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 (!bh){
  87                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
  88                                 continue;
  89                         }
  90
  91                         if (!buffer_busy(bh)) {
  92                                 if (!buffer_uptodate(bh)) {
  93                                         gfs2_log_unlock(sdp);
  94                                         gfs2_io_error_bh(sdp, bh);
  95                                         gfs2_log_lock(sdp);
  96                                 }
  97                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
  98                                 continue;
  99                         }
 100
 101                         if (!buffer_dirty(bh))
 102                                 continue;
 103
 104                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 105
 106                         gfs2_log_unlock(sdp);
 107                         wait_on_buffer(bh);
 108                         ll_rw_block(WRITE, 1, &bh);
 109                         gfs2_log_lock(sdp);
 110
 111                         retry = 1;
 112                         break;
 113                 }
 114         } while (retry);
 115 }
 116
 117 /**
 118  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 119  * @sdp: the filesystem
 120  * @ai: the AIL entry
 121  *
 122  */
 123
 124 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 125 {
 126         struct gfs2_bufdata *bd, *s;
 127         struct buffer_head *bh;
 128
 129         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 130                                          bd_ail_st_list) {
 131                 bh = bd->bd_bh;
 132
 133                 if (!bh){
 134                         list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 135                         continue;
 136                 }
 137
 138                 gfs2_assert(sdp, bd->bd_ail == ai);
 139
 140                 if (buffer_busy(bh)) {
 141                         if (flags & DIO_ALL)
 142                                 continue;
 143                         else
 144                                 break;
 145                 }
 146
 147                 if (!buffer_uptodate(bh))
 148                         gfs2_io_error_bh(sdp, bh);
 149
 150                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 151         }
 152
 153         return list_empty(&ai->ai_ail1_list);
 154 }
 155
 156 static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
 157 {
 158         struct list_head *head = &sdp->sd_ail1_list;
 159         u64 sync_gen;
 160         struct list_head *first;
 161         struct gfs2_ail *first_ai, *ai, *tmp;
 162         int done = 0;
 163
 164         gfs2_log_lock(sdp);
 165         if (list_empty(head)) {
 166                 gfs2_log_unlock(sdp);
 167                 return;
 168         }
 169         sync_gen = sdp->sd_ail_sync_gen++;
 170
 171         first = head->prev;
 172         first_ai = list_entry(first, struct gfs2_ail, ai_list);
 173         first_ai->ai_sync_gen = sync_gen;
 174         gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */
 175
 176         if (flags & DIO_ALL)
 177                 first = NULL;
 178
 179         while(!done) {
 180                 if (first && (head->prev != first ||
 181                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
 182                         break;
 183
 184                 done = 1;
 185                 list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) {
 186                         if (ai->ai_sync_gen >= sync_gen)
 187                                 continue;
 188                         ai->ai_sync_gen = sync_gen;
 189                         gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
 190                         done = 0;
 191                         break;
 192                 }
 193         }
 194
 195         gfs2_log_unlock(sdp);
 196 }
 197
 198 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
 199 {
 200         struct gfs2_ail *ai, *s;
 201         int ret;
 202
 203         gfs2_log_lock(sdp);
 204
 205         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
 206                 if (gfs2_ail1_empty_one(sdp, ai, flags))
 207                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
 208                 else if (!(flags & DIO_ALL))
 209                         break;
 210         }
 211
 212         ret = list_empty(&sdp->sd_ail1_list);
 213
 214         gfs2_log_unlock(sdp);
 215
 216         return ret;
 217 }
 218
 219
 220 /**
 221  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 222  * @sdp: the filesystem
 223  * @ai: the AIL entry
 224  *
 225  */
 226
 227 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 228 {
 229         struct list_head *head = &ai->ai_ail2_list;
 230         struct gfs2_bufdata *bd;
 231
 232         while (!list_empty(head)) {
 233                 bd = list_entry(head->prev, struct gfs2_bufdata,
