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, 2013, 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  *   Author: Jinshan Xiong <jinshan.xiong@intel.com>
  40  */
  41
  42 #define DEBUG_SUBSYSTEM S_LLITE
  43
  44 #ifndef __KERNEL__
  45 # error This file is kernel only.
  46 #endif
  47
  48 #include <obd.h>
  49 #include <lustre_lite.h>
  50 #include "llite_internal.h"
  51 #include "vvp_internal.h"
  52
  53 /*****************************************************************************
  54  *
  55  * Vvp device and device type functions.
  56  *
  57  */
  58
  59 /*
  60  * vvp_ prefix stands for "Vfs Vm Posix". It corresponds to historical
  61  * "llite_" (var. "ll_") prefix.
  62  */
  63
  64 static struct kmem_cache *vvp_thread_kmem;
  65 static struct kmem_cache *vvp_session_kmem;
  66 static struct lu_kmem_descr vvp_caches[] = {
  67         {
  68                 .ckd_cache = &vvp_thread_kmem,
  69                 .ckd_name  = "vvp_thread_kmem",
  70                 .ckd_size  = sizeof (struct vvp_thread_info),
  71         },
  72         {
  73                 .ckd_cache = &vvp_session_kmem,
  74                 .ckd_name  = "vvp_session_kmem",
  75                 .ckd_size  = sizeof (struct vvp_session)
  76         },
  77         {
  78                 .ckd_cache = NULL
  79         }
  80 };
  81
  82 static void *vvp_key_init(const struct lu_context *ctx,
  83                           struct lu_context_key *key)
  84 {
  85         struct vvp_thread_info *info;
  86
  87         OBD_SLAB_ALLOC_PTR_GFP(info, vvp_thread_kmem, GFP_NOFS);
  88         if (info == NULL)
  89                 info = ERR_PTR(-ENOMEM);
  90         return info;
  91 }
  92
  93 static void vvp_key_fini(const struct lu_context *ctx,
  94                          struct lu_context_key *key, void *data)
  95 {
  96         struct vvp_thread_info *info = data;
  97         OBD_SLAB_FREE_PTR(info, vvp_thread_kmem);
  98 }
  99
 100 static void *vvp_session_key_init(const struct lu_context *ctx,
 101                                   struct lu_context_key *key)
 102 {
 103         struct vvp_session *session;
 104
 105         OBD_SLAB_ALLOC_PTR_GFP(session, vvp_session_kmem, GFP_NOFS);
 106         if (session == NULL)
 107                 session = ERR_PTR(-ENOMEM);
 108         return session;
 109 }
 110
 111 static void vvp_session_key_fini(const struct lu_context *ctx,
 112                                  struct lu_context_key *key, void *data)
 113 {
 114         struct vvp_session *session = data;
 115         OBD_SLAB_FREE_PTR(session, vvp_session_kmem);
 116 }
 117
 118
 119 struct lu_context_key vvp_key = {
 120         .lct_tags = LCT_CL_THREAD,
 121         .lct_init = vvp_key_init,
 122         .lct_fini = vvp_key_fini
 123 };
 124
 125 struct lu_context_key vvp_session_key = {
 126         .lct_tags = LCT_SESSION,
 127         .lct_init = vvp_session_key_init,
 128         .lct_fini = vvp_session_key_fini
 129 };
 130
 131 /* type constructor/destructor: vvp_type_{init,fini,start,stop}(). */
 132 LU_TYPE_INIT_FINI(vvp, &ccc_key, &ccc_session_key, &vvp_key, &vvp_session_key);
 133
 134 static const struct lu_device_operations vvp_lu_ops = {
 135         .ldo_object_alloc      = vvp_object_alloc
 136 };
 137
 138 static const struct cl_device_operations vvp_cl_ops = {
 139         .cdo_req_init = ccc_req_init
 140 };
 141
 142 static struct lu_device *vvp_device_alloc(const struct lu_env *env,
 143                                           struct lu_device_type *t,
 144                                           struct lustre_cfg *cfg)
 145 {
 146         return ccc_device_alloc(env, t, cfg, &vvp_lu_ops, &vvp_cl_ops);
 147 }
 148
 149 static const struct lu_device_type_operations vvp_device_type_ops = {
 150         .ldto_init = vvp_type_init,
 151         .ldto_fini = vvp_type_fini,
 152
 153         .ldto_start = vvp_type_start,
 154         .ldto_stop  = vvp_type_stop,
 155
 156         .ldto_device_alloc = vvp_device_alloc,
 157         .ldto_device_free  = ccc_device_free,
 158         .ldto_device_init  = ccc_device_init,
 159         .ldto_device_fini  = ccc_device_fini
 160 };
 161
 162 struct lu_device_type vvp_device_type = {
 163         .ldt_tags     = LU_DEVICE_CL,
 164         .ldt_name     = LUSTRE_VVP_NAME,
 165         .ldt_ops      = &vvp_device_type_ops,
 166         .ldt_ctx_tags = LCT_CL_THREAD
 167 };
 168
 169 /**
 170  * A mutex serializing calls to vvp_inode_fini() under extreme memory
 171  * pressure, when environments cannot be allocated.
