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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}
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#include <linux/bio.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#include "buffer_head_io.h"
40#include "ocfs2_trace.h"
41
42/*
43 * Bits on bh->b_state used by ocfs2.
44 *
45 * These MUST be after the JBD2 bits. Hence, we use BH_JBDPrivateStart.
46 */
47enum ocfs2_state_bits {
48 BH_NeedsValidate = BH_JBDPrivateStart,
49};
50
51/* Expand the magic b_state functions */
52BUFFER_FNS(NeedsValidate, needs_validate);
53
54int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
55 struct ocfs2_caching_info *ci)
56{
57 int ret = 0;
58
59 trace_ocfs2_write_block((unsigned long long)bh->b_blocknr, ci);
60
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 mlog_errno(ret);
70 goto out;
71 }
72
73 ocfs2_metadata_cache_io_lock(ci);
74
75 lock_buffer(bh);
76 set_buffer_uptodate(bh);
77
78 /* remove from dirty list before I/O. */
79 clear_buffer_dirty(bh);
80
81 get_bh(bh); /* for end_buffer_write_sync() */
82 bh->b_end_io = end_buffer_write_sync;
83 submit_bh(REQ_OP_WRITE, 0, bh);
84
85 wait_on_buffer(bh);
86
87 if (buffer_uptodate(bh)) {
88 ocfs2_set_buffer_uptodate(ci, bh);
89 } else {
90 /* We don't need to remove the clustered uptodate
91 * information for this bh as it's not marked locally
92 * uptodate. */
93 ret = -EIO;
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 = -ENOMEM;
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#ifdef CATCH_BH_JBD_RACES
144 mlog(ML_ERROR,
145 "block %llu had the JBD bit set "
146 "while I was in lock_buffer!",
147 (unsigned long long)bh->b_blocknr);
148 BUG();
149#else
150 unlock_buffer(bh);
151 continue;
152#endif
153 }
154
155 clear_buffer_uptodate(bh);
156 get_bh(bh); /* for end_buffer_read_sync() */
157 bh->b_end_io = end_buffer_read_sync;
158 submit_bh(REQ_OP_READ, 0, bh);
159 }
160
161 for (i = nr; i > 0; i--) {
162 bh = bhs[i - 1];
163
164 /* No need to wait on the buffer if it's managed by JBD. */
165 if (!buffer_jbd(bh))
166 wait_on_buffer(bh);
167
168 if (!buffer_uptodate(bh)) {
169 /* Status won't be cleared from here on out,
170 * so we can safely record this and loop back
171 * to cleanup the other buffers. */
172 status = -EIO;
173 put_bh(bh);
174 bhs[i - 1] = NULL;
175 }
176 }
177
178bail:
179 return status;
180}
181
182int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
183 struct buffer_head *bhs[], int flags,
184 int (*validate)(struct super_block *sb,
185 struct buffer_head *bh))
186{
187 int status = 0;
188 int i, ignore_cache = 0;
189 struct buffer_head *bh;
190 struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
191
192 trace_ocfs2_read_blocks_begin(ci, (unsigned long long)block, nr, flags);
193
194 BUG_ON(!ci);
195 BUG_ON((flags & OCFS2_BH_READAHEAD) &&
196 (flags & OCFS2_BH_IGNORE_CACHE));
197
198 if (bhs == NULL) {
199 status = -EINVAL;
200 mlog_errno(status);
201 goto bail;
202 }
203
204 if (nr < 0) {
205 mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
206 status = -EINVAL;
207 mlog_errno(status);
208 goto bail;
209 }
210
211 if (nr == 0) {
212 status = 0;
213 goto bail;
214 }
215
216 ocfs2_metadata_cache_io_lock(ci);
217 for (i = 0 ; i < nr ; i++) {
218 if (bhs[i] == NULL) {
219 bhs[i] = sb_getblk(sb, block++);
220 if (bhs[i] == NULL) {
221 ocfs2_metadata_cache_io_unlock(ci);
222 status = -ENOMEM;
223 mlog_errno(status);
224 goto bail;
225 }
226 }
227 bh = bhs[i];
228 ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE);
229
230 /* There are three read-ahead cases here which we need to
231 * be concerned with. All three assume a buffer has
232 * previously been submitted with OCFS2_BH_READAHEAD
233 * and it hasn't yet completed I/O.
234 *
235 * 1) The current request is sync to disk. This rarely
236 * happens these days, and never when performance
237 * matters - the code can just wait on the buffer
238 * lock and re-submit.
239 *
240 * 2) The current request is cached, but not
241 * readahead. ocfs2_buffer_uptodate() will return
242 * false anyway, so we'll wind up waiting on the
243 * buffer lock to do I/O. We re-check the request
244 * with after getting the lock to avoid a re-submit.
245 *
246 * 3) The current request is readahead (and so must
247 * also be a caching one). We short circuit if the
248 * buffer is locked (under I/O) and if it's in the
249 * uptodate cache. The re-check from #2 catches the
250 * case that the previous read-ahead completes just
251 * before our is-it-in-flight check.
