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_remove_from_ail - Remove an entry from the ail lists, updating counters
  64  * @mapping: The associated mapping (maybe NULL)
  65  * @bd: The gfs2_bufdata to remove
  66  *
  67  * The log lock _must_ be held when calling this function
  68  *
  69  */
  70
  71 void gfs2_remove_from_ail(struct address_space *mapping, struct gfs2_bufdata *bd)
  72 {
  73         bd->bd_ail = NULL;
  74         list_del_init(&bd->bd_ail_st_list);
  75         list_del_init(&bd->bd_ail_gl_list);
  76         atomic_dec(&bd->bd_gl->gl_ail_count);
  77         if (mapping)
  78                 gfs2_meta_cache_flush(GFS2_I(mapping->host));
  79         brelse(bd->bd_bh);
  80 }
  81
  82 /**
  83  * gfs2_ail1_start_one - Start I/O on a part of the AIL
  84  * @sdp: the filesystem
  85  * @tr: the part of the AIL
  86  *
  87  */
  88
  89 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
  90 {
  91         struct gfs2_bufdata *bd, *s;
  92         struct buffer_head *bh;
  93         int retry;
  94
  95         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
  96
  97         do {
  98                 retry = 0;
  99
 100                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 101                                                  bd_ail_st_list) {
 102                         bh = bd->bd_bh;
 103
 104                         gfs2_assert(sdp, bd->bd_ail == ai);
 105
 106                         if (!buffer_busy(bh)) {
 107                                 if (!buffer_uptodate(bh))
 108                                         gfs2_io_error_bh(sdp, bh);
 109                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 110                                 continue;
 111                         }
 112
 113                         if (!buffer_dirty(bh))
 114                                 continue;
 115
 116                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 117
 118                         get_bh(bh);
 119                         gfs2_log_unlock(sdp);
 120                         lock_buffer(bh);
 121                         if (test_clear_buffer_dirty(bh)) {
 122                                 bh->b_end_io = end_buffer_write_sync;
 123                                 submit_bh(WRITE, bh);
 124                         } else {
 125                                 unlock_buffer(bh);
 126                                 brelse(bh);
 127                         }
 128                         gfs2_log_lock(sdp);
 129
 130                         retry = 1;
 131                         break;
 132                 }
 133         } while (retry);
 134 }
 135
 136 /**
 137  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 138  * @sdp: the filesystem
 139  * @ai: the AIL entry
 140  *
 141  */
 142
 143 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 144 {
 145         struct gfs2_bufdata *bd, *s;
 146         struct buffer_head *bh;
 147
 148         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 149                                          bd_ail_st_list) {
 150                 bh = bd->bd_bh;
 151
 152                 gfs2_assert(sdp, bd->bd_ail == ai);
 153
 154                 if (buffer_busy(bh)) {
 155                         if (flags & DIO_ALL)
 156                                 continue;
 157                         else
 158                                 break;
 159                 }
 160
 161                 if (!buffer_uptodate(bh))
 162                         gfs2_io_error_bh(sdp, bh);
 163
 164                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 165         }
 166
 167         return list_empty(&ai->ai_ail1_list);
 168 }
 169
 170 static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
 171 {
 172         struct list_head *head;
 173         u64 sync_gen;
 174         struct list_head *first;
 175         struct gfs2_ail *first_ai, *ai, *tmp;
 176         int done = 0;
 177
 178         gfs2_log_lock(sdp);
 179         head = &sdp->sd_ail1_list;
 180         if (list_empty(head)) {
 181                 gfs2_log_unlock(sdp);
 182                 return;
 183         }
 184         sync_gen = sdp->sd_ail_sync_gen++;
 185
 186         first = head->prev;
 187         first_ai = list_entry(first, struct gfs2_ail, ai_list);
 188         first_ai->ai_sync_gen = sync_gen;
 189         gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */
 190
 191         if (flags & DIO_ALL)
 192                 first = NULL;
 193
 194         while(!done) {
 195                 if (first && (head->prev != first ||
 196                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
 197                         break;
 198
 199                 done = 1;
