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 #include "trans.h"
  34
  35 static void gfs2_log_shutdown(struct gfs2_sbd *sdp);
  36
  37 /**
  38  * gfs2_struct2blk - compute stuff
  39  * @sdp: the filesystem
  40  * @nstruct: the number of structures
  41  *
  42  * Compute the number of log descriptor blocks needed to hold a certain number
  43  * of structures of a certain size.
  44  *
  45  * Returns: the number of blocks needed (minimum is always 1)
  46  */
  47
  48 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct)
  49 {
  50         unsigned int blks;
  51         unsigned int first, second;
  52
  53         /* The initial struct gfs2_log_descriptor block */
  54         blks = 1;
  55         first = sdp->sd_ldptrs;
  56
  57         if (nstruct > first) {
  58                 /* Subsequent struct gfs2_meta_header blocks */
  59                 second = sdp->sd_inptrs;
  60                 blks += DIV_ROUND_UP(nstruct - first, second);
  61         }
  62
  63         return blks;
  64 }
  65
  66 /**
  67  * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
  68  * @bd: The gfs2_bufdata to remove
  69  *
  70  * The ail lock _must_ be held when calling this function
  71  *
  72  */
  73
  74 void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
  75 {
  76         bd->bd_tr = NULL;
  77         list_del_init(&bd->bd_ail_st_list);
  78         list_del_init(&bd->bd_ail_gl_list);
  79         atomic_dec(&bd->bd_gl->gl_ail_count);
  80         brelse(bd->bd_bh);
  81 }
  82
  83 /**
  84  * gfs2_ail1_start_one - Start I/O on a transaction
  85  * @sdp: The superblock
  86  * @wbc: The writeback control structure
  87  * @tr: The transaction to start I/O on
  88  * @plug: The block plug currently active
  89  */
  90
  91 static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
  92                                struct writeback_control *wbc,
  93                                struct gfs2_trans *tr, struct blk_plug *plug)
  94 __releases(&sdp->sd_ail_lock)
  95 __acquires(&sdp->sd_ail_lock)
  96 {
  97         struct gfs2_glock *gl = NULL;
  98         struct address_space *mapping;
  99         struct gfs2_bufdata *bd, *s;
 100         struct buffer_head *bh;
 101         int ret = 0;
 102
 103         list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
 104                 bh = bd->bd_bh;
 105
 106                 gfs2_assert(sdp, bd->bd_tr == tr);
 107
 108                 if (!buffer_busy(bh)) {
 109                         if (buffer_uptodate(bh)) {
 110                                 list_move(&bd->bd_ail_st_list,
 111                                           &tr->tr_ail2_list);
 112                                 continue;
 113                         }
 114                         if (!cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
 115                                 gfs2_io_error_bh(sdp, bh);
 116                                 gfs2_withdraw_delayed(sdp);
 117                         }
 118                 }
 119
 120                 if (gfs2_withdrawn(sdp)) {
 121                         gfs2_remove_from_ail(bd);
 122                         continue;
 123                 }
 124                 if (!buffer_dirty(bh))
 125                         continue;
 126                 if (gl == bd->bd_gl)
 127                         continue;
 128                 gl = bd->bd_gl;
 129                 list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
 130                 mapping = bh->b_page->mapping;
 131                 if (!mapping)
 132                         continue;
 133                 spin_unlock(&sdp->sd_ail_lock);
 134                 ret = filemap_fdatawrite_wbc(mapping, wbc);
 135                 if (need_resched()) {
 136                         blk_finish_plug(plug);
 137                         cond_resched();
 138                         blk_start_plug(plug);
 139                 }
 140                 spin_lock(&sdp->sd_ail_lock);
 141                 if (ret == -ENODATA) /* if a jdata write into a new hole */
 142                         ret = 0; /* ignore it */
 143                 if (ret || wbc->nr_to_write <= 0)
 144                         break;
 145                 return -EBUSY;
 146         }
 147
 148         return ret;
 149 }
 150
 151 static void dump_ail_list(struct gfs2_sbd *sdp)
 152 {
 153         struct gfs2_trans *tr;
 154         struct gfs2_bufdata *bd;
 155         struct buffer_head *bh;
 156
 157         list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
 158                 list_for_each_entry_reverse(bd, &tr->tr_ail1_list,
 159                                             bd_ail_st_list) {
 160                         bh = bd->bd_bh;
 161                         fs_err(sdp, "bd %p: blk:0x%llx bh=%p ", bd,
 162                                (unsigned long long)bd->bd_blkno, bh);
 163                         if (!bh) {
 164                                 fs_err(sdp, "\n");
 165                                 continue;
 166                         }
 167                         fs_err(sdp, "0x%llx up2:%d dirt:%d lkd:%d req:%d "
 168                                "map:%d new:%d ar:%d aw:%d delay:%d "
 169                                "io err:%d unwritten:%d dfr:%d pin:%d esc:%d\n",
 170                                (unsigned long long)bh->b_blocknr,
 171                                buffer_uptodate(bh), buffer_dirty(bh),
 172                                buffer_locked(bh), buffer_req(bh),
 173                                buffer_mapped(bh), buffer_new(bh),
 174                                buffer_async_read(bh), buffer_async_write(bh),
 175                                buffer_delay(bh), buffer_write_io_error(bh),
 176                                buffer_unwritten(bh),
 177                                buffer_defer_completion(bh),