 172  */
 173 int vvp_global_init(void)
 174 {
 175         int result;
 176
 177         result = lu_kmem_init(vvp_caches);
 178         if (result == 0) {
 179                 result = ccc_global_init(&vvp_device_type);
 180                 if (result != 0)
 181                         lu_kmem_fini(vvp_caches);
 182         }
 183         return result;
 184 }
 185
 186 void vvp_global_fini(void)
 187 {
 188         ccc_global_fini(&vvp_device_type);
 189         lu_kmem_fini(vvp_caches);
 190 }
 191
 192
 193 /*****************************************************************************
 194  *
 195  * mirror obd-devices into cl devices.
 196  *
 197  */
 198
 199 int cl_sb_init(struct super_block *sb)
 200 {
 201         struct ll_sb_info *sbi;
 202         struct cl_device  *cl;
 203         struct lu_env     *env;
 204         int rc = 0;
 205         int refcheck;
 206
 207         sbi  = ll_s2sbi(sb);
 208         env = cl_env_get(&refcheck);
 209         if (!IS_ERR(env)) {
 210                 cl = cl_type_setup(env, NULL, &vvp_device_type,
 211                                    sbi->ll_dt_exp->exp_obd->obd_lu_dev);
 212                 if (!IS_ERR(cl)) {
 213                         cl2ccc_dev(cl)->cdv_sb = sb;
 214                         sbi->ll_cl = cl;
 215                         sbi->ll_site = cl2lu_dev(cl)->ld_site;
 216                 }
 217                 cl_env_put(env, &refcheck);
 218         } else
 219                 rc = PTR_ERR(env);
 220         RETURN(rc);
 221 }
 222
 223 int cl_sb_fini(struct super_block *sb)
 224 {
 225         struct ll_sb_info *sbi;
 226         struct lu_env     *env;
 227         struct cl_device  *cld;
 228         int                refcheck;
 229         int                result;
 230
 231         ENTRY;
 232         sbi = ll_s2sbi(sb);
 233         env = cl_env_get(&refcheck);
 234         if (!IS_ERR(env)) {
 235                 cld = sbi->ll_cl;
 236
 237                 if (cld != NULL) {
 238                         cl_stack_fini(env, cld);
 239                         sbi->ll_cl = NULL;
 240                         sbi->ll_site = NULL;
 241                 }
 242                 cl_env_put(env, &refcheck);
 243                 result = 0;
 244         } else {
 245                 CERROR("Cannot cleanup cl-stack due to memory shortage.\n");
 246                 result = PTR_ERR(env);
 247         }
 248
 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(cfs_hash_t *hs, cfs_hash_bd_t *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 inode *inode = ccc_object_inode(clob);
 361                         struct page *vmpage;
 362                         int nr;
 363
 364                         nr = find_get_pages_contig(inode->i_mapping,
 365                                                    id.vpi_index, 1, &vmpage);
 366                         if (nr > 0) {
 367                                 id.vpi_index = vmpage->index;
 368                                 /* Cant support over 16T file */
 369                                 nr = !(vmpage->index > 0xffffffff);
 370                                 page_cache_release(vmpage);
 371                         }
 372
 373                         lu_object_ref_del(&clob->co_lu, "dump", current);
 374                         cl_object_put(env, clob);
 375                         if (nr > 0)
 376                                 return vvp_pgcache_id_pack(&id);
 377                 }
 378                 /* to the next object. */
 379                 ++id.vpi_depth;
 380                 id.vpi_depth &= 0xf;
 381                 if (id.vpi_depth == 0 && ++id.vpi_bucket == 0)
 382                         return ~0ULL;
 383                 id.vpi_index = 0;
 384         }
 385 }
 386
 387 #define seq_page_flag(seq, page, flag, has_flags) do {                  \
 388         if (test_bit(PG_##flag, &(page)->flags)) {                  \
 389                 seq_printf(seq, "%s"#flag, has_flags ? "|" : "");       \
 390                 has_flags = 1;                                          \
 391         }                                                               \
 392 } while(0)
 393
 394 static void vvp_pgcache_page_show(const struct lu_env *env,
 395                                   struct seq_file *seq, struct cl_page *page)
 396 {
 397         struct ccc_page *cpg;
 398         struct page      *vmpage;
 399         int              has_flags;
 400
 401         cpg = cl2ccc_page(cl_page_at(page, &vvp_device_type));
 402         vmpage = cpg->cpg_page;
 403         seq_printf(seq, " %5i | %p %p %s %s %s %s | %p "DFID"(%p) %lu %u [",
 404                    0 /* gen */,
 405                    cpg, page,
 406                    "none",
 407                    cpg->cpg_write_queued ? "wq" : "- ",
 408                    cpg->cpg_defer_uptodate ? "du" : "- ",
 409                    PageWriteback(vmpage) ? "wb" : "-",
 410                    vmpage,
 411                    PFID(ll_inode2fid(vmpage->mapping->host)),
 412                    vmpage->mapping->host, vmpage->index,
 413                    page_count(vmpage));
 414         has_flags = 0;
 415         seq_page_flag(seq, vmpage, locked, has_flags);
