blob: 93628b02ef5d8899658834e093195e9a702a8693 [file] [log] [blame]
Mark Fashehccd979b2005-12-15 14:31:24 -08001/* -*- 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
28#define MLOG_MASK_PREFIX ML_FILE_IO
29#include <cluster/masklog.h>
30
31#include "ocfs2.h"
32
33#include "alloc.h"
34#include "aops.h"
35#include "dlmglue.h"
36#include "extent_map.h"
37#include "file.h"
38#include "inode.h"
39#include "journal.h"
40#include "super.h"
41#include "symlink.h"
42
43#include "buffer_head_io.h"
44
45static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
46 struct buffer_head *bh_result, int create)
47{
48 int err = -EIO;
49 int status;
50 struct ocfs2_dinode *fe = NULL;
51 struct buffer_head *bh = NULL;
52 struct buffer_head *buffer_cache_bh = NULL;
53 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
54 void *kaddr;
55
56 mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
57 (unsigned long long)iblock, bh_result, create);
58
59 BUG_ON(ocfs2_inode_is_fast_symlink(inode));
60
61 if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
62 mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
63 (unsigned long long)iblock);
64 goto bail;
65 }
66
67 status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
68 OCFS2_I(inode)->ip_blkno,
69 &bh, OCFS2_BH_CACHED, inode);
70 if (status < 0) {
71 mlog_errno(status);
72 goto bail;
73 }
74 fe = (struct ocfs2_dinode *) bh->b_data;
75
76 if (!OCFS2_IS_VALID_DINODE(fe)) {
Mark Fashehb0697052006-03-03 10:24:33 -080077 mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
78 (unsigned long long)fe->i_blkno, 7, fe->i_signature);
Mark Fashehccd979b2005-12-15 14:31:24 -080079 goto bail;
80 }
81
82 if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
83 le32_to_cpu(fe->i_clusters))) {
84 mlog(ML_ERROR, "block offset is outside the allocated size: "
85 "%llu\n", (unsigned long long)iblock);
86 goto bail;
87 }
88
89 /* We don't use the page cache to create symlink data, so if
90 * need be, copy it over from the buffer cache. */
91 if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
92 u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
93 iblock;
94 buffer_cache_bh = sb_getblk(osb->sb, blkno);
95 if (!buffer_cache_bh) {
96 mlog(ML_ERROR, "couldn't getblock for symlink!\n");
97 goto bail;
98 }
99
100 /* we haven't locked out transactions, so a commit
101 * could've happened. Since we've got a reference on
102 * the bh, even if it commits while we're doing the
103 * copy, the data is still good. */
104 if (buffer_jbd(buffer_cache_bh)
105 && ocfs2_inode_is_new(inode)) {
106 kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
107 if (!kaddr) {
108 mlog(ML_ERROR, "couldn't kmap!\n");
109 goto bail;
110 }
111 memcpy(kaddr + (bh_result->b_size * iblock),
112 buffer_cache_bh->b_data,
113 bh_result->b_size);
114 kunmap_atomic(kaddr, KM_USER0);
115 set_buffer_uptodate(bh_result);
116 }
117 brelse(buffer_cache_bh);
118 }
119
120 map_bh(bh_result, inode->i_sb,
121 le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
122
123 err = 0;
124
125bail:
126 if (bh)
127 brelse(bh);
128
129 mlog_exit(err);
130 return err;
131}
132
133static int ocfs2_get_block(struct inode *inode, sector_t iblock,
134 struct buffer_head *bh_result, int create)
135{
136 int err = 0;
137 u64 p_blkno, past_eof;
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 /* this can happen if another node truncs after our extend! */
153 spin_lock(&OCFS2_I(inode)->ip_lock);
154 if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
155 OCFS2_I(inode)->ip_clusters))
