fs/ocfs2/localalloc.c

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This source file includes following definitions.
ocfs2_la_default_mb
ocfs2_la_set_sizes
ocfs2_la_state_enabled
ocfs2_local_alloc_seen_free_bits
ocfs2_la_enable_worker
ocfs2_alloc_should_use_local
ocfs2_load_local_alloc
ocfs2_shutdown_local_alloc
ocfs2_begin_local_alloc_recovery
ocfs2_complete_local_alloc_recovery
ocfs2_reserve_local_alloc_bits
ocfs2_claim_local_alloc_bits
ocfs2_free_local_alloc_bits
ocfs2_local_alloc_count_bits
ocfs2_local_alloc_find_clear_bits
ocfs2_clear_local_alloc
ocfs2_verify_zero_bits
ocfs2_sync_local_to_main
ocfs2_recalc_la_window
ocfs2_local_alloc_reserve_for_window
ocfs2_local_alloc_new_window
ocfs2_local_alloc_slide_window
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* -*- mode: c; c-basic-offset: 8; -*-
   3  * vim: noexpandtab sw=8 ts=8 sts=0:
   4  *
   5  * localalloc.c
   6  *
   7  * Node local data allocation
   8  *
   9  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10  */
  11 
  12 #include <linux/fs.h>
  13 #include <linux/types.h>
  14 #include <linux/slab.h>
  15 #include <linux/highmem.h>
  16 #include <linux/bitops.h>
  17 
  18 #include <cluster/masklog.h>
  19 
  20 #include "ocfs2.h"
  21 
  22 #include "alloc.h"
  23 #include "blockcheck.h"
  24 #include "dlmglue.h"
  25 #include "inode.h"
  26 #include "journal.h"
  27 #include "localalloc.h"
  28 #include "suballoc.h"
  29 #include "super.h"
  30 #include "sysfile.h"
  31 #include "ocfs2_trace.h"
  32 
  33 #include "buffer_head_io.h"
  34 
  35 #define OCFS2_LOCAL_ALLOC(dinode)       (&((dinode)->id2.i_lab))
  36 
  37 static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc);
  38 
  39 static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
  40                                              struct ocfs2_dinode *alloc,
  41                                              u32 *numbits,
  42                                              struct ocfs2_alloc_reservation *resv);
  43 
  44 static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc);
  45 
  46 static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
  47                                     handle_t *handle,
  48                                     struct ocfs2_dinode *alloc,
  49                                     struct inode *main_bm_inode,
  50                                     struct buffer_head *main_bm_bh);
  51 
  52 static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
  53                                                 struct ocfs2_alloc_context **ac,
  54                                                 struct inode **bitmap_inode,
  55                                                 struct buffer_head **bitmap_bh);
  56 
  57 static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
  58                                         handle_t *handle,
  59                                         struct ocfs2_alloc_context *ac);
  60 
  61 static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
  62                                           struct inode *local_alloc_inode);
  63 
  64 /*
  65  * ocfs2_la_default_mb() - determine a default size, in megabytes of
  66  * the local alloc.
  67  *
  68  * Generally, we'd like to pick as large a local alloc as
  69  * possible. Performance on large workloads tends to scale
  70  * proportionally to la size. In addition to that, the reservations
  71  * code functions more efficiently as it can reserve more windows for
  72  * write.
  73  *
  74  * Some things work against us when trying to choose a large local alloc:
  75  *
  76  * - We need to ensure our sizing is picked to leave enough space in
  77  *   group descriptors for other allocations (such as block groups,
  78  *   etc). Picking default sizes which are a multiple of 4 could help
  79  *   - block groups are allocated in 2mb and 4mb chunks.
  80  *
  81  * - Likewise, we don't want to starve other nodes of bits on small
  82  *   file systems. This can easily be taken care of by limiting our
  83  *   default to a reasonable size (256M) on larger cluster sizes.
  84  *
  85  * - Some file systems can't support very large sizes - 4k and 8k in
  86  *   particular are limited to less than 128 and 256 megabytes respectively.
  87  *
  88  * The following reference table shows group descriptor and local
  89  * alloc maximums at various cluster sizes (4k blocksize)
  90  *
  91  * csize: 4K    group: 126M     la: 121M
  92  * csize: 8K    group: 252M     la: 243M
  93  * csize: 16K   group: 504M     la: 486M
  94  * csize: 32K   group: 1008M    la: 972M
  95  * csize: 64K   group: 2016M    la: 1944M
  96  * csize: 128K  group: 4032M    la: 3888M
  97  * csize: 256K  group: 8064M    la: 7776M
  98  * csize: 512K  group: 16128M   la: 15552M
  99  * csize: 1024K group: 32256M   la: 31104M
 100  */
 101 #define OCFS2_LA_MAX_DEFAULT_MB 256
 102 #define OCFS2_LA_OLD_DEFAULT    8
 103 unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
 104 {
 105         unsigned int la_mb;
 106         unsigned int gd_mb;
 107         unsigned int la_max_mb;
 108         unsigned int megs_per_slot;
 109         struct super_block *sb = osb->sb;
 110 
 111         gd_mb = ocfs2_clusters_to_megabytes(osb->sb,
 112                 8 * ocfs2_group_bitmap_size(sb, 0, osb->s_feature_incompat));
 113 
 114         /*
 115          * This takes care of files systems with very small group
 116          * descriptors - 512 byte blocksize at cluster sizes lower
 117          * than 16K and also 1k blocksize with 4k cluster size.
 118          */
 119         if ((sb->s_blocksize == 512 && osb->s_clustersize <= 8192)
 120             || (sb->s_blocksize == 1024 && osb->s_clustersize == 4096))
 121                 return OCFS2_LA_OLD_DEFAULT;
 122 
 123         /*
 124          * Leave enough room for some block groups and make the final
 125          * value we work from a multiple of 4.
 126          */
 127         gd_mb -= 16;
 128         gd_mb &= 0xFFFFFFFB;
 129 
 130         la_mb = gd_mb;
 131 
 132         /*
 133          * Keep window sizes down to a reasonable default
 134          */
 135         if (la_mb > OCFS2_LA_MAX_DEFAULT_MB) {
 136                 /*
 137                  * Some clustersize / blocksize combinations will have
 138                  * given us a larger than OCFS2_LA_MAX_DEFAULT_MB
 139                  * default size, but get poor distribution when
 140                  * limited to exactly 256 megabytes.
