root/fs/xfs/xfs_trans.c

DEFINITIONS

1. xfs_trans_trace_reservations
2. xfs_trans_init
3. xfs_trans_free
4. xfs_trans_dup
5. xfs_trans_reserve
6. xfs_trans_alloc
7. xfs_trans_alloc_empty
8. xfs_trans_mod_sb
9. xfs_trans_apply_sb_deltas
10. xfs_sb_mod8
11. xfs_sb_mod32
12. xfs_sb_mod64
13. xfs_trans_unreserve_and_mod_sb
14. xfs_trans_add_item
15. xfs_trans_del_item
16. xfs_trans_free_items
17. xfs_log_item_batch_insert
18. xfs_trans_committed_bulk
19. __xfs_trans_commit
20. xfs_trans_commit
21. xfs_trans_cancel
22. xfs_trans_roll

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
   4  * Copyright (C) 2010 Red Hat, Inc.
   5  * All Rights Reserved.
   6  */
   7 #include "xfs.h"
   8 #include "xfs_fs.h"
   9 #include "xfs_shared.h"
  10 #include "xfs_format.h"
  11 #include "xfs_log_format.h"
  12 #include "xfs_trans_resv.h"
  13 #include "xfs_mount.h"
  14 #include "xfs_extent_busy.h"
  15 #include "xfs_quota.h"
  16 #include "xfs_trans.h"
  17 #include "xfs_trans_priv.h"
  18 #include "xfs_log.h"
  19 #include "xfs_trace.h"
  20 #include "xfs_error.h"
  21 #include "xfs_defer.h"
  22 
  23 kmem_zone_t     *xfs_trans_zone;
  24 
  25 #if defined(CONFIG_TRACEPOINTS)
  26 static void
  27 xfs_trans_trace_reservations(
  28         struct xfs_mount        *mp)
  29 {
  30         struct xfs_trans_res    resv;
  31         struct xfs_trans_res    *res;
  32         struct xfs_trans_res    *end_res;
  33         int                     i;
  34 
  35         res = (struct xfs_trans_res *)M_RES(mp);
  36         end_res = (struct xfs_trans_res *)(M_RES(mp) + 1);
  37         for (i = 0; res < end_res; i++, res++)
  38                 trace_xfs_trans_resv_calc(mp, i, res);
  39         xfs_log_get_max_trans_res(mp, &resv);
  40         trace_xfs_trans_resv_calc(mp, -1, &resv);
  41 }
  42 #else
  43 # define xfs_trans_trace_reservations(mp)
  44 #endif
  45 
  46 /*
  47  * Initialize the precomputed transaction reservation values
  48  * in the mount structure.
  49  */
  50 void
  51 xfs_trans_init(
  52         struct xfs_mount        *mp)
  53 {
  54         xfs_trans_resv_calc(mp, M_RES(mp));
  55         xfs_trans_trace_reservations(mp);
  56 }
  57 
  58 /*
  59  * Free the transaction structure.  If there is more clean up
  60  * to do when the structure is freed, add it here.
  61  */
  62 STATIC void
  63 xfs_trans_free(
  64         struct xfs_trans        *tp)
  65 {
  66         xfs_extent_busy_sort(&tp->t_busy);
  67         xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false);
  68 
  69         trace_xfs_trans_free(tp, _RET_IP_);
  70         atomic_dec(&tp->t_mountp->m_active_trans);
  71         if (!(tp->t_flags & XFS_TRANS_NO_WRITECOUNT))
  72                 sb_end_intwrite(tp->t_mountp->m_super);
  73         xfs_trans_free_dqinfo(tp);
  74         kmem_zone_free(xfs_trans_zone, tp);
  75 }
  76 
  77 /*
  78  * This is called to create a new transaction which will share the
  79  * permanent log reservation of the given transaction.  The remaining
  80  * unused block and rt extent reservations are also inherited.  This
  81  * implies that the original transaction is no longer allowed to allocate
  82  * blocks.  Locks and log items, however, are no inherited.  They must
  83  * be added to the new transaction explicitly.
  84  */
  85 STATIC struct xfs_trans *
  86 xfs_trans_dup(
  87         struct xfs_trans        *tp)
  88 {
  89         struct xfs_trans        *ntp;
  90 
  91         trace_xfs_trans_dup(tp, _RET_IP_);
  92 
  93         ntp = kmem_zone_zalloc(xfs_trans_zone, 0);
  94 
  95         /*
  96          * Initialize the new transaction structure.
  97          */
  98         ntp->t_magic = XFS_TRANS_HEADER_MAGIC;
  99         ntp->t_mountp = tp->t_mountp;
 100         INIT_LIST_HEAD(&ntp->t_items);
 101         INIT_LIST_HEAD(&ntp->t_busy);
 102         INIT_LIST_HEAD(&ntp->t_dfops);
 103         ntp->t_firstblock = NULLFSBLOCK;
 104 
 105         ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
 106         ASSERT(tp->t_ticket != NULL);
 107 
 108         ntp->t_flags = XFS_TRANS_PERM_LOG_RES |
 109                        (tp->t_flags & XFS_TRANS_RESERVE) |
 110                        (tp->t_flags & XFS_TRANS_NO_WRITECOUNT);
 111         /* We gave our writer reference to the new transaction */
 112         tp->t_flags |= XFS_TRANS_NO_WRITECOUNT;
 113         ntp->t_ticket = xfs_log_ticket_get(tp->t_ticket);
 114 
 115         ASSERT(tp->t_blk_res >= tp->t_blk_res_used);
 116         ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
 117         tp->t_blk_res = tp->t_blk_res_used;
 118 
 119         ntp->t_rtx_res = tp->t_rtx_res - tp->t_rtx_res_used;
 120         tp->t_rtx_res = tp->t_rtx_res_used;
 121         ntp->t_pflags = tp->t_pflags;
 122 
 123         /* move deferred ops over to the new tp */
 124         xfs_defer_move(ntp, tp);
 125 
 126         xfs_trans_dup_dqinfo(tp, ntp);
 127 
 128         atomic_inc(&tp->t_mountp->m_active_trans);
 129         return ntp;
 130 }
 131 
 132 /*
 133  * This is called to reserve free disk blocks and log space for the
 134  * given transaction.  This must be done before allocating any resources
 135  * within the transaction.
