Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * io.c
4 *
5 * Buffer cache handling
6 *
7 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
8 */
9
10#include <linux/fs.h>
11#include <linux/types.h>
12#include <linux/highmem.h>
13#include <linux/bio.h>
14
15#include <cluster/masklog.h>
16
17#include "ocfs2.h"
18
19#include "alloc.h"
20#include "inode.h"
21#include "journal.h"
22#include "uptodate.h"
23#include "buffer_head_io.h"
24#include "ocfs2_trace.h"
25
26/*
27 * Bits on bh->b_state used by ocfs2.
28 *
29 * These MUST be after the JBD2 bits. Hence, we use BH_JBDPrivateStart.
30 */
31enum ocfs2_state_bits {
32 BH_NeedsValidate = BH_JBDPrivateStart,
33};
34
35/* Expand the magic b_state functions */
36BUFFER_FNS(NeedsValidate, needs_validate);
37
38int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
39 struct ocfs2_caching_info *ci)
40{
41 int ret = 0;
42
43 trace_ocfs2_write_block((unsigned long long)bh->b_blocknr, ci);
44
45 BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO);
46 BUG_ON(buffer_jbd(bh));
47
48 /* No need to check for a soft readonly file system here. non
49 * journalled writes are only ever done on system files which
50 * can get modified during recovery even if read-only. */
51 if (ocfs2_is_hard_readonly(osb)) {
52 ret = -EROFS;
53 mlog_errno(ret);
54 goto out;
55 }
56
57 ocfs2_metadata_cache_io_lock(ci);
58
59 lock_buffer(bh);
60 set_buffer_uptodate(bh);
61
62 /* remove from dirty list before I/O. */
63 clear_buffer_dirty(bh);
64
65 get_bh(bh); /* for end_buffer_write_sync() */
66 bh->b_end_io = end_buffer_write_sync;
67 submit_bh(REQ_OP_WRITE, bh);
68
69 wait_on_buffer(bh);
70
71 if (buffer_uptodate(bh)) {
72 ocfs2_set_buffer_uptodate(ci, bh);
73 } else {
74 /* We don't need to remove the clustered uptodate
75 * information for this bh as it's not marked locally
76 * uptodate. */
77 ret = -EIO;
78 mlog_errno(ret);
79 }
80
81 ocfs2_metadata_cache_io_unlock(ci);
82out:
83 return ret;
84}
85
86/* Caller must provide a bhs[] with all NULL or non-NULL entries, so it
87 * will be easier to handle read failure.
88 */
89int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
90 unsigned int nr, struct buffer_head *bhs[])
91{
92 int status = 0;
93 unsigned int i;
94 struct buffer_head *bh;
95 int new_bh = 0;
96
97 trace_ocfs2_read_blocks_sync((unsigned long long)block, nr);
98
99 if (!nr)
100 goto bail;
101
102 /* Don't put buffer head and re-assign it to NULL if it is allocated
103 * outside since the caller can't be aware of this alternation!
104 */
105 new_bh = (bhs[0] == NULL);
106
107 for (i = 0 ; i < nr ; i++) {
108 if (bhs[i] == NULL) {
109 bhs[i] = sb_getblk(osb->sb, block++);
110 if (bhs[i] == NULL) {
111 status = -ENOMEM;
112 mlog_errno(status);
113 break;
114 }
115 }
116 bh = bhs[i];
117
118 if (buffer_jbd(bh)) {
119 trace_ocfs2_read_blocks_sync_jbd(
120 (unsigned long long)bh->b_blocknr);
121 continue;
122 }
123
124 if (buffer_dirty(bh)) {
125 /* This should probably be a BUG, or
126 * at least return an error. */
127 mlog(ML_ERROR,
128 "trying to sync read a dirty "
129 "buffer! (blocknr = %llu), skipping\n",
130 (unsigned long long)bh->b_blocknr);
131 continue;
132 }
133
134 lock_buffer(bh);
135 if (buffer_jbd(bh)) {
136#ifdef CATCH_BH_JBD_RACES
137 mlog(ML_ERROR,
138 "block %llu had the JBD bit set "
139 "while I was in lock_buffer!",
140 (unsigned long long)bh->b_blocknr);
141 BUG();
142#else
143 unlock_buffer(bh);
144 continue;
145#endif
146 }
147
