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 version 2.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/completion.h>
  14 #include <linux/buffer_head.h>
  15 #include <linux/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 <linux/lm_interface.h>
  22
  23 #include "gfs2.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 #include "ops_address.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 static const struct address_space_operations aspace_aops = {
  55         .writepage = gfs2_aspace_writepage,
  56         .releasepage = gfs2_releasepage,
  57 };
  58
  59 /**
  60  * gfs2_aspace_get - Create and initialize a struct inode structure
  61  * @sdp: the filesystem the aspace is in
  62  *
  63  * Right now a struct inode is just a struct inode.  Maybe Linux
  64  * will supply a more lightweight address space construct (that works)
  65  * in the future.
  66  *
  67  * Make sure pages/buffers in this aspace aren't in high memory.
  68  *
  69  * Returns: the aspace
  70  */
  71
  72 struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
  73 {
  74         struct inode *aspace;
  75
  76         aspace = new_inode(sdp->sd_vfs);
  77         if (aspace) {
  78                 mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
  79                 aspace->i_mapping->a_ops = &aspace_aops;
  80                 aspace->i_size = ~0ULL;
  81                 aspace->u.generic_ip = NULL;
  82                 insert_inode_hash(aspace);
  83         }
  84         return aspace;
  85 }
  86
  87 void gfs2_aspace_put(struct inode *aspace)
  88 {
  89         remove_inode_hash(aspace);
  90         iput(aspace);
  91 }
  92
  93 /**
  94  * gfs2_ail1_start_one - Start I/O on a part of the AIL
  95  * @sdp: the filesystem
  96  * @tr: the part of the AIL
  97  *
  98  */
  99
 100 void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 101 {
 102         struct gfs2_bufdata *bd, *s;
 103         struct buffer_head *bh;
 104         int retry;
 105
 106         BUG_ON(!spin_is_locked(&sdp->sd_log_lock));
 107
 108         do {
 109                 retry = 0;
 110
 111                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 112                                                  bd_ail_st_list) {
 113                         bh = bd->bd_bh;
 114
 115                         gfs2_assert(sdp, bd->bd_ail == ai);
 116
 117                         if (!buffer_busy(bh)) {
 118                                 if (!buffer_uptodate(bh)) {
 119                                         gfs2_log_unlock(sdp);
 120                                         gfs2_io_error_bh(sdp, bh);
 121                                         gfs2_log_lock(sdp);
 122                                 }
 123                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 124                                 continue;
 125                         }
 126
 127                         if (!buffer_dirty(bh))
 128                                 continue;
 129
 130                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 131
 132                         gfs2_log_unlock(sdp);
 133                         wait_on_buffer(bh);
 134                         ll_rw_block(WRITE, 1, &bh);
 135                         gfs2_log_lock(sdp);
 136
 137                         retry = 1;
 138                         break;
 139                 }
 140         } while (retry);
 141 }
 142
 143 /**
 144  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
 145  * @sdp: the filesystem
 146  * @ai: the AIL entry
 147  *
 148  */
 149
 150 int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
 151 {
 152         struct gfs2_bufdata *bd, *s;
 153         struct buffer_head *bh;
 154
 155         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
 156                                          bd_ail_st_list) {
 157                 bh = bd->bd_bh;
 158
 159                 gfs2_assert(sdp, bd->bd_ail == ai);
 160
 161                 if (buffer_busy(bh)) {
 162                         if (flags & DIO_ALL)
 163                                 continue;
 164                         else
 165                                 break;
 166                 }
 167
 168                 if (!buffer_uptodate(bh))
 169                         gfs2_io_error_bh(sdp, bh);
 170
 171                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 172         }
 173
 174         return list_empty(&ai->ai_ail1_list);
 175 }
 176
 177 /**
 178  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
 179  * @sdp: the filesystem
 180  * @ai: the AIL entry
 181  *
 182  */
 183
 184 void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
 185 {
 186         struct list_head *head = &ai->ai_ail2_list;
 187         struct gfs2_bufdata *bd;
 188
 189         while (!list_empty(head)) {
 190                 bd = list_entry(head->prev, struct gfs2_bufdata,
 191                                 bd_ail_st_list);
 192                 gfs2_assert(sdp, bd->bd_ail == ai);
 193                 bd->bd_ail = NULL;
 194                 list_del(&bd->bd_ail_st_list);
 195                 list_del(&bd->bd_ail_gl_list);
 196                 atomic_dec(&bd->bd_gl->gl_ail_count);
 197                 brelse(bd->bd_bh);
 198         }
 199 }
 200
 201 /**
 202  * ail_empty_gl - remove all buffers for a given lock from the AIL
 203  * @gl: the glock
 204  *
 205  * None of the buffers should be dirty, locked, or pinned.