 136  *
 137  * This will return ENOSPC if there are not enough blocks available.
 138  * It will sleep waiting for available log space.
 139  * The only valid value for the flags parameter is XFS_RES_LOG_PERM, which
 140  * is used by long running transactions.  If any one of the reservations
 141  * fails then they will all be backed out.
 142  *
 143  * This does not do quota reservations. That typically is done by the
 144  * caller afterwards.
 145  */
 146 static int
 147 xfs_trans_reserve(
 148         struct xfs_trans        *tp,
 149         struct xfs_trans_res    *resp,
 150         uint                    blocks,
 151         uint                    rtextents)
 152 {
 153         int             error = 0;
 154         bool            rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
 155 
 156         /* Mark this thread as being in a transaction */
 157         current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
 158 
 159         /*
 160          * Attempt to reserve the needed disk blocks by decrementing
 161          * the number needed from the number available.  This will
 162          * fail if the count would go below zero.
 163          */
 164         if (blocks > 0) {
 165                 error = xfs_mod_fdblocks(tp->t_mountp, -((int64_t)blocks), rsvd);
 166                 if (error != 0) {
 167                         current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
 168                         return -ENOSPC;
 169                 }
 170                 tp->t_blk_res += blocks;
 171         }
 172 
 173         /*
 174          * Reserve the log space needed for this transaction.
 175          */
 176         if (resp->tr_logres > 0) {
 177                 bool    permanent = false;
 178 
 179                 ASSERT(tp->t_log_res == 0 ||
 180                        tp->t_log_res == resp->tr_logres);
 181                 ASSERT(tp->t_log_count == 0 ||
 182                        tp->t_log_count == resp->tr_logcount);
 183 
 184                 if (resp->tr_logflags & XFS_TRANS_PERM_LOG_RES) {
 185                         tp->t_flags |= XFS_TRANS_PERM_LOG_RES;
 186                         permanent = true;
 187                 } else {
 188                         ASSERT(tp->t_ticket == NULL);
 189                         ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
 190                 }
 191 
 192                 if (tp->t_ticket != NULL) {
 193                         ASSERT(resp->tr_logflags & XFS_TRANS_PERM_LOG_RES);
 194                         error = xfs_log_regrant(tp->t_mountp, tp->t_ticket);
 195                 } else {
 196                         error = xfs_log_reserve(tp->t_mountp,
 197                                                 resp->tr_logres,
 198                                                 resp->tr_logcount,
 199                                                 &tp->t_ticket, XFS_TRANSACTION,
 200                                                 permanent);
 201                 }
 202 
 203                 if (error)
 204                         goto undo_blocks;
 205 
 206                 tp->t_log_res = resp->tr_logres;
 207                 tp->t_log_count = resp->tr_logcount;
 208         }
 209 
 210         /*
 211          * Attempt to reserve the needed realtime extents by decrementing
 212          * the number needed from the number available.  This will
 213          * fail if the count would go below zero.
 214          */
 215         if (rtextents > 0) {
 216                 error = xfs_mod_frextents(tp->t_mountp, -((int64_t)rtextents));
 217                 if (error) {
 218                         error = -ENOSPC;
 219                         goto undo_log;
 220                 }
 221                 tp->t_rtx_res += rtextents;
 222         }
 223 
 224         return 0;
 225 
 226         /*
 227          * Error cases jump to one of these labels to undo any
 228          * reservations which have already been performed.
 229          */
 230 undo_log:
 231         if (resp->tr_logres > 0) {
 232                 xfs_log_done(tp->t_mountp, tp->t_ticket, NULL, false);
 233                 tp->t_ticket = NULL;
 234                 tp->t_log_res = 0;
 235                 tp->t_flags &= ~XFS_TRANS_PERM_LOG_RES;
 236         }
 237 
 238 undo_blocks:
 239         if (blocks > 0) {
 240                 xfs_mod_fdblocks(tp->t_mountp, (int64_t)blocks, rsvd);
 241                 tp->t_blk_res = 0;
 242         }
 243 
 244         current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
 245 
 246         return error;
 247 }
 248 
 249 int
 250 xfs_trans_alloc(
 251         struct xfs_mount        *mp,
 252         struct xfs_trans_res    *resp,
 253         uint                    blocks,
 254         uint                    rtextents,
 255         uint                    flags,
 256         struct xfs_trans        **tpp)
 257 {
 258         struct xfs_trans        *tp;
 259         int                     error;
 260 
 261         /*
 262          * Allocate the handle before we do our freeze accounting and setting up
 263          * GFP_NOFS allocation context so that we avoid lockdep false positives
 264          * by doing GFP_KERNEL allocations inside sb_start_intwrite().
 265          */
 266         tp = kmem_zone_zalloc(xfs_trans_zone, 0);
 267         if (!(flags & XFS_TRANS_NO_WRITECOUNT))
 268                 sb_start_intwrite(mp->m_super);
 269 
 270         /*
 271          * Zero-reservation ("empty") transactions can't modify anything, so
 272          * they're allowed to run while we're frozen.