148 get_bh(bh); /* for end_buffer_read_sync() */
149 bh->b_end_io = end_buffer_read_sync;
150 submit_bh(REQ_OP_READ, bh);
151 }
152
153read_failure:
154 for (i = nr; i > 0; i--) {
155 bh = bhs[i - 1];
156
157 if (unlikely(status)) {
158 if (new_bh && bh) {
159 /* If middle bh fails, let previous bh
160 * finish its read and then put it to
161 * avoid bh leak
162 */
163 if (!buffer_jbd(bh))
164 wait_on_buffer(bh);
165 put_bh(bh);
166 bhs[i - 1] = NULL;
167 } else if (bh && buffer_uptodate(bh)) {
168 clear_buffer_uptodate(bh);
169 }
170 continue;
171 }
172
173 /* No need to wait on the buffer if it's managed by JBD. */
174 if (!buffer_jbd(bh))
175 wait_on_buffer(bh);
176
177 if (!buffer_uptodate(bh)) {
178 /* Status won't be cleared from here on out,
179 * so we can safely record this and loop back
180 * to cleanup the other buffers. */
181 status = -EIO;
182 goto read_failure;
183 }
184 }
185
186bail:
187 return status;
188}
189
190/* Caller must provide a bhs[] with all NULL or non-NULL entries, so it
191 * will be easier to handle read failure.
192 */
193int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
194 struct buffer_head *bhs[], int flags,
195 int (*validate)(struct super_block *sb,
196 struct buffer_head *bh))
197{
198 int status = 0;
199 int i, ignore_cache = 0;
200 struct buffer_head *bh;
201 struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
202 int new_bh = 0;
203
204 trace_ocfs2_read_blocks_begin(ci, (unsigned long long)block, nr, flags);
205
206 BUG_ON(!ci);
207 BUG_ON((flags & OCFS2_BH_READAHEAD) &&
208 (flags & OCFS2_BH_IGNORE_CACHE));
209
210 if (bhs == NULL) {
211 status = -EINVAL;
212 mlog_errno(status);
213 goto bail;
214 }
215
216 if (nr < 0) {
217 mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
218 status = -EINVAL;
219 mlog_errno(status);
220 goto bail;
221 }
222
223 if (nr == 0) {
224 status = 0;
225 goto bail;
226 }
227
228 /* Don't put buffer head and re-assign it to NULL if it is allocated
229 * outside since the caller can't be aware of this alternation!
230 */
231 new_bh = (bhs[0] == NULL);
232
233 ocfs2_metadata_cache_io_lock(ci);
234 for (i = 0 ; i < nr ; i++) {
235 if (bhs[i] == NULL) {
236 bhs[i] = sb_getblk(sb, block++);
237 if (bhs[i] == NULL) {
238 ocfs2_metadata_cache_io_unlock(ci);
239 status = -ENOMEM;
240 mlog_errno(status);
241 /* Don't forget to put previous bh! */
242 break;
243 }
244 }
245 bh = bhs[i];
246 ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE);
247
248 /* There are three read-ahead cases here which we need to
249 * be concerned with. All three assume a buffer has
250 * previously been submitted with OCFS2_BH_READAHEAD
251 * and it hasn't yet completed I/O.
252 *
253 * 1) The current request is sync to disk. This rarely
254 * happens these days, and never when performance
255 * matters - the code can just wait on the buffer
256 * lock and re-submit.
257 *
258 * 2) The current request is cached, but not
259 * readahead. ocfs2_buffer_uptodate() will return
260 * false anyway, so we'll wind up waiting on the
261 * buffer lock to do I/O. We re-check the request
262 * with after getting the lock to avoid a re-submit.
263 *
264 * 3) The current request is readahead (and so must
265 * also be a caching one). We short circuit if the
266 * buffer is locked (under I/O) and if it's in the
267 * uptodate cache. The re-check from #2 catches the
268 * case that the previous read-ahead completes just
269 * before our is-it-in-flight check.
