fs/ocfs2/aops.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public
  17  * License along with this program; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 021110-1307, USA.
  20  */
  21
  22 #include <linux/fs.h>
  23 #include <linux/slab.h>
  24 #include <linux/highmem.h>
  25 #include <linux/pagemap.h>
  26 #include <asm/byteorder.h>
  27 #include <linux/swap.h>
  28 #include <linux/pipe_fs_i.h>
  29 #include <linux/mpage.h>
  30 #include <linux/quotaops.h>
  31
  32 #define MLOG_MASK_PREFIX ML_FILE_IO
  33 #include <cluster/masklog.h>
  34
  35 #include "ocfs2.h"
  36
  37 #include "alloc.h"
  38 #include "aops.h"
  39 #include "dlmglue.h"
  40 #include "extent_map.h"
  41 #include "file.h"
  42 #include "inode.h"
  43 #include "journal.h"
  44 #include "suballoc.h"
  45 #include "super.h"
  46 #include "symlink.h"
  47 #include "refcounttree.h"
  48
  49 #include "buffer_head_io.h"
  50
  51 static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
  52                                    struct buffer_head *bh_result, int create)
  53 {
  54         int err = -EIO;
  55         int status;
  56         struct ocfs2_dinode *fe = NULL;
  57         struct buffer_head *bh = NULL;
  58         struct buffer_head *buffer_cache_bh = NULL;
  59         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
  60         void *kaddr;
  61
  62         mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
  63                    (unsigned long long)iblock, bh_result, create);
  64
  65         BUG_ON(ocfs2_inode_is_fast_symlink(inode));
  66
  67         if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
  68                 mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
  69                      (unsigned long long)iblock);
  70                 goto bail;
  71         }
  72
  73         status = ocfs2_read_inode_block(inode, &bh);
  74         if (status < 0) {
  75                 mlog_errno(status);
  76                 goto bail;
  77         }
  78         fe = (struct ocfs2_dinode *) bh->b_data;
  79
  80         if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
  81                                                     le32_to_cpu(fe->i_clusters))) {
  82                 mlog(ML_ERROR, "block offset is outside the allocated size: "
  83                      "%llu\n", (unsigned long long)iblock);
  84                 goto bail;
  85         }
  86
  87         /* We don't use the page cache to create symlink data, so if
  88          * need be, copy it over from the buffer cache. */
  89         if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
  90                 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
  91                             iblock;
  92                 buffer_cache_bh = sb_getblk(osb->sb, blkno);
  93                 if (!buffer_cache_bh) {
  94                         mlog(ML_ERROR, "couldn't getblock for symlink!\n");
  95                         goto bail;
  96                 }
  97
  98                 /* we haven't locked out transactions, so a commit
  99                  * could've happened. Since we've got a reference on
 100                  * the bh, even if it commits while we're doing the
 101                  * copy, the data is still good. */
 102                 if (buffer_jbd(buffer_cache_bh)
 103                     && ocfs2_inode_is_new(inode)) {
 104                         kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
 105                         if (!kaddr) {
 106                                 mlog(ML_ERROR, "couldn't kmap!\n");
 107                                 goto bail;
 108                         }
 109                         memcpy(kaddr + (bh_result->b_size * iblock),
 110                                buffer_cache_bh->b_data,
 111                                bh_result->b_size);
 112                         kunmap_atomic(kaddr, KM_USER0);
 113                         set_buffer_uptodate(bh_result);
 114                 }
 115                 brelse(buffer_cache_bh);
 116         }
 117
 118         map_bh(bh_result, inode->i_sb,
 119                le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
 120
 121         err = 0;
 122
 123 bail:
 124         brelse(bh);
 125
 126         mlog_exit(err);
 127         return err;
 128 }
 129
 130 int ocfs2_get_block(struct inode *inode, sector_t iblock,
 131                     struct buffer_head *bh_result, int create)
 132 {
 133         int err = 0;
 134         unsigned int ext_flags;
 135         u64 max_blocks = bh_result->b_size >> inode->i_blkbits;
 136         u64 p_blkno, count, past_eof;
 137         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 138
 139         mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
 140                    (unsigned long long)iblock, bh_result, create);
 141
 142         if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
 143                 mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
 144                      inode, inode->i_ino);
 145
 146         if (S_ISLNK(inode->i_mode)) {
 147                 /* this always does I/O for some reason. */
 148                 err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
 149                 goto bail;
 150         }
 151
 152         err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &count,
 153                                           &ext_flags);
 154         if (err) {
 155                 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
 156                      "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
 157                      (unsigned long long)p_blkno);
 158                 goto bail;
 159         }
 160
 161         if (max_blocks < count)
 162                 count = max_blocks;
 163
 164         /*
 165          * ocfs2 never allocates in this function - the only time we
 166          * need to use BH_New is when we're extending i_size on a file
 167          * system which doesn't support holes, in which case BH_New
 168          * allows block_prepare_write() to zero.
 169          *
 170          * If we see this on a sparse file system, then a truncate has
 171          * raced us and removed the cluster. In this case, we clear
 172          * the buffers dirty and uptodate bits and let the buffer code
 173          * ignore it as a hole.
 174          */
 175         if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) {
 176                 clear_buffer_dirty(bh_result);
 177                 clear_buffer_uptodate(bh_result);
 178                 goto bail;
 179         }
 180
 181         /* Treat the unwritten extent as a hole for zeroing purposes. */
 182         if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 183                 map_bh(bh_result, inode->i_sb, p_blkno);
 184
 185         bh_result->b_size = count << inode->i_blkbits;
 186
 187         if (!ocfs2_sparse_alloc(osb)) {
 188                 if (p_blkno == 0) {
 189                         err = -EIO;
 190                         mlog(ML_ERROR,
 191                              "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
 192                              (unsigned long long)iblock,
 193                              (unsigned long long)p_blkno,
 194                              (unsigned long long)OCFS2_I(inode)->ip_blkno);
 195                         mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
 196                         dump_stack();
 197                         goto bail;
 198                 }
 199
 200                 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 201                 mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
 202                      (unsigned long long)past_eof);
 203
 204                 if (create && (iblock >= past_eof))
 205                         set_buffer_new(bh_result);
 206         }
 207
 208 bail:
 209         if (err < 0)
 210                 err = -EIO;
 211
 212         mlog_exit(err);
 213         return err;
 214 }
 215
 216 int ocfs2_read_inline_data(struct inode *inode, struct page *page,
 217                            struct buffer_head *di_bh)
 218 {
 219         void *kaddr;
 220         loff_t size;
 221         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 222
 223         if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) {
 224                 ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag",
 225                             (unsigned long long)OCFS2_I(inode)->ip_blkno);
 226                 return -EROFS;
 227         }
 228
 229         size = i_size_read(inode);
 230
 231         if (size > PAGE_CACHE_SIZE ||
 232             size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) {
 233                 ocfs2_error(inode->i_sb,
 234                             "Inode %llu has with inline data has bad size: %Lu",
 235                             (unsigned long long)OCFS2_I(inode)->ip_blkno,
 236                             (unsigned long long)size);
 237                 return -EROFS;
 238         }
 239
 240         kaddr = kmap_atomic(page, KM_USER0);
 241         if (size)
 242                 memcpy(kaddr, di->id2.i_data.id_data, size);
 243         /* Clear the remaining part of the page */
 244         memset(kaddr + size, 0, PAGE_CACHE_SIZE - size);
 245         flush_dcache_page(page);
 246         kunmap_atomic(kaddr, KM_USER0);
 247
 248         SetPageUptodate(page);
 249
 250         return 0;
 251 }
 252
 253 static int ocfs2_readpage_inline(struct inode *inode, struct page *page)
 254 {
 255         int ret;
 256         struct buffer_head *di_bh = NULL;
 257
 258         BUG_ON(!PageLocked(page));
 259         BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL));
 260
 261         ret = ocfs2_read_inode_block(inode, &di_bh);
 262         if (ret) {
 263                 mlog_errno(ret);
 264                 goto out;
 265         }
 266
 267         ret = ocfs2_read_inline_data(inode, page, di_bh);
 268 out:
 269         unlock_page(page);
 270
 271         brelse(di_bh);
 272         return ret;
 273 }
 274
 275 static int ocfs2_readpage(struct file *file, struct page *page)
 276 {
 277         struct inode *inode = page->mapping->host;
 278         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 279         loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
 280         int ret, unlock = 1;
 281
 282         mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
 283
 284         ret = ocfs2_inode_lock_with_page(inode, NULL, 0, page);
 285         if (ret != 0) {
 286                 if (ret == AOP_TRUNCATED_PAGE)
 287                         unlock = 0;
 288                 mlog_errno(ret);
 289                 goto out;
 290         }
 291
 292         if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 293                 ret = AOP_TRUNCATED_PAGE;
 294                 goto out_inode_unlock;
 295         }
 296
 297         /*
 298          * i_size might have just been updated as we grabed the meta lock.  We
 299          * might now be discovering a truncate that hit on another node.