 178                                buffer_pinned(bh), buffer_escaped(bh));
 179                 }
 180         }
 181 }
 182
 183 /**
 184  * gfs2_ail1_flush - start writeback of some ail1 entries
 185  * @sdp: The super block
 186  * @wbc: The writeback control structure
 187  *
 188  * Writes back some ail1 entries, according to the limits in the
 189  * writeback control structure
 190  */
 191
 192 void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
 193 {
 194         struct list_head *head = &sdp->sd_ail1_list;
 195         struct gfs2_trans *tr;
 196         struct blk_plug plug;
 197         int ret;
 198         unsigned long flush_start = jiffies;
 199
 200         trace_gfs2_ail_flush(sdp, wbc, 1);
 201         blk_start_plug(&plug);
 202         spin_lock(&sdp->sd_ail_lock);
 203 restart:
 204         ret = 0;
 205         if (time_after(jiffies, flush_start + (HZ * 600))) {
 206                 fs_err(sdp, "Error: In %s for ten minutes! t=%d\n",
 207                        __func__, current->journal_info ? 1 : 0);
 208                 dump_ail_list(sdp);
 209                 goto out;
 210         }
 211         list_for_each_entry_reverse(tr, head, tr_list) {
 212                 if (wbc->nr_to_write <= 0)
 213                         break;
 214                 ret = gfs2_ail1_start_one(sdp, wbc, tr, &plug);
 215                 if (ret) {
 216                         if (ret == -EBUSY)
 217                                 goto restart;
 218                         break;
 219                 }
 220         }
 221 out:
 222         spin_unlock(&sdp->sd_ail_lock);
 223         blk_finish_plug(&plug);
 224         if (ret) {
 225                 gfs2_lm(sdp, "gfs2_ail1_start_one returned: %d\n", ret);
 226                 gfs2_withdraw(sdp);
 227         }
 228         trace_gfs2_ail_flush(sdp, wbc, 0);
 229 }
 230
 231 /**
 232  * gfs2_ail1_start - start writeback of all ail1 entries
 233  * @sdp: The superblock
 234  */
 235
 236 static void gfs2_ail1_start(struct gfs2_sbd *sdp)
 237 {
 238         struct writeback_control wbc = {
 239                 .sync_mode = WB_SYNC_NONE,
 240                 .nr_to_write = LONG_MAX,
 241                 .range_start = 0,
 242                 .range_end = LLONG_MAX,
 243         };
 244
 245         return gfs2_ail1_flush(sdp, &wbc);
 246 }
 247
 248 static void gfs2_log_update_flush_tail(struct gfs2_sbd *sdp)
 249 {
 250         unsigned int new_flush_tail = sdp->sd_log_head;
 251         struct gfs2_trans *tr;
 252
 253         if (!list_empty(&sdp->sd_ail1_list)) {
 254                 tr = list_last_entry(&sdp->sd_ail1_list,
 255                                      struct gfs2_trans, tr_list);
 256                 new_flush_tail = tr->tr_first;
 257         }
 258         sdp->sd_log_flush_tail = new_flush_tail;
 259 }
 260
 261 static void gfs2_log_update_head(struct gfs2_sbd *sdp)
 262 {
 263         unsigned int new_head = sdp->sd_log_flush_head;
 264
 265         if (sdp->sd_log_flush_tail == sdp->sd_log_head)
 266                 sdp->sd_log_flush_tail = new_head;
 267         sdp->sd_log_head = new_head;
 268 }
 269
 270 /*
 271  * gfs2_ail_empty_tr - empty one of the ail lists of a transaction
 272  */
 273
 274 static void gfs2_ail_empty_tr(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 275                               struct list_head *head)
 276 {
 277         struct gfs2_bufdata *bd;
 278
 279         while (!list_empty(head)) {
 280                 bd = list_first_entry(head, struct gfs2_bufdata,
 281                                       bd_ail_st_list);
 282                 gfs2_assert(sdp, bd->bd_tr == tr);
 283                 gfs2_remove_from_ail(bd);
 284         }
 285 }
 286
 287 /**
 288  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 289  * @sdp: the filesystem
 290  * @tr: the transaction
 291  * @max_revokes: If nonzero, issue revokes for the bd items for written buffers
 292  *
 293  * returns: the transaction's count of remaining active items
 294  */
 295
 296 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 297                                 int *max_revokes)
 298 {
 299         struct gfs2_bufdata *bd, *s;
 300         struct buffer_head *bh;
 301         int active_count = 0;
 302
 303         list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
 304                                          bd_ail_st_list) {
 305                 bh = bd->bd_bh;
 306                 gfs2_assert(sdp, bd->bd_tr == tr);
 307                 /*
 308                  * If another process flagged an io error, e.g. writing to the
 309                  * journal, error all other bhs and move them off the ail1 to
 310                  * prevent a tight loop when unmount tries to flush ail1,
 311                  * regardless of whether they're still busy. If no outside
 312                  * errors were found and the buffer is busy, move to the next.
 313                  * If the ail buffer is not busy and caught an error, flag it
 314                  * for others.
 315                  */
 316                 if (!sdp->sd_log_error && buffer_busy(bh)) {
 317                         active_count++;
 318                         continue;
 319                 }
 320                 if (!buffer_uptodate(bh) &&
 321                     !cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
 322                         gfs2_io_error_bh(sdp, bh);
 323                         gfs2_withdraw_delayed(sdp);
 324                 }
 325                 /*
 326                  * If we have space for revokes and the bd is no longer on any
 327                  * buf list, we can just add a revoke for it immediately and
 328                  * avoid having to put it on the ail2 list, where it would need
 329                  * to be revoked later.
