aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ocfs2/aops.c
blob: f1d1c342ce010a63cabbced4eac868bc134f08f9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <asm/byteorder.h>

#define MLOG_MASK_PREFIX ML_FILE_IO
#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "aops.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
#include "super.h"
#include "symlink.h"

#include "buffer_head_io.h"

static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
				   struct buffer_head *bh_result, int create)
{
	int err = -EIO;
	int status;
	struct ocfs2_dinode *fe = NULL;
	struct buffer_head *bh = NULL;
	struct buffer_head *buffer_cache_bh = NULL;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	void *kaddr;

	mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
		   (unsigned long long)iblock, bh_result, create);

	BUG_ON(ocfs2_inode_is_fast_symlink(inode));

	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
		     (unsigned long long)iblock);
		goto bail;
	}

	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
				  OCFS2_I(inode)->ip_blkno,
				  &bh, OCFS2_BH_CACHED, inode);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}
	fe = (struct ocfs2_dinode *) bh->b_data;

	if (!OCFS2_IS_VALID_DINODE(fe)) {
		mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
		     (unsigned long long)fe->i_blkno, 7, fe->i_signature);
		goto bail;
	}

	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
						    le32_to_cpu(fe->i_clusters))) {
		mlog(ML_ERROR, "block offset is outside the allocated size: "
		     "%llu\n", (unsigned long long)iblock);
		goto bail;
	}

	/* We don't use the page cache to create symlink data, so if
	 * need be, copy it over from the buffer cache. */
	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
			    iblock;
		buffer_cache_bh = sb_getblk(osb->sb, blkno);
		if (!buffer_cache_bh) {
			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
			goto bail;
		}

		/* we haven't locked out transactions, so a commit
		 * could've happened. Since we've got a reference on
		 * the bh, even if it commits while we're doing the
		 * copy, the data is still good. */
		if (buffer_jbd(buffer_cache_bh)
		    && ocfs2_inode_is_new(inode)) {
			kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
			if (!kaddr) {
				mlog(ML_ERROR, "couldn't kmap!\n");
				goto bail;
			}
			memcpy(kaddr + (bh_result->b_size * iblock),
			       buffer_cache_bh->b_data,
			       bh_result->b_size);
			kunmap_atomic(kaddr, KM_USER0);
			set_buffer_uptodate(bh_result);
		}
		brelse(buffer_cache_bh);
	}

	map_bh(bh_result, inode->i_sb,
	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);

	err = 0;

bail:
	if (bh)
		brelse(bh);

	mlog_exit(err);
	return err;
}

static int ocfs2_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *bh_result, int create)
{
	int err = 0;
	u64 p_blkno, past_eof;

	mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
		   (unsigned long long)iblock, bh_result, create);

	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
		     inode, inode->i_ino);

	if (S_ISLNK(inode->i_mode)) {
		/* this always does I/O for some reason. */
		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
		goto bail;
	}

	/* this can happen if another node truncs after our extend! */
	spin_lock(&OCFS2_I(inode)->ip_lock);
	if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
					       OCFS2_I(inode)->ip_clusters))
		err = -EIO;
	spin_unlock(&OCFS2_I(inode)->ip_lock);
	if (err)
		goto bail;

	err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
					  NULL);
	if (err) {
		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
		     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
		     (unsigned long long)p_blkno);
		goto bail;
	}

	map_bh(bh_result, inode->i_sb, p_blkno);

	if (bh_result->b_blocknr == 0) {
		err = -EIO;
		mlog(ML_ERROR, "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
		     (unsigned long long)iblock,
		     (unsigned long long)p_blkno,
		     (unsigned long long)OCFS2_I(inode)->ip_blkno);
	}

	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
	mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
	     (unsigned long long)past_eof);

	if (create && (iblock >= past_eof))
		set_buffer_new(bh_result);

bail:
	if (err < 0)
		err = -EIO;

	mlog_exit(err);
	return err;
}

static int ocfs2_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
	int ret, unlock = 1;

	mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));

	ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
	if (ret != 0) {
		if (ret == AOP_TRUNCATED_PAGE)
			unlock = 0;
		mlog_errno(ret);
		goto out;
	}

	down_read(&OCFS2_I(inode)->ip_alloc_sem);