 200                 list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) {
 201                         if (ai->ai_sync_gen >= sync_gen)
 202                                 continue;
 203                         ai->ai_sync_gen = sync_gen;
 204                         gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
 205                         done = 0;
 206                         break;
 207                 }
 208         }
 209
 210         gfs2_log_unlock(sdp);
 211 }
 212
 213 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
 214 {
 215         struct gfs2_ail *ai, *s;
 216         int ret;
 217
 218         gfs2_log_lock(sdp);
 219
 220         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
 221                 if (gfs2_ail1_empty_one(sdp, ai, flags))
 222                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
 223                 else if (!(flags & DIO_ALL))
 224                         break;
 225         }
 226
 227         ret = list_empty(&sdp->sd_ail1_list);
 228
 229         gfs2_log_unlock(sdp);
 230
 231         return ret;
 232 }
 233
 234
 235 /**
 236  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 237  * @sdp: the filesystem
 238  * @ai: the AIL entry
 239  *
 240  */
 241
 242 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 243 {
 244         struct list_head *head = &ai->ai_ail2_list;
 245         struct gfs2_bufdata *bd;
 246
 247         while (!list_empty(head)) {
 248                 bd = list_entry(head->prev, struct gfs2_bufdata,
 249                                 bd_ail_st_list);
 250                 gfs2_assert(sdp, bd->bd_ail == ai);
 251                 gfs2_remove_from_ail(bd->bd_bh->b_page->mapping, bd);
 252         }
 253 }
 254
 255 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
 256 {
 257         struct gfs2_ail *ai, *safe;
 258         unsigned int old_tail = sdp->sd_log_tail;
 259         int wrap = (new_tail < old_tail);
 260         int a, b, rm;
 261
 262         gfs2_log_lock(sdp);
 263
 264         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
 265                 a = (old_tail <= ai->ai_first);
 266                 b = (ai->ai_first < new_tail);
 267                 rm = (wrap) ? (a || b) : (a && b);
 268                 if (!rm)
 269                         continue;
 270
 271                 gfs2_ail2_empty_one(sdp, ai);
 272                 list_del(&ai->ai_list);
 273                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
 274                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
 275                 kfree(ai);
 276         }
 277
 278         gfs2_log_unlock(sdp);
 279 }
 280
 281 /**
 282  * gfs2_log_reserve - Make a log reservation
 283  * @sdp: The GFS2 superblock
 284  * @blks: The number of blocks to reserve
 285  *
 286  * Note that we never give out the last few blocks of the journal. Thats
 287  * due to the fact that there is a small number of header blocks
 288  * associated with each log flush. The exact number can't be known until
 289  * flush time, so we ensure that we have just enough free blocks at all
 290  * times to avoid running out during a log flush.
 291  *
 292  * Returns: errno
 293  */
 294
 295 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
 296 {
 297         unsigned int try = 0;
 298         unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
 299
 300         if (gfs2_assert_warn(sdp, blks) ||
 301             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
 302                 return -EINVAL;
 303
 304         mutex_lock(&sdp->sd_log_reserve_mutex);
 305         gfs2_log_lock(sdp);
 306         while(sdp->sd_log_blks_free <= (blks + reserved_blks)) {
 307                 gfs2_log_unlock(sdp);
 308                 gfs2_ail1_empty(sdp, 0);
 309                 gfs2_log_flush(sdp, NULL);
 310
 311                 if (try++)
 312                         gfs2_ail1_start(sdp, 0);
 313                 gfs2_log_lock(sdp);
 314         }
 315         sdp->sd_log_blks_free -= blks;
 316         gfs2_log_unlock(sdp);
 317         mutex_unlock(&sdp->sd_log_reserve_mutex);
 318
 319         down_read(&sdp->sd_log_flush_lock);
 320
 321         return 0;
 322 }
 323
 324 /**
 325  * gfs2_log_release - Release a given number of log blocks
 326  * @sdp: The GFS2 superblock
 327  * @blks: The number of blocks
 328  *
 329  */
 330
 331 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
 332 {
 333
 334         gfs2_log_lock(sdp);
 335         sdp->sd_log_blks_free += blks;
 336         gfs2_assert_withdraw(sdp,
 337                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 338         gfs2_log_unlock(sdp);
 339         up_read(&sdp->sd_log_flush_lock);
 340 }
 341
