git.oblomov.eu Git - linux-2.6/blob - fs/gfs2/meta_io.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 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 v.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/mm.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/writeback.h>
  18 #include <linux/swap.h>
  19 #include <linux/delay.h>
  20 #include <linux/gfs2_ondisk.h>
  21 #include <asm/semaphore.h>
  22
  23 #include "gfs2.h"
  24 #include "lm_interface.h"
  25 #include "incore.h"
  26 #include "glock.h"
  27 #include "glops.h"
  28 #include "inode.h"
  29 #include "log.h"
  30 #include "lops.h"
  31 #include "meta_io.h"
  32 #include "rgrp.h"
  33 #include "trans.h"
  34 #include "util.h"
  35
  36 #define buffer_busy(bh) \
  37 ((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned)))
  38 #define buffer_in_io(bh) \
  39 ((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock)))
  40
  41 static int aspace_get_block(struct inode *inode, sector_t lblock,
  42                             struct buffer_head *bh_result, int create)
  43 {
  44         gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
  45         return -EOPNOTSUPP;
  46 }
  47
  48 static int gfs2_aspace_writepage(struct page *page,
  49                                  struct writeback_control *wbc)
  50 {
  51         return block_write_full_page(page, aspace_get_block, wbc);
  52 }
  53
  54 /**
  55  * stuck_releasepage - We're stuck in gfs2_releasepage().  Print stuff out.
  56  * @bh: the buffer we're stuck on
  57  *
  58  */
  59
  60 static void stuck_releasepage(struct buffer_head *bh)
  61 {
  62         struct inode *inode = bh->b_page->mapping->host;
  63         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
  64         struct gfs2_bufdata *bd = bh->b_private;
  65         struct gfs2_glock *gl;
  66
  67         fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode);
  68         fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n",
  69                 (uint64_t)bh->b_blocknr, atomic_read(&bh->b_count));
  70         fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh));
  71         fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL");
  72
  73         if (!bd)
  74                 return;
  75
  76         gl = bd->bd_gl;
  77
  78         fs_warn(sdp, "gl = (%u, %llu)\n",
  79                 gl->gl_name.ln_type, gl->gl_name.ln_number);
  80
  81         fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n",
  82                 (list_empty(&bd->bd_list_tr)) ? "no" : "yes",
  83                 (list_empty(&bd->bd_le.le_list)) ? "no" : "yes");
  84
  85         if (gl->gl_ops == &gfs2_inode_glops) {
  86                 struct gfs2_inode *ip = gl->gl_object;
  87                 unsigned int x;
  88
  89                 if (!ip)
  90                         return;
  91
  92                 fs_warn(sdp, "ip = %llu %llu\n",
  93                         ip->i_num.no_formal_ino, ip->i_num.no_addr);
  94                 fs_warn(sdp, "ip->i_count = %d, ip->i_vnode = %s\n",
  95                         atomic_read(&ip->i_count),
  96                         (ip->i_vnode) ? "!NULL" : "NULL");
  97
  98                 for (x = 0; x < GFS2_MAX_META_HEIGHT; x++)
  99                         fs_warn(sdp, "ip->i_cache[%u] = %s\n",
 100                                 x, (ip->i_cache[x]) ? "!NULL" : "NULL");
 101         }
 102 }
 103
 104 /**
 105  * gfs2_aspace_releasepage - free the metadata associated with a page
 106  * @page: the page that's being released
 107  * @gfp_mask: passed from Linux VFS, ignored by us
 108  *
 109  * Call try_to_free_buffers() if the buffers in this page can be
 110  * released.