156 err = -EIO;
157 spin_unlock(&OCFS2_I(inode)->ip_lock);
158 if (err)
159 goto bail;
160
161 err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
162 NULL);
163 if (err) {
164 mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
Mark Fashehb0697052006-03-03 10:24:33 -0800165 "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
166 (unsigned long long)p_blkno);
Mark Fashehccd979b2005-12-15 14:31:24 -0800167 goto bail;
168 }
169
170 map_bh(bh_result, inode->i_sb, p_blkno);
171
172 if (bh_result->b_blocknr == 0) {
173 err = -EIO;
Mark Fashehb0697052006-03-03 10:24:33 -0800174 mlog(ML_ERROR, "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
175 (unsigned long long)iblock,
176 (unsigned long long)p_blkno,
177 (unsigned long long)OCFS2_I(inode)->ip_blkno);
Mark Fashehccd979b2005-12-15 14:31:24 -0800178 }
179
180 past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
Mark Fashehb0697052006-03-03 10:24:33 -0800181 mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
182 (unsigned long long)past_eof);
Mark Fashehccd979b2005-12-15 14:31:24 -0800183
184 if (create && (iblock >= past_eof))
185 set_buffer_new(bh_result);
186
187bail:
188 if (err < 0)
189 err = -EIO;
190
191 mlog_exit(err);
192 return err;
193}
194
195static int ocfs2_readpage(struct file *file, struct page *page)
196{
197 struct inode *inode = page->mapping->host;
198 loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
199 int ret, unlock = 1;
200
201 mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
202
Mark Fasheh4bcec182006-10-09 16:02:40 -0700203 ret = ocfs2_meta_lock_with_page(inode, NULL, 0, page);
Mark Fashehccd979b2005-12-15 14:31:24 -0800204 if (ret != 0) {
205 if (ret == AOP_TRUNCATED_PAGE)
206 unlock = 0;
207 mlog_errno(ret);
208 goto out;
209 }
210
211 down_read(&OCFS2_I(inode)->ip_alloc_sem);
212
213 /*
214 * i_size might have just been updated as we grabed the meta lock. We
215 * might now be discovering a truncate that hit on another node.
216 * block_read_full_page->get_block freaks out if it is asked to read
217 * beyond the end of a file, so we check here. Callers
218 * (generic_file_read, fault->nopage) are clever enough to check i_size
219 * and notice that the page they just read isn't needed.
220 *
221 * XXX sys_readahead() seems to get that wrong?
222 */
223 if (start >= i_size_read(inode)) {
224 char *addr = kmap(page);
225 memset(addr, 0, PAGE_SIZE);
226 flush_dcache_page(page);
227 kunmap(page);
228 SetPageUptodate(page);
229 ret = 0;
230 goto out_alloc;
231 }
232
233 ret = ocfs2_data_lock_with_page(inode, 0, page);
234 if (ret != 0) {
235 if (ret == AOP_TRUNCATED_PAGE)
236 unlock = 0;
237 mlog_errno(ret);
238 goto out_alloc;
239 }
240
241 ret = block_read_full_page(page, ocfs2_get_block);
242 unlock = 0;
243
244 ocfs2_data_unlock(inode, 0);
245out_alloc:
246 up_read(&OCFS2_I(inode)->ip_alloc_sem);
247 ocfs2_meta_unlock(inode, 0);
248out:
249 if (unlock)
250 unlock_page(page);
251 mlog_exit(ret);
252 return ret;
253}
254
255/* Note: Because we don't support holes, our allocation has
256 * already happened (allocation writes zeros to the file data)
257 * so we don't have to worry about ordered writes in
258 * ocfs2_writepage.
259 *
260 * ->writepage is called during the process of invalidating the page cache
261 * during blocked lock processing. It can't block on any cluster locks
262 * to during block mapping. It's relying on the fact that the block
263 * mapping can't have disappeared under the dirty pages that it is
264 * being asked to write back.