 273          */
 274         WARN_ON(resp->tr_logres > 0 &&
 275                 mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
 276         atomic_inc(&mp->m_active_trans);
 277 
 278         tp->t_magic = XFS_TRANS_HEADER_MAGIC;
 279         tp->t_flags = flags;
 280         tp->t_mountp = mp;
 281         INIT_LIST_HEAD(&tp->t_items);
 282         INIT_LIST_HEAD(&tp->t_busy);
 283         INIT_LIST_HEAD(&tp->t_dfops);
 284         tp->t_firstblock = NULLFSBLOCK;
 285 
 286         error = xfs_trans_reserve(tp, resp, blocks, rtextents);
 287         if (error) {
 288                 xfs_trans_cancel(tp);
 289                 return error;
 290         }
 291 
 292         trace_xfs_trans_alloc(tp, _RET_IP_);
 293 
 294         *tpp = tp;
 295         return 0;
 296 }
 297 
 298 /*
 299  * Create an empty transaction with no reservation.  This is a defensive
 300  * mechanism for routines that query metadata without actually modifying
 301  * them -- if the metadata being queried is somehow cross-linked (think a
 302  * btree block pointer that points higher in the tree), we risk deadlock.
 303  * However, blocks grabbed as part of a transaction can be re-grabbed.
 304  * The verifiers will notice the corrupt block and the operation will fail
 305  * back to userspace without deadlocking.
 306  *
 307  * Note the zero-length reservation; this transaction MUST be cancelled
 308  * without any dirty data.
 309  */
 310 int
 311 xfs_trans_alloc_empty(
 312         struct xfs_mount                *mp,
 313         struct xfs_trans                **tpp)
 314 {
 315         struct xfs_trans_res            resv = {0};
 316 
 317         return xfs_trans_alloc(mp, &resv, 0, 0, XFS_TRANS_NO_WRITECOUNT, tpp);
 318 }
 319 
 320 /*
 321  * Record the indicated change to the given field for application
 322  * to the file system's superblock when the transaction commits.
 323  * For now, just store the change in the transaction structure.
 324  *
 325  * Mark the transaction structure to indicate that the superblock
 326  * needs to be updated before committing.
 327  *
 328  * Because we may not be keeping track of allocated/free inodes and
 329  * used filesystem blocks in the superblock, we do not mark the
 330  * superblock dirty in this transaction if we modify these fields.
 331  * We still need to update the transaction deltas so that they get
 332  * applied to the incore superblock, but we don't want them to
 333  * cause the superblock to get locked and logged if these are the
 334  * only fields in the superblock that the transaction modifies.
 335  */
 336 void
 337 xfs_trans_mod_sb(
 338         xfs_trans_t     *tp,
 339         uint            field,
 340         int64_t         delta)
 341 {
 342         uint32_t        flags = (XFS_TRANS_DIRTY|XFS_TRANS_SB_DIRTY);
 343         xfs_mount_t     *mp = tp->t_mountp;
 344 
 345         switch (field) {
 346         case XFS_TRANS_SB_ICOUNT:
 347                 tp->t_icount_delta += delta;
 348                 if (xfs_sb_version_haslazysbcount(&mp->m_sb))
 349                         flags &= ~XFS_TRANS_SB_DIRTY;
 350                 break;
 351         case XFS_TRANS_SB_IFREE:
 352                 tp->t_ifree_delta += delta;
 353                 if (xfs_sb_version_haslazysbcount(&mp->m_sb))
 354                         flags &= ~XFS_TRANS_SB_DIRTY;
 355                 break;
 356         case XFS_TRANS_SB_FDBLOCKS:
 357                 /*
 358                  * Track the number of blocks allocated in the transaction.
 359                  * Make sure it does not exceed the number reserved. If so,
 360                  * shutdown as this can lead to accounting inconsistency.
 361                  */
 362                 if (delta < 0) {
 363                         tp->t_blk_res_used += (uint)-delta;
 364                         if (tp->t_blk_res_used > tp->t_blk_res)
 365                                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
 366                 }
 367                 tp->t_fdblocks_delta += delta;
 368                 if (xfs_sb_version_haslazysbcount(&mp->m_sb))
 369                         flags &= ~XFS_TRANS_SB_DIRTY;
 370                 break;
 371         case XFS_TRANS_SB_RES_FDBLOCKS:
 372                 /*
 373                  * The allocation has already been applied to the
 374                  * in-core superblock's counter.  This should only
 375                  * be applied to the on-disk superblock.
 376                  */
 377                 tp->t_res_fdblocks_delta += delta;
 378                 if (xfs_sb_version_haslazysbcount(&mp->m_sb))
 379                         flags &= ~XFS_TRANS_SB_DIRTY;
 380                 break;
 381         case XFS_TRANS_SB_FREXTENTS:
 382                 /*
 383                  * Track the number of blocks allocated in the
 384                  * transaction.  Make sure it does not exceed the
 385                  * number reserved.
 386                  */
 387                 if (delta < 0) {
 388                         tp->t_rtx_res_used += (uint)-delta;
 389                         ASSERT(tp->t_rtx_res_used <= tp->t_rtx_res);
 390                 }
 391                 tp->t_frextents_delta += delta;
 392                 break;
 393         case XFS_TRANS_SB_RES_FREXTENTS:
 394                 /*
 395                  * The allocation has already been applied to the
 396                  * in-core superblock's counter.  This should only
 397                  * be applied to the on-disk superblock.