 111  *
 112  * Returns: 0
 113  */
 114
 115 static int gfs2_aspace_releasepage(struct page *page, gfp_t gfp_mask)
 116 {
 117         struct inode *aspace = page->mapping->host;
 118         struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
 119         struct buffer_head *bh, *head;
 120         struct gfs2_bufdata *bd;
 121         unsigned long t;
 122
 123         if (!page_has_buffers(page))
 124                 goto out;
 125
 126         head = bh = page_buffers(page);
 127         do {
 128                 t = jiffies;
 129
 130                 while (atomic_read(&bh->b_count)) {
 131                         if (atomic_read(&aspace->i_writecount)) {
 132                                 if (time_after_eq(jiffies, t +
 133                                     gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
 134                                         stuck_releasepage(bh);
 135                                         t = jiffies;
 136                                 }
 137
 138                                 yield();
 139                                 continue;
 140                         }
 141
 142                         return 0;
 143                 }
 144
 145                 gfs2_assert_warn(sdp, !buffer_pinned(bh));
 146
 147                 bd = bh->b_private;
 148                 if (bd) {
 149                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
 150                         gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
 151                         gfs2_assert_warn(sdp, list_empty(&bd->bd_le.le_list));
 152                         gfs2_assert_warn(sdp, !bd->bd_ail);
 153                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 154                         bh->b_private = NULL;
 155                 }
 156
 157                 bh = bh->b_this_page;
 158         }
 159         while (bh != head);
 160
 161  out:
 162         return try_to_free_buffers(page);
 163 }
 164
 165 static struct address_space_operations aspace_aops = {
 166         .writepage = gfs2_aspace_writepage,
 167         .releasepage = gfs2_aspace_releasepage,
 168 };
 169
 170 /**
 171  * gfs2_aspace_get - Create and initialize a struct inode structure
 172  * @sdp: the filesystem the aspace is in
 173  *
 174  * Right now a struct inode is just a struct inode.  Maybe Linux
 175  * will supply a more lightweight address space construct (that works)
 176  * in the future.
 177  *
 178  * Make sure pages/buffers in this aspace aren't in high memory.
 179  *
 180  * Returns: the aspace
 181  */
 182
 183 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
 184 {
 185         struct inode *aspace;
 186
 187         aspace = new_inode(sdp->sd_vfs);
 188         if (aspace) {
 189                 mapping_set_gfp_mask(aspace->i_mapping, GFP_KERNEL);
 190                 aspace->i_mapping->a_ops = &aspace_aops;
 191                 aspace->i_size = ~0ULL;
 192                 aspace->u.generic_ip = NULL;
 193                 insert_inode_hash(aspace);
 194         }
 195         return aspace;
 196 }
 197
 198 void gfs2_aspace_put(struct inode *aspace)
 199 {
 200         remove_inode_hash(aspace);
 201         iput(aspace);
 202 }
 203
 204 /**
 205  * gfs2_ail1_start_one - Start I/O on a part of the AIL
 206  * @sdp: the filesystem
 207  * @tr: the part of the AIL
 208  *
 209  */
 210
 211 void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 212 {
 213         struct gfs2_bufdata *bd, *s;
 214         struct buffer_head *bh;
 215         int retry;
 216
 217         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
 218
 219         do {
 220                 retry = 0;
 221
 222                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 223                                                  bd_ail_st_list) {
 224                         bh = bd->bd_bh;
 225
 226                         gfs2_assert(sdp, bd->bd_ail == ai);
 227
 228                         if (!buffer_busy(bh)) {
 229                                 if (!buffer_uptodate(bh))
 230                                         gfs2_io_error_bh(sdp, bh);
 231                                 list_move(&bd->bd_ail_st_list,
 232                                           &ai->ai_ail2_list);
