fs/gfs2/log.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   4  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
   5  */
   6
   7 #include <linux/sched.h>
   8 #include <linux/slab.h>
   9 #include <linux/spinlock.h>
  10 #include <linux/completion.h>
  11 #include <linux/buffer_head.h>
  12 #include <linux/gfs2_ondisk.h>
  13 #include <linux/crc32.h>
  14 #include <linux/crc32c.h>
  15 #include <linux/delay.h>
  16 #include <linux/kthread.h>
  17 #include <linux/freezer.h>
  18 #include <linux/bio.h>
  19 #include <linux/blkdev.h>
  20 #include <linux/writeback.h>
  21 #include <linux/list_sort.h>
  22
  23 #include "gfs2.h"
  24 #include "incore.h"
  25 #include "bmap.h"
  26 #include "glock.h"
  27 #include "log.h"
  28 #include "lops.h"
  29 #include "meta_io.h"
  30 #include "util.h"
  31 #include "dir.h"
  32 #include "trace_gfs2.h"
  33
  34 static void gfs2_log_shutdown(struct gfs2_sbd *sdp);
  35
  36 /**
  37  * gfs2_struct2blk - compute stuff
  38  * @sdp: the filesystem
  39  * @nstruct: the number of structures
  40  *
  41  * Compute the number of log descriptor blocks needed to hold a certain number
  42  * of structures of a certain size.
  43  *
  44  * Returns: the number of blocks needed (minimum is always 1)
  45  */
  46
  47 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct)
  48 {
  49         unsigned int blks;
  50         unsigned int first, second;
  51
  52         blks = 1;
  53         first = sdp->sd_ldptrs;
  54
  55         if (nstruct > first) {
  56                 second = sdp->sd_inptrs;
  57                 blks += DIV_ROUND_UP(nstruct - first, second);
  58         }
  59
  60         return blks;
  61 }
  62
  63 /**
  64  * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
  65  * @mapping: The associated mapping (maybe NULL)
  66  * @bd: The gfs2_bufdata to remove
  67  *
  68  * The ail lock _must_ be held when calling this function
  69  *
  70  */
  71
  72 static void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
  73 {
  74         bd->bd_tr = NULL;
  75         list_del_init(&bd->bd_ail_st_list);
  76         list_del_init(&bd->bd_ail_gl_list);
  77         atomic_dec(&bd->bd_gl->gl_ail_count);
  78         brelse(bd->bd_bh);
  79 }
  80
  81 /**
  82  * gfs2_ail1_start_one - Start I/O on a part of the AIL
  83  * @sdp: the filesystem
  84  * @wbc: The writeback control structure
  85  * @ai: The ail structure
  86  *
  87  */
  88
  89 static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
  90                                struct writeback_control *wbc,
  91                                struct gfs2_trans *tr)
  92 __releases(&sdp->sd_ail_lock)
  93 __acquires(&sdp->sd_ail_lock)
  94 {
  95         struct gfs2_glock *gl = NULL;
  96         struct address_space *mapping;
  97         struct gfs2_bufdata *bd, *s;
  98         struct buffer_head *bh;
  99         int ret = 0;
 100
 101         list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
 102                 bh = bd->bd_bh;
 103
 104                 gfs2_assert(sdp, bd->bd_tr == tr);
 105
 106                 if (!buffer_busy(bh)) {
 107                         if (buffer_uptodate(bh)) {
 108                                 list_move(&bd->bd_ail_st_list,
 109                                           &tr->tr_ail2_list);
 110                                 continue;
 111                         }
 112                         if (!cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
 113                                 gfs2_io_error_bh(sdp, bh);
 114                                 gfs2_withdraw_delayed(sdp);
 115                         }
 116                 }
 117
 118                 if (gfs2_withdrawn(sdp)) {
 119                         gfs2_remove_from_ail(bd);
 120                         continue;
 121                 }
 122                 if (!buffer_dirty(bh))
 123                         continue;
 124                 if (gl == bd->bd_gl)
 125                         continue;
 126                 gl = bd->bd_gl;
 127                 list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
 128                 mapping = bh->b_page->mapping;
 129                 if (!mapping)
 130                         continue;
 131                 spin_unlock(&sdp->sd_ail_lock);
 132                 ret = generic_writepages(mapping, wbc);
 133                 spin_lock(&sdp->sd_ail_lock);
 134                 if (ret || wbc->nr_to_write <= 0)
 135                         break;
 136                 return -EBUSY;
 137         }
 138
 139         return ret;
 140 }
 141
 142 static void dump_ail_list(struct gfs2_sbd *sdp)
 143 {
 144         struct gfs2_trans *tr;
 145         struct gfs2_bufdata *bd;
 146         struct buffer_head *bh;
 147
 148         fs_err(sdp, "Error: In gfs2_ail1_flush for ten minutes! t=%d\n",
 149                current->journal_info ? 1 : 0);
 150
 151         list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
 152                 list_for_each_entry_reverse(bd, &tr->tr_ail1_list,
 153                                             bd_ail_st_list) {
 154                         bh = bd->bd_bh;
 155                         fs_err(sdp, "bd %p: blk:0x%llx bh=%p ", bd,