 141                  *
 142                  * As an example, 16K clustersize at 4K blocksize
 143                  * gives us a cluster group size of 504M. Paring the
 144                  * local alloc size down to 256 however, would give us
 145                  * only one window and around 200MB left in the
 146                  * cluster group. Instead, find the first size below
 147                  * 256 which would give us an even distribution.
 148                  *
 149                  * Larger cluster group sizes actually work out pretty
 150                  * well when pared to 256, so we don't have to do this
 151                  * for any group that fits more than two
 152                  * OCFS2_LA_MAX_DEFAULT_MB windows.
 153                  */
 154                 if (gd_mb > (2 * OCFS2_LA_MAX_DEFAULT_MB))
 155                         la_mb = 256;
 156                 else {
 157                         unsigned int gd_mult = gd_mb;
 158 
 159                         while (gd_mult > 256)
 160                                 gd_mult = gd_mult >> 1;
 161 
 162                         la_mb = gd_mult;
 163                 }
 164         }
 165 
 166         megs_per_slot = osb->osb_clusters_at_boot / osb->max_slots;
 167         megs_per_slot = ocfs2_clusters_to_megabytes(osb->sb, megs_per_slot);
 168         /* Too many nodes, too few disk clusters. */
 169         if (megs_per_slot < la_mb)
 170                 la_mb = megs_per_slot;
 171 
 172         /* We can't store more bits than we can in a block. */
 173         la_max_mb = ocfs2_clusters_to_megabytes(osb->sb,
 174                                                 ocfs2_local_alloc_size(sb) * 8);
 175         if (la_mb > la_max_mb)
 176                 la_mb = la_max_mb;
 177 
 178         return la_mb;
 179 }
 180 
 181 void ocfs2_la_set_sizes(struct ocfs2_super *osb, int requested_mb)
 182 {
 183         struct super_block *sb = osb->sb;
 184         unsigned int la_default_mb = ocfs2_la_default_mb(osb);
 185         unsigned int la_max_mb;
 186 
 187         la_max_mb = ocfs2_clusters_to_megabytes(sb,
 188                                                 ocfs2_local_alloc_size(sb) * 8);
 189 
 190         trace_ocfs2_la_set_sizes(requested_mb, la_max_mb, la_default_mb);
 191 
 192         if (requested_mb == -1) {
 193                 /* No user request - use defaults */
 194                 osb->local_alloc_default_bits =
 195                         ocfs2_megabytes_to_clusters(sb, la_default_mb);
 196         } else if (requested_mb > la_max_mb) {
 197                 /* Request is too big, we give the maximum available */
 198                 osb->local_alloc_default_bits =
 199                         ocfs2_megabytes_to_clusters(sb, la_max_mb);
 200         } else {
 201                 osb->local_alloc_default_bits =
 202                         ocfs2_megabytes_to_clusters(sb, requested_mb);
 203         }
 204 
 205         osb->local_alloc_bits = osb->local_alloc_default_bits;
 206 }
 207 
 208 static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
 209 {
 210         return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
 211                 osb->local_alloc_state == OCFS2_LA_ENABLED);
 212 }
 213 
 214 void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb,
 215                                       unsigned int num_clusters)
 216 {
 217         spin_lock(&osb->osb_lock);
 218         if (osb->local_alloc_state == OCFS2_LA_DISABLED ||
 219             osb->local_alloc_state == OCFS2_LA_THROTTLED)
 220                 if (num_clusters >= osb->local_alloc_default_bits) {
 221                         cancel_delayed_work(&osb->la_enable_wq);
 222                         osb->local_alloc_state = OCFS2_LA_ENABLED;
 223                 }
 224         spin_unlock(&osb->osb_lock);
 225 }
 226 
 227 void ocfs2_la_enable_worker(struct work_struct *work)
 228 {
 229         struct ocfs2_super *osb =
 230                 container_of(work, struct ocfs2_super,
 231                              la_enable_wq.work);
 232         spin_lock(&osb->osb_lock);
 233         osb->local_alloc_state = OCFS2_LA_ENABLED;
 234         spin_unlock(&osb->osb_lock);
 235 }
 236 
 237 /*
 238  * Tell us whether a given allocation should use the local alloc
 239  * file. Otherwise, it has to go to the main bitmap.
 240  *
 241  * This function does semi-dirty reads of local alloc size and state!
 242  * This is ok however, as the values are re-checked once under mutex.
