fs/gfs2/log.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/gfs2_ondisk.h>
  16 #include <linux/crc32.h>
  17 #include <linux/lm_interface.h>
  18 #include <linux/delay.h>
  19
  20 #include "gfs2.h"
  21 #include "incore.h"
  22 #include "bmap.h"
  23 #include "glock.h"
  24 #include "log.h"
  25 #include "lops.h"
  26 #include "meta_io.h"
  27 #include "util.h"
  28 #include "dir.h"
  29
  30 #define PULL 1
  31
  32 /**
  33  * gfs2_struct2blk - compute stuff
  34  * @sdp: the filesystem
  35  * @nstruct: the number of structures
  36  * @ssize: the size of the structures
  37  *
  38  * Compute the number of log descriptor blocks needed to hold a certain number
  39  * of structures of a certain size.
  40  *
  41  * Returns: the number of blocks needed (minimum is always 1)
  42  */
  43
  44 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
  45                              unsigned int ssize)
  46 {
  47         unsigned int blks;
  48         unsigned int first, second;
  49
  50         blks = 1;
  51         first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
  52
  53         if (nstruct > first) {
  54                 second = (sdp->sd_sb.sb_bsize -
  55                           sizeof(struct gfs2_meta_header)) / ssize;
  56                 blks += DIV_ROUND_UP(nstruct - first, second);
  57         }
  58
  59         return blks;
  60 }
  61
  62 /**
  63  * gfs2_ail1_start_one - Start I/O on a part of the AIL
  64  * @sdp: the filesystem
  65  * @tr: the part of the AIL
  66  *
  67  */
  68
  69 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
  70 {
  71         struct gfs2_bufdata *bd, *s;
  72         struct buffer_head *bh;
  73         int retry;
  74
  75         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
  76
  77         do {
  78                 retry = 0;
  79
  80                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
  81                                                  bd_ail_st_list) {
  82                         bh = bd->bd_bh;
  83
  84                         gfs2_assert(sdp, bd->bd_ail == ai);
  85
  86                         if (!buffer_busy(bh)) {
  87                                 if (!buffer_uptodate(bh)) {
  88                                         gfs2_log_unlock(sdp);
  89                                         gfs2_io_error_bh(sdp, bh);
  90                                         gfs2_log_lock(sdp);
  91                                 }
  92                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
  93                                 continue;
  94                         }
  95
  96                         if (!buffer_dirty(bh))
  97                                 continue;
  98
  99                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 100
 101                         gfs2_log_unlock(sdp);
 102                         wait_on_buffer(bh);
 103                         ll_rw_block(WRITE, 1, &bh);
 104                         gfs2_log_lock(sdp);
 105
 106                         retry = 1;
 107                         break;
 108                 }
 109         } while (retry);
 110 }
 111
 112 /**
 113  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 114  * @sdp: the filesystem
 115  * @ai: the AIL entry
 116  *
 117  */
 118
 119 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 120 {
 121         struct gfs2_bufdata *bd, *s;
 122         struct buffer_head *bh;
 123
 124         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 125                                          bd_ail_st_list) {
 126                 bh = bd->bd_bh;
 127
 128                 gfs2_assert(sdp, bd->bd_ail == ai);
 129
 130                 if (buffer_busy(bh)) {
 131                         if (flags & DIO_ALL)
 132                                 continue;
 133                         else
 134                                 break;
 135                 }
 136
 137                 if (!buffer_uptodate(bh))
 138                         gfs2_io_error_bh(sdp, bh);
 139
 140                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 141         }
 142
 143         return list_empty(&ai->ai_ail1_list);
 144 }
 145
 146 static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
 147 {
 148         struct list_head *head;
 149         u64 sync_gen;
 150         struct list_head *first;
 151         struct gfs2_ail *first_ai, *ai, *tmp;