 330                  */
 331                 if (*max_revokes && list_empty(&bd->bd_list)) {
 332                         gfs2_add_revoke(sdp, bd);
 333                         (*max_revokes)--;
 334                         continue;
 335                 }
 336                 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
 337         }
 338         return active_count;
 339 }
 340
 341 /**
 342  * gfs2_ail1_empty - Try to empty the ail1 lists
 343  * @sdp: The superblock
 344  * @max_revokes: If non-zero, add revokes where appropriate
 345  *
 346  * Tries to empty the ail1 lists, starting with the oldest first
 347  */
 348
 349 static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes)
 350 {
 351         struct gfs2_trans *tr, *s;
 352         int oldest_tr = 1;
 353         int ret;
 354
 355         spin_lock(&sdp->sd_ail_lock);
 356         list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
 357                 if (!gfs2_ail1_empty_one(sdp, tr, &max_revokes) && oldest_tr)
 358                         list_move(&tr->tr_list, &sdp->sd_ail2_list);
 359                 else
 360                         oldest_tr = 0;
 361         }
 362         gfs2_log_update_flush_tail(sdp);
 363         ret = list_empty(&sdp->sd_ail1_list);
 364         spin_unlock(&sdp->sd_ail_lock);
 365
 366         if (test_bit(SDF_WITHDRAWING, &sdp->sd_flags)) {
 367                 gfs2_lm(sdp, "fatal: I/O error(s)\n");
 368                 gfs2_withdraw(sdp);
 369         }
 370
 371         return ret;
 372 }
 373
 374 static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
 375 {
 376         struct gfs2_trans *tr;
 377         struct gfs2_bufdata *bd;
 378         struct buffer_head *bh;
 379
 380         spin_lock(&sdp->sd_ail_lock);
 381         list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
 382                 list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
 383                         bh = bd->bd_bh;
 384                         if (!buffer_locked(bh))
 385                                 continue;
 386                         get_bh(bh);
 387                         spin_unlock(&sdp->sd_ail_lock);
 388                         wait_on_buffer(bh);
 389                         brelse(bh);
 390                         return;
 391                 }
 392         }
 393         spin_unlock(&sdp->sd_ail_lock);
 394 }
 395
 396 static void __ail2_empty(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 397 {
 398         gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 399         list_del(&tr->tr_list);
 400         gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
 401         gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
 402         gfs2_trans_free(sdp, tr);
 403 }
 404
 405 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 406 {
 407         struct list_head *ail2_list = &sdp->sd_ail2_list;
 408         unsigned int old_tail = sdp->sd_log_tail;
 409         struct gfs2_trans *tr, *safe;
 410
 411         spin_lock(&sdp->sd_ail_lock);
 412         if (old_tail <= new_tail) {
 413                 list_for_each_entry_safe(tr, safe, ail2_list, tr_list) {
 414                         if (old_tail <= tr->tr_first && tr->tr_first < new_tail)
 415                                 __ail2_empty(sdp, tr);
 416                 }
 417         } else {
 418                 list_for_each_entry_safe(tr, safe, ail2_list, tr_list) {
 419                         if (old_tail <= tr->tr_first || tr->tr_first < new_tail)
 420                                 __ail2_empty(sdp, tr);
 421                 }
 422         }
 423         spin_unlock(&sdp->sd_ail_lock);
 424 }
 425
 426 /**
 427  * gfs2_log_is_empty - Check if the log is empty
 428  * @sdp: The GFS2 superblock
 429  */
 430
 431 bool gfs2_log_is_empty(struct gfs2_sbd *sdp) {
 432         return atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks;
 433 }
 434
 435 static bool __gfs2_log_try_reserve_revokes(struct gfs2_sbd *sdp, unsigned int revokes)
 436 {
 437         unsigned int available;
 438
 439         available = atomic_read(&sdp->sd_log_revokes_available);
 440         while (available >= revokes) {
 441                 if (atomic_try_cmpxchg(&sdp->sd_log_revokes_available,
 442                                        &available, available - revokes))
 443                         return true;
 444         }
 445         return false;
 446 }
 447
 448 /**
 449  * gfs2_log_release_revokes - Release a given number of revokes
 450  * @sdp: The GFS2 superblock
 451  * @revokes: The number of revokes to release
 452  *
 453  * sdp->sd_log_flush_lock must be held.
 454  */
 455 void gfs2_log_release_revokes(struct gfs2_sbd *sdp, unsigned int revokes)
 456 {
 457         if (revokes)
 458                 atomic_add(revokes, &sdp->sd_log_revokes_available);
 459 }
 460
 461 /**
 462  * gfs2_log_release - Release a given number of log blocks
 463  * @sdp: The GFS2 superblock
 464  * @blks: The number of blocks
 465  *
 466  */
 467
 468 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 469 {
 470         atomic_add(blks, &sdp->sd_log_blks_free);
 471         trace_gfs2_log_blocks(sdp, blks);
 472         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
 473                                   sdp->sd_jdesc->jd_blocks);
 474         if (atomic_read(&sdp->sd_log_blks_needed))
 475                 wake_up(&sdp->sd_log_waitq);
 476 }
 477
 478 /**
 479  * __gfs2_log_try_reserve - Try to make a log reservation
 480  * @sdp: The GFS2 superblock
 481  * @blks: The number of blocks to reserve
 482  * @taboo_blks: The number of blocks to leave free
 483  *
 484  * Try to do the same as __gfs2_log_reserve(), but fail if no more log
 485  * space is immediately available.
 486  */
 487 static bool __gfs2_log_try_reserve(struct gfs2_sbd *sdp, unsigned int blks,
 488                                    unsigned int taboo_blks)
 489 {
 490         unsigned wanted = blks + taboo_blks;
 491         unsigned int free_blocks;
 492
 493         free_blocks = atomic_read(&sdp->sd_log_blks_free);
 494         while (free_blocks >= wanted) {
 495                 if (atomic_try_cmpxchg(&sdp->sd_log_blks_free, &free_blocks,
 496                                        free_blocks - blks)) {
 497                         trace_gfs2_log_blocks(sdp, -blks);
 498                         return true;
 499                 }
 500         }
 501         return false;
 502 }
 503
 504 /**
 505  * __gfs2_log_reserve - Make a log reservation
 506  * @sdp: The GFS2 superblock
 507  * @blks: The number of blocks to reserve
 508  * @taboo_blks: The number of blocks to leave free
 509  *
 510  * @taboo_blks is set to 0 for logd, and to GFS2_LOG_FLUSH_MIN_BLOCKS
 511  * for all other processes.  This ensures that when the log is almost full,
 512  * logd will still be able to call gfs2_log_flush one more time  without
 513  * blocking, which will advance the tail and make some more log space
 514  * available.
 515  *
 516  * We no longer flush the log here, instead we wake up logd to do that
 517  * for us. To avoid the thundering herd and to ensure that we deal fairly
 518  * with queued waiters, we use an exclusive wait. This means that when we
 519  * get woken with enough journal space to get our reservation, we need to
 520  * wake the next waiter on the list.
 521  */
 522
 523 static void __gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks,
 524                                unsigned int taboo_blks)
 525 {
 526         unsigned wanted = blks + taboo_blks;
 527         unsigned int free_blocks;
 528
 529         atomic_add(blks, &sdp->sd_log_blks_needed);
 530         for (;;) {
 531                 if (current != sdp->sd_logd_process)
 532                         wake_up(&sdp->sd_logd_waitq);
 533                 io_wait_event(sdp->sd_log_waitq,
 534                         (free_blocks = atomic_read(&sdp->sd_log_blks_free),
 535                          free_blocks >= wanted));
 536                 do {
 537                         if (atomic_try_cmpxchg(&sdp->sd_log_blks_free,
 538                                                &free_blocks,
 539                                                free_blocks - blks))
 540                                 goto reserved;
 541                 } while (free_blocks >= wanted);
 542         }
 543
 544 reserved:
 545         trace_gfs2_log_blocks(sdp, -blks);
 546         if (atomic_sub_return(blks, &sdp->sd_log_blks_needed))
 547                 wake_up(&sdp->sd_log_waitq);
 548 }
 549
 550 /**
 551  * gfs2_log_try_reserve - Try to make a log reservation
 552  * @sdp: The GFS2 superblock
 553  * @tr: The transaction
 554  * @extra_revokes: The number of additional revokes reserved (output)
 555  *
 556  * This is similar to gfs2_log_reserve, but sdp->sd_log_flush_lock must be
 557  * held for correct revoke accounting.
