OBJ_SHIFT)
 484                         pos = ERR_PTR(-EFBIG);
 485                 else {
 486                         *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev,
 487                                                 *pos);
 488                         if (*pos == ~0ULL)
 489                                 pos = NULL;
 490                 }
 491                 cl_env_put(env, &refcheck);
 492         }
 493         return pos;
 494 }
 495
 496 static void *vvp_pgcache_next(struct seq_file *f, void *v, loff_t *pos)
 497 {
 498         struct ll_sb_info *sbi;
 499         struct lu_env     *env;
 500         int             refcheck;
 501
 502         env = cl_env_get(&refcheck);
 503         if (!IS_ERR(env)) {
 504                 sbi = f->private;
 505                 *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev, *pos + 1);
 506                 if (*pos == ~0ULL)
 507                         pos = NULL;
 508                 cl_env_put(env, &refcheck);
 509         }
 510         return pos;
 511 }
 512
 513 static void vvp_pgcache_stop(struct seq_file *f, void *v)
 514 {
 515         /* Nothing to do */
 516 }
 517
 518 static struct seq_operations vvp_pgcache_ops = {
 519         .start = vvp_pgcache_start,
 520         .next  = vvp_pgcache_next,
 521         .stop  = vvp_pgcache_stop,
 522         .show  = vvp_pgcache_show
 523 };
 524
 525 static int vvp_dump_pgcache_seq_open(struct inode *inode, struct file *filp)
 526 {
 527         struct ll_sb_info     *sbi = PDE_DATA(inode);
 528         struct seq_file       *seq;
 529         int                 result;
 530
 531         result = seq_open(filp, &vvp_pgcache_ops);
 532         if (result == 0) {
 533                 seq = filp->private_data;
 534                 seq->private = sbi;
 535         }
 536         return result;
 537 }
 538
 539 struct file_operations vvp_dump_pgcache_file_ops = {
 540         .owner   = THIS_MODULE,
 541         .open    = vvp_dump_pgcache_seq_open,
 542         .read    = seq_read,
 543         .llseek  = seq_lseek,
 544         .release = seq_release,
 545 };