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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 mlog_errno(ret);
94 }
95
96 ocfs2_metadata_cache_io_unlock(ci);
97out:
98 return ret;
99}
100
101int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
102 unsigned int nr, struct buffer_head *bhs[])
103{
104 int status = 0;
105 unsigned int i;
106 struct buffer_head *bh;
107
108 trace_ocfs2_read_blocks_sync((unsigned long long)block, nr);
109
110 if (!nr)
111 goto bail;
112
113 for (i = 0 ; i < nr ; i++) {
114 if (bhs[i] == NULL) {
115 bhs[i] = sb_getblk(osb->sb, block++);
116 if (bhs[i] == NULL) {
117 status = -ENOMEM;
118 mlog_errno(status);
119 goto bail;
120 }
121 }
122 bh = bhs[i];
123
124 if (buffer_jbd(bh)) {
125 trace_ocfs2_read_blocks_sync_jbd(
126 (unsigned long long)bh->b_blocknr);
127 continue;
128 }
129
130 if (buffer_dirty(bh)) {
131 /* This should probably be a BUG, or
132 * at least return an error. */
133 mlog(ML_ERROR,
134 "trying to sync read a dirty "
135 "buffer! (blocknr = %llu), skipping\n",
136 (unsigned long long)bh->b_blocknr);
137 continue;
138 }
139
140 lock_buffer(bh);
141 if (buffer_jbd(bh)) {
142 mlog(ML_ERROR,
143 "block %llu had the JBD bit set "
144 "while I was in lock_buffer!",
145 (unsigned long long)bh->b_blocknr);
146 BUG();
147 }
148
149 clear_buffer_uptodate(bh);
150 get_bh(bh); /* for end_buffer_read_sync() */
151 bh->b_end_io = end_buffer_read_sync;
152 submit_bh(READ, bh);
153 }
154
155 for (i = nr; i > 0; i--) {
156 bh = bhs[i - 1];
157
158 /* No need to wait on the buffer if it's managed by JBD. */
159 if (!buffer_jbd(bh))
160 wait_on_buffer(bh);
161
162 if (!buffer_uptodate(bh)) {
163 /* Status won't be cleared from here on out,
164 * so we can safely record this and loop back
165 * to cleanup the other buffers. */
166 status = -EIO;
167 put_bh(bh);
168 bhs[i - 1] = NULL;
169 }
170 }
171
172bail:
173 return status;
174}
175
176int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
177 struct buffer_head *bhs[], int flags,
178 int (*validate)(struct super_block *sb,
179 struct buffer_head *bh))
180{
181 int status = 0;
182 int i, ignore_cache = 0;
183 struct buffer_head *bh;
184 struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
185
186 trace_ocfs2_read_blocks_begin(ci, (unsigned long long)block, nr, flags);
187
188 BUG_ON(!ci);
189 BUG_ON((flags & OCFS2_BH_READAHEAD) &&
190 (flags & OCFS2_BH_IGNORE_CACHE));
191
192 if (bhs == NULL) {
193 status = -EINVAL;
194 mlog_errno(status);
195 goto bail;
196 }
197
198 if (nr < 0) {
199 mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
200 status = -EINVAL;
201 mlog_errno(status);
202 goto bail;
203 }
204
205 if (nr == 0) {
206 status = 0;
207 goto bail;
208 }
209
210 ocfs2_metadata_cache_io_lock(ci);
211 for (i = 0 ; i < nr ; i++) {
212 if (bhs[i] == NULL) {
213 bhs[i] = sb_getblk(sb, block++);
214 if (bhs[i] == NULL) {
215 ocfs2_metadata_cache_io_unlock(ci);
216 status = -ENOMEM;
217 mlog_errno(status);
218 goto bail;
219 }
220 }
221 bh = bhs[i];
222 ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE);
223
224 /* There are three read-ahead cases here which we need to
225 * be concerned with. All three assume a buffer has
226 * previously been submitted with OCFS2_BH_READAHEAD
227 * and it hasn't yet completed I/O.
228 *
229 * 1) The current request is sync to disk. This rarely
230 * happens these days, and never when performance
231 * matters - the code can just wait on the buffer
232 * lock and re-submit.
233 *
234 * 2) The current request is cached, but not
235 * readahead. ocfs2_buffer_uptodate() will return
236 * false anyway, so we'll wind up waiting on the
237 * buffer lock to do I/O. We re-check the request
238 * with after getting the lock to avoid a re-submit.
239 *
240 * 3) The current request is readahead (and so must
241 * also be a caching one). We short circuit if the
242 * buffer is locked (under I/O) and if it's in the
243 * uptodate cache. The re-check from #2 catches the
244 * case that the previous read-ahead completes just
245 * before our is-it-in-flight check.