	/*
	 * i_size might have just been updated as we grabed the meta lock.  We
	 * might now be discovering a truncate that hit on another node.
	 * block_read_full_page->get_block freaks out if it is asked to read
	 * beyond the end of a file, so we check here.  Callers
	 * (generic_file_read, fault->nopage) are clever enough to check i_size
	 * and notice that the page they just read isn't needed.
	 *
	 * XXX sys_readahead() seems to get that wrong?
	 */
	if (start >= i_size_read(inode)) {
		char *addr = kmap(page);
		memset(addr, 0, PAGE_SIZE);
		flush_dcache_page(page);
		kunmap(page);
		SetPageUptodate(page);
		ret = 0;
		goto out_alloc;
	}

	ret = ocfs2_data_lock_with_page(inode, 0, page);
	if (ret != 0) {
		if (ret == AOP_TRUNCATED_PAGE)
			unlock = 0;
		mlog_errno(ret);
		goto out_alloc;
	}

	ret = block_read_full_page(page, ocfs2_get_block);
	unlock = 0;

	ocfs2_data_unlock(inode, 0);
out_alloc:
	up_read(&OCFS2_I(inode)->ip_alloc_sem);
	ocfs2_meta_unlock(inode, 0);
out:
	if (unlock)
		unlock_page(page);
	mlog_exit(ret);
	return ret;
}

/* Note: Because we don't support holes, our allocation has
 * already happened (allocation writes zeros to the file data)
 * so we don't have to worry about ordered writes in
 * ocfs2_writepage.
 *
 * ->writepage is called during the process of invalidating the page cache
 * during blocked lock processing.  It can't block on any cluster locks
 * to during block mapping.  It's relying on the fact that the block
 * mapping can't have disappeared under the dirty pages that it is
 * being asked to write back.
 */
static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
{
	int ret;

	mlog_entry("(0x%p)\n", page);

	ret = block_write_full_page(page, ocfs2_get_block, wbc);

	mlog_exit(ret);

	return ret;
}

/* This can also be called from ocfs2_write_zero_page() which has done
 * it's own cluster locking. */
int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
			       unsigned from, unsigned to)
{
	int ret;

	down_read(&OCFS2_I(inode)->ip_alloc_sem);

	ret = block_prepare_write(page, from, to, ocfs2_get_block);

	up_read(&OCFS2_I(inode)->ip_alloc_sem);

	return ret;
}

/*
 * ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called
 * from loopback.  It must be able to perform its own locking around
 * ocfs2_get_block().
 */
static int ocfs2_prepare_write(struct file *file, struct page *page,
			       unsigned from, unsigned to)
{
	struct inode *inode = page->mapping->host;
	int ret;

	mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);

	ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
	if (ret != 0) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_prepare_write_nolock(inode, page, from, to);

	ocfs2_meta_unlock(inode, 0);
out:
	mlog_exit(ret);
	return ret;
}

/* Taken from ext3. We don't necessarily need the full blown
 * functionality yet, but IMHO it's better to cut and paste the whole
 * thing so we can avoid introducing our own bugs (and easily pick up
 * their fixes when they happen) --Mark */
static int walk_page_buffers(	handle_t *handle,
				struct buffer_head *head,
				unsigned from,
				unsigned to,
				int *partial,
				int (*fn)(	handle_t *handle,
						struct buffer_head *bh))
{
	struct buffer_head *bh;
	unsigned block_start, block_end;
	unsigned blocksize = head->b_size;
	int err, ret = 0;
	struct buffer_head *next;

	for (	bh = head, block_start = 0;
		ret == 0 && (bh != head || !block_start);
	    	block_start = block_end, bh = next)
	{
		next = bh->b_this_page;
		block_end = block_start + blocksize;
		if (block_end <= from || block_start >= to) {
			if (partial && !buffer_uptodate(bh))
				*partial = 1;
			continue;
		}
		err = (*fn)(handle, bh);
		if (!ret)
			ret = err;
	}
	return ret;
}

struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
							 struct page *page,
							 unsigned from,
							 unsigned to)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct ocfs2_journal_handle *handle = NULL;
	int ret = 0;

	handle = ocfs2_start_trans(osb, NULL, OCFS2_INODE_UPDATE_CREDITS);
	if (!handle) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	if (ocfs2_should_order_data(inode)) {
		ret = walk_page_buffers(handle->k_handle,
					page_buffers(page),
					from, to, NULL,
					ocfs2_journal_dirty_data);
		if (ret < 0) 
			mlog_errno(ret);
	}
out:
	if (ret) {
		if (handle)
			ocfs2_commit_trans(handle);
		handle = ERR_PTR(ret);
	}
	return handle;
}

static int ocfs2_commit_write(struct file *file, struct page *page,
			      unsigned from, unsigned to)
{
	int ret, extending = 0, locklevel = 0;
	loff_t new_i_size;
	struct buffer_head *di_bh = NULL;
	struct inode *inode = page->mapping->host;
	struct ocfs2_journal_handle *handle = NULL;

	mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);

