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) 2004-2006 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                 (uint64_t)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, 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                         ip->i_num.no_formal_ino, ip->i_num.no_addr);
  93                 fs_warn(sdp, "ip->i_count = %d, ip->i_vnode = %s\n",
  94                         atomic_read(&ip->i_count),
  95                         (ip->i_vnode) ? "!NULL" : "NULL");
  96
  97                 for (x = 0; x < GFS2_MAX_META_HEIGHT; x++)
  98                         fs_warn(sdp, "ip->i_cache[%u] = %s\n",
  99                                 x, (ip->i_cache[x]) ? "!NULL" : "NULL");
 100         }
 101 }
 102
 103 /**
 104  * gfs2_aspace_releasepage - free the metadata associated with a page
 105  * @page: the page that's being released
 106  * @gfp_mask: passed from Linux VFS, ignored by us
 107  *
 108  * Call try_to_free_buffers() if the buffers in this page can be
 109  * released.
 110  *
 111  * Returns: 0
 112  */
 113
 114 static int gfs2_aspace_releasepage(struct page *page, gfp_t gfp_mask)
 115 {
 116         struct inode *aspace = page->mapping->host;
 117         struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
 118         struct buffer_head *bh, *head;
 119         struct gfs2_bufdata *bd;
 120         unsigned long t;
 121
 122         if (!page_has_buffers(page))
 123                 goto out;
 124
 125         head = bh = page_buffers(page);
 126         do {
 127                 t = jiffies;
 128
 129                 while (atomic_read(&bh->b_count)) {
 130                         if (atomic_read(&aspace->i_writecount)) {
 131                                 if (time_after_eq(jiffies, t +
 132                                     gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
 133                                         stuck_releasepage(bh);
 134                                         t = jiffies;
 135                                 }
 136
 137                                 yield();
 138                                 continue;
 139                         }
 140
 141                         return 0;
 142                 }
 143
 144                 gfs2_assert_warn(sdp, !buffer_pinned(bh));
 145
 146                 bd = bh->b_private;
 147                 if (bd) {
 148                         gfs2_assert_warn(sdp, bd->bd_bh == bh);
 149                         gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
 150                         gfs2_assert_warn(sdp, list_empty(&bd->bd_le.le_list));
 151                         gfs2_assert_warn(sdp, !bd->bd_ail);
 152                         kmem_cache_free(gfs2_bufdata_cachep, bd);
 153                         bh->b_private = NULL;
 154                 }
 155
 156                 bh = bh->b_this_page;
 157         }
 158         while (bh != head);
 159
 160  out:
 161         return try_to_free_buffers(page);
 162 }
 163
 164 static struct address_space_operations aspace_aops = {
 165         .writepage = gfs2_aspace_writepage,
 166         .releasepage = gfs2_aspace_releasepage,
 167 };
 168
 169 /**
 170  * gfs2_aspace_get - Create and initialize a struct inode structure
 171  * @sdp: the filesystem the aspace is in
 172  *
 173  * Right now a struct inode is just a struct inode.  Maybe Linux
 174  * will supply a more lightweight address space construct (that works)
 175  * in the future.
 176  *
 177  * Make sure pages/buffers in this aspace aren't in high memory.