 156                                (unsigned long long)bd->bd_blkno, bh);
 157                         if (!bh) {
 158                                 fs_err(sdp, "\n");
 159                                 continue;
 160                         }
 161                         fs_err(sdp, "0x%llx up2:%d dirt:%d lkd:%d req:%d "
 162                                "map:%d new:%d ar:%d aw:%d delay:%d "
 163                                "io err:%d unwritten:%d dfr:%d pin:%d esc:%d\n",
 164                                (unsigned long long)bh->b_blocknr,
 165                                buffer_uptodate(bh), buffer_dirty(bh),
 166                                buffer_locked(bh), buffer_req(bh),
 167                                buffer_mapped(bh), buffer_new(bh),
 168                                buffer_async_read(bh), buffer_async_write(bh),
 169                                buffer_delay(bh), buffer_write_io_error(bh),
 170                                buffer_unwritten(bh),
 171                                buffer_defer_completion(bh),
 172                                buffer_pinned(bh), buffer_escaped(bh));
 173                 }
 174         }
 175 }
 176
 177 /**
 178  * gfs2_ail1_flush - start writeback of some ail1 entries
 179  * @sdp: The super block
 180  * @wbc: The writeback control structure
 181  *
 182  * Writes back some ail1 entries, according to the limits in the
 183  * writeback control structure
 184  */
 185
 186 void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
 187 {
 188         struct list_head *head = &sdp->sd_ail1_list;
 189         struct gfs2_trans *tr;
 190         struct blk_plug plug;
 191         int ret;
 192         unsigned long flush_start = jiffies;
 193
 194         trace_gfs2_ail_flush(sdp, wbc, 1);
 195         blk_start_plug(&plug);
 196         spin_lock(&sdp->sd_ail_lock);
 197 restart:
 198         ret = 0;
 199         if (time_after(jiffies, flush_start + (HZ * 600))) {
 200                 dump_ail_list(sdp);
 201                 goto out;
 202         }
 203         list_for_each_entry_reverse(tr, head, tr_list) {
 204                 if (wbc->nr_to_write <= 0)
 205                         break;
 206                 ret = gfs2_ail1_start_one(sdp, wbc, tr);
 207                 if (ret) {
 208                         if (ret == -EBUSY)
 209                                 goto restart;
 210                         break;
 211                 }
 212         }
 213 out:
 214         spin_unlock(&sdp->sd_ail_lock);
 215         blk_finish_plug(&plug);
 216         if (ret) {
 217                 gfs2_lm(sdp, "gfs2_ail1_start_one (generic_writepages) "
 218                         "returned: %d\n", ret);
 219                 gfs2_withdraw(sdp);
 220         }
 221         trace_gfs2_ail_flush(sdp, wbc, 0);
 222 }
 223
 224 /**
 225  * gfs2_ail1_start - start writeback of all ail1 entries
 226  * @sdp: The superblock
 227  */
 228
 229 static void gfs2_ail1_start(struct gfs2_sbd *sdp)
 230 {
 231         struct writeback_control wbc = {
 232                 .sync_mode = WB_SYNC_NONE,
 233                 .nr_to_write = LONG_MAX,
 234                 .range_start = 0,
 235                 .range_end = LLONG_MAX,
 236         };
 237
 238         return gfs2_ail1_flush(sdp, &wbc);
 239 }
 240
 241 /**
 242  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 243  * @sdp: the filesystem
 244  * @tr: the transaction
 245  * @max_revokes: If nonzero, issue revokes for the bd items for written buffers
 246  *
 247  */
 248
 249 static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 250                                 int *max_revokes)
 251 {
 252         struct gfs2_bufdata *bd, *s;
 253         struct buffer_head *bh;
 254
 255         list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
 256                                          bd_ail_st_list) {
 257                 bh = bd->bd_bh;
 258                 gfs2_assert(sdp, bd->bd_tr == tr);
 259                 /*
 260                  * If another process flagged an io error, e.g. writing to the
 261                  * journal, error all other bhs and move them off the ail1 to
 262                  * prevent a tight loop when unmount tries to flush ail1,
 263                  * regardless of whether they're still busy. If no outside
 264                  * errors were found and the buffer is busy, move to the next.
 265                  * If the ail buffer is not busy and caught an error, flag it
 266                  * for others.
 267                  */
 268                 if (!sdp->sd_log_error && buffer_busy(bh))
 269                         continue;
 270                 if (!buffer_uptodate(bh) &&
 271                     !cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
 272                         gfs2_io_error_bh(sdp, bh);
 273                         gfs2_withdraw_delayed(sdp);
 274                 }
 275                 /*
 276                  * If we have space for revokes and the bd is no longer on any
 277                  * buf list, we can just add a revoke for it immediately and
 278                  * avoid having to put it on the ail2 list, where it would need
 279                  * to be revoked later.
