git.oblomov.eu Git - linux-2.6/blob - 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_sbd *sdp = GFS2_SB(real_bh->b_page->mapping->host);
 517
 518         end_buffer_write_sync(bh, uptodate);
 519         free_buffer_head(bh);
 520         unlock_buffer(real_bh);
 521         brelse(real_bh);
 522         if (atomic_dec_and_test(&sdp->sd_log_in_flight))
 523                 wake_up(&sdp->sd_log_flush_wait);
 524 }
 525
 526 /**
 527  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 528  * @sdp: the filesystem
 529  * @data: the data the buffer_head should point to
 530  *
 531  * Returns: the log buffer descriptor
 532  */
 533
 534 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
 535                                       struct buffer_head *real)
 536 {
 537         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 538         struct buffer_head *bh;
 539
 540         bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
 541         atomic_set(&bh->b_count, 1);
 542         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
 543         set_bh_page(bh, real->b_page, bh_offset(real));
 544         bh->b_blocknr = blkno;
 545         bh->b_size = sdp->sd_sb.sb_bsize;
 546         bh->b_bdev = sdp->sd_vfs->s_bdev;
 547         bh->b_private = real;
 548         bh->b_end_io = gfs2_fake_write_endio;
 549
 550         gfs2_log_incr_head(sdp);
 551         atomic_inc(&sdp->sd_log_in_flight);
 552
 553         return bh;
 554 }
 555
 556 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
 557 {
 558         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
 559
 560         ail2_empty(sdp, new_tail);
 561
 562         gfs2_log_lock(sdp);
 563         sdp->sd_log_blks_free += dist;
 564         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
 565         gfs2_log_unlock(sdp);
 566
 567         sdp->sd_log_tail = new_tail;
 568 }
 569
 570 /**
 571  * log_write_header - Get and initialize a journal header buffer
 572  * @sdp: The GFS2 superblock
 573  *
 574  * Returns: the initialized log buffer descriptor
 575  */
 576
 577 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 578 {
 579         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
 580         struct buffer_head *bh;
 581         struct gfs2_log_header *lh;
 582         unsigned int tail;
 583         u32 hash;
 584
 585         bh = sb_getblk(sdp->sd_vfs, blkno);
 586         lock_buffer(bh);
 587         memset(bh->b_data, 0, bh->b_size);
 588         set_buffer_uptodate(bh);
 589         clear_buffer_dirty(bh);
 590         unlock_buffer(bh);
 591
 592         gfs2_ail1_empty(sdp, 0);
 593         tail = current_tail(sdp);
 594
 595         lh = (struct gfs2_log_header *)bh->b_data;
 596         memset(lh, 0, sizeof(struct gfs2_log_header));
 597         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
 598         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
 599         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
 600         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
 601         lh->lh_flags = cpu_to_be32(flags);
 602         lh->lh_tail = cpu_to_be32(tail);
 603         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
 604         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
 605         lh->lh_hash = cpu_to_be32(hash);
 606
 607         set_buffer_dirty(bh);
 608         if (sync_dirty_buffer(bh))
 609                 gfs2_io_error_bh(sdp, bh);
 610         brelse(bh);
 611
 612         if (sdp->sd_log_tail != tail)
 613                 log_pull_tail(sdp, tail);
 614         else
 615                 gfs2_assert_withdraw(sdp, !pull);
 616
 617         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
 618         gfs2_log_incr_head(sdp);
 619 }
 620
 621 static void log_flush_commit(struct gfs2_sbd *sdp)
 622 {
 623         DEFINE_WAIT(wait);
 624
 625         if (atomic_read(&sdp->sd_log_in_flight)) {
 626                 do {
 627                         prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
 628                                         TASK_UNINTERRUPTIBLE);
 629                         if (atomic_read(&sdp->sd_log_in_flight))
 630                                 io_schedule();
 631                 } while(atomic_read(&sdp->sd_log_in_flight));
 632                 finish_wait(&sdp->sd_log_flush_wait, &wait);
 633         }
 634
 635         log_write_header(sdp, 0, 0);
 636 }
 637
 638 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 639 {
 640         struct gfs2_bufdata *bd;
 641         struct buffer_head *bh;
 642         LIST_HEAD(written);
 643
 644         gfs2_log_lock(sdp);
 645         while (!list_empty(&sdp->sd_log_le_ordered)) {
 646                 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
 647                 list_move(&bd->bd_le.le_list, &written);
 648                 bh = bd->bd_bh;
 649                 if (!buffer_dirty(bh))
 650                         continue;
 651                 get_bh(bh);
 652                 gfs2_log_unlock(sdp);
 653                 lock_buffer(bh);
 654                 if (test_clear_buffer_dirty(bh)) {
 655                         bh->b_end_io = end_buffer_write_sync;
 656                         submit_bh(WRITE, bh);
 657                 } else {
 658                         unlock_buffer(bh);
 659                         brelse(bh);
 660                 }
 661                 gfs2_log_lock(sdp);
 662         }
 663         list_splice(&written, &sdp->sd_log_le_ordered);
 664         gfs2_log_unlock(sdp);
 665 }
 666
 667 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
 668 {
 669         struct gfs2_bufdata *bd;
 670         struct buffer_head *bh;
 671
 672         gfs2_log_lock(sdp);
 673         while (!list_empty(&sdp->sd_log_le_ordered)) {
 674                 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list);
 675                 bh = bd->bd_bh;
 676                 if (buffer_locked(bh)) {
 677                         get_bh(bh);
 678                         gfs2_log_unlock(sdp);
 679                         wait_on_buffer(bh);
 680                         brelse(bh);
 681                         gfs2_log_lock(sdp);
 682                         continue;
 683                 }
 684                 list_del_init(&bd->bd_le.le_list);
 685         }
 686         gfs2_log_unlock(sdp);
 687 }
 688
 689 /**
 690  * gfs2_log_flush - flush incore transaction(s)