 342 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
 343 {
 344         struct inode *inode = sdp->sd_jdesc->jd_inode;
 345         int error;
 346         struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
 347
 348         bh_map.b_size = 1 << inode->i_blkbits;
 349         error = gfs2_block_map(inode, lbn, 0, &bh_map);
 350         if (error || !bh_map.b_blocknr)
 351                 printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error,
 352                        (unsigned long long)bh_map.b_blocknr, lbn);
 353         gfs2_assert_withdraw(sdp, !error && bh_map.b_blocknr);
 354
 355         return bh_map.b_blocknr;
 356 }
 357
 358 /**
 359  * log_distance - Compute distance between two journal blocks
 360  * @sdp: The GFS2 superblock
 361  * @newer: The most recent journal block of the pair
 362  * @older: The older journal block of the pair
 363  *
 364  *   Compute the distance (in the journal direction) between two
 365  *   blocks in the journal
 366  *
 367  * Returns: the distance in blocks
 368  */
 369
 370 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
 371                                         unsigned int older)
 372 {
 373         int dist;
 374
 375         dist = newer - older;
 376         if (dist < 0)
 377                 dist += sdp->sd_jdesc->jd_blocks;
 378
 379         return dist;
 380 }
 381
 382 /**
 383  * calc_reserved - Calculate the number of blocks to reserve when
 384  *                 refunding a transaction's unused buffers.
 385  * @sdp: The GFS2 superblock
 386  *
 387  * This is complex.  We need to reserve room for all our currently used
 388  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
 389  * all our journaled data buffers for journaled files (e.g. files in the
 390  * meta_fs like rindex, or files for which chattr +j was done.)
 391  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
 392  * will count it as free space (sd_log_blks_free) and corruption will follow.
 393  *
 394  * We can have metadata bufs and jdata bufs in the same journal.  So each
 395  * type gets its own log header, for which we need to reserve a block.
 396  * In fact, each type has the potential for needing more than one header
 397  * in cases where we have more buffers than will fit on a journal page.
 398  * Metadata journal entries take up half the space of journaled buffer entries.
 399  * Thus, metadata entries have buf_limit (502) and journaled buffers have
 400  * databuf_limit (251) before they cause a wrap around.
 401  *
 402  * Also, we need to reserve blocks for revoke journal entries and one for an
 403  * overall header for the lot.
 404  *
 405  * Returns: the number of blocks reserved
 406  */
 407 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
 408 {
 409         unsigned int reserved = 0;
 410         unsigned int mbuf_limit, metabufhdrs_needed;
 411         unsigned int dbuf_limit, databufhdrs_needed;
 412         unsigned int revokes = 0;
 413
 414         mbuf_limit = buf_limit(sdp);
 415         metabufhdrs_needed = (sdp->sd_log_commited_buf +
 416                               (mbuf_limit - 1)) / mbuf_limit;
 417         dbuf_limit = databuf_limit(sdp);
 418         databufhdrs_needed = (sdp->sd_log_commited_databuf +
 419                               (dbuf_limit - 1)) / dbuf_limit;
 420
 421         if (sdp->sd_log_commited_revoke)
 422                 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
 423                                           sizeof(u64));
 424
 425         reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
 426                 sdp->sd_log_commited_databuf + databufhdrs_needed +
 427                 revokes;
 428         /* One for the overall header */
 429         if (reserved)
 430                 reserved++;
 431         return reserved;
 432 }
 433
 434 static unsigned int current_tail(struct gfs2_sbd *sdp)
 435 {
 436         struct gfs2_ail *ai;
 437         unsigned int tail;
 438
 439         gfs2_log_lock(sdp);
 440
 441         if (list_empty(&sdp->sd_ail1_list)) {
 442                 tail = sdp->sd_log_head;
 443         } else {
 444                 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
 445                 tail = ai->ai_first;
 446         }
 447
 448         gfs2_log_unlock(sdp);
 449
 450         return tail;
 451 }
 452
 453 void gfs2_log_incr_head(struct gfs2_sbd *sdp)
 454 {
 455         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
 456                 BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head);
 457
 458         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
 459                 sdp->sd_log_flush_head = 0;
 460                 sdp->sd_log_flush_wrapped = 1;
 461         }
 462 }
 463
 464 /**