 280                  */
 281                 if (*max_revokes && list_empty(&bd->bd_list)) {
 282                         gfs2_add_revoke(sdp, bd);
 283                         (*max_revokes)--;
 284                         continue;
 285                 }
 286                 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
 287         }
 288 }
 289
 290 /**
 291  * gfs2_ail1_empty - Try to empty the ail1 lists
 292  * @sdp: The superblock
 293  * @max_revokes: If non-zero, add revokes where appropriate
 294  *
 295  * Tries to empty the ail1 lists, starting with the oldest first
 296  */
 297
 298 static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes)
 299 {
 300         struct gfs2_trans *tr, *s;
 301         int oldest_tr = 1;
 302         int ret;
 303
 304         spin_lock(&sdp->sd_ail_lock);
 305         list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
 306                 gfs2_ail1_empty_one(sdp, tr, &max_revokes);
 307                 if (list_empty(&tr->tr_ail1_list) && oldest_tr)
 308                         list_move(&tr->tr_list, &sdp->sd_ail2_list);
 309                 else
 310                         oldest_tr = 0;
 311         }
 312         ret = list_empty(&sdp->sd_ail1_list);
 313         spin_unlock(&sdp->sd_ail_lock);
 314
 315         if (test_bit(SDF_WITHDRAWING, &sdp->sd_flags)) {
 316                 gfs2_lm(sdp, "fatal: I/O error(s)\n");
 317                 gfs2_withdraw(sdp);
 318         }
 319
 320         return ret;
 321 }
 322
 323 static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
 324 {
 325         struct gfs2_trans *tr;
 326         struct gfs2_bufdata *bd;
 327         struct buffer_head *bh;
 328
 329         spin_lock(&sdp->sd_ail_lock);
 330         list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
 331                 list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
 332                         bh = bd->bd_bh;
 333                         if (!buffer_locked(bh))
 334                                 continue;
 335                         get_bh(bh);
 336                         spin_unlock(&sdp->sd_ail_lock);
 337                         wait_on_buffer(bh);
 338                         brelse(bh);
 339                         return;
 340                 }
 341         }
 342         spin_unlock(&sdp->sd_ail_lock);
 343 }
 344
 345 /**
 346  * gfs2_ail_empty_tr - empty one of the ail lists for a transaction
 347  */
 348
 349 static void gfs2_ail_empty_tr(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 350                               struct list_head *head)
 351 {
 352         struct gfs2_bufdata *bd;
 353
 354         while (!list_empty(head)) {
 355                 bd = list_first_entry(head, struct gfs2_bufdata,
 356                                       bd_ail_st_list);
 357                 gfs2_assert(sdp, bd->bd_tr == tr);
 358                 gfs2_remove_from_ail(bd);
 359         }
 360 }
 361
 362 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 363 {
 364         struct gfs2_trans *tr, *safe;
 365         unsigned int old_tail = sdp->sd_log_tail;
 366         int wrap = (new_tail < old_tail);
 367         int a, b, rm;
 368
 369         spin_lock(&sdp->sd_ail_lock);
 370
 371         list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) {
 372                 a = (old_tail <= tr->tr_first);
 373                 b = (tr->tr_first < new_tail);
 374                 rm = (wrap) ? (a || b) : (a && b);
 375                 if (!rm)
 376                         continue;
 377
 378                 gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 379                 list_del(&tr->tr_list);
 380                 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
 381                 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
 382                 kfree(tr);
 383         }
 384
 385         spin_unlock(&sdp->sd_ail_lock);
 386 }
 387
 388 /**
 389  * gfs2_log_release - Release a given number of log blocks
 390  * @sdp: The GFS2 superblock
 391  * @blks: The number of blocks
 392  *
 393  */
 394
 395 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 396 {
 397
 398         atomic_add(blks, &sdp->sd_log_blks_free);
 399         trace_gfs2_log_blocks(sdp, blks);
 400         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
 401                                   sdp->sd_jdesc->jd_blocks);
 402         up_read(&sdp->sd_log_flush_lock);
 403 }
 404
 405 /**
 406  * gfs2_log_reserve - Make a log reservation
 407  * @sdp: The GFS2 superblock
 408  * @blks: The number of blocks to reserve
 409  *
 410  * Note that we never give out the last few blocks of the journal. Thats
 411  * due to the fact that there is a small number of header blocks
 412  * associated with each log flush. The exact number can't be known until
 413  * flush time, so we ensure that we have just enough free blocks at all
 414  * times to avoid running out during a log flush.
 415  *
 416  * We no longer flush the log here, instead we wake up logd to do that
 417  * for us. To avoid the thundering herd and to ensure that we deal fairly
 418  * with queued waiters, we use an exclusive wait. This means that when we
 419  * get woken with enough journal space to get our reservation, we need to
 420  * wake the next waiter on the list.
 421  *
 422  * Returns: errno
 423  */
 424
 425 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 426 {
 427         int ret = 0;
 428         unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize);
 429         unsigned wanted = blks + reserved_blks;
 430         DEFINE_WAIT(wait);
 431         int did_wait = 0;
 432         unsigned int free_blocks;
 433
 434         if (gfs2_assert_warn(sdp, blks) ||
 435             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 436                 return -EINVAL;
 437         atomic_add(blks, &sdp->sd_log_blks_needed);
 438 retry:
 439         free_blocks = atomic_read(&sdp->sd_log_blks_free);
 440         if (unlikely(free_blocks <= wanted)) {
 441                 do {
 442                         prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
 443                                         TASK_UNINTERRUPTIBLE);
 444                         wake_up(&sdp->sd_logd_waitq);
 445                         did_wait = 1;
 446                         if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
 447                                 io_schedule();
 448                         free_blocks = atomic_read(&sdp->sd_log_blks_free);
 449                 } while(free_blocks <= wanted);
 450                 finish_wait(&sdp->sd_log_waitq, &wait);
 451         }
 452         atomic_inc(&sdp->sd_reserving_log);
 453         if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
 454                                 free_blocks - blks) != free_blocks) {
 455                 if (atomic_dec_and_test(&sdp->sd_reserving_log))
 456                         wake_up(&sdp->sd_reserving_log_wait);
 457                 goto retry;
 458         }
 459         atomic_sub(blks, &sdp->sd_log_blks_needed);
 460         trace_gfs2_log_blocks(sdp, -blks);
 461
 462         /*
 463          * If we waited, then so might others, wake them up _after_ we get
 464          * our share of the log.