 243  */
 244 int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
 245 {
 246         int ret = 0;
 247         int la_bits;
 248 
 249         spin_lock(&osb->osb_lock);
 250         la_bits = osb->local_alloc_bits;
 251 
 252         if (!ocfs2_la_state_enabled(osb))
 253                 goto bail;
 254 
 255         /* la_bits should be at least twice the size (in clusters) of
 256          * a new block group. We want to be sure block group
 257          * allocations go through the local alloc, so allow an
 258          * allocation to take up to half the bitmap. */
 259         if (bits > (la_bits / 2))
 260                 goto bail;
 261 
 262         ret = 1;
 263 bail:
 264         trace_ocfs2_alloc_should_use_local(
 265              (unsigned long long)bits, osb->local_alloc_state, la_bits, ret);
 266         spin_unlock(&osb->osb_lock);
 267         return ret;
 268 }
 269 
 270 int ocfs2_load_local_alloc(struct ocfs2_super *osb)
 271 {
 272         int status = 0;
 273         struct ocfs2_dinode *alloc = NULL;
 274         struct buffer_head *alloc_bh = NULL;
 275         u32 num_used;
 276         struct inode *inode = NULL;
 277         struct ocfs2_local_alloc *la;
 278 
 279         if (osb->local_alloc_bits == 0)
 280                 goto bail;
 281 
 282         if (osb->local_alloc_bits >= osb->bitmap_cpg) {
 283                 mlog(ML_NOTICE, "Requested local alloc window %d is larger "
 284                      "than max possible %u. Using defaults.\n",
 285                      osb->local_alloc_bits, (osb->bitmap_cpg - 1));
 286                 osb->local_alloc_bits =
 287                         ocfs2_megabytes_to_clusters(osb->sb,
 288                                                     ocfs2_la_default_mb(osb));
 289         }
 290 
 291         /* read the alloc off disk */
 292         inode = ocfs2_get_system_file_inode(osb, LOCAL_ALLOC_SYSTEM_INODE,
 293                                             osb->slot_num);
 294         if (!inode) {
 295                 status = -EINVAL;
 296                 mlog_errno(status);
 297                 goto bail;
 298         }
 299 
 300         status = ocfs2_read_inode_block_full(inode, &alloc_bh,
 301                                              OCFS2_BH_IGNORE_CACHE);
 302         if (status < 0) {
 303                 mlog_errno(status);
 304                 goto bail;
 305         }
 306 
 307         alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
 308         la = OCFS2_LOCAL_ALLOC(alloc);
 309 
 310         if (!(le32_to_cpu(alloc->i_flags) &
 311             (OCFS2_LOCAL_ALLOC_FL|OCFS2_BITMAP_FL))) {
 312                 mlog(ML_ERROR, "Invalid local alloc inode, %llu\n",
 313                      (unsigned long long)OCFS2_I(inode)->ip_blkno);
 314                 status = -EINVAL;
 315                 goto bail;
 316         }
 317 
 318         if ((la->la_size == 0) ||
 319             (le16_to_cpu(la->la_size) > ocfs2_local_alloc_size(inode->i_sb))) {
 320                 mlog(ML_ERROR, "Local alloc size is invalid (la_size = %u)\n",
 321                      le16_to_cpu(la->la_size));
 322                 status = -EINVAL;
 323                 goto bail;
 324         }
 325 
 326         /* do a little verification. */
 327         num_used = ocfs2_local_alloc_count_bits(alloc);
 328 
 329         /* hopefully the local alloc has always been recovered before
 330          * we load it. */
 331         if (num_used
 332             || alloc->id1.bitmap1.i_used
 333             || alloc->id1.bitmap1.i_total
 334             || la->la_bm_off) {
 335                 mlog(ML_ERROR, "inconsistent detected, clean journal with"
 336                      " unrecovered local alloc, please run fsck.ocfs2!\n"
 337                      "found = %u, set = %u, taken = %u, off = %u\n",
 338                      num_used, le32_to_cpu(alloc->id1.bitmap1.i_used),
 339                      le32_to_cpu(alloc->id1.bitmap1.i_total),
 340                      OCFS2_LOCAL_ALLOC(alloc)->la_bm_off);
 341 
 342                 status = -EINVAL;
 343                 goto bail;
 344         }
 345 
 346         osb->local_alloc_bh = alloc_bh;
 347         osb->local_alloc_state = OCFS2_LA_ENABLED;
 348 
 349 bail:
 350         if (status < 0)
 351                 brelse(alloc_bh);
 352         iput(inode);
 353 
 354         trace_ocfs2_load_local_alloc(osb->local_alloc_bits);
 355 
 356         if (status)
 357                 mlog_errno(status);
 358         return status;
 359 }
 360 
 361 /*
 362  * return any unused bits to the bitmap and write out a clean
 363  * local_alloc.
 364  *
 365  * local_alloc_bh is optional. If not passed, we will simply use the
 366  * one off osb. If you do pass it however, be warned that it *will* be
 367  * returned brelse'd and NULL'd out.*/
 368 void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
 369 {
 370         int status;
 371         handle_t *handle;
 372         struct inode *local_alloc_inode = NULL;
 373         struct buffer_head *bh = NULL;
 374         struct buffer_head *main_bm_bh = NULL;
 375         struct inode *main_bm_inode = NULL;
 376         struct ocfs2_dinode *alloc_copy = NULL;
 377         struct ocfs2_dinode *alloc = NULL;
 378 
 379         cancel_delayed_work(&osb->la_enable_wq);
 380         if (osb->ocfs2_wq)
 381                 flush_workqueue(osb->ocfs2_wq);
 382 
 383         if (osb->local_alloc_state == OCFS2_LA_UNUSED)
 384                 goto out;
 385 
 386         local_alloc_inode =
 387                 ocfs2_get_system_file_inode(osb,
 388                                             LOCAL_ALLOC_SYSTEM_INODE,
 389                                             osb->slot_num);
 390         if (!local_alloc_inode) {
 391                 status = -ENOENT;
 392                 mlog_errno(status);
 393                 goto out;
 394         }
 395 
 396         osb->local_alloc_state = OCFS2_LA_DISABLED;
 397 
 398         ocfs2_resmap_uninit(&osb->osb_la_resmap);
 399 
 400         main_bm_inode = ocfs2_get_system_file_inode(osb,
 401                                                     GLOBAL_BITMAP_SYSTEM_INODE,
 402                                                     OCFS2_INVALID_SLOT);
 403         if (!main_bm_inode) {
 404                 status = -EINVAL;
 405                 mlog_errno(status);
 406                 goto out;
 407         }
 408 
 409         inode_lock(main_bm_inode);
 410 
 411         status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
 412         if (status < 0) {
 413                 mlog_errno(status);
 414                 goto out_mutex;
 415         }
 416 
 417         /* WINDOW_MOVE_CREDITS is a bit heavy... */
 418         handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
 419         if (IS_ERR(handle)) {
 420                 mlog_errno(PTR_ERR(handle));
 421                 handle = NULL;
 422                 goto out_unlock;
 423         }
 424 
 425         bh = osb->local_alloc_bh;
 426         alloc = (struct ocfs2_dinode *) bh->b_data;
 427 
 428         alloc_copy = kmemdup(alloc, bh->b_size, GFP_NOFS);
 429         if (!alloc_copy) {
 430                 status = -ENOMEM;
 431                 goto out_commit;
