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                 brelse(bd->bd_bh);
 241         }
 242 }
 243
 244 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 245 {
 246         struct gfs2_ail *ai, *safe;
 247         unsigned int old_tail = sdp->sd_log_tail;
 248         int wrap = (new_tail < old_tail);
 249         int a, b, rm;
 250
 251         gfs2_log_lock(sdp);
 252
 253         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 254                 a = (old_tail <= ai->ai_first);
 255                 b = (ai->ai_first < new_tail);
 256                 rm = (wrap) ? (a || b) : (a && b);
 257                 if (!rm)
 258                         continue;
 259
 260                 gfs2_ail2_empty_one(sdp, ai);
 261                 list_del(&ai->ai_list);
 262                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 263                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 264                 kfree(ai);
 265         }
 266
 267         gfs2_log_unlock(sdp);
 268 }
 269
 270 /**
 271  * gfs2_log_reserve - Make a log reservation
 272  * @sdp: The GFS2 superblock
 273  * @blks: The number of blocks to reserve
 274  *
 275  * Note that we never give out the last few blocks of the journal. Thats
 276  * due to the fact that there is a small number of header blocks
 277  * associated with each log flush. The exact number can't be known until
 278  * flush time, so we ensure that we have just enough free blocks at all
 279  * times to avoid running out during a log flush.
 280  *
 281  * Returns: errno
 282  */
 283
 284 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 285 {
 286         unsigned int try = 0;
 287         unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
 288
 289         if (gfs2_assert_warn(sdp, blks) ||
 290             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 291                 return -EINVAL;
 292
 293         mutex_lock(&sdp->sd_log_reserve_mutex);
 294         gfs2_log_lock(sdp);
 295         while(sdp->sd_log_blks_free <= (blks + reserved_blks)) {
 296                 gfs2_log_unlock(sdp);
 297                 gfs2_ail1_empty(sdp, 0);
 298                 gfs2_log_flush(sdp, NULL);
 299
 300                 if (try++)
 301                         gfs2_ail1_start(sdp, 0);
 302                 gfs2_log_lock(sdp);
 303         }
 304         sdp->sd_log_blks_free -= blks;
 305         gfs2_log_unlock(sdp);
 306         mutex_unlock(&sdp->sd_log_reserve_mutex);
 307
 308         down_read(&sdp->sd_log_flush_lock);
 309
 310         return 0;
 311 }
 312
 313 /**
 314  * gfs2_log_release - Release a given number of log blocks
 315  * @sdp: The GFS2 superblock
 316  * @blks: The number of blocks
 317  *
 318  */
 319
 320 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 321 {
 322
 323         gfs2_log_lock(sdp);
 324         sdp->sd_log_blks_free += blks;
 325         gfs2_assert_withdraw(sdp,
 326                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 327         gfs2_log_unlock(sdp);
 328         up_read(&sdp->sd_log_flush_lock);
 329 }
 330
 331 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 332 {
 333         struct inode *inode = sdp->sd_jdesc->jd_inode;
 334         int error;
 335         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 336
 337         bh_map.b_size = 1 << inode->i_blkbits;
 338         error = gfs2_block_map(inode, lbn, 0, &bh_map);
 339         if (error || !bh_map.b_blocknr)
 340                 printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error,
 341                        (unsigned long long)bh_map.b_blocknr, lbn);
 342         gfs2_assert_withdraw(sdp, !error && bh_map.b_blocknr);
 343
 344         return bh_map.b_blocknr;
 345 }
 346
 347 /**
 348  * log_distance - Compute distance between two journal blocks
 349  * @sdp: The GFS2 superblock
 350  * @newer: The most recent journal block of the pair
 351  * @older: The older journal block of the pair
 352  *
 353  *   Compute the distance (in the journal direction) between two
 354  *   blocks in the journal
 355  *
 356  * Returns: the distance in blocks
 357  */
 358
 359 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 360                                         unsigned int older)
 361 {
 362         int dist;
 363
 364         dist = newer - older;
 365         if (dist < 0)
 366                 dist += sdp->sd_jdesc->jd_blocks;
 367
 368         return dist;
 369 }
 370
 371 /**
 372  * calc_reserved - Calculate the number of blocks to reserve when
 373  *                 refunding a transaction's unused buffers.