 465          */
 466         if (unlikely(did_wait))
 467                 wake_up(&sdp->sd_log_waitq);
 468
 469         down_read(&sdp->sd_log_flush_lock);
 470         if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
 471                 gfs2_log_release(sdp, blks);
 472                 ret = -EROFS;
 473         }
 474         if (atomic_dec_and_test(&sdp->sd_reserving_log))
 475                 wake_up(&sdp->sd_reserving_log_wait);
 476         return ret;
 477 }
 478
 479 /**
 480  * log_distance - Compute distance between two journal blocks
 481  * @sdp: The GFS2 superblock
 482  * @newer: The most recent journal block of the pair
 483  * @older: The older journal block of the pair
 484  *
 485  *   Compute the distance (in the journal direction) between two
 486  *   blocks in the journal
 487  *
 488  * Returns: the distance in blocks
 489  */
 490
 491 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 492                                         unsigned int older)
 493 {
 494         int dist;
 495
 496         dist = newer - older;
 497         if (dist < 0)
 498                 dist += sdp->sd_jdesc->jd_blocks;
 499
 500         return dist;
 501 }
 502
 503 /**
 504  * calc_reserved - Calculate the number of blocks to reserve when
 505  *                 refunding a transaction's unused buffers.
 506  * @sdp: The GFS2 superblock
 507  *
 508  * This is complex.  We need to reserve room for all our currently used
 509  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
 510  * all our journaled data buffers for journaled files (e.g. files in the
 511  * meta_fs like rindex, or files for which chattr +j was done.)
 512  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
 513  * will count it as free space (sd_log_blks_free) and corruption will follow.
 514  *
 515  * We can have metadata bufs and jdata bufs in the same journal.  So each
 516  * type gets its own log header, for which we need to reserve a block.
 517  * In fact, each type has the potential for needing more than one header
 518  * in cases where we have more buffers than will fit on a journal page.
 519  * Metadata journal entries take up half the space of journaled buffer entries.
 520  * Thus, metadata entries have buf_limit (502) and journaled buffers have
 521  * databuf_limit (251) before they cause a wrap around.
 522  *
 523  * Also, we need to reserve blocks for revoke journal entries and one for an
 524  * overall header for the lot.
 525  *
 526  * Returns: the number of blocks reserved
 527  */
 528 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 529 {
 530         unsigned int reserved = 0;
 531         unsigned int mbuf;
 532         unsigned int dbuf;
 533         struct gfs2_trans *tr = sdp->sd_log_tr;
 534
 535         if (tr) {
 536                 mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm;
 537                 dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
 538                 reserved = mbuf + dbuf;
 539                 /* Account for header blocks */
 540                 reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp));
 541                 reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp));
 542         }
 543
 544         if (sdp->sd_log_committed_revoke > 0)
 545                 reserved += gfs2_struct2blk(sdp, sdp->sd_log_committed_revoke);
 546         /* One for the overall header */
 547         if (reserved)
 548                 reserved++;
 549         return reserved;
 550 }
 551
 552 static unsigned int current_tail(struct gfs2_sbd *sdp)
 553 {
 554         struct gfs2_trans *tr;
 555         unsigned int tail;
 556
 557         spin_lock(&sdp->sd_ail_lock);
 558
 559         if (list_empty(&sdp->sd_ail1_list)) {
 560                 tail = sdp->sd_log_head;
 561         } else {
 562                 tr = list_last_entry(&sdp->sd_ail1_list, struct gfs2_trans,
 563                                 tr_list);
 564                 tail = tr->tr_first;
 565         }
 566
 567         spin_unlock(&sdp->sd_ail_lock);
 568
 569         return tail;
 570 }
 571
 572 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 573 {
 574         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 575
 576         ail2_empty(sdp, new_tail);
 577
 578         atomic_add(dist, &sdp->sd_log_blks_free);
 579         trace_gfs2_log_blocks(sdp, dist);
 580         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
 581                              sdp->sd_jdesc->jd_blocks);
 582
 583         sdp->sd_log_tail = new_tail;
 584 }
 585
 586
 587 void log_flush_wait(struct gfs2_sbd *sdp)
 588 {
 589         DEFINE_WAIT(wait);
 590
 591         if (atomic_read(&sdp->sd_log_in_flight)) {
 592                 do {
 593                         prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
 594                                         TASK_UNINTERRUPTIBLE);
 595                         if (atomic_read(&sdp->sd_log_in_flight))
 596                                 io_schedule();
 597                 } while(atomic_read(&sdp->sd_log_in_flight));
 598                 finish_wait(&sdp->sd_log_flush_wait, &wait);
 599         }
 600 }
 601
 602 static int ip_cmp(void *priv, struct list_head *a, struct list_head *b)
 603 {
 604         struct gfs2_inode *ipa, *ipb;
 605
 606         ipa = list_entry(a, struct gfs2_inode, i_ordered);