 233                                 continue;
 234                         }
 235
 236                         if (!buffer_dirty(bh))
 237                                 continue;
 238
 239                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 240
 241                         gfs2_log_unlock(sdp);
 242                         wait_on_buffer(bh);
 243                         ll_rw_block(WRITE, 1, &bh);
 244                         gfs2_log_lock(sdp);
 245
 246                         retry = 1;
 247                         break;
 248                 }
 249         } while (retry);
 250 }
 251
 252 /**
 253  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 254  * @sdp: the filesystem
 255  * @ai: the AIL entry
 256  *
 257  */
 258
 259 int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 260 {
 261         struct gfs2_bufdata *bd, *s;
 262         struct buffer_head *bh;
 263
 264         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 265                                          bd_ail_st_list) {
 266                 bh = bd->bd_bh;
 267
 268                 gfs2_assert(sdp, bd->bd_ail == ai);
 269
 270                 if (buffer_busy(bh)) {
 271                         if (flags & DIO_ALL)
 272                                 continue;
 273                         else
 274                                 break;
 275                 }
 276
 277                 if (!buffer_uptodate(bh))
 278                         gfs2_io_error_bh(sdp, bh);
 279
 280                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 281         }
 282
 283         return list_empty(&ai->ai_ail1_list);
 284 }
 285
 286 /**
 287  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 288  * @sdp: the filesystem
 289  * @ai: the AIL entry
 290  *
 291  */
 292
 293 void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 294 {
 295         struct list_head *head = &ai->ai_ail2_list;
 296         struct gfs2_bufdata *bd;
 297
 298         while (!list_empty(head)) {
 299                 bd = list_entry(head->prev, struct gfs2_bufdata,
 300                                 bd_ail_st_list);
 301                 gfs2_assert(sdp, bd->bd_ail == ai);
 302                 bd->bd_ail = NULL;
 303                 list_del(&bd->bd_ail_st_list);
 304                 list_del(&bd->bd_ail_gl_list);
 305                 atomic_dec(&bd->bd_gl->gl_ail_count);
 306                 brelse(bd->bd_bh);
 307         }
 308 }
 309
 310 /**
 311  * ail_empty_gl - remove all buffers for a given lock from the AIL
 312  * @gl: the glock
 313  *
 314  * None of the buffers should be dirty, locked, or pinned.
 315  */
 316
 317 void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 318 {
 319         struct gfs2_sbd *sdp = gl->gl_sbd;
 320         unsigned int blocks;
 321         struct list_head *head = &gl->gl_ail_list;
 322         struct gfs2_bufdata *bd;
 323         struct buffer_head *bh;
 324         uint64_t blkno;
 325         int error;
 326
 327         blocks = atomic_read(&gl->gl_ail_count);
 328         if (!blocks)
 329                 return;
 330
 331         error = gfs2_trans_begin(sdp, 0, blocks);
 332         if (gfs2_assert_withdraw(sdp, !error))
 333                 return;
 334
 335         gfs2_log_lock(sdp);
 336         while (!list_empty(head)) {
 337                 bd = list_entry(head->next, struct gfs2_bufdata,
 338                                 bd_ail_gl_list);
 339                 bh = bd->bd_bh;
 340                 blkno = bh->b_blocknr;
 341                 gfs2_assert_withdraw(sdp, !buffer_busy(bh));
 342
 343                 bd->bd_ail = NULL;
 344                 list_del(&bd->bd_ail_st_list);
 345                 list_del(&bd->bd_ail_gl_list);
 346                 atomic_dec(&gl->gl_ail_count);
 347                 brelse(bh);
 348                 gfs2_log_unlock(sdp);
 349
 350                 gfs2_trans_add_revoke(sdp, blkno);
 351
 352                 gfs2_log_lock(sdp);
 353         }
 354         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 355         gfs2_log_unlock(sdp);
 356
 357         gfs2_trans_end(sdp);
 358         gfs2_log_flush(sdp, NULL);
 359 }
 360
 361 /**
 362  * gfs2_meta_inval - Invalidate all buffers associated with a glock