270 */
271
272 if (!ignore_cache && !ocfs2_buffer_uptodate(ci, bh)) {
273 trace_ocfs2_read_blocks_from_disk(
274 (unsigned long long)bh->b_blocknr,
275 (unsigned long long)ocfs2_metadata_cache_owner(ci));
276 /* We're using ignore_cache here to say
277 * "go to disk" */
278 ignore_cache = 1;
279 }
280
281 trace_ocfs2_read_blocks_bh((unsigned long long)bh->b_blocknr,
282 ignore_cache, buffer_jbd(bh), buffer_dirty(bh));
283
284 if (buffer_jbd(bh)) {
285 continue;
286 }
287
288 if (ignore_cache) {
289 if (buffer_dirty(bh)) {
290 /* This should probably be a BUG, or
291 * at least return an error. */
292 continue;
293 }
294
295 /* A read-ahead request was made - if the
296 * buffer is already under read-ahead from a
297 * previously submitted request than we are
298 * done here. */
299 if ((flags & OCFS2_BH_READAHEAD)
300 && ocfs2_buffer_read_ahead(ci, bh))
301 continue;
302
303 lock_buffer(bh);
304 if (buffer_jbd(bh)) {
305#ifdef CATCH_BH_JBD_RACES
306 mlog(ML_ERROR, "block %llu had the JBD bit set "
307 "while I was in lock_buffer!",
308 (unsigned long long)bh->b_blocknr);
309 BUG();
310#else
311 unlock_buffer(bh);
312 continue;
313#endif
314 }
315
316 /* Re-check ocfs2_buffer_uptodate() as a
317 * previously read-ahead buffer may have
318 * completed I/O while we were waiting for the
319 * buffer lock. */
320 if (!(flags & OCFS2_BH_IGNORE_CACHE)
321 && !(flags & OCFS2_BH_READAHEAD)
322 && ocfs2_buffer_uptodate(ci, bh)) {
323 unlock_buffer(bh);
324 continue;
325 }
326
327 get_bh(bh); /* for end_buffer_read_sync() */
328 if (validate)
329 set_buffer_needs_validate(bh);
330 bh->b_end_io = end_buffer_read_sync;
331 submit_bh(REQ_OP_READ, bh);
332 continue;
333 }
334 }
335
336read_failure:
337 for (i = (nr - 1); i >= 0; i--) {
338 bh = bhs[i];
339
340 if (!(flags & OCFS2_BH_READAHEAD)) {
341 if (unlikely(status)) {
342 /* Clear the buffers on error including those
343 * ever succeeded in reading
344 */
345 if (new_bh && bh) {
346 /* If middle bh fails, let previous bh
347 * finish its read and then put it to
348 * avoid bh leak
349 */
350 if (!buffer_jbd(bh))
351 wait_on_buffer(bh);
352 put_bh(bh);
353 bhs[i] = NULL;
354 } else if (bh && buffer_uptodate(bh)) {
355 clear_buffer_uptodate(bh);
356 }
357 continue;
358 }
359 /* We know this can't have changed as we hold the
360 * owner sem. Avoid doing any work on the bh if the
361 * journal has it. */
362 if (!buffer_jbd(bh))
363 wait_on_buffer(bh);
364
365 if (!buffer_uptodate(bh)) {
366 /* Status won't be cleared from here on out,
367 * so we can safely record this and loop back
368 * to cleanup the other buffers. Don't need to
369 * remove the clustered uptodate information
370 * for this bh as it's not marked locally
371 * uptodate. */
372 status = -EIO;
373 clear_buffer_needs_validate(bh);
374 goto read_failure;
375 }
376
377 if (buffer_needs_validate(bh)) {
378 /* We never set NeedsValidate if the
379 * buffer was held by the journal, so
380 * that better not have changed */
381 BUG_ON(buffer_jbd(bh));
382 clear_buffer_needs_validate(bh);
383 status = validate(sb, bh);
384 if (status)
385 goto read_failure;
386 }
387 }
388
389 /* Always set the buffer in the cache, even if it was
390 * a forced read, or read-ahead which hasn't yet
391 * completed. */
392 ocfs2_set_buffer_uptodate(ci, bh);
393 }
394 ocfs2_metadata_cache_io_unlock(ci);
395
396 trace_ocfs2_read_blocks_end((unsigned long long)block, nr,
397 flags, ignore_cache);
398
399bail:
400
401 return status;
402}
403
404/* Check whether the blkno is the super block or one of the backups. */
405static void ocfs2_check_super_or_backup(struct super_block *sb,
406 sector_t blkno)
407{
408 int i;
409 u64 backup_blkno;
410
411 if (blkno == OCFS2_SUPER_BLOCK_BLKNO)
412 return;
413
414 for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
415 backup_blkno = ocfs2_backup_super_blkno(sb, i);
416 if (backup_blkno == blkno)
417 return;
418 }
419
420 BUG();
421}
422
423/*
424 * Write super block and backups doesn't need to collaborate with journal,
425 * so we don't need to lock ip_io_mutex and ci doesn't need to bea passed
426 * into this function.
