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) 2004-2006 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 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
  22 #include "gfs2.h"
  23 #include "lm_interface.h"
  24 #include "incore.h"
  25 #include "glock.h"
  26 #include "glops.h"
  27 #include "inode.h"
  28 #include "log.h"
  29 #include "lops.h"
  30 #include "meta_io.h"
  31 #include "rgrp.h"
  32 #include "trans.h"
  33 #include "util.h"
  34
  35 #define buffer_busy(bh) \
  36 ((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned)))
  37 #define buffer_in_io(bh) \
  38 ((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock)))
  39
  40 static int aspace_get_block(struct inode *inode, sector_t lblock,
  41                             struct buffer_head *bh_result, int create)
  42 {
  43         gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
  44         return -EOPNOTSUPP;
  45 }
  46
  47 static int gfs2_aspace_writepage(struct page *page,
  48                                  struct writeback_control *wbc)
  49 {
  50         return block_write_full_page(page, aspace_get_block, wbc);
  51 }
  52
  53 /**
  54  * stuck_releasepage - We're stuck in gfs2_releasepage().  Print stuff out.
  55  * @bh: the buffer we're stuck on
  56  *
  57  */
  58
  59 static void stuck_releasepage(struct buffer_head *bh)
  60 {
  61         struct inode *inode = bh->b_page->mapping->host;
  62         struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
  63         struct gfs2_bufdata *bd = bh->b_private;
  64         struct gfs2_glock *gl;
  65
  66         fs_warn(sdp, "stuck in gfs2_releasepage() %p\n", inode);
  67         fs_warn(sdp, "blkno = %llu, bh->b_count = %d\n",
  68                 (unsigned long long)bh->b_blocknr, atomic_read(&bh->b_count));
  69         fs_warn(sdp, "pinned = %u\n", buffer_pinned(bh));
  70         fs_warn(sdp, "bh->b_private = %s\n", (bd) ? "!NULL" : "NULL");
  71
  72         if (!bd)
  73                 return;
  74
  75         gl = bd->bd_gl;
  76
  77         fs_warn(sdp, "gl = (%u, %llu)\n",
  78                 gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number);
  79
  80         fs_warn(sdp, "bd_list_tr = %s, bd_le.le_list = %s\n",
  81                 (list_empty(&bd->bd_list_tr)) ? "no" : "yes",
  82                 (list_empty(&bd->bd_le.le_list)) ? "no" : "yes");
  83
  84         if (gl->gl_ops == &gfs2_inode_glops) {
  85                 struct gfs2_inode *ip = gl->gl_object;
  86                 unsigned int x;
  87
  88                 if (!ip)
  89                         return;
  90
  91                 fs_warn(sdp, "ip = %llu %llu\n",
  92                         (unsigned long long)ip->i_num.no_formal_ino,
  93                         (unsigned long long)ip->i_num.no_addr);
  94
  95                 for (x = 0; x < GFS2_MAX_META_HEIGHT; x++)
  96                         fs_warn(sdp, "ip->i_cache[%u] = %s\n",
  97                                 x, (ip->i_cache[x]) ? "!NULL" : "NULL");
  98         }
  99 }
 100
 101 /**
 102  * gfs2_aspace_releasepage - free the metadata associated with a page
 103  * @page: the page that's being released
 104  * @gfp_mask: passed from Linux VFS, ignored by us
 105  *
 106  * Call try_to_free_buffers() if the buffers in this page can be
 107  * released.