 178  *
 179  * Returns: the aspace
 180  */
 181
 182 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
 183 {
 184         struct inode *aspace;
 185
 186         aspace = new_inode(sdp->sd_vfs);
 187         if (aspace) {
 188                 mapping_set_gfp_mask(aspace->i_mapping, GFP_KERNEL);
 189                 aspace->i_mapping->a_ops = &aspace_aops;
 190                 aspace->i_size = ~0ULL;
 191                 aspace->u.generic_ip = NULL;
 192                 insert_inode_hash(aspace);
 193         }
 194         return aspace;
 195 }
 196
 197 void gfs2_aspace_put(struct inode *aspace)
 198 {
 199         remove_inode_hash(aspace);
 200         iput(aspace);
 201 }
 202
 203 /**
 204  * gfs2_ail1_start_one - Start I/O on a part of the AIL
 205  * @sdp: the filesystem
 206  * @tr: the part of the AIL
 207  *
 208  */
 209
 210 void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 211 {
 212         struct gfs2_bufdata *bd, *s;
 213         struct buffer_head *bh;
 214         int retry;
 215
 216         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
 217
 218         do {
 219                 retry = 0;
 220
 221                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 222                                                  bd_ail_st_list) {
 223                         bh = bd->bd_bh;
 224
 225                         gfs2_assert(sdp, bd->bd_ail == ai);
 226
 227                         if (!buffer_busy(bh)) {
 228                                 if (!buffer_uptodate(bh)) {
 229                                         gfs2_log_unlock(sdp);
 230                                         gfs2_io_error_bh(sdp, bh);
 231                                         gfs2_log_lock(sdp);
 232                                 }
 233                                 list_move(&bd->bd_ail_st_list,
 234                                           &ai->ai_ail2_list);
 235                                 continue;
 236                         }
 237
 238                         if (!buffer_dirty(bh))
 239                                 continue;
 240
 241                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 242
 243                         gfs2_log_unlock(sdp);
 244                         wait_on_buffer(bh);
 245                         ll_rw_block(WRITE, 1, &bh);
 246                         gfs2_log_lock(sdp);
 247
 248                         retry = 1;
 249                         break;
 250                 }
 251         } while (retry);
 252 }
 253
 254 /**
 255  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 256  * @sdp: the filesystem
 257  * @ai: the AIL entry
 258  *
 259  */
 260
 261 int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 262 {
 263         struct gfs2_bufdata *bd, *s;
 264         struct buffer_head *bh;
 265
 266         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 267                                          bd_ail_st_list) {
 268                 bh = bd->bd_bh;
 269
 270                 gfs2_assert(sdp, bd->bd_ail == ai);
 271
 272                 if (buffer_busy(bh)) {
 273                         if (flags & DIO_ALL)
 274                                 continue;
 275                         else
 276                                 break;
 277                 }
 278
 279                 if (!buffer_uptodate(bh))
 280                         gfs2_io_error_bh(sdp, bh);
 281
 282                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 283         }
 284
 285         return list_empty(&ai->ai_ail1_list);
 286 }
 287
 288 /**
 289  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 290  * @sdp: the filesystem
 291  * @ai: the AIL entry
 292  *
 293  */
 294
 295 void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 296 {
 297         struct list_head *head = &ai->ai_ail2_list;
 298         struct gfs2_bufdata *bd;
 299
 300         while (!list_empty(head)) {
 301                 bd = list_entry(head->prev, struct gfs2_bufdata,
 302                                 bd_ail_st_list);
 303                 gfs2_assert(sdp, bd->bd_ail == ai);
 304                 bd->bd_ail = NULL;
 305                 list_del(&bd->bd_ail_st_list);
 306                 list_del(&bd->bd_ail_gl_list);
 307                 atomic_dec(&bd->bd_gl->gl_ail_count);
 308                 brelse(bd->bd_bh);
 309         }
 310 }
 311
 312 /**
 313  * ail_empty_gl - remove all buffers for a given lock from the AIL
 314  * @gl: the glock
 315  *
 316  * None of the buffers should be dirty, locked, or pinned.