 432         }
 433 
 434         status = ocfs2_journal_access_di(handle, INODE_CACHE(local_alloc_inode),
 435                                          bh, OCFS2_JOURNAL_ACCESS_WRITE);
 436         if (status < 0) {
 437                 mlog_errno(status);
 438                 goto out_commit;
 439         }
 440 
 441         ocfs2_clear_local_alloc(alloc);
 442         ocfs2_journal_dirty(handle, bh);
 443 
 444         brelse(bh);
 445         osb->local_alloc_bh = NULL;
 446         osb->local_alloc_state = OCFS2_LA_UNUSED;
 447 
 448         status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
 449                                           main_bm_inode, main_bm_bh);
 450         if (status < 0)
 451                 mlog_errno(status);
 452 
 453 out_commit:
 454         ocfs2_commit_trans(osb, handle);
 455 
 456 out_unlock:
 457         brelse(main_bm_bh);
 458 
 459         ocfs2_inode_unlock(main_bm_inode, 1);
 460 
 461 out_mutex:
 462         inode_unlock(main_bm_inode);
 463         iput(main_bm_inode);
 464 
 465 out:
 466         iput(local_alloc_inode);
 467 
 468         kfree(alloc_copy);
 469 }
 470 
 471 /*
 472  * We want to free the bitmap bits outside of any recovery context as
 473  * we'll need a cluster lock to do so, but we must clear the local
 474  * alloc before giving up the recovered nodes journal. To solve this,
 475  * we kmalloc a copy of the local alloc before it's change for the
 476  * caller to process with ocfs2_complete_local_alloc_recovery
 477  */
 478 int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb,
 479                                      int slot_num,
 480                                      struct ocfs2_dinode **alloc_copy)
 481 {
 482         int status = 0;
 483         struct buffer_head *alloc_bh = NULL;
 484         struct inode *inode = NULL;
 485         struct ocfs2_dinode *alloc;
 486 
 487         trace_ocfs2_begin_local_alloc_recovery(slot_num);
 488 
 489         *alloc_copy = NULL;
 490 
 491         inode = ocfs2_get_system_file_inode(osb,
 492                                             LOCAL_ALLOC_SYSTEM_INODE,
 493                                             slot_num);
 494         if (!inode) {
 495                 status = -EINVAL;
 496                 mlog_errno(status);
 497                 goto bail;
 498         }
 499 
 500         inode_lock(inode);
 501 
 502         status = ocfs2_read_inode_block_full(inode, &alloc_bh,
 503                                              OCFS2_BH_IGNORE_CACHE);
 504         if (status < 0) {
 505                 mlog_errno(status);
 506                 goto bail;
 507         }
 508 
 509         *alloc_copy = kmalloc(alloc_bh->b_size, GFP_KERNEL);
 510         if (!(*alloc_copy)) {
 511                 status = -ENOMEM;
 512                 goto bail;
 513         }
 514         memcpy((*alloc_copy), alloc_bh->b_data, alloc_bh->b_size);
 515 
 516         alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
 517         ocfs2_clear_local_alloc(alloc);
 518 
 519         ocfs2_compute_meta_ecc(osb->sb, alloc_bh->b_data, &alloc->i_check);
 520         status = ocfs2_write_block(osb, alloc_bh, INODE_CACHE(inode));
 521         if (status < 0)
 522                 mlog_errno(status);
 523 
 524 bail:
 525         if (status < 0) {
 526                 kfree(*alloc_copy);
 527                 *alloc_copy = NULL;
 528         }
 529 
 530         brelse(alloc_bh);
 531 
 532         if (inode) {
 533                 inode_unlock(inode);
 534                 iput(inode);
 535         }
 536 
 537         if (status)
 538                 mlog_errno(status);
 539         return status;
 540 }
 541 
 542 /*
 543  * Step 2: By now, we've completed the journal recovery, we've stamped
 544  * a clean local alloc on disk and dropped the node out of the
 545  * recovery map. Dlm locks will no longer stall, so lets clear out the
 546  * main bitmap.
 547  */
 548 int ocfs2_complete_local_alloc_recovery(struct ocfs2_super *osb,
 549                                         struct ocfs2_dinode *alloc)
 550 {
 551         int status;
 552         handle_t *handle;
 553         struct buffer_head *main_bm_bh = NULL;
 554         struct inode *main_bm_inode;
 555 
 556         main_bm_inode = ocfs2_get_system_file_inode(osb,
 557                                                     GLOBAL_BITMAP_SYSTEM_INODE,
 558                                                     OCFS2_INVALID_SLOT);
 559         if (!main_bm_inode) {
 560                 status = -EINVAL;
 561                 mlog_errno(status);
 562                 goto out;
 563         }
 564 
 565         inode_lock(main_bm_inode);
 566 
 567         status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
 568         if (status < 0) {
 569                 mlog_errno(status);
 570                 goto out_mutex;
 571         }
 572 
 573         handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
 574         if (IS_ERR(handle)) {
 575                 status = PTR_ERR(handle);
 576                 handle = NULL;
 577                 mlog_errno(status);
 578                 goto out_unlock;
 579         }
 580 
 581         /* we want the bitmap change to be recorded on disk asap */
 582         handle->h_sync = 1;
 583 
 584         status = ocfs2_sync_local_to_main(osb, handle, alloc,
 585                                           main_bm_inode, main_bm_bh);
 586         if (status < 0)
 587                 mlog_errno(status);
 588 
 589         ocfs2_commit_trans(osb, handle);
 590 
 591 out_unlock:
 592         ocfs2_inode_unlock(main_bm_inode, 1);
 593 
 594 out_mutex:
 595         inode_unlock(main_bm_inode);
 596 
 597         brelse(main_bm_bh);
 598 
 599         iput(main_bm_inode);
 600 
 601 out:
 602         if (!status)
 603                 ocfs2_init_steal_slots(osb);
 604         if (status)
 605                 mlog_errno(status);
 606         return status;
 607 }
 608 
 609 /*
 610  * make sure we've got at least bits_wanted contiguous bits in the
 611  * local alloc. You lose them when you drop i_mutex.
 612  *
 613  * We will add ourselves to the transaction passed in, but may start
 614  * our own in order to shift windows.
 615  */
 616 int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
 617                                    u32 bits_wanted,
 618                                    struct ocfs2_alloc_context *ac)
 619 {
 620         int status;
 621         struct ocfs2_dinode *alloc;
 622         struct inode *local_alloc_inode;
 623         unsigned int free_bits;
 624 
 625         BUG_ON(!ac);
 626 
 627         local_alloc_inode =
 628                 ocfs2_get_system_file_inode(osb,
 629                                             LOCAL_ALLOC_SYSTEM_INODE,
 630                                             osb->slot_num);
 631         if (!local_alloc_inode) {
 632                 status = -ENOENT;
 633                 mlog_errno(status);
 634                 goto bail;
 635         }
 636 
 637         inode_lock(local_alloc_inode);
 638 
 639         /*
 640          * We must double check state and allocator bits because
 641          * another process may have changed them while holding i_mutex.