 234                                 bd_ail_st_list);
 235                 gfs2_assert(sdp, bd->bd_ail == ai);
 236                 bd->bd_ail = NULL;
 237                 list_del(&bd->bd_ail_st_list);
 238                 list_del(&bd->bd_ail_gl_list);
 239                 atomic_dec(&bd->bd_gl->gl_ail_count);
 240                 if (bd->bd_bh)
 241                         brelse(bd->bd_bh);
 242                 else
 243                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 244         }
 245 }
 246
 247 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 248 {
 249         struct gfs2_ail *ai, *safe;
 250         unsigned int old_tail = sdp->sd_log_tail;
 251         int wrap = (new_tail < old_tail);
 252         int a, b, rm;
 253
 254         gfs2_log_lock(sdp);
 255
 256         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 257                 a = (old_tail <= ai->ai_first);
 258                 b = (ai->ai_first < new_tail);
 259                 rm = (wrap) ? (a || b) : (a && b);
 260                 if (!rm)
 261                         continue;
 262
 263                 gfs2_ail2_empty_one(sdp, ai);
 264                 list_del(&ai->ai_list);
 265                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 266                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 267                 kfree(ai);
 268         }
 269
 270         gfs2_log_unlock(sdp);
 271 }
 272
 273 /**
 274  * gfs2_log_reserve - Make a log reservation
 275  * @sdp: The GFS2 superblock
 276  * @blks: The number of blocks to reserve
 277  *
 278  * Note that we never give out the last few blocks of the journal. Thats
 279  * due to the fact that there is a small number of header blocks
 280  * associated with each log flush. The exact number can't be known until
 281  * flush time, so we ensure that we have just enough free blocks at all
 282  * times to avoid running out during a log flush.
 283  *
 284  * Returns: errno
 285  */
 286
 287 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 288 {
 289         unsigned int try = 0;
 290         unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
 291
 292         if (gfs2_assert_warn(sdp, blks) ||
 293             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 294                 return -EINVAL;
 295
 296         mutex_lock(&sdp->sd_log_reserve_mutex);
 297         gfs2_log_lock(sdp);
 298         while(sdp->sd_log_blks_free <= (blks + reserved_blks)) {
 299                 gfs2_log_unlock(sdp);
 300                 gfs2_ail1_empty(sdp, 0);
 301                 gfs2_log_flush(sdp, NULL);
 302
 303                 if (try++)
 304                         gfs2_ail1_start(sdp, 0);
 305                 gfs2_log_lock(sdp);
 306         }
 307         sdp->sd_log_blks_free -= blks;
 308         gfs2_log_unlock(sdp);
 309         mutex_unlock(&sdp->sd_log_reserve_mutex);
 310
 311         down_read(&sdp->sd_log_flush_lock);
 312
 313         return 0;
 314 }
 315
 316 /**
 317  * gfs2_log_release - Release a given number of log blocks
 318  * @sdp: The GFS2 superblock
 319  * @blks: The number of blocks
 320  *
 321  */
 322
 323 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 324 {
 325
 326         gfs2_log_lock(sdp);
 327         sdp->sd_log_blks_free += blks;
 328         gfs2_assert_withdraw(sdp,
 329                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 330         gfs2_log_unlock(sdp);
 331         up_read(&sdp->sd_log_flush_lock);
 332 }
 333
 334 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 335 {
 336         struct inode *inode = sdp->sd_jdesc->jd_inode;
 337         int error;
 338         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 339
 340         bh_map.b_size = 1 << inode->i_blkbits;
 341         error = gfs2_block_map(inode, lbn, 0, &bh_map);
 342         if (error || !bh_map.b_blocknr)
 343                 printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error,
 344                        (unsigned long long)bh_map.b_blocknr, lbn);
 345         gfs2_assert_withdraw(sdp, !error && bh_map.b_blocknr);
 346
 347         return bh_map.b_blocknr;
 348 }
 349
 350 /**
 351  * log_distance - Compute distance between two journal blocks
 352  * @sdp: The GFS2 superblock
 353  * @newer: The most recent journal block of the pair
 354  * @older: The older journal block of the pair
 355  *
 356  *   Compute the distance (in the journal direction) between two
 357  *   blocks in the journal
 358  *
 359  * Returns: the distance in blocks
 360  */
 361
 362 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 363                                         unsigned int older)
 364 {
 365         int dist;
 366
 367         dist = newer - older;
 368         if (dist < 0)
 369                 dist += sdp->sd_jdesc->jd_blocks;
 370
 371         return dist;
 372 }
 373
 374 /**
 375  * calc_reserved - Calculate the number of blocks to reserve when
 376  *                 refunding a transaction's unused buffers.
