diff options
author | Mark Fasheh <mark.fasheh@oracle.com> | 2005-12-15 17:31:24 -0500 |
---|---|---|
committer | Joel Becker <joel.becker@oracle.com> | 2006-01-03 14:45:47 -0500 |
commit | ccd979bdbce9fba8412beb3f1de68a9d0171b12c (patch) | |
tree | c50ed941849ce06ccadd4ce27599b3ef9fdbe2ae /fs/ocfs2/aops.c | |
parent | 8df08c89c668e1bd922a053fdb5ba1fadbecbb38 (diff) |
[PATCH] OCFS2: The Second Oracle Cluster Filesystem
The OCFS2 file system module.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Diffstat (limited to 'fs/ocfs2/aops.c')
-rw-r--r-- | fs/ocfs2/aops.c | 643 |
1 files changed, 643 insertions, 0 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c new file mode 100644 index 00000000000..8f4467a930a --- /dev/null +++ b/fs/ocfs2/aops.c | |||
@@ -0,0 +1,643 @@ | |||
1 | /* -*- mode: c; c-basic-offset: 8; -*- | ||
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | ||
3 | * | ||
4 | * Copyright (C) 2002, 2004 Oracle. All rights reserved. | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or | ||
7 | * modify it under the terms of the GNU General Public | ||
8 | * License as published by the Free Software Foundation; either | ||
9 | * version 2 of the License, or (at your option) any later version. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
14 | * General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public | ||
17 | * License along with this program; if not, write to the | ||
18 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | ||
19 | * Boston, MA 021110-1307, USA. | ||
20 | */ | ||
21 | |||
22 | #include <linux/fs.h> | ||
23 | #include <linux/slab.h> | ||
24 | #include <linux/highmem.h> | ||
25 | #include <linux/pagemap.h> | ||
26 | #include <asm/byteorder.h> | ||
27 | |||
28 | #define MLOG_MASK_PREFIX ML_FILE_IO | ||
29 | #include <cluster/masklog.h> | ||
30 | |||
31 | #include "ocfs2.h" | ||
32 | |||
33 | #include "alloc.h" | ||
34 | #include "aops.h" | ||
35 | #include "dlmglue.h" | ||
36 | #include "extent_map.h" | ||
37 | #include "file.h" | ||
38 | #include "inode.h" | ||
39 | #include "journal.h" | ||
40 | #include "super.h" | ||
41 | #include "symlink.h" | ||
42 | |||
43 | #include "buffer_head_io.h" | ||
44 | |||
45 | static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock, | ||
46 | struct buffer_head *bh_result, int create) | ||
47 | { | ||
48 | int err = -EIO; | ||
49 | int status; | ||
50 | struct ocfs2_dinode *fe = NULL; | ||
51 | struct buffer_head *bh = NULL; | ||
52 | struct buffer_head *buffer_cache_bh = NULL; | ||
53 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); | ||
54 | void *kaddr; | ||
55 | |||
56 | mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, | ||
57 | (unsigned long long)iblock, bh_result, create); | ||
58 | |||
59 | BUG_ON(ocfs2_inode_is_fast_symlink(inode)); | ||
60 | |||
61 | if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) { | ||
62 | mlog(ML_ERROR, "block offset > PATH_MAX: %llu", | ||
63 | (unsigned long long)iblock); | ||
64 | goto bail; | ||
65 | } | ||
66 | |||
67 | status = ocfs2_read_block(OCFS2_SB(inode->i_sb), | ||
68 | OCFS2_I(inode)->ip_blkno, | ||
69 | &bh, OCFS2_BH_CACHED, inode); | ||
70 | if (status < 0) { | ||
71 | mlog_errno(status); | ||
72 | goto bail; | ||
73 | } | ||
74 | fe = (struct ocfs2_dinode *) bh->b_data; | ||
75 | |||
76 | if (!OCFS2_IS_VALID_DINODE(fe)) { | ||
77 | mlog(ML_ERROR, "Invalid dinode #%"MLFu64": signature = %.*s\n", | ||
78 | fe->i_blkno, 7, fe->i_signature); | ||
79 | goto bail; | ||
80 | } | ||
81 | |||
82 | if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb, | ||
83 | le32_to_cpu(fe->i_clusters))) { | ||
84 | mlog(ML_ERROR, "block offset is outside the allocated size: " | ||
85 | "%llu\n", (unsigned long long)iblock); | ||
86 | goto bail; | ||
87 | } | ||
88 | |||
89 | /* We don't use the page cache to create symlink data, so if | ||
90 | * need be, copy it over from the buffer cache. */ | ||
91 | if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) { | ||
92 | u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + | ||
93 | iblock; | ||
94 | buffer_cache_bh = sb_getblk(osb->sb, blkno); | ||
95 | if (!buffer_cache_bh) { | ||
96 | mlog(ML_ERROR, "couldn't getblock for symlink!\n"); | ||
97 | goto bail; | ||
98 | } | ||
99 | |||
100 | /* we haven't locked out transactions, so a commit | ||