 108  *
 109  * Returns: 0
 110  */
 111
 112 static int gfs2_aspace_releasepage(struct page *page, gfp_t gfp_mask)
 113 {
 114         struct inode *aspace = page->mapping->host;
 115         struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
 116         struct buffer_head *bh, *head;
 117         struct gfs2_bufdata *bd;
 118         unsigned long t;
 119
 120         if (!page_has_buffers(page))
 121                 goto out;
 122
 123         head = bh = page_buffers(page);
 124         do {
 125                 t = jiffies;
 126
 127                 while (atomic_read(&bh->b_count)) {
 128                         if (atomic_read(&aspace->i_writecount)) {
 129                                 if (time_after_eq(jiffies, t +
 130                                     gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
 131                                         stuck_releasepage(bh);
 132                                         t = jiffies;
 133                                 }
 134
 135                                 yield();
 136                                 continue;
 137                         }
 138
 139                         return 0;
 140                 }
 141
 142                 gfs2_assert_warn(sdp, !buffer_pinned(bh));
 143
 144                 bd = bh->b_private;
 145                 if (bd) {
 146                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
 147                         gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
 148                         gfs2_assert_warn(sdp, list_empty(&bd->bd_le.le_list));
 149                         gfs2_assert_warn(sdp, !bd->bd_ail);
 150                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 151                         bh->b_private = NULL;
 152                 }
 153
 154                 bh = bh->b_this_page;
 155         }
 156         while (bh != head);
 157
 158  out:
 159         return try_to_free_buffers(page);
 160 }
 161
 162 static const struct address_space_operations aspace_aops = {
 163         .writepage = gfs2_aspace_writepage,
 164         .releasepage = gfs2_aspace_releasepage,
 165 };
 166
 167 /**
 168  * gfs2_aspace_get - Create and initialize a struct inode structure
 169  * @sdp: the filesystem the aspace is in
 170  *
 171  * Right now a struct inode is just a struct inode.  Maybe Linux
 172  * will supply a more lightweight address space construct (that works)
 173  * in the future.
 174  *
 175  * Make sure pages/buffers in this aspace aren't in high memory.
 176  *
 177  * Returns: the aspace
 178  */
 179
 180 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
 181 {
 182         struct inode *aspace;
 183
 184         aspace = new_inode(sdp->sd_vfs);
 185         if (aspace) {
 186                 mapping_set_gfp_mask(aspace->i_mapping, GFP_KERNEL);
 187                 aspace->i_mapping->a_ops = &aspace_aops;
 188                 aspace->i_size = ~0ULL;
 189                 aspace->u.generic_ip = NULL;
 190                 insert_inode_hash(aspace);
 191         }
 192         return aspace;
 193 }
 194
 195 void gfs2_aspace_put(struct inode *aspace)
 196 {
 197         remove_inode_hash(aspace);
 198         iput(aspace);
 199 }
 200
 201 /**
 202  * gfs2_ail1_start_one - Start I/O on a part of the AIL
 203  * @sdp: the filesystem
 204  * @tr: the part of the AIL
 205  *
 206  */
 207
 208 void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 209 {
 210         struct gfs2_bufdata *bd, *s;
 211         struct buffer_head *bh;
 212         int retry;
 213
 214         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
 215
 216         do {
 217                 retry = 0;
 218
 219                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 220                                                  bd_ail_st_list) {
 221                         bh = bd->bd_bh;
 222
 223                         gfs2_assert(sdp, bd->bd_ail == ai);
 224
 225                         if (!buffer_busy(bh)) {
 226                                 if (!buffer_uptodate(bh)) {
 227                                         gfs2_log_unlock(sdp);
 228                                         gfs2_io_error_bh(sdp, bh);
 229                                         gfs2_log_lock(sdp);
 230                                 }
 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         bd->bd_bh = bh;
 568         bd->bd_gl = gl;
 569
 570         INIT_LIST_HEAD(&bd->bd_list_tr);
 571         if (meta) {
 572                 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
 573         } else {
 574                 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
 575                 get_bh(bh);
 576         }
 577         bh->b_private = bd;
 578
 579         if (meta)
 580                 unlock_page(bh->b_page);
 581 }
 582
 583 /**
 584  * gfs2_pin - Pin a buffer in memory
 585  * @sdp: the filesystem the buffer belongs to
 586  * @bh: The buffer to be pinned
 587  *
 588  */
 589
 590 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
 591 {
 592         struct gfs2_bufdata *bd = bh->b_private;
 593
 594         gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
 595
 596         if (test_set_buffer_pinned(bh))
 597                 gfs2_assert_withdraw(sdp, 0);
 598
 599         wait_on_buffer(bh);
 600
