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ccd979bd MF |
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/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 | ||
42 | int 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 | ||
251b6ecc | 61 | mutex_lock(&OCFS2_I(inode)->ip_io_mutex); |
ccd979bd MF |
62 | |
63 | lock_buffer(bh); | |
64 | set_buffer_uptodate(bh); | |
65 | ||
66 | /* remove from dirty list before I/O. */ | |
67 | clear_buffer_dirty(bh); | |
68 | ||
da1e9098 | 69 | get_bh(bh); /* for end_buffer_write_sync() */ |
ccd979bd MF |
70 | 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; | |
2fe5c1d7 | 82 | put_bh(bh); |
ccd979bd MF |
83 | } |
84 | ||
251b6ecc | 85 | mutex_unlock(&OCFS2_I(inode)->ip_io_mutex); |
ccd979bd MF |
86 | out: |
87 | mlog_exit(ret); | |
88 | return ret; | |
89 | } | |
90 | ||
da1e9098 JB |
91 | int 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)) { | |
d6b58f89 | 115 | mlog(ML_BH_IO, |
da1e9098 JB |
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 | ||
d6b58f89 MF |
150 | /* No need to wait on the buffer if it's managed by JBD. */ |
151 | if (!buffer_jbd(bh)) | |
152 | wait_on_buffer(bh); | |
da1e9098 | 153 | |
da1e9098 JB |
154 | if (!buffer_uptodate(bh)) { |
155 | /* Status won't be cleared from here on out, | |
156 | * so we can safely record this and loop back | |
157 | * to cleanup the other buffers. */ | |
158 | status = -EIO; | |
159 | put_bh(bh); | |
160 | bhs[i - 1] = NULL; | |
161 | } | |
162 | } | |
163 | ||
164 | bail: | |
165 | return status; | |
166 | } | |
167 | ||
31d33073 JB |
168 | int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, |
169 | struct buffer_head *bhs[], int flags) | |
ccd979bd MF |
170 | { |
171 | int status = 0; | |
ccd979bd MF |
172 | int i, ignore_cache = 0; |
173 | struct buffer_head *bh; | |
174 | ||
31d33073 JB |
175 | mlog_entry("(inode=%p, block=(%llu), nr=(%d), flags=%d)\n", |
176 | inode, (unsigned long long)block, nr, flags); | |
ccd979bd | 177 | |
31d33073 | 178 | BUG_ON(!inode); |
d4a8c93c JB |
179 | BUG_ON((flags & OCFS2_BH_READAHEAD) && |
180 | (flags & OCFS2_BH_IGNORE_CACHE)); | |
aa958874 | 181 | |
31d33073 | 182 | if (bhs == NULL) { |
ccd979bd MF |
183 | status = -EINVAL; |
184 | mlog_errno(status); | |
185 | goto bail; | |
186 | } | |
187 | ||
188 | if (nr < 0) { | |
189 | mlog(ML_ERROR, "asked to read %d blocks!\n", nr); | |
190 | status = -EINVAL; | |
191 | mlog_errno(status); | |
192 | goto bail; | |
193 | } | |
194 | ||
195 | if (nr == 0) { | |
196 | mlog(ML_BH_IO, "No buffers will be read!\n"); | |
197 | status = 0; | |
198 | goto bail; | |
199 | } | |
200 | ||
31d33073 | 201 | mutex_lock(&OCFS2_I(inode)->ip_io_mutex); |
ccd979bd MF |
202 | for (i = 0 ; i < nr ; i++) { |
203 | if (bhs[i] == NULL) { | |
31d33073 | 204 | bhs[i] = sb_getblk(inode->i_sb, block++); |
ccd979bd | 205 | if (bhs[i] == NULL) { |
31d33073 | 206 | mutex_unlock(&OCFS2_I(inode)->ip_io_mutex); |
ccd979bd MF |
207 | status = -EIO; |
208 | mlog_errno(status); | |
209 | goto bail; | |
210 | } | |
211 | } | |
212 | bh = bhs[i]; | |
d4a8c93c | 213 | ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE); |
ccd979bd | 214 | |
aa958874 MF |
215 | /* There are three read-ahead cases here which we need to |
216 | * be concerned with. All three assume a buffer has | |
217 | * previously been submitted with OCFS2_BH_READAHEAD | |