 398                  */
 399                 ASSERT(delta < 0);
 400                 tp->t_res_frextents_delta += delta;
 401                 break;
 402         case XFS_TRANS_SB_DBLOCKS:
 403                 ASSERT(delta > 0);
 404                 tp->t_dblocks_delta += delta;
 405                 break;
 406         case XFS_TRANS_SB_AGCOUNT:
 407                 ASSERT(delta > 0);
 408                 tp->t_agcount_delta += delta;
 409                 break;
 410         case XFS_TRANS_SB_IMAXPCT:
 411                 tp->t_imaxpct_delta += delta;
 412                 break;
 413         case XFS_TRANS_SB_REXTSIZE:
 414                 tp->t_rextsize_delta += delta;
 415                 break;
 416         case XFS_TRANS_SB_RBMBLOCKS:
 417                 tp->t_rbmblocks_delta += delta;
 418                 break;
 419         case XFS_TRANS_SB_RBLOCKS:
 420                 tp->t_rblocks_delta += delta;
 421                 break;
 422         case XFS_TRANS_SB_REXTENTS:
 423                 tp->t_rextents_delta += delta;
 424                 break;
 425         case XFS_TRANS_SB_REXTSLOG:
 426                 tp->t_rextslog_delta += delta;
 427                 break;
 428         default:
 429                 ASSERT(0);
 430                 return;
 431         }
 432 
 433         tp->t_flags |= flags;
 434 }
 435 
 436 /*
 437  * xfs_trans_apply_sb_deltas() is called from the commit code
 438  * to bring the superblock buffer into the current transaction
 439  * and modify it as requested by earlier calls to xfs_trans_mod_sb().
 440  *
 441  * For now we just look at each field allowed to change and change
 442  * it if necessary.
 443  */
 444 STATIC void
 445 xfs_trans_apply_sb_deltas(
 446         xfs_trans_t     *tp)
 447 {
 448         xfs_dsb_t       *sbp;
 449         xfs_buf_t       *bp;
 450         int             whole = 0;
 451 
 452         bp = xfs_trans_getsb(tp, tp->t_mountp);
 453         sbp = XFS_BUF_TO_SBP(bp);
 454 
 455         /*
 456          * Check that superblock mods match the mods made to AGF counters.
 457          */
 458         ASSERT((tp->t_fdblocks_delta + tp->t_res_fdblocks_delta) ==
 459                (tp->t_ag_freeblks_delta + tp->t_ag_flist_delta +
 460                 tp->t_ag_btree_delta));
 461 
 462         /*
 463          * Only update the superblock counters if we are logging them
 464          */
 465         if (!xfs_sb_version_haslazysbcount(&(tp->t_mountp->m_sb))) {
 466                 if (tp->t_icount_delta)
 467                         be64_add_cpu(&sbp->sb_icount, tp->t_icount_delta);
 468                 if (tp->t_ifree_delta)
 469                         be64_add_cpu(&sbp->sb_ifree, tp->t_ifree_delta);
 470                 if (tp->t_fdblocks_delta)
 471                         be64_add_cpu(&sbp->sb_fdblocks, tp->t_fdblocks_delta);
 472                 if (tp->t_res_fdblocks_delta)
 473                         be64_add_cpu(&sbp->sb_fdblocks, tp->t_res_fdblocks_delta);
 474         }
 475 
 476         if (tp->t_frextents_delta)
 477                 be64_add_cpu(&sbp->sb_frextents, tp->t_frextents_delta);
 478         if (tp->t_res_frextents_delta)
 479                 be64_add_cpu(&sbp->sb_frextents, tp->t_res_frextents_delta);
 480 
 481         if (tp->t_dblocks_delta) {
 482                 be64_add_cpu(&sbp->sb_dblocks, tp->t_dblocks_delta);
 483                 whole = 1;
 484         }
 485         if (tp->t_agcount_delta) {
 486                 be32_add_cpu(&sbp->sb_agcount, tp->t_agcount_delta);
 487                 whole = 1;
 488         }
 489         if (tp->t_imaxpct_delta) {
 490                 sbp->sb_imax_pct += tp->t_imaxpct_delta;
 491                 whole = 1;
 492         }
 493         if (tp->t_rextsize_delta) {
 494                 be32_add_cpu(&sbp->sb_rextsize, tp->t_rextsize_delta);
 495                 whole = 1;
 496         }
 497         if (tp->t_rbmblocks_delta) {
 498                 be32_add_cpu(&sbp->sb_rbmblocks, tp->t_rbmblocks_delta);
 499                 whole = 1;
 500         }
 501         if (tp->t_rblocks_delta) {
 502                 be64_add_cpu(&sbp->sb_rblocks, tp->t_rblocks_delta);
 503                 whole = 1;
 504         }
 505         if (tp->t_rextents_delta) {
 506                 be64_add_cpu(&sbp->sb_rextents, tp->t_rextents_delta);
 507                 whole = 1;
 508         }
 509         if (tp->t_rextslog_delta) {
 510                 sbp->sb_rextslog += tp->t_rextslog_delta;
 511                 whole = 1;
 512         }
 513 
 514         xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
 515         if (whole)
 516                 /*
 517                  * Log the whole thing, the fields are noncontiguous.
 518                  */
 519                 xfs_trans_log_buf(tp, bp, 0, sizeof(xfs_dsb_t) - 1);
 520         else
 521                 /*
 522                  * Since all the modifiable fields are contiguous, we
 523                  * can get away with this.