 206  */
 207
 208 void gfs2_ail_empty_gl(struct gfs2_glock *gl)
 209 {
 210         struct gfs2_sbd *sdp = gl->gl_sbd;
 211         unsigned int blocks;
 212         struct list_head *head = &gl->gl_ail_list;
 213         struct gfs2_bufdata *bd;
 214         struct buffer_head *bh;
 215         u64 blkno;
 216         int error;
 217
 218         blocks = atomic_read(&gl->gl_ail_count);
 219         if (!blocks)
 220                 return;
 221
 222         error = gfs2_trans_begin(sdp, 0, blocks);
 223         if (gfs2_assert_withdraw(sdp, !error))
 224                 return;
 225
 226         gfs2_log_lock(sdp);
 227         while (!list_empty(head)) {
 228                 bd = list_entry(head->next, struct gfs2_bufdata,
 229                                 bd_ail_gl_list);
 230                 bh = bd->bd_bh;
 231                 blkno = bh->b_blocknr;
 232                 gfs2_assert_withdraw(sdp, !buffer_busy(bh));
 233
 234                 bd->bd_ail = NULL;
 235                 list_del(&bd->bd_ail_st_list);
 236                 list_del(&bd->bd_ail_gl_list);
 237                 atomic_dec(&gl->gl_ail_count);
 238                 brelse(bh);
 239                 gfs2_log_unlock(sdp);
 240
 241                 gfs2_trans_add_revoke(sdp, blkno);
 242
 243                 gfs2_log_lock(sdp);
 244         }
 245         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 246         gfs2_log_unlock(sdp);
 247
 248         gfs2_trans_end(sdp);
 249         gfs2_log_flush(sdp, NULL);
 250 }
 251
 252 /**
 253  * gfs2_meta_inval - Invalidate all buffers associated with a glock
 254  * @gl: the glock
 255  *
 256  */
 257
 258 void gfs2_meta_inval(struct gfs2_glock *gl)
 259 {
 260         struct gfs2_sbd *sdp = gl->gl_sbd;
 261         struct inode *aspace = gl->gl_aspace;
 262         struct address_space *mapping = gl->gl_aspace->i_mapping;
 263
 264         gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
 265
 266         atomic_inc(&aspace->i_writecount);
 267         truncate_inode_pages(mapping, 0);
 268         atomic_dec(&aspace->i_writecount);
 269
 270         gfs2_assert_withdraw(sdp, !mapping->nrpages);
 271 }
 272
 273 /**
 274  * gfs2_meta_sync - Sync all buffers associated with a glock
 275  * @gl: The glock
 276  * @flags: DIO_START | DIO_WAIT
 277  *
 278  */
 279
 280 void gfs2_meta_sync(struct gfs2_glock *gl, int flags)
 281 {
 282         struct address_space *mapping = gl->gl_aspace->i_mapping;
 283         int error = 0;
 284
 285         if (flags & DIO_START)
 286                 filemap_fdatawrite(mapping);
 287         if (!error && (flags & DIO_WAIT))
 288                 error = filemap_fdatawait(mapping);
 289
 290         if (error)
 291                 gfs2_io_error(gl->gl_sbd);
 292 }
 293
 294 /**
 295  * getbuf - Get a buffer with a given address space
 296  * @sdp: the filesystem
 297  * @aspace: the address space
 298  * @blkno: the block number (filesystem scope)
 299  * @create: 1 if the buffer should be created
 300  *
 301  * Returns: the buffer
 302  */
 303
 304 static struct buffer_head *getbuf(struct gfs2_sbd *sdp, struct inode *aspace,
 305                                   u64 blkno, int create)
 306 {
 307         struct page *page;
 308         struct buffer_head *bh;
 309         unsigned int shift;
 310         unsigned long index;
 311         unsigned int bufnum;
 312
 313         shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
 314         index = blkno >> shift;             /* convert block to page */
 315         bufnum = blkno - (index << shift);  /* block buf index within page */
 316
 317         if (create) {
 318                 for (;;) {
 319                         page = grab_cache_page(aspace->i_mapping, index);
 320                         if (page)
 321                                 break;
 322                         yield();
 323                 }
 324         } else {
 325                 page = find_lock_page(aspace->i_mapping, index);
 326                 if (!page)
 327                         return NULL;
 328         }
 329
 330         if (!page_has_buffers(page))
 331                 create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
 332
 333         /* Locate header for our buffer within our page */
 334         for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
 335                 /* Do nothing */;
 336         get_bh(bh);
 337
 338         if (!buffer_mapped(bh))
 339                 map_bh(bh, sdp->sd_vfs, blkno);
 340
 341         unlock_page(page);
 342         mark_page_accessed(page);
 343         page_cache_release(page);
 344
 345         return bh;
 346 }
 347
 348 static void meta_prep_new(struct buffer_head *bh)
 349 {