 300          * block_read_full_page->get_block freaks out if it is asked to read
 301          * beyond the end of a file, so we check here.  Callers
 302          * (generic_file_read, vm_ops->fault) are clever enough to check i_size
 303          * and notice that the page they just read isn't needed.
 304          *
 305          * XXX sys_readahead() seems to get that wrong?
 306          */
 307         if (start >= i_size_read(inode)) {
 308                 zero_user(page, 0, PAGE_SIZE);
 309                 SetPageUptodate(page);
 310                 ret = 0;
 311                 goto out_alloc;
 312         }
 313
 314         if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 315                 ret = ocfs2_readpage_inline(inode, page);
 316         else
 317                 ret = block_read_full_page(page, ocfs2_get_block);
 318         unlock = 0;
 319
 320 out_alloc:
 321         up_read(&OCFS2_I(inode)->ip_alloc_sem);
 322 out_inode_unlock:
 323         ocfs2_inode_unlock(inode, 0);
 324 out:
 325         if (unlock)
 326                 unlock_page(page);
 327         mlog_exit(ret);
 328         return ret;
 329 }
 330
 331 /*
 332  * This is used only for read-ahead. Failures or difficult to handle
 333  * situations are safe to ignore.
 334  *
 335  * Right now, we don't bother with BH_Boundary - in-inode extent lists
 336  * are quite large (243 extents on 4k blocks), so most inodes don't
 337  * grow out to a tree. If need be, detecting boundary extents could
 338  * trivially be added in a future version of ocfs2_get_block().
 339  */
 340 static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
 341                            struct list_head *pages, unsigned nr_pages)
 342 {
 343         int ret, err = -EIO;
 344         struct inode *inode = mapping->host;
 345         struct ocfs2_inode_info *oi = OCFS2_I(inode);
 346         loff_t start;
 347         struct page *last;
 348
 349         /*
 350          * Use the nonblocking flag for the dlm code to avoid page
 351          * lock inversion, but don't bother with retrying.
 352          */
 353         ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK);
 354         if (ret)
 355                 return err;
 356
 357         if (down_read_trylock(&oi->ip_alloc_sem) == 0) {
 358                 ocfs2_inode_unlock(inode, 0);
 359                 return err;
 360         }
 361
 362         /*
 363          * Don't bother with inline-data. There isn't anything
 364          * to read-ahead in that case anyway...
 365          */
 366         if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 367                 goto out_unlock;
 368
 369         /*
 370          * Check whether a remote node truncated this file - we just
 371          * drop out in that case as it's not worth handling here.
 372          */
 373         last = list_entry(pages->prev, struct page, lru);
 374         start = (loff_t)last->index << PAGE_CACHE_SHIFT;
 375         if (start >= i_size_read(inode))
 376                 goto out_unlock;
 377
 378         err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block);
 379
 380 out_unlock:
 381         up_read(&oi->ip_alloc_sem);
 382         ocfs2_inode_unlock(inode, 0);
 383
 384         return err;
 385 }
 386
 387 /* Note: Because we don't support holes, our allocation has
 388  * already happened (allocation writes zeros to the file data)
 389  * so we don't have to worry about ordered writes in
 390  * ocfs2_writepage.
 391  *
 392  * ->writepage is called during the process of invalidating the page cache
 393  * during blocked lock processing.  It can't block on any cluster locks
 394  * to during block mapping.  It's relying on the fact that the block
 395  * mapping can't have disappeared under the dirty pages that it is
 396  * being asked to write back.
 397  */
 398 static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
 399 {
 400         int ret;
 401
 402         mlog_entry("(0x%p)\n", page);
 403
 404         ret = block_write_full_page(page, ocfs2_get_block, wbc);
 405
 406         mlog_exit(ret);
 407
 408         return ret;
 409 }
 410
 411 /*
 412  * This is called from ocfs2_write_zero_page() which has handled it's
 413  * own cluster locking and has ensured allocation exists for those
 414  * blocks to be written.
 415  */
 416 int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
 417                                unsigned from, unsigned to)
 418 {
 419         int ret;
 420
 421         ret = block_prepare_write(page, from, to, ocfs2_get_block);
 422
 423         return ret;
 424 }
 425
 426 /* Taken from ext3. We don't necessarily need the full blown
 427  * functionality yet, but IMHO it's better to cut and paste the whole
 428  * thing so we can avoid introducing our own bugs (and easily pick up
 429  * their fixes when they happen) --Mark */
 430 int walk_page_buffers(  handle_t *handle,
 431                         struct buffer_head *head,
 432                         unsigned from,
 433                         unsigned to,
 434                         int *partial,
 435                         int (*fn)(      handle_t *handle,
 436                                         struct buffer_head *bh))
 437 {
 438         struct buffer_head *bh;
 439         unsigned block_start, block_end;
 440         unsigned blocksize = head->b_size;
 441         int err, ret = 0;
 442         struct buffer_head *next;
 443
 444         for (   bh = head, block_start = 0;
 445                 ret == 0 && (bh != head || !block_start);
 446                 block_start = block_end, bh = next)
 447         {
 448                 next = bh->b_this_page;
 449                 block_end = block_start + blocksize;
 450                 if (block_end <= from || block_start >= to) {
 451                         if (partial && !buffer_uptodate(bh))
 452                                 *partial = 1;
 453                         continue;
 454                 }
 455                 err = (*fn)(handle, bh);
 456                 if (!ret)
 457                         ret = err;
 458         }
 459         return ret;
 460 }
 461
 462 handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
 463                                                          struct page *page,
 464                                                          unsigned from,
 465                                                          unsigned to)
 466 {
 467         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 468         handle_t *handle;
 469         int ret = 0;
 470
 471         handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
 472         if (IS_ERR(handle)) {
 473                 ret = -ENOMEM;
 474                 mlog_errno(ret);
 475                 goto out;
 476         }
 477
 478         if (ocfs2_should_order_data(inode)) {
 479                 ret = ocfs2_jbd2_file_inode(handle, inode);
 480                 if (ret < 0)
 481                         mlog_errno(ret);
 482         }
 483 out:
 484         if (ret) {
 485                 if (!IS_ERR(handle))
 486                         ocfs2_commit_trans(osb, handle);
 487                 handle = ERR_PTR(ret);
 488         }
 489         return handle;
 490 }
 491
 492 static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
 493 {
 494         sector_t status;
 495         u64 p_blkno = 0;
 496         int err = 0;
 497         struct inode *inode = mapping->host;
 498
 499         mlog_entry("(block = %llu)\n", (unsigned long long)block);
 500
 501         /* We don't need to lock journal system files, since they aren't
 502          * accessed concurrently from multiple nodes.