 607         ipb = list_entry(b, struct gfs2_inode, i_ordered);
 608
 609         if (ipa->i_no_addr < ipb->i_no_addr)
 610                 return -1;
 611         if (ipa->i_no_addr > ipb->i_no_addr)
 612                 return 1;
 613         return 0;
 614 }
 615
 616 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 617 {
 618         struct gfs2_inode *ip;
 619         LIST_HEAD(written);
 620
 621         spin_lock(&sdp->sd_ordered_lock);
 622         list_sort(NULL, &sdp->sd_log_ordered, &ip_cmp);
 623         while (!list_empty(&sdp->sd_log_ordered)) {
 624                 ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
 625                 if (ip->i_inode.i_mapping->nrpages == 0) {
 626                         test_and_clear_bit(GIF_ORDERED, &ip->i_flags);
 627                         list_del(&ip->i_ordered);
 628                         continue;
 629                 }
 630                 list_move(&ip->i_ordered, &written);
 631                 spin_unlock(&sdp->sd_ordered_lock);
 632                 filemap_fdatawrite(ip->i_inode.i_mapping);
 633                 spin_lock(&sdp->sd_ordered_lock);
 634         }
 635         list_splice(&written, &sdp->sd_log_ordered);
 636         spin_unlock(&sdp->sd_ordered_lock);
 637 }
 638
 639 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
 640 {
 641         struct gfs2_inode *ip;
 642
 643         spin_lock(&sdp->sd_ordered_lock);
 644         while (!list_empty(&sdp->sd_log_ordered)) {
 645                 ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
 646                 list_del(&ip->i_ordered);
 647                 WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags));
 648                 if (ip->i_inode.i_mapping->nrpages == 0)
 649                         continue;
 650                 spin_unlock(&sdp->sd_ordered_lock);
 651                 filemap_fdatawait(ip->i_inode.i_mapping);
 652                 spin_lock(&sdp->sd_ordered_lock);
 653         }
 654         spin_unlock(&sdp->sd_ordered_lock);
 655 }
 656
 657 void gfs2_ordered_del_inode(struct gfs2_inode *ip)
 658 {
 659         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 660
 661         spin_lock(&sdp->sd_ordered_lock);
 662         if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags))
 663                 list_del(&ip->i_ordered);
 664         spin_unlock(&sdp->sd_ordered_lock);
 665 }
 666
 667 void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 668 {
 669         struct buffer_head *bh = bd->bd_bh;
 670         struct gfs2_glock *gl = bd->bd_gl;
 671
 672         bh->b_private = NULL;
 673         bd->bd_blkno = bh->b_blocknr;
 674         gfs2_remove_from_ail(bd); /* drops ref on bh */
 675         bd->bd_bh = NULL;
 676         sdp->sd_log_num_revoke++;
 677         if (atomic_inc_return(&gl->gl_revokes) == 1)
 678                 gfs2_glock_hold(gl);
 679         set_bit(GLF_LFLUSH, &gl->gl_flags);
 680         list_add(&bd->bd_list, &sdp->sd_log_revokes);
 681 }
 682
 683 void gfs2_glock_remove_revoke(struct gfs2_glock *gl)
 684 {
 685         if (atomic_dec_return(&gl->gl_revokes) == 0) {
 686                 clear_bit(GLF_LFLUSH, &gl->gl_flags);
 687                 gfs2_glock_queue_put(gl);
 688         }
 689 }
 690
 691 /**
 692  * gfs2_write_revokes - Add as many revokes to the system transaction as we can
 693  * @sdp: The GFS2 superblock
 694  *
 695  * Our usual strategy is to defer writing revokes as much as we can in the hope
 696  * that we'll eventually overwrite the journal, which will make those revokes
 697  * go away.  This changes when we flush the log: at that point, there will
 698  * likely be some left-over space in the last revoke block of that transaction.
 699  * We can fill that space with additional revokes for blocks that have already
 700  * been written back.  This will basically come at no cost now, and will save
 701  * us from having to keep track of those blocks on the AIL2 list later.
 702  */
 703 void gfs2_write_revokes(struct gfs2_sbd *sdp)
 704 {
 705         /* number of revokes we still have room for */
 706         int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
 707
 708         gfs2_log_lock(sdp);
 709         while (sdp->sd_log_num_revoke > max_revokes)
 710                 max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64);
 711         max_revokes -= sdp->sd_log_num_revoke;
 712         if (!sdp->sd_log_num_revoke) {
 713                 atomic_dec(&sdp->sd_log_blks_free);
 714                 /* If no blocks have been reserved, we need to also
 715                  * reserve a block for the header */
 716                 if (!sdp->sd_log_blks_reserved)
 717                         atomic_dec(&sdp->sd_log_blks_free);
 718         }
 719         gfs2_ail1_empty(sdp, max_revokes);
 720         gfs2_log_unlock(sdp);
 721
 722         if (!sdp->sd_log_num_revoke) {
 723                 atomic_inc(&sdp->sd_log_blks_free);
 724                 if (!sdp->sd_log_blks_reserved)
 725                         atomic_inc(&sdp->sd_log_blks_free);
 726         }
 727 }
 728
 729 /**
 730  * gfs2_write_log_header - Write a journal log header buffer at lblock
 731  * @sdp: The GFS2 superblock
 732  * @jd: journal descriptor of the journal to which we are writing
 733  * @seq: sequence number
 734  * @tail: tail of the log