 601         /* If this buffer is in the AIL and it has already been written
 602            to in-place disk block, remove it from the AIL. */
 603
 604         gfs2_log_lock(sdp);
 605         if (bd->bd_ail && !buffer_in_io(bh))
 606                 list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
 607         gfs2_log_unlock(sdp);
 608
 609         clear_buffer_dirty(bh);
 610         wait_on_buffer(bh);
 611
 612         if (!buffer_uptodate(bh))
 613                 gfs2_io_error_bh(sdp, bh);
 614
 615         get_bh(bh);
 616 }
 617
 618 /**
 619  * gfs2_unpin - Unpin a buffer
 620  * @sdp: the filesystem the buffer belongs to
 621  * @bh: The buffer to unpin
 622  * @ai:
 623  *
 624  */
 625
 626 void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
 627                 struct gfs2_ail *ai)
 628 {
 629         struct gfs2_bufdata *bd = bh->b_private;
 630
 631         gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
 632
 633         if (!buffer_pinned(bh))
 634                 gfs2_assert_withdraw(sdp, 0);
 635
 636         mark_buffer_dirty(bh);
 637         clear_buffer_pinned(bh);
 638
 639         gfs2_log_lock(sdp);
 640         if (bd->bd_ail) {
 641                 list_del(&bd->bd_ail_st_list);
 642                 brelse(bh);
 643         } else {
 644                 struct gfs2_glock *gl = bd->bd_gl;
 645                 list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
 646                 atomic_inc(&gl->gl_ail_count);
 647         }
 648         bd->bd_ail = ai;
 649         list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 650         gfs2_log_unlock(sdp);
 651 }
 652
 653 /**
 654  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 655  * @ip: the inode who owns the buffers
 656  * @bstart: the first buffer in the run
 657  * @blen: the number of buffers in the run
 658  *
 659  */
 660
 661 void gfs2_meta_wipe(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
 662 {
 663         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 664         struct inode *aspace = ip->i_gl->gl_aspace;
 665         struct buffer_head *bh;
 666
 667         while (blen) {
 668                 bh = getbuf(sdp, aspace, bstart, NO_CREATE);
 669                 if (bh) {
 670                         struct gfs2_bufdata *bd = bh->b_private;
 671
 672                         if (test_clear_buffer_pinned(bh)) {
 673                                 struct gfs2_trans *tr = current->journal_info;
 674                                 gfs2_log_lock(sdp);
 675                                 list_del_init(&bd->bd_le.le_list);
 676                                 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
 677                                 sdp->sd_log_num_buf--;
 678                                 gfs2_log_unlock(sdp);
 679                                 tr->tr_num_buf_rm++;
 680                                 brelse(bh);
 681                         }
 682                         if (bd) {
 683                                 gfs2_log_lock(sdp);
 684                                 if (bd->bd_ail) {
 685                                         uint64_t blkno = bh->b_blocknr;
 686                                         bd->bd_ail = NULL;
 687                                         list_del(&bd->bd_ail_st_list);
 688                                         list_del(&bd->bd_ail_gl_list);
 689                                         atomic_dec(&bd->bd_gl->gl_ail_count);
 690                                         brelse(bh);
 691                                         gfs2_log_unlock(sdp);
 692                                         gfs2_trans_add_revoke(sdp, blkno);
 693                                 } else
 694                                         gfs2_log_unlock(sdp);
 695                         }
 696
 697                         lock_buffer(bh);
 698                         clear_buffer_dirty(bh);
 699                         clear_buffer_uptodate(bh);
 700                         unlock_buffer(bh);
 701
 702                         brelse(bh);
 703                 }
 704
 705                 bstart++;
 706                 blen--;
 707         }
 708 }
 709
 710 /**
 711  * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
 712  * @ip: The GFS2 inode
 713  *
 714  * This releases buffers that are in the most-recently-used array of
 715  * blocks used for indirect block addressing for this inode.
 716  */
 717
 718 void gfs2_meta_cache_flush(struct gfs2_inode *ip)
 719 {
 720         struct buffer_head **bh_slot;
 721         unsigned int x;
 722
 723         spin_lock(&ip->i_spin);
 724
 725         for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
 726                 bh_slot = &ip->i_cache[x];
 727                 if (!*bh_slot)
 728                         break;
 729                 brelse(*bh_slot);
 730                 *bh_slot = NULL;
 731         }
 732
 733         spin_unlock(&ip->i_spin);
 734 }
 735
 736 /**
 737  * gfs2_meta_indirect_buffer - Get a metadata buffer
 738  * @ip: The GFS2 inode
 739  * @height: The level of this buf in the metadata (indir addr) tree (if any)
 740  * @num: The block number (device relative) of the buffer
 741  * @new: Non-zero if we may create a new buffer
 742  * @bhp: the buffer is returned here
 743  *
 744  * Try to use the gfs2_inode's MRU metadata tree cache.