427 */
428int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
429 struct buffer_head *bh)
430{
431 int ret = 0;
432 struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;
433
434 BUG_ON(buffer_jbd(bh));
435 ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr);
436
437 if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) {
438 ret = -EROFS;
439 mlog_errno(ret);
440 goto out;
441 }
442
443 lock_buffer(bh);
444 set_buffer_uptodate(bh);
445
446 /* remove from dirty list before I/O. */
447 clear_buffer_dirty(bh);
448
449 get_bh(bh); /* for end_buffer_write_sync() */
450 bh->b_end_io = end_buffer_write_sync;
451 ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &di->i_check);
452 submit_bh(REQ_OP_WRITE, bh);
453
454 wait_on_buffer(bh);
455
456 if (!buffer_uptodate(bh)) {
457 ret = -EIO;
458 mlog_errno(ret);
459 }
460
461out:
462 return ret;
463}
1/* -*- 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/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#include "buffer_head_io.h"
39#include "ocfs2_trace.h"
40
41/*
42 * Bits on bh->b_state used by ocfs2.
43 *
44 * These MUST be after the JBD2 bits. Hence, we use BH_JBDPrivateStart.
45 */
46enum ocfs2_state_bits {
47 BH_NeedsValidate = BH_JBDPrivateStart,
48};
49
50/* Expand the magic b_state functions */
51BUFFER_FNS(NeedsValidate, needs_validate);
52
53int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
54 struct ocfs2_caching_info *ci)
55{
56 int ret = 0;
57
58 trace_ocfs2_write_block((unsigned long long)bh->b_blocknr, ci);
59
60 BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO);
61 BUG_ON(buffer_jbd(bh));
62
63 /* No need to check for a soft readonly file system here. non
64 * journalled writes are only ever done on system files which
65 * can get modified during recovery even if read-only. */
66 if (ocfs2_is_hard_readonly(osb)) {
67 ret = -EROFS;
68 mlog_errno(ret);
69 goto out;
70 }
71
72 ocfs2_metadata_cache_io_lock(ci);
73
74 lock_buffer(bh);
75 set_buffer_uptodate(bh);
76
77 /* remove from dirty list before I/O. */
78 clear_buffer_dirty(bh);
79
80 get_bh(bh); /* for end_buffer_write_sync() */
81 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)) {
87 ocfs2_set_buffer_uptodate(ci, bh);
88 } 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;
93 put_bh(bh);
94 mlog_errno(ret);
95 }
96
97 ocfs2_metadata_cache_io_unlock(ci);
98out:
99 return ret;
100}
101
102int 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 trace_ocfs2_read_blocks_sync((unsigned long long)block, nr);
110
111 if (!nr)
112 goto bail;
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)) {
126 trace_ocfs2_read_blocks_sync_jbd(
127 (unsigned long long)bh->b_blocknr);
128 continue;
129 }
130
131 if (buffer_dirty(bh)) {
132 /* This should probably be a BUG, or
133 * at least return an error. */
134 mlog(ML_ERROR,
135 "trying to sync read a dirty "
136 "buffer! (blocknr = %llu), skipping\n",
137 (unsigned long long)bh->b_blocknr);
138 continue;
139 }
140
141 lock_buffer(bh);
142 if (buffer_jbd(bh)) {
143 mlog(ML_ERROR,
144 "block %llu had the JBD bit set "
145 "while I was in lock_buffer!",
146 (unsigned long long)bh->b_blocknr);
147 BUG();
148 }
149
150 clear_buffer_uptodate(bh);
151 get_bh(bh); /* for end_buffer_read_sync() */
152 bh->b_end_io = end_buffer_read_sync;
153 submit_bh(READ, bh);
154 }
155
156 for (i = nr; i > 0; i--) {
157 bh = bhs[i - 1];
158
159 /* No need to wait on the buffer if it's managed by JBD. */
160 if (!buffer_jbd(bh))
161 wait_on_buffer(bh);
162