 363  * @gl: the glock
 364  *
 365  */
 366
 367 void gfs2_meta_inval(struct gfs2_glock *gl)
 368 {
 369         struct gfs2_sbd *sdp = gl->gl_sbd;
 370         struct inode *aspace = gl->gl_aspace;
 371         struct address_space *mapping = gl->gl_aspace->i_mapping;
 372
 373         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 374
 375         atomic_inc(&aspace->i_writecount);
 376         truncate_inode_pages(mapping, 0);
 377         atomic_dec(&aspace->i_writecount);
 378
 379         gfs2_assert_withdraw(sdp, !mapping->nrpages);
 380 }
 381
 382 /**
 383  * gfs2_meta_sync - Sync all buffers associated with a glock
 384  * @gl: The glock
 385  * @flags: DIO_START | DIO_WAIT
 386  *
 387  */
 388
 389 void gfs2_meta_sync(struct gfs2_glock *gl, int flags)
 390 {
 391         struct address_space *mapping = gl->gl_aspace->i_mapping;
 392         int error = 0;
 393
 394         if (flags & DIO_START)
 395                 filemap_fdatawrite(mapping);
 396         if (!error && (flags & DIO_WAIT))
 397                 error = filemap_fdatawait(mapping);
 398
 399         if (error)
 400                 gfs2_io_error(gl->gl_sbd);
 401 }
 402
 403 /**
 404  * getbuf - Get a buffer with a given address space
 405  * @sdp: the filesystem
 406  * @aspace: the address space
 407  * @blkno: the block number (filesystem scope)
 408  * @create: 1 if the buffer should be created
 409  *
 410  * Returns: the buffer
 411  */
 412
 413 static struct buffer_head *getbuf(struct gfs2_sbd *sdp, struct inode *aspace,
 414                                   uint64_t blkno, int create)
 415 {
 416         struct page *page;
 417         struct buffer_head *bh;
 418         unsigned int shift;
 419         unsigned long index;
 420         unsigned int bufnum;
 421
 422         shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 423         index = blkno >> shift;             /* convert block to page */
 424         bufnum = blkno - (index << shift);  /* block buf index within page */
 425
 426         if (create) {
 427                 for (;;) {
 428                         page = grab_cache_page(aspace->i_mapping, index);
 429                         if (page)
 430                                 break;
 431                         yield();
 432                 }
 433         } else {
 434                 page = find_lock_page(aspace->i_mapping, index);
 435                 if (!page)
 436                         return NULL;
 437         }
 438
 439         if (!page_has_buffers(page))
 440                 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 441
 442         /* Locate header for our buffer within our page */
 443         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 444                 /* Do nothing */;
 445         get_bh(bh);
 446
 447         if (!buffer_mapped(bh))
 448                 map_bh(bh, sdp->sd_vfs, blkno);
 449
 450         unlock_page(page);
 451         mark_page_accessed(page);
 452         page_cache_release(page);
 453
 454         return bh;
 455 }
 456
 457 static void meta_prep_new(struct buffer_head *bh)
 458 {
 459         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 460
 461         lock_buffer(bh);
 462         clear_buffer_dirty(bh);
 463         set_buffer_uptodate(bh);
 464         unlock_buffer(bh);
 465
 466         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 467 }
 468
 469 /**
 470  * gfs2_meta_new - Get a block
 471  * @gl: The glock associated with this block
 472  * @blkno: The block number
 473  *
 474  * Returns: The buffer
 475  */
 476
 477 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, uint64_t blkno)
 478 {
 479         struct buffer_head *bh;
 480         bh = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 481         meta_prep_new(bh);
 482         return bh;
 483 }
 484
 485 /**
 486  * gfs2_meta_read - Read a block from disk
 487  * @gl: The glock covering the block
 488  * @blkno: The block number
 489  * @flags: flags to gfs2_dreread()
 490  * @bhp: the place where the buffer is returned (NULL on failure)
 491  *
 492  * Returns: errno
 493  */
 494
 495 int gfs2_meta_read(struct gfs2_glock *gl, uint64_t blkno, int flags,
 496                    struct buffer_head **bhp)