 416         seq_page_flag(seq, vmpage, error, has_flags);
 417         seq_page_flag(seq, vmpage, referenced, has_flags);
 418         seq_page_flag(seq, vmpage, uptodate, has_flags);
 419         seq_page_flag(seq, vmpage, dirty, has_flags);
 420         seq_page_flag(seq, vmpage, writeback, has_flags);
 421         seq_printf(seq, "%s]\n", has_flags ? "" : "-");
 422 }
 423
 424 static int vvp_pgcache_show(struct seq_file *f, void *v)
 425 {
 426         loff_t                   pos;
 427         struct ll_sb_info       *sbi;
 428         struct cl_object        *clob;
 429         struct lu_env           *env;
 430         struct vvp_pgcache_id    id;
 431         int                      refcheck;
 432         int                      result;
 433
 434         env = cl_env_get(&refcheck);
 435         if (!IS_ERR(env)) {
 436                 pos = *(loff_t *) v;
 437                 vvp_pgcache_id_unpack(pos, &id);
 438                 sbi = f->private;
 439                 clob = vvp_pgcache_obj(env, &sbi->ll_cl->cd_lu_dev, &id);
 440                 if (clob != NULL) {
 441                         struct inode *inode = ccc_object_inode(clob);
 442                         struct cl_page *page = NULL;
 443                         struct page *vmpage;
 444
 445                         result = find_get_pages_contig(inode->i_mapping,
 446                                                       id.vpi_index, 1, &vmpage);
 447                         if (result > 0) {
 448                                 lock_page(vmpage);
 449                                 page = cl_vmpage_page(vmpage, clob);
 450                                 unlock_page(vmpage);
 451
 452                                 page_cache_release(vmpage);
 453                         }
 454
 455                         seq_printf(f, "%8x@"DFID": ", id.vpi_index,
 456                                    PFID(lu_object_fid(&clob->co_lu)));
 457                         if (page != NULL) {
 458                                 vvp_pgcache_page_show(env, f, page);
 459                                 cl_page_put(env, page);
 460                         } else
 461                                 seq_puts(f, "missing\n");
 462                         lu_object_ref_del(&clob->co_lu, "dump", current);
 463                         cl_object_put(env, clob);
 464                 } else
 465                         seq_printf(f, "%llx missing\n", pos);
 466                 cl_env_put(env, &refcheck);
 467                 result = 0;
 468         } else
 469                 result = PTR_ERR(env);
 470         return result;
 471 }
 472
 473 static void *vvp_pgcache_start(struct seq_file *f, loff_t *pos)
 474 {
 475         struct ll_sb_info *sbi;
 476         struct lu_env     *env;
 477         int                refcheck;
 478
 479         sbi = f->private;
 480
 481         env = cl_env_get(&refcheck);
 482         if (!IS_ERR(env)) {
 483                 sbi = f->private;
 484                 if (sbi->ll_site->ls_obj_hash->hs_cur_bits > 64 - PGC_OBJ_SHIFT)
 485                         pos = ERR_PTR(-EFBIG);
 486                 else {
 487                         *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev,
 488                                                 *pos);
 489                         if (*pos == ~0ULL)
 490                                 pos = NULL;
 491                 }
 492                 cl_env_put(env, &refcheck);
 493         }
 494         return pos;
 495 }
 496
 497 static void *vvp_pgcache_next(struct seq_file *f, void *v, loff_t *pos)
 498 {
 499         struct ll_sb_info *sbi;
 500         struct lu_env     *env;
 501         int                refcheck;
 502
 503         env = cl_env_get(&refcheck);
 504         if (!IS_ERR(env)) {
 505                 sbi = f->private;
 506                 *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev, *pos + 1);
 507                 if (*pos == ~0ULL)
 508                         pos = NULL;
 509                 cl_env_put(env, &refcheck);
 510         }
 511         return pos;
 512 }
 513
 514 static void vvp_pgcache_stop(struct seq_file *f, void *v)
 515 {
 516         /* Nothing to do */
 517 }
 518
 519 static struct seq_operations vvp_pgcache_ops = {
 520         .start = vvp_pgcache_start,
 521         .next  = vvp_pgcache_next,
 522         .stop  = vvp_pgcache_stop,
 523         .show  = vvp_pgcache_show
 524 };
 525
 526 static int vvp_dump_pgcache_seq_open(struct inode *inode, struct file *filp)
 527 {
 528         struct ll_sb_info       *sbi = PDE_DATA(inode);
 529         struct seq_file         *seq;
 530         int                     result;
 531
 532         result = seq_open(filp, &vvp_pgcache_ops);
 533         if (result == 0) {
 534                 seq = filp->private_data;
 535                 seq->private = sbi;
 536         }
 537         return result;
 538 }
 539
 540 const struct file_operations vvp_dump_pgcache_file_ops = {
 541         .owner   = THIS_MODULE,
 542         .open    = vvp_dump_pgcache_seq_open,
 543         .read    = seq_read,
 544         .llseek  = seq_lseek,
 545         .release = seq_release,
 546 };