101 | * could've happened. Since we've got a reference on | ||
102 | * the bh, even if it commits while we're doing the | ||
103 | * copy, the data is still good. */ | ||
104 | if (buffer_jbd(buffer_cache_bh) | ||
105 | && ocfs2_inode_is_new(inode)) { | ||
106 | kaddr = kmap_atomic(bh_result->b_page, KM_USER0); | ||
107 | if (!kaddr) { | ||
108 | mlog(ML_ERROR, "couldn't kmap!\n"); | ||
109 | goto bail; | ||
110 | } | ||
111 | memcpy(kaddr + (bh_result->b_size * iblock), | ||
112 | buffer_cache_bh->b_data, | ||
113 | bh_result->b_size); | ||
114 | kunmap_atomic(kaddr, KM_USER0); | ||
115 | set_buffer_uptodate(bh_result); | ||
116 | } | ||
117 | brelse(buffer_cache_bh); | ||
118 | } | ||
119 | |||
120 | map_bh(bh_result, inode->i_sb, | ||
121 | le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock); | ||
122 | |||
123 | err = 0; | ||
124 | |||
125 | bail: | ||
126 | if (bh) | ||
127 | brelse(bh); | ||
128 | |||
129 | mlog_exit(err); | ||
130 | return err; | ||
131 | } | ||
132 | |||
133 | static int ocfs2_get_block(struct inode *inode, sector_t iblock, | ||
134 | struct buffer_head *bh_result, int create) | ||
135 | { | ||
136 | int err = 0; | ||
137 | u64 p_blkno, past_eof; | ||
138 | |||
139 | mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, | ||
140 | (unsigned long long)iblock, bh_result, create); | ||
141 | |||
142 | if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) | ||
143 | mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n", | ||
144 | inode, inode->i_ino); | ||
145 | |||
146 | if (S_ISLNK(inode->i_mode)) { | ||
147 | /* this always does I/O for some reason. */ | ||
148 | err = ocfs2_symlink_get_block(inode, iblock, bh_result, create); | ||
149 | goto bail; | ||
150 | } | ||
151 | |||
152 | /* this can happen if another node truncs after our extend! */ | ||
153 | spin_lock(&OCFS2_I(inode)->ip_lock); | ||
154 | if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb, | ||
155 | OCFS2_I(inode)->ip_clusters)) | ||
156 | err = -EIO; | ||
157 | spin_unlock(&OCFS2_I(inode)->ip_lock); | ||
158 | if (err) | ||
159 | goto bail; | ||
160 | |||
161 | err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno, | ||
162 | NULL); | ||
163 | if (err) { | ||
164 | mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, " | ||
165 | "%"MLFu64", NULL)\n", err, inode, | ||
166 | (unsigned long long)iblock, p_blkno); | ||
167 | goto bail; | ||
168 | } | ||
169 | |||
170 | map_bh(bh_result, inode->i_sb, p_blkno); | ||
171 | |||
172 | if (bh_result->b_blocknr == 0) { | ||
173 | err = -EIO; | ||
174 | mlog(ML_ERROR, "iblock = %llu p_blkno = %"MLFu64" " | ||
175 | "blkno=(%"MLFu64")\n", (unsigned long long)iblock, | ||
176 | p_blkno, OCFS2_I(inode)->ip_blkno); | ||
177 | } | ||
178 | |||
179 | past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); | ||
180 | mlog(0, "Inode %lu, past_eof = %"MLFu64"\n", inode->i_ino, past_eof); | ||
181 | |||
182 | if (create && (iblock >= past_eof)) | ||
183 | set_buffer_new(bh_result); | ||
184 | |||
185 | bail: | ||
186 | if (err < 0) | ||
187 | err = -EIO; | ||
188 | |||
189 | mlog_exit(err); | ||
190 | return err; | ||
191 | } | ||
192 | |||
193 | static int ocfs2_readpage(struct file *file, struct page *page) | ||
194 | { | ||
195 | struct inode *inode = page->mapping->host; | ||
196 | loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT; | ||
197 | int ret, unlock = 1; | ||
198 | |||
199 | mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0)); | ||
200 | |||
201 | ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page); | ||
202 | if (ret != 0) { | ||
203 | if (ret == AOP_TRUNCATED_PAGE) | ||
204 | unlock = 0; | ||
205 | mlog_errno(ret); | ||
206 | goto out; | ||
207 | } | ||
208 | |||
209 | down_read(&OCFS2_I(inode)->ip_alloc_sem); | ||
210 | |||
211 | /* | ||
212 | * i_size might have just been updated as we grabed the meta lock. We | ||
213 | * might now be discovering a truncate that hit on another node. | ||
214 | * block_read_full_page->get_block freaks out if it is asked to read | ||
215 | * beyond the end of a file, so we check here. Callers | ||
216 | * (generic_file_read, fault->nopage) are clever enough to check i_size | ||
217 | * and notice that the page they just read isn't needed. | ||
218 | * | ||