	/* NOTE: ocfs2_file_aio_write has ensured that it's safe for
	 * us to sample inode->i_size here without the metadata lock:
	 *
	 * 1) We're currently holding the inode alloc lock, so no
	 *    nodes can change it underneath us.
	 *
	 * 2) We've had to take the metadata lock at least once
	 *    already to check for extending writes, hence insuring
	 *    that our current copy is also up to date.
	 */
	new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
	if (new_i_size > i_size_read(inode)) {
		extending = 1;
		locklevel = 1;
	}

	ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, locklevel, page);
	if (ret != 0) {
		mlog_errno(ret);
		goto out;
	}

	ret = ocfs2_data_lock_with_page(inode, 1, page);
	if (ret != 0) {
		mlog_errno(ret);
		goto out_unlock_meta;
	}

	if (extending) {
		handle = ocfs2_start_walk_page_trans(inode, page, from, to);
		if (IS_ERR(handle)) {
			ret = PTR_ERR(handle);
			handle = NULL;
			goto out_unlock_data;
		}

		/* Mark our buffer early. We'd rather catch this error up here
		 * as opposed to after a successful commit_write which would
		 * require us to set back inode->i_size. */
		ret = ocfs2_journal_access(handle, inode, di_bh,
					   OCFS2_JOURNAL_ACCESS_WRITE);
		if (ret < 0) {
			mlog_errno(ret);
			goto out_commit;
		}
	}

	/* might update i_size */
	ret = generic_commit_write(file, page, from, to);
	if (ret < 0) {
		mlog_errno(ret);
		goto out_commit;
	}

	if (extending) {
		loff_t size = (u64) i_size_read(inode);
		struct ocfs2_dinode *di =
			(struct ocfs2_dinode *)di_bh->b_data;

		/* ocfs2_mark_inode_dirty is too heavy to use here. */
		inode->i_blocks = ocfs2_align_bytes_to_sectors(size);
		inode->i_ctime = inode->i_mtime = CURRENT_TIME;

		di->i_size = cpu_to_le64(size);
		di->i_ctime = di->i_mtime = 
				cpu_to_le64(inode->i_mtime.tv_sec);
		di->i_ctime_nsec = di->i_mtime_nsec = 
				cpu_to_le32(inode->i_mtime.tv_nsec);

		ret = ocfs2_journal_dirty(handle, di_bh);
		if (ret < 0) {
			mlog_errno(ret);
			goto out_commit;
		}
	}

	BUG_ON(extending && (i_size_read(inode) != new_i_size));

out_commit:
	if (handle)
		ocfs2_commit_trans(handle);
out_unlock_data:
	ocfs2_data_unlock(inode, 1);
out_unlock_meta:
	ocfs2_meta_unlock(inode, locklevel);
out:
	if (di_bh)
		brelse(di_bh);

	mlog_exit(ret);
	return ret;
}

static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
{
	sector_t status;
	u64 p_blkno = 0;
	int err = 0;
	struct inode *inode = mapping->host;

	mlog_entry("(block = %llu)\n", (unsigned long long)block);

	/* We don't need to lock journal system files, since they aren't
	 * accessed concurrently from multiple nodes.
	 */
	if (!INODE_JOURNAL(inode)) {
		err = ocfs2_meta_lock(inode, NULL, NULL, 0);
		if (err) {
			if (err != -ENOENT)
				mlog_errno(err);
			goto bail;
		}
		down_read(&OCFS2_I(inode)->ip_alloc_sem);
	}

	err = ocfs2_extent_map_get_blocks(inode, block, 1, &p_blkno,
					  NULL);

	if (!INODE_JOURNAL(inode)) {
		up_read(&OCFS2_I(inode)->ip_alloc_sem);
		ocfs2_meta_unlock(inode, 0);
	}