 377  * @sdp: The GFS2 superblock
 378  *
 379  * This is complex.  We need to reserve room for all our currently used
 380  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
 381  * all our journaled data buffers for journaled files (e.g. files in the
 382  * meta_fs like rindex, or files for which chattr +j was done.)
 383  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
 384  * will count it as free space (sd_log_blks_free) and corruption will follow.
 385  *
 386  * We can have metadata bufs and jdata bufs in the same journal.  So each
 387  * type gets its own log header, for which we need to reserve a block.
 388  * In fact, each type has the potential for needing more than one header
 389  * in cases where we have more buffers than will fit on a journal page.
 390  * Metadata journal entries take up half the space of journaled buffer entries.
 391  * Thus, metadata entries have buf_limit (502) and journaled buffers have
 392  * databuf_limit (251) before they cause a wrap around.
 393  *
 394  * Also, we need to reserve blocks for revoke journal entries and one for an
 395  * overall header for the lot.
 396  *
 397  * Returns: the number of blocks reserved
 398  */
 399 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 400 {
 401         unsigned int reserved = 0;
 402         unsigned int mbuf_limit, metabufhdrs_needed;
 403         unsigned int dbuf_limit, databufhdrs_needed;
 404         unsigned int revokes = 0;
 405
 406         mbuf_limit = buf_limit(sdp);
 407         metabufhdrs_needed = (sdp->sd_log_commited_buf +
 408                               (mbuf_limit - 1)) / mbuf_limit;
 409         dbuf_limit = databuf_limit(sdp);
 410         databufhdrs_needed = (sdp->sd_log_commited_databuf +
 411                               (dbuf_limit - 1)) / dbuf_limit;
 412
 413         if (sdp->sd_log_commited_revoke)
 414                 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 415                                           sizeof(u64));
 416
 417         reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
 418                 sdp->sd_log_commited_databuf + databufhdrs_needed +
 419                 revokes;
 420         /* One for the overall header */
 421         if (reserved)
 422                 reserved++;
 423         return reserved;
 424 }
 425
 426 static unsigned int current_tail(struct gfs2_sbd *sdp)
 427 {
 428         struct gfs2_ail *ai;
 429         unsigned int tail;
 430
 431         gfs2_log_lock(sdp);
 432
 433         if (list_empty(&sdp->sd_ail1_list)) {
 434                 tail = sdp->sd_log_head;
 435         } else {
 436                 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
 437                 tail = ai->ai_first;
 438         }
 439
 440         gfs2_log_unlock(sdp);
 441
 442         return tail;
 443 }
 444
 445 static inline void log_incr_head(struct gfs2_sbd *sdp)
 446 {
 447         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 448                 gfs2_assert_withdraw(sdp, sdp->sd_log_flush_head == sdp->sd_log_head);
 449
 450         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 451                 sdp->sd_log_flush_head = 0;
 452                 sdp->sd_log_flush_wrapped = 1;
 453         }
 454 }
 455
 456 /**
 457  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 458  * @sdp: The GFS2 superblock
 459  *
 460  * Returns: the buffer_head
 461  */
 462
 463 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 464 {
 465         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 466         struct gfs2_log_buf *lb;
 467         struct buffer_head *bh;
 468
 469         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 470         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 471
 472         bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
 473         lock_buffer(bh);
 474         memset(bh->b_data, 0, bh->b_size);
 475         set_buffer_uptodate(bh);
 476         clear_buffer_dirty(bh);
 477         unlock_buffer(bh);
 478
 479         log_incr_head(sdp);
 480
 481         return bh;
 482 }
 483
 484 /**
 485  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 486  * @sdp: the filesystem
 487  * @data: the data the buffer_head should point to
 488  *
 489  * Returns: the log buffer descriptor
 490  */
 491
 492 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 493                                       struct buffer_head *real)
 494 {
 495         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 496         struct gfs2_log_buf *lb;
 497         struct buffer_head *bh;
 498
 499         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 500         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 501         lb->lb_real = real;
 502
 503         bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 504         atomic_set(&bh->b_count, 1);
