blob: ca4ab7ce85bf6d53a5669e3fbf0cdcfc2c43a6a2 [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 * io.c
5 *
6 * Buffer cache handling
7 *
8 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
25
26#include <linux/fs.h>
27#include <linux/types.h>
28#include <linux/slab.h>
29#include <linux/highmem.h>
30
31#include <cluster/masklog.h>
32
33#include "ocfs2.h"
34
35#include "alloc.h"
36#include "inode.h"
37#include "journal.h"
38#include "uptodate.h"
39
40#include "buffer_head_io.h"
41
42int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
43 struct inode *inode)
44{
45 int ret = 0;
46
47 mlog_entry("(bh->b_blocknr = %llu, inode=%p)\n",
48 (unsigned long long)bh->b_blocknr, inode);
49
50 BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO);
51 BUG_ON(buffer_jbd(bh));
52
53 /* No need to check for a soft readonly file system here. non
54 * journalled writes are only ever done on system files which
55 * can get modified during recovery even if read-only. */
56 if (ocfs2_is_hard_readonly(osb)) {
57 ret = -EROFS;
58 goto out;
59 }
60
Mark Fasheh251b6ec2006-01-10 15:41:43 -080061 mutex_lock(&OCFS2_I(inode)->ip_io_mutex);
Mark Fashehccd979b2005-12-15 14:31:24 -080062
63 lock_buffer(bh);
64 set_buffer_uptodate(bh);
65
66 /* remove from dirty list before I/O. */
67 clear_buffer_dirty(bh);
68
Joel Beckerda1e9092008-10-09 17:20:29 -070069 get_bh(bh); /* for end_buffer_write_sync() */
Mark Fashehccd979b2005-12-15 14:31:24 -080070 bh->b_end_io = end_buffer_write_sync;
71 submit_bh(WRITE, bh);
72
73 wait_on_buffer(bh);
74
75 if (buffer_uptodate(bh)) {
76 ocfs2_set_buffer_uptodate(inode, bh);
77 } else {
78 /* We don't need to remove the clustered uptodate
79 * information for this bh as it's not marked locally
80 * uptodate. */
81 ret = -EIO;
Mark Fasheh2fe5c1d2008-01-23 18:35:31 -080082 put_bh(bh);
Mark Fashehccd979b2005-12-15 14:31:24 -080083 }
84
Mark Fasheh251b6ec2006-01-10 15:41:43 -080085 mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);
Mark Fashehccd979b2005-12-15 14:31:24 -080086out:
87 mlog_exit(ret);
88 return ret;
89}
90
Joel Beckerda1e9092008-10-09 17:20:29 -070091int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
92 unsigned int nr, struct buffer_head *bhs[])
93{
94 int status = 0;
95 unsigned int i;
96 struct buffer_head *bh;
97
98 if (!nr) {
99 mlog(ML_BH_IO, "No buffers will be read!\n");
100 goto bail;
101 }
102
103 for (i = 0 ; i < nr ; i++) {
104 if (bhs[i] == NULL) {
105 bhs[i] = sb_getblk(osb->sb, block++);
106 if (bhs[i] == NULL) {
107 status = -EIO;
108 mlog_errno(status);
109 goto bail;
110 }
111 }
112 bh = bhs[i];
113
114 if (buffer_jbd(bh)) {
115 mlog(ML_ERROR,
116 "trying to sync read a jbd "
117 "managed bh (blocknr = %llu), skipping\n",
118 (unsigned long long)bh->b_blocknr);
119 continue;
120 }
121
122 if (buffer_dirty(bh)) {
123 /* This should probably be a BUG, or
124 * at least return an error. */
125 mlog(ML_ERROR,
126 "trying to sync read a dirty "
127 "buffer! (blocknr = %llu), skipping\n",
128 (unsigned long long)bh->b_blocknr);
129 continue;
130 }
131
