err.no Git - linux-2.6/blob - fs/gfs2/ops_address.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/pagemap.h>
  16 #include <linux/pagevec.h>
  17 #include <linux/mpage.h>
  18 #include <linux/fs.h>
  19 #include <linux/gfs2_ondisk.h>
  20 #include <asm/semaphore.h>
  21
  22 #include "gfs2.h"
  23 #include "lm_interface.h"
  24 #include "incore.h"
  25 #include "bmap.h"
  26 #include "glock.h"
  27 #include "inode.h"
  28 #include "log.h"
  29 #include "meta_io.h"
  30 #include "ops_address.h"
  31 #include "page.h"
  32 #include "quota.h"
  33 #include "trans.h"
  34 #include "rgrp.h"
  35 #include "ops_file.h"
  36 #include "util.h"
  37
  38 /**
  39  * gfs2_get_block - Fills in a buffer head with details about a block
  40  * @inode: The inode
  41  * @lblock: The block number to look up
  42  * @bh_result: The buffer head to return the result in
  43  * @create: Non-zero if we may add block to the file
  44  *
  45  * Returns: errno
  46  */
  47
  48 int gfs2_get_block(struct inode *inode, sector_t lblock,
  49                    struct buffer_head *bh_result, int create)
  50 {
  51         int new = create;
  52         uint64_t dblock;
  53         int error;
  54         int boundary;
  55
  56         error = gfs2_block_map(inode, lblock, &new, &dblock, &boundary);
  57         if (error)
  58                 return error;
  59
  60         if (!dblock)
  61                 return 0;
  62
  63         map_bh(bh_result, inode->i_sb, dblock);
  64         if (new)
  65                 set_buffer_new(bh_result);
  66         if (boundary)
  67                 set_buffer_boundary(bh_result);
  68
  69         return 0;
  70 }
  71
  72 /**
  73  * get_block_noalloc - Fills in a buffer head with details about a block
  74  * @inode: The inode
  75  * @lblock: The block number to look up
  76  * @bh_result: The buffer head to return the result in
  77  * @create: Non-zero if we may add block to the file
  78  *
  79  * Returns: errno
  80  */
  81
  82 static int get_block_noalloc(struct inode *inode, sector_t lblock,
  83                              struct buffer_head *bh_result, int create)
  84 {
  85         struct gfs2_inode *ip = inode->u.generic_ip;
  86         int new = 0;
  87         uint64_t dblock;
  88         int error;
  89         int boundary;
  90
  91         error = gfs2_block_map(inode, lblock, &new, &dblock, &boundary);
  92         if (error)
  93                 return error;
  94
  95         if (dblock)
  96                 map_bh(bh_result, inode->i_sb, dblock);
  97         else if (gfs2_assert_withdraw(ip->i_sbd, !create))
  98                 error = -EIO;
  99         if (boundary)
 100                 set_buffer_boundary(bh_result);
 101
 102         return error;
 103 }
 104
 105 /**
 106  * gfs2_writepage - Write complete page
 107  * @page: Page to write
 108  *
 109  * Returns: errno
 110  *
 111  * Some of this is copied from block_write_full_page() although we still
 112  * call it to do most of the work.