 745  *
 746  * Returns: errno
 747  */
 748
 749 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, uint64_t num,
 750                               int new, struct buffer_head **bhp)
 751 {
 752         struct buffer_head *bh, **bh_slot = ip->i_cache + height;
 753         int error;
 754
 755         spin_lock(&ip->i_spin);
 756         bh = *bh_slot;
 757         if (bh) {
 758                 if (bh->b_blocknr == num)
 759                         get_bh(bh);
 760                 else
 761                         bh = NULL;
 762         }
 763         spin_unlock(&ip->i_spin);
 764
 765         if (bh) {
 766                 if (new)
 767                         meta_prep_new(bh);
 768                 else {
 769                         error = gfs2_meta_reread(GFS2_SB(&ip->i_inode), bh,
 770                                                  DIO_START | DIO_WAIT);
 771                         if (error) {
 772                                 brelse(bh);
 773                                 return error;
 774                         }
 775                 }
 776         } else {
 777                 if (new)
 778                         bh = gfs2_meta_new(ip->i_gl, num);
 779                 else {
 780                         error = gfs2_meta_read(ip->i_gl, num,
 781                                                DIO_START | DIO_WAIT, &bh);
 782                         if (error)
 783                                 return error;
 784                 }
 785
 786                 spin_lock(&ip->i_spin);
 787                 if (*bh_slot != bh) {
 788                         brelse(*bh_slot);
 789                         *bh_slot = bh;
 790                         get_bh(bh);
 791                 }
 792                 spin_unlock(&ip->i_spin);
 793         }
 794
 795         if (new) {
 796                 if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), height)) {
 797                         brelse(bh);
 798                         return -EIO;
 799                 }
 800                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 801                 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
 802                 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 803
 804         } else if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh,
 805                              (height) ? GFS2_METATYPE_IN : GFS2_METATYPE_DI)) {
 806                 brelse(bh);
 807                 return -EIO;
 808         }
 809
 810         *bhp = bh;
 811
 812         return 0;
 813 }
 814
 815 /**
 816  * gfs2_meta_ra - start readahead on an extent of a file
 817  * @gl: the glock the blocks belong to
 818  * @dblock: the starting disk block
 819  * @extlen: the number of blocks in the extent
 820  *
 821  */
 822
 823 void gfs2_meta_ra(struct gfs2_glock *gl, uint64_t dblock, uint32_t extlen)
 824 {
 825         struct gfs2_sbd *sdp = gl->gl_sbd;
 826         struct inode *aspace = gl->gl_aspace;
 827         struct buffer_head *first_bh, *bh;
 828         uint32_t max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 829                           sdp->sd_sb.sb_bsize_shift;
 830         int error;
 831
 832         if (!extlen || !max_ra)
 833                 return;
 834         if (extlen > max_ra)
 835                 extlen = max_ra;
 836
 837         first_bh = getbuf(sdp, aspace, dblock, CREATE);
 838
 839         if (buffer_uptodate(first_bh))
 840                 goto out;
 841         if (!buffer_locked(first_bh)) {
 842                 error = gfs2_meta_reread(sdp, first_bh, DIO_START);
 843                 if (error)
 844                         goto out;
 845         }
 846
 847         dblock++;
 848         extlen--;
 849
 850         while (extlen) {
 851                 bh = getbuf(sdp, aspace, dblock, CREATE);
 852
 853                 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
 854                         error = gfs2_meta_reread(sdp, bh, DIO_START);
 855                         brelse(bh);
 856                         if (error)
 857                                 goto out;
 858                 } else
 859                         brelse(bh);
 860
 861                 dblock++;
 862                 extlen--;
 863
 864                 if (buffer_uptodate(first_bh))
 865                         break;
 866         }
 867
 868  out:
 869         brelse(first_bh);
 870 }
 871
 872 /**
 873  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 874  * @sdp: the filesystem
 875  *
 876  */
 877
 878 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 879 {
 880         gfs2_log_flush(sdp, NULL);
 881         for (;;) {
 882                 gfs2_ail1_start(sdp, DIO_ALL);
 883                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 884                         break;
 885                 msleep(10);
 886         }
 887 }
 888