blob: f9d5d3ffc75a9011b0a63a76a97184853ee7f063 [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>
Mark Fashehccd979b2005-12-15 14:31:24 -080028#include <linux/highmem.h>
29
30#include <cluster/masklog.h>
31
32#include "ocfs2.h"
33
34#include "alloc.h"
35#include "inode.h"
36#include "journal.h"
37#include "uptodate.h"
38
39#include "buffer_head_io.h"
40
Joel Becker970e4932008-11-13 14:49:19 -080041/*
42 * Bits on bh->b_state used by ocfs2.
43 *
Mark Fashehb86c86f2008-11-18 17:16:47 -080044 * These MUST be after the JBD2 bits. Hence, we use BH_JBDPrivateStart.
Joel Becker970e4932008-11-13 14:49:19 -080045 */
46enum ocfs2_state_bits {
Mark Fashehb86c86f2008-11-18 17:16:47 -080047 BH_NeedsValidate = BH_JBDPrivateStart,
Joel Becker970e4932008-11-13 14:49:19 -080048};
49
50/* Expand the magic b_state functions */
51BUFFER_FNS(NeedsValidate, needs_validate);
52
Mark Fashehccd979b2005-12-15 14:31:24 -080053int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
Joel Becker8cb471e2009-02-10 20:00:41 -080054 struct ocfs2_caching_info *ci)
Mark Fashehccd979b2005-12-15 14:31:24 -080055{
56 int ret = 0;
57
Joel Becker8cb471e2009-02-10 20:00:41 -080058 mlog_entry("(bh->b_blocknr = %llu, ci=%p)\n",
59 (unsigned long long)bh->b_blocknr, ci);
Mark Fashehccd979b2005-12-15 14:31:24 -080060
61 BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO);
62 BUG_ON(buffer_jbd(bh));
63
64 /* No need to check for a soft readonly file system here. non
65 * journalled writes are only ever done on system files which
66 * can get modified during recovery even if read-only. */
67 if (ocfs2_is_hard_readonly(osb)) {
68 ret = -EROFS;
69 goto out;
70 }
71
Joel Becker8cb471e2009-02-10 20:00:41 -080072 ocfs2_metadata_cache_io_lock(ci);
Mark Fashehccd979b2005-12-15 14:31:24 -080073
74 lock_buffer(bh);
75 set_buffer_uptodate(bh);
76
77 /* remove from dirty list before I/O. */
78 clear_buffer_dirty(bh);
79
Joel Beckerda1e9092008-10-09 17:20:29 -070080 get_bh(bh); /* for end_buffer_write_sync() */
Mark Fashehccd979b2005-12-15 14:31:24 -080081 bh->b_end_io = end_buffer_write_sync;
82 submit_bh(WRITE, bh);
83
84 wait_on_buffer(bh);
85
86 if (buffer_uptodate(bh)) {
Joel Becker8cb471e2009-02-10 20:00:41 -080087 ocfs2_set_buffer_uptodate(ci, bh);
Mark Fashehccd979b2005-12-15 14:31:24 -080088 } else {
89 /* We don't need to remove the clustered uptodate
90 * information for this bh as it's not marked locally
91 * uptodate. */
92 ret = -EIO;
Mark Fasheh2fe5c1d2008-01-23 18:35:31 -080093 put_bh(bh);
Mark Fashehccd979b2005-12-15 14:31:24 -080094 }
95
Joel Becker8cb471e2009-02-10 20:00:41 -080096 ocfs2_metadata_cache_io_unlock(ci);
Mark Fashehccd979b2005-12-15 14:31:24 -080097out:
98 mlog_exit(ret);
99 return ret;
100}
101
Joel Beckerda1e9092008-10-09 17:20:29 -0700102int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
103 unsigned int nr, struct buffer_head *bhs[])
104{
105 int status = 0;
106 unsigned int i;
107 struct buffer_head *bh;
108
109 if (!nr) {
110 mlog(ML_BH_IO, "No buffers will be read!\n");
111 goto bail;
112 }
113
114 for (i = 0 ; i < nr ; i++) {
115 if (bhs[i] == NULL) {
116 bhs[i] = sb_getblk(osb->sb, block++);
117 if (bhs[i] == NULL) {
118 status = -EIO;
119 mlog_errno(status);
120 goto bail;
121 }
122 }
123 bh = bhs[i];
124
125 if (buffer_jbd(bh)) {
Mark Fashehd6b58f82008-11-21 14:06:55 -0800126 mlog(ML_BH_IO,
Joel Beckerda1e9092008-10-09 17:20:29 -0700127 "trying to sync read a jbd "
128 "managed bh (blocknr = %llu), skipping\n",
129 (unsigned long long)bh->b_blocknr);
130 continue;
131 }
132
133 if (buffer_dirty(bh)) {