 113  */
 114
 115 static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
 116 {
 117         struct inode *inode = page->mapping->host;
 118         struct gfs2_inode *ip = page->mapping->host->u.generic_ip;
 119         struct gfs2_sbd *sdp = ip->i_sbd;
 120         loff_t i_size = i_size_read(inode);
 121         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
 122         unsigned offset;
 123         int error;
 124         int done_trans = 0;
 125
 126         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) {
 127                 unlock_page(page);
 128                 return -EIO;
 129         }
 130         if (current->journal_info)
 131                 goto out_ignore;
 132
 133         /* Is the page fully outside i_size? (truncate in progress) */
 134         offset = i_size & (PAGE_CACHE_SIZE-1);
 135         if (page->index > end_index || (page->index == end_index && !offset)) {
 136                 page->mapping->a_ops->invalidatepage(page, 0);
 137                 unlock_page(page);
 138                 return 0; /* don't care */
 139         }
 140
 141         if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) {
 142                 error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0);
 143                 if (error)
 144                         goto out_ignore;
 145                 gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
 146                 done_trans = 1;
 147         }
 148         error = block_write_full_page(page, get_block_noalloc, wbc);
 149         if (done_trans)
 150                 gfs2_trans_end(sdp);
 151         gfs2_meta_cache_flush(ip);
 152         return error;
 153
 154 out_ignore:
 155         redirty_page_for_writepage(wbc, page);
 156         unlock_page(page);
 157         return 0;
 158 }
 159
 160 static int zero_readpage(struct page *page)
 161 {
 162         void *kaddr;
 163
 164         kaddr = kmap_atomic(page, KM_USER0);
 165         memset(kaddr, 0, PAGE_CACHE_SIZE);
 166         kunmap_atomic(page, KM_USER0);
 167
 168         SetPageUptodate(page);
 169
 170         return 0;
 171 }
 172
 173 /**
 174  * stuffed_readpage - Fill in a Linux page with stuffed file data
 175  * @ip: the inode
 176  * @page: the page
 177  *
 178  * Returns: errno
 179  */
 180
 181 static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 182 {
 183         struct buffer_head *dibh;
 184         void *kaddr;
 185         int error;
 186
 187         /* Only the first page of a stuffed file might contain data */
 188         if (unlikely(page->index))
 189                 return zero_readpage(page);
 190
 191         error = gfs2_meta_inode_buffer(ip, &dibh);
 192         if (error)
 193                 return error;
 194
 195         kaddr = kmap_atomic(page, KM_USER0);
 196         memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode),
 197                ip->i_di.di_size);
 198         memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size);
 199         kunmap_atomic(page, KM_USER0);
 200
 201         brelse(dibh);
 202
 203         SetPageUptodate(page);
 204
 205         return 0;
 206 }
 207
 208
 209 /**
 210  * gfs2_readpage - readpage with locking
 211  * @file: The file to read a page for. N.B. This may be NULL if we are
 212  * reading an internal file.
 213  * @page: The page to read
 214  *
 215  * Returns: errno
 216  */
 217
 218 static int gfs2_readpage(struct file *file, struct page *page)
 219 {
 220         struct gfs2_inode *ip = page->mapping->host->u.generic_ip;
 221         struct gfs2_sbd *sdp = ip->i_sbd;
 222         struct gfs2_holder gh;
 223         int error;
 224
 225         if (likely(file != &gfs2_internal_file_sentinal)) {
 226                 gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh);
 227                 error = gfs2_glock_nq_m_atime(1, &gh);
 228                 if (unlikely(error))
 229                         goto out_unlock;
 230         }
 231
 232         if (gfs2_is_stuffed(ip)) {
 233                 error = stuffed_readpage(ip, page);
 234                 unlock_page(page);
 235         } else
 236                 error = mpage_readpage(page, gfs2_get_block);
 237
 238         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 239                 error = -EIO;
 240
 241         if (file != &gfs2_internal_file_sentinal) {
 242                 gfs2_glock_dq_m(1, &gh);
 243                 gfs2_holder_uninit(&gh);
 244         }
 245 out:
 246         return error;
 247 out_unlock:
 248         unlock_page(page);
 249         if (file != &gfs2_internal_file_sentinal)
 250                 gfs2_holder_uninit(&gh);
 251         goto out;
 252 }
 253
 254 #define list_to_page(head) (list_entry((head)->prev, struct page, lru))
 255
 256 /**
 257  * gfs2_readpages - Read a bunch of pages at once
 258  *
 259  * Some notes:
 260  * 1. This is only for readahead, so we can simply ignore any things
 261  *    which are slightly inconvenient (such as locking conflicts between
 262  *    the page lock and the glock) and return having done no I/O. Its
 263  *    obviously not something we'd want to do on too regular a basis.
 264  *    Any I/O we ignore at this time will be done via readpage later.
 265  * 2. We have to handle stuffed files here too.
 266  * 3. mpage_readpages() does most of the heavy lifting in the common case.
 267  * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
 268  * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
 269  *    well as read-ahead.