 503          */
 504         if (!INODE_JOURNAL(inode)) {
 505                 err = ocfs2_inode_lock(inode, NULL, 0);
 506                 if (err) {
 507                         if (err != -ENOENT)
 508                                 mlog_errno(err);
 509                         goto bail;
 510                 }
 511                 down_read(&OCFS2_I(inode)->ip_alloc_sem);
 512         }
 513
 514         if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
 515                 err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
 516                                                   NULL);
 517
 518         if (!INODE_JOURNAL(inode)) {
 519                 up_read(&OCFS2_I(inode)->ip_alloc_sem);
 520                 ocfs2_inode_unlock(inode, 0);
 521         }
 522
 523         if (err) {
 524                 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
 525                      (unsigned long long)block);
 526                 mlog_errno(err);
 527                 goto bail;
 528         }
 529
 530 bail:
 531         status = err ? 0 : p_blkno;
 532
 533         mlog_exit((int)status);
 534
 535         return status;
 536 }
 537
 538 /*
 539  * TODO: Make this into a generic get_blocks function.
 540  *
 541  * From do_direct_io in direct-io.c:
 542  *  "So what we do is to permit the ->get_blocks function to populate
 543  *   bh.b_size with the size of IO which is permitted at this offset and
 544  *   this i_blkbits."
 545  *
 546  * This function is called directly from get_more_blocks in direct-io.c.
 547  *
 548  * called like this: dio->get_blocks(dio->inode, fs_startblk,
 549  *                                      fs_count, map_bh, dio->rw == WRITE);
 550  *
 551  * Note that we never bother to allocate blocks here, and thus ignore the
 552  * create argument.
 553  */
 554 static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
 555                                      struct buffer_head *bh_result, int create)
 556 {
 557         int ret;
 558         u64 p_blkno, inode_blocks, contig_blocks;
 559         unsigned int ext_flags;
 560         unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
 561         unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
 562
 563         /* This function won't even be called if the request isn't all
 564          * nicely aligned and of the right size, so there's no need
 565          * for us to check any of that. */
 566
 567         inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 568
 569         /* This figures out the size of the next contiguous block, and
 570          * our logical offset */
 571         ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
 572                                           &contig_blocks, &ext_flags);
 573         if (ret) {
 574                 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
 575                      (unsigned long long)iblock);
 576                 ret = -EIO;
 577                 goto bail;
 578         }
 579
 580         /* We should already CoW the refcounted extent in case of create. */
 581         BUG_ON(create && (ext_flags & OCFS2_EXT_REFCOUNTED));
 582
 583         /*
 584          * get_more_blocks() expects us to describe a hole by clearing
 585          * the mapped bit on bh_result().
 586          *
 587          * Consider an unwritten extent as a hole.
 588          */
 589         if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
 590                 map_bh(bh_result, inode->i_sb, p_blkno);
 591         else
 592                 clear_buffer_mapped(bh_result);
 593
 594         /* make sure we don't map more than max_blocks blocks here as
 595            that's all the kernel will handle at this point. */
 596         if (max_blocks < contig_blocks)
 597                 contig_blocks = max_blocks;
 598         bh_result->b_size = contig_blocks << blocksize_bits;
 599 bail:
 600         return ret;
 601 }
 602
 603 /*
 604  * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
 605  * particularly interested in the aio/dio case.  Like the core uses
 606  * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
 607  * truncation on another.
 608  */
 609 static void ocfs2_dio_end_io(struct kiocb *iocb,
 610                              loff_t offset,
 611                              ssize_t bytes,
 612                              void *private)
 613 {
 614         struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
 615         int level;
 616
 617         /* this io's submitter should not have unlocked this before we could */
 618         BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
 619
 620         ocfs2_iocb_clear_rw_locked(iocb);
 621
 622         level = ocfs2_iocb_rw_locked_level(iocb);
 623         if (!level)
 624                 up_read(&inode->i_alloc_sem);
 625         ocfs2_rw_unlock(inode, level);
 626 }
 627
 628 /*
 629  * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
 630  * from ext3.  PageChecked() bits have been removed as OCFS2 does not
 631  * do journalled data.
 632  */
 633 static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
 634 {
 635         journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
 636
 637         jbd2_journal_invalidatepage(journal, page, offset);
 638 }
 639
 640 static int ocfs2_releasepage(struct page *page, gfp_t wait)
 641 {
 642         journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;
 643
 644         if (!page_has_buffers(page))
 645                 return 0;
 646         return jbd2_journal_try_to_free_buffers(journal, page, wait);
 647 }
 648
 649 static ssize_t ocfs2_direct_IO(int rw,
 650                                struct kiocb *iocb,
 651                                const struct iovec *iov,
 652                                loff_t offset,
 653                                unsigned long nr_segs)
 654 {
 655         struct file *file = iocb->ki_filp;
 656         struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
 657         int ret;
 658
 659         mlog_entry_void();
 660
 661         /*
 662          * Fallback to buffered I/O if we see an inode without
 663          * extents.
 664          */
 665         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
 666                 return 0;
 667
 668         /* Fallback to buffered I/O if we are appending. */
 669         if (i_size_read(inode) <= offset)
 670                 return 0;
 671
 672         ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
 673                                             inode->i_sb->s_bdev, iov, offset,
 674                                             nr_segs,
 675                                             ocfs2_direct_IO_get_blocks,
 676                                             ocfs2_dio_end_io);
 677
 678         mlog_exit(ret);
 679         return ret;
 680 }
 681
 682 static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
 683                                             u32 cpos,
 684                                             unsigned int *start,
 685                                             unsigned int *end)
 686 {
 687         unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;
 688
 689         if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
 690                 unsigned int cpp;
 691
 692                 cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);
 693
 694                 cluster_start = cpos % cpp;
 695                 cluster_start = cluster_start << osb->s_clustersize_bits;
 696
 697                 cluster_end = cluster_start + osb->s_clustersize;
 698         }
 699
 700         BUG_ON(cluster_start > PAGE_SIZE);
 701         BUG_ON(cluster_end > PAGE_SIZE);
 702
 703         if (start)
 704                 *start = cluster_start;
 705         if (end)
 706                 *end = cluster_end;
 707 }
 708
 709 /*
 710  * 'from' and 'to' are the region in the page to avoid zeroing.
 711  *
 712  * If pagesize > clustersize, this function will avoid zeroing outside
 713  * of the cluster boundary.
 714  *
 715  * from == to == 0 is code for "zero the entire cluster region"
 716  */
 717 static void ocfs2_clear_page_regions(struct page *page,
 718                                      struct ocfs2_super *osb, u32 cpos,
 719                                      unsigned from, unsigned to)
 720 {
 721         void *kaddr;
 722         unsigned int cluster_start, cluster_end;
 723
 724         ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);
 725
 726         kaddr = kmap_atomic(page, KM_USER0);
 727
 728         if (from || to) {
 729                 if (from > cluster_start)
 730                         memset(kaddr + cluster_start, 0, from - cluster_start);
 731                 if (to < cluster_end)
 732                         memset(kaddr + to, 0, cluster_end - to);
 733         } else {
 734                 memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
 735         }
 736
 737         kunmap_atomic(kaddr, KM_USER0);
 738 }
 739
 740 /*
 741  * Nonsparse file systems fully allocate before we get to the write
 742  * code. This prevents ocfs2_write() from tagging the write as an
 743  * allocating one, which means ocfs2_map_page_blocks() might try to
 744  * read-in the blocks at the tail of our file. Avoid reading them by
 745  * testing i_size against each block offset.
 746  */
 747 static int ocfs2_should_read_blk(struct inode *inode, struct page *page,
 748                                  unsigned int block_start)
 749 {
 750         u64 offset = page_offset(page) + block_start;
 751
 752         if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
 753                 return 1;
 754
 755         if (i_size_read(inode) > offset)
 756                 return 1;
 757
 758         return 0;
 759 }
 760
 761 /*
 762  * Some of this taken from block_prepare_write(). We already have our
 763  * mapping by now though, and the entire write will be allocating or
 764  * it won't, so not much need to use BH_New.
 765  *
 766  * This will also skip zeroing, which is handled externally.