265 */
266static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
267{
268 int ret;
269
270 mlog_entry("(0x%p)\n", page);
271
272 ret = block_write_full_page(page, ocfs2_get_block, wbc);
273
274 mlog_exit(ret);
275
276 return ret;
277}
278
Mark Fasheh53013cb2006-05-05 19:04:03 -0700279/* This can also be called from ocfs2_write_zero_page() which has done
280 * it's own cluster locking. */
281int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
282 unsigned from, unsigned to)
283{
284 int ret;
285
286 down_read(&OCFS2_I(inode)->ip_alloc_sem);
287
288 ret = block_prepare_write(page, from, to, ocfs2_get_block);
289
290 up_read(&OCFS2_I(inode)->ip_alloc_sem);
291
292 return ret;
293}
294
Mark Fashehccd979b2005-12-15 14:31:24 -0800295/*
296 * ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called
297 * from loopback. It must be able to perform its own locking around
298 * ocfs2_get_block().
299 */
Mark Fasheh53013cb2006-05-05 19:04:03 -0700300static int ocfs2_prepare_write(struct file *file, struct page *page,
301 unsigned from, unsigned to)
Mark Fashehccd979b2005-12-15 14:31:24 -0800302{
303 struct inode *inode = page->mapping->host;
304 int ret;
305
306 mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
307
Mark Fasheh4bcec182006-10-09 16:02:40 -0700308 ret = ocfs2_meta_lock_with_page(inode, NULL, 0, page);
Mark Fashehccd979b2005-12-15 14:31:24 -0800309 if (ret != 0) {
310 mlog_errno(ret);
311 goto out;
312 }
313
Mark Fasheh53013cb2006-05-05 19:04:03 -0700314 ret = ocfs2_prepare_write_nolock(inode, page, from, to);
Mark Fashehccd979b2005-12-15 14:31:24 -0800315
316 ocfs2_meta_unlock(inode, 0);
317out:
318 mlog_exit(ret);
319 return ret;
320}
321
322/* Taken from ext3. We don't necessarily need the full blown
323 * functionality yet, but IMHO it's better to cut and paste the whole
324 * thing so we can avoid introducing our own bugs (and easily pick up
325 * their fixes when they happen) --Mark */
326static int walk_page_buffers( handle_t *handle,
327 struct buffer_head *head,
328 unsigned from,
329 unsigned to,
330 int *partial,
331 int (*fn)( handle_t *handle,
332 struct buffer_head *bh))
333{
334 struct buffer_head *bh;
335 unsigned block_start, block_end;
336 unsigned blocksize = head->b_size;
337 int err, ret = 0;
338 struct buffer_head *next;
339
340 for ( bh = head, block_start = 0;
341 ret == 0 && (bh != head || !block_start);
342 block_start = block_end, bh = next)
343 {
344 next = bh->b_this_page;
345 block_end = block_start + blocksize;
346 if (block_end <= from || block_start >= to) {
347 if (partial && !buffer_uptodate(bh))
348 *partial = 1;
349 continue;
350 }
351 err = (*fn)(handle, bh);
352 if (!ret)
353 ret = err;
354 }
355 return ret;
356}
357
Mark Fasheh1fabe142006-10-09 18:11:45 -0700358handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
Mark Fashehccd979b2005-12-15 14:31:24 -0800359 struct page *page,
360 unsigned from,
361 unsigned to)
362{
363 struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
Mark Fasheh1fabe142006-10-09 18:11:45 -0700364 handle_t *handle = NULL;
Mark Fashehccd979b2005-12-15 14:31:24 -0800365 int ret = 0;
366
Mark Fasheh65eff9c2006-10-09 17:26:22 -0700367 handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
Mark Fashehccd979b2005-12-15 14:31:24 -0800368 if (!handle) {
369 ret = -ENOMEM;
370 mlog_errno(ret);
371 goto out;
372 }
373
374 if (ocfs2_should_order_data(inode)) {
Mark Fasheh1fabe142006-10-09 18:11:45 -0700375 ret = walk_page_buffers(handle,
Mark Fashehccd979b2005-12-15 14:31:24 -0800376 page_buffers(page),
377 from, to, NULL,
378 ocfs2_journal_dirty_data);
379 if (ret < 0)
380 mlog_errno(ret);
381 }
382out:
383 if (ret) {
384 if (handle)
Mark Fasheh02dc1af2006-10-09 16:48:10 -0700385 ocfs2_commit_trans(osb, handle);
Mark Fashehccd979b2005-12-15 14:31:24 -0800386 handle = ERR_PTR(ret);
387 }
388 return handle;
389}
390
391static int ocfs2_commit_write(struct file *file, struct page *page,
392 unsigned from, unsigned to)
393{
Mark Fashehe0b40962006-07-11 14:38:54 -0700394 int ret;
Mark Fashehccd979b2005-12-15 14:31:24 -0800395 struct buffer_head *di_bh = NULL;
396 struct inode *inode = page->mapping->host;
Mark Fasheh1fabe142006-10-09 18:11:45 -0700397 handle_t *handle = NULL;
Mark Fashehe0b40962006-07-11 14:38:54 -0700398 struct ocfs2_dinode *di;
Mark Fashehccd979b2005-12-15 14:31:24 -0800399
400 mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
401
402 /* NOTE: ocfs2_file_aio_write has ensured that it's safe for
Mark Fashehe0b40962006-07-11 14:38:54 -0700403 * us to continue here without rechecking the I/O against
404 * changed inode values.