 270  */
 271 static int gfs2_readpages(struct file *file, struct address_space *mapping,
 272                           struct list_head *pages, unsigned nr_pages)
 273 {
 274         struct inode *inode = mapping->host;
 275         struct gfs2_inode *ip = inode->u.generic_ip;
 276         struct gfs2_sbd *sdp = ip->i_sbd;
 277         struct gfs2_holder gh;
 278         unsigned page_idx;
 279         int ret;
 280
 281         if (likely(file != &gfs2_internal_file_sentinal)) {
 282                 gfs2_holder_init(ip->i_gl, LM_ST_SHARED,
 283                                  LM_FLAG_TRY_1CB|GL_ATIME|GL_AOP, &gh);
 284                 ret = gfs2_glock_nq_m_atime(1, &gh);
 285                 if (ret == GLR_TRYFAILED)
 286                         goto out_noerror;
 287                 if (unlikely(ret))
 288                         goto out_unlock;
 289         }
 290
 291         if (gfs2_is_stuffed(ip)) {
 292                 struct pagevec lru_pvec;
 293                 pagevec_init(&lru_pvec, 0);
 294                 for (page_idx = 0; page_idx < nr_pages; page_idx++) {
 295                         struct page *page = list_to_page(pages);
 296                         list_del(&page->lru);
 297                         if (!add_to_page_cache(page, mapping,
 298                                                page->index, GFP_KERNEL)) {
 299                                 ret = stuffed_readpage(ip, page);
 300                                 unlock_page(page);
 301                                 if (!pagevec_add(&lru_pvec, page))
 302                                          __pagevec_lru_add(&lru_pvec);
 303                         }
 304                         page_cache_release(page);
 305                 }
 306                 pagevec_lru_add(&lru_pvec);
 307                 ret = 0;
 308         } else {
 309                 /* What we really want to do .... */
 310                 ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block);
 311         }
 312
 313         if (likely(file != &gfs2_internal_file_sentinal)) {
 314                 gfs2_glock_dq_m(1, &gh);
 315                 gfs2_holder_uninit(&gh);
 316         }
 317 out:
 318         if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 319                 ret = -EIO;
 320         return ret;
 321 out_noerror:
 322         ret = 0;
 323 out_unlock:
 324         /* unlock all pages, we can't do any I/O right now */
 325         for (page_idx = 0; page_idx < nr_pages; page_idx++) {
 326                 struct page *page = list_to_page(pages);
 327                 list_del(&page->lru);
 328                 unlock_page(page);
 329                 page_cache_release(page);
 330         }
 331         if (likely(file != &gfs2_internal_file_sentinal))
 332                 gfs2_holder_uninit(&gh);
 333         goto out;
 334 }
 335
 336 /**
 337  * gfs2_prepare_write - Prepare to write a page to a file
 338  * @file: The file to write to
 339  * @page: The page which is to be prepared for writing
 340  * @from: From (byte range within page)
 341  * @to: To (byte range within page)
 342  *
 343  * Returns: errno
 344  */
 345
 346 static int gfs2_prepare_write(struct file *file, struct page *page,
 347                               unsigned from, unsigned to)
 348 {
 349         struct gfs2_inode *ip = page->mapping->host->u.generic_ip;
 350         struct gfs2_sbd *sdp = ip->i_sbd;
 351         unsigned int data_blocks, ind_blocks, rblocks;
 352         int alloc_required;
 353         int error = 0;
 354         loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
 355         loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
 356         struct gfs2_alloc *al;
 357
 358         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh);
 359         error = gfs2_glock_nq_m_atime(1, &ip->i_gh);
 360         if (error)
 361                 goto out_uninit;
 362
 363         gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks);
 364
 365         error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required);
 366         if (error)
 367                 goto out_unlock;
 368
 369
 370         if (alloc_required) {
 371                 al = gfs2_alloc_get(ip);
 372
 373                 error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
 374                 if (error)
 375                         goto out_alloc_put;
 376
 377                 error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid);
 378                 if (error)
 379                         goto out_qunlock;
 380
 381                 al->al_requested = data_blocks + ind_blocks;
 382                 error = gfs2_inplace_reserve(ip);
 383                 if (error)
 384                         goto out_qunlock;
 385         }
 386
 387         rblocks = RES_DINODE + ind_blocks;
 388         if (gfs2_is_jdata(ip))
 389                 rblocks += data_blocks ? data_blocks : 1;
 390         if (ind_blocks || data_blocks)