 558  */
 559
 560 bool gfs2_log_try_reserve(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 561                           unsigned int *extra_revokes)
 562 {
 563         unsigned int blks = tr->tr_reserved;
 564         unsigned int revokes = tr->tr_revokes;
 565         unsigned int revoke_blks = 0;
 566
 567         *extra_revokes = 0;
 568         if (revokes && !__gfs2_log_try_reserve_revokes(sdp, revokes)) {
 569                 revoke_blks = DIV_ROUND_UP(revokes, sdp->sd_inptrs);
 570                 *extra_revokes = revoke_blks * sdp->sd_inptrs - revokes;
 571                 blks += revoke_blks;
 572         }
 573         if (!blks)
 574                 return true;
 575         if (__gfs2_log_try_reserve(sdp, blks, GFS2_LOG_FLUSH_MIN_BLOCKS))
 576                 return true;
 577         if (!revoke_blks)
 578                 gfs2_log_release_revokes(sdp, revokes);
 579         return false;
 580 }
 581
 582 /**
 583  * gfs2_log_reserve - Make a log reservation
 584  * @sdp: The GFS2 superblock
 585  * @tr: The transaction
 586  * @extra_revokes: The number of additional revokes reserved (output)
 587  *
 588  * sdp->sd_log_flush_lock must not be held.
 589  */
 590
 591 void gfs2_log_reserve(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
 592                       unsigned int *extra_revokes)
 593 {
 594         unsigned int blks = tr->tr_reserved;
 595         unsigned int revokes = tr->tr_revokes;
 596         unsigned int revoke_blks;
 597
 598         *extra_revokes = 0;
 599         if (revokes) {
 600                 revoke_blks = DIV_ROUND_UP(revokes, sdp->sd_inptrs);
 601                 *extra_revokes = revoke_blks * sdp->sd_inptrs - revokes;
 602                 blks += revoke_blks;
 603         }
 604         __gfs2_log_reserve(sdp, blks, GFS2_LOG_FLUSH_MIN_BLOCKS);
 605 }
 606
 607 /**
 608  * log_distance - Compute distance between two journal blocks
 609  * @sdp: The GFS2 superblock
 610  * @newer: The most recent journal block of the pair
 611  * @older: The older journal block of the pair
 612  *
 613  *   Compute the distance (in the journal direction) between two
 614  *   blocks in the journal
 615  *
 616  * Returns: the distance in blocks
 617  */
 618
 619 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 620                                         unsigned int older)
 621 {
 622         int dist;
 623
 624         dist = newer - older;
 625         if (dist < 0)
 626                 dist += sdp->sd_jdesc->jd_blocks;
 627
 628         return dist;
 629 }
 630
 631 /**
 632  * calc_reserved - Calculate the number of blocks to keep reserved
 633  * @sdp: The GFS2 superblock
 634  *
 635  * This is complex.  We need to reserve room for all our currently used
 636  * metadata blocks (e.g. normal file I/O rewriting file time stamps) and
 637  * all our journaled data blocks for journaled files (e.g. files in the
 638  * meta_fs like rindex, or files for which chattr +j was done.)
 639  * If we don't reserve enough space, corruption will follow.
 640  *
 641  * We can have metadata blocks and jdata blocks in the same journal.  Each
 642  * type gets its own log descriptor, for which we need to reserve a block.
 643  * In fact, each type has the potential for needing more than one log descriptor
 644  * in cases where we have more blocks than will fit in a log descriptor.
 645  * Metadata journal entries take up half the space of journaled buffer entries.
 646  *
 647  * Also, we need to reserve blocks for revoke journal entries and one for an
 648  * overall header for the lot.
 649  *
 650  * Returns: the number of blocks reserved
 651  */
 652 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 653 {
 654         unsigned int reserved = GFS2_LOG_FLUSH_MIN_BLOCKS;
 655         unsigned int blocks;
 656         struct gfs2_trans *tr = sdp->sd_log_tr;
 657
 658         if (tr) {
 659                 blocks = tr->tr_num_buf_new - tr->tr_num_buf_rm;
 660                 reserved += blocks + DIV_ROUND_UP(blocks, buf_limit(sdp));
 661                 blocks = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
 662                 reserved += blocks + DIV_ROUND_UP(blocks, databuf_limit(sdp));
 663         }
 664         return reserved;
 665 }
 666
 667 static void log_pull_tail(struct gfs2_sbd *sdp)
 668 {
 669         unsigned int new_tail = sdp->sd_log_flush_tail;
 670         unsigned int dist;
 671
 672         if (new_tail == sdp->sd_log_tail)
 673                 return;
 674         dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 675         ail2_empty(sdp, new_tail);
 676         gfs2_log_release(sdp, dist);
 677         sdp->sd_log_tail = new_tail;
 678 }
 679
 680
 681 void log_flush_wait(struct gfs2_sbd *sdp)
 682 {
 683         DEFINE_WAIT(wait);
 684
 685         if (atomic_read(&sdp->sd_log_in_flight)) {
 686                 do {
 687                         prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
 688                                         TASK_UNINTERRUPTIBLE);
 689                         if (atomic_read(&sdp->sd_log_in_flight))
 690                                 io_schedule();
 691                 } while(atomic_read(&sdp->sd_log_in_flight));
 692                 finish_wait(&sdp->sd_log_flush_wait, &wait);
 693         }
 694 }
 695
 696 static int ip_cmp(void *priv, const struct list_head *a, const struct list_head *b)
 697 {
 698         struct gfs2_inode *ipa, *ipb;
 699
 700         ipa = list_entry(a, struct gfs2_inode, i_ordered);
 701         ipb = list_entry(b, struct gfs2_inode, i_ordered);
 702
 703         if (ipa->i_no_addr < ipb->i_no_addr)
 704                 return -1;
 705         if (ipa->i_no_addr > ipb->i_no_addr)
 706                 return 1;
 707         return 0;
 708 }
 709
 710 static void __ordered_del_inode(struct gfs2_inode *ip)
 711 {