 152         int done = 0;
 153
 154         gfs2_log_lock(sdp);
 155         head = &sdp->sd_ail1_list;
 156         if (list_empty(head)) {
 157                 gfs2_log_unlock(sdp);
 158                 return;
 159         }
 160         sync_gen = sdp->sd_ail_sync_gen++;
 161
 162         first = head->prev;
 163         first_ai = list_entry(first, struct gfs2_ail, ai_list);
 164         first_ai->ai_sync_gen = sync_gen;
 165         gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */
 166
 167         if (flags & DIO_ALL)
 168                 first = NULL;
 169
 170         while(!done) {
 171                 if (first && (head->prev != first ||
 172                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
 173                         break;
 174
 175                 done = 1;
 176                 list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) {
 177                         if (ai->ai_sync_gen >= sync_gen)
 178                                 continue;
 179                         ai->ai_sync_gen = sync_gen;
 180                         gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
 181                         done = 0;
 182                         break;
 183                 }
 184         }
 185
 186         gfs2_log_unlock(sdp);
 187 }
 188
 189 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
 190 {
 191         struct gfs2_ail *ai, *s;
 192         int ret;
 193
 194         gfs2_log_lock(sdp);
 195
 196         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
 197                 if (gfs2_ail1_empty_one(sdp, ai, flags))
 198                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
 199                 else if (!(flags & DIO_ALL))
 200                         break;
 201         }
 202
 203         ret = list_empty(&sdp->sd_ail1_list);
 204
 205         gfs2_log_unlock(sdp);
 206
 207         return ret;
 208 }
 209
 210
 211 /**
 212  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 213  * @sdp: the filesystem
 214  * @ai: the AIL entry
 215  *
 216  */
 217
 218 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 219 {
 220         struct list_head *head = &ai->ai_ail2_list;
 221         struct gfs2_bufdata *bd;
 222         struct gfs2_inode *bh_ip;
 223
 224         while (!list_empty(head)) {
 225                 bd = list_entry(head->prev, struct gfs2_bufdata,
 226                                 bd_ail_st_list);
 227                 gfs2_assert(sdp, bd->bd_ail == ai);
 228                 bd->bd_ail = NULL;
 229                 list_del(&bd->bd_ail_st_list);
 230                 list_del(&bd->bd_ail_gl_list);
 231                 atomic_dec(&bd->bd_gl->gl_ail_count);
 232                 if (bd->bd_bh->b_page->mapping) {
 233                         bh_ip = GFS2_I(bd->bd_bh->b_page->mapping->host);
 234                         gfs2_meta_cache_flush(bh_ip);
 235                 }
 236                 brelse(bd->bd_bh);
 237         }
 238 }
 239
 240 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 241 {
 242         struct gfs2_ail *ai, *safe;
 243         unsigned int old_tail = sdp->sd_log_tail;
 244         int wrap = (new_tail < old_tail);
 245         int a, b, rm;
 246
 247         gfs2_log_lock(sdp);
 248
 249         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 250                 a = (old_tail <= ai->ai_first);
 251                 b = (ai->ai_first < new_tail);
 252                 rm = (wrap) ? (a || b) : (a && b);
 253                 if (!rm)
 254                         continue;
 255
 256                 gfs2_ail2_empty_one(sdp, ai);
 257                 list_del(&ai->ai_list);
 258                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 259                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 260                 kfree(ai);
 261         }
 262
 263         gfs2_log_unlock(sdp);
 264 }
 265
 266 /**
 267  * gfs2_log_reserve - Make a log reservation
 268  * @sdp: The GFS2 superblock
 269  * @blks: The number of blocks to reserve
 270  *
 271  * Note that we never give out the last few blocks of the journal. Thats
 272  * due to the fact that there is a small number of header blocks
 273  * associated with each log flush. The exact number can't be known until
 274  * flush time, so we ensure that we have just enough free blocks at all
 275  * times to avoid running out during a log flush.