 374  * @sdp: The GFS2 superblock
 375  *
 376  * This is complex.  We need to reserve room for all our currently used
 377  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
 378  * all our journaled data buffers for journaled files (e.g. files in the
 379  * meta_fs like rindex, or files for which chattr +j was done.)
 380  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
 381  * will count it as free space (sd_log_blks_free) and corruption will follow.
 382  *
 383  * We can have metadata bufs and jdata bufs in the same journal.  So each
 384  * type gets its own log header, for which we need to reserve a block.
 385  * In fact, each type has the potential for needing more than one header
 386  * in cases where we have more buffers than will fit on a journal page.
 387  * Metadata journal entries take up half the space of journaled buffer entries.
 388  * Thus, metadata entries have buf_limit (502) and journaled buffers have
 389  * databuf_limit (251) before they cause a wrap around.
 390  *
 391  * Also, we need to reserve blocks for revoke journal entries and one for an
 392  * overall header for the lot.
 393  *
 394  * Returns: the number of blocks reserved
 395  */
 396 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 397 {
 398         unsigned int reserved = 0;
 399         unsigned int mbuf_limit, metabufhdrs_needed;
 400         unsigned int dbuf_limit, databufhdrs_needed;
 401         unsigned int revokes = 0;
 402
 403         mbuf_limit = buf_limit(sdp);
 404         metabufhdrs_needed = (sdp->sd_log_commited_buf +
 405                               (mbuf_limit - 1)) / mbuf_limit;
 406         dbuf_limit = databuf_limit(sdp);
 407         databufhdrs_needed = (sdp->sd_log_commited_databuf +
 408                               (dbuf_limit - 1)) / dbuf_limit;
 409
 410         if (sdp->sd_log_commited_revoke)
 411                 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 412                                           sizeof(u64));
 413
 414         reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
 415                 sdp->sd_log_commited_databuf + databufhdrs_needed +
 416                 revokes;
 417         /* One for the overall header */
 418         if (reserved)
 419                 reserved++;
 420         return reserved;
 421 }
 422
 423 static unsigned int current_tail(struct gfs2_sbd *sdp)
 424 {
 425         struct gfs2_ail *ai;
 426         unsigned int tail;
 427
 428         gfs2_log_lock(sdp);
 429
 430         if (list_empty(&sdp->sd_ail1_list)) {
 431                 tail = sdp->sd_log_head;
 432         } else {
 433                 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
 434                 tail = ai->ai_first;
 435         }
 436
 437         gfs2_log_unlock(sdp);
 438
 439         return tail;
 440 }
 441
 442 static inline void log_incr_head(struct gfs2_sbd *sdp)
 443 {
 444         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 445                 gfs2_assert_withdraw(sdp, sdp->sd_log_flush_head == sdp->sd_log_head);
 446
 447         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 448                 sdp->sd_log_flush_head = 0;
 449                 sdp->sd_log_flush_wrapped = 1;
 450         }
 451 }
 452
 453 /**
 454  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 455  * @sdp: The GFS2 superblock
 456  *
 457  * Returns: the buffer_head
 458  */
 459
 460 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 461 {
 462         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 463         struct gfs2_log_buf *lb;
 464         struct buffer_head *bh;
 465
 466         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 467         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 468
 469         bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
 470         lock_buffer(bh);
 471         memset(bh->b_data, 0, bh->b_size);
 472         set_buffer_uptodate(bh);
 473         clear_buffer_dirty(bh);
 474         unlock_buffer(bh);
 475
 476         log_incr_head(sdp);
 477
 478         return bh;
 479 }
 480
 481 /**
 482  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 483  * @sdp: the filesystem
 484  * @data: the data the buffer_head should point to
 485  *
 486  * Returns: the log buffer descriptor
 487  */
 488
 489 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 490                                       struct buffer_head *real)
 491 {
 492         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 493         struct gfs2_log_buf *lb;
 494         struct buffer_head *bh;
 495
 496         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
 497         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
 498         lb->lb_real = real;
 499
 500         bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 501         atomic_set(&bh->b_count, 1);
 502         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
 503         set_bh_page(bh, real->b_page, bh_offset(real));
 504         bh->b_blocknr = blkno;