 767  */
 768 int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
 769                           struct inode *inode, unsigned int from,
 770                           unsigned int to, int new)
 771 {
 772         int ret = 0;
 773         struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
 774         unsigned int block_end, block_start;
 775         unsigned int bsize = 1 << inode->i_blkbits;
 776
 777         if (!page_has_buffers(page))
 778                 create_empty_buffers(page, bsize, 0);
 779
 780         head = page_buffers(page);
 781         for (bh = head, block_start = 0; bh != head || !block_start;
 782              bh = bh->b_this_page, block_start += bsize) {
 783                 block_end = block_start + bsize;
 784
 785                 clear_buffer_new(bh);
 786
 787                 /*
 788                  * Ignore blocks outside of our i/o range -
 789                  * they may belong to unallocated clusters.
 790                  */
 791                 if (block_start >= to || block_end <= from) {
 792                         if (PageUptodate(page))
 793                                 set_buffer_uptodate(bh);
 794                         continue;
 795                 }
 796
 797                 /*
 798                  * For an allocating write with cluster size >= page
 799                  * size, we always write the entire page.
 800                  */
 801                 if (new)
 802                         set_buffer_new(bh);
 803
 804                 if (!buffer_mapped(bh)) {
 805                         map_bh(bh, inode->i_sb, *p_blkno);
 806                         unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
 807                 }
 808
 809                 if (PageUptodate(page)) {
 810                         if (!buffer_uptodate(bh))
 811                                 set_buffer_uptodate(bh);
 812                 } else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
 813                            !buffer_new(bh) &&
 814                            ocfs2_should_read_blk(inode, page, block_start) &&
 815                            (block_start < from || block_end > to)) {
 816                         ll_rw_block(READ, 1, &bh);
 817                         *wait_bh++=bh;
 818                 }
 819
 820                 *p_blkno = *p_blkno + 1;
 821         }
 822
 823         /*
 824          * If we issued read requests - let them complete.
 825          */
 826         while(wait_bh > wait) {
 827                 wait_on_buffer(*--wait_bh);
 828                 if (!buffer_uptodate(*wait_bh))
 829                         ret = -EIO;
 830         }
 831
 832         if (ret == 0 || !new)
 833                 return ret;
 834
 835         /*
 836          * If we get -EIO above, zero out any newly allocated blocks
 837          * to avoid exposing stale data.
 838          */
 839         bh = head;
 840         block_start = 0;
 841         do {
 842                 block_end = block_start + bsize;
 843                 if (block_end <= from)
 844                         goto next_bh;
 845                 if (block_start >= to)
 846                         break;
 847
 848                 zero_user(page, block_start, bh->b_size);
 849                 set_buffer_uptodate(bh);
 850                 mark_buffer_dirty(bh);
 851
 852 next_bh:
 853                 block_start = block_end;
 854                 bh = bh->b_this_page;
 855         } while (bh != head);
 856
 857         return ret;
 858 }
 859
 860 #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE)
 861 #define OCFS2_MAX_CTXT_PAGES    1
 862 #else
 863 #define OCFS2_MAX_CTXT_PAGES    (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE)
 864 #endif
 865
 866 #define OCFS2_MAX_CLUSTERS_PER_PAGE     (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE)
 867
 868 /*
 869  * Describe the state of a single cluster to be written to.
 870  */
 871 struct ocfs2_write_cluster_desc {
 872         u32             c_cpos;
 873         u32             c_phys;
 874         /*
 875          * Give this a unique field because c_phys eventually gets
 876          * filled.
 877          */
 878         unsigned        c_new;
 879         unsigned        c_unwritten;
 880         unsigned        c_needs_zero;
 881 };
 882
 883 struct ocfs2_write_ctxt {
 884         /* Logical cluster position / len of write */
 885         u32                             w_cpos;
 886         u32                             w_clen;
 887
 888         /* First cluster allocated in a nonsparse extend */
 889         u32                             w_first_new_cpos;
 890
 891         struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE];
 892
 893         /*
 894          * This is true if page_size > cluster_size.
 895          *
 896          * It triggers a set of special cases during write which might
 897          * have to deal with allocating writes to partial pages.
 898          */
 899         unsigned int                    w_large_pages;
 900
 901         /*
 902          * Pages involved in this write.
 903          *
 904          * w_target_page is the page being written to by the user.
 905          *
 906          * w_pages is an array of pages which always contains
 907          * w_target_page, and in the case of an allocating write with
 908          * page_size < cluster size, it will contain zero'd and mapped
 909          * pages adjacent to w_target_page which need to be written
 910          * out in so that future reads from that region will get
 911          * zero's.
 912          */
 913         struct page                     *w_pages[OCFS2_MAX_CTXT_PAGES];
 914         unsigned int                    w_num_pages;
 915         struct page                     *w_target_page;
 916
 917         /*
 918          * ocfs2_write_end() uses this to know what the real range to
 919          * write in the target should be.
 920          */
 921         unsigned int                    w_target_from;
 922         unsigned int                    w_target_to;
 923
 924         /*
 925          * We could use journal_current_handle() but this is cleaner,
 926          * IMHO -Mark
 927          */
 928         handle_t                        *w_handle;
 929
 930         struct buffer_head              *w_di_bh;
 931
 932         struct ocfs2_cached_dealloc_ctxt w_dealloc;
 933 };
 934
 935 void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages)
 936 {
 937         int i;
 938
 939         for(i = 0; i < num_pages; i++) {
 940                 if (pages[i]) {
 941                         unlock_page(pages[i]);
 942                         mark_page_accessed(pages[i]);
 943                         page_cache_release(pages[i]);
 944                 }
 945         }
 946 }
 947
 948 static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc)
 949 {
 950         ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages);
 951
 952         brelse(wc->w_di_bh);
 953         kfree(wc);
 954 }
 955
 956 static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp,
 957                                   struct ocfs2_super *osb, loff_t pos,
 958                                   unsigned len, struct buffer_head *di_bh)
 959 {
 960         u32 cend;
 961         struct ocfs2_write_ctxt *wc;
 962
 963         wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS);
 964         if (!wc)
 965                 return -ENOMEM;
 966
 967         wc->w_cpos = pos >> osb->s_clustersize_bits;
 968         wc->w_first_new_cpos = UINT_MAX;
 969         cend = (pos + len - 1) >> osb->s_clustersize_bits;
 970         wc->w_clen = cend - wc->w_cpos + 1;
 971         get_bh(di_bh);
 972         wc->w_di_bh = di_bh;
 973
 974         if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
 975                 wc->w_large_pages = 1;
 976         else
 977                 wc->w_large_pages = 0;
 978
 979         ocfs2_init_dealloc_ctxt(&wc->w_dealloc);
 980
 981         *wcp = wc;
 982
 983         return 0;
 984 }
 985
 986 /*
 987  * If a page has any new buffers, zero them out here, and mark them uptodate
 988  * and dirty so they'll be written out (in order to prevent uninitialised
 989  * block data from leaking). And clear the new bit.
 990  */
 991 static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 992 {
 993         unsigned int block_start, block_end;
 994         struct buffer_head *head, *bh;
 995
 996         BUG_ON(!PageLocked(page));
 997         if (!page_has_buffers(page))
 998                 return;
 999
1000         bh = head = page_buffers(page);
1001         block_start = 0;
1002         do {
1003                 block_end = block_start + bh->b_size;
1004
1005                 if (buffer_new(bh)) {
1006                         if (block_end > from && block_start < to) {
1007                                 if (!PageUptodate(page)) {
1008                                         unsigned start, end;
1009
1010                                         start = max(from, block_start);
1011                                         end = min(to, block_end);
1012
1013                                         zero_user_segment(page, start, end);
1014                                         set_buffer_uptodate(bh);
1015                                 }
1016
1017                                 clear_buffer_new(bh);
1018                                 mark_buffer_dirty(bh);
1019                         }
1020                 }
1021
1022                 block_start = block_end;
1023                 bh = bh->b_this_page;
1024         } while (bh != head);
1025 }
1026
1027 /*
1028  * Only called when we have a failure during allocating write to write
1029  * zero's to the newly allocated region.