163 if (!buffer_uptodate(bh)) {
164 /* Status won't be cleared from here on out,
165 * so we can safely record this and loop back
166 * to cleanup the other buffers. */
167 status = -EIO;
168 put_bh(bh);
169 bhs[i - 1] = NULL;
170 }
171 }
172
173bail:
174 return status;
175}
176
177int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
178 struct buffer_head *bhs[], int flags,
179 int (*validate)(struct super_block *sb,
180 struct buffer_head *bh))
181{
182 int status = 0;
183 int i, ignore_cache = 0;
184 struct buffer_head *bh;
185 struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
186
187 trace_ocfs2_read_blocks_begin(ci, (unsigned long long)block, nr, flags);
188
189 BUG_ON(!ci);
190 BUG_ON((flags & OCFS2_BH_READAHEAD) &&
191 (flags & OCFS2_BH_IGNORE_CACHE));
192
193 if (bhs == NULL) {
194 status = -EINVAL;
195 mlog_errno(status);
196 goto bail;
197 }
198
199 if (nr < 0) {
200 mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
201 status = -EINVAL;
202 mlog_errno(status);
203 goto bail;
204 }
205
206 if (nr == 0) {
207 status = 0;
208 goto bail;
209 }
210
211 ocfs2_metadata_cache_io_lock(ci);
212 for (i = 0 ; i < nr ; i++) {
213 if (bhs[i] == NULL) {
214 bhs[i] = sb_getblk(sb, block++);
215 if (bhs[i] == NULL) {
216 ocfs2_metadata_cache_io_unlock(ci);
217 status = -EIO;
218 mlog_errno(status);
219 goto bail;
220 }
221 }
222 bh = bhs[i];
223 ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE);
224
225 /* There are three read-ahead cases here which we need to
226 * be concerned with. All three assume a buffer has
227 * previously been submitted with OCFS2_BH_READAHEAD
228 * and it hasn't yet completed I/O.
229 *
230 * 1) The current request is sync to disk. This rarely
231 * happens these days, and never when performance
232 * matters - the code can just wait on the buffer
233 * lock and re-submit.
234 *
235 * 2) The current request is cached, but not
236 * readahead. ocfs2_buffer_uptodate() will return
237 * false anyway, so we'll wind up waiting on the
238 * buffer lock to do I/O. We re-check the request
239 * with after getting the lock to avoid a re-submit.
240 *
241 * 3) The current request is readahead (and so must
242 * also be a caching one). We short circuit if the
243 * buffer is locked (under I/O) and if it's in the
244 * uptodate cache. The re-check from #2 catches the
245 * case that the previous read-ahead completes just
246 * before our is-it-in-flight check.
247 */
248
249 if (!ignore_cache && !ocfs2_buffer_uptodate(ci, bh)) {
250 trace_ocfs2_read_blocks_from_disk(
251 (unsigned long long)bh->b_blocknr,
252 (unsigned long long)ocfs2_metadata_cache_owner(ci));
253 /* We're using ignore_cache here to say
254 * "go to disk" */
255 ignore_cache = 1;
256 }
257
258 trace_ocfs2_read_blocks_bh((unsigned long long)bh->b_blocknr,
259 ignore_cache, buffer_jbd(bh), buffer_dirty(bh));
260
261 if (buffer_jbd(bh)) {
262 continue;
263 }
264
265 if (ignore_cache) {
266 if (buffer_dirty(bh)) {
267 /* This should probably be a BUG, or
268 * at least return an error. */
269 continue;
270 }
271
272 /* A read-ahead request was made - if the
273 * buffer is already under read-ahead from a
274 * previously submitted request than we are
275 * done here. */
276 if ((flags & OCFS2_BH_READAHEAD)
277 && ocfs2_buffer_read_ahead(ci, bh))
278 continue;
279
280 lock_buffer(bh);
281 if (buffer_jbd(bh)) {
282#ifdef CATCH_BH_JBD_RACES
283 mlog(ML_ERROR, "block %llu had the JBD bit set "
284 "while I was in lock_buffer!",
285 (unsigned long long)bh->b_blocknr);