134 /* This should probably be a BUG, or
135 * at least return an error. */
136 mlog(ML_ERROR,
137 "trying to sync read a dirty "
138 "buffer! (blocknr = %llu), skipping\n",
139 (unsigned long long)bh->b_blocknr);
140 continue;
141 }
142
143 lock_buffer(bh);
144 if (buffer_jbd(bh)) {
145 mlog(ML_ERROR,
146 "block %llu had the JBD bit set "
147 "while I was in lock_buffer!",
148 (unsigned long long)bh->b_blocknr);
149 BUG();
150 }
151
152 clear_buffer_uptodate(bh);
153 get_bh(bh); /* for end_buffer_read_sync() */
154 bh->b_end_io = end_buffer_read_sync;
155 submit_bh(READ, bh);
156 }
157
158 for (i = nr; i > 0; i--) {
159 bh = bhs[i - 1];
160
Mark Fashehd6b58f82008-11-21 14:06:55 -0800161 /* No need to wait on the buffer if it's managed by JBD. */
162 if (!buffer_jbd(bh))
163 wait_on_buffer(bh);
Joel Beckerda1e9092008-10-09 17:20:29 -0700164
Joel Beckerda1e9092008-10-09 17:20:29 -0700165 if (!buffer_uptodate(bh)) {
166 /* Status won't be cleared from here on out,
167 * so we can safely record this and loop back
168 * to cleanup the other buffers. */
169 status = -EIO;
170 put_bh(bh);
171 bhs[i - 1] = NULL;
172 }
173 }
174
175bail:
176 return status;
177}
178
Joel Becker8cb471e2009-02-10 20:00:41 -0800179int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
Joel Becker970e4932008-11-13 14:49:19 -0800180 struct buffer_head *bhs[], int flags,
181 int (*validate)(struct super_block *sb,
182 struct buffer_head *bh))
Mark Fashehccd979b2005-12-15 14:31:24 -0800183{
184 int status = 0;
Mark Fashehccd979b2005-12-15 14:31:24 -0800185 int i, ignore_cache = 0;
186 struct buffer_head *bh;
Joel Becker8cb471e2009-02-10 20:00:41 -0800187 struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
Mark Fashehccd979b2005-12-15 14:31:24 -0800188
Joel Becker8cb471e2009-02-10 20:00:41 -0800189 mlog_entry("(ci=%p, block=(%llu), nr=(%d), flags=%d)\n",
190 ci, (unsigned long long)block, nr, flags);
Mark Fashehccd979b2005-12-15 14:31:24 -0800191
Joel Becker8cb471e2009-02-10 20:00:41 -0800192 BUG_ON(!ci);
Joel Beckerd4a8c932008-10-09 17:20:34 -0700193 BUG_ON((flags & OCFS2_BH_READAHEAD) &&
194 (flags & OCFS2_BH_IGNORE_CACHE));
Mark Fashehaa958872006-04-21 13:49:02 -0700195
Joel Becker31d33072008-10-09 17:20:30 -0700196 if (bhs == NULL) {
Mark Fashehccd979b2005-12-15 14:31:24 -0800197 status = -EINVAL;
198 mlog_errno(status);
199 goto bail;
200 }
201
202 if (nr < 0) {
203 mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
204 status = -EINVAL;
205 mlog_errno(status);
206 goto bail;
207 }
208
209 if (nr == 0) {
210 mlog(ML_BH_IO, "No buffers will be read!\n");
211 status = 0;
212 goto bail;
213 }
214
Joel Becker8cb471e2009-02-10 20:00:41 -0800215 ocfs2_metadata_cache_io_lock(ci);
Mark Fashehccd979b2005-12-15 14:31:24 -0800216 for (i = 0 ; i < nr ; i++) {
217 if (bhs[i] == NULL) {
Joel Becker8cb471e2009-02-10 20:00:41 -0800218 bhs[i] = sb_getblk(sb, block++);
Mark Fashehccd979b2005-12-15 14:31:24 -0800219 if (bhs[i] == NULL) {
Joel Becker8cb471e2009-02-10 20:00:41 -0800220 ocfs2_metadata_cache_io_unlock(ci);
Mark Fashehccd979b2005-12-15 14:31:24 -0800221 status = -EIO;
222 mlog_errno(status);
223 goto bail;
224 }
225 }
226 bh = bhs[i];
Joel Beckerd4a8c932008-10-09 17:20:34 -0700227 ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE);
Mark Fashehccd979b2005-12-15 14:31:24 -0800228
Mark Fashehaa958872006-04-21 13:49:02 -0700229 /* There are three read-ahead cases here which we need to
230 * be concerned with. All three assume a buffer has
231 * previously been submitted with OCFS2_BH_READAHEAD
232 * and it hasn't yet completed I/O.