 465  * gfs2_log_write_endio - End of I/O for a log buffer
 466  * @bh: The buffer head
 467  * @uptodate: I/O Status
 468  *
 469  */
 470
 471 static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
 472 {
 473         struct gfs2_sbd *sdp = bh->b_private;
 474         bh->b_private = NULL;
 475
 476         end_buffer_write_sync(bh, uptodate);
 477         if (atomic_dec_and_test(&sdp->sd_log_in_flight))
 478                 wake_up(&sdp->sd_log_flush_wait);
 479 }
 480
 481 /**
 482  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 483  * @sdp: The GFS2 superblock
 484  *
 485  * Returns: the buffer_head
 486  */
 487
 488 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 489 {
 490         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 491         struct buffer_head *bh;
 492
 493         bh = sb_getblk(sdp->sd_vfs, blkno);
 494         lock_buffer(bh);
 495         memset(bh->b_data, 0, bh->b_size);
 496         set_buffer_uptodate(bh);
 497         clear_buffer_dirty(bh);
 498         gfs2_log_incr_head(sdp);
 499         atomic_inc(&sdp->sd_log_in_flight);
 500         bh->b_private = sdp;
 501         bh->b_end_io = gfs2_log_write_endio;
 502
 503         return bh;
 504 }
 505
 506 /**
 507  * gfs2_fake_write_endio -
 508  * @bh: The buffer head
 509  * @uptodate: The I/O Status
 510  *
 511  */
 512
 513 static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
 514 {
 515         struct buffer_head *real_bh = bh->b_private;
 516         struct gfs2_bufdata *bd = real_bh->b_private;
 517         struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
 518
 519         end_buffer_write_sync(bh, uptodate);
 520         free_buffer_head(bh);
 521         unlock_buffer(real_bh);
 522         brelse(real_bh);
 523         if (atomic_dec_and_test(&sdp->sd_log_in_flight))
 524                 wake_up(&sdp->sd_log_flush_wait);
 525 }
 526
 527 /**
 528  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 529  * @sdp: the filesystem
 530  * @data: the data the buffer_head should point to
 531  *
 532  * Returns: the log buffer descriptor
 533  */
 534
 535 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 536                                       struct buffer_head *real)
 537 {
 538         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 539         struct buffer_head *bh;
 540
 541         bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 542         atomic_set(&bh->b_count, 1);
 543         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
 544         set_bh_page(bh, real->b_page, bh_offset(real));
 545         bh->b_blocknr = blkno;
 546         bh->b_size = sdp->sd_sb.sb_bsize;
 547         bh->b_bdev = sdp->sd_vfs->s_bdev;
 548         bh->b_private = real;
 549         bh->b_end_io = gfs2_fake_write_endio;
 550
 551         gfs2_log_incr_head(sdp);
 552         atomic_inc(&sdp->sd_log_in_flight);
 553
 554         return bh;
 555 }
 556
 557 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 558 {
 559         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 560
 561         ail2_empty(sdp, new_tail);
 562
 563         gfs2_log_lock(sdp);
 564         sdp->sd_log_blks_free += dist;
 565         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 566         gfs2_log_unlock(sdp);
 567
 568         sdp->sd_log_tail = new_tail;
 569 }
 570
 571 /**
 572  * log_write_header - Get and initialize a journal header buffer
 573  * @sdp: The GFS2 superblock
 574  *
 575  * Returns: the initialized log buffer descriptor
 576  */
 577
 578 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 579 {
 580         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 581         struct buffer_head *bh;
 582         struct gfs2_log_header *lh;
 583         unsigned int tail;
 584         u32 hash;
 585
 586         bh = sb_getblk(sdp->sd_vfs, blkno);
 587         lock_buffer(bh);
 588         memset(bh->b_data, 0, bh->b_size);
 589         set_buffer_uptodate(bh);
 590         clear_buffer_dirty(bh);
 591         unlock_buffer(bh);
 592
 593         gfs2_ail1_empty(sdp, 0);
 594         tail = current_tail(sdp);
 595
 596         lh = (struct gfs2_log_header *)bh->b_data;
 597         memset(lh, 0, sizeof(struct gfs2_log_header));
 598         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 599         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 600         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 601         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
 602         lh->lh_flags = cpu_to_be32(flags);
 603         lh->lh_tail = cpu_to_be32(tail);
 604         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
 605         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 606         lh->lh_hash = cpu_to_be32(hash);