 642          */
 643         spin_lock(&osb->osb_lock);
 644         if (!ocfs2_la_state_enabled(osb) ||
 645             (bits_wanted > osb->local_alloc_bits)) {
 646                 spin_unlock(&osb->osb_lock);
 647                 status = -ENOSPC;
 648                 goto bail;
 649         }
 650         spin_unlock(&osb->osb_lock);
 651 
 652         alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
 653 
 654 #ifdef CONFIG_OCFS2_DEBUG_FS
 655         if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
 656             ocfs2_local_alloc_count_bits(alloc)) {
 657                 status = ocfs2_error(osb->sb, "local alloc inode %llu says it has %u used bits, but a count shows %u\n",
 658                                 (unsigned long long)le64_to_cpu(alloc->i_blkno),
 659                                 le32_to_cpu(alloc->id1.bitmap1.i_used),
 660                                 ocfs2_local_alloc_count_bits(alloc));
 661                 goto bail;
 662         }
 663 #endif
 664 
 665         free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
 666                 le32_to_cpu(alloc->id1.bitmap1.i_used);
 667         if (bits_wanted > free_bits) {
 668                 /* uhoh, window change time. */
 669                 status =
 670                         ocfs2_local_alloc_slide_window(osb, local_alloc_inode);
 671                 if (status < 0) {
 672                         if (status != -ENOSPC)
 673                                 mlog_errno(status);
 674                         goto bail;
 675                 }
 676 
 677                 /*
 678                  * Under certain conditions, the window slide code
 679                  * might have reduced the number of bits available or
 680                  * disabled the the local alloc entirely. Re-check
 681                  * here and return -ENOSPC if necessary.
 682                  */
 683                 status = -ENOSPC;
 684                 if (!ocfs2_la_state_enabled(osb))
 685                         goto bail;
 686 
 687                 free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
 688                         le32_to_cpu(alloc->id1.bitmap1.i_used);
 689                 if (bits_wanted > free_bits)
 690                         goto bail;
 691         }
 692 
 693         ac->ac_inode = local_alloc_inode;
 694         /* We should never use localalloc from another slot */
 695         ac->ac_alloc_slot = osb->slot_num;
 696         ac->ac_which = OCFS2_AC_USE_LOCAL;
 697         get_bh(osb->local_alloc_bh);
 698         ac->ac_bh = osb->local_alloc_bh;
 699         status = 0;
 700 bail:
 701         if (status < 0 && local_alloc_inode) {
 702                 inode_unlock(local_alloc_inode);
 703                 iput(local_alloc_inode);
 704         }
 705 
 706         trace_ocfs2_reserve_local_alloc_bits(
 707                 (unsigned long long)ac->ac_max_block,
 708                 bits_wanted, osb->slot_num, status);
 709 
 710         if (status)
 711                 mlog_errno(status);
 712         return status;
 713 }
 714 
 715 int ocfs2_claim_local_alloc_bits(struct ocfs2_super *osb,
 716                                  handle_t *handle,
 717                                  struct ocfs2_alloc_context *ac,
 718                                  u32 bits_wanted,
 719                                  u32 *bit_off,
 720                                  u32 *num_bits)
 721 {
 722         int status, start;
 723         struct inode *local_alloc_inode;
 724         void *bitmap;
 725         struct ocfs2_dinode *alloc;
 726         struct ocfs2_local_alloc *la;
 727 
 728         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
 729 
 730         local_alloc_inode = ac->ac_inode;
 731         alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
 732         la = OCFS2_LOCAL_ALLOC(alloc);
 733 
 734         start = ocfs2_local_alloc_find_clear_bits(osb, alloc, &bits_wanted,
 735                                                   ac->ac_resv);
 736         if (start == -1) {
 737                 /* TODO: Shouldn't we just BUG here? */
 738                 status = -ENOSPC;
 739                 mlog_errno(status);
 740                 goto bail;
 741         }
 742 
 743         bitmap = la->la_bitmap;
 744         *bit_off = le32_to_cpu(la->la_bm_off) + start;
 745         *num_bits = bits_wanted;
 746 
 747         status = ocfs2_journal_access_di(handle,
 748                                          INODE_CACHE(local_alloc_inode),
 749                                          osb->local_alloc_bh,
 750                                          OCFS2_JOURNAL_ACCESS_WRITE);
 751         if (status < 0) {
 752                 mlog_errno(status);
 753                 goto bail;
 754         }
 755 
 756         ocfs2_resmap_claimed_bits(&osb->osb_la_resmap, ac->ac_resv, start,
 757                                   bits_wanted);
 758 
 759         while(bits_wanted--)
 760                 ocfs2_set_bit(start++, bitmap);
 761 
 762         le32_add_cpu(&alloc->id1.bitmap1.i_used, *num_bits);
 763         ocfs2_journal_dirty(handle, osb->local_alloc_bh);
 764 
 765 bail:
 766         if (status)
 767                 mlog_errno(status);
 768         return status;
 769 }
 770 
 771 int ocfs2_free_local_alloc_bits(struct ocfs2_super *osb,
 772                                 handle_t *handle,
 773                                 struct ocfs2_alloc_context *ac,
 774                                 u32 bit_off,
 775                                 u32 num_bits)
 776 {
 777         int status, start;
 778         u32 clear_bits;
 779         struct inode *local_alloc_inode;
 780         void *bitmap;
 781         struct ocfs2_dinode *alloc;
 782         struct ocfs2_local_alloc *la;
 783 
 784         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
 785 
 786         local_alloc_inode = ac->ac_inode;
 787         alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
 788         la = OCFS2_LOCAL_ALLOC(alloc);
 789 
 790         bitmap = la->la_bitmap;
 791         start = bit_off - le32_to_cpu(la->la_bm_off);
 792         clear_bits = num_bits;
 793 
 794         status = ocfs2_journal_access_di(handle,
 795                         INODE_CACHE(local_alloc_inode),
 796                         osb->local_alloc_bh,
 797                         OCFS2_JOURNAL_ACCESS_WRITE);
 798         if (status < 0) {
 799                 mlog_errno(status);
 800                 goto bail;
 801         }
 802 
 803         while (clear_bits--)
 804                 ocfs2_clear_bit(start++, bitmap);
 805 
 806         le32_add_cpu(&alloc->id1.bitmap1.i_used, -num_bits);
 807         ocfs2_journal_dirty(handle, osb->local_alloc_bh);
 808 
 809 bail:
 810         return status;
 811 }
 812 
 813 static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc)
 814 {
 815         u32 count;
 816         struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
 817 
 818         count = memweight(la->la_bitmap, le16_to_cpu(la->la_size));
 819 
 820         trace_ocfs2_local_alloc_count_bits(count);
 821         return count;
 822 }
 823 
 824 static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
 825                                      struct ocfs2_dinode *alloc,
 826                                      u32 *numbits,
 827                                      struct ocfs2_alloc_reservation *resv)
 828 {
 829         int numfound = 0, bitoff, left, startoff;
 830         int local_resv = 0;
 831         struct ocfs2_alloc_reservation r;
 832         void *bitmap = NULL;
 833         struct ocfs2_reservation_map *resmap = &osb->osb_la_resmap;
 834 
 835         if (!alloc->id1.bitmap1.i_total) {
 836                 bitoff = -1;
 837                 goto bail;
 838         }
 839 
 840         if (!resv) {
 841                 local_resv = 1;
 842                 ocfs2_resv_init_once(&r);
 843                 ocfs2_resv_set_type(&r, OCFS2_RESV_FLAG_TMP);
 844                 resv = &r;
 845         }
 846 
 847         numfound = *numbits;
 848         if (ocfs2_resmap_resv_bits(resmap, resv, &bitoff, &numfound) == 0) {
 849                 if (numfound < *numbits)
 850                         *numbits = numfound;
 851                 goto bail;
 852         }
 853 
 854         /*
 855          * Code error. While reservations are enabled, local
 856          * allocation should _always_ go through them.