252 */
253
254 if (!ignore_cache && !ocfs2_buffer_uptodate(ci, bh)) {
255 trace_ocfs2_read_blocks_from_disk(
256 (unsigned long long)bh->b_blocknr,
257 (unsigned long long)ocfs2_metadata_cache_owner(ci));
258 /* We're using ignore_cache here to say
259 * "go to disk" */
260 ignore_cache = 1;
261 }
262
263 trace_ocfs2_read_blocks_bh((unsigned long long)bh->b_blocknr,
264 ignore_cache, buffer_jbd(bh), buffer_dirty(bh));
265
266 if (buffer_jbd(bh)) {
267 continue;
268 }
269
270 if (ignore_cache) {
271 if (buffer_dirty(bh)) {
272 /* This should probably be a BUG, or
273 * at least return an error. */
274 continue;
275 }
276
277 /* A read-ahead request was made - if the
278 * buffer is already under read-ahead from a
279 * previously submitted request than we are
280 * done here. */
281 if ((flags & OCFS2_BH_READAHEAD)
282 && ocfs2_buffer_read_ahead(ci, bh))
283 continue;
284
285 lock_buffer(bh);
286 if (buffer_jbd(bh)) {
287#ifdef CATCH_BH_JBD_RACES
288 mlog(ML_ERROR, "block %llu had the JBD bit set "
289 "while I was in lock_buffer!",
290 (unsigned long long)bh->b_blocknr);
291 BUG();
292#else
293 unlock_buffer(bh);
294 continue;
295#endif
296 }
297
298 /* Re-check ocfs2_buffer_uptodate() as a
299 * previously read-ahead buffer may have
300 * completed I/O while we were waiting for the
301 * buffer lock. */
302 if (!(flags & OCFS2_BH_IGNORE_CACHE)
303 && !(flags & OCFS2_BH_READAHEAD)
304 && ocfs2_buffer_uptodate(ci, bh)) {
305 unlock_buffer(bh);
306 continue;
307 }
308
309 clear_buffer_uptodate(bh);
310 get_bh(bh); /* for end_buffer_read_sync() */
311 if (validate)
312 set_buffer_needs_validate(bh);
313 bh->b_end_io = end_buffer_read_sync;
314 submit_bh(REQ_OP_READ, 0, bh);
315 continue;
316 }
317 }
318
319 status = 0;
320
321 for (i = (nr - 1); i >= 0; i--) {
322 bh = bhs[i];
323
324 if (!(flags & OCFS2_BH_READAHEAD)) {
325 if (status) {
326 /* Clear the rest of the buffers on error */
327 put_bh(bh);
328 bhs[i] = NULL;
329 continue;
330 }
331 /* We know this can't have changed as we hold the
332 * owner sem. Avoid doing any work on the bh if the
333 * journal has it. */
334 if (!buffer_jbd(bh))
335 wait_on_buffer(bh);
336
337 if (!buffer_uptodate(bh)) {
338 /* Status won't be cleared from here on out,
339 * so we can safely record this and loop back
340 * to cleanup the other buffers. Don't need to
341 * remove the clustered uptodate information
342 * for this bh as it's not marked locally
343 * uptodate. */
344 status = -EIO;
345 put_bh(bh);
346 bhs[i] = NULL;
347 continue;
348 }
349
350 if (buffer_needs_validate(bh)) {
351 /* We never set NeedsValidate if the
352 * buffer was held by the journal, so
353 * that better not have changed */
354 BUG_ON(buffer_jbd(bh));
355 clear_buffer_needs_validate(bh);
356 status = validate(sb, bh);
357 if (status) {
358 put_bh(bh);
359 bhs[i] = NULL;
360 continue;
361 }
362 }
363 }
364
365 /* Always set the buffer in the cache, even if it was
366 * a forced read, or read-ahead which hasn't yet
367 * completed. */
368 ocfs2_set_buffer_uptodate(ci, bh);
369 }
370 ocfs2_metadata_cache_io_unlock(ci);
371
372 trace_ocfs2_read_blocks_end((unsigned long long)block, nr,
373 flags, ignore_cache);
374
375bail:
376
377 return status;
378}
379
380/* Check whether the blkno is the super block or one of the backups. */
381static void ocfs2_check_super_or_backup(struct super_block *sb,
382 sector_t blkno)
383{
384 int i;
385 u64 backup_blkno;
386
387 if (blkno == OCFS2_SUPER_BLOCK_BLKNO)
388 return;
389
390 for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
391 backup_blkno = ocfs2_backup_super_blkno(sb, i);
392 if (backup_blkno == blkno)
393 return;
394 }
395
396 BUG();
397}
398
399/*
400 * Write super block and backups doesn't need to collaborate with journal,
401 * so we don't need to lock ip_io_mutex and ci doesn't need to bea passed
402 * into this function.
403 */
404int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
405 struct buffer_head *bh)
406{
407 int ret = 0;
408 struct ocfs2_dinode *di = (struct ocfs2_dinode *)bh->b_data;
409
410 BUG_ON(buffer_jbd(bh));
411 ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr);
412
413 if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) {
414 ret = -EROFS;
415 mlog_errno(ret);
416 goto out;
417 }
418
419 lock_buffer(bh);
420 set_buffer_uptodate(bh);
421
422 /* remove from dirty list before I/O. */
423 clear_buffer_dirty(bh);
424
425 get_bh(bh); /* for end_buffer_write_sync() */
426 bh->b_end_io = end_buffer_write_sync;
427 ocfs2_compute_meta_ecc(osb->sb, bh->b_data, &di->i_check);
428 submit_bh(REQ_OP_WRITE, 0, bh);
429
430 wait_on_buffer(bh);
431
432 if (!buffer_uptodate(bh)) {
433 ret = -EIO;
434 mlog_errno(ret);
435 }
436
437out:
438 return ret;
439}