132 lock_buffer(bh);
133 if (buffer_jbd(bh)) {
134 mlog(ML_ERROR,
135 "block %llu had the JBD bit set "
136 "while I was in lock_buffer!",
137 (unsigned long long)bh->b_blocknr);
138 BUG();
139 }
140
141 clear_buffer_uptodate(bh);
142 get_bh(bh); /* for end_buffer_read_sync() */
143 bh->b_end_io = end_buffer_read_sync;
144 submit_bh(READ, bh);
145 }
146
147 for (i = nr; i > 0; i--) {
148 bh = bhs[i - 1];
149
150 if (buffer_jbd(bh)) {
151 mlog(ML_ERROR,
152 "the journal got the buffer while it was "
153 "locked for io! (blocknr = %llu)\n",
154 (unsigned long long)bh->b_blocknr);
155 BUG();
156 }
157
158 wait_on_buffer(bh);
159 if (!buffer_uptodate(bh)) {
160 /* Status won't be cleared from here on out,
161 * so we can safely record this and loop back
162 * to cleanup the other buffers. */
163 status = -EIO;
164 put_bh(bh);
165 bhs[i - 1] = NULL;
166 }
167 }
168
169bail:
170 return status;
171}
172
Mark Fashehccd979b2005-12-15 14:31:24 -0800173int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
174 struct buffer_head *bhs[], int flags,
175 struct inode *inode)
176{
177 int status = 0;
178 struct super_block *sb;
179 int i, ignore_cache = 0;
180 struct buffer_head *bh;
181
Mark Fashehb06970532006-03-03 10:24:33 -0800182 mlog_entry("(block=(%llu), nr=(%d), flags=%d, inode=%p)\n",
183 (unsigned long long)block, nr, flags, inode);
Mark Fashehccd979b2005-12-15 14:31:24 -0800184
Mark Fashehaa958872006-04-21 13:49:02 -0700185 BUG_ON((flags & OCFS2_BH_READAHEAD) &&
186 (!inode || !(flags & OCFS2_BH_CACHED)));
187
Mark Fashehccd979b2005-12-15 14:31:24 -0800188 if (osb == NULL || osb->sb == NULL || bhs == NULL) {
189 status = -EINVAL;
190 mlog_errno(status);
191 goto bail;
192 }
193
194 if (nr < 0) {
195 mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
196 status = -EINVAL;
197 mlog_errno(status);
198 goto bail;
199 }
200
201 if (nr == 0) {
202 mlog(ML_BH_IO, "No buffers will be read!\n");
203 status = 0;
204 goto bail;
205 }
206
207 sb = osb->sb;
208
209 if (flags & OCFS2_BH_CACHED && !inode)
210 flags &= ~OCFS2_BH_CACHED;
211
212 if (inode)
Mark Fasheh251b6ec2006-01-10 15:41:43 -0800213 mutex_lock(&OCFS2_I(inode)->ip_io_mutex);
Mark Fashehccd979b2005-12-15 14:31:24 -0800214 for (i = 0 ; i < nr ; i++) {
215 if (bhs[i] == NULL) {
216 bhs[i] = sb_getblk(sb, block++);
217 if (bhs[i] == NULL) {
218 if (inode)
Mark Fasheh251b6ec2006-01-10 15:41:43 -0800219 mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);
Mark Fashehccd979b2005-12-15 14:31:24 -0800220 status = -EIO;
221 mlog_errno(status);
222 goto bail;
223 }
224 }
225 bh = bhs[i];
226 ignore_cache = 0;
227
Mark Fashehaa958872006-04-21 13:49:02 -0700228 /* There are three read-ahead cases here which we need to
229 * be concerned with. All three assume a buffer has
230 * previously been submitted with OCFS2_BH_READAHEAD
231 * and it hasn't yet completed I/O.
232 *
233 * 1) The current request is sync to disk. This rarely
234 * happens these days, and never when performance
235 * matters - the code can just wait on the buffer
236 * lock and re-submit.