246 */
247
248 if (!ignore_cache && !ocfs2_buffer_uptodate(ci, bh)) {
249 trace_ocfs2_read_blocks_from_disk(
250 (unsigned long long)bh->b_blocknr,
251 (unsigned long long)ocfs2_metadata_cache_owner(ci));
252 /* We're using ignore_cache here to say
253 * "go to disk" */
254 ignore_cache = 1;
255 }
256
257 trace_ocfs2_read_blocks_bh((unsigned long long)bh->b_blocknr,
258 ignore_cache, buffer_jbd(bh), buffer_dirty(bh));
259
260 if (buffer_jbd(bh)) {
261 continue;
262 }
263
264 if (ignore_cache) {
265 if (buffer_dirty(bh)) {
266 /* This should probably be a BUG, or
267 * at least return an error. */
268 continue;
269 }
270
271 /* A read-ahead request was made - if the
272 * buffer is already under read-ahead from a
273 * previously submitted request than we are
274 * done here. */
275 if ((flags & OCFS2_BH_READAHEAD)
276 && ocfs2_buffer_read_ahead(ci, bh))
277 continue;
278
279 lock_buffer(bh);
280 if (buffer_jbd(bh)) {
281#ifdef CATCH_BH_JBD_RACES
282 mlog(ML_ERROR, "block %llu had the JBD bit set "
283 "while I was in lock_buffer!",
284 (unsigned long long)bh->b_blocknr);
285 BUG();
286#else
287 unlock_buffer(bh);
288 continue;
289#endif
290 }
291
292 /* Re-check ocfs2_buffer_uptodate() as a
293 * previously read-ahead buffer may have
294 * completed I/O while we were waiting for the
295 * buffer lock. */
296 if (!(flags & OCFS2_BH_IGNORE_CACHE)
297 && !(flags & OCFS2_BH_READAHEAD)
298 && ocfs2_buffer_uptodate(ci, bh)) {
299 unlock_buffer(bh);
300 continue;
301 }
302
303 clear_buffer_uptodate(bh);
304 get_bh(bh); /* for end_buffer_read_sync() */
305 if (validate)
306 set_buffer_needs_validate(bh);
307 bh->b_end_io = end_buffer_read_sync;
308 submit_bh(READ, bh);
309 continue;
310 }
311 }
312
313 status = 0;
314
315 for (i = (nr - 1); i >= 0; i--) {
316 bh = bhs[i];
317
318 if (!(flags & OCFS2_BH_READAHEAD)) {
319 if (status) {
320 /* Clear the rest of the buffers on error */
321 put_bh(bh);
322 bhs[i] = NULL;
323 continue;
324 }
325 /* We know this can't have changed as we hold the
326 * owner sem. Avoid doing any work on the bh if the
327 * journal has it. */
328 if (!buffer_jbd(bh))
329 wait_on_buffer(bh);
330
331 if (!buffer_uptodate(bh)) {
332 /* Status won't be cleared from here on out,
333 * so we can safely record this and loop back
334 * to cleanup the other buffers. Don't need to
335 * remove the clustered uptodate information
336 * for this bh as it's not marked locally
337 * uptodate. */
338 status = -EIO;
339 put_bh(bh);
340 bhs[i] = NULL;
341 continue;
342 }
343
344 if (buffer_needs_validate(bh)) {
345 /* We never set NeedsValidate if the
346 * buffer was held by the journal, so
347 * that better not have changed */
348 BUG_ON(buffer_jbd(bh));
349 clear_buffer_needs_validate(bh);
350 status = validate(sb, bh);
351 if (status) {
352 put_bh(bh);
353 bhs[i] = NULL;
354 continue;
355 }
356 }
357 }
358
359 /* Always set the buffer in the cache, even if it was
360 * a forced read, or read-ahead which hasn't yet
361 * completed. */
362 ocfs2_set_buffer_uptodate(ci, bh);
363 }
364 ocfs2_metadata_cache_io_unlock(ci);
365
366 trace_ocfs2_read_blocks_end((unsigned long long)block, nr,
367 flags, ignore_cache);
368
369bail:
370
371 return status;
372}
373
374/* Check whether the blkno is the super block or one of the backups. */
375static void ocfs2_check_super_or_backup(struct super_block *sb,
376 sector_t blkno)
377{
378 int i;
379 u64 backup_blkno;
380
381 if (blkno == OCFS2_SUPER_BLOCK_BLKNO)
382 return;
383
384 for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
385 backup_blkno = ocfs2_backup_super_blkno(sb, i);
386 if (backup_blkno == blkno)
387 return;
388 }
389
390 BUG();
391}
392
393/*
394 * Write super block and backups doesn't need to collaborate with journal,
395 * so we don't need to lock ip_io_mutex and ci doesn't need to bea passed
396 * into this function.
397 */
398int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
399 struct buffer_head *bh)
400{
401 int ret = 0;
402 struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;
403
404 BUG_ON(buffer_jbd(bh));
405 ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr);
406
407 if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) {
408 ret = -EROFS;
409 mlog_errno(ret);
410 goto out;
411 }
412
413 lock_buffer(bh);
414 set_buffer_uptodate(bh);
415
416 /* remove from dirty list before I/O. */
417 clear_buffer_dirty(bh);
418
419 get_bh(bh); /* for end_buffer_write_sync() */
420 bh->b_end_io = end_buffer_write_sync;
421 ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &di->i_check);
422 submit_bh(WRITE, bh);
423
424 wait_on_buffer(bh);
425
426 if (!buffer_uptodate(bh)) {
427 ret = -EIO;
428 mlog_errno(ret);
429 }
430
431out:
432 return ret;
433}