1030  */
1031 static void ocfs2_write_failure(struct inode *inode,
1032                                 struct ocfs2_write_ctxt *wc,
1033                                 loff_t user_pos, unsigned user_len)
1034 {
1035         int i;
1036         unsigned from = user_pos & (PAGE_CACHE_SIZE - 1),
1037                 to = user_pos + user_len;
1038         struct page *tmppage;
1039
1040         ocfs2_zero_new_buffers(wc->w_target_page, from, to);
1041
1042         for(i = 0; i < wc->w_num_pages; i++) {
1043                 tmppage = wc->w_pages[i];
1044
1045                 if (page_has_buffers(tmppage)) {
1046                         if (ocfs2_should_order_data(inode))
1047                                 ocfs2_jbd2_file_inode(wc->w_handle, inode);
1048
1049                         block_commit_write(tmppage, from, to);
1050                 }
1051         }
1052 }
1053
1054 static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno,
1055                                         struct ocfs2_write_ctxt *wc,
1056                                         struct page *page, u32 cpos,
1057                                         loff_t user_pos, unsigned user_len,
1058                                         int new)
1059 {
1060         int ret;
1061         unsigned int map_from = 0, map_to = 0;
1062         unsigned int cluster_start, cluster_end;
1063         unsigned int user_data_from = 0, user_data_to = 0;
1064
1065         ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,
1066                                         &cluster_start, &cluster_end);
1067
1068         if (page == wc->w_target_page) {
1069                 map_from = user_pos & (PAGE_CACHE_SIZE - 1);
1070                 map_to = map_from + user_len;
1071
1072                 if (new)
1073                         ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1074                                                     cluster_start, cluster_end,
1075                                                     new);
1076                 else
1077                         ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1078                                                     map_from, map_to, new);
1079                 if (ret) {
1080                         mlog_errno(ret);
1081                         goto out;
1082                 }
1083
1084                 user_data_from = map_from;
1085                 user_data_to = map_to;
1086                 if (new) {
1087                         map_from = cluster_start;
1088                         map_to = cluster_end;
1089                 }
1090         } else {
1091                 /*
1092                  * If we haven't allocated the new page yet, we
1093                  * shouldn't be writing it out without copying user
1094                  * data. This is likely a math error from the caller.
1095                  */
1096                 BUG_ON(!new);
1097
1098                 map_from = cluster_start;
1099                 map_to = cluster_end;
1100
1101                 ret = ocfs2_map_page_blocks(page, p_blkno, inode,
1102                                             cluster_start, cluster_end, new);
1103                 if (ret) {
1104                         mlog_errno(ret);
1105                         goto out;
1106                 }
1107         }
1108
1109         /*
1110          * Parts of newly allocated pages need to be zero'd.
1111          *
1112          * Above, we have also rewritten 'to' and 'from' - as far as
1113          * the rest of the function is concerned, the entire cluster
1114          * range inside of a page needs to be written.
1115          *
1116          * We can skip this if the page is up to date - it's already
1117          * been zero'd from being read in as a hole.
1118          */
1119         if (new && !PageUptodate(page))
1120                 ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
1121                                          cpos, user_data_from, user_data_to);
1122
1123         flush_dcache_page(page);
1124
1125 out:
1126         return ret;
1127 }
1128
1129 /*
1130  * This function will only grab one clusters worth of pages.
1131  */
1132 static int ocfs2_grab_pages_for_write(struct address_space *mapping,
1133                                       struct ocfs2_write_ctxt *wc,
1134                                       u32 cpos, loff_t user_pos, int new,
1135                                       struct page *mmap_page)
1136 {
1137         int ret = 0, i;
1138         unsigned long start, target_index, index;
1139         struct inode *inode = mapping->host;
1140
1141         target_index = user_pos >> PAGE_CACHE_SHIFT;
1142
1143         /*
1144          * Figure out how many pages we'll be manipulating here. For
1145          * non allocating write, we just change the one
1146          * page. Otherwise, we'll need a whole clusters worth.
1147          */
1148         if (new) {
1149                 wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb);
1150                 start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos);
1151         } else {
1152                 wc->w_num_pages = 1;
1153                 start = target_index;
1154         }
1155
1156         for(i = 0; i < wc->w_num_pages; i++) {
1157                 index = start + i;
1158
1159                 if (index == target_index && mmap_page) {
1160                         /*
1161                          * ocfs2_pagemkwrite() is a little different
1162                          * and wants us to directly use the page
1163                          * passed in.
1164                          */
1165                         lock_page(mmap_page);
1166
1167                         if (mmap_page->mapping != mapping) {
1168                                 unlock_page(mmap_page);
1169                                 /*
1170                                  * Sanity check - the locking in
1171                                  * ocfs2_pagemkwrite() should ensure
1172                                  * that this code doesn't trigger.
1173                                  */
1174                                 ret = -EINVAL;
1175                                 mlog_errno(ret);
1176                                 goto out;
1177                         }
1178
1179                         page_cache_get(mmap_page);
1180                         wc->w_pages[i] = mmap_page;
1181                 } else {
1182                         wc->w_pages[i] = find_or_create_page(mapping, index,
1183                                                              GFP_NOFS);
1184                         if (!wc->w_pages[i]) {
1185                                 ret = -ENOMEM;
1186                                 mlog_errno(ret);
1187                                 goto out;
1188                         }
1189                 }
1190
1191                 if (index == target_index)
1192                         wc->w_target_page = wc->w_pages[i];
1193         }
1194 out:
1195         return ret;
1196 }
1197
1198 /*
1199  * Prepare a single cluster for write one cluster into the file.
1200  */
1201 static int ocfs2_write_cluster(struct address_space *mapping,
1202                                u32 phys, unsigned int unwritten,
1203                                unsigned int should_zero,
1204                                struct ocfs2_alloc_context *data_ac,
1205                                struct ocfs2_alloc_context *meta_ac,
1206                                struct ocfs2_write_ctxt *wc, u32 cpos,
1207                                loff_t user_pos, unsigned user_len)
1208 {
1209         int ret, i, new;
1210         u64 v_blkno, p_blkno;
1211         struct inode *inode = mapping->host;
1212         struct ocfs2_extent_tree et;
1213
1214         new = phys == 0 ? 1 : 0;
1215         if (new) {
1216                 u32 tmp_pos;
1217
1218                 /*
1219                  * This is safe to call with the page locks - it won't take
1220                  * any additional semaphores or cluster locks.
1221                  */
1222                 tmp_pos = cpos;
1223                 ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode,
1224                                            &tmp_pos, 1, 0, wc->w_di_bh,
1225                                            wc->w_handle, data_ac,
1226                                            meta_ac, NULL);
1227                 /*
1228                  * This shouldn't happen because we must have already
1229                  * calculated the correct meta data allocation required. The
1230                  * internal tree allocation code should know how to increase
1231                  * transaction credits itself.
1232                  *
1233                  * If need be, we could handle -EAGAIN for a
1234                  * RESTART_TRANS here.
1235                  */
1236                 mlog_bug_on_msg(ret == -EAGAIN,
1237                                 "Inode %llu: EAGAIN return during allocation.\n",
1238                                 (unsigned long long)OCFS2_I(inode)->ip_blkno);
1239                 if (ret < 0) {
1240                         mlog_errno(ret);
1241                         goto out;
1242                 }
1243         } else if (unwritten) {
1244                 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1245                                               wc->w_di_bh);
1246                 ret = ocfs2_mark_extent_written(inode, &et,
1247                                                 wc->w_handle, cpos, 1, phys,
1248                                                 meta_ac, &wc->w_dealloc);
1249                 if (ret < 0) {
1250                         mlog_errno(ret);
1251                         goto out;
1252                 }
1253         }
1254
1255         if (should_zero)
1256                 v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos);
1257         else
1258                 v_blkno = user_pos >> inode->i_sb->s_blocksize_bits;
1259
1260         /*
1261          * The only reason this should fail is due to an inability to
1262          * find the extent added.