 607
 608         set_buffer_dirty(bh);
 609         if (sync_dirty_buffer(bh))
 610                 gfs2_io_error_bh(sdp, bh);
 611         brelse(bh);
 612
 613         if (sdp->sd_log_tail != tail)
 614                 log_pull_tail(sdp, tail);
 615         else
 616                 gfs2_assert_withdraw(sdp, !pull);
 617
 618         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 619         gfs2_log_incr_head(sdp);
 620 }
 621
 622 static void log_flush_commit(struct gfs2_sbd *sdp)
 623 {
 624         DEFINE_WAIT(wait);
 625
 626         if (atomic_read(&sdp->sd_log_in_flight)) {
 627                 do {
 628                         prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
 629                                         TASK_UNINTERRUPTIBLE);
 630                         if (atomic_read(&sdp->sd_log_in_flight))
 631                                 io_schedule();
 632                 } while(atomic_read(&sdp->sd_log_in_flight));
 633                 finish_wait(&sdp->sd_log_flush_wait, &wait);
 634         }
 635
 636         log_write_header(sdp, 0, 0);
 637 }
 638
 639 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 640 {
 641         struct gfs2_bufdata *bd;
 642         struct buffer_head *bh;
 643         LIST_HEAD(written);
 644
 645         gfs2_log_lock(sdp);
 646         while (!list_empty(&sdp->sd_log_le_ordered)) {
 647                 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
 648                 list_move(&bd->bd_le.le_list, &written);
 649                 bh = bd->bd_bh;
 650                 if (!buffer_dirty(bh))
 651                         continue;
 652                 get_bh(bh);
 653                 gfs2_log_unlock(sdp);
 654                 lock_buffer(bh);
 655                 if (test_clear_buffer_dirty(bh)) {
 656                         bh->b_end_io = end_buffer_write_sync;
 657                         submit_bh(WRITE, bh);
 658                 } else {
 659                         unlock_buffer(bh);
 660                         brelse(bh);
 661                 }
 662                 gfs2_log_lock(sdp);
 663         }
 664         list_splice(&written, &sdp->sd_log_le_ordered);
 665         gfs2_log_unlock(sdp);
 666 }
 667
 668 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
 669 {
 670         struct gfs2_bufdata *bd;
 671         struct buffer_head *bh;
 672
 673         gfs2_log_lock(sdp);
 674         while (!list_empty(&sdp->sd_log_le_ordered)) {
 675                 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list);
 676                 bh = bd->bd_bh;
 677                 if (buffer_locked(bh)) {
 678                         get_bh(bh);
 679                         gfs2_log_unlock(sdp);
 680                         wait_on_buffer(bh);
 681                         brelse(bh);
 682                         gfs2_log_lock(sdp);
 683                         continue;
 684                 }
 685                 list_del_init(&bd->bd_le.le_list);
 686         }
 687         gfs2_log_unlock(sdp);
 688 }
 689
 690 /**
 691  * gfs2_log_flush - flush incore transaction(s)
 692  * @sdp: the filesystem
 693  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 694  *
 695  */
 696
 697 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 698 {
 699         struct gfs2_ail *ai;
 700
 701         down_write(&sdp->sd_log_flush_lock);
 702
 703         if (gl) {
 704                 gfs2_log_lock(sdp);
 705                 if (list_empty(&gl->gl_le.le_list)) {
 706                         gfs2_log_unlock(sdp);
 707                         up_write(&sdp->sd_log_flush_lock);
 708                         return;
 709                 }
 710                 gfs2_log_unlock(sdp);
 711         }
 712
 713         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 714         INIT_LIST_HEAD(&ai->ai_ail1_list);
 715         INIT_LIST_HEAD(&ai->ai_ail2_list);
 716
 717         if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
 718                 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
 719                        sdp->sd_log_commited_buf);
 720                 gfs2_assert_withdraw(sdp, 0);
 721         }
 722         if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
 723                 printk(KERN_INFO "GFS2: log databuf %u %u\n",
 724                        sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
 725                 gfs2_assert_withdraw(sdp, 0);
 726         }
 727         gfs2_assert_withdraw(sdp,
 728                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 729
 730         sdp->sd_log_flush_head = sdp->sd_log_head;
 731         sdp->sd_log_flush_wrapped = 0;
 732         ai->ai_first = sdp->sd_log_flush_head;
 733