 505         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
 506         set_bh_page(bh, real->b_page, bh_offset(real));
 507         bh->b_blocknr = blkno;
 508         bh->b_size = sdp->sd_sb.sb_bsize;
 509         bh->b_bdev = sdp->sd_vfs->s_bdev;
 510
 511         log_incr_head(sdp);
 512
 513         return bh;
 514 }
 515
 516 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 517 {
 518         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 519
 520         ail2_empty(sdp, new_tail);
 521
 522         gfs2_log_lock(sdp);
 523         sdp->sd_log_blks_free += dist;
 524         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 525         gfs2_log_unlock(sdp);
 526
 527         sdp->sd_log_tail = new_tail;
 528 }
 529
 530 /**
 531  * log_write_header - Get and initialize a journal header buffer
 532  * @sdp: The GFS2 superblock
 533  *
 534  * Returns: the initialized log buffer descriptor
 535  */
 536
 537 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 538 {
 539         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 540         struct buffer_head *bh;
 541         struct gfs2_log_header *lh;
 542         unsigned int tail;
 543         u32 hash;
 544
 545         bh = sb_getblk(sdp->sd_vfs, blkno);
 546         lock_buffer(bh);
 547         memset(bh->b_data, 0, bh->b_size);
 548         set_buffer_uptodate(bh);
 549         clear_buffer_dirty(bh);
 550         unlock_buffer(bh);
 551
 552         gfs2_ail1_empty(sdp, 0);
 553         tail = current_tail(sdp);
 554
 555         lh = (struct gfs2_log_header *)bh->b_data;
 556         memset(lh, 0, sizeof(struct gfs2_log_header));
 557         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 558         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 559         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 560         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
 561         lh->lh_flags = cpu_to_be32(flags);
 562         lh->lh_tail = cpu_to_be32(tail);
 563         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
 564         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 565         lh->lh_hash = cpu_to_be32(hash);
 566
 567         set_buffer_dirty(bh);
 568         if (sync_dirty_buffer(bh))
 569                 gfs2_io_error_bh(sdp, bh);
 570         brelse(bh);
 571
 572         if (sdp->sd_log_tail != tail)
 573                 log_pull_tail(sdp, tail);
 574         else
 575                 gfs2_assert_withdraw(sdp, !pull);
 576
 577         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 578         log_incr_head(sdp);
 579 }
 580
 581 static void log_flush_commit(struct gfs2_sbd *sdp)
 582 {
 583         struct list_head *head = &sdp->sd_log_flush_list;
 584         struct gfs2_log_buf *lb;
 585         struct buffer_head *bh;
 586
 587         while (!list_empty(head)) {
 588                 lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
 589                 list_del(&lb->lb_list);
 590                 bh = lb->lb_bh;
 591
 592                 wait_on_buffer(bh);
 593                 if (!buffer_uptodate(bh))
 594                         gfs2_io_error_bh(sdp, bh);
 595                 if (lb->lb_real) {
 596                         while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
 597                                 schedule();
 598                         free_buffer_head(bh);
 599                 } else
 600                         brelse(bh);
 601                 kfree(lb);
 602         }
 603
 604         log_write_header(sdp, 0, 0);
 605 }
 606
 607 /**
 608  * gfs2_log_flush - flush incore transaction(s)
 609  * @sdp: the filesystem
 610  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 611  *
 612  */
 613
 614 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 615 {
 616         struct gfs2_ail *ai;
 617
 618         down_write(&sdp->sd_log_flush_lock);
 619
 620         if (gl) {
 621                 gfs2_log_lock(sdp);
 622                 if (list_empty(&gl->gl_le.le_list)) {
 623                         gfs2_log_unlock(sdp);
 624                         up_write(&sdp->sd_log_flush_lock);
 625                         return;
 626                 }
 627                 gfs2_log_unlock(sdp);
 628         }
 629
 630         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 631         INIT_LIST_HEAD(&ai->ai_ail1_list);
 632         INIT_LIST_HEAD(&ai->ai_ail2_list);
 633
 634         gfs2_assert_withdraw(sdp,
 635                              sdp->sd_log_num_buf + sdp->sd_log_num_jdata ==
 636                              sdp->sd_log_commited_buf +
 637                              sdp->sd_log_commited_databuf);
 638         gfs2_assert_withdraw(sdp,
 639                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 640
 641         sdp->sd_log_flush_head = sdp->sd_log_head;