 857          */
 858         BUG_ON(osb->osb_resv_level != 0);
 859 
 860         /*
 861          * Reservations are disabled. Handle this the old way.
 862          */
 863 
 864         bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;
 865 
 866         numfound = bitoff = startoff = 0;
 867         left = le32_to_cpu(alloc->id1.bitmap1.i_total);
 868         while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
 869                 if (bitoff == left) {
 870                         /* mlog(0, "bitoff (%d) == left", bitoff); */
 871                         break;
 872                 }
 873                 /* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
 874                    "numfound = %d\n", bitoff, startoff, numfound);*/
 875 
 876                 /* Ok, we found a zero bit... is it contig. or do we
 877                  * start over?*/
 878                 if (bitoff == startoff) {
 879                         /* we found a zero */
 880                         numfound++;
 881                         startoff++;
 882                 } else {
 883                         /* got a zero after some ones */
 884                         numfound = 1;
 885                         startoff = bitoff+1;
 886                 }
 887                 /* we got everything we needed */
 888                 if (numfound == *numbits) {
 889                         /* mlog(0, "Found it all!\n"); */
 890                         break;
 891                 }
 892         }
 893 
 894         trace_ocfs2_local_alloc_find_clear_bits_search_bitmap(bitoff, numfound);
 895 
 896         if (numfound == *numbits)
 897                 bitoff = startoff - numfound;
 898         else
 899                 bitoff = -1;
 900 
 901 bail:
 902         if (local_resv)
 903                 ocfs2_resv_discard(resmap, resv);
 904 
 905         trace_ocfs2_local_alloc_find_clear_bits(*numbits,
 906                 le32_to_cpu(alloc->id1.bitmap1.i_total),
 907                 bitoff, numfound);
 908 
 909         return bitoff;
 910 }
 911 
 912 static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc)
 913 {
 914         struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
 915         int i;
 916 
 917         alloc->id1.bitmap1.i_total = 0;
 918         alloc->id1.bitmap1.i_used = 0;
 919         la->la_bm_off = 0;
 920         for(i = 0; i < le16_to_cpu(la->la_size); i++)
 921                 la->la_bitmap[i] = 0;
 922 }
 923 
 924 #if 0
 925 /* turn this on and uncomment below to aid debugging window shifts. */
 926 static void ocfs2_verify_zero_bits(unsigned long *bitmap,
 927                                    unsigned int start,
 928                                    unsigned int count)
 929 {
 930         unsigned int tmp = count;
 931         while(tmp--) {
 932                 if (ocfs2_test_bit(start + tmp, bitmap)) {
 933                         printk("ocfs2_verify_zero_bits: start = %u, count = "
 934                                "%u\n", start, count);
 935                         printk("ocfs2_verify_zero_bits: bit %u is set!",
 936                                start + tmp);
 937                         BUG();
 938                 }
 939         }
 940 }
 941 #endif
 942 
 943 /*
 944  * sync the local alloc to main bitmap.
 945  *
 946  * assumes you've already locked the main bitmap -- the bitmap inode
 947  * passed is used for caching.