 524                  */
 525                 xfs_trans_log_buf(tp, bp, offsetof(xfs_dsb_t, sb_icount),
 526                                   offsetof(xfs_dsb_t, sb_frextents) +
 527                                   sizeof(sbp->sb_frextents) - 1);
 528 }
 529 
 530 STATIC int
 531 xfs_sb_mod8(
 532         uint8_t                 *field,
 533         int8_t                  delta)
 534 {
 535         int8_t                  counter = *field;
 536 
 537         counter += delta;
 538         if (counter < 0) {
 539                 ASSERT(0);
 540                 return -EINVAL;
 541         }
 542         *field = counter;
 543         return 0;
 544 }
 545 
 546 STATIC int
 547 xfs_sb_mod32(
 548         uint32_t                *field,
 549         int32_t                 delta)
 550 {
 551         int32_t                 counter = *field;
 552 
 553         counter += delta;
 554         if (counter < 0) {
 555                 ASSERT(0);
 556                 return -EINVAL;
 557         }
 558         *field = counter;
 559         return 0;
 560 }
 561 
 562 STATIC int
 563 xfs_sb_mod64(
 564         uint64_t                *field,
 565         int64_t                 delta)
 566 {
 567         int64_t                 counter = *field;
 568 
 569         counter += delta;
 570         if (counter < 0) {
 571                 ASSERT(0);
 572                 return -EINVAL;
 573         }
 574         *field = counter;
 575         return 0;
 576 }
 577 
 578 /*
 579  * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations
 580  * and apply superblock counter changes to the in-core superblock.  The
 581  * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT
 582  * applied to the in-core superblock.  The idea is that that has already been
 583  * done.
 584  *
 585  * If we are not logging superblock counters, then the inode allocated/free and
 586  * used block counts are not updated in the on disk superblock. In this case,
 587  * XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
 588  * still need to update the incore superblock with the changes.
 589  */
 590 void
 591 xfs_trans_unreserve_and_mod_sb(
 592         struct xfs_trans        *tp)
 593 {
 594         struct xfs_mount        *mp = tp->t_mountp;
 595         bool                    rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
 596         int64_t                 blkdelta = 0;
 597         int64_t                 rtxdelta = 0;
 598         int64_t                 idelta = 0;
 599         int64_t                 ifreedelta = 0;
 600         int                     error;
 601 
 602         /* calculate deltas */
 603         if (tp->t_blk_res > 0)
 604                 blkdelta = tp->t_blk_res;
 605         if ((tp->t_fdblocks_delta != 0) &&
 606             (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
 607              (tp->t_flags & XFS_TRANS_SB_DIRTY)))
 608                 blkdelta += tp->t_fdblocks_delta;
 609 
 610         if (tp->t_rtx_res > 0)
 611                 rtxdelta = tp->t_rtx_res;
 612         if ((tp->t_frextents_delta != 0) &&
 613             (tp->t_flags & XFS_TRANS_SB_DIRTY))
 614                 rtxdelta += tp->t_frextents_delta;
 615 
 616         if (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
 617              (tp->t_flags & XFS_TRANS_SB_DIRTY)) {
 618                 idelta = tp->t_icount_delta;
 619                 ifreedelta = tp->t_ifree_delta;
 620         }
 621 
 622         /* apply the per-cpu counters */
 623         if (blkdelta) {
 624                 error = xfs_mod_fdblocks(mp, blkdelta, rsvd);
 625                 if (error)
 626                         goto out;
 627         }
 628 
 629         if (idelta) {
 630                 error = xfs_mod_icount(mp, idelta);
 631                 if (error)
 632                         goto out_undo_fdblocks;
 633         }
 634 
 635         if (ifreedelta) {
 636                 error = xfs_mod_ifree(mp, ifreedelta);
 637                 if (error)
 638                         goto out_undo_icount;
 639         }
 640 
 641         if (rtxdelta == 0 && !(tp->t_flags & XFS_TRANS_SB_DIRTY))
 642                 return;
 643 
 644         /* apply remaining deltas */
 645         spin_lock(&mp->m_sb_lock);
 646         if (rtxdelta) {
 647                 error = xfs_sb_mod64(&mp->m_sb.sb_frextents, rtxdelta);
 648                 if (error)
 649                         goto out_undo_ifree;
 650         }
 651 
 652         if (tp->t_dblocks_delta != 0) {
 653                 error = xfs_sb_mod64(&mp->m_sb.sb_dblocks, tp->t_dblocks_delta);
 654                 if (error)
 655                         goto out_undo_frextents;
 656         }
 657         if (tp->t_agcount_delta != 0) {
 658                 error = xfs_sb_mod32(&mp->m_sb.sb_agcount, tp->t_agcount_delta);
 659                 if (error)
 660                         goto out_undo_dblocks;
 661         }
 662         if (tp->t_imaxpct_delta != 0) {
 663                 error = xfs_sb_mod8(&mp->m_sb.sb_imax_pct, tp->t_imaxpct_delta);
 664                 if (error)
 665                         goto out_undo_agcount;
 666         }
 667         if (tp->t_rextsize_delta != 0) {
 668                 error = xfs_sb_mod32(&mp->m_sb.sb_rextsize,
 669                                      tp->t_rextsize_delta);
 670                 if (error)
 671                         goto out_undo_imaxpct;
 672         }
 673         if (tp->t_rbmblocks_delta != 0) {
 674                 error = xfs_sb_mod32(&mp->m_sb.sb_rbmblocks,
 675                                      tp->t_rbmblocks_delta);
 676                 if (error)
 677                         goto out_undo_rextsize;
 678         }
 679         if (tp->t_rblocks_delta != 0) {
 680                 error = xfs_sb_mod64(&mp->m_sb.sb_rblocks, tp->t_rblocks_delta);