	if (err) {
		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
		     (unsigned long long)block);
		mlog_errno(err);
		goto bail;
	}


bail:
	status = err ? 0 : p_blkno;

	mlog_exit((int)status);

	return status;
}

/*
 * TODO: Make this into a generic get_blocks function.
 *
 * From do_direct_io in direct-io.c:
 *  "So what we do is to permit the ->get_blocks function to populate
 *   bh.b_size with the size of IO which is permitted at this offset and
 *   this i_blkbits."
 *
 * This function is called directly from get_more_blocks in direct-io.c.
 *
 * called like this: dio->get_blocks(dio->inode, fs_startblk,
 * 					fs_count, map_bh, dio->rw == WRITE);
 */
static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
				     struct buffer_head *bh_result, int create)
{
	int ret;
	u64 vbo_max; /* file offset, max_blocks from iblock */
	u64 p_blkno;
	int contig_blocks;
	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
	unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;

	/* This function won't even be called if the request isn't all
	 * nicely aligned and of the right size, so there's no need
	 * for us to check any of that. */

	vbo_max = ((u64)iblock + max_blocks) << blocksize_bits;

	spin_lock(&OCFS2_I(inode)->ip_lock);
	if ((iblock + max_blocks) >
	    ocfs2_clusters_to_blocks(inode->i_sb,
				     OCFS2_I(inode)->ip_clusters)) {
		spin_unlock(&OCFS2_I(inode)->ip_lock);
		ret = -EIO;
		goto bail;
	}
	spin_unlock(&OCFS2_I(inode)->ip_lock);

	/* This figures out the size of the next contiguous block, and
	 * our logical offset */
	ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
					  &contig_blocks);
	if (ret) {
		mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
		     (unsigned long long)iblock);
		ret = -EIO;
		goto bail;
	}

	map_bh(bh_result, inode->i_sb, p_blkno);

	/* make sure we don't map more than max_blocks blocks here as
	   that's all the kernel will handle at this point. */
	if (max_blocks < contig_blocks)
		contig_blocks = max_blocks;
	bh_result->b_size = contig_blocks << blocksize_bits;
bail:
	return ret;
}

/* 
 * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
 * particularly interested in the aio/dio case.  Like the core uses
 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
 * truncation on another.
 */
static void ocfs2_dio_end_io(struct kiocb *iocb,
			     loff_t offset,
			     ssize_t bytes,
			     void *private)
{
	struct inode *inode = iocb->ki_filp->f_dentry->d_inode;

	/* this io's submitter should not have unlocked this before we could */
	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
	ocfs2_iocb_clear_rw_locked(iocb);
	up_read(&inode->i_alloc_sem);
	ocfs2_rw_unlock(inode, 0);
}

static ssize_t ocfs2_direct_IO(int rw,
			       struct kiocb *iocb,
			       const struct iovec *iov,
			       loff_t offset,
			       unsigned long nr_segs)
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_dentry->d_inode->i_mapping->host;
	int ret;

	mlog_entry_void();

	/*
	 * We get PR data locks even for O_DIRECT.  This allows
	 * concurrent O_DIRECT I/O but doesn't let O_DIRECT with
	 * extending and buffered zeroing writes race.  If they did
	 * race then the buffered zeroing could be written back after
	 * the O_DIRECT I/O.  It's one thing to tell people not to mix
	 * buffered and O_DIRECT writes, but expecting them to
	 * understand that file extension is also an implicit buffered
	 * write is too much.  By getting the PR we force writeback of
	 * the buffered zeroing before proceeding.
	 */
	ret = ocfs2_data_lock(inode, 0);
	if (ret < 0) {
		mlog_errno(ret);
		goto out;
	}
	ocfs2_data_unlock(inode, 0);

	ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
					    inode->i_sb->s_bdev, iov, offset,
					    nr_segs, 
					    ocfs2_direct_IO_get_blocks,
					    ocfs2_dio_end_io);
out:
	mlog_exit(ret);
	return ret;
}

const struct address_space_operations ocfs2_aops = {
	.readpage	= ocfs2_readpage,
	.writepage	= ocfs2_writepage,
	.prepare_write	= ocfs2_prepare_write,
	.commit_write	= ocfs2_commit_write,
	.bmap		= ocfs2_bmap,
	.sync_page	= block_sync_page,
	.direct_IO	= ocfs2_direct_IO
};