 948  */
 949 static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
 950                                     handle_t *handle,
 951                                     struct ocfs2_dinode *alloc,
 952                                     struct inode *main_bm_inode,
 953                                     struct buffer_head *main_bm_bh)
 954 {
 955         int status = 0;
 956         int bit_off, left, count, start;
 957         u64 la_start_blk;
 958         u64 blkno;
 959         void *bitmap;
 960         struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
 961 
 962         trace_ocfs2_sync_local_to_main(
 963              le32_to_cpu(alloc->id1.bitmap1.i_total),
 964              le32_to_cpu(alloc->id1.bitmap1.i_used));
 965 
 966         if (!alloc->id1.bitmap1.i_total) {
 967                 goto bail;
 968         }
 969 
 970         if (le32_to_cpu(alloc->id1.bitmap1.i_used) ==
 971             le32_to_cpu(alloc->id1.bitmap1.i_total)) {
 972                 goto bail;
 973         }
 974 
 975         la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
 976                                                 le32_to_cpu(la->la_bm_off));
 977         bitmap = la->la_bitmap;
 978         start = count = bit_off = 0;
 979         left = le32_to_cpu(alloc->id1.bitmap1.i_total);
 980 
 981         while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
 982                != -1) {
 983                 if ((bit_off < left) && (bit_off == start)) {
 984                         count++;
 985                         start++;
 986                         continue;
 987                 }
 988                 if (count) {
 989                         blkno = la_start_blk +
 990                                 ocfs2_clusters_to_blocks(osb->sb,
 991                                                          start - count);
 992 
 993                         trace_ocfs2_sync_local_to_main_free(
 994                              count, start - count,
 995                              (unsigned long long)la_start_blk,
 996                              (unsigned long long)blkno);
 997 
 998                         status = ocfs2_release_clusters(handle,
 999                                                         main_bm_inode,
1000                                                         main_bm_bh, blkno,
1001                                                         count);
1002                         if (status < 0) {
1003                                 mlog_errno(status);
1004                                 goto bail;
1005                         }
1006                 }
1007                 if (bit_off >= left)
1008                         break;
1009                 count = 1;
1010                 start = bit_off + 1;
1011         }
1012 
1013 bail:
1014         if (status)
1015                 mlog_errno(status);
1016         return status;
1017 }
1018 
1019 enum ocfs2_la_event {
1020         OCFS2_LA_EVENT_SLIDE,           /* Normal window slide. */
1021         OCFS2_LA_EVENT_FRAGMENTED,      /* The global bitmap has
1022                                          * enough bits theoretically
1023                                          * free, but a contiguous
1024                                          * allocation could not be
1025                                          * found. */
1026         OCFS2_LA_EVENT_ENOSPC,          /* Global bitmap doesn't have
1027                                          * enough bits free to satisfy
1028                                          * our request. */
1029 };
1030 #define OCFS2_LA_ENABLE_INTERVAL (30 * HZ)
1031 /*
1032  * Given an event, calculate the size of our next local alloc window.
1033  *
1034  * This should always be called under i_mutex of the local alloc inode
1035  * so that local alloc disabling doesn't race with processes trying to
1036  * use the allocator.
1037  *
1038  * Returns the state which the local alloc was left in. This value can
1039  * be ignored by some paths.
1040  */
1041 static int ocfs2_recalc_la_window(struct ocfs2_super *osb,
1042                                   enum ocfs2_la_event event)
1043 {
1044         unsigned int bits;
1045         int state;
1046 
1047         spin_lock(&osb->osb_lock);
1048         if (osb->local_alloc_state == OCFS2_LA_DISABLED) {
1049                 WARN_ON_ONCE(osb->local_alloc_state == OCFS2_LA_DISABLED);
1050                 goto out_unlock;
1051         }
1052 
1053         /*
1054          * ENOSPC and fragmentation are treated similarly for now.
1055          */
1056         if (event == OCFS2_LA_EVENT_ENOSPC ||
1057             event == OCFS2_LA_EVENT_FRAGMENTED) {
1058                 /*
1059                  * We ran out of contiguous space in the primary
1060                  * bitmap. Drastically reduce the number of bits used
1061                  * by local alloc until we have to disable it.
1062                  */
1063                 bits = osb->local_alloc_bits >> 1;
1064                 if (bits > ocfs2_megabytes_to_clusters(osb->sb, 1)) {
1065                         /*
1066                          * By setting state to THROTTLED, we'll keep
1067                          * the number of local alloc bits used down
1068                          * until an event occurs which would give us
1069                          * reason to assume the bitmap situation might
1070                          * have changed.
1071                          */
1072                         osb->local_alloc_state = OCFS2_LA_THROTTLED;
1073                         osb->local_alloc_bits = bits;
1074                 } else {
1075                         osb->local_alloc_state = OCFS2_LA_DISABLED;
1076                 }
1077                 queue_delayed_work(osb->ocfs2_wq, &osb->la_enable_wq,
1078                                    OCFS2_LA_ENABLE_INTERVAL);
1079                 goto out_unlock;
1080         }
1081 
1082         /*
1083          * Don't increase the size of the local alloc window until we
1084          * know we might be able to fulfill the request. Otherwise, we
1085          * risk bouncing around the global bitmap during periods of
1086          * low space.
1087          */
1088         if (osb->local_alloc_state != OCFS2_LA_THROTTLED)
1089                 osb->local_alloc_bits = osb->local_alloc_default_bits;
1090 
1091 out_unlock:
1092         state = osb->local_alloc_state;
1093         spin_unlock(&osb->osb_lock);
1094 
1095         return state;
1096 }
1097 
1098 static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
1099                                                 struct ocfs2_alloc_context **ac,
1100                                                 struct inode **bitmap_inode,
1101                                                 struct buffer_head **bitmap_bh)
1102 {
1103         int status;
1104 
1105         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1106         if (!(*ac)) {
1107                 status = -ENOMEM;
1108                 mlog_errno(status);
1109                 goto bail;
1110         }
1111 
1112 retry_enospc:
1113         (*ac)->ac_bits_wanted = osb->local_alloc_bits;
1114         status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1115         if (status == -ENOSPC) {
1116                 if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_ENOSPC) ==
1117                     OCFS2_LA_DISABLED)
1118                         goto bail;
1119 
1120                 ocfs2_free_ac_resource(*ac);
1121                 memset(*ac, 0, sizeof(struct ocfs2_alloc_context));
1122                 goto retry_enospc;
1123         }
1124         if (status < 0) {
1125                 mlog_errno(status);
1126                 goto bail;
1127         }
1128 
1129         *bitmap_inode = (*ac)->ac_inode;
1130         igrab(*bitmap_inode);
1131         *bitmap_bh = (*ac)->ac_bh;
1132         get_bh(*bitmap_bh);
1133         status = 0;
1134 bail:
1135         if ((status < 0) && *ac) {
1136                 ocfs2_free_alloc_context(*ac);
1137                 *ac = NULL;
1138         }
1139 
1140         if (status)
1141                 mlog_errno(status);
1142         return status;
1143 }
1144 
1145 /*
1146  * pass it the bitmap lock in lock_bh if you have it.