 681                 if (error)
 682                         goto out_undo_rbmblocks;
 683         }
 684         if (tp->t_rextents_delta != 0) {
 685                 error = xfs_sb_mod64(&mp->m_sb.sb_rextents,
 686                                      tp->t_rextents_delta);
 687                 if (error)
 688                         goto out_undo_rblocks;
 689         }
 690         if (tp->t_rextslog_delta != 0) {
 691                 error = xfs_sb_mod8(&mp->m_sb.sb_rextslog,
 692                                      tp->t_rextslog_delta);
 693                 if (error)
 694                         goto out_undo_rextents;
 695         }
 696         spin_unlock(&mp->m_sb_lock);
 697         return;
 698 
 699 out_undo_rextents:
 700         if (tp->t_rextents_delta)
 701                 xfs_sb_mod64(&mp->m_sb.sb_rextents, -tp->t_rextents_delta);
 702 out_undo_rblocks:
 703         if (tp->t_rblocks_delta)
 704                 xfs_sb_mod64(&mp->m_sb.sb_rblocks, -tp->t_rblocks_delta);
 705 out_undo_rbmblocks:
 706         if (tp->t_rbmblocks_delta)
 707                 xfs_sb_mod32(&mp->m_sb.sb_rbmblocks, -tp->t_rbmblocks_delta);
 708 out_undo_rextsize:
 709         if (tp->t_rextsize_delta)
 710                 xfs_sb_mod32(&mp->m_sb.sb_rextsize, -tp->t_rextsize_delta);
 711 out_undo_imaxpct:
 712         if (tp->t_rextsize_delta)
 713                 xfs_sb_mod8(&mp->m_sb.sb_imax_pct, -tp->t_imaxpct_delta);
 714 out_undo_agcount:
 715         if (tp->t_agcount_delta)
 716                 xfs_sb_mod32(&mp->m_sb.sb_agcount, -tp->t_agcount_delta);
 717 out_undo_dblocks:
 718         if (tp->t_dblocks_delta)
 719                 xfs_sb_mod64(&mp->m_sb.sb_dblocks, -tp->t_dblocks_delta);
 720 out_undo_frextents:
 721         if (rtxdelta)
 722                 xfs_sb_mod64(&mp->m_sb.sb_frextents, -rtxdelta);
 723 out_undo_ifree:
 724         spin_unlock(&mp->m_sb_lock);
 725         if (ifreedelta)
 726                 xfs_mod_ifree(mp, -ifreedelta);
 727 out_undo_icount:
 728         if (idelta)
 729                 xfs_mod_icount(mp, -idelta);
 730 out_undo_fdblocks:
 731         if (blkdelta)
 732                 xfs_mod_fdblocks(mp, -blkdelta, rsvd);
 733 out:
 734         ASSERT(error == 0);
 735         return;
 736 }
 737 
 738 /* Add the given log item to the transaction's list of log items. */
 739 void
 740 xfs_trans_add_item(
 741         struct xfs_trans        *tp,
 742         struct xfs_log_item     *lip)
 743 {
 744         ASSERT(lip->li_mountp == tp->t_mountp);
 745         ASSERT(lip->li_ailp == tp->t_mountp->m_ail);
 746         ASSERT(list_empty(&lip->li_trans));
 747         ASSERT(!test_bit(XFS_LI_DIRTY, &lip->li_flags));
 748 
 749         list_add_tail(&lip->li_trans, &tp->t_items);
 750         trace_xfs_trans_add_item(tp, _RET_IP_);
 751 }
 752 
 753 /*
 754  * Unlink the log item from the transaction. the log item is no longer
 755  * considered dirty in this transaction, as the linked transaction has
 756  * finished, either by abort or commit completion.
 757  */
 758 void
 759 xfs_trans_del_item(
 760         struct xfs_log_item     *lip)
 761 {
 762         clear_bit(XFS_LI_DIRTY, &lip->li_flags);
 763         list_del_init(&lip->li_trans);
 764 }
 765 
 766 /* Detach and unlock all of the items in a transaction */
 767 static void
 768 xfs_trans_free_items(
 769         struct xfs_trans        *tp,
 770         bool                    abort)
 771 {
 772         struct xfs_log_item     *lip, *next;
 773 
 774         trace_xfs_trans_free_items(tp, _RET_IP_);
 775 
 776         list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
 777                 xfs_trans_del_item(lip);
 778                 if (abort)
 779                         set_bit(XFS_LI_ABORTED, &lip->li_flags);
 780                 if (lip->li_ops->iop_release)
 781                         lip->li_ops->iop_release(lip);
 782         }
 783 }
 784 
 785 static inline void
 786 xfs_log_item_batch_insert(
 787         struct xfs_ail          *ailp,
 788         struct xfs_ail_cursor   *cur,
 789         struct xfs_log_item     **log_items,
 790         int                     nr_items,
 791         xfs_lsn_t               commit_lsn)
 792 {
 793         int     i;
 794 
 795         spin_lock(&ailp->ail_lock);
 796         /* xfs_trans_ail_update_bulk drops ailp->ail_lock */
 797         xfs_trans_ail_update_bulk(ailp, cur, log_items, nr_items, commit_lsn);
 798 
 799         for (i = 0; i < nr_items; i++) {
 800                 struct xfs_log_item *lip = log_items[i];
 801 
 802                 if (lip->li_ops->iop_unpin)
 803                         lip->li_ops->iop_unpin(lip, 0);
 804         }
 805 }
 806 
 807 /*
 808  * Bulk operation version of xfs_trans_committed that takes a log vector of
 809  * items to insert into the AIL. This uses bulk AIL insertion techniques to
 810  * minimise lock traffic.
 811  *
 812  * If we are called with the aborted flag set, it is because a log write during
 813  * a CIL checkpoint commit has failed. In this case, all the items in the
 814  * checkpoint have already gone through iop_committed and iop_committing, which
 815  * means that checkpoint commit abort handling is treated exactly the same
 816  * as an iclog write error even though we haven't started any IO yet. Hence in
 817  * this case all we need to do is iop_committed processing, followed by an
 818  * iop_unpin(aborted) call.
 819  *
 820  * The AIL cursor is used to optimise the insert process. If commit_lsn is not
 821  * at the end of the AIL, the insert cursor avoids the need to walk
 822  * the AIL to find the insertion point on every xfs_log_item_batch_insert()
 823  * call. This saves a lot of needless list walking and is a net win, even
 824  * though it slightly increases that amount of AIL lock traffic to set it up
 825  * and tear it down.