 497 {
 498         int error;
 499
 500         *bhp = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 501         error = gfs2_meta_reread(gl->gl_sbd, *bhp, flags);
 502         if (error)
 503                 brelse(*bhp);
 504
 505         return error;
 506 }
 507
 508 /**
 509  * gfs2_meta_reread - Reread a block from disk
 510  * @sdp: the filesystem
 511  * @bh: The block to read
 512  * @flags: Flags that control the read
 513  *
 514  * Returns: errno
 515  */
 516
 517 int gfs2_meta_reread(struct gfs2_sbd *sdp, struct buffer_head *bh, int flags)
 518 {
 519         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 520                 return -EIO;
 521
 522         if (flags & DIO_FORCE)
 523                 clear_buffer_uptodate(bh);
 524
 525         if ((flags & DIO_START) && !buffer_uptodate(bh))
 526                 ll_rw_block(READ, 1, &bh);
 527
 528         if (flags & DIO_WAIT) {
 529                 wait_on_buffer(bh);
 530
 531                 if (!buffer_uptodate(bh)) {
 532                         struct gfs2_trans *tr = current->journal_info;
 533                         if (tr && tr->tr_touched)
 534                                 gfs2_io_error_bh(sdp, bh);
 535                         return -EIO;
 536                 }
 537                 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 538                         return -EIO;
 539         }
 540
 541         return 0;
 542 }
 543
 544 /**
 545  * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
 546  * @gl: the glock the buffer belongs to
 547  * @bh: The buffer to be attached to
 548  * @meta: Flag to indicate whether its metadata or not
 549  */
 550
 551 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
 552                          int meta)
 553 {
 554         struct gfs2_bufdata *bd;
 555
 556         if (meta)
 557                 lock_page(bh->b_page);
 558
 559         if (bh->b_private) {
 560                 if (meta)
 561                         unlock_page(bh->b_page);
 562                 return;
 563         }
 564
 565         bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
 566         memset(bd, 0, sizeof(struct gfs2_bufdata));
 567
 568         bd->bd_bh = bh;
 569         bd->bd_gl = gl;
 570
 571         INIT_LIST_HEAD(&bd->bd_list_tr);
 572         if (meta) {
 573                 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
 574         } else {
 575                 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
 576                 get_bh(bh);
 577         }
 578         bh->b_private = bd;
 579
 580         if (meta)
 581                 unlock_page(bh->b_page);
 582 }
 583
 584 /**
 585  * gfs2_pin - Pin a buffer in memory
 586  * @sdp: the filesystem the buffer belongs to
 587  * @bh: The buffer to be pinned
 588  *
 589  */
 590
 591 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
 592 {
 593         struct gfs2_bufdata *bd = bh->b_private;
 594
 595         gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
 596
 597         if (test_set_buffer_pinned(bh))
 598                 gfs2_assert_withdraw(sdp, 0);
 599
 600         wait_on_buffer(bh);
 601
 602         /* If this buffer is in the AIL and it has already been written
 603            to in-place disk block, remove it from the AIL. */
 604
 605         gfs2_log_lock(sdp);
 606         if (bd->bd_ail && !buffer_in_io(bh))
 607                 list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
 608         gfs2_log_unlock(sdp);
 609
 610         clear_buffer_dirty(bh);
 611         wait_on_buffer(bh);
 612
 613         if (!buffer_uptodate(bh))
 614                 gfs2_io_error_bh(sdp, bh);
 615
 616         get_bh(bh);
 617 }
 618
 619 /**
 620  * gfs2_unpin - Unpin a buffer
 621  * @sdp: the filesystem the buffer belongs to
 622  * @bh: The buffer to unpin
 623  * @ai:
 624  *
 625  */
 626
 627 void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
 628                 struct gfs2_ail *ai)
 629 {
 630         struct gfs2_bufdata *bd = bh->b_private;
 631
 632         gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
 633
 634         if (!buffer_pinned(bh))
 635                 gfs2_assert_withdraw(sdp, 0);
 636
 637         mark_buffer_dirty(bh);