 350         struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
 351
 352         lock_buffer(bh);
 353         clear_buffer_dirty(bh);
 354         set_buffer_uptodate(bh);
 355         unlock_buffer(bh);
 356
 357         mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
 358 }
 359
 360 /**
 361  * gfs2_meta_new - Get a block
 362  * @gl: The glock associated with this block
 363  * @blkno: The block number
 364  *
 365  * Returns: The buffer
 366  */
 367
 368 struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
 369 {
 370         struct buffer_head *bh;
 371         bh = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 372         meta_prep_new(bh);
 373         return bh;
 374 }
 375
 376 /**
 377  * gfs2_meta_read - Read a block from disk
 378  * @gl: The glock covering the block
 379  * @blkno: The block number
 380  * @flags: flags to gfs2_dreread()
 381  * @bhp: the place where the buffer is returned (NULL on failure)
 382  *
 383  * Returns: errno
 384  */
 385
 386 int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 387                    struct buffer_head **bhp)
 388 {
 389         int error;
 390
 391         *bhp = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
 392         error = gfs2_meta_reread(gl->gl_sbd, *bhp, flags);
 393         if (error)
 394                 brelse(*bhp);
 395
 396         return error;
 397 }
 398
 399 /**
 400  * gfs2_meta_reread - Reread a block from disk
 401  * @sdp: the filesystem
 402  * @bh: The block to read
 403  * @flags: Flags that control the read
 404  *
 405  * Returns: errno
 406  */
 407
 408 int gfs2_meta_reread(struct gfs2_sbd *sdp, struct buffer_head *bh, int flags)
 409 {
 410         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 411                 return -EIO;
 412
 413         if ((flags & DIO_START) && !buffer_uptodate(bh))
 414                 ll_rw_block(READ, 1, &bh);
 415
 416         if (flags & DIO_WAIT) {
 417                 wait_on_buffer(bh);
 418
 419                 if (!buffer_uptodate(bh)) {
 420                         struct gfs2_trans *tr = current->journal_info;
 421                         if (tr && tr->tr_touched)
 422                                 gfs2_io_error_bh(sdp, bh);
 423                         return -EIO;
 424                 }
 425                 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 426                         return -EIO;
 427         }
 428
 429         return 0;
 430 }
 431
 432 /**
 433  * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
 434  * @gl: the glock the buffer belongs to
 435  * @bh: The buffer to be attached to
 436  * @meta: Flag to indicate whether its metadata or not
 437  */
 438
 439 void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
 440                          int meta)
 441 {
 442         struct gfs2_bufdata *bd;
 443
 444         if (meta)
 445                 lock_page(bh->b_page);
 446
 447         if (bh->b_private) {
 448                 if (meta)
 449                         unlock_page(bh->b_page);
 450                 return;
 451         }
 452
 453         bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
 454         memset(bd, 0, sizeof(struct gfs2_bufdata));
 455         bd->bd_bh = bh;
 456         bd->bd_gl = gl;
 457
 458         INIT_LIST_HEAD(&bd->bd_list_tr);
 459         if (meta)
 460                 lops_init_le(&bd->bd_le, &gfs2_buf_lops);
 461         else
 462                 lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
 463         bh->b_private = bd;
 464
 465         if (meta)
 466                 unlock_page(bh->b_page);
 467 }
 468
 469 /**
 470  * gfs2_pin - Pin a buffer in memory
 471  * @sdp: the filesystem the buffer belongs to
 472  * @bh: The buffer to be pinned
 473  *
 474  */
 475
 476 void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
 477 {
 478         struct gfs2_bufdata *bd = bh->b_private;
 479
 480         gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
 481
 482         if (test_set_buffer_pinned(bh))
 483                 gfs2_assert_withdraw(sdp, 0);
 484
 485         wait_on_buffer(bh);
 486
 487         /* If this buffer is in the AIL and it has already been written
 488            to in-place disk block, remove it from the AIL. */
 489
 490         gfs2_log_lock(sdp);
 491         if (bd->bd_ail && !buffer_in_io(bh))
 492                 list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
 493         gfs2_log_unlock(sdp);
 494
 495         clear_buffer_dirty(bh);
 496         wait_on_buffer(bh);
 497
 498         if (!buffer_uptodate(bh))
 499                 gfs2_io_error_bh(sdp, bh);
 500
 501         get_bh(bh);
 502 }
 503
 504 /**
 505  * gfs2_unpin - Unpin a buffer