1263          */
1264         ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
1265                                           NULL);
1266         if (ret < 0) {
1267                 ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, "
1268                             "at logical block %llu",
1269                             (unsigned long long)OCFS2_I(inode)->ip_blkno,
1270                             (unsigned long long)v_blkno);
1271                 goto out;
1272         }
1273
1274         BUG_ON(p_blkno == 0);
1275
1276         for(i = 0; i < wc->w_num_pages; i++) {
1277                 int tmpret;
1278
1279                 tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc,
1280                                                       wc->w_pages[i], cpos,
1281                                                       user_pos, user_len,
1282                                                       should_zero);
1283                 if (tmpret) {
1284                         mlog_errno(tmpret);
1285                         if (ret == 0)
1286                                 ret = tmpret;
1287                 }
1288         }
1289
1290         /*
1291          * We only have cleanup to do in case of allocating write.
1292          */
1293         if (ret && new)
1294                 ocfs2_write_failure(inode, wc, user_pos, user_len);
1295
1296 out:
1297
1298         return ret;
1299 }
1300
1301 static int ocfs2_write_cluster_by_desc(struct address_space *mapping,
1302                                        struct ocfs2_alloc_context *data_ac,
1303                                        struct ocfs2_alloc_context *meta_ac,
1304                                        struct ocfs2_write_ctxt *wc,
1305                                        loff_t pos, unsigned len)
1306 {
1307         int ret, i;
1308         loff_t cluster_off;
1309         unsigned int local_len = len;
1310         struct ocfs2_write_cluster_desc *desc;
1311         struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb);
1312
1313         for (i = 0; i < wc->w_clen; i++) {
1314                 desc = &wc->w_desc[i];
1315
1316                 /*
1317                  * We have to make sure that the total write passed in
1318                  * doesn't extend past a single cluster.
1319                  */
1320                 local_len = len;
1321                 cluster_off = pos & (osb->s_clustersize - 1);
1322                 if ((cluster_off + local_len) > osb->s_clustersize)
1323                         local_len = osb->s_clustersize - cluster_off;
1324
1325                 ret = ocfs2_write_cluster(mapping, desc->c_phys,
1326                                           desc->c_unwritten,
1327                                           desc->c_needs_zero,
1328                                           data_ac, meta_ac,
1329                                           wc, desc->c_cpos, pos, local_len);
1330                 if (ret) {
1331                         mlog_errno(ret);
1332                         goto out;
1333                 }
1334
1335                 len -= local_len;
1336                 pos += local_len;
1337         }
1338
1339         ret = 0;
1340 out:
1341         return ret;
1342 }
1343
1344 /*
1345  * ocfs2_write_end() wants to know which parts of the target page it
1346  * should complete the write on. It's easiest to compute them ahead of
1347  * time when a more complete view of the write is available.
1348  */
1349 static void ocfs2_set_target_boundaries(struct ocfs2_super *osb,
1350                                         struct ocfs2_write_ctxt *wc,
1351                                         loff_t pos, unsigned len, int alloc)
1352 {
1353         struct ocfs2_write_cluster_desc *desc;
1354
1355         wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1);
1356         wc->w_target_to = wc->w_target_from + len;
1357
1358         if (alloc == 0)
1359                 return;
1360
1361         /*
1362          * Allocating write - we may have different boundaries based
1363          * on page size and cluster size.
1364          *
1365          * NOTE: We can no longer compute one value from the other as
1366          * the actual write length and user provided length may be
1367          * different.
1368          */
1369
1370         if (wc->w_large_pages) {
1371                 /*
1372                  * We only care about the 1st and last cluster within
1373                  * our range and whether they should be zero'd or not. Either
1374                  * value may be extended out to the start/end of a
1375                  * newly allocated cluster.
1376                  */
1377                 desc = &wc->w_desc[0];
1378                 if (desc->c_needs_zero)
1379                         ocfs2_figure_cluster_boundaries(osb,
1380                                                         desc->c_cpos,
1381                                                         &wc->w_target_from,
1382                                                         NULL);
1383
1384                 desc = &wc->w_desc[wc->w_clen - 1];
1385                 if (desc->c_needs_zero)
1386                         ocfs2_figure_cluster_boundaries(osb,
1387                                                         desc->c_cpos,
1388                                                         NULL,
1389                                                         &wc->w_target_to);
1390         } else {
1391                 wc->w_target_from = 0;
1392                 wc->w_target_to = PAGE_CACHE_SIZE;
1393         }
1394 }
1395
1396 /*
1397  * Populate each single-cluster write descriptor in the write context
1398  * with information about the i/o to be done.
1399  *
1400  * Returns the number of clusters that will have to be allocated, as
1401  * well as a worst case estimate of the number of extent records that
1402  * would have to be created during a write to an unwritten region.
1403  */
1404 static int ocfs2_populate_write_desc(struct inode *inode,
1405                                      struct ocfs2_write_ctxt *wc,
1406                                      unsigned int *clusters_to_alloc,
1407                                      unsigned int *extents_to_split)
1408 {
1409         int ret;
1410         struct ocfs2_write_cluster_desc *desc;
1411         unsigned int num_clusters = 0;
1412         unsigned int ext_flags = 0;
1413         u32 phys = 0;
1414         int i;
1415
1416         *clusters_to_alloc = 0;
1417         *extents_to_split = 0;
1418
1419         for (i = 0; i < wc->w_clen; i++) {
1420                 desc = &wc->w_desc[i];
1421                 desc->c_cpos = wc->w_cpos + i;
1422
1423                 if (num_clusters == 0) {
1424                         /*
1425                          * Need to look up the next extent record.
1426                          */
1427                         ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys,
1428                                                  &num_clusters, &ext_flags);
1429                         if (ret) {
1430                                 mlog_errno(ret);
1431                                 goto out;
1432                         }
1433
1434                         /* We should already CoW the refcountd extent. */
1435                         BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED);
1436
1437                         /*
1438                          * Assume worst case - that we're writing in
1439                          * the middle of the extent.
1440                          *
1441                          * We can assume that the write proceeds from
1442                          * left to right, in which case the extent
1443                          * insert code is smart enough to coalesce the
1444                          * next splits into the previous records created.
1445                          */
1446                         if (ext_flags & OCFS2_EXT_UNWRITTEN)
1447                                 *extents_to_split = *extents_to_split + 2;
1448                 } else if (phys) {
1449                         /*
1450                          * Only increment phys if it doesn't describe
1451                          * a hole.
1452                          */
1453                         phys++;
1454                 }
1455
1456                 /*
1457                  * If w_first_new_cpos is < UINT_MAX, we have a non-sparse
1458                  * file that got extended.  w_first_new_cpos tells us
1459                  * where the newly allocated clusters are so we can
1460                  * zero them.
1461                  */
1462                 if (desc->c_cpos >= wc->w_first_new_cpos) {
1463                         BUG_ON(phys == 0);
1464                         desc->c_needs_zero = 1;
1465                 }
1466
1467                 desc->c_phys = phys;
1468                 if (phys == 0) {
1469                         desc->c_new = 1;
1470                         desc->c_needs_zero = 1;
1471                         *clusters_to_alloc = *clusters_to_alloc + 1;
1472                 }
1473
1474                 if (ext_flags & OCFS2_EXT_UNWRITTEN) {
1475                         desc->c_unwritten = 1;
1476                         desc->c_needs_zero = 1;
1477                 }
1478
1479                 num_clusters--;
1480         }
1481
1482         ret = 0;
1483 out:
1484         return ret;
1485 }
1486
1487 static int ocfs2_write_begin_inline(struct address_space *mapping,
1488                                     struct inode *inode,
1489                                     struct ocfs2_write_ctxt *wc)
1490 {
1491         int ret;
1492         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1493         struct page *page;
1494         handle_t *handle;
1495         struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1496
1497         page = find_or_create_page(mapping, 0, GFP_NOFS);
1498         if (!page) {
1499                 ret = -ENOMEM;
1500                 mlog_errno(ret);
1501                 goto out;
1502         }
1503         /*
1504          * If we don't set w_num_pages then this page won't get unlocked
1505          * and freed on cleanup of the write context.