 638         clear_buffer_pinned(bh);
 639
 640         gfs2_log_lock(sdp);
 641         if (bd->bd_ail) {
 642                 list_del(&bd->bd_ail_st_list);
 643                 brelse(bh);
 644         } else {
 645                 struct gfs2_glock *gl = bd->bd_gl;
 646                 list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
 647                 atomic_inc(&gl->gl_ail_count);
 648         }
 649         bd->bd_ail = ai;
 650         list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 651         gfs2_log_unlock(sdp);
 652 }
 653
 654 /**
 655  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 656  * @ip: the inode who owns the buffers
 657  * @bstart: the first buffer in the run
 658  * @blen: the number of buffers in the run
 659  *
 660  */
 661
 662 void gfs2_meta_wipe(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
 663 {
 664         struct gfs2_sbd *sdp = ip->i_sbd;
 665         struct inode *aspace = ip->i_gl->gl_aspace;
 666         struct buffer_head *bh;
 667
 668         while (blen) {
 669                 bh = getbuf(sdp, aspace, bstart, NO_CREATE);
 670                 if (bh) {
 671                         struct gfs2_bufdata *bd = bh->b_private;
 672
 673                         if (test_clear_buffer_pinned(bh)) {
 674                                 struct gfs2_trans *tr = current->journal_info;
 675                                 gfs2_log_lock(sdp);
 676                                 list_del_init(&bd->bd_le.le_list);
 677                                 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
 678                                 sdp->sd_log_num_buf--;
 679                                 gfs2_log_unlock(sdp);
 680                                 tr->tr_num_buf_rm++;
 681                                 brelse(bh);
 682                         }
 683                         if (bd) {
 684                                 gfs2_log_lock(sdp);
 685                                 if (bd->bd_ail) {
 686                                         uint64_t blkno = bh->b_blocknr;
 687                                         bd->bd_ail = NULL;
 688                                         list_del(&bd->bd_ail_st_list);
 689                                         list_del(&bd->bd_ail_gl_list);
 690                                         atomic_dec(&bd->bd_gl->gl_ail_count);
 691                                         brelse(bh);
 692                                         gfs2_log_unlock(sdp);
 693                                         gfs2_trans_add_revoke(sdp, blkno);
 694                                 } else
 695                                         gfs2_log_unlock(sdp);
 696                         }
 697
 698                         lock_buffer(bh);
 699                         clear_buffer_dirty(bh);
 700                         clear_buffer_uptodate(bh);
 701                         unlock_buffer(bh);
 702
 703                         brelse(bh);
 704                 }
 705
 706                 bstart++;
 707                 blen--;
 708         }
 709 }
 710
 711 /**
 712  * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
 713  * @ip: The GFS2 inode
 714  *
 715  * This releases buffers that are in the most-recently-used array of
 716  * blocks used for indirect block addressing for this inode.
 717  */
 718
 719 void gfs2_meta_cache_flush(struct gfs2_inode *ip)
 720 {
 721         struct buffer_head **bh_slot;
 722         unsigned int x;
 723
 724         spin_lock(&ip->i_spin);
 725
 726         for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
 727                 bh_slot = &ip->i_cache[x];
 728                 if (!*bh_slot)
 729                         break;
 730                 brelse(*bh_slot);
 731                 *bh_slot = NULL;
 732         }
 733
 734         spin_unlock(&ip->i_spin);
 735 }
 736
 737 /**
 738  * gfs2_meta_indirect_buffer - Get a metadata buffer
 739  * @ip: The GFS2 inode
 740  * @height: The level of this buf in the metadata (indir addr) tree (if any)
 741  * @num: The block number (device relative) of the buffer
 742  * @new: Non-zero if we may create a new buffer
 743  * @bhp: the buffer is returned here
 744  *
 745  * Try to use the gfs2_inode's MRU metadata tree cache.