 391                 rblocks += RES_STATFS + RES_QUOTA;
 392
 393         error = gfs2_trans_begin(sdp, rblocks, 0);
 394         if (error)
 395                 goto out;
 396
 397         if (gfs2_is_stuffed(ip)) {
 398                 if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
 399                         error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page,
 400                                                     page);
 401                         if (error == 0)
 402                                 goto prepare_write;
 403                 } else if (!PageUptodate(page))
 404                         error = stuffed_readpage(ip, page);
 405                 goto out;
 406         }
 407
 408 prepare_write:
 409         error = block_prepare_write(page, from, to, gfs2_get_block);
 410
 411 out:
 412         if (error) {
 413                 gfs2_trans_end(sdp);
 414                 if (alloc_required) {
 415                         gfs2_inplace_release(ip);
 416 out_qunlock:
 417                         gfs2_quota_unlock(ip);
 418 out_alloc_put:
 419                         gfs2_alloc_put(ip);
 420                 }
 421 out_unlock:
 422                 gfs2_glock_dq_m(1, &ip->i_gh);
 423 out_uninit:
 424                 gfs2_holder_uninit(&ip->i_gh);
 425         }
 426
 427         return error;
 428 }
 429
 430 /**
 431  * gfs2_commit_write - Commit write to a file
 432  * @file: The file to write to
 433  * @page: The page containing the data
 434  * @from: From (byte range within page)
 435  * @to: To (byte range within page)
 436  *
 437  * Returns: errno
 438  */
 439
 440 static int gfs2_commit_write(struct file *file, struct page *page,
 441                              unsigned from, unsigned to)
 442 {
 443         struct inode *inode = page->mapping->host;
 444         struct gfs2_inode *ip = inode->u.generic_ip;
 445         struct gfs2_sbd *sdp = ip->i_sbd;
 446         int error = -EOPNOTSUPP;
 447         struct buffer_head *dibh;
 448         struct gfs2_alloc *al = &ip->i_alloc;;
 449
 450         if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
 451                 goto fail_nounlock;
 452
 453         error = gfs2_meta_inode_buffer(ip, &dibh);
 454         if (error)
 455                 goto fail_endtrans;
 456
 457         gfs2_trans_add_bh(ip->i_gl, dibh, 1);
 458
 459         if (gfs2_is_stuffed(ip)) {
 460                 uint64_t file_size;
 461                 void *kaddr;
 462
 463                 file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to;
 464
 465                 kaddr = kmap_atomic(page, KM_USER0);
 466                 memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from,
 467                        (char *)kaddr + from, to - from);
 468                 kunmap_atomic(page, KM_USER0);
 469
 470                 SetPageUptodate(page);
 471
 472                 if (inode->i_size < file_size)
 473                         i_size_write(inode, file_size);
 474         } else {
 475                 if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED ||
 476                     gfs2_is_jdata(ip))
 477                         gfs2_page_add_databufs(ip, page, from, to);
 478                 error = generic_commit_write(file, page, from, to);
 479                 if (error)
 480                         goto fail;
 481         }
 482
 483         if (ip->i_di.di_size < inode->i_size)
 484                 ip->i_di.di_size = inode->i_size;
 485
 486         gfs2_dinode_out(&ip->i_di, dibh->b_data);
 487         brelse(dibh);
 488         gfs2_trans_end(sdp);
 489         if (al->al_requested) {
 490                 gfs2_inplace_release(ip);
 491                 gfs2_quota_unlock(ip);
 492                 gfs2_alloc_put(ip);
 493         }
 494         gfs2_glock_dq_m(1, &ip->i_gh);
 495         gfs2_holder_uninit(&ip->i_gh);
 496         return 0;
 497
 498 fail:
 499         brelse(dibh);
 500 fail_endtrans:
 501         gfs2_trans_end(sdp);
 502         if (al->al_requested) {
 503                 gfs2_inplace_release(ip);
 504                 gfs2_quota_unlock(ip);
 505                 gfs2_alloc_put(ip);
 506         }
 507         gfs2_glock_dq_m(1, &ip->i_gh);
 508         gfs2_holder_uninit(&ip->i_gh);
 509 fail_nounlock:
 510         ClearPageUptodate(page);
 511         return error;
 512 }
 513
 514 /**
 515  * gfs2_bmap - Block map function
 516  * @mapping: Address space info
 517  * @lblock: The block to map
 518  *
 519  * Returns: The disk address for the block or 0 on hole or error
 520  */
 521
 522 static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock)
 523 {
 524         struct gfs2_inode *ip = mapping->host->u.generic_ip;
 525         struct gfs2_holder i_gh;
 526         sector_t dblock = 0;
 527         int error;
 528
 529         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
 530         if (error)
 531                 return 0;
 532