233 *
234 * 1) The current request is sync to disk. This rarely
235 * happens these days, and never when performance
236 * matters - the code can just wait on the buffer
237 * lock and re-submit.
238 *
239 * 2) The current request is cached, but not
240 * readahead. ocfs2_buffer_uptodate() will return
241 * false anyway, so we'll wind up waiting on the
242 * buffer lock to do I/O. We re-check the request
243 * with after getting the lock to avoid a re-submit.
244 *
245 * 3) The current request is readahead (and so must
246 * also be a caching one). We short circuit if the
247 * buffer is locked (under I/O) and if it's in the
248 * uptodate cache. The re-check from #2 catches the
249 * case that the previous read-ahead completes just
250 * before our is-it-in-flight check.
251 */
252
Joel Becker8cb471e2009-02-10 20:00:41 -0800253 if (!ignore_cache && !ocfs2_buffer_uptodate(ci, bh)) {
Mark Fashehccd979b2005-12-15 14:31:24 -0800254 mlog(ML_UPTODATE,
Joel Becker8cb471e2009-02-10 20:00:41 -0800255 "bh (%llu), owner %llu not uptodate\n",
Mark Fashehccd979b2005-12-15 14:31:24 -0800256 (unsigned long long)bh->b_blocknr,
Joel Becker8cb471e2009-02-10 20:00:41 -0800257 (unsigned long long)ocfs2_metadata_cache_owner(ci));
Joel Beckerd4a8c932008-10-09 17:20:34 -0700258 /* We're using ignore_cache here to say
259 * "go to disk" */
Mark Fashehccd979b2005-12-15 14:31:24 -0800260 ignore_cache = 1;
261 }
262
Mark Fashehccd979b2005-12-15 14:31:24 -0800263 if (buffer_jbd(bh)) {
Joel Beckerd4a8c932008-10-09 17:20:34 -0700264 if (ignore_cache)
Mark Fashehccd979b2005-12-15 14:31:24 -0800265 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
Joel Beckerd4a8c932008-10-09 17:20:34 -0700271 if (ignore_cache) {
Mark Fashehccd979b2005-12-15 14:31:24 -0800272 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)
Joel Becker8cb471e2009-02-10 20:00:41 -0800286 && ocfs2_buffer_read_ahead(ci, bh))
Mark Fashehaa958872006-04-21 13:49:02 -0700287 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. */
Joel Beckerd4a8c932008-10-09 17:20:34 -0700306 if (!(flags & OCFS2_BH_IGNORE_CACHE)
Mark Fashehaa958872006-04-21 13:49:02 -0700307 && !(flags & OCFS2_BH_READAHEAD)
Joel Becker8cb471e2009-02-10 20:00:41 -0800308 && ocfs2_buffer_uptodate(ci, bh)) {
Mark Fashehaa958872006-04-21 13:49:02 -0700309 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() */
Joel Becker970e4932008-11-13 14:49:19 -0800315 if (validate)
316 set_buffer_needs_validate(bh);
Mark Fashehccd979b2005-12-15 14:31:24 -0800317 bh->b_end_io = end_buffer_read_sync;
Mark Fashehaa958872006-04-21 13:49:02 -0700318 submit_bh(READ, bh);
Mark Fashehccd979b2005-12-15 14:31:24 -0800319 continue;
320 }
321 }
322
323 status = 0;
324
325 for (i = (nr - 1); i >= 0; i--) {
326 bh = bhs[i];
327
Mark Fashehaa958872006-04-21 13:49:02 -0700328 if (!(flags & OCFS2_BH_READAHEAD)) {
329 /* We know this can't have changed as we hold the
Joel Becker8cb471e2009-02-10 20:00:41 -0800330 * owner sem. Avoid doing any work on the bh if the
Mark Fashehaa958872006-04-21 13:49:02 -0700331 * journal has it. */
332 if (!buffer_jbd(bh))
333 wait_on_buffer(bh);
Mark Fashehccd979b2005-12-15 14:31:24 -0800334
Mark Fashehaa958872006-04-21 13:49:02 -0700335 if (!buffer_uptodate(bh)) {
336 /* Status won't be cleared from here on out,
337 * so we can safely record this and loop back
338 * to cleanup the other buffers. Don't need to
339 * remove the clustered uptodate information
340 * for this bh as it's not marked locally