1147  */
1148 static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
1149                                         handle_t *handle,
1150                                         struct ocfs2_alloc_context *ac)
1151 {
1152         int status = 0;
1153         u32 cluster_off, cluster_count;
1154         struct ocfs2_dinode *alloc = NULL;
1155         struct ocfs2_local_alloc *la;
1156 
1157         alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1158         la = OCFS2_LOCAL_ALLOC(alloc);
1159 
1160         trace_ocfs2_local_alloc_new_window(
1161                 le32_to_cpu(alloc->id1.bitmap1.i_total),
1162                 osb->local_alloc_bits);
1163 
1164         /* Instruct the allocation code to try the most recently used
1165          * cluster group. We'll re-record the group used this pass
1166          * below. */
1167         ac->ac_last_group = osb->la_last_gd;
1168 
1169         /* we used the generic suballoc reserve function, but we set
1170          * everything up nicely, so there's no reason why we can't use
1171          * the more specific cluster api to claim bits. */
1172         status = ocfs2_claim_clusters(handle, ac, osb->local_alloc_bits,
1173                                       &cluster_off, &cluster_count);
1174         if (status == -ENOSPC) {
1175 retry_enospc:
1176                 /*
1177                  * Note: We could also try syncing the journal here to
1178                  * allow use of any free bits which the current
1179                  * transaction can't give us access to. --Mark
1180                  */
1181                 if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_FRAGMENTED) ==
1182                     OCFS2_LA_DISABLED)
1183                         goto bail;
1184 
1185                 ac->ac_bits_wanted = osb->local_alloc_bits;
1186                 status = ocfs2_claim_clusters(handle, ac,
1187                                               osb->local_alloc_bits,
1188                                               &cluster_off,
1189                                               &cluster_count);
1190                 if (status == -ENOSPC)
1191                         goto retry_enospc;
1192                 /*
1193                  * We only shrunk the *minimum* number of in our
1194                  * request - it's entirely possible that the allocator
1195                  * might give us more than we asked for.
1196                  */
1197                 if (status == 0) {
1198                         spin_lock(&osb->osb_lock);
1199                         osb->local_alloc_bits = cluster_count;
1200                         spin_unlock(&osb->osb_lock);
1201                 }
1202         }
1203         if (status < 0) {
1204                 if (status != -ENOSPC)
1205                         mlog_errno(status);
1206                 goto bail;
1207         }
1208 
1209         osb->la_last_gd = ac->ac_last_group;
1210 
1211         la->la_bm_off = cpu_to_le32(cluster_off);
1212         alloc->id1.bitmap1.i_total = cpu_to_le32(cluster_count);
1213         /* just in case... In the future when we find space ourselves,
1214          * we don't have to get all contiguous -- but we'll have to
1215          * set all previously used bits in bitmap and update
1216          * la_bits_set before setting the bits in the main bitmap. */
1217         alloc->id1.bitmap1.i_used = 0;
1218         memset(OCFS2_LOCAL_ALLOC(alloc)->la_bitmap, 0,
1219                le16_to_cpu(la->la_size));
1220 
1221         ocfs2_resmap_restart(&osb->osb_la_resmap, cluster_count,
1222                              OCFS2_LOCAL_ALLOC(alloc)->la_bitmap);
1223 
1224         trace_ocfs2_local_alloc_new_window_result(
1225                 OCFS2_LOCAL_ALLOC(alloc)->la_bm_off,
1226                 le32_to_cpu(alloc->id1.bitmap1.i_total));
1227 
1228 bail:
1229         if (status)
1230                 mlog_errno(status);
1231         return status;
1232 }
1233 
1234 /* Note that we do *NOT* lock the local alloc inode here as
1235  * it's been locked already for us. */
1236 static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
1237                                           struct inode *local_alloc_inode)
1238 {
1239         int status = 0;
1240         struct buffer_head *main_bm_bh = NULL;
1241         struct inode *main_bm_inode = NULL;
1242         handle_t *handle = NULL;
1243         struct ocfs2_dinode *alloc;
1244         struct ocfs2_dinode *alloc_copy = NULL;
1245         struct ocfs2_alloc_context *ac = NULL;
1246 
1247         ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_SLIDE);
1248 
1249         /* This will lock the main bitmap for us. */
1250         status = ocfs2_local_alloc_reserve_for_window(osb,
1251                                                       &ac,
1252                                                       &main_bm_inode,
1253                                                       &main_bm_bh);
1254         if (status < 0) {
1255                 if (status != -ENOSPC)
1256                         mlog_errno(status);
1257                 goto bail;
1258         }
1259 
1260         handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
1261         if (IS_ERR(handle)) {
1262                 status = PTR_ERR(handle);
1263                 handle = NULL;
1264                 mlog_errno(status);
1265                 goto bail;
1266         }
1267 
1268         alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1269 
1270         /* We want to clear the local alloc before doing anything
1271          * else, so that if we error later during this operation,
1272          * local alloc shutdown won't try to double free main bitmap
1273          * bits. Make a copy so the sync function knows which bits to
1274          * free. */
1275         alloc_copy = kmemdup(alloc, osb->local_alloc_bh->b_size, GFP_NOFS);
1276         if (!alloc_copy) {
1277                 status = -ENOMEM;
1278                 mlog_errno(status);
1279                 goto bail;
1280         }
1281 
1282         status = ocfs2_journal_access_di(handle,
1283                                          INODE_CACHE(local_alloc_inode),
1284                                          osb->local_alloc_bh,
1285                                          OCFS2_JOURNAL_ACCESS_WRITE);
1286         if (status < 0) {
1287                 mlog_errno(status);
1288                 goto bail;
1289         }
1290 
1291         ocfs2_clear_local_alloc(alloc);
1292         ocfs2_journal_dirty(handle, osb->local_alloc_bh);
1293 
1294         status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
1295                                           main_bm_inode, main_bm_bh);
1296         if (status < 0) {
1297                 mlog_errno(status);
1298                 goto bail;
1299         }
1300 
1301         status = ocfs2_local_alloc_new_window(osb, handle, ac);
1302         if (status < 0) {
1303                 if (status != -ENOSPC)
1304                         mlog_errno(status);
1305                 goto bail;
1306         }
1307 
1308         atomic_inc(&osb->alloc_stats.moves);
1309 
1310 bail:
1311         if (handle)
1312                 ocfs2_commit_trans(osb, handle);
1313 
1314         brelse(main_bm_bh);
1315 
1316         iput(main_bm_inode);
1317         kfree(alloc_copy);
1318 
1319         if (ac)
1320                 ocfs2_free_alloc_context(ac);
1321 
1322         if (status)
1323                 mlog_errno(status);
1324         return status;
1325 }
1326
/* [<][>][^][v][top][bottom][index][help] */
root/fs/ocfs2/localalloc.c

DEFINITIONS