Mark Fashehccd979b2005-12-15 14:31:24 -0800405 *
406 * 1) We're currently holding the inode alloc lock, so no
407 * nodes can change it underneath us.
408 *
409 * 2) We've had to take the metadata lock at least once
Mark Fashehe0b40962006-07-11 14:38:54 -0700410 * already to check for extending writes, suid removal, etc.
411 * The meta data update code then ensures that we don't get a
412 * stale inode allocation image (i_size, i_clusters, etc).
Mark Fashehccd979b2005-12-15 14:31:24 -0800413 */
Mark Fashehccd979b2005-12-15 14:31:24 -0800414
Mark Fasheh4bcec182006-10-09 16:02:40 -0700415 ret = ocfs2_meta_lock_with_page(inode, &di_bh, 1, page);
Mark Fashehccd979b2005-12-15 14:31:24 -0800416 if (ret != 0) {
417 mlog_errno(ret);
418 goto out;
419 }
420
421 ret = ocfs2_data_lock_with_page(inode, 1, page);
422 if (ret != 0) {
423 mlog_errno(ret);
424 goto out_unlock_meta;
425 }
426
Mark Fashehe0b40962006-07-11 14:38:54 -0700427 handle = ocfs2_start_walk_page_trans(inode, page, from, to);
428 if (IS_ERR(handle)) {
429 ret = PTR_ERR(handle);
430 goto out_unlock_data;
431 }
Mark Fashehccd979b2005-12-15 14:31:24 -0800432
Mark Fashehe0b40962006-07-11 14:38:54 -0700433 /* Mark our buffer early. We'd rather catch this error up here
434 * as opposed to after a successful commit_write which would
435 * require us to set back inode->i_size. */
436 ret = ocfs2_journal_access(handle, inode, di_bh,
437 OCFS2_JOURNAL_ACCESS_WRITE);
438 if (ret < 0) {
439 mlog_errno(ret);
440 goto out_commit;
Mark Fashehccd979b2005-12-15 14:31:24 -0800441 }
442
443 /* might update i_size */
444 ret = generic_commit_write(file, page, from, to);
445 if (ret < 0) {
446 mlog_errno(ret);
447 goto out_commit;
448 }
449
Mark Fashehe0b40962006-07-11 14:38:54 -0700450 di = (struct ocfs2_dinode *)di_bh->b_data;
Mark Fashehccd979b2005-12-15 14:31:24 -0800451
Mark Fashehe0b40962006-07-11 14:38:54 -0700452 /* ocfs2_mark_inode_dirty() is too heavy to use here. */
453 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
454 di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
455 di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
Mark Fashehccd979b2005-12-15 14:31:24 -0800456
Mark Fashehe0b40962006-07-11 14:38:54 -0700457 inode->i_blocks = ocfs2_align_bytes_to_sectors((u64)(i_size_read(inode)));
458 di->i_size = cpu_to_le64((u64)i_size_read(inode));
Mark Fashehccd979b2005-12-15 14:31:24 -0800459
Mark Fashehe0b40962006-07-11 14:38:54 -0700460 ret = ocfs2_journal_dirty(handle, di_bh);
461 if (ret < 0) {
462 mlog_errno(ret);
463 goto out_commit;
Mark Fashehccd979b2005-12-15 14:31:24 -0800464 }
465
Mark Fashehccd979b2005-12-15 14:31:24 -0800466out_commit:
Mark Fasheh02dc1af2006-10-09 16:48:10 -0700467 ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
Mark Fashehccd979b2005-12-15 14:31:24 -0800468out_unlock_data:
469 ocfs2_data_unlock(inode, 1);