 712         if (!list_empty(&ip->i_ordered))
 713                 list_del_init(&ip->i_ordered);
 714 }
 715
 716 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 717 {
 718         struct gfs2_inode *ip;
 719         LIST_HEAD(written);
 720
 721         spin_lock(&sdp->sd_ordered_lock);
 722         list_sort(NULL, &sdp->sd_log_ordered, &ip_cmp);
 723         while (!list_empty(&sdp->sd_log_ordered)) {
 724                 ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
 725                 if (ip->i_inode.i_mapping->nrpages == 0) {
 726                         __ordered_del_inode(ip);
 727                         continue;
 728                 }
 729                 list_move(&ip->i_ordered, &written);
 730                 spin_unlock(&sdp->sd_ordered_lock);
 731                 filemap_fdatawrite(ip->i_inode.i_mapping);
 732                 spin_lock(&sdp->sd_ordered_lock);
 733         }
 734         list_splice(&written, &sdp->sd_log_ordered);
 735         spin_unlock(&sdp->sd_ordered_lock);
 736 }
 737
 738 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
 739 {
 740         struct gfs2_inode *ip;
 741
 742         spin_lock(&sdp->sd_ordered_lock);
 743         while (!list_empty(&sdp->sd_log_ordered)) {
 744                 ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
 745                 __ordered_del_inode(ip);
 746                 if (ip->i_inode.i_mapping->nrpages == 0)
 747                         continue;
 748                 spin_unlock(&sdp->sd_ordered_lock);
 749                 filemap_fdatawait(ip->i_inode.i_mapping);
 750                 spin_lock(&sdp->sd_ordered_lock);
 751         }
 752         spin_unlock(&sdp->sd_ordered_lock);
 753 }
 754
 755 void gfs2_ordered_del_inode(struct gfs2_inode *ip)
 756 {
 757         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 758
 759         spin_lock(&sdp->sd_ordered_lock);
 760         __ordered_del_inode(ip);
 761         spin_unlock(&sdp->sd_ordered_lock);
 762 }
 763
 764 void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
 765 {
 766         struct buffer_head *bh = bd->bd_bh;
 767         struct gfs2_glock *gl = bd->bd_gl;
 768
 769         sdp->sd_log_num_revoke++;
 770         if (atomic_inc_return(&gl->gl_revokes) == 1)
 771                 gfs2_glock_hold(gl);
 772         bh->b_private = NULL;
 773         bd->bd_blkno = bh->b_blocknr;
 774         gfs2_remove_from_ail(bd); /* drops ref on bh */
 775         bd->bd_bh = NULL;
 776         set_bit(GLF_LFLUSH, &gl->gl_flags);
 777         list_add(&bd->bd_list, &sdp->sd_log_revokes);
 778 }
 779
 780 void gfs2_glock_remove_revoke(struct gfs2_glock *gl)
 781 {
 782         if (atomic_dec_return(&gl->gl_revokes) == 0) {
 783                 clear_bit(GLF_LFLUSH, &gl->gl_flags);
 784                 gfs2_glock_queue_put(gl);
 785         }
 786 }
 787
 788 /**
 789  * gfs2_flush_revokes - Add as many revokes to the system transaction as we can
 790  * @sdp: The GFS2 superblock
 791  *
 792  * Our usual strategy is to defer writing revokes as much as we can in the hope
 793  * that we'll eventually overwrite the journal, which will make those revokes
 794  * go away.  This changes when we flush the log: at that point, there will
 795  * likely be some left-over space in the last revoke block of that transaction.
 796  * We can fill that space with additional revokes for blocks that have already
 797  * been written back.  This will basically come at no cost now, and will save
 798  * us from having to keep track of those blocks on the AIL2 list later.
 799  */
 800 void gfs2_flush_revokes(struct gfs2_sbd *sdp)
 801 {
 802         /* number of revokes we still have room for */
 803         unsigned int max_revokes = atomic_read(&sdp->sd_log_revokes_available);
 804
 805         gfs2_log_lock(sdp);
 806         gfs2_ail1_empty(sdp, max_revokes);
 807         gfs2_log_unlock(sdp);
 808 }
 809
 810 /**
 811  * gfs2_write_log_header - Write a journal log header buffer at lblock
 812  * @sdp: The GFS2 superblock
 813  * @jd: journal descriptor of the journal to which we are writing
 814  * @seq: sequence number
 815  * @tail: tail of the log
 816  * @lblock: value for lh_blkno (block number relative to start of journal)
 817  * @flags: log header flags GFS2_LOG_HEAD_*
 818  * @op_flags: flags to pass to the bio
 819  *
 820  * Returns: the initialized log buffer descriptor
 821  */
 822
 823 void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
 824                            u64 seq, u32 tail, u32 lblock, u32 flags,
 825                            blk_opf_t op_flags)
 826 {
 827         struct gfs2_log_header *lh;
 828         u32 hash, crc;
 829         struct page *page;
 830         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
 831         struct timespec64 tv;
 832         struct super_block *sb = sdp->sd_vfs;
 833         u64 dblock;
 834
 835         if (gfs2_withdrawn(sdp))
 836                 return;
 837
 838         page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
 839         lh = page_address(page);
 840         clear_page(lh);
 841
 842         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 843         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 844         lh->lh_header.__pad0 = cpu_to_be64(0);
 845         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 846         lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
 847         lh->lh_sequence = cpu_to_be64(seq);
 848         lh->lh_flags = cpu_to_be32(flags);
 849         lh->lh_tail = cpu_to_be32(tail);
 850         lh->lh_blkno = cpu_to_be32(lblock);
 851         hash = ~crc32(~0, lh, LH_V1_SIZE);
 852         lh->lh_hash = cpu_to_be32(hash);
 853
 854         ktime_get_coarse_real_ts64(&tv);
 855         lh->lh_nsec = cpu_to_be32(tv.tv_nsec);
 856         lh->lh_sec = cpu_to_be64(tv.tv_sec);