341 * uptodate. */
342 status = -EIO;
Mark Fasheh2fe5c1d2008-01-23 18:35:31 -0800343 put_bh(bh);
Mark Fashehaa958872006-04-21 13:49:02 -0700344 bhs[i] = NULL;
345 continue;
346 }
Joel Becker970e4932008-11-13 14:49:19 -0800347
348 if (buffer_needs_validate(bh)) {
349 /* We never set NeedsValidate if the
350 * buffer was held by the journal, so
351 * that better not have changed */
352 BUG_ON(buffer_jbd(bh));
353 clear_buffer_needs_validate(bh);
Joel Becker8cb471e2009-02-10 20:00:41 -0800354 status = validate(sb, bh);
Joel Becker970e4932008-11-13 14:49:19 -0800355 if (status) {
356 put_bh(bh);
357 bhs[i] = NULL;
358 continue;
359 }
360 }
Mark Fashehccd979b2005-12-15 14:31:24 -0800361 }
362
Mark Fashehaa958872006-04-21 13:49:02 -0700363 /* Always set the buffer in the cache, even if it was
364 * a forced read, or read-ahead which hasn't yet
365 * completed. */
Joel Becker8cb471e2009-02-10 20:00:41 -0800366 ocfs2_set_buffer_uptodate(ci, bh);
Mark Fashehccd979b2005-12-15 14:31:24 -0800367 }
Joel Becker8cb471e2009-02-10 20:00:41 -0800368 ocfs2_metadata_cache_io_unlock(ci);
Mark Fashehccd979b2005-12-15 14:31:24 -0800369
Sunil Mushran2bd63212010-01-25 16:57:38 -0800370 mlog(ML_BH_IO, "block=(%llu), nr=(%d), cached=%s, flags=0x%x\n",
Mark Fashehb06970532006-03-03 10:24:33 -0800371 (unsigned long long)block, nr,
Joel Beckerd4a8c932008-10-09 17:20:34 -0700372 ((flags & OCFS2_BH_IGNORE_CACHE) || ignore_cache) ? "no" : "yes",
373 flags);
Mark Fashehccd979b2005-12-15 14:31:24 -0800374
375bail:
376
377 mlog_exit(status);
378 return status;
379}
Tao Mad6590722007-12-18 15:47:03 +0800380
381/* Check whether the blkno is the super block or one of the backups. */
382static void ocfs2_check_super_or_backup(struct super_block *sb,
383 sector_t blkno)
384{
385 int i;
386 u64 backup_blkno;
387
388 if (blkno == OCFS2_SUPER_BLOCK_BLKNO)
389 return;
390
391 for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
392 backup_blkno = ocfs2_backup_super_blkno(sb, i);
393 if (backup_blkno == blkno)
394 return;
395 }
396
397 BUG();
398}
399
400/*
401 * Write super block and backups doesn't need to collaborate with journal,
Joel Becker8cb471e2009-02-10 20:00:41 -0800402 * so we don't need to lock ip_io_mutex and ci doesn't need to bea passed
Tao Mad6590722007-12-18 15:47:03 +0800403 * into this function.
404 */
405int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
406 struct buffer_head *bh)
407{
408 int ret = 0;
Joel Beckera42ab8e2010-03-31 18:25:44 -0700409 struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;
Tao Mad6590722007-12-18 15:47:03 +0800410
411 mlog_entry_void();
412
413 BUG_ON(buffer_jbd(bh));
414 ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr);
415
416 if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) {
417 ret = -EROFS;
418 goto out;
419 }
420
421 lock_buffer(bh);
422 set_buffer_uptodate(bh);
423
424 /* remove from dirty list before I/O. */
425 clear_buffer_dirty(bh);
426
427 get_bh(bh); /* for end_buffer_write_sync() */
428 bh->b_end_io = end_buffer_write_sync;
Joel Beckera42ab8e2010-03-31 18:25:44 -0700429 ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &di->i_check);
Tao Mad6590722007-12-18 15:47:03 +0800430 submit_bh(WRITE, bh);
431
432 wait_on_buffer(bh);
433
434 if (!buffer_uptodate(bh)) {
435 ret = -EIO;
Mark Fasheh2fe5c1d2008-01-23 18:35:31 -0800436 put_bh(bh);
Tao Mad6590722007-12-18 15:47:03 +0800437 }
438
439out:
440 mlog_exit(ret);
441 return ret;
442}