 746  *
 747  * Returns: errno
 748  */
 749
 750 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, uint64_t num,
 751                               int new, struct buffer_head **bhp)
 752 {
 753         struct buffer_head *bh, **bh_slot = ip->i_cache + height;
 754         int error;
 755
 756         spin_lock(&ip->i_spin);
 757         bh = *bh_slot;
 758         if (bh) {
 759                 if (bh->b_blocknr == num)
 760                         get_bh(bh);
 761                 else
 762                         bh = NULL;
 763         }
 764         spin_unlock(&ip->i_spin);
 765
 766         if (bh) {
 767                 if (new)
 768                         meta_prep_new(bh);
 769                 else {
 770                         error = gfs2_meta_reread(ip->i_sbd, bh,
 771                                                  DIO_START | DIO_WAIT);
 772                         if (error) {
 773                                 brelse(bh);
 774                                 return error;
 775                         }
 776                 }
 777         } else {
 778                 if (new)
 779                         bh = gfs2_meta_new(ip->i_gl, num);
 780                 else {
 781                         error = gfs2_meta_read(ip->i_gl, num,
 782                                                DIO_START | DIO_WAIT, &bh);
 783                         if (error)
 784                                 return error;
 785                 }
 786
 787                 spin_lock(&ip->i_spin);
 788                 if (*bh_slot != bh) {
 789                         brelse(*bh_slot);
 790                         *bh_slot = bh;
 791                         get_bh(bh);
 792                 }
 793                 spin_unlock(&ip->i_spin);
 794         }
 795
 796         if (new) {
 797                 if (gfs2_assert_warn(ip->i_sbd, height)) {
 798                         brelse(bh);
 799                         return -EIO;
 800                 }
 801                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 802                 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
 803                 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 804
 805         } else if (gfs2_metatype_check(ip->i_sbd, bh,
 806                              (height) ? GFS2_METATYPE_IN : GFS2_METATYPE_DI)) {
 807                 brelse(bh);
 808                 return -EIO;
 809         }
 810
 811         *bhp = bh;
 812
 813         return 0;
 814 }
 815
 816 /**
 817  * gfs2_meta_ra - start readahead on an extent of a file
 818  * @gl: the glock the blocks belong to
 819  * @dblock: the starting disk block
 820  * @extlen: the number of blocks in the extent
 821  *
 822  */
 823
 824 void gfs2_meta_ra(struct gfs2_glock *gl, uint64_t dblock, uint32_t extlen)
 825 {
 826         struct gfs2_sbd *sdp = gl->gl_sbd;
 827         struct inode *aspace = gl->gl_aspace;
 828         struct buffer_head *first_bh, *bh;
 829         uint32_t max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 830                           sdp->sd_sb.sb_bsize_shift;
 831         int error;
 832
 833         if (!extlen || !max_ra)
 834                 return;
 835         if (extlen > max_ra)
 836                 extlen = max_ra;
 837
 838         first_bh = getbuf(sdp, aspace, dblock, CREATE);
 839
 840         if (buffer_uptodate(first_bh))
 841                 goto out;
 842         if (!buffer_locked(first_bh)) {
 843                 error = gfs2_meta_reread(sdp, first_bh, DIO_START);
 844                 if (error)
 845                         goto out;
 846         }
 847
 848         dblock++;
 849         extlen--;
 850
 851         while (extlen) {
 852                 bh = getbuf(sdp, aspace, dblock, CREATE);
 853
 854                 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
 855                         error = gfs2_meta_reread(sdp, bh, DIO_START);
 856                         brelse(bh);
 857                         if (error)
 858                                 goto out;
 859                 } else
 860                         brelse(bh);
 861
 862                 dblock++;
 863                 extlen--;
 864
 865                 if (buffer_uptodate(first_bh))
 866                         break;
 867         }
 868
 869  out:
 870         brelse(first_bh);
 871 }
 872
 873 /**
 874  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 875  * @sdp: the filesystem
 876  *
 877  */
 878
 879 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 880 {
 881         gfs2_log_flush(sdp, NULL);
 882         for (;;) {
 883                 gfs2_ail1_start(sdp, DIO_ALL);
 884                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 885                         break;
 886                 msleep(10);
 887         }
 888 }
 889