 505         bh->b_size = sdp->sd_sb.sb_bsize;
 506         bh->b_bdev = sdp->sd_vfs->s_bdev;
 507
 508         log_incr_head(sdp);
 509
 510         return bh;
 511 }
 512
 513 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 514 {
 515         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 516
 517         ail2_empty(sdp, new_tail);
 518
 519         gfs2_log_lock(sdp);
 520         sdp->sd_log_blks_free += dist;
 521         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 522         gfs2_log_unlock(sdp);
 523
 524         sdp->sd_log_tail = new_tail;
 525 }
 526
 527 /**
 528  * log_write_header - Get and initialize a journal header buffer
 529  * @sdp: The GFS2 superblock
 530  *
 531  * Returns: the initialized log buffer descriptor
 532  */
 533
 534 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 535 {
 536         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 537         struct buffer_head *bh;
 538         struct gfs2_log_header *lh;
 539         unsigned int tail;
 540         u32 hash;
 541
 542         bh = sb_getblk(sdp->sd_vfs, blkno);
 543         lock_buffer(bh);
 544         memset(bh->b_data, 0, bh->b_size);
 545         set_buffer_uptodate(bh);
 546         clear_buffer_dirty(bh);
 547         unlock_buffer(bh);
 548
 549         gfs2_ail1_empty(sdp, 0);
 550         tail = current_tail(sdp);
 551
 552         lh = (struct gfs2_log_header *)bh->b_data;
 553         memset(lh, 0, sizeof(struct gfs2_log_header));
 554         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 555         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 556         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 557         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
 558         lh->lh_flags = cpu_to_be32(flags);
 559         lh->lh_tail = cpu_to_be32(tail);
 560         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
 561         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 562         lh->lh_hash = cpu_to_be32(hash);
 563
 564         set_buffer_dirty(bh);
 565         if (sync_dirty_buffer(bh))
 566                 gfs2_io_error_bh(sdp, bh);
 567         brelse(bh);
 568
 569         if (sdp->sd_log_tail != tail)
 570                 log_pull_tail(sdp, tail);
 571         else
 572                 gfs2_assert_withdraw(sdp, !pull);
 573
 574         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 575         log_incr_head(sdp);
 576 }
 577
 578 static void log_flush_commit(struct gfs2_sbd *sdp)
 579 {
 580         struct list_head *head = &sdp->sd_log_flush_list;
 581         struct gfs2_log_buf *lb;
 582         struct buffer_head *bh;
 583         int flushcount = 0;
 584
 585         while (!list_empty(head)) {
 586                 lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
 587                 list_del(&lb->lb_list);
 588                 bh = lb->lb_bh;
 589
 590                 wait_on_buffer(bh);
 591                 if (!buffer_uptodate(bh))
 592                         gfs2_io_error_bh(sdp, bh);
 593                 if (lb->lb_real) {
 594                         while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
 595                                 schedule();
 596                         free_buffer_head(bh);
 597                 } else
 598                         brelse(bh);
 599                 kfree(lb);
 600                 flushcount++;
 601         }
 602
 603         /* If nothing was journaled, the header is unplanned and unwanted. */
 604         if (flushcount) {
 605                 log_write_header(sdp, 0, 0);
 606         } else {
 607                 unsigned int tail;
 608                 tail = current_tail(sdp);
 609
 610                 gfs2_ail1_empty(sdp, 0);
 611                 if (sdp->sd_log_tail != tail)
 612                         log_pull_tail(sdp, tail);
 613         }
 614 }
 615
 616 /**
 617  * gfs2_log_flush - flush incore transaction(s)
 618  * @sdp: the filesystem
 619  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 620  *
 621  */
 622
 623 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 624 {
 625         struct gfs2_ail *ai;
 626
 627         down_write(&sdp->sd_log_flush_lock);
 628
 629         if (gl) {
 630                 gfs2_log_lock(sdp);
 631                 if (list_empty(&gl->gl_le.le_list)) {
 632                         gfs2_log_unlock(sdp);
 633                         up_write(&sdp->sd_log_flush_lock);
 634                         return;
 635                 }
 636                 gfs2_log_unlock(sdp);
 637         }
 638
 639         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 640         INIT_LIST_HEAD(&ai->ai_ail1_list);
 641         INIT_LIST_HEAD(&ai->ai_ail2_list);
 642
 643         gfs2_assert_withdraw(sdp,
 644                              sdp->sd_log_num_buf + sdp->sd_log_num_jdata ==
 645                              sdp->sd_log_commited_buf +
 646                              sdp->sd_log_commited_databuf);