 276  *
 277  * Returns: errno
 278  */
 279
 280 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 281 {
 282         unsigned int try = 0;
 283         unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
 284
 285         if (gfs2_assert_warn(sdp, blks) ||
 286             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 287                 return -EINVAL;
 288
 289         mutex_lock(&sdp->sd_log_reserve_mutex);
 290         gfs2_log_lock(sdp);
 291         while(sdp->sd_log_blks_free <= (blks + reserved_blks)) {
 292                 gfs2_log_unlock(sdp);
 293                 gfs2_ail1_empty(sdp, 0);
 294                 gfs2_log_flush(sdp, NULL);
 295
 296                 if (try++)
 297                         gfs2_ail1_start(sdp, 0);
 298                 gfs2_log_lock(sdp);
 299         }
 300         sdp->sd_log_blks_free -= blks;
 301         gfs2_log_unlock(sdp);
 302         mutex_unlock(&sdp->sd_log_reserve_mutex);
 303
 304         down_read(&sdp->sd_log_flush_lock);
 305
 306         return 0;
 307 }
 308
 309 /**
 310  * gfs2_log_release - Release a given number of log blocks
 311  * @sdp: The GFS2 superblock
 312  * @blks: The number of blocks
 313  *
 314  */
 315
 316 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 317 {
 318
 319         gfs2_log_lock(sdp);
 320         sdp->sd_log_blks_free += blks;
 321         gfs2_assert_withdraw(sdp,
 322                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 323         gfs2_log_unlock(sdp);
 324         up_read(&sdp->sd_log_flush_lock);
 325 }
 326
 327 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 328 {
 329         struct inode *inode = sdp->sd_jdesc->jd_inode;
 330         int error;
 331         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 332
 333         bh_map.b_size = 1 << inode->i_blkbits;
 334         error = gfs2_block_map(inode, lbn, 0, &bh_map);
 335         if (error || !bh_map.b_blocknr)
 336                 printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error,
 337                        (unsigned long long)bh_map.b_blocknr, lbn);
 338         gfs2_assert_withdraw(sdp, !error && bh_map.b_blocknr);
 339
 340         return bh_map.b_blocknr;
 341 }
 342
 343 /**
 344  * log_distance - Compute distance between two journal blocks
 345  * @sdp: The GFS2 superblock
 346  * @newer: The most recent journal block of the pair
 347  * @older: The older journal block of the pair
 348  *
 349  *   Compute the distance (in the journal direction) between two
 350  *   blocks in the journal
 351  *
 352  * Returns: the distance in blocks
 353  */
 354
 355 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 356                                         unsigned int older)
 357 {
 358         int dist;
 359
 360         dist = newer - older;
 361         if (dist < 0)
 362                 dist += sdp->sd_jdesc->jd_blocks;
 363
 364         return dist;
 365 }
 366
 367 /**
 368  * calc_reserved - Calculate the number of blocks to reserve when
 369  *                 refunding a transaction's unused buffers.
 370  * @sdp: The GFS2 superblock
 371  *
 372  * This is complex.  We need to reserve room for all our currently used
 373  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
 374  * all our journaled data buffers for journaled files (e.g. files in the
 375  * meta_fs like rindex, or files for which chattr +j was done.)
 376  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
 377  * will count it as free space (sd_log_blks_free) and corruption will follow.
 378  *
 379  * We can have metadata bufs and jdata bufs in the same journal.  So each
 380  * type gets its own log header, for which we need to reserve a block.
 381  * In fact, each type has the potential for needing more than one header
 382  * in cases where we have more buffers than will fit on a journal page.
 383  * Metadata journal entries take up half the space of journaled buffer entries.
 384  * Thus, metadata entries have buf_limit (502) and journaled buffers have
 385  * databuf_limit (251) before they cause a wrap around.
 386  *
 387  * Also, we need to reserve blocks for revoke journal entries and one for an
 388  * overall header for the lot.