 857         if (!list_empty(&jd->extent_list))
 858                 dblock = gfs2_log_bmap(jd, lblock);
 859         else {
 860                 unsigned int extlen;
 861                 int ret;
 862
 863                 extlen = 1;
 864                 ret = gfs2_get_extent(jd->jd_inode, lblock, &dblock, &extlen);
 865                 if (gfs2_assert_withdraw(sdp, ret == 0))
 866                         return;
 867         }
 868         lh->lh_addr = cpu_to_be64(dblock);
 869         lh->lh_jinode = cpu_to_be64(GFS2_I(jd->jd_inode)->i_no_addr);
 870
 871         /* We may only write local statfs, quota, etc., when writing to our
 872            own journal. The values are left 0 when recovering a journal
 873            different from our own. */
 874         if (!(flags & GFS2_LOG_HEAD_RECOVERY)) {
 875                 lh->lh_statfs_addr =
 876                         cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr);
 877                 lh->lh_quota_addr =
 878                         cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr);
 879
 880                 spin_lock(&sdp->sd_statfs_spin);
 881                 lh->lh_local_total = cpu_to_be64(l_sc->sc_total);
 882                 lh->lh_local_free = cpu_to_be64(l_sc->sc_free);
 883                 lh->lh_local_dinodes = cpu_to_be64(l_sc->sc_dinodes);
 884                 spin_unlock(&sdp->sd_statfs_spin);
 885         }
 886
 887         BUILD_BUG_ON(offsetof(struct gfs2_log_header, lh_crc) != LH_V1_SIZE);
 888
 889         crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
 890                      sb->s_blocksize - LH_V1_SIZE - 4);
 891         lh->lh_crc = cpu_to_be32(crc);
 892
 893         gfs2_log_write(sdp, jd, page, sb->s_blocksize, 0, dblock);
 894         gfs2_log_submit_bio(&jd->jd_log_bio, REQ_OP_WRITE | op_flags);
 895 }
 896
 897 /**
 898  * log_write_header - Get and initialize a journal header buffer
 899  * @sdp: The GFS2 superblock
 900  * @flags: The log header flags, including log header origin
 901  *
 902  * Returns: the initialized log buffer descriptor
 903  */
 904
 905 static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
 906 {
 907         blk_opf_t op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC;
 908         enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
 909
 910         gfs2_assert_withdraw(sdp, (state != SFS_FROZEN));
 911
 912         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
 913                 gfs2_ordered_wait(sdp);
 914                 log_flush_wait(sdp);
 915                 op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
 916         }
 917         sdp->sd_log_idle = (sdp->sd_log_flush_tail == sdp->sd_log_flush_head);
 918         gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++,
 919                               sdp->sd_log_flush_tail, sdp->sd_log_flush_head,
 920                               flags, op_flags);
 921         gfs2_log_incr_head(sdp);
 922         log_flush_wait(sdp);
 923         log_pull_tail(sdp);
 924         gfs2_log_update_head(sdp);
 925 }
 926
 927 /**
 928  * gfs2_ail_drain - drain the ail lists after a withdraw
 929  * @sdp: Pointer to GFS2 superblock
 930  */
 931 void gfs2_ail_drain(struct gfs2_sbd *sdp)
 932 {
 933         struct gfs2_trans *tr;
 934
 935         spin_lock(&sdp->sd_ail_lock);
 936         /*
 937          * For transactions on the sd_ail1_list we need to drain both the
 938          * ail1 and ail2 lists. That's because function gfs2_ail1_start_one
 939          * (temporarily) moves items from its tr_ail1 list to tr_ail2 list
 940          * before revokes are sent for that block. Items on the sd_ail2_list
 941          * should have already gotten beyond that point, so no need.
 942          */
 943         while (!list_empty(&sdp->sd_ail1_list)) {
 944                 tr = list_first_entry(&sdp->sd_ail1_list, struct gfs2_trans,
 945                                       tr_list);
 946                 gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail1_list);
 947                 gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 948                 list_del(&tr->tr_list);
 949                 gfs2_trans_free(sdp, tr);
 950         }
 951         while (!list_empty(&sdp->sd_ail2_list)) {
 952                 tr = list_first_entry(&sdp->sd_ail2_list, struct gfs2_trans,
 953                                       tr_list);
 954                 gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
 955                 list_del(&tr->tr_list);
 956                 gfs2_trans_free(sdp, tr);
 957         }
 958         gfs2_drain_revokes(sdp);
 959         spin_unlock(&sdp->sd_ail_lock);
 960 }
 961
 962 /**
 963  * empty_ail1_list - try to start IO and empty the ail1 list
 964  * @sdp: Pointer to GFS2 superblock
 965  */
 966 static void empty_ail1_list(struct gfs2_sbd *sdp)
 967 {
 968         unsigned long start = jiffies;
 969
 970         for (;;) {
 971                 if (time_after(jiffies, start + (HZ * 600))) {
 972                         fs_err(sdp, "Error: In %s for 10 minutes! t=%d\n",
 973                                __func__, current->journal_info ? 1 : 0);
 974                         dump_ail_list(sdp);
 975                         return;
 976                 }
 977                 gfs2_ail1_start(sdp);
 978                 gfs2_ail1_wait(sdp);
 979                 if (gfs2_ail1_empty(sdp, 0))
 980                         return;
 981         }
 982 }
 983
 984 /**
 985  * trans_drain - drain the buf and databuf queue for a failed transaction
 986  * @tr: the transaction to drain
 987  *
 988  * When this is called, we're taking an error exit for a log write that failed
 989  * but since we bypassed the after_commit functions, we need to remove the
 990  * items from the buf and databuf queue.