 506  * @sdp: the filesystem the buffer belongs to
 507  * @bh: The buffer to unpin
 508  * @ai:
 509  *
 510  */
 511
 512 void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
 513                 struct gfs2_ail *ai)
 514 {
 515         struct gfs2_bufdata *bd = bh->b_private;
 516
 517         gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
 518
 519         if (!buffer_pinned(bh))
 520                 gfs2_assert_withdraw(sdp, 0);
 521
 522         mark_buffer_dirty(bh);
 523         clear_buffer_pinned(bh);
 524
 525         gfs2_log_lock(sdp);
 526         if (bd->bd_ail) {
 527                 list_del(&bd->bd_ail_st_list);
 528                 brelse(bh);
 529         } else {
 530                 struct gfs2_glock *gl = bd->bd_gl;
 531                 list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
 532                 atomic_inc(&gl->gl_ail_count);
 533         }
 534         bd->bd_ail = ai;
 535         list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
 536         gfs2_log_unlock(sdp);
 537 }
 538
 539 /**
 540  * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
 541  * @ip: the inode who owns the buffers
 542  * @bstart: the first buffer in the run
 543  * @blen: the number of buffers in the run
 544  *
 545  */
 546
 547 void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
 548 {
 549         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 550         struct inode *aspace = ip->i_gl->gl_aspace;
 551         struct buffer_head *bh;
 552
 553         while (blen) {
 554                 bh = getbuf(sdp, aspace, bstart, NO_CREATE);
 555                 if (bh) {
 556                         struct gfs2_bufdata *bd = bh->b_private;
 557
 558                         if (test_clear_buffer_pinned(bh)) {
 559                                 struct gfs2_trans *tr = current->journal_info;
 560                                 gfs2_log_lock(sdp);
 561                                 list_del_init(&bd->bd_le.le_list);
 562                                 gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
 563                                 sdp->sd_log_num_buf--;
 564                                 gfs2_log_unlock(sdp);
 565                                 tr->tr_num_buf_rm++;
 566                                 brelse(bh);
 567                         }
 568                         if (bd) {
 569                                 gfs2_log_lock(sdp);
 570                                 if (bd->bd_ail) {
 571                                         u64 blkno = bh->b_blocknr;
 572                                         bd->bd_ail = NULL;
 573                                         list_del(&bd->bd_ail_st_list);
 574                                         list_del(&bd->bd_ail_gl_list);
 575                                         atomic_dec(&bd->bd_gl->gl_ail_count);
 576                                         brelse(bh);
 577                                         gfs2_log_unlock(sdp);
 578                                         gfs2_trans_add_revoke(sdp, blkno);
 579                                 } else
 580                                         gfs2_log_unlock(sdp);
 581                         }
 582
 583                         lock_buffer(bh);
 584                         clear_buffer_dirty(bh);
 585                         clear_buffer_uptodate(bh);
 586                         unlock_buffer(bh);
 587
 588                         brelse(bh);
 589                 }
 590
 591                 bstart++;
 592                 blen--;
 593         }
 594 }
 595
 596 /**
 597  * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
 598  * @ip: The GFS2 inode
 599  *
 600  * This releases buffers that are in the most-recently-used array of
 601  * blocks used for indirect block addressing for this inode.
 602  */
 603
 604 void gfs2_meta_cache_flush(struct gfs2_inode *ip)
 605 {
 606         struct buffer_head **bh_slot;
 607         unsigned int x;
 608
 609         spin_lock(&ip->i_spin);
 610
 611         for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
 612                 bh_slot = &ip->i_cache[x];
 613                 if (!*bh_slot)
 614                         break;
 615                 brelse(*bh_slot);
 616                 *bh_slot = NULL;
 617         }
 618
 619         spin_unlock(&ip->i_spin);
 620 }
 621
 622 /**
 623  * gfs2_meta_indirect_buffer - Get a metadata buffer
 624  * @ip: The GFS2 inode
 625  * @height: The level of this buf in the metadata (indir addr) tree (if any)
 626  * @num: The block number (device relative) of the buffer
 627  * @new: Non-zero if we may create a new buffer
 628  * @bhp: the buffer is returned here
 629  *
 630  * Try to use the gfs2_inode's MRU metadata tree cache.