 642         sdp->sd_log_flush_wrapped = 0;
 643         ai->ai_first = sdp->sd_log_flush_head;
 644
 645         lops_before_commit(sdp);
 646         if (!list_empty(&sdp->sd_log_flush_list))
 647                 log_flush_commit(sdp);
 648         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 649                 gfs2_log_lock(sdp);
 650                 sdp->sd_log_blks_free--; /* Adjust for unreserved buffer */
 651                 gfs2_log_unlock(sdp);
 652                 log_write_header(sdp, 0, PULL);
 653         }
 654         lops_after_commit(sdp, ai);
 655
 656         gfs2_log_lock(sdp);
 657         sdp->sd_log_head = sdp->sd_log_flush_head;
 658         sdp->sd_log_blks_reserved = 0;
 659         sdp->sd_log_commited_buf = 0;
 660         sdp->sd_log_commited_databuf = 0;
 661         sdp->sd_log_commited_revoke = 0;
 662
 663         if (!list_empty(&ai->ai_ail1_list)) {
 664                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 665                 ai = NULL;
 666         }
 667         gfs2_log_unlock(sdp);
 668
 669         sdp->sd_vfs->s_dirt = 0;
 670         up_write(&sdp->sd_log_flush_lock);
 671
 672         kfree(ai);
 673 }
 674
 675 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 676 {
 677         unsigned int reserved;
 678         unsigned int old;
 679
 680         gfs2_log_lock(sdp);
 681
 682         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 683         sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
 684                 tr->tr_num_databuf_rm;
 685         gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
 686                              (((int)sdp->sd_log_commited_databuf) >= 0));
 687         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 688         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 689         reserved = calc_reserved(sdp);
 690         old = sdp->sd_log_blks_free;
 691         sdp->sd_log_blks_free += tr->tr_reserved -
 692                                  (reserved - sdp->sd_log_blks_reserved);
 693
 694         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 695         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <=
 696                              sdp->sd_jdesc->jd_blocks);
 697
 698         sdp->sd_log_blks_reserved = reserved;
 699
 700         gfs2_log_unlock(sdp);
 701 }
 702
 703 /**
 704  * gfs2_log_commit - Commit a transaction to the log
 705  * @sdp: the filesystem
 706  * @tr: the transaction
 707  *
 708  * Returns: errno
 709  */
 710
 711 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 712 {
 713         log_refund(sdp, tr);
 714         lops_incore_commit(sdp, tr);
 715
 716         sdp->sd_vfs->s_dirt = 1;
 717         up_read(&sdp->sd_log_flush_lock);
 718
 719         gfs2_log_lock(sdp);
 720         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks))
 721                 wake_up_process(sdp->sd_logd_process);
 722         gfs2_log_unlock(sdp);
 723 }
 724
 725 /**
 726  * gfs2_log_shutdown - write a shutdown header into a journal
 727  * @sdp: the filesystem
 728  *
 729  */
 730
 731 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 732 {
 733         down_write(&sdp->sd_log_flush_lock);
 734
 735         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 736         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 737         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 738         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
 739         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 740         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 741         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 742         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 743
 744         sdp->sd_log_flush_head = sdp->sd_log_head;
 745         sdp->sd_log_flush_wrapped = 0;
 746
 747         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
 748                          (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
 749
 750         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
 751         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 752         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 753
 754         sdp->sd_log_head = sdp->sd_log_flush_head;
 755         sdp->sd_log_tail = sdp->sd_log_head;
 756
 757         up_write(&sdp->sd_log_flush_lock);
 758 }
 759
 760
 761 /**
 762  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 763  * @sdp: the filesystem
 764  *
 765  */
 766
 767 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 768 {
 769         gfs2_log_flush(sdp, NULL);
 770         for (;;) {
 771                 gfs2_ail1_start(sdp, DIO_ALL);
 772                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 773                         break;
 774                 msleep(10);
 775         }
 776 }
 777