 991  */
 992 static void trans_drain(struct gfs2_trans *tr)
 993 {
 994         struct gfs2_bufdata *bd;
 995         struct list_head *head;
 996
 997         if (!tr)
 998                 return;
 999
1000         head = &tr->tr_buf;
1001         while (!list_empty(head)) {
1002                 bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
1003                 list_del_init(&bd->bd_list);
1004                 if (!list_empty(&bd->bd_ail_st_list))
1005                         gfs2_remove_from_ail(bd);
1006                 kmem_cache_free(gfs2_bufdata_cachep, bd);
1007         }
1008         head = &tr->tr_databuf;
1009         while (!list_empty(head)) {
1010                 bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
1011                 list_del_init(&bd->bd_list);
1012                 if (!list_empty(&bd->bd_ail_st_list))
1013                         gfs2_remove_from_ail(bd);
1014                 kmem_cache_free(gfs2_bufdata_cachep, bd);
1015         }
1016 }
1017
1018 /**
1019  * gfs2_log_flush - flush incore transaction(s)
1020  * @sdp: The filesystem
1021  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
1022  * @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags
1023  *
1024  */
1025
1026 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)
1027 {
1028         struct gfs2_trans *tr = NULL;
1029         unsigned int reserved_blocks = 0, used_blocks = 0;
1030         enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
1031         unsigned int first_log_head;
1032         unsigned int reserved_revokes = 0;
1033
1034         down_write(&sdp->sd_log_flush_lock);
1035         trace_gfs2_log_flush(sdp, 1, flags);
1036
1037 repeat:
1038         /*
1039          * Do this check while holding the log_flush_lock to prevent new
1040          * buffers from being added to the ail via gfs2_pin()
1041          */
1042         if (gfs2_withdrawn(sdp) || !test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
1043                 goto out;
1044
1045         /* Log might have been flushed while we waited for the flush lock */
1046         if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags))
1047                 goto out;
1048
1049         first_log_head = sdp->sd_log_head;
1050         sdp->sd_log_flush_head = first_log_head;
1051
1052         tr = sdp->sd_log_tr;
1053         if (tr || sdp->sd_log_num_revoke) {
1054                 if (reserved_blocks)
1055                         gfs2_log_release(sdp, reserved_blocks);
1056                 reserved_blocks = sdp->sd_log_blks_reserved;
1057                 reserved_revokes = sdp->sd_log_num_revoke;
1058                 if (tr) {
1059                         sdp->sd_log_tr = NULL;
1060                         tr->tr_first = first_log_head;
1061                         if (unlikely (state == SFS_FROZEN)) {
1062                                 if (gfs2_assert_withdraw_delayed(sdp,
1063                                        !tr->tr_num_buf_new && !tr->tr_num_databuf_new))
1064                                         goto out_withdraw;
1065                         }
1066                 }
1067         } else if (!reserved_blocks) {
1068                 unsigned int taboo_blocks = GFS2_LOG_FLUSH_MIN_BLOCKS;
1069
1070                 reserved_blocks = GFS2_LOG_FLUSH_MIN_BLOCKS;
1071                 if (current == sdp->sd_logd_process)
1072                         taboo_blocks = 0;
1073
1074                 if (!__gfs2_log_try_reserve(sdp, reserved_blocks, taboo_blocks)) {
1075                         up_write(&sdp->sd_log_flush_lock);
1076                         __gfs2_log_reserve(sdp, reserved_blocks, taboo_blocks);
1077                         down_write(&sdp->sd_log_flush_lock);
1078                         goto repeat;
1079                 }
1080                 BUG_ON(sdp->sd_log_num_revoke);
1081         }
1082
1083         if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN)
1084                 clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
1085
1086         if (unlikely(state == SFS_FROZEN))
1087                 if (gfs2_assert_withdraw_delayed(sdp, !reserved_revokes))
1088                         goto out_withdraw;
1089
1090         gfs2_ordered_write(sdp);
1091         if (gfs2_withdrawn(sdp))
1092                 goto out_withdraw;
1093         lops_before_commit(sdp, tr);
1094         if (gfs2_withdrawn(sdp))
1095                 goto out_withdraw;
1096         gfs2_log_submit_bio(&sdp->sd_jdesc->jd_log_bio, REQ_OP_WRITE);
1097         if (gfs2_withdrawn(sdp))
1098                 goto out_withdraw;
1099
1100         if (sdp->sd_log_head != sdp->sd_log_flush_head) {
1101                 log_write_header(sdp, flags);
1102         } else if (sdp->sd_log_tail != sdp->sd_log_flush_tail && !sdp->sd_log_idle) {
1103                 log_write_header(sdp, flags);
1104         }
1105         if (gfs2_withdrawn(sdp))
1106                 goto out_withdraw;
1107         lops_after_commit(sdp, tr);
1108
1109         gfs2_log_lock(sdp);
1110         sdp->sd_log_blks_reserved = 0;
1111
1112         spin_lock(&sdp->sd_ail_lock);
1113         if (tr && !list_empty(&tr->tr_ail1_list)) {
1114                 list_add(&tr->tr_list, &sdp->sd_ail1_list);
1115                 tr = NULL;
1116         }
1117         spin_unlock(&sdp->sd_ail_lock);
1118         gfs2_log_unlock(sdp);
1119
1120         if (!(flags & GFS2_LOG_HEAD_FLUSH_NORMAL)) {
1121                 if (!sdp->sd_log_idle) {
1122                         empty_ail1_list(sdp);
1123                         if (gfs2_withdrawn(sdp))
1124                                 goto out_withdraw;
1125                         log_write_header(sdp, flags);
1126                 }
1127                 if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
1128                              GFS2_LOG_HEAD_FLUSH_FREEZE))
1129                         gfs2_log_shutdown(sdp);
1130                 if (flags & GFS2_LOG_HEAD_FLUSH_FREEZE)
1131                         atomic_set(&sdp->sd_freeze_state, SFS_FROZEN);
1132         }
1133
1134 out_end:
1135         used_blocks = log_distance(sdp, sdp->sd_log_flush_head, first_log_head);
1136         reserved_revokes += atomic_read(&sdp->sd_log_revokes_available);
1137         atomic_set(&sdp->sd_log_revokes_available, sdp->sd_ldptrs);
1138         gfs2_assert_withdraw(sdp, reserved_revokes % sdp->sd_inptrs == sdp->sd_ldptrs);
1139         if (reserved_revokes > sdp->sd_ldptrs)
1140                 reserved_blocks += (reserved_revokes - sdp->sd_ldptrs) / sdp->sd_inptrs;
1141 out:
1142         if (used_blocks != reserved_blocks) {
1143                 gfs2_assert_withdraw_delayed(sdp, used_blocks < reserved_blocks);
1144                 gfs2_log_release(sdp, reserved_blocks - used_blocks);
1145         }
1146         up_write(&sdp->sd_log_flush_lock);
1147         gfs2_trans_free(sdp, tr);
1148         if (gfs2_withdrawing(sdp))
1149                 gfs2_withdraw(sdp);
1150         trace_gfs2_log_flush(sdp, 0, flags);
1151         return;
1152
1153 out_withdraw:
1154         trans_drain(tr);
1155         /**
1156          * If the tr_list is empty, we're withdrawing during a log
1157          * flush that targets a transaction, but the transaction was
1158          * never queued onto any of the ail lists. Here we add it to
1159          * ail1 just so that ail_drain() will find and free it.