 735  * @lblock: value for lh_blkno (block number relative to start of journal)
 736  * @flags: log header flags GFS2_LOG_HEAD_*
 737  * @op_flags: flags to pass to the bio
 738  *
 739  * Returns: the initialized log buffer descriptor
 740  */
 741
 742 void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
 743                            u64 seq, u32 tail, u32 lblock, u32 flags,
 744                            int op_flags)
 745 {
 746         struct gfs2_log_header *lh;
 747         u32 hash, crc;
 748         struct page *page;
 749         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 750         struct timespec64 tv;
 751         struct super_block *sb = sdp->sd_vfs;
 752         u64 dblock;
 753
 754         if (gfs2_withdrawn(sdp))
 755                 goto out;
 756
 757         page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
 758         lh = page_address(page);
 759         clear_page(lh);
 760
 761         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 762         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 763         lh->lh_header.__pad0 = cpu_to_be64(0);
 764         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 765         lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
 766         lh->lh_sequence = cpu_to_be64(seq);
 767         lh->lh_flags = cpu_to_be32(flags);
 768         lh->lh_tail = cpu_to_be32(tail);
 769         lh->lh_blkno = cpu_to_be32(lblock);
 770         hash = ~crc32(~0, lh, LH_V1_SIZE);
 771         lh->lh_hash = cpu_to_be32(hash);
 772
 773         ktime_get_coarse_real_ts64(&tv);
 774         lh->lh_nsec = cpu_to_be32(tv.tv_nsec);
 775         lh->lh_sec = cpu_to_be64(tv.tv_sec);
 776         if (!list_empty(&jd->extent_list))
 777                 dblock = gfs2_log_bmap(jd, lblock);
 778         else {
 779                 int ret = gfs2_lblk_to_dblk(jd->jd_inode, lblock, &dblock);
 780                 if (gfs2_assert_withdraw(sdp, ret == 0))
 781                         return;
 782         }
 783         lh->lh_addr = cpu_to_be64(dblock);
 784         lh->lh_jinode = cpu_to_be64(GFS2_I(jd->jd_inode)->i_no_addr);
 785
 786         /* We may only write local statfs, quota, etc., when writing to our
 787            own journal. The values are left 0 when recovering a journal
 788            different from our own. */
 789         if (!(flags & GFS2_LOG_HEAD_RECOVERY)) {
 790                 lh->lh_statfs_addr =
 791                         cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr);
 792                 lh->lh_quota_addr =
 793                         cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr);
 794
 795                 spin_lock(&sdp->sd_statfs_spin);
 796                 lh->lh_local_total = cpu_to_be64(l_sc->sc_total);
 797                 lh->lh_local_free = cpu_to_be64(l_sc->sc_free);
 798                 lh->lh_local_dinodes = cpu_to_be64(l_sc->sc_dinodes);
 799                 spin_unlock(&sdp->sd_statfs_spin);
 800         }
 801
 802         BUILD_BUG_ON(offsetof(struct gfs2_log_header, lh_crc) != LH_V1_SIZE);
 803
 804         crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
 805                      sb->s_blocksize - LH_V1_SIZE - 4);
 806         lh->lh_crc = cpu_to_be32(crc);
 807
 808         gfs2_log_write(sdp, page, sb->s_blocksize, 0, dblock);
 809         gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE | op_flags);
 810 out:
 811         log_flush_wait(sdp);
 812 }
 813
 814 /**
 815  * log_write_header - Get and initialize a journal header buffer
 816  * @sdp: The GFS2 superblock
 817  * @flags: The log header flags, including log header origin
 818  *
 819  * Returns: the initialized log buffer descriptor
 820  */
 821
 822 static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
 823 {
 824         unsigned int tail;
 825         int op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC;
 826         enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
 827
 828         gfs2_assert_withdraw(sdp, (state != SFS_FROZEN));
 829         tail = current_tail(sdp);
 830
 831         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
 832                 gfs2_ordered_wait(sdp);
 833                 log_flush_wait(sdp);
 834                 op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
 835         }
 836         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 837         gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++, tail,
 838                               sdp->sd_log_flush_head, flags, op_flags);
 839         gfs2_log_incr_head(sdp);
 840
 841         if (sdp->sd_log_tail != tail)
 842                 log_pull_tail(sdp, tail);
 843 }
 844
 845 /**
 846  * ail_drain - drain the ail lists after a withdraw
 847  * @sdp: Pointer to GFS2 superblock
 848  */
 849 static void ail_drain(struct gfs2_sbd *sdp)
 850 {
 851         struct gfs2_trans *tr;
 852
 853         spin_lock(&sdp->sd_ail_lock);
 854         /*
 855          * For transactions on the sd_ail1_list we need to drain both the
 856          * ail1 and ail2 lists. That's because function gfs2_ail1_start_one
 857          * (temporarily) moves items from its tr_ail1 list to tr_ail2 list
 858          * before revokes are sent for that block. Items on the sd_ail2_list
 859          * should have already gotten beyond that point, so no need.