1506          */
1507         wc->w_pages[0] = wc->w_target_page = page;
1508         wc->w_num_pages = 1;
1509
1510         handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1511         if (IS_ERR(handle)) {
1512                 ret = PTR_ERR(handle);
1513                 mlog_errno(ret);
1514                 goto out;
1515         }
1516
1517         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1518                                       OCFS2_JOURNAL_ACCESS_WRITE);
1519         if (ret) {
1520                 ocfs2_commit_trans(osb, handle);
1521
1522                 mlog_errno(ret);
1523                 goto out;
1524         }
1525
1526         if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL))
1527                 ocfs2_set_inode_data_inline(inode, di);
1528
1529         if (!PageUptodate(page)) {
1530                 ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh);
1531                 if (ret) {
1532                         ocfs2_commit_trans(osb, handle);
1533
1534                         goto out;
1535                 }
1536         }
1537
1538         wc->w_handle = handle;
1539 out:
1540         return ret;
1541 }
1542
1543 int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size)
1544 {
1545         struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
1546
1547         if (new_size <= le16_to_cpu(di->id2.i_data.id_count))
1548                 return 1;
1549         return 0;
1550 }
1551
1552 static int ocfs2_try_to_write_inline_data(struct address_space *mapping,
1553                                           struct inode *inode, loff_t pos,
1554                                           unsigned len, struct page *mmap_page,
1555                                           struct ocfs2_write_ctxt *wc)
1556 {
1557         int ret, written = 0;
1558         loff_t end = pos + len;
1559         struct ocfs2_inode_info *oi = OCFS2_I(inode);
1560         struct ocfs2_dinode *di = NULL;
1561
1562         mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n",
1563              (unsigned long long)oi->ip_blkno, len, (unsigned long long)pos,
1564              oi->ip_dyn_features);
1565
1566         /*
1567          * Handle inodes which already have inline data 1st.
1568          */
1569         if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1570                 if (mmap_page == NULL &&
1571                     ocfs2_size_fits_inline_data(wc->w_di_bh, end))
1572                         goto do_inline_write;
1573
1574                 /*
1575                  * The write won't fit - we have to give this inode an
1576                  * inline extent list now.
1577                  */
1578                 ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh);
1579                 if (ret)
1580                         mlog_errno(ret);
1581                 goto out;
1582         }
1583
1584         /*
1585          * Check whether the inode can accept inline data.
1586          */
1587         if (oi->ip_clusters != 0 || i_size_read(inode) != 0)
1588                 return 0;
1589
1590         /*
1591          * Check whether the write can fit.
1592          */
1593         di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1594         if (mmap_page ||
1595             end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di))
1596                 return 0;
1597
1598 do_inline_write:
1599         ret = ocfs2_write_begin_inline(mapping, inode, wc);
1600         if (ret) {
1601                 mlog_errno(ret);
1602                 goto out;
1603         }
1604
1605         /*
1606          * This signals to the caller that the data can be written
1607          * inline.
1608          */
1609         written = 1;
1610 out:
1611         return written ? written : ret;
1612 }
1613
1614 /*
1615  * This function only does anything for file systems which can't
1616  * handle sparse files.
1617  *
1618  * What we want to do here is fill in any hole between the current end
1619  * of allocation and the end of our write. That way the rest of the
1620  * write path can treat it as an non-allocating write, which has no
1621  * special case code for sparse/nonsparse files.
1622  */
1623 static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos,
1624                                         unsigned len,
1625                                         struct ocfs2_write_ctxt *wc)
1626 {
1627         int ret;
1628         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1629         loff_t newsize = pos + len;
1630
1631         if (ocfs2_sparse_alloc(osb))
1632                 return 0;
1633
1634         if (newsize <= i_size_read(inode))
1635                 return 0;
1636
1637         ret = ocfs2_extend_no_holes(inode, newsize, pos);
1638         if (ret)
1639                 mlog_errno(ret);
1640
1641         wc->w_first_new_cpos =
1642                 ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode));
1643
1644         return ret;
1645 }
1646
1647 int ocfs2_write_begin_nolock(struct address_space *mapping,
1648                              loff_t pos, unsigned len, unsigned flags,
1649                              struct page **pagep, void **fsdata,
1650                              struct buffer_head *di_bh, struct page *mmap_page)
1651 {
1652         int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
1653         unsigned int clusters_to_alloc, extents_to_split;
1654         struct ocfs2_write_ctxt *wc;
1655         struct inode *inode = mapping->host;
1656         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1657         struct ocfs2_dinode *di;
1658         struct ocfs2_alloc_context *data_ac = NULL;
1659         struct ocfs2_alloc_context *meta_ac = NULL;
1660         handle_t *handle;
1661         struct ocfs2_extent_tree et;
1662
1663         ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
1664         if (ret) {
1665                 mlog_errno(ret);
1666                 return ret;
1667         }
1668
1669         if (ocfs2_supports_inline_data(osb)) {
1670                 ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len,
1671                                                      mmap_page, wc);
1672                 if (ret == 1) {
1673                         ret = 0;
1674                         goto success;
1675                 }
1676                 if (ret < 0) {
1677                         mlog_errno(ret);
1678                         goto out;
1679                 }
1680         }
1681
1682         ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc);
1683         if (ret) {
1684                 mlog_errno(ret);
1685                 goto out;
1686         }
1687
1688         ret = ocfs2_check_range_for_refcount(inode, pos, len);
1689         if (ret < 0) {
1690                 mlog_errno(ret);
1691                 goto out;
1692         } else if (ret == 1) {
1693                 ret = ocfs2_refcount_cow(inode, di_bh,
1694                                          wc->w_cpos, wc->w_clen, UINT_MAX);
1695                 if (ret) {
1696                         mlog_errno(ret);
1697                         goto out;
1698                 }
1699         }
1700
1701         ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc,
1702                                         &extents_to_split);
1703         if (ret) {
1704                 mlog_errno(ret);
1705                 goto out;
1706         }
1707
1708         di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1709
1710         /*
1711          * We set w_target_from, w_target_to here so that
1712          * ocfs2_write_end() knows which range in the target page to
1713          * write out. An allocation requires that we write the entire
1714          * cluster range.
1715          */
1716         if (clusters_to_alloc || extents_to_split) {
1717                 /*
1718                  * XXX: We are stretching the limits of
1719                  * ocfs2_lock_allocators(). It greatly over-estimates
1720                  * the work to be done.
1721                  */
1722                 mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u,"
1723                      " clusters_to_add = %u, extents_to_split = %u\n",
1724                      (unsigned long long)OCFS2_I(inode)->ip_blkno,
1725                      (long long)i_size_read(inode), le32_to_cpu(di->i_clusters),
1726                      clusters_to_alloc, extents_to_split);
1727
1728                 ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode),
1729                                               wc->w_di_bh);
1730                 ret = ocfs2_lock_allocators(inode, &et,
1731                                             clusters_to_alloc, extents_to_split,
1732                                             &data_ac, &meta_ac);
1733                 if (ret) {
1734                         mlog_errno(ret);
1735                         goto out;
1736                 }
1737
1738                 credits = ocfs2_calc_extend_credits(inode->i_sb,
1739                                                     &di->id2.i_list,
1740                                                     clusters_to_alloc);
1741
1742         }
1743
1744         /*
1745          * We have to zero sparse allocated clusters, unwritten extent clusters,
1746          * and non-sparse clusters we just extended.  For non-sparse writes,
1747          * we know zeros will only be needed in the first and/or last cluster.
1748          */
1749         if (clusters_to_alloc || extents_to_split ||
1750             (wc->w_clen && (wc->w_desc[0].c_needs_zero ||
1751                             wc->w_desc[wc->w_clen - 1].c_needs_zero)))
1752                 cluster_of_pages = 1;
1753         else
1754                 cluster_of_pages = 0;
1755
1756         ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages);
1757
1758         handle = ocfs2_start_trans(osb, credits);
1759         if (IS_ERR(handle)) {
1760                 ret = PTR_ERR(handle);
1761                 mlog_errno(ret);
1762                 goto out;
1763         }
1764
1765         wc->w_handle = handle;
1766
1767         if (clusters_to_alloc) {
1768                 ret = dquot_alloc_space_nodirty(inode,
1769                         ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1770                 if (ret)
1771                         goto out_commit;
1772         }
1773         /*
1774          * We don't want this to fail in ocfs2_write_end(), so do it
1775          * here.