 734         gfs2_ordered_write(sdp);
 735         lops_before_commit(sdp);
 736         gfs2_ordered_wait(sdp);
 737
 738         if (sdp->sd_log_head != sdp->sd_log_flush_head)
 739                 log_flush_commit(sdp);
 740         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 741                 gfs2_log_lock(sdp);
 742                 sdp->sd_log_blks_free--; /* Adjust for unreserved buffer */
 743                 gfs2_log_unlock(sdp);
 744                 log_write_header(sdp, 0, PULL);
 745         }
 746         lops_after_commit(sdp, ai);
 747
 748         gfs2_log_lock(sdp);
 749         sdp->sd_log_head = sdp->sd_log_flush_head;
 750         sdp->sd_log_blks_reserved = 0;
 751         sdp->sd_log_commited_buf = 0;
 752         sdp->sd_log_commited_databuf = 0;
 753         sdp->sd_log_commited_revoke = 0;
 754
 755         if (!list_empty(&ai->ai_ail1_list)) {
 756                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 757                 ai = NULL;
 758         }
 759         gfs2_log_unlock(sdp);
 760
 761         sdp->sd_vfs->s_dirt = 0;
 762         up_write(&sdp->sd_log_flush_lock);
 763
 764         kfree(ai);
 765 }
 766
 767 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 768 {
 769         unsigned int reserved;
 770         unsigned int old;
 771
 772         gfs2_log_lock(sdp);
 773
 774         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 775         sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
 776                 tr->tr_num_databuf_rm;
 777         gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
 778                              (((int)sdp->sd_log_commited_databuf) >= 0));
 779         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 780         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 781         reserved = calc_reserved(sdp);
 782         old = sdp->sd_log_blks_free;
 783         sdp->sd_log_blks_free += tr->tr_reserved -
 784                                  (reserved - sdp->sd_log_blks_reserved);
 785
 786         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 787         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <=
 788                              sdp->sd_jdesc->jd_blocks);
 789
 790         sdp->sd_log_blks_reserved = reserved;
 791
 792         gfs2_log_unlock(sdp);
 793 }
 794
 795 /**
 796  * gfs2_log_commit - Commit a transaction to the log
 797  * @sdp: the filesystem
 798  * @tr: the transaction
 799  *
 800  * Returns: errno
 801  */
 802
 803 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 804 {
 805         log_refund(sdp, tr);
 806         lops_incore_commit(sdp, tr);
 807
 808         sdp->sd_vfs->s_dirt = 1;
 809         up_read(&sdp->sd_log_flush_lock);
 810
 811         gfs2_log_lock(sdp);
 812         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks))
 813                 wake_up_process(sdp->sd_logd_process);
 814         gfs2_log_unlock(sdp);
 815 }
 816
 817 /**
 818  * gfs2_log_shutdown - write a shutdown header into a journal
 819  * @sdp: the filesystem
 820  *
 821  */
 822
 823 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 824 {
 825         down_write(&sdp->sd_log_flush_lock);
 826
 827         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 828         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 829         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 830         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 831         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 832         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 833         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 834
 835         sdp->sd_log_flush_head = sdp->sd_log_head;
 836         sdp->sd_log_flush_wrapped = 0;
 837
 838         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
 839                          (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
 840
 841         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
 842         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 843         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 844
 845         sdp->sd_log_head = sdp->sd_log_flush_head;
 846         sdp->sd_log_tail = sdp->sd_log_head;
 847
 848         up_write(&sdp->sd_log_flush_lock);
 849 }
 850
 851
 852 /**
 853  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 854  * @sdp: the filesystem
 855  *
 856  */
 857
 858 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 859 {
 860         gfs2_log_flush(sdp, NULL);
 861         for (;;) {
 862                 gfs2_ail1_start(sdp, DIO_ALL);
 863                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 864                         break;
 865                 msleep(10);
 866         }
 867 }
 868