1160          */
1161         spin_lock(&sdp->sd_ail_lock);
1162         if (tr && list_empty(&tr->tr_list))
1163                 list_add(&tr->tr_list, &sdp->sd_ail1_list);
1164         spin_unlock(&sdp->sd_ail_lock);
1165         tr = NULL;
1166         goto out_end;
1167 }
1168
1169 /**
1170  * gfs2_merge_trans - Merge a new transaction into a cached transaction
1171  * @sdp: the filesystem
1172  * @new: New transaction to be merged
1173  */
1174
1175 static void gfs2_merge_trans(struct gfs2_sbd *sdp, struct gfs2_trans *new)
1176 {
1177         struct gfs2_trans *old = sdp->sd_log_tr;
1178
1179         WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags));
1180
1181         old->tr_num_buf_new     += new->tr_num_buf_new;
1182         old->tr_num_databuf_new += new->tr_num_databuf_new;
1183         old->tr_num_buf_rm      += new->tr_num_buf_rm;
1184         old->tr_num_databuf_rm  += new->tr_num_databuf_rm;
1185         old->tr_revokes         += new->tr_revokes;
1186         old->tr_num_revoke      += new->tr_num_revoke;
1187
1188         list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
1189         list_splice_tail_init(&new->tr_buf, &old->tr_buf);
1190
1191         spin_lock(&sdp->sd_ail_lock);
1192         list_splice_tail_init(&new->tr_ail1_list, &old->tr_ail1_list);
1193         list_splice_tail_init(&new->tr_ail2_list, &old->tr_ail2_list);
1194         spin_unlock(&sdp->sd_ail_lock);
1195 }
1196
1197 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1198 {
1199         unsigned int reserved;
1200         unsigned int unused;
1201         unsigned int maxres;
1202
1203         gfs2_log_lock(sdp);
1204
1205         if (sdp->sd_log_tr) {
1206                 gfs2_merge_trans(sdp, tr);
1207         } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
1208                 gfs2_assert_withdraw(sdp, !test_bit(TR_ONSTACK, &tr->tr_flags));
1209                 sdp->sd_log_tr = tr;
1210                 set_bit(TR_ATTACHED, &tr->tr_flags);
1211         }
1212
1213         reserved = calc_reserved(sdp);
1214         maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
1215         gfs2_assert_withdraw(sdp, maxres >= reserved);
1216         unused = maxres - reserved;
1217         if (unused)
1218                 gfs2_log_release(sdp, unused);
1219         sdp->sd_log_blks_reserved = reserved;
1220
1221         gfs2_log_unlock(sdp);
1222 }
1223
1224 /**
1225  * gfs2_log_commit - Commit a transaction to the log
1226  * @sdp: the filesystem
1227  * @tr: the transaction
1228  *
1229  * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
1230  * or the total number of used blocks (pinned blocks plus AIL blocks)
1231  * is greater than thresh2.
1232  *
1233  * At mount time thresh1 is 2/5ths of journal size, thresh2 is 4/5ths of
1234  * journal size.
1235  *
1236  * Returns: errno
1237  */
1238
1239 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1240 {
1241         log_refund(sdp, tr);
1242
1243         if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
1244             ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
1245             atomic_read(&sdp->sd_log_thresh2)))
1246                 wake_up(&sdp->sd_logd_waitq);
1247 }
1248
1249 /**
1250  * gfs2_log_shutdown - write a shutdown header into a journal
1251  * @sdp: the filesystem
1252  *
1253  */
1254
1255 static void gfs2_log_shutdown(struct gfs2_sbd *sdp)
1256 {
1257         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
1258         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
1259         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
1260
1261         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN);
1262         log_pull_tail(sdp);
1263
1264         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
1265         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
1266 }
1267
1268 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
1269 {
1270         return (atomic_read(&sdp->sd_log_pinned) +
1271                 atomic_read(&sdp->sd_log_blks_needed) >=
1272                 atomic_read(&sdp->sd_log_thresh1));
1273 }
1274
1275 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
1276 {
1277         unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
1278
1279         if (test_and_clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags))
1280                 return 1;
1281
1282         return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
1283                 atomic_read(&sdp->sd_log_thresh2);
1284 }
1285
1286 /**
1287  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
1288  * @data: Pointer to GFS2 superblock
1289  *
1290  * Also, periodically check to make sure that we're using the most recent
1291  * journal index.
1292  */
1293
1294 int gfs2_logd(void *data)
1295 {
1296         struct gfs2_sbd *sdp = data;
1297         unsigned long t = 1;
1298         DEFINE_WAIT(wait);
1299
1300         while (!kthread_should_stop()) {
1301
1302                 if (gfs2_withdrawn(sdp)) {
1303                         msleep_interruptible(HZ);
1304                         continue;
1305                 }
1306                 /* Check for errors writing to the journal */
1307                 if (sdp->sd_log_error) {
1308                         gfs2_lm(sdp,
1309                                 "GFS2: fsid=%s: error %d: "
1310                                 "withdrawing the file system to "
1311                                 "prevent further damage.\n",
1312                                 sdp->sd_fsname, sdp->sd_log_error);
1313                         gfs2_withdraw(sdp);
1314                         continue;
1315                 }
1316
1317                 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
1318                         gfs2_ail1_empty(sdp, 0);
1319                         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1320                                                   GFS2_LFC_LOGD_JFLUSH_REQD);
1321                 }
1322
1323                 if (gfs2_ail_flush_reqd(sdp)) {
1324                         gfs2_ail1_start(sdp);
1325                         gfs2_ail1_wait(sdp);
1326                         gfs2_ail1_empty(sdp, 0);
1327                         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1328                                                   GFS2_LFC_LOGD_AIL_FLUSH_REQD);
1329                 }
1330
1331                 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
1332
1333                 try_to_freeze();
1334
1335                 do {
1336                         prepare_to_wait(&sdp->sd_logd_waitq, &wait,
1337                                         TASK_INTERRUPTIBLE);
1338                         if (!gfs2_ail_flush_reqd(sdp) &&
1339                             !gfs2_jrnl_flush_reqd(sdp) &&
1340                             !kthread_should_stop())
1341                                 t = schedule_timeout(t);
1342                 } while(t && !gfs2_ail_flush_reqd(sdp) &&
1343                         !gfs2_jrnl_flush_reqd(sdp) &&
1344                         !kthread_should_stop());
1345                 finish_wait(&sdp->sd_logd_waitq, &wait);
1346         }
1347
1348         return 0;
1349 }
1350