237 *
238 * 2) The current request is cached, but not
239 * readahead. ocfs2_buffer_uptodate() will return
240 * false anyway, so we'll wind up waiting on the
241 * buffer lock to do I/O. We re-check the request
242 * with after getting the lock to avoid a re-submit.
243 *
244 * 3) The current request is readahead (and so must
245 * also be a caching one). We short circuit if the
246 * buffer is locked (under I/O) and if it's in the
247 * uptodate cache. The re-check from #2 catches the
248 * case that the previous read-ahead completes just
249 * before our is-it-in-flight check.
250 */
251
Mark Fashehccd979b2005-12-15 14:31:24 -0800252 if (flags & OCFS2_BH_CACHED &&
253 !ocfs2_buffer_uptodate(inode, bh)) {
254 mlog(ML_UPTODATE,
Mark Fashehb06970532006-03-03 10:24:33 -0800255 "bh (%llu), inode %llu not uptodate\n",
Mark Fashehccd979b2005-12-15 14:31:24 -0800256 (unsigned long long)bh->b_blocknr,
Mark Fashehb06970532006-03-03 10:24:33 -0800257 (unsigned long long)OCFS2_I(inode)->ip_blkno);
Mark Fashehccd979b2005-12-15 14:31:24 -0800258 ignore_cache = 1;
259 }
260
261 /* XXX: Can we ever get this and *not* have the cached
262 * flag set? */
263 if (buffer_jbd(bh)) {
264 if (!(flags & OCFS2_BH_CACHED) || ignore_cache)
265 mlog(ML_BH_IO, "trying to sync read a jbd "
266 "managed bh (blocknr = %llu)\n",
267 (unsigned long long)bh->b_blocknr);
268 continue;
269 }
270
271 if (!(flags & OCFS2_BH_CACHED) || ignore_cache) {
272 if (buffer_dirty(bh)) {
273 /* This should probably be a BUG, or
274 * at least return an error. */
275 mlog(ML_BH_IO, "asking me to sync read a dirty "
276 "buffer! (blocknr = %llu)\n",
277 (unsigned long long)bh->b_blocknr);
278 continue;
279 }
280
Mark Fashehaa958872006-04-21 13:49:02 -0700281 /* A read-ahead request was made - if the
282 * buffer is already under read-ahead from a
283 * previously submitted request than we are
284 * done here. */
285 if ((flags & OCFS2_BH_READAHEAD)
286 && ocfs2_buffer_read_ahead(inode, bh))
287 continue;
288
Mark Fashehccd979b2005-12-15 14:31:24 -0800289 lock_buffer(bh);
290 if (buffer_jbd(bh)) {
291#ifdef CATCH_BH_JBD_RACES
292 mlog(ML_ERROR, "block %llu had the JBD bit set "
293 "while I was in lock_buffer!",
294 (unsigned long long)bh->b_blocknr);
295 BUG();
296#else
297 unlock_buffer(bh);
298 continue;
299#endif
300 }
Mark Fashehaa958872006-04-21 13:49:02 -0700301
302 /* Re-check ocfs2_buffer_uptodate() as a
303 * previously read-ahead buffer may have
304 * completed I/O while we were waiting for the
305 * buffer lock. */
306 if ((flags & OCFS2_BH_CACHED)
307 && !(flags & OCFS2_BH_READAHEAD)
308 && ocfs2_buffer_uptodate(inode, bh)) {
309 unlock_buffer(bh);
310 continue;
311 }
312
Mark Fashehccd979b2005-12-15 14:31:24 -0800313 clear_buffer_uptodate(bh);
314 get_bh(bh); /* for end_buffer_read_sync() */
315 bh->b_end_io = end_buffer_read_sync;
Mark Fashehaa958872006-04-21 13:49:02 -0700316 submit_bh(READ, bh);
Mark Fashehccd979b2005-12-15 14:31:24 -0800317 continue;
318 }
319 }
320
321 status = 0;
322
323 for (i = (nr - 1); i >= 0; i--) {
324 bh = bhs[i];
325
Mark Fashehaa958872006-04-21 13:49:02 -0700326 if (!(flags & OCFS2_BH_READAHEAD)) {