 826  */
 827 void
 828 xfs_trans_committed_bulk(
 829         struct xfs_ail          *ailp,
 830         struct xfs_log_vec      *log_vector,
 831         xfs_lsn_t               commit_lsn,
 832         bool                    aborted)
 833 {
 834 #define LOG_ITEM_BATCH_SIZE     32
 835         struct xfs_log_item     *log_items[LOG_ITEM_BATCH_SIZE];
 836         struct xfs_log_vec      *lv;
 837         struct xfs_ail_cursor   cur;
 838         int                     i = 0;
 839 
 840         spin_lock(&ailp->ail_lock);
 841         xfs_trans_ail_cursor_last(ailp, &cur, commit_lsn);
 842         spin_unlock(&ailp->ail_lock);
 843 
 844         /* unpin all the log items */
 845         for (lv = log_vector; lv; lv = lv->lv_next ) {
 846                 struct xfs_log_item     *lip = lv->lv_item;
 847                 xfs_lsn_t               item_lsn;
 848 
 849                 if (aborted)
 850                         set_bit(XFS_LI_ABORTED, &lip->li_flags);
 851 
 852                 if (lip->li_ops->flags & XFS_ITEM_RELEASE_WHEN_COMMITTED) {
 853                         lip->li_ops->iop_release(lip);
 854                         continue;
 855                 }
 856 
 857                 if (lip->li_ops->iop_committed)
 858                         item_lsn = lip->li_ops->iop_committed(lip, commit_lsn);
 859                 else
 860                         item_lsn = commit_lsn;
 861 
 862                 /* item_lsn of -1 means the item needs no further processing */
 863                 if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
 864                         continue;
 865 
 866                 /*
 867                  * if we are aborting the operation, no point in inserting the
 868                  * object into the AIL as we are in a shutdown situation.
 869                  */
 870                 if (aborted) {
 871                         ASSERT(XFS_FORCED_SHUTDOWN(ailp->ail_mount));
 872                         if (lip->li_ops->iop_unpin)
 873                                 lip->li_ops->iop_unpin(lip, 1);
 874                         continue;
 875                 }
 876 
 877                 if (item_lsn != commit_lsn) {
 878 
 879                         /*
 880                          * Not a bulk update option due to unusual item_lsn.
 881                          * Push into AIL immediately, rechecking the lsn once
 882                          * we have the ail lock. Then unpin the item. This does
 883                          * not affect the AIL cursor the bulk insert path is
 884                          * using.
 885                          */
 886                         spin_lock(&ailp->ail_lock);
 887                         if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0)
 888                                 xfs_trans_ail_update(ailp, lip, item_lsn);
 889                         else
 890                                 spin_unlock(&ailp->ail_lock);
 891                         if (lip->li_ops->iop_unpin)
 892                                 lip->li_ops->iop_unpin(lip, 0);
 893                         continue;
 894                 }
 895 
 896                 /* Item is a candidate for bulk AIL insert.  */
 897                 log_items[i++] = lv->lv_item;
 898                 if (i >= LOG_ITEM_BATCH_SIZE) {
 899                         xfs_log_item_batch_insert(ailp, &cur, log_items,
 900                                         LOG_ITEM_BATCH_SIZE, commit_lsn);
 901                         i = 0;
 902                 }
 903         }
 904 
 905         /* make sure we insert the remainder! */
 906         if (i)
 907                 xfs_log_item_batch_insert(ailp, &cur, log_items, i, commit_lsn);
 908 
 909         spin_lock(&ailp->ail_lock);
 910         xfs_trans_ail_cursor_done(&cur);
 911         spin_unlock(&ailp->ail_lock);
 912 }
 913 
 914 /*
 915  * Commit the given transaction to the log.
 916  *
 917  * XFS disk error handling mechanism is not based on a typical
 918  * transaction abort mechanism. Logically after the filesystem
 919  * gets marked 'SHUTDOWN', we can't let any new transactions
 920  * be durable - ie. committed to disk - because some metadata might
 921  * be inconsistent. In such cases, this returns an error, and the
 922  * caller may assume that all locked objects joined to the transaction
 923  * have already been unlocked as if the commit had succeeded.
 924  * Do not reference the transaction structure after this call.
 925  */
 926 static int
 927 __xfs_trans_commit(
 928         struct xfs_trans        *tp,
 929         bool                    regrant)
 930 {
 931         struct xfs_mount        *mp = tp->t_mountp;
 932         xfs_lsn_t               commit_lsn = -1;
 933         int                     error = 0;
 934         int                     sync = tp->t_flags & XFS_TRANS_SYNC;
 935 
 936         trace_xfs_trans_commit(tp, _RET_IP_);
 937 
 938         /*
 939          * Finish deferred items on final commit. Only permanent transactions
 940          * should ever have deferred ops.
 941          */
 942         WARN_ON_ONCE(!list_empty(&tp->t_dfops) &&
 943                      !(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
 944         if (!regrant && (tp->t_flags & XFS_TRANS_PERM_LOG_RES)) {
 945                 error = xfs_defer_finish_noroll(&tp);
 946                 if (error)
 947                         goto out_unreserve;
 948         }
 949 
 950         /*
 951          * If there is nothing to be logged by the transaction,
 952          * then unlock all of the items associated with the
 953          * transaction and free the transaction structure.
 954          * Also make sure to return any reserved blocks to
 955          * the free pool.
 956          */
 957         if (!(tp->t_flags & XFS_TRANS_DIRTY))
 958                 goto out_unreserve;
 959 
 960         if (XFS_FORCED_SHUTDOWN(mp)) {
 961                 error = -EIO;
 962                 goto out_unreserve;
 963         }
 964 
 965         ASSERT(tp->t_ticket != NULL);
 966 
 967         /*
 968          * If we need to update the superblock, then do it now.