470out_unlock_meta:
Mark Fashehe0b40962006-07-11 14:38:54 -0700471 ocfs2_meta_unlock(inode, 1);
Mark Fashehccd979b2005-12-15 14:31:24 -0800472out:
473 if (di_bh)
474 brelse(di_bh);
475
476 mlog_exit(ret);
477 return ret;
478}
479
480static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
481{
482 sector_t status;
483 u64 p_blkno = 0;
484 int err = 0;
485 struct inode *inode = mapping->host;
486
487 mlog_entry("(block = %llu)\n", (unsigned long long)block);
488
489 /* We don't need to lock journal system files, since they aren't
490 * accessed concurrently from multiple nodes.
491 */
492 if (!INODE_JOURNAL(inode)) {
Mark Fasheh4bcec182006-10-09 16:02:40 -0700493 err = ocfs2_meta_lock(inode, NULL, 0);
Mark Fashehccd979b2005-12-15 14:31:24 -0800494 if (err) {
495 if (err != -ENOENT)
496 mlog_errno(err);
497 goto bail;
498 }
499 down_read(&OCFS2_I(inode)->ip_alloc_sem);
500 }
501
502 err = ocfs2_extent_map_get_blocks(inode, block, 1, &p_blkno,
503 NULL);
504
505 if (!INODE_JOURNAL(inode)) {
506 up_read(&OCFS2_I(inode)->ip_alloc_sem);
507 ocfs2_meta_unlock(inode, 0);
508 }
509
510 if (err) {
511 mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
512 (unsigned long long)block);
513 mlog_errno(err);
514 goto bail;
515 }
516
517
518bail:
519 status = err ? 0 : p_blkno;
520
521 mlog_exit((int)status);
522
523 return status;
524}
525
526/*
527 * TODO: Make this into a generic get_blocks function.
528 *
529 * From do_direct_io in direct-io.c:
530 * "So what we do is to permit the ->get_blocks function to populate
531 * bh.b_size with the size of IO which is permitted at this offset and
532 * this i_blkbits."
533 *
534 * This function is called directly from get_more_blocks in direct-io.c.
535 *
536 * called like this: dio->get_blocks(dio->inode, fs_startblk,
537 * fs_count, map_bh, dio->rw == WRITE);
538 */
539static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
Mark Fashehccd979b2005-12-15 14:31:24 -0800540 struct buffer_head *bh_result, int create)
541{
542 int ret;
Mark Fasheh564f8a32006-12-14 13:01:05 -0800543 u64 p_blkno, inode_blocks;
Mark Fashehccd979b2005-12-15 14:31:24 -0800544 int contig_blocks;
Florin Malita184d7d22006-06-03 19:30:10 -0400545 unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800546 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
Mark Fashehccd979b2005-12-15 14:31:24 -0800547
Mark Fashehccd979b2005-12-15 14:31:24 -0800548 /* This function won't even be called if the request isn't all
549 * nicely aligned and of the right size, so there's no need
550 * for us to check any of that. */
551
Mark Fashehccd979b2005-12-15 14:31:24 -0800552 spin_lock(&OCFS2_I(inode)->ip_lock);
Mark Fasheh564f8a32006-12-14 13:01:05 -0800553 inode_blocks = ocfs2_clusters_to_blocks(inode->i_sb,
554 OCFS2_I(inode)->ip_clusters);
555
556 /*
557 * For a read which begins past the end of file, we return a hole.