 389  *
 390  * Returns: the number of blocks reserved
 391  */
 392 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 393 {
 394         unsigned int reserved = 0;
 395         unsigned int mbuf_limit, metabufhdrs_needed;
 396         unsigned int dbuf_limit, databufhdrs_needed;
 397         unsigned int revokes = 0;
 398
 399         mbuf_limit = buf_limit(sdp);
 400         metabufhdrs_needed = (sdp->sd_log_commited_buf +
 401                               (mbuf_limit - 1)) / mbuf_limit;
 402         dbuf_limit = databuf_limit(sdp);
 403         databufhdrs_needed = (sdp->sd_log_commited_databuf +
 404                               (dbuf_limit - 1)) / dbuf_limit;
 405
 406         if (sdp->sd_log_commited_revoke)
 407                 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 408                                           sizeof(u64));
 409
 410         reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
 411                 sdp->sd_log_commited_databuf + databufhdrs_needed +
 412                 revokes;
 413         /* One for the overall header */
 414         if (reserved)
 415                 reserved++;
 416         return reserved;
 417 }
 418
 419 static unsigned int current_tail(struct gfs2_sbd *sdp)
 420 {
 421         struct gfs2_ail *ai;
 422         unsigned int tail;
 423
 424         gfs2_log_lock(sdp);
 425
 426         if (list_empty(&sdp->sd_ail1_list)) {
 427                 tail = sdp->sd_log_head;
 428         } else {
 429                 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
 430                 tail = ai->ai_first;
 431         }
 432
 433         gfs2_log_unlock(sdp);
 434
 435         return tail;
 436 }
 437
 438 static inline void log_incr_head(struct gfs2_sbd *sdp)
 439 {
 440         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 441                 gfs2_assert_withdraw(sdp, sdp->sd_log_flush_head == sdp->sd_log_head);
 442
 443         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 444                 sdp->sd_log_flush_head = 0;
 445                 sdp->sd_log_flush_wrapped = 1;
 446         }
 447 }
 448
 449 /**
 450  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 451  * @sdp: The GFS2 superblock
 452  *
 453  * Returns: the buffer_head
 454  */
 455
 456 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 457 {
 458         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 459         struct gfs2_log_buf *lb;
 460         struct buffer_head *bh;
 461
 462         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 463         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 464
 465         bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
 466         lock_buffer(bh);
 467         memset(bh->b_data, 0, bh->b_size);
 468         set_buffer_uptodate(bh);
 469         clear_buffer_dirty(bh);
 470         unlock_buffer(bh);
 471
 472         log_incr_head(sdp);
 473
 474         return bh;
 475 }
 476
 477 /**
 478  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 479  * @sdp: the filesystem
 480  * @data: the data the buffer_head should point to
 481  *
 482  * Returns: the log buffer descriptor
 483  */
 484
 485 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 486                                       struct buffer_head *real)
 487 {
 488         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 489         struct gfs2_log_buf *lb;
 490         struct buffer_head *bh;
 491
 492         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 493         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 494         lb->lb_real = real;
 495
 496         bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 497         atomic_set(&bh->b_count, 1);
 498         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
 499         set_bh_page(bh, real->b_page, bh_offset(real));
 500         bh->b_blocknr = blkno;
 501         bh->b_size = sdp->sd_sb.sb_bsize;
 502         bh->b_bdev = sdp->sd_vfs->s_bdev;
 503
 504         log_incr_head(sdp);
 505
 506         return bh;
 507 }
 508
 509 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 510 {
 511         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 512
 513         ail2_empty(sdp, new_tail);
 514
 515         gfs2_log_lock(sdp);
 516         sdp->sd_log_blks_free += dist;
 517         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 518         gfs2_log_unlock(sdp);
 519
 520         sdp->sd_log_tail = new_tail;
 521 }
 522
 523 /**
 524  * log_write_header - Get and initialize a journal header buffer
 525  * @sdp: The GFS2 superblock
 526  *
 527  * Returns: the initialized log buffer descriptor