327 /* We know this can't have changed as we hold the
328 * inode sem. Avoid doing any work on the bh if the
329 * journal has it. */
330 if (!buffer_jbd(bh))
331 wait_on_buffer(bh);
Mark Fashehccd979b2005-12-15 14:31:24 -0800332
Mark Fashehaa958872006-04-21 13:49:02 -0700333 if (!buffer_uptodate(bh)) {
334 /* Status won't be cleared from here on out,
335 * so we can safely record this and loop back
336 * to cleanup the other buffers. Don't need to
337 * remove the clustered uptodate information
338 * for this bh as it's not marked locally
339 * uptodate. */
340 status = -EIO;
Mark Fasheh2fe5c1d2008-01-23 18:35:31 -0800341 put_bh(bh);
Mark Fashehaa958872006-04-21 13:49:02 -0700342 bhs[i] = NULL;
343 continue;
344 }
Mark Fashehccd979b2005-12-15 14:31:24 -0800345 }
346
Mark Fashehaa958872006-04-21 13:49:02 -0700347 /* Always set the buffer in the cache, even if it was
348 * a forced read, or read-ahead which hasn't yet
349 * completed. */
Mark Fashehccd979b2005-12-15 14:31:24 -0800350 if (inode)
351 ocfs2_set_buffer_uptodate(inode, bh);
352 }
353 if (inode)
Mark Fasheh251b6ec2006-01-10 15:41:43 -0800354 mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);
Mark Fashehccd979b2005-12-15 14:31:24 -0800355
Mark Fashehaa958872006-04-21 13:49:02 -0700356 mlog(ML_BH_IO, "block=(%llu), nr=(%d), cached=%s, flags=0x%x\n",
Mark Fashehb06970532006-03-03 10:24:33 -0800357 (unsigned long long)block, nr,
Mark Fashehaa958872006-04-21 13:49:02 -0700358 (!(flags & OCFS2_BH_CACHED) || ignore_cache) ? "no" : "yes", flags);
Mark Fashehccd979b2005-12-15 14:31:24 -0800359
360bail:
361
362 mlog_exit(status);
363 return status;
364}
Tao Mad6590722007-12-18 15:47:03 +0800365
366/* Check whether the blkno is the super block or one of the backups. */
367static void ocfs2_check_super_or_backup(struct super_block *sb,
368 sector_t blkno)
369{
370 int i;
371 u64 backup_blkno;
372
373 if (blkno == OCFS2_SUPER_BLOCK_BLKNO)
374 return;
375
376 for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
377 backup_blkno = ocfs2_backup_super_blkno(sb, i);
378 if (backup_blkno == blkno)
379 return;
380 }
381
382 BUG();
383}
384
385/*
386 * Write super block and backups doesn't need to collaborate with journal,
387 * so we don't need to lock ip_io_mutex and inode doesn't need to bea passed
388 * into this function.
389 */
390int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
391 struct buffer_head *bh)
392{
393 int ret = 0;
394
395 mlog_entry_void();
396
397 BUG_ON(buffer_jbd(bh));
398 ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr);
399
400 if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) {
401 ret = -EROFS;
402 goto out;
403 }
404
405 lock_buffer(bh);
406 set_buffer_uptodate(bh);
407
408 /* remove from dirty list before I/O. */
409 clear_buffer_dirty(bh);
410
411 get_bh(bh); /* for end_buffer_write_sync() */
412 bh->b_end_io = end_buffer_write_sync;
413 submit_bh(WRITE, bh);
414
415 wait_on_buffer(bh);
416
417 if (!buffer_uptodate(bh)) {
418 ret = -EIO;
Mark Fasheh2fe5c1d2008-01-23 18:35:31 -0800419 put_bh(bh);
Tao Mad6590722007-12-18 15:47:03 +0800420 }
421
422out:
423 mlog_exit(ret);
424 return ret;
425}