 647         gfs2_assert_withdraw(sdp,
 648                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 649
 650         sdp->sd_log_flush_head = sdp->sd_log_head;
 651         sdp->sd_log_flush_wrapped = 0;
 652         ai->ai_first = sdp->sd_log_flush_head;
 653
 654         lops_before_commit(sdp);
 655         if (!list_empty(&sdp->sd_log_flush_list))
 656                 log_flush_commit(sdp);
 657         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 658                 gfs2_log_lock(sdp);
 659                 sdp->sd_log_blks_free--; /* Adjust for unreserved buffer */
 660                 gfs2_log_unlock(sdp);
 661                 log_write_header(sdp, 0, PULL);
 662         }
 663         lops_after_commit(sdp, ai);
 664
 665         gfs2_log_lock(sdp);
 666         sdp->sd_log_head = sdp->sd_log_flush_head;
 667         sdp->sd_log_blks_reserved = 0;
 668         sdp->sd_log_commited_buf = 0;
 669         sdp->sd_log_commited_databuf = 0;
 670         sdp->sd_log_commited_revoke = 0;
 671
 672         if (!list_empty(&ai->ai_ail1_list)) {
 673                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 674                 ai = NULL;
 675         }
 676         gfs2_log_unlock(sdp);
 677
 678         sdp->sd_vfs->s_dirt = 0;
 679         up_write(&sdp->sd_log_flush_lock);
 680
 681         kfree(ai);
 682 }
 683
 684 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 685 {
 686         unsigned int reserved;
 687         unsigned int old;
 688
 689         gfs2_log_lock(sdp);
 690
 691         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 692         sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
 693                 tr->tr_num_databuf_rm;
 694         gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
 695                              (((int)sdp->sd_log_commited_databuf) >= 0));
 696         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 697         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 698         reserved = calc_reserved(sdp);
 699         old = sdp->sd_log_blks_free;
 700         sdp->sd_log_blks_free += tr->tr_reserved -
 701                                  (reserved - sdp->sd_log_blks_reserved);
 702
 703         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 704         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <=
 705                              sdp->sd_jdesc->jd_blocks);
 706
 707         sdp->sd_log_blks_reserved = reserved;
 708
 709         gfs2_log_unlock(sdp);
 710 }
 711
 712 /**
 713  * gfs2_log_commit - Commit a transaction to the log
 714  * @sdp: the filesystem
 715  * @tr: the transaction
 716  *
 717  * Returns: errno
 718  */
 719
 720 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 721 {
 722         log_refund(sdp, tr);
 723         lops_incore_commit(sdp, tr);
 724
 725         sdp->sd_vfs->s_dirt = 1;
 726         up_read(&sdp->sd_log_flush_lock);
 727
 728         gfs2_log_lock(sdp);
 729         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks))
 730                 wake_up_process(sdp->sd_logd_process);
 731         gfs2_log_unlock(sdp);
 732 }
 733
 734 /**
 735  * gfs2_log_shutdown - write a shutdown header into a journal
 736  * @sdp: the filesystem
 737  *
 738  */
 739
 740 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 741 {
 742         down_write(&sdp->sd_log_flush_lock);
 743
 744         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 745         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 746         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 747         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
 748         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 749         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 750         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 751         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 752
 753         sdp->sd_log_flush_head = sdp->sd_log_head;
 754         sdp->sd_log_flush_wrapped = 0;
 755
 756         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
 757                          (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
 758
 759         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
 760         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 761         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 762
 763         sdp->sd_log_head = sdp->sd_log_flush_head;
 764         sdp->sd_log_tail = sdp->sd_log_head;
 765
 766         up_write(&sdp->sd_log_flush_lock);
 767 }
 768
 769
 770 /**
 771  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 772  * @sdp: the filesystem
 773  *
 774  */
 775
 776 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 777 {
 778         gfs2_log_flush(sdp, NULL);
 779         for (;;) {
 780                 gfs2_ail1_start(sdp, DIO_ALL);
 781                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 782                         break;
 783                 msleep(10);
 784         }
 785 }
 786