 317  */
 318
 319 void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 320 {
 321         struct gfs2_sbd *sdp = gl->gl_sbd;
 322         unsigned int blocks;
 323         struct list_head *head = &gl->gl_ail_list;
 324         struct gfs2_bufdata *bd;
 325         struct buffer_head *bh;
 326         uint64_t blkno;
 327         int error;
 328
 329         blocks = atomic_read(&gl->gl_ail_count);
 330         if (!blocks)
 331                 return;
 332
 333         error = gfs2_trans_begin(sdp, 0, blocks);
 334         if (gfs2_assert_withdraw(sdp, !error))
 335                 return;
 336
 337         gfs2_log_lock(sdp);
 338         while (!list_empty(head)) {
 339                 bd = list_entry(head->next, struct gfs2_bufdata,
 340                                 bd_ail_gl_list);
 341                 bh = bd->bd_bh;
 342                 blkno = bh->b_blocknr;
 343                 gfs2_assert_withdraw(sdp, !buffer_busy(bh));
 344
 345                 bd->bd_ail = NULL;
 346                 list_del(&bd->bd_ail_st_list);
 347                 list_del(&bd->bd_ail_gl_list);
 348                 atomic_dec(&gl->gl_ail_count);
 349                 brelse(bh);
 350                 gfs2_log_unlock(sdp);
 351
 352                 gfs2_trans_add_revoke(sdp, blkno);
 353
 354                 gfs2_log_lock(sdp);
 355         }
 356         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 357         gfs2_log_unlock(sdp);
 358
 359         gfs2_trans_end(sdp);
 360         gfs2_log_flush(sdp, NULL);
 361 }
 362
 363 /**
 364  * gfs2_meta_inval - Invalidate all buffers associated with a glock
 365  * @gl: the glock
 366  *
 367  */
 368
 369 void gfs2_meta_inval(struct gfs2_glock *gl)
 370 {
 371         struct gfs2_sbd *sdp = gl->gl_sbd;
 372         struct inode *aspace = gl->gl_aspace;
 373         struct address_space *mapping = gl->gl_aspace->i_mapping;
 374
 375         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 376
 377         atomic_inc(&aspace->i_writecount);
 378         truncate_inode_pages(mapping, 0);
 379         atomic_dec(&aspace->i_writecount);
 380
 381         gfs2_assert_withdraw(sdp, !mapping->nrpages);
 382 }
 383
 384 /**
 385  * gfs2_meta_sync - Sync all buffers associated with a glock
 386  * @gl: The glock
 387  * @flags: DIO_START | DIO_WAIT
 388  *
 389  */
 390
 391 void gfs2_meta_sync(struct gfs2_glock *gl, int flags)
 392 {
 393         struct address_space *mapping = gl->gl_aspace->i_mapping;
 394         int error = 0;
 395
 396         if (flags & DIO_START)
 397                 filemap_fdatawrite(mapping);
 398         if (!error && (flags & DIO_WAIT))
 399                 error = filemap_fdatawait(mapping);
 400
 401         if (error)
 402                 gfs2_io_error(gl->gl_sbd);
 403 }
 404
 405 /**
 406  * getbuf - Get a buffer with a given address space
 407  * @sdp: the filesystem
 408  * @aspace: the address space
 409  * @blkno: the block number (filesystem scope)
 410  * @create: 1 if the buffer should be created
 411  *
 412  * Returns: the buffer
 413  */
 414
 415 static struct buffer_head *getbuf(struct gfs2_sbd *sdp, struct inode *aspace,
 416                                   uint64_t blkno, int create)
 417 {
 418         struct page *page;
 419         struct buffer_head *bh;
 420         unsigned int shift;
 421         unsigned long index;
 422         unsigned int bufnum;
 423
 424         shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 425         index = blkno >> shift;             /* convert block to page */
 426         bufnum = blkno - (index << shift);  /* block buf index within page */
 427
 428         if (create) {
 429                 for (;;) {
 430                         page = grab_cache_page(aspace->i_mapping, index);
 431                         if (page)
 432                                 break;
 433                         yield();
 434                 }
 435         } else {
 436                 page = find_lock_page(aspace->i_mapping, index);
 437                 if (!page)
 438                         return NULL;
 439         }
 440
 441         if (!page_has_buffers(page))
 442                 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 443
 444         /* Locate header for our buffer within our page */
 445         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 446                 /* Do nothing */;
 447         get_bh(bh);
 448
 449         if (!buffer_mapped(bh))
 450                 map_bh(bh, sdp->sd_vfs, blkno);
 451
 452         unlock_page(page);
 453         mark_page_accessed(page);
 454         page_cache_release(page);
 455
 456         return bh;
 457 }
 458
 459 static void meta_prep_new(struct buffer_head *bh)
 460 {
 461         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 462
 463         lock_buffer(bh);
 464         clear_buffer_dirty(bh);
 465         set_buffer_uptodate(bh);
 466         unlock_buffer(bh);
 467
 468         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 469 }
 470
 471 /**
 472  * gfs2_meta_new - Get a block
 473  * @gl: The glock associated with this block
 474  * @blkno: The block number
 475  *
 476  * Returns: The buffer
 477  */
 478
 479 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, uint64_t blkno)
 480 {
 481         struct buffer_head *bh;
 482         bh = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 483         meta_prep_new(bh);
 484         return bh;
 485 }
 486
 487 /**
 488  * gfs2_meta_read - Read a block from disk
 489  * @gl: The glock covering the block
 490  * @blkno: The block number
 491  * @flags: flags to gfs2_dreread()
 492  * @bhp: the place where the buffer is returned (NULL on failure)
 493  *
 494  * Returns: errno
 495  */
 496
 497 int gfs2_meta_read(struct gfs2_glock *gl, uint64_t blkno, int flags,
 498                    struct buffer_head **bhp)
 499 {
 500         int error;
 501
 502         *bhp = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 503         error = gfs2_meta_reread(gl->gl_sbd, *bhp, flags);
 504         if (error)
 505                 brelse(*bhp);
 506
 507         return error;
 508 }
 509
 510 /**
 511  * gfs2_meta_reread - Reread a block from disk
 512  * @sdp: the filesystem
 513  * @bh: The block to read
 514  * @flags: Flags that control the read
 515  *
 516  * Returns: errno
 517  */
 518
 519 int gfs2_meta_reread(struct gfs2_sbd *sdp, struct buffer_head *bh, int flags)
 520 {
 521         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 522                 return -EIO;
 523
 524         if (flags & DIO_FORCE)
 525                 clear_buffer_uptodate(bh);
 526
 527         if ((flags & DIO_START) && !buffer_uptodate(bh))
 528                 ll_rw_block(READ, 1, &bh);
 529
 530         if (flags & DIO_WAIT) {
 531                 wait_on_buffer(bh);
 532
 533                 if (!buffer_uptodate(bh)) {
 534                         struct gfs2_trans *tr = current->journal_info;
 535                         if (tr && tr->tr_touched)
 536                                 gfs2_io_error_bh(sdp, bh);
 537                         return -EIO;
 538                 }
 539                 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 540                         return -EIO;
 541         }
 542
 543         return 0;
 544 }
 545
 546 /**
 547  * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
 548  * @gl: the glock the buffer belongs to
 549  * @bh: The buffer to be attached to
 550  * @meta: Flag to indicate whether its metadata or not
 551  */
 552
 553 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
 554                          int meta)
 555 {
 556         struct gfs2_bufdata *bd;
 557
 558         if (meta)
 559                 lock_page(bh->b_page);
 560
 561         if (bh->b_private) {
 562                 if (meta)
 563                         unlock_page(bh->b_page);
 564                 return;
 565         }
 566
 567         bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
 568         memset(bd, 0, sizeof(struct gfs2_bufdata));
 569
 570         bd->bd_bh = bh;
 571         bd->bd_gl = gl;
 572
 573         INIT_LIST_HEAD(&bd->bd_list_tr);
 574         if (meta) {
 575                 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
 576         } else {
 577                 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
 578                 get_bh(bh);
 579         }
 580         bh->b_private = bd;
 581
 582         if (meta)
 583                 unlock_page(bh->b_page);
 584 }
 585
 586 /**
 587  * gfs2_pin - Pin a buffer in memory
 588  * @sdp: the filesystem the buffer belongs to
 589  * @bh: The buffer to be pinned
 590  *
 591  */
 592
 593 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
 594 {
 595         struct gfs2_bufdata *bd = bh->b_private;
 596
 597         gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
 598
 599         if (test_set_buffer_pinned(bh))
 600                 gfs2_assert_withdraw(sdp, 0);
 601
 602         wait_on_buffer(bh);
 603
 604         /* If this buffer is in the AIL and it has already been written
 605            to in-place disk block, remove it from the AIL. */
 606
 607         gfs2_log_lock(sdp);
 608         if (bd->bd_ail && !buffer_in_io(bh))
 609                 list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
 610         gfs2_log_unlock(sdp);
 611
 612         clear_buffer_dirty(bh);
 613         wait_on_buffer(bh);
 614
 615         if (!buffer_uptodate(bh))
 616                 gfs2_io_error_bh(sdp, bh);
 617
 618         get_bh(bh);
 619 }
 620
 621 /**
 622  * gfs2_unpin - Unpin a buffer
 623  * @sdp: the filesystem the buffer belongs to
 624  * @bh: The buffer to unpin
 625  * @ai:
 626  *
 627  */
 628
 629 void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
 630                 struct gfs2_ail *ai)
 631 {
 632         struct gfs2_bufdata *bd = bh->b_private;
 633
 634         gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
 635
 636         if (!buffer_pinned(bh))
 637                 gfs2_assert_withdraw(sdp, 0);
 638
 639         mark_buffer_dirty(bh);
 640         clear_buffer_pinned(bh);
 641
 642         gfs2_log_lock(sdp);
 643         if (bd->bd_ail) {
 644                 list_del(&bd->bd_ail_st_list);
 645                 brelse(bh);
 646         } else {
 647                 struct gfs2_glock *gl = bd->bd_gl;
 648                 list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
 649                 atomic_inc(&gl->gl_ail_count);
 650         }
 651         bd->bd_ail = ai;
 652         list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 653         gfs2_log_unlock(sdp);
 654 }
 655
 656 /**
 657  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 658  * @ip: the inode who owns the buffers
 659  * @bstart: the first buffer in the run
 660  * @blen: the number of buffers in the run
 661  *
 662  */
 663
 664 void gfs2_meta_wipe(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
 665 {
 666         struct gfs2_sbd *sdp = ip->i_sbd;
 667         struct inode *aspace = ip->i_gl->gl_aspace;
 668         struct buffer_head *bh;
 669
 670         while (blen) {
 671                 bh = getbuf(sdp, aspace, bstart, NO_CREATE);
 672                 if (bh) {
 673                         struct gfs2_bufdata *bd = bh->b_private;
 674
 675                         if (test_clear_buffer_pinned(bh)) {
 676                                 struct gfs2_trans *tr = current->journal_info;
 677                                 gfs2_log_lock(sdp);
 678                                 list_del_init(&bd->bd_le.le_list);
 679                                 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
 680                                 sdp->sd_log_num_buf--;
 681                                 gfs2_log_unlock(sdp);
 682                                 tr->tr_num_buf_rm++;
 683                                 brelse(bh);
 684                         }
 685                         if (bd) {
 686                                 gfs2_log_lock(sdp);
 687                                 if (bd->bd_ail) {
 688                                         uint64_t blkno = bh->b_blocknr;
 689                                         bd->bd_ail = NULL;
 690                                         list_del(&bd->bd_ail_st_list);
 691                                         list_del(&bd->bd_ail_gl_list);
 692                                         atomic_dec(&bd->bd_gl->gl_ail_count);
 693                                         brelse(bh);
 694                                         gfs2_log_unlock(sdp);
 695                                         gfs2_trans_add_revoke(sdp, blkno);
 696                                 } else
 697                                         gfs2_log_unlock(sdp);
 698                         }
 699
 700                         lock_buffer(bh);
 701                         clear_buffer_dirty(bh);
 702                         clear_buffer_uptodate(bh);
 703                         unlock_buffer(bh);
 704
 705                         brelse(bh);
 706                 }
 707
 708                 bstart++;
 709                 blen--;
 710         }
 711 }
 712
 713 /**
 714  * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
 715  * @ip: The GFS2 inode
 716  *
 717  * This releases buffers that are in the most-recently-used array of
 718  * blocks used for indirect block addressing for this inode.
 719  */
 720
 721 void gfs2_meta_cache_flush(struct gfs2_inode *ip)
 722 {
 723         struct buffer_head **bh_slot;
 724         unsigned int x;
 725
 726         spin_lock(&ip->i_spin);
 727
 728         for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
 729                 bh_slot = &ip->i_cache[x];
 730                 if (!*bh_slot)
 731                         break;
 732                 brelse(*bh_slot);
 733                 *bh_slot = NULL;
 734         }
 735
 736         spin_unlock(&ip->i_spin);
 737 }
 738
 739 /**
 740  * gfs2_meta_indirect_buffer - Get a metadata buffer
 741  * @ip: The GFS2 inode
 742  * @height: The level of this buf in the metadata (indir addr) tree (if any)
 743  * @num: The block number (device relative) of the buffer
 744  * @new: Non-zero if we may create a new buffer
 745  * @bhp: the buffer is returned here
 746  *
 747  * Try to use the gfs2_inode's MRU metadata tree cache.