558 */
559 if (!create && (iblock >= inode_blocks)) {
560 spin_unlock(&OCFS2_I(inode)->ip_lock);
561 ret = 0;
562 goto bail;
563 }
564
565 /*
566 * Any write past EOF is not allowed because we'd be extending.
567 */
568 if (create && (iblock + max_blocks) > inode_blocks) {
Mark Fashehccd979b2005-12-15 14:31:24 -0800569 spin_unlock(&OCFS2_I(inode)->ip_lock);
570 ret = -EIO;
571 goto bail;
572 }
573 spin_unlock(&OCFS2_I(inode)->ip_lock);
574
575 /* This figures out the size of the next contiguous block, and
576 * our logical offset */
577 ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
578 &contig_blocks);
579 if (ret) {
580 mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
581 (unsigned long long)iblock);
582 ret = -EIO;
583 goto bail;
584 }
585
586 map_bh(bh_result, inode->i_sb, p_blkno);
587
588 /* make sure we don't map more than max_blocks blocks here as
589 that's all the kernel will handle at this point. */
590 if (max_blocks < contig_blocks)
591 contig_blocks = max_blocks;
592 bh_result->b_size = contig_blocks << blocksize_bits;
593bail:
594 return ret;
595}
596
597/*
598 * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're
599 * particularly interested in the aio/dio case. Like the core uses
600 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
601 * truncation on another.
602 */
603static void ocfs2_dio_end_io(struct kiocb *iocb,
604 loff_t offset,
605 ssize_t bytes,
606 void *private)
607{
Josef Sipekd28c9172006-12-08 02:37:25 -0800608 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
Mark Fashehccd979b2005-12-15 14:31:24 -0800609
610 /* this io's submitter should not have unlocked this before we could */
611 BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
612 ocfs2_iocb_clear_rw_locked(iocb);
613 up_read(&inode->i_alloc_sem);
614 ocfs2_rw_unlock(inode, 0);
615}
616
617static ssize_t ocfs2_direct_IO(int rw,
618 struct kiocb *iocb,
619 const struct iovec *iov,
620 loff_t offset,
621 unsigned long nr_segs)
622{
623 struct file *file = iocb->ki_filp;
Josef Sipekd28c9172006-12-08 02:37:25 -0800624 struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
Mark Fashehccd979b2005-12-15 14:31:24 -0800625 int ret;
626
627 mlog_entry_void();
Mark Fasheh53013cb2006-05-05 19:04:03 -0700628
629 /*
630 * We get PR data locks even for O_DIRECT. This allows
631 * concurrent O_DIRECT I/O but doesn't let O_DIRECT with
632 * extending and buffered zeroing writes race. If they did
633 * race then the buffered zeroing could be written back after
634 * the O_DIRECT I/O. It's one thing to tell people not to mix
635 * buffered and O_DIRECT writes, but expecting them to
636 * understand that file extension is also an implicit buffered
637 * write is too much. By getting the PR we force writeback of
638 * the buffered zeroing before proceeding.
639 */
640 ret = ocfs2_data_lock(inode, 0);
641 if (ret < 0) {
642 mlog_errno(ret);
643 goto out;
644 }
645 ocfs2_data_unlock(inode, 0);
646
Mark Fashehccd979b2005-12-15 14:31:24 -0800647 ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
648 inode->i_sb->s_bdev, iov, offset,
649 nr_segs,
650 ocfs2_direct_IO_get_blocks,
651 ocfs2_dio_end_io);
Mark Fasheh53013cb2006-05-05 19:04:03 -0700652out:
Mark Fashehccd979b2005-12-15 14:31:24 -0800653 mlog_exit(ret);
654 return ret;
655}
656
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700657const struct address_space_operations ocfs2_aops = {
Mark Fashehccd979b2005-12-15 14:31:24 -0800658 .readpage = ocfs2_readpage,
659 .writepage = ocfs2_writepage,
660 .prepare_write = ocfs2_prepare_write,
661 .commit_write = ocfs2_commit_write,
662 .bmap = ocfs2_bmap,
663 .sync_page = block_sync_page,
664 .direct_IO = ocfs2_direct_IO
665};