 533         if (!gfs2_is_stuffed(ip))
 534                 dblock = generic_block_bmap(mapping, lblock, gfs2_get_block);
 535
 536         gfs2_glock_dq_uninit(&i_gh);
 537
 538         return dblock;
 539 }
 540
 541 static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh)
 542 {
 543         struct gfs2_bufdata *bd;
 544
 545         gfs2_log_lock(sdp);
 546         bd = bh->b_private;
 547         if (bd) {
 548                 bd->bd_bh = NULL;
 549                 bh->b_private = NULL;
 550                 gfs2_log_unlock(sdp);
 551                 brelse(bh);
 552         } else
 553                 gfs2_log_unlock(sdp);
 554
 555         lock_buffer(bh);
 556         clear_buffer_dirty(bh);
 557         bh->b_bdev = NULL;
 558         clear_buffer_mapped(bh);
 559         clear_buffer_req(bh);
 560         clear_buffer_new(bh);
 561         clear_buffer_delay(bh);
 562         unlock_buffer(bh);
 563 }
 564
 565 static void gfs2_invalidatepage(struct page *page, unsigned long offset)
 566 {
 567         struct gfs2_sbd *sdp = page->mapping->host->i_sb->s_fs_info;
 568         struct buffer_head *head, *bh, *next;
 569         unsigned int curr_off = 0;
 570
 571         BUG_ON(!PageLocked(page));
 572         if (!page_has_buffers(page))
 573                 return;
 574
 575         bh = head = page_buffers(page);
 576         do {
 577                 unsigned int next_off = curr_off + bh->b_size;
 578                 next = bh->b_this_page;
 579
 580                 if (offset <= curr_off)
 581                         discard_buffer(sdp, bh);
 582
 583                 curr_off = next_off;
 584                 bh = next;
 585         } while (bh != head);
 586
 587         if (!offset)
 588                 try_to_release_page(page, 0);
 589
 590         return;
 591 }
 592
 593 static ssize_t gfs2_direct_IO_write(struct kiocb *iocb, const struct iovec *iov,
 594                                     loff_t offset, unsigned long nr_segs)
 595 {
 596         struct file *file = iocb->ki_filp;
 597         struct inode *inode = file->f_mapping->host;
 598         struct gfs2_inode *ip = inode->u.generic_ip;
 599         struct gfs2_holder gh;
 600         int rv;
 601
 602         /*
 603          * Shared lock, even though its write, since we do no allocation
 604          * on this path. All we need change is atime.
 605          */
 606         gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
 607         rv = gfs2_glock_nq_m_atime(1, &gh);
 608         if (rv)
 609                 goto out;
 610
 611         /*
 612          * Should we return an error here? I can't see that O_DIRECT for
 613          * a journaled file makes any sense. For now we'll silently fall
 614          * back to buffered I/O, likewise we do the same for stuffed
 615          * files since they are (a) small and (b) unaligned.
 616          */
 617         if (gfs2_is_jdata(ip))
 618                 goto out;
 619
 620         if (gfs2_is_stuffed(ip))
 621                 goto out;
 622
 623         rv = __blockdev_direct_IO(WRITE, iocb, inode, inode->i_sb->s_bdev,
 624                                   iov, offset, nr_segs, gfs2_get_block,
 625                                   NULL, DIO_OWN_LOCKING);
 626 out:
 627         gfs2_glock_dq_m(1, &gh);
 628         gfs2_holder_uninit(&gh);
 629
 630         return rv;
 631 }
 632
 633 /**
 634  * gfs2_direct_IO
 635  *
 636  * This is called with a shared lock already held for the read path.
 637  * Currently, no locks are held when the write path is called.
 638  */
 639 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
 640                               const struct iovec *iov, loff_t offset,
 641                               unsigned long nr_segs)
 642 {
 643         struct file *file = iocb->ki_filp;
 644         struct inode *inode = file->f_mapping->host;
 645         struct gfs2_inode *ip = inode->u.generic_ip;
 646         struct gfs2_sbd *sdp = ip->i_sbd;
 647
 648         if (rw == WRITE)
 649                 return gfs2_direct_IO_write(iocb, iov, offset, nr_segs);
 650
 651         if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) ||
 652             gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
 653                 return -EINVAL;
 654
 655         return __blockdev_direct_IO(READ, iocb, inode, inode->i_sb->s_bdev, iov,
 656                                     offset, nr_segs, gfs2_get_block, NULL,
 657                                     DIO_OWN_LOCKING);
 658 }
 659
 660 struct address_space_operations gfs2_file_aops = {
 661         .writepage = gfs2_writepage,
 662         .readpage = gfs2_readpage,
 663         .readpages = gfs2_readpages,
 664         .sync_page = block_sync_page,
 665         .prepare_write = gfs2_prepare_write,
 666         .commit_write = gfs2_commit_write,
 667         .bmap = gfs2_bmap,
 668         .invalidatepage = gfs2_invalidatepage,
 669         .direct_IO = gfs2_direct_IO,
 670 };
 671