 969          */
 970         if (tp->t_flags & XFS_TRANS_SB_DIRTY)
 971                 xfs_trans_apply_sb_deltas(tp);
 972         xfs_trans_apply_dquot_deltas(tp);
 973 
 974         xfs_log_commit_cil(mp, tp, &commit_lsn, regrant);
 975 
 976         current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
 977         xfs_trans_free(tp);
 978 
 979         /*
 980          * If the transaction needs to be synchronous, then force the
 981          * log out now and wait for it.
 982          */
 983         if (sync) {
 984                 error = xfs_log_force_lsn(mp, commit_lsn, XFS_LOG_SYNC, NULL);
 985                 XFS_STATS_INC(mp, xs_trans_sync);
 986         } else {
 987                 XFS_STATS_INC(mp, xs_trans_async);
 988         }
 989 
 990         return error;
 991 
 992 out_unreserve:
 993         xfs_trans_unreserve_and_mod_sb(tp);
 994 
 995         /*
 996          * It is indeed possible for the transaction to be not dirty but
 997          * the dqinfo portion to be.  All that means is that we have some
 998          * (non-persistent) quota reservations that need to be unreserved.
 999          */
1000         xfs_trans_unreserve_and_mod_dquots(tp);
1001         if (tp->t_ticket) {
1002                 commit_lsn = xfs_log_done(mp, tp->t_ticket, NULL, regrant);
1003                 if (commit_lsn == -1 && !error)
1004                         error = -EIO;
1005                 tp->t_ticket = NULL;
1006         }
1007         current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
1008         xfs_trans_free_items(tp, !!error);
1009         xfs_trans_free(tp);
1010 
1011         XFS_STATS_INC(mp, xs_trans_empty);
1012         return error;
1013 }
1014 
1015 int
1016 xfs_trans_commit(
1017         struct xfs_trans        *tp)
1018 {
1019         return __xfs_trans_commit(tp, false);
1020 }
1021 
1022 /*
1023  * Unlock all of the transaction's items and free the transaction.
1024  * The transaction must not have modified any of its items, because
1025  * there is no way to restore them to their previous state.
1026  *
1027  * If the transaction has made a log reservation, make sure to release
1028  * it as well.
1029  */
1030 void
1031 xfs_trans_cancel(
1032         struct xfs_trans        *tp)
1033 {
1034         struct xfs_mount        *mp = tp->t_mountp;
1035         bool                    dirty = (tp->t_flags & XFS_TRANS_DIRTY);
1036 
1037         trace_xfs_trans_cancel(tp, _RET_IP_);
1038 
1039         if (tp->t_flags & XFS_TRANS_PERM_LOG_RES)
1040                 xfs_defer_cancel(tp);
1041 
1042         /*
1043          * See if the caller is relying on us to shut down the
1044          * filesystem.  This happens in paths where we detect
1045          * corruption and decide to give up.
1046          */
1047         if (dirty && !XFS_FORCED_SHUTDOWN(mp)) {
1048                 XFS_ERROR_REPORT("xfs_trans_cancel", XFS_ERRLEVEL_LOW, mp);
1049                 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1050         }
1051 #ifdef DEBUG
1052         if (!dirty && !XFS_FORCED_SHUTDOWN(mp)) {
1053                 struct xfs_log_item *lip;
1054 
1055                 list_for_each_entry(lip, &tp->t_items, li_trans)
1056                         ASSERT(!(lip->li_type == XFS_LI_EFD));
1057         }
1058 #endif
1059         xfs_trans_unreserve_and_mod_sb(tp);
1060         xfs_trans_unreserve_and_mod_dquots(tp);
1061 
1062         if (tp->t_ticket) {
1063                 xfs_log_done(mp, tp->t_ticket, NULL, false);
1064                 tp->t_ticket = NULL;
1065         }
1066 
1067         /* mark this thread as no longer being in a transaction */
1068         current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
1069 
1070         xfs_trans_free_items(tp, dirty);
1071         xfs_trans_free(tp);
1072 }
1073 
1074 /*
1075  * Roll from one trans in the sequence of PERMANENT transactions to
1076  * the next: permanent transactions are only flushed out when
1077  * committed with xfs_trans_commit(), but we still want as soon
1078  * as possible to let chunks of it go to the log. So we commit the
1079  * chunk we've been working on and get a new transaction to continue.
1080  */
1081 int
1082 xfs_trans_roll(
1083         struct xfs_trans        **tpp)
1084 {
1085         struct xfs_trans        *trans = *tpp;
1086         struct xfs_trans_res    tres;
1087         int                     error;
1088 
1089         trace_xfs_trans_roll(trans, _RET_IP_);
1090 
1091         /*
1092          * Copy the critical parameters from one trans to the next.
1093          */
1094         tres.tr_logres = trans->t_log_res;
1095         tres.tr_logcount = trans->t_log_count;
1096 
1097         *tpp = xfs_trans_dup(trans);
1098 
1099         /*
1100          * Commit the current transaction.
1101          * If this commit failed, then it'd just unlock those items that
1102          * are not marked ihold. That also means that a filesystem shutdown
1103          * is in progress. The caller takes the responsibility to cancel
1104          * the duplicate transaction that gets returned.
1105          */
1106         error = __xfs_trans_commit(trans, true);
1107         if (error)
1108                 return error;
1109 
1110         /*
1111          * Reserve space in the log for the next transaction.
1112          * This also pushes items in the "AIL", the list of logged items,
1113          * out to disk if they are taking up space at the tail of the log
1114          * that we want to use.  This requires that either nothing be locked
1115          * across this call, or that anything that is locked be logged in
1116          * the prior and the next transactions.
1117          */
1118         tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
1119         return xfs_trans_reserve(*tpp, &tres, 0, 0);
1120 }