219 | * XXX sys_readahead() seems to get that wrong? | ||
220 | */ | ||
221 | if (start >= i_size_read(inode)) { | ||
222 | char *addr = kmap(page); | ||
223 | memset(addr, 0, PAGE_SIZE); | ||
224 | flush_dcache_page(page); | ||
225 | kunmap(page); | ||
226 | SetPageUptodate(page); | ||
227 | ret = 0; | ||
228 | goto out_alloc; | ||
229 | } | ||
230 | |||
231 | ret = ocfs2_data_lock_with_page(inode, 0, page); | ||
232 | if (ret != 0) { | ||
233 | if (ret == AOP_TRUNCATED_PAGE) | ||
234 | unlock = 0; | ||
235 | mlog_errno(ret); | ||
236 | goto out_alloc; | ||
237 | } | ||
238 | |||
239 | ret = block_read_full_page(page, ocfs2_get_block); | ||
240 | unlock = 0; | ||
241 | |||
242 | ocfs2_data_unlock(inode, 0); | ||
243 | out_alloc: | ||
244 | up_read(&OCFS2_I(inode)->ip_alloc_sem); | ||
245 | ocfs2_meta_unlock(inode, 0); | ||
246 | out: | ||
247 | if (unlock) | ||
248 | unlock_page(page); | ||
249 | mlog_exit(ret); | ||
250 | return ret; | ||
251 | } | ||
252 | |||
253 | /* Note: Because we don't support holes, our allocation has | ||
254 | * already happened (allocation writes zeros to the file data) | ||
255 | * so we don't have to worry about ordered writes in | ||
256 | * ocfs2_writepage. | ||
257 | * | ||
258 | * ->writepage is called during the process of invalidating the page cache | ||
259 | * during blocked lock processing. It can't block on any cluster locks | ||
260 | * to during block mapping. It's relying on the fact that the block | ||
261 | * mapping can't have disappeared under the dirty pages that it is | ||
262 | * being asked to write back. | ||
263 | */ | ||
264 | static int ocfs2_writepage(struct page *page, struct writeback_control *wbc) | ||
265 | { | ||
266 | int ret; | ||
267 | |||
268 | mlog_entry("(0x%p)\n", page); | ||
269 | |||
270 | ret = block_write_full_page(page, ocfs2_get_block, wbc); | ||
271 | |||
272 | mlog_exit(ret); | ||
273 | |||
274 | return ret; | ||
275 | } | ||
276 | |||
277 | /* | ||
278 | * ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called | ||
279 | * from loopback. It must be able to perform its own locking around | ||
280 | * ocfs2_get_block(). | ||
281 | */ | ||
282 | int ocfs2_prepare_write(struct file *file, struct page *page, | ||
283 | unsigned from, unsigned to) | ||
284 | { | ||
285 | struct inode *inode = page->mapping->host; | ||
286 | int ret; | ||
287 | |||
288 | mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to); | ||
289 | |||
290 | ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page); | ||
291 | if (ret != 0) { | ||
292 | mlog_errno(ret); | ||
293 | goto out; | ||
294 | } | ||
295 | |||
296 | down_read(&OCFS2_I(inode)->ip_alloc_sem); | ||
297 | |||
298 | ret = block_prepare_write(page, from, to, ocfs2_get_block); | ||
299 | |||
300 | up_read(&OCFS2_I(inode)->ip_alloc_sem); | ||
301 | |||
302 | ocfs2_meta_unlock(inode, 0); | ||
303 | out: | ||
304 | mlog_exit(ret); | ||
305 | return ret; | ||
306 | } | ||
307 | |||
308 | /* Taken from ext3. We don't necessarily need the full blown | ||
309 | * functionality yet, but IMHO it's better to cut and paste the whole | ||
310 | * thing so we can avoid introducing our own bugs (and easily pick up | ||
311 | * their fixes when they happen) --Mark */ | ||
312 | static int walk_page_buffers( handle_t *handle, | ||
313 | struct buffer_head *head, | ||
314 | unsigned from, | ||
315 | unsigned to, | ||
316 | int *partial, | ||
317 | int (*fn)( handle_t *handle, | ||
318 | struct buffer_head *bh)) | ||
319 | { | ||
320 | struct buffer_head *bh; | ||
321 | unsigned block_start, block_end; | ||
322 | unsigned blocksize = head->b_size; | ||
323 | int err, ret = 0; | ||
324 | struct buffer_head *next; | ||
325 | |||
326 | for ( bh = head, block_start = 0; | ||
327 | ret == 0 && (bh != head || !block_start); | ||
328 | block_start = block_end, bh = next) | ||
329 | { | ||
330 | next = bh->b_this_page; | ||
331 | block_end = block_start + blocksize; | ||
332 | if (block_end <= from || block_start >= to) { | ||
333 | if (partial && !buffer_uptodate(bh)) | ||
334 | *partial = 1; | ||
335 | continue; | ||
336 | } | ||
337 | err = (*fn)(handle, bh); | ||
338 | if (!ret) | ||
339 | ret = err; | ||
340 | } | ||
341 | return ret; | ||
342 | } | ||
343 | |||
344 | struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode, