SAFE public projects git trees. - safe/jmp/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_log_unlock(sdp);
 231                                         gfs2_io_error_bh(sdp, bh);
 232                                         gfs2_log_lock(sdp);
 233                                 }
 234                                 list_move(&bd->bd_ail_st_list,
 235                                           &ai->ai_ail2_list);
 236                                 continue;
 237                         }
 238
 239                         if (!buffer_dirty(bh))
 240                                 continue;
 241
 242                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 243
 244                         gfs2_log_unlock(sdp);
 245                         wait_on_buffer(bh);
 246                         ll_rw_block(WRITE, 1, &bh);
 247                         gfs2_log_lock(sdp);
 248
 249                         retry = 1;
 250                         break;
 251                 }
 252         } while (retry);
 253 }
 254
 255 /**
 256  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 257  * @sdp: the filesystem
 258  * @ai: the AIL entry
 259  *
 260  */
 261
 262 int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 263 {
 264         struct gfs2_bufdata *bd, *s;
 265         struct buffer_head *bh;
 266
 267         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 268                                          bd_ail_st_list) {
 269                 bh = bd->bd_bh;
 270
 271                 gfs2_assert(sdp, bd->bd_ail == ai);
 272
 273                 if (buffer_busy(bh)) {
 274                         if (flags & DIO_ALL)
 275                                 continue;
 276                         else
 277                                 break;
 278                 }
 279
 280                 if (!buffer_uptodate(bh))
 281                         gfs2_io_error_bh(sdp, bh);
 282
 283                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 284         }
 285
 286         return list_empty(&ai->ai_ail1_list);
 287 }
 288
 289 /**
 290  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 291  * @sdp: the filesystem
 292  * @ai: the AIL entry
 293  *
 294  */
 295
 296 void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 297 {
 298         struct list_head *head = &ai->ai_ail2_list;
 299         struct gfs2_bufdata *bd;
 300
 301         while (!list_empty(head)) {
 302                 bd = list_entry(head->prev, struct gfs2_bufdata,
 303                                 bd_ail_st_list);
 304                 gfs2_assert(sdp, bd->bd_ail == ai);
 305                 bd->bd_ail = NULL;
 306                 list_del(&bd->bd_ail_st_list);
 307                 list_del(&bd->bd_ail_gl_list);
 308                 atomic_dec(&bd->bd_gl->gl_ail_count);
 309                 brelse(bd->bd_bh);
 310         }
 311 }
 312
 313 /**
 314  * ail_empty_gl - remove all buffers for a given lock from the AIL
 315  * @gl: the glock
 316  *
 317  * None of the buffers should be dirty, locked, or pinned.
 318  */
 319
 320 void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 321 {
 322         struct gfs2_sbd *sdp = gl->gl_sbd;
 323         unsigned int blocks;
 324         struct list_head *head = &gl->gl_ail_list;
 325         struct gfs2_bufdata *bd;
 326         struct buffer_head *bh;
 327         uint64_t blkno;
 328         int error;
 329
 330         blocks = atomic_read(&gl->gl_ail_count);
 331         if (!blocks)
 332                 return;
 333
 334         error = gfs2_trans_begin(sdp, 0, blocks);
 335         if (gfs2_assert_withdraw(sdp, !error))
 336                 return;
 337
 338         gfs2_log_lock(sdp);
 339         while (!list_empty(head)) {
 340                 bd = list_entry(head->next, struct gfs2_bufdata,
 341                                 bd_ail_gl_list);
 342                 bh = bd->bd_bh;
 343                 blkno = bh->b_blocknr;
 344                 gfs2_assert_withdraw(sdp, !buffer_busy(bh));
 345
 346                 bd->bd_ail = NULL;
 347                 list_del(&bd->bd_ail_st_list);
 348                 list_del(&bd->bd_ail_gl_list);
 349                 atomic_dec(&gl->gl_ail_count);
 350                 brelse(bh);
 351                 gfs2_log_unlock(sdp);
 352
 353                 gfs2_trans_add_revoke(sdp, blkno);
 354