 528  */
 529
 530 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 531 {
 532         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 533         struct buffer_head *bh;
 534         struct gfs2_log_header *lh;
 535         unsigned int tail;
 536         u32 hash;
 537
 538         bh = sb_getblk(sdp->sd_vfs, blkno);
 539         lock_buffer(bh);
 540         memset(bh->b_data, 0, bh->b_size);
 541         set_buffer_uptodate(bh);
 542         clear_buffer_dirty(bh);
 543         unlock_buffer(bh);
 544
 545         gfs2_ail1_empty(sdp, 0);
 546         tail = current_tail(sdp);
 547
 548         lh = (struct gfs2_log_header *)bh->b_data;
 549         memset(lh, 0, sizeof(struct gfs2_log_header));
 550         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 551         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 552         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 553         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
 554         lh->lh_flags = cpu_to_be32(flags);
 555         lh->lh_tail = cpu_to_be32(tail);
 556         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
 557         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 558         lh->lh_hash = cpu_to_be32(hash);
 559
 560         set_buffer_dirty(bh);
 561         if (sync_dirty_buffer(bh))
 562                 gfs2_io_error_bh(sdp, bh);
 563         brelse(bh);
 564
 565         if (sdp->sd_log_tail != tail)
 566                 log_pull_tail(sdp, tail);
 567         else
 568                 gfs2_assert_withdraw(sdp, !pull);
 569
 570         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 571         log_incr_head(sdp);
 572 }
 573
 574 static void log_flush_commit(struct gfs2_sbd *sdp)
 575 {
 576         struct list_head *head = &sdp->sd_log_flush_list;
 577         struct gfs2_log_buf *lb;
 578         struct buffer_head *bh;
 579         int flushcount = 0;
 580
 581         while (!list_empty(head)) {
 582                 lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
 583                 list_del(&lb->lb_list);
 584                 bh = lb->lb_bh;
 585
 586                 wait_on_buffer(bh);
 587                 if (!buffer_uptodate(bh))
 588                         gfs2_io_error_bh(sdp, bh);
 589                 if (lb->lb_real) {
 590                         while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
 591                                 schedule();
 592                         free_buffer_head(bh);
 593                 } else
 594                         brelse(bh);
 595                 kfree(lb);
 596                 flushcount++;
 597         }
 598
 599         /* If nothing was journaled, the header is unplanned and unwanted. */
 600         if (flushcount) {
 601                 log_write_header(sdp, 0, 0);
 602         } else {
 603                 unsigned int tail;
 604                 tail = current_tail(sdp);
 605
 606                 gfs2_ail1_empty(sdp, 0);
 607                 if (sdp->sd_log_tail != tail)
 608                         log_pull_tail(sdp, tail);
 609         }
 610 }
 611
 612 /**
 613  * gfs2_log_flush - flush incore transaction(s)
 614  * @sdp: the filesystem
 615  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 616  *
 617  */
 618
 619 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 620 {
 621         struct gfs2_ail *ai;
 622
 623         down_write(&sdp->sd_log_flush_lock);
 624
 625         if (gl) {
 626                 gfs2_log_lock(sdp);
 627                 if (list_empty(&gl->gl_le.le_list)) {
 628                         gfs2_log_unlock(sdp);
 629                         up_write(&sdp->sd_log_flush_lock);
 630                         return;
 631                 }
 632                 gfs2_log_unlock(sdp);
 633         }
 634
 635         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 636         INIT_LIST_HEAD(&ai->ai_ail1_list);
 637         INIT_LIST_HEAD(&ai->ai_ail2_list);
 638
 639         gfs2_assert_withdraw(sdp,
 640                              sdp->sd_log_num_buf + sdp->sd_log_num_jdata ==
 641                              sdp->sd_log_commited_buf +
 642                              sdp->sd_log_commited_databuf);
 643         gfs2_assert_withdraw(sdp,
 644                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 645
 646         sdp->sd_log_flush_head = sdp->sd_log_head;
 647         sdp->sd_log_flush_wrapped = 0;
 648         ai->ai_first = sdp->sd_log_flush_head;
 649
 650         lops_before_commit(sdp);
 651         if (!list_empty(&sdp->sd_log_flush_list))
 652                 log_flush_commit(sdp);