 860          */
 861         while (!list_empty(&sdp->sd_ail1_list)) {
 862                 tr = list_first_entry(&sdp->sd_ail1_list, struct gfs2_trans,
 863                                       tr_list);
 864                 gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail1_list);
 865                 gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 866                 list_del(&tr->tr_list);
 867                 kfree(tr);
 868         }
 869         while (!list_empty(&sdp->sd_ail2_list)) {
 870                 tr = list_first_entry(&sdp->sd_ail2_list, struct gfs2_trans,
 871                                       tr_list);
 872                 gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 873                 list_del(&tr->tr_list);
 874                 kfree(tr);
 875         }
 876         spin_unlock(&sdp->sd_ail_lock);
 877 }
 878
 879 /**
 880  * gfs2_log_flush - flush incore transaction(s)
 881  * @sdp: the filesystem
 882  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 883  * @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags
 884  *
 885  */
 886
 887 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)
 888 {
 889         struct gfs2_trans *tr = NULL;
 890         enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
 891
 892         down_write(&sdp->sd_log_flush_lock);
 893
 894         /*
 895          * Do this check while holding the log_flush_lock to prevent new
 896          * buffers from being added to the ail via gfs2_pin()
 897          */
 898         if (gfs2_withdrawn(sdp))
 899                 goto out;
 900
 901         /* Log might have been flushed while we waited for the flush lock */
 902         if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
 903                 up_write(&sdp->sd_log_flush_lock);
 904                 return;
 905         }
 906         trace_gfs2_log_flush(sdp, 1, flags);
 907
 908         if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN)
 909                 clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
 910
 911         sdp->sd_log_flush_head = sdp->sd_log_head;
 912         tr = sdp->sd_log_tr;
 913         if (tr) {
 914                 sdp->sd_log_tr = NULL;
 915                 INIT_LIST_HEAD(&tr->tr_ail1_list);
 916                 INIT_LIST_HEAD(&tr->tr_ail2_list);
 917                 tr->tr_first = sdp->sd_log_flush_head;
 918                 if (unlikely (state == SFS_FROZEN))
 919                         if (gfs2_assert_withdraw_delayed(sdp,
 920                                !tr->tr_num_buf_new && !tr->tr_num_databuf_new))
 921                                 goto out;
 922         }
 923
 924         if (unlikely(state == SFS_FROZEN))
 925                 if (gfs2_assert_withdraw_delayed(sdp, !sdp->sd_log_num_revoke))
 926                         goto out;
 927         if (gfs2_assert_withdraw_delayed(sdp,
 928                         sdp->sd_log_num_revoke == sdp->sd_log_committed_revoke))
 929                 goto out;
 930
 931         gfs2_ordered_write(sdp);
 932         if (gfs2_withdrawn(sdp))
 933                 goto out;
 934         lops_before_commit(sdp, tr);
 935         if (gfs2_withdrawn(sdp))
 936                 goto out;
 937         gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE);
 938         if (gfs2_withdrawn(sdp))
 939                 goto out;
 940
 941         if (sdp->sd_log_head != sdp->sd_log_flush_head) {
 942                 log_flush_wait(sdp);
 943                 log_write_header(sdp, flags);
 944         } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 945                 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
 946                 trace_gfs2_log_blocks(sdp, -1);
 947                 log_write_header(sdp, flags);
 948         }
 949         if (gfs2_withdrawn(sdp))
 950                 goto out;
 951         lops_after_commit(sdp, tr);
 952
 953         gfs2_log_lock(sdp);
 954         sdp->sd_log_head = sdp->sd_log_flush_head;
 955         sdp->sd_log_blks_reserved = 0;
 956         sdp->sd_log_committed_revoke = 0;
 957
 958         spin_lock(&sdp->sd_ail_lock);
 959         if (tr && !list_empty(&tr->tr_ail1_list)) {
 960                 list_add(&tr->tr_list, &sdp->sd_ail1_list);
 961                 tr = NULL;
 962         }
 963         spin_unlock(&sdp->sd_ail_lock);
 964         gfs2_log_unlock(sdp);
 965
 966         if (!(flags & GFS2_LOG_HEAD_FLUSH_NORMAL)) {
 967                 if (!sdp->sd_log_idle) {
 968                         for (;;) {
 969                                 gfs2_ail1_start(sdp);
 970                                 gfs2_ail1_wait(sdp);
 971                                 if (gfs2_ail1_empty(sdp, 0))
 972                                         break;
 973                         }
 974                         if (gfs2_withdrawn(sdp))
 975                                 goto out;
 976                         atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
 977                         trace_gfs2_log_blocks(sdp, -1);
 978                         log_write_header(sdp, flags);
 979                         sdp->sd_log_head = sdp->sd_log_flush_head;
 980                 }
 981                 if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
 982                              GFS2_LOG_HEAD_FLUSH_FREEZE))
 983                         gfs2_log_shutdown(sdp);
 984                 if (flags & GFS2_LOG_HEAD_FLUSH_FREEZE)
 985                         atomic_set(&sdp->sd_freeze_state, SFS_FROZEN);
 986         }
 987
 988 out:
 989         if (gfs2_withdrawn(sdp)) {
 990                 ail_drain(sdp); /* frees all transactions */
 991                 tr = NULL;
 992         }
 993
 994         trace_gfs2_log_flush(sdp, 0, flags);
 995         up_write(&sdp->sd_log_flush_lock);
 996
 997         kfree(tr);
 998 }
 999
1000 /**
1001  * gfs2_merge_trans - Merge a new transaction into a cached transaction
1002  * @old: Original transaction to be expanded
1003  * @new: New transaction to be merged
1004  */
1005
1006 static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new)
1007 {
1008         WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags));
1009
1010         old->tr_num_buf_new     += new->tr_num_buf_new;
1011         old->tr_num_databuf_new += new->tr_num_databuf_new;
1012         old->tr_num_buf_rm      += new->tr_num_buf_rm;
1013         old->tr_num_databuf_rm  += new->tr_num_databuf_rm;
1014         old->tr_num_revoke      += new->tr_num_revoke;
1015         old->tr_num_revoke_rm   += new->tr_num_revoke_rm;
1016
1017         list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
1018         list_splice_tail_init(&new->tr_buf, &old->tr_buf);
1019 }
1020
1021 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1022 {
1023         unsigned int reserved;
1024         unsigned int unused;
1025         unsigned int maxres;
1026
1027         gfs2_log_lock(sdp);
1028
1029         if (sdp->sd_log_tr) {
1030                 gfs2_merge_trans(sdp->sd_log_tr, tr);
1031         } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
1032                 gfs2_assert_withdraw(sdp, test_bit(TR_ALLOCED, &tr->tr_flags));
1033                 sdp->sd_log_tr = tr;
1034                 set_bit(TR_ATTACHED, &tr->tr_flags);
1035         }
1036
1037         sdp->sd_log_committed_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
1038         reserved = calc_reserved(sdp);
1039         maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
1040         gfs2_assert_withdraw(sdp, maxres >= reserved);
1041         unused = maxres - reserved;
1042         atomic_add(unused, &sdp->sd_log_blks_free);
1043         trace_gfs2_log_blocks(sdp, unused);
1044         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
1045                              sdp->sd_jdesc->jd_blocks);
1046         sdp->sd_log_blks_reserved = reserved;
1047
1048         gfs2_log_unlock(sdp);
1049 }
1050
1051 /**
1052  * gfs2_log_commit - Commit a transaction to the log
1053  * @sdp: the filesystem
1054  * @tr: the transaction
1055  *
1056  * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
1057  * or the total number of used blocks (pinned blocks plus AIL blocks)
1058  * is greater than thresh2.