 691  * @sdp: the filesystem
 692  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 693  *
 694  */
 695
 696 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
 697 {
 698         struct gfs2_ail *ai;
 699
 700         down_write(&sdp->sd_log_flush_lock);
 701
 702         if (gl) {
 703                 gfs2_log_lock(sdp);
 704                 if (list_empty(&gl->gl_le.le_list)) {
 705                         gfs2_log_unlock(sdp);
 706                         up_write(&sdp->sd_log_flush_lock);
 707                         return;
 708                 }
 709                 gfs2_log_unlock(sdp);
 710         }
 711
 712         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
 713         INIT_LIST_HEAD(&ai->ai_ail1_list);
 714         INIT_LIST_HEAD(&ai->ai_ail2_list);
 715
 716         if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
 717                 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
 718                        sdp->sd_log_commited_buf);
 719                 gfs2_assert_withdraw(sdp, 0);
 720         }
 721         if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
 722                 printk(KERN_INFO "GFS2: log databuf %u %u\n",
 723                        sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
 724                 gfs2_assert_withdraw(sdp, 0);
 725         }
 726         gfs2_assert_withdraw(sdp,
 727                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
 728
 729         sdp->sd_log_flush_head = sdp->sd_log_head;
 730         sdp->sd_log_flush_wrapped = 0;
 731         ai->ai_first = sdp->sd_log_flush_head;
 732
 733         gfs2_ordered_write(sdp);
 734         lops_before_commit(sdp);
 735         gfs2_ordered_wait(sdp);
 736
 737         if (sdp->sd_log_head != sdp->sd_log_flush_head)
 738                 log_flush_commit(sdp);
 739         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
 740                 gfs2_log_lock(sdp);
 741                 sdp->sd_log_blks_free--; /* Adjust for unreserved buffer */
 742                 gfs2_log_unlock(sdp);
 743                 log_write_header(sdp, 0, PULL);
 744         }
 745         lops_after_commit(sdp, ai);
 746
 747         gfs2_log_lock(sdp);
 748         sdp->sd_log_head = sdp->sd_log_flush_head;
 749         sdp->sd_log_blks_reserved = 0;
 750         sdp->sd_log_commited_buf = 0;
 751         sdp->sd_log_commited_databuf = 0;
 752         sdp->sd_log_commited_revoke = 0;
 753
 754         if (!list_empty(&ai->ai_ail1_list)) {
 755                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
 756                 ai = NULL;
 757         }
 758         gfs2_log_unlock(sdp);
 759
 760         sdp->sd_vfs->s_dirt = 0;
 761         up_write(&sdp->sd_log_flush_lock);
 762
 763         kfree(ai);
 764 }
 765
 766 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 767 {
 768         unsigned int reserved;
 769         unsigned int old;
 770
 771         gfs2_log_lock(sdp);
 772
 773         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
 774         sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
 775                 tr->tr_num_databuf_rm;
 776         gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
 777                              (((int)sdp->sd_log_commited_databuf) >= 0));
 778         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
 779         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
 780         reserved = calc_reserved(sdp);
 781         old = sdp->sd_log_blks_free;
 782         sdp->sd_log_blks_free += tr->tr_reserved -
 783                                  (reserved - sdp->sd_log_blks_reserved);
 784
 785         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
 786         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free <=
 787                              sdp->sd_jdesc->jd_blocks);
 788
 789         sdp->sd_log_blks_reserved = reserved;
 790
 791         gfs2_log_unlock(sdp);
 792 }
 793
 794 /**
 795  * gfs2_log_commit - Commit a transaction to the log
 796  * @sdp: the filesystem
 797  * @tr: the transaction
 798  *
 799  * Returns: errno
 800  */
 801
 802 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
 803 {
 804         log_refund(sdp, tr);
 805         lops_incore_commit(sdp, tr);
 806
 807         sdp->sd_vfs->s_dirt = 1;
 808         up_read(&sdp->sd_log_flush_lock);
 809
 810         gfs2_log_lock(sdp);
 811         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks))
 812                 wake_up_process(sdp->sd_logd_process);
 813         gfs2_log_unlock(sdp);
 814 }
 815
 816 /**
 817  * gfs2_log_shutdown - write a shutdown header into a journal
 818  * @sdp: the filesystem
 819  *
 820  */
 821
 822 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
 823 {
 824         down_write(&sdp->sd_log_flush_lock);
 825
 826         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
 827         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
 828         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
 829         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
 830         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
 831         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
 832         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
 833
 834         sdp->sd_log_flush_head = sdp->sd_log_head;
 835         sdp->sd_log_flush_wrapped = 0;
 836
 837         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
 838                          (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
 839
 840         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
 841         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
 842         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
 843
 844         sdp->sd_log_head = sdp->sd_log_flush_head;
 845         sdp->sd_log_tail = sdp->sd_log_head;
 846
 847         up_write(&sdp->sd_log_flush_lock);
 848 }
 849
 850
 851 /**
 852  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 853  * @sdp: the filesystem
 854  *
 855  */
 856
 857 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 858 {
 859         gfs2_log_flush(sdp, NULL);
 860         for (;;) {
 861                 gfs2_ail1_start(sdp, DIO_ALL);
 862                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 863                         break;
 864                 msleep(10);
 865         }
 866 }
 867