 653         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 654                 gfs2_log_lock(sdp);
 655                 sdp->sd_log_blks_free--; /* Adjust for unreserved buffer */
 656                 gfs2_log_unlock(sdp);
 657                 log_write_header(sdp, 0, PULL);
 658         }
 659         lops_after_commit(sdp, ai);
 660
 661         gfs2_log_lock(sdp);
 662         sdp->sd_log_head = sdp->sd_log_flush_head;
 663         sdp->sd_log_blks_reserved = 0;
 664         sdp->sd_log_commited_buf = 0;
 665         sdp->sd_log_commited_databuf = 0;
 666         sdp->sd_log_commited_revoke = 0;
 667
 668         if (!list_empty(&ai->ai_ail1_list)) {
 669                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 670                 ai = NULL;
 671         }
 672         gfs2_log_unlock(sdp);
 673
 674         sdp->sd_vfs->s_dirt = 0;
 675         up_write(&sdp->sd_log_flush_lock);
 676
 677         kfree(ai);
 678 }
 679
 680 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 681 {
 682         unsigned int reserved;
 683         unsigned int old;
 684
 685         gfs2_log_lock(sdp);
 686
 687         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 688         sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
 689                 tr->tr_num_databuf_rm;
 690         gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
 691                              (((int)sdp->sd_log_commited_databuf) >= 0));
 692         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 693         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 694         reserved = calc_reserved(sdp);
 695         old = sdp->sd_log_blks_free;
 696         sdp->sd_log_blks_free += tr->tr_reserved -
 697                                  (reserved - sdp->sd_log_blks_reserved);
 698
 699         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 700         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <=
 701                              sdp->sd_jdesc->jd_blocks);
 702
 703         sdp->sd_log_blks_reserved = reserved;
 704
 705         gfs2_log_unlock(sdp);
 706 }
 707
 708 /**
 709  * gfs2_log_commit - Commit a transaction to the log
 710  * @sdp: the filesystem
 711  * @tr: the transaction
 712  *
 713  * Returns: errno
 714  */
 715
 716 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 717 {
 718         log_refund(sdp, tr);
 719         lops_incore_commit(sdp, tr);
 720
 721         sdp->sd_vfs->s_dirt = 1;
 722         up_read(&sdp->sd_log_flush_lock);
 723
 724         gfs2_log_lock(sdp);
 725         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks))
 726                 wake_up_process(sdp->sd_logd_process);
 727         gfs2_log_unlock(sdp);
 728 }
 729
 730 /**
 731  * gfs2_log_shutdown - write a shutdown header into a journal
 732  * @sdp: the filesystem
 733  *
 734  */
 735
 736 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 737 {
 738         down_write(&sdp->sd_log_flush_lock);
 739
 740         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 741         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 742         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 743         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
 744         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 745         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 746         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 747         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 748
 749         sdp->sd_log_flush_head = sdp->sd_log_head;
 750         sdp->sd_log_flush_wrapped = 0;
 751
 752         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
 753                          (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
 754
 755         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
 756         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 757         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 758
 759         sdp->sd_log_head = sdp->sd_log_flush_head;
 760         sdp->sd_log_tail = sdp->sd_log_head;
 761
 762         up_write(&sdp->sd_log_flush_lock);
 763 }
 764
 765
 766 /**
 767  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 768  * @sdp: the filesystem
 769  *
 770  */
 771
 772 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 773 {
 774         gfs2_log_flush(sdp, NULL);
 775         for (;;) {
 776                 gfs2_ail1_start(sdp, DIO_ALL);
 777                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 778                         break;
 779                 msleep(10);
 780         }
 781 }
 782