1059  *
1060  * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
1061  * journal size.
1062  *
1063  * Returns: errno
1064  */
1065
1066 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1067 {
1068         log_refund(sdp, tr);
1069
1070         if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
1071             ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
1072             atomic_read(&sdp->sd_log_thresh2)))
1073                 wake_up(&sdp->sd_logd_waitq);
1074 }
1075
1076 /**
1077  * gfs2_log_shutdown - write a shutdown header into a journal
1078  * @sdp: the filesystem
1079  *
1080  */
1081
1082 static void gfs2_log_shutdown(struct gfs2_sbd *sdp)
1083 {
1084         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
1085         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
1086         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
1087
1088         sdp->sd_log_flush_head = sdp->sd_log_head;
1089
1090         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN);
1091
1092         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
1093         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
1094
1095         sdp->sd_log_head = sdp->sd_log_flush_head;
1096         sdp->sd_log_tail = sdp->sd_log_head;
1097 }
1098
1099 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
1100 {
1101         return (atomic_read(&sdp->sd_log_pinned) +
1102                 atomic_read(&sdp->sd_log_blks_needed) >=
1103                 atomic_read(&sdp->sd_log_thresh1));
1104 }
1105
1106 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
1107 {
1108         unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
1109
1110         if (test_and_clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags))
1111                 return 1;
1112
1113         return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
1114                 atomic_read(&sdp->sd_log_thresh2);
1115 }
1116
1117 /**
1118  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
1119  * @sdp: Pointer to GFS2 superblock
1120  *
1121  * Also, periodically check to make sure that we're using the most recent
1122  * journal index.
1123  */
1124
1125 int gfs2_logd(void *data)
1126 {
1127         struct gfs2_sbd *sdp = data;
1128         unsigned long t = 1;
1129         DEFINE_WAIT(wait);
1130         bool did_flush;
1131
1132         while (!kthread_should_stop()) {
1133
1134                 /* Check for errors writing to the journal */
1135                 if (sdp->sd_log_error) {
1136                         gfs2_lm(sdp,
1137                                 "GFS2: fsid=%s: error %d: "
1138                                 "withdrawing the file system to "
1139                                 "prevent further damage.\n",
1140                                 sdp->sd_fsname, sdp->sd_log_error);
1141                         gfs2_withdraw(sdp);
1142                 }
1143
1144                 did_flush = false;
1145                 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
1146                         gfs2_ail1_empty(sdp, 0);
1147                         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1148                                        GFS2_LFC_LOGD_JFLUSH_REQD);
1149                         did_flush = true;
1150                 }
1151
1152                 if (gfs2_ail_flush_reqd(sdp)) {
1153                         gfs2_ail1_start(sdp);
1154                         gfs2_ail1_wait(sdp);
1155                         gfs2_ail1_empty(sdp, 0);
1156                         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1157                                        GFS2_LFC_LOGD_AIL_FLUSH_REQD);
1158                         did_flush = true;
1159                 }
1160
1161                 if (!gfs2_ail_flush_reqd(sdp) || did_flush)
1162                         wake_up(&sdp->sd_log_waitq);
1163
1164                 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
1165
1166                 try_to_freeze();
1167
1168                 do {
1169                         prepare_to_wait(&sdp->sd_logd_waitq, &wait,
1170                                         TASK_INTERRUPTIBLE);
1171                         if (!gfs2_ail_flush_reqd(sdp) &&
1172                             !gfs2_jrnl_flush_reqd(sdp) &&
1173                             !kthread_should_stop())
1174                                 t = schedule_timeout(t);
1175                 } while(t && !gfs2_ail_flush_reqd(sdp) &&
1176                         !gfs2_jrnl_flush_reqd(sdp) &&
1177                         !kthread_should_stop());
1178                 finish_wait(&sdp->sd_logd_waitq, &wait);
1179         }
1180
1181         return 0;
1182 }
1183