218 | * and it hasn't yet completed I/O. | |
219 | * | |
220 | * 1) The current request is sync to disk. This rarely | |
221 | * happens these days, and never when performance | |
222 | * matters - the code can just wait on the buffer | |
223 | * lock and re-submit. | |
224 | * | |
225 | * 2) The current request is cached, but not | |
226 | * readahead. ocfs2_buffer_uptodate() will return | |
227 | * false anyway, so we'll wind up waiting on the | |
228 | * buffer lock to do I/O. We re-check the request | |
229 | * with after getting the lock to avoid a re-submit. | |
230 | * | |
231 | * 3) The current request is readahead (and so must | |
232 | * also be a caching one). We short circuit if the | |
233 | * buffer is locked (under I/O) and if it's in the | |
234 | * uptodate cache. The re-check from #2 catches the | |
235 | * case that the previous read-ahead completes just | |
236 | * before our is-it-in-flight check. | |
237 | */ | |
238 | ||
d4a8c93c | 239 | if (!ignore_cache && !ocfs2_buffer_uptodate(inode, bh)) { |
ccd979bd | 240 | mlog(ML_UPTODATE, |
b0697053 | 241 | "bh (%llu), inode %llu not uptodate\n", |
ccd979bd | 242 | (unsigned long long)bh->b_blocknr, |
b0697053 | 243 | (unsigned long long)OCFS2_I(inode)->ip_blkno); |
d4a8c93c JB |
244 | /* We're using ignore_cache here to say |
245 | * "go to disk" */ | |
ccd979bd MF |
246 | ignore_cache = 1; |
247 | } | |
248 | ||
ccd979bd | 249 | if (buffer_jbd(bh)) { |
d4a8c93c | 250 | if (ignore_cache) |
ccd979bd MF |
251 | mlog(ML_BH_IO, "trying to sync read a jbd " |
252 | "managed bh (blocknr = %llu)\n", | |
253 | (unsigned long long)bh->b_blocknr); | |
254 | continue; | |
255 | } | |
256 | ||
d4a8c93c | 257 | if (ignore_cache) { |
ccd979bd MF |
258 | if (buffer_dirty(bh)) { |
259 | /* This should probably be a BUG, or | |
260 | * at least return an error. */ | |
261 | mlog(ML_BH_IO, "asking me to sync read a dirty " | |
262 | "buffer! (blocknr = %llu)\n", | |
263 | (unsigned long long)bh->b_blocknr); | |
264 | continue; | |
265 | } | |
266 | ||
aa958874 MF |
267 | /* A read-ahead request was made - if the |
268 | * buffer is already under read-ahead from a | |
269 | * previously submitted request than we are | |
270 | * done here. */ | |
271 | if ((flags & OCFS2_BH_READAHEAD) | |
272 | && ocfs2_buffer_read_ahead(inode, bh)) | |
273 | continue; | |
274 | ||
ccd979bd MF |
275 | lock_buffer(bh); |
276 | if (buffer_jbd(bh)) { | |
277 | #ifdef CATCH_BH_JBD_RACES | |
278 | mlog(ML_ERROR, "block %llu had the JBD bit set " | |
279 | "while I was in lock_buffer!", | |
280 | (unsigned long long)bh->b_blocknr); | |
281 | BUG(); | |
282 | #else | |
283 | unlock_buffer(bh); | |
284 | continue; | |
285 | #endif | |
286 | } | |
aa958874 MF |
287 | |
288 | /* Re-check ocfs2_buffer_uptodate() as a | |
289 | * previously read-ahead buffer may have | |
290 | * completed I/O while we were waiting for the | |
291 | * buffer lock. */ | |
d4a8c93c | 292 | if (!(flags & OCFS2_BH_IGNORE_CACHE) |
aa958874 MF |
293 | && !(flags & OCFS2_BH_READAHEAD) |
294 | && ocfs2_buffer_uptodate(inode, bh)) { | |
295 | unlock_buffer(bh); | |
296 | continue; | |
297 | } | |
298 | ||
ccd979bd MF |
299 | clear_buffer_uptodate(bh); |
300 | get_bh(bh); /* for end_buffer_read_sync() */ | |
301 | bh->b_end_io = end_buffer_read_sync; | |
aa958874 | 302 | submit_bh(READ, bh); |
ccd979bd MF |
303 | continue; |