 355                 gfs2_log_lock(sdp);
 356         }
 357         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 358         gfs2_log_unlock(sdp);
 359
 360         gfs2_trans_end(sdp);
 361         gfs2_log_flush(sdp, NULL);
 362 }
 363
 364 /**
 365  * gfs2_meta_inval - Invalidate all buffers associated with a glock
 366  * @gl: the glock
 367  *
 368  */
 369
 370 void gfs2_meta_inval(struct gfs2_glock *gl)
 371 {
 372         struct gfs2_sbd *sdp = gl->gl_sbd;
 373         struct inode *aspace = gl->gl_aspace;
 374         struct address_space *mapping = gl->gl_aspace->i_mapping;
 375
 376         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 377
 378         atomic_inc(&aspace->i_writecount);
 379         truncate_inode_pages(mapping, 0);
 380         atomic_dec(&aspace->i_writecount);
 381
 382         gfs2_assert_withdraw(sdp, !mapping->nrpages);
 383 }
 384
 385 /**
 386  * gfs2_meta_sync - Sync all buffers associated with a glock
 387  * @gl: The glock
 388  * @flags: DIO_START | DIO_WAIT
 389  *
 390  */
 391
 392 void gfs2_meta_sync(struct gfs2_glock *gl, int flags)
 393 {
 394         struct address_space *mapping = gl->gl_aspace->i_mapping;
 395         int error = 0;
 396
 397         if (flags & DIO_START)
 398                 filemap_fdatawrite(mapping);
 399         if (!error && (flags & DIO_WAIT))
 400                 error = filemap_fdatawait(mapping);
 401
 402         if (error)
 403                 gfs2_io_error(gl->gl_sbd);
 404 }
 405
 406 /**
 407  * getbuf - Get a buffer with a given address space
 408  * @sdp: the filesystem
 409  * @aspace: the address space
 410  * @blkno: the block number (filesystem scope)
 411  * @create: 1 if the buffer should be created
 412  *
 413  * Returns: the buffer
 414  */
 415
 416 static struct buffer_head *getbuf(struct gfs2_sbd *sdp, struct inode *aspace,
 417                                   uint64_t blkno, int create)
 418 {
 419         struct page *page;
 420         struct buffer_head *bh;
 421         unsigned int shift;
 422         unsigned long index;
 423         unsigned int bufnum;
 424
 425         shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 426         index = blkno >> shift;             /* convert block to page */
 427         bufnum = blkno - (index << shift);  /* block buf index within page */
 428
 429         if (create) {
 430                 for (;;) {
 431                         page = grab_cache_page(aspace->i_mapping, index);
 432                         if (page)
 433                                 break;
 434                         yield();
 435                 }
 436         } else {
 437                 page = find_lock_page(aspace->i_mapping, index);
 438                 if (!page)
 439                         return NULL;
 440         }
 441
 442         if (!page_has_buffers(page))
 443                 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 444
 445         /* Locate header for our buffer within our page */
 446         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 447                 /* Do nothing */;
 448         get_bh(bh);
 449
 450         if (!buffer_mapped(bh))
 451                 map_bh(bh, sdp->sd_vfs, blkno);
 452
 453         unlock_page(page);
 454         mark_page_accessed(page);
 455         page_cache_release(page);
 456
 457         return bh;
 458 }
 459
 460 static void meta_prep_new(struct buffer_head *bh)
 461 {
 462         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 463
 464         lock_buffer(bh);
 465         clear_buffer_dirty(bh);
 466         set_buffer_uptodate(bh);
 467         unlock_buffer(bh);
 468
 469         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 470 }
 471
 472 /**
 473  * gfs2_meta_new - Get a block
 474  * @gl: The glock associated with this block
 475  * @blkno: The block number
 476  *
 477  * Returns: The buffer
 478  */
 479
 480 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, uint64_t blkno)
 481 {
 482         struct buffer_head *bh;
 483         bh = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 484         meta_prep_new(bh);
 485         return bh;
 486 }
 487
 488 /**
 489  * gfs2_meta_read - Read a block from disk
 490  * @gl: The glock covering the block
 491  * @blkno: The block number
 492  * @flags: flags to gfs2_dreread()
 493  * @bhp: the place where the buffer is returned (NULL on failure)
 494  *
 495  * Returns: errno
 496  */
 497
 498 int gfs2_meta_read(struct gfs2_glock *gl, uint64_t blkno, int flags,
 499                    struct buffer_head **bhp)
 500 {
 501         int error;
 502
 503         *bhp = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 504         error = gfs2_meta_reread(gl->gl_sbd, *bhp, flags);
 505         if (error)
 506                 brelse(*bhp);
 507
 508         return error;
 509 }
 510
 511 /**
 512  * gfs2_meta_reread - Reread a block from disk
 513  * @sdp: the filesystem
 514  * @bh: The block to read
 515  * @flags: Flags that control the read
 516  *
 517  * Returns: errno
 518  */
 519
 520 int gfs2_meta_reread(struct gfs2_sbd *sdp, struct buffer_head *bh, int flags)
 521 {
 522         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 523                 return -EIO;
 524
 525         if (flags & DIO_FORCE)
 526                 clear_buffer_uptodate(bh);
 527
 528         if ((flags & DIO_START) && !buffer_uptodate(bh))
 529                 ll_rw_block(READ, 1, &bh);
 530
 531         if (flags & DIO_WAIT) {
 532                 wait_on_buffer(bh);
 533
 534                 if (!buffer_uptodate(bh)) {
 535                         struct gfs2_trans *tr = current->journal_info;
 536                         if (tr && tr->tr_touched)
 537                                 gfs2_io_error_bh(sdp, bh);
 538                         return -EIO;
 539                 }
 540                 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 541                         return -EIO;
 542         }
 543
 544         return 0;
 545 }
 546
 547 /**
 548  * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
 549  * @gl: the glock the buffer belongs to
 550  * @bh: The buffer to be attached to
 551  * @meta: Flag to indicate whether its metadata or not
 552  */
 553
 554 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
 555                          int meta)
 556 {
 557         struct gfs2_bufdata *bd;
 558
 559         if (meta)
 560                 lock_page(bh->b_page);
 561
 562         if (bh->b_private) {
 563                 if (meta)
 564                         unlock_page(bh->b_page);
 565                 return;
 566         }
 567
 568         bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
 569         memset(bd, 0, sizeof(struct gfs2_bufdata));
 570
 571         bd->bd_bh = bh;
 572         bd->bd_gl = gl;
 573
 574         INIT_LIST_HEAD(&bd->bd_list_tr);
 575         if (meta) {
 576                 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
 577         } else {
 578                 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
 579                 get_bh(bh);
 580         }
 581         bh->b_private = bd;
 582
 583         if (meta)
 584                 unlock_page(bh->b_page);
 585 }
 586
 587 /**
 588  * gfs2_pin - Pin a buffer in memory
 589  * @sdp: the filesystem the buffer belongs to
 590  * @bh: The buffer to be pinned
 591  *
 592  */
 593
 594 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
 595 {
 596         struct gfs2_bufdata *bd = bh->b_private;
 597
 598         gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
 599
 600         if (test_set_buffer_pinned(bh))
 601                 gfs2_assert_withdraw(sdp, 0);
 602
 603         wait_on_buffer(bh);
 604
 605         /* If this buffer is in the AIL and it has already been written
 606            to in-place disk block, remove it from the AIL. */
 607
 608         gfs2_log_lock(sdp);
 609         if (bd->bd_ail && !buffer_in_io(bh))
 610                 list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
 611         gfs2_log_unlock(sdp);
 612
 613         clear_buffer_dirty(bh);
 614         wait_on_buffer(bh);
 615
 616         if (!buffer_uptodate(bh))
 617                 gfs2_io_error_bh(sdp, bh);
 618
 619         get_bh(bh);
 620 }
 621
 622 /**
 623  * gfs2_unpin - Unpin a buffer
 624  * @sdp: the filesystem the buffer belongs to
 625  * @bh: The buffer to unpin
 626  * @ai:
 627  *
 628  */
 629
 630 void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
 631                 struct gfs2_ail *ai)
 632 {
 633         struct gfs2_bufdata *bd = bh->b_private;
 634
 635         gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
 636
 637         if (!buffer_pinned(bh))
 638                 gfs2_assert_withdraw(sdp, 0);
 639
 640         mark_buffer_dirty(bh);
 641         clear_buffer_pinned(bh);
 642
 643         gfs2_log_lock(sdp);
 644         if (bd->bd_ail) {
 645                 list_del(&bd->bd_ail_st_list);
 646                 brelse(bh);
 647         } else {
 648                 struct gfs2_glock *gl = bd->bd_gl;
 649                 list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
 650                 atomic_inc(&gl->gl_ail_count);
 651         }
 652         bd->bd_ail = ai;
 653         list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 654         gfs2_log_unlock(sdp);
 655 }
 656
 657 /**
 658  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 659  * @ip: the inode who owns the buffers
 660  * @bstart: the first buffer in the run
 661  * @blen: the number of buffers in the run
 662  *
 663  */
 664
 665 void gfs2_meta_wipe(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
 666 {
 667         struct gfs2_sbd *sdp = ip->i_sbd;
 668         struct inode *aspace = ip->i_gl->gl_aspace;
 669         struct buffer_head *bh;
 670
 671         while (blen) {
 672                 bh = getbuf(sdp, aspace, bstart, NO_CREATE);
 673                 if (bh) {
 674                         struct gfs2_bufdata *bd = bh->b_private;
 675
 676                         if (test_clear_buffer_pinned(bh)) {
 677                                 struct gfs2_trans *tr = current->journal_info;
 678                                 gfs2_log_lock(sdp);
 679                                 list_del_init(&bd->bd_le.le_list);
 680                                 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
 681                                 sdp->sd_log_num_buf--;
 682                                 gfs2_log_unlock(sdp);
 683                                 tr->tr_num_buf_rm++;
 684                                 brelse(bh);
 685                         }
 686                         if (bd) {
 687                                 gfs2_log_lock(sdp);
 688                                 if (bd->bd_ail) {
 689                                         uint64_t blkno = bh->b_blocknr;
 690                                         bd->bd_ail = NULL;
 691                                         list_del(&bd->bd_ail_st_list);
 692                                         list_del(&bd->bd_ail_gl_list);
 693                                         atomic_dec(&bd->bd_gl->gl_ail_count);
 694                                         brelse(bh);
 695                                         gfs2_log_unlock(sdp);
 696                                         gfs2_trans_add_revoke(sdp, blkno);
 697                                 } else
 698                                         gfs2_log_unlock(sdp);
 699                         }
 700
 701                         lock_buffer(bh);
 702                         clear_buffer_dirty(bh);
 703                         clear_buffer_uptodate(bh);
 704                         unlock_buffer(bh);
 705
 706                         brelse(bh);
 707                 }
 708
 709                 bstart++;
 710                 blen--;
 711         }
 712 }
 713
 714 /**
 715  * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
 716  * @ip: The GFS2 inode
 717  *
 718  * This releases buffers that are in the most-recently-used array of
 719  * blocks used for indirect block addressing for this inode.
 720  */
 721
 722 void gfs2_meta_cache_flush(struct gfs2_inode *ip)
 723 {
 724         struct buffer_head **bh_slot;
 725         unsigned int x;
 726
 727         spin_lock(&ip->i_spin);
 728
 729         for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
 730                 bh_slot = &ip->i_cache[x];
 731                 if (!*bh_slot)
 732                         break;
 733                 brelse(*bh_slot);
 734                 *bh_slot = NULL;
 735         }
 736
 737         spin_unlock(&ip->i_spin);
 738 }
 739
 740 /**
 741  * gfs2_meta_indirect_buffer - Get a metadata buffer
 742  * @ip: The GFS2 inode
 743  * @height: The level of this buf in the metadata (indir addr) tree (if any)
 744  * @num: The block number (device relative) of the buffer
 745  * @new: Non-zero if we may create a new buffer
 746  * @bhp: the buffer is returned here
 747  *
 748  * Try to use the gfs2_inode's MRU metadata tree cache.
 749  *
 750  * Returns: errno
 751  */
 752
 753 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, uint64_t num,
 754                               int new, struct buffer_head **bhp)
 755 {
 756         struct buffer_head *bh, **bh_slot = ip->i_cache + height;
 757         int error;
 758
 759         spin_lock(&ip->i_spin);
 760         bh = *bh_slot;
 761         if (bh) {
 762                 if (bh->b_blocknr == num)
 763                         get_bh(bh);
 764                 else
 765                         bh = NULL;
 766         }
 767         spin_unlock(&ip->i_spin);
 768
 769         if (bh) {
 770                 if (new)
 771                         meta_prep_new(bh);
 772                 else {
 773                         error = gfs2_meta_reread(ip->i_sbd, bh,
 774                                                  DIO_START | DIO_WAIT);
 775                         if (error) {
 776                                 brelse(bh);
 777                                 return error;
 778                         }
 779                 }
 780         } else {
 781                 if (new)
 782                         bh = gfs2_meta_new(ip->i_gl, num);
 783                 else {
 784                         error = gfs2_meta_read(ip->i_gl, num,
 785                                                DIO_START | DIO_WAIT, &bh);
 786                         if (error)
 787                                 return error;
 788                 }
 789
 790                 spin_lock(&ip->i_spin);
 791                 if (*bh_slot != bh) {
 792                         brelse(*bh_slot);
 793                         *bh_slot = bh;
 794                         get_bh(bh);
 795                 }
 796                 spin_unlock(&ip->i_spin);
 797         }
 798
 799         if (new) {
 800                 if (gfs2_assert_warn(ip->i_sbd, height)) {
 801                         brelse(bh);
 802                         return -EIO;
 803                 }
 804                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 805                 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
 806                 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 807
 808         } else if (gfs2_metatype_check(ip->i_sbd, bh,
 809                              (height) ? GFS2_METATYPE_IN : GFS2_METATYPE_DI)) {
 810                 brelse(bh);
 811                 return -EIO;
 812         }
 813
 814         *bhp = bh;
 815
 816         return 0;
 817 }
 818
 819 /**
 820  * gfs2_meta_ra - start readahead on an extent of a file
 821  * @gl: the glock the blocks belong to
 822  * @dblock: the starting disk block
 823  * @extlen: the number of blocks in the extent
 824  *
 825  */
 826
 827 void gfs2_meta_ra(struct gfs2_glock *gl, uint64_t dblock, uint32_t extlen)
 828 {
 829         struct gfs2_sbd *sdp = gl->gl_sbd;
 830         struct inode *aspace = gl->gl_aspace;
 831         struct buffer_head *first_bh, *bh;
 832         uint32_t max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 833                           sdp->sd_sb.sb_bsize_shift;
 834         int error;
 835
 836         if (!extlen || !max_ra)
 837                 return;
 838         if (extlen > max_ra)
 839                 extlen = max_ra;
 840
 841         first_bh = getbuf(sdp, aspace, dblock, CREATE);
 842
 843         if (buffer_uptodate(first_bh))
 844                 goto out;
 845         if (!buffer_locked(first_bh)) {
 846                 error = gfs2_meta_reread(sdp, first_bh, DIO_START);
 847                 if (error)
 848                         goto out;
 849         }
 850
 851         dblock++;
 852         extlen--;
 853
 854         while (extlen) {
 855                 bh = getbuf(sdp, aspace, dblock, CREATE);
 856
 857                 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
 858                         error = gfs2_meta_reread(sdp, bh, DIO_START);
 859                         brelse(bh);
 860                         if (error)
 861                                 goto out;
 862                 } else
 863                         brelse(bh);
 864
 865                 dblock++;
 866                 extlen--;
 867
 868                 if (buffer_uptodate(first_bh))
 869                         break;
 870         }
 871
 872  out:
 873         brelse(first_bh);
 874 }
 875
 876 /**
 877  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 878  * @sdp: the filesystem
 879  *
 880  */
 881
 882 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 883 {
 884         gfs2_log_flush(sdp, NULL);
 885         for (;;) {
 886                 gfs2_ail1_start(sdp, DIO_ALL);
 887                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 888                         break;
 889                 msleep(10);
 890         }
 891 }
 892