1776          */
1777         ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh,
1778                                       OCFS2_JOURNAL_ACCESS_WRITE);
1779         if (ret) {
1780                 mlog_errno(ret);
1781                 goto out_quota;
1782         }
1783
1784         /*
1785          * Fill our page array first. That way we've grabbed enough so
1786          * that we can zero and flush if we error after adding the
1787          * extent.
1788          */
1789         ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos,
1790                                          cluster_of_pages, mmap_page);
1791         if (ret) {
1792                 mlog_errno(ret);
1793                 goto out_quota;
1794         }
1795
1796         ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos,
1797                                           len);
1798         if (ret) {
1799                 mlog_errno(ret);
1800                 goto out_quota;
1801         }
1802
1803         if (data_ac)
1804                 ocfs2_free_alloc_context(data_ac);
1805         if (meta_ac)
1806                 ocfs2_free_alloc_context(meta_ac);
1807
1808 success:
1809         *pagep = wc->w_target_page;
1810         *fsdata = wc;
1811         return 0;
1812 out_quota:
1813         if (clusters_to_alloc)
1814                 dquot_free_space(inode,
1815                           ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc));
1816 out_commit:
1817         ocfs2_commit_trans(osb, handle);
1818
1819 out:
1820         ocfs2_free_write_ctxt(wc);
1821
1822         if (data_ac)
1823                 ocfs2_free_alloc_context(data_ac);
1824         if (meta_ac)
1825                 ocfs2_free_alloc_context(meta_ac);
1826         return ret;
1827 }
1828
1829 static int ocfs2_write_begin(struct file *file, struct address_space *mapping,
1830                              loff_t pos, unsigned len, unsigned flags,
1831                              struct page **pagep, void **fsdata)
1832 {
1833         int ret;
1834         struct buffer_head *di_bh = NULL;
1835         struct inode *inode = mapping->host;
1836
1837         ret = ocfs2_inode_lock(inode, &di_bh, 1);
1838         if (ret) {
1839                 mlog_errno(ret);
1840                 return ret;
1841         }
1842
1843         /*
1844          * Take alloc sem here to prevent concurrent lookups. That way
1845          * the mapping, zeroing and tree manipulation within
1846          * ocfs2_write() will be safe against ->readpage(). This
1847          * should also serve to lock out allocation from a shared
1848          * writeable region.
1849          */
1850         down_write(&OCFS2_I(inode)->ip_alloc_sem);
1851
1852         ret = ocfs2_write_begin_nolock(mapping, pos, len, flags, pagep,
1853                                        fsdata, di_bh, NULL);
1854         if (ret) {
1855                 mlog_errno(ret);
1856                 goto out_fail;
1857         }
1858
1859         brelse(di_bh);
1860
1861         return 0;
1862
1863 out_fail:
1864         up_write(&OCFS2_I(inode)->ip_alloc_sem);
1865
1866         brelse(di_bh);
1867         ocfs2_inode_unlock(inode, 1);
1868
1869         return ret;
1870 }
1871
1872 static void ocfs2_write_end_inline(struct inode *inode, loff_t pos,
1873                                    unsigned len, unsigned *copied,
1874                                    struct ocfs2_dinode *di,
1875                                    struct ocfs2_write_ctxt *wc)
1876 {
1877         void *kaddr;
1878
1879         if (unlikely(*copied < len)) {
1880                 if (!PageUptodate(wc->w_target_page)) {
1881                         *copied = 0;
1882                         return;
1883                 }
1884         }
1885
1886         kaddr = kmap_atomic(wc->w_target_page, KM_USER0);
1887         memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied);
1888         kunmap_atomic(kaddr, KM_USER0);
1889
1890         mlog(0, "Data written to inode at offset %llu. "
1891              "id_count = %u, copied = %u, i_dyn_features = 0x%x\n",
1892              (unsigned long long)pos, *copied,
1893              le16_to_cpu(di->id2.i_data.id_count),
1894              le16_to_cpu(di->i_dyn_features));
1895 }
1896
1897 int ocfs2_write_end_nolock(struct address_space *mapping,
1898                            loff_t pos, unsigned len, unsigned copied,
1899                            struct page *page, void *fsdata)
1900 {
1901         int i;
1902         unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1);
1903         struct inode *inode = mapping->host;
1904         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1905         struct ocfs2_write_ctxt *wc = fsdata;
1906         struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
1907         handle_t *handle = wc->w_handle;
1908         struct page *tmppage;
1909
1910         if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
1911                 ocfs2_write_end_inline(inode, pos, len, &copied, di, wc);
1912                 goto out_write_size;
1913         }
1914
1915         if (unlikely(copied < len)) {
1916                 if (!PageUptodate(wc->w_target_page))
1917                         copied = 0;
1918
1919                 ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
1920                                        start+len);
1921         }
1922         flush_dcache_page(wc->w_target_page);
1923
1924         for(i = 0; i < wc->w_num_pages; i++) {
1925                 tmppage = wc->w_pages[i];
1926
1927                 if (tmppage == wc->w_target_page) {
1928                         from = wc->w_target_from;
1929                         to = wc->w_target_to;
1930
1931                         BUG_ON(from > PAGE_CACHE_SIZE ||
1932                                to > PAGE_CACHE_SIZE ||
1933                                to < from);
1934                 } else {
1935                         /*
1936                          * Pages adjacent to the target (if any) imply
1937                          * a hole-filling write in which case we want
1938                          * to flush their entire range.
1939                          */
1940                         from = 0;
1941                         to = PAGE_CACHE_SIZE;
1942                 }
1943
1944                 if (page_has_buffers(tmppage)) {
1945                         if (ocfs2_should_order_data(inode))
1946                                 ocfs2_jbd2_file_inode(wc->w_handle, inode);
1947                         block_commit_write(tmppage, from, to);
1948                 }
1949         }
1950
1951 out_write_size:
1952         pos += copied;
1953         if (pos > inode->i_size) {
1954                 i_size_write(inode, pos);
1955                 mark_inode_dirty(inode);
1956         }
1957         inode->i_blocks = ocfs2_inode_sector_count(inode);
1958         di->i_size = cpu_to_le64((u64)i_size_read(inode));
1959         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
1960         di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
1961         di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
1962         ocfs2_journal_dirty(handle, wc->w_di_bh);
1963
1964         ocfs2_commit_trans(osb, handle);
1965
1966         ocfs2_run_deallocs(osb, &wc->w_dealloc);
1967
1968         ocfs2_free_write_ctxt(wc);
1969
1970         return copied;
1971 }
1972
1973 static int ocfs2_write_end(struct file *file, struct address_space *mapping,
1974                            loff_t pos, unsigned len, unsigned copied,
1975                            struct page *page, void *fsdata)
1976 {
1977         int ret;
1978         struct inode *inode = mapping->host;
1979
1980         ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata);
1981
1982         up_write(&OCFS2_I(inode)->ip_alloc_sem);
1983         ocfs2_inode_unlock(inode, 1);
1984
1985         return ret;
1986 }
1987
1988 const struct address_space_operations ocfs2_aops = {
1989         .readpage               = ocfs2_readpage,
1990         .readpages              = ocfs2_readpages,
1991         .writepage              = ocfs2_writepage,
1992         .write_begin            = ocfs2_write_begin,
1993         .write_end              = ocfs2_write_end,
1994         .bmap                   = ocfs2_bmap,
1995         .sync_page              = block_sync_page,
1996         .direct_IO              = ocfs2_direct_IO,
1997         .invalidatepage         = ocfs2_invalidatepage,
1998         .releasepage            = ocfs2_releasepage,
1999         .migratepage            = buffer_migrate_page,
2000         .is_partially_uptodate  = block_is_partially_uptodate,
2001         .error_remove_page      = generic_error_remove_page,
2002 };