 631  *
 632  * Returns: errno
 633  */
 634
 635 int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
 636                               int new, struct buffer_head **bhp)
 637 {
 638         struct buffer_head *bh, **bh_slot = ip->i_cache + height;
 639         int error;
 640
 641         spin_lock(&ip->i_spin);
 642         bh = *bh_slot;
 643         if (bh) {
 644                 if (bh->b_blocknr == num)
 645                         get_bh(bh);
 646                 else
 647                         bh = NULL;
 648         }
 649         spin_unlock(&ip->i_spin);
 650
 651         if (bh) {
 652                 if (new)
 653                         meta_prep_new(bh);
 654                 else {
 655                         error = gfs2_meta_reread(GFS2_SB(&ip->i_inode), bh,
 656                                                  DIO_START | DIO_WAIT);
 657                         if (error) {
 658                                 brelse(bh);
 659                                 return error;
 660                         }
 661                 }
 662         } else {
 663                 if (new)
 664                         bh = gfs2_meta_new(ip->i_gl, num);
 665                 else {
 666                         error = gfs2_meta_read(ip->i_gl, num,
 667                                                DIO_START | DIO_WAIT, &bh);
 668                         if (error)
 669                                 return error;
 670                 }
 671
 672                 spin_lock(&ip->i_spin);
 673                 if (*bh_slot != bh) {
 674                         brelse(*bh_slot);
 675                         *bh_slot = bh;
 676                         get_bh(bh);
 677                 }
 678                 spin_unlock(&ip->i_spin);
 679         }
 680
 681         if (new) {
 682                 if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), height)) {
 683                         brelse(bh);
 684                         return -EIO;
 685                 }
 686                 gfs2_trans_add_bh(ip->i_gl, bh, 1);
 687                 gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
 688                 gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
 689
 690         } else if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh,
 691                              (height) ? GFS2_METATYPE_IN : GFS2_METATYPE_DI)) {
 692                 brelse(bh);
 693                 return -EIO;
 694         }
 695
 696         *bhp = bh;
 697
 698         return 0;
 699 }
 700
 701 /**
 702  * gfs2_meta_ra - start readahead on an extent of a file
 703  * @gl: the glock the blocks belong to
 704  * @dblock: the starting disk block
 705  * @extlen: the number of blocks in the extent
 706  *
 707  */
 708
 709 void gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 710 {
 711         struct gfs2_sbd *sdp = gl->gl_sbd;
 712         struct inode *aspace = gl->gl_aspace;
 713         struct buffer_head *first_bh, *bh;
 714         u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
 715                           sdp->sd_sb.sb_bsize_shift;
 716         int error;
 717
 718         if (!extlen || !max_ra)
 719                 return;
 720         if (extlen > max_ra)
 721                 extlen = max_ra;
 722
 723         first_bh = getbuf(sdp, aspace, dblock, CREATE);
 724
 725         if (buffer_uptodate(first_bh))
 726                 goto out;
 727         if (!buffer_locked(first_bh)) {
 728                 error = gfs2_meta_reread(sdp, first_bh, DIO_START);
 729                 if (error)
 730                         goto out;
 731         }
 732
 733         dblock++;
 734         extlen--;
 735
 736         while (extlen) {
 737                 bh = getbuf(sdp, aspace, dblock, CREATE);
 738
 739                 if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
 740                         error = gfs2_meta_reread(sdp, bh, DIO_START);
 741                         brelse(bh);
 742                         if (error)
 743                                 goto out;
 744                 } else
 745                         brelse(bh);
 746
 747                 dblock++;
 748                 extlen--;
 749
 750                 if (buffer_uptodate(first_bh))
 751                         break;
 752         }
 753
 754 out:
 755         brelse(first_bh);
 756 }
 757
 758 /**
 759  * gfs2_meta_syncfs - sync all the buffers in a filesystem
 760  * @sdp: the filesystem
 761  *
 762  */
 763
 764 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
 765 {
 766         gfs2_log_flush(sdp, NULL);
 767         for (;;) {
 768                 gfs2_ail1_start(sdp, DIO_ALL);
 769                 if (gfs2_ail1_empty(sdp, DIO_ALL))
 770                         break;
 771                 msleep(10);
 772         }
 773 }
 774