286 BUG();
287#else
288 unlock_buffer(bh);
289 continue;
290#endif
291 }
292
293 /* Re-check ocfs2_buffer_uptodate() as a
294 * previously read-ahead buffer may have
295 * completed I/O while we were waiting for the
296 * buffer lock. */
297 if (!(flags & OCFS2_BH_IGNORE_CACHE)
298 && !(flags & OCFS2_BH_READAHEAD)
299 && ocfs2_buffer_uptodate(ci, bh)) {
300 unlock_buffer(bh);
301 continue;
302 }
303
304 clear_buffer_uptodate(bh);
305 get_bh(bh); /* for end_buffer_read_sync() */
306 if (validate)
307 set_buffer_needs_validate(bh);
308 bh->b_end_io = end_buffer_read_sync;
309 submit_bh(READ, bh);
310 continue;
311 }
312 }
313
314 status = 0;
315
316 for (i = (nr - 1); i >= 0; i--) {
317 bh = bhs[i];
318
319 if (!(flags & OCFS2_BH_READAHEAD)) {
320 /* We know this can't have changed as we hold the
321 * owner sem. Avoid doing any work on the bh if the
322 * journal has it. */
323 if (!buffer_jbd(bh))
324 wait_on_buffer(bh);
325
326 if (!buffer_uptodate(bh)) {
327 /* Status won't be cleared from here on out,
328 * so we can safely record this and loop back
329 * to cleanup the other buffers. Don't need to
330 * remove the clustered uptodate information
331 * for this bh as it's not marked locally
332 * uptodate. */
333 status = -EIO;
334 put_bh(bh);
335 bhs[i] = NULL;
336 continue;
337 }
338
339 if (buffer_needs_validate(bh)) {
340 /* We never set NeedsValidate if the
341 * buffer was held by the journal, so
342 * that better not have changed */
343 BUG_ON(buffer_jbd(bh));
344 clear_buffer_needs_validate(bh);
345 status = validate(sb, bh);
346 if (status) {
347 put_bh(bh);
348 bhs[i] = NULL;
349 continue;
350 }
351 }
352 }
353
354 /* Always set the buffer in the cache, even if it was
355 * a forced read, or read-ahead which hasn't yet
356 * completed. */
357 ocfs2_set_buffer_uptodate(ci, bh);
358 }
359 ocfs2_metadata_cache_io_unlock(ci);
360
361 trace_ocfs2_read_blocks_end((unsigned long long)block, nr,
362 flags, ignore_cache);
363
364bail:
365
366 return status;
367}
368
369/* Check whether the blkno is the super block or one of the backups. */
370static void ocfs2_check_super_or_backup(struct super_block *sb,
371 sector_t blkno)
372{
373 int i;
374 u64 backup_blkno;
375
376 if (blkno == OCFS2_SUPER_BLOCK_BLKNO)
377 return;
378
379 for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
380 backup_blkno = ocfs2_backup_super_blkno(sb, i);
381 if (backup_blkno == blkno)
382 return;
383 }
384
385 BUG();
386}
387
388/*
389 * Write super block and backups doesn't need to collaborate with journal,
390 * so we don't need to lock ip_io_mutex and ci doesn't need to bea passed
391 * into this function.
392 */
393int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
394 struct buffer_head *bh)
395{
396 int ret = 0;
397 struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;
398
399 BUG_ON(buffer_jbd(bh));
400 ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr);
401
402 if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) {
403 ret = -EROFS;
404 mlog_errno(ret);
405 goto out;
406 }
407
408 lock_buffer(bh);
409 set_buffer_uptodate(bh);
410
411 /* remove from dirty list before I/O. */
412 clear_buffer_dirty(bh);
413
414 get_bh(bh); /* for end_buffer_write_sync() */
415 bh->b_end_io = end_buffer_write_sync;
416 ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &di->i_check);
417 submit_bh(WRITE, bh);
418
419 wait_on_buffer(bh);
420
421 if (!buffer_uptodate(bh)) {
422 ret = -EIO;
423 put_bh(bh);
424 mlog_errno(ret);
425 }
426
427out:
428 return ret;
429}