304 | } | |
305 | } | |
306 | ||
307 | status = 0; | |
308 | ||
309 | for (i = (nr - 1); i >= 0; i--) { | |
310 | bh = bhs[i]; | |
311 | ||
aa958874 MF |
312 | if (!(flags & OCFS2_BH_READAHEAD)) { |
313 | /* We know this can't have changed as we hold the | |
314 | * inode sem. Avoid doing any work on the bh if the | |
315 | * journal has it. */ | |
316 | if (!buffer_jbd(bh)) | |
317 | wait_on_buffer(bh); | |
318 | ||
319 | if (!buffer_uptodate(bh)) { | |
320 | /* Status won't be cleared from here on out, | |
321 | * so we can safely record this and loop back | |
322 | * to cleanup the other buffers. Don't need to | |
323 | * remove the clustered uptodate information | |
324 | * for this bh as it's not marked locally | |
325 | * uptodate. */ | |
326 | status = -EIO; | |
2fe5c1d7 | 327 | put_bh(bh); |
aa958874 MF |
328 | bhs[i] = NULL; |
329 | continue; | |
330 | } | |
ccd979bd MF |
331 | } |
332 | ||
aa958874 MF |
333 | /* Always set the buffer in the cache, even if it was |
334 | * a forced read, or read-ahead which hasn't yet | |
335 | * completed. */ | |
31d33073 | 336 | ocfs2_set_buffer_uptodate(inode, bh); |
ccd979bd | 337 | } |
31d33073 | 338 | mutex_unlock(&OCFS2_I(inode)->ip_io_mutex); |
ccd979bd | 339 | |
aa958874 | 340 | mlog(ML_BH_IO, "block=(%llu), nr=(%d), cached=%s, flags=0x%x\n", |
b0697053 | 341 | (unsigned long long)block, nr, |
d4a8c93c JB |
342 | ((flags & OCFS2_BH_IGNORE_CACHE) || ignore_cache) ? "no" : "yes", |
343 | flags); | |
ccd979bd MF |
344 | |
345 | bail: | |
346 | ||
347 | mlog_exit(status); | |
348 | return status; | |
349 | } | |
d659072f TM |
350 | |
351 | /* Check whether the blkno is the super block or one of the backups. */ | |
352 | static void ocfs2_check_super_or_backup(struct super_block *sb, | |
353 | sector_t blkno) | |
354 | { | |
355 | int i; | |
356 | u64 backup_blkno; | |
357 | ||
358 | if (blkno == OCFS2_SUPER_BLOCK_BLKNO) | |
359 | return; | |
360 | ||
361 | for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) { | |
362 | backup_blkno = ocfs2_backup_super_blkno(sb, i); | |
363 | if (backup_blkno == blkno) | |
364 | return; | |
365 | } | |
366 | ||
367 | BUG(); | |
368 | } | |
369 | ||
370 | /* | |
371 | * Write super block and backups doesn't need to collaborate with journal, | |
372 | * so we don't need to lock ip_io_mutex and inode doesn't need to bea passed | |
373 | * into this function. | |
374 | */ | |
375 | int ocfs2_write_super_or_backup(struct ocfs2_super *osb, | |
376 | struct buffer_head *bh) | |
377 | { | |
378 | int ret = 0; | |
379 | ||
380 | mlog_entry_void(); | |
381 | ||
382 | BUG_ON(buffer_jbd(bh)); | |
383 | ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr); | |
384 | ||
385 | if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) { | |
386 | ret = -EROFS; | |
387 | goto out; | |
388 | } | |
389 | ||
390 | lock_buffer(bh); | |
391 | set_buffer_uptodate(bh); | |
392 | ||
393 | /* remove from dirty list before I/O. */ | |
394 | clear_buffer_dirty(bh); | |
395 | ||
396 | get_bh(bh); /* for end_buffer_write_sync() */ | |
397 | bh->b_end_io = end_buffer_write_sync; | |
398 | submit_bh(WRITE, bh); | |
399 | ||
400 | wait_on_buffer(bh); | |
401 | ||
402 | if (!buffer_uptodate(bh)) { | |
403 | ret = -EIO; | |
2fe5c1d7 | 404 | put_bh(bh); |
d659072f TM |
405 | } |
406 | ||
407 | out: | |
408 | mlog_exit(ret); | |
409 | return ret; | |
410 | } |