 748  *
 749  * Returns: errno
 750  */
 751
 752 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, uint64_t num,
 753                               int new, struct buffer_head **bhp)
 754 {
 755         struct buffer_head *bh, **bh_slot = ip->i_cache + height;
 756         int error;
 757
 758         spin_lock(&ip->i_spin);
 759         bh = *bh_slot;
 760         if (bh) {
 761                 if (bh->b_blocknr == num)
 762                         get_bh(bh);
 763                 else
 764                         bh = NULL;
 765         }
 766         spin_unlock(&ip->i_spin);
 767
 768         if (bh) {
 769                 if (new)
 770                         meta_prep_new(bh);
 771                 else {
 772                         error = gfs2_meta_reread(ip->i_sbd, bh,
 773                                                  DIO_START | DIO_WAIT);
 774                         if (error) {
 775                                 brelse(bh);
 776                                 return error;
 777                         }
 778                 }
 779         } else {
 780                 if (new)
 781                         bh = gfs2_meta_new(ip->i_gl, num);
 782                 else {
 783                         error = gfs2_meta_read(ip->i_gl, num,
 784                                                DIO_START | DIO_WAIT, &bh);
 785                         if (error)
 786                                 return error;
 787                 }
 788
 789                 spin_lock(&ip->i_spin);
 790                 if (*bh_slot != bh) {
 791                         brelse(*bh_slot);
 792                         *bh_slot = bh;
 793                         get_bh(bh);
 794                 }
 795                 spin_unlock(&ip->i_spin);
 796         }
 797
 798         if (new) {
 799                 if (gfs2_assert_warn(ip->i_sbd, height)) {
 800                         brelse(bh);
 801                         return -EIO;
 802                 }
 803                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 804                 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
 805                 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 806
 807         } else if (gfs2_metatype_check(ip->i_sbd, bh,
 808                              (height) ? GFS2_METATYPE_IN : GFS2_METATYPE_DI)) {
 809                 brelse(bh);
 810                 return -EIO;
 811         }
 812
 813         *bhp = bh;
 814
 815         return 0;
 816 }
 817
 818 /**
 819  * gfs2_meta_ra - start readahead on an extent of a file
 820  * @gl: the glock the blocks belong to
 821  * @dblock: the starting disk block
 822  * @extlen: the number of blocks in the extent
 823  *
 824  */
 825
 826 void gfs2_meta_ra(struct gfs2_glock *gl, uint64_t dblock, uint32_t extlen)
 827 {
 828         struct gfs2_sbd *sdp = gl->gl_sbd;
 829         struct inode *aspace = gl->gl_aspace;
 830         struct buffer_head *first_bh, *bh;
 831         uint32_t max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 832                           sdp->sd_sb.sb_bsize_shift;
 833         int error;
 834
 835         if (!extlen || !max_ra)
 836                 return;
 837         if (extlen > max_ra)
 838                 extlen = max_ra;
 839
 840         first_bh = getbuf(sdp, aspace, dblock, CREATE);
 841
 842         if (buffer_uptodate(first_bh))
 843                 goto out;
 844         if (!buffer_locked(first_bh)) {
 845                 error = gfs2_meta_reread(sdp, first_bh, DIO_START);
 846                 if (error)
 847                         goto out;
 848         }
 849
 850         dblock++;
 851         extlen--;
 852
 853         while (extlen) {
 854                 bh = getbuf(sdp, aspace, dblock, CREATE);
 855
 856                 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
 857                         error = gfs2_meta_reread(sdp, bh, DIO_START);
 858                         brelse(bh);
 859                         if (error)
 860                                 goto out;
 861                 } else
 862                         brelse(bh);
 863
 864                 dblock++;
 865                 extlen--;
 866
 867                 if (buffer_uptodate(first_bh))
 868                         break;
 869         }
 870
 871  out:
 872         brelse(first_bh);
 873 }
 874
 875 /**
 876  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 877  * @sdp: the filesystem
 878  *
 879  */
 880
 881 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 882 {
 883         gfs2_log_flush(sdp, NULL);
 884         for (;;) {
 885                 gfs2_ail1_start(sdp, DIO_ALL);
 886                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 887                         break;
 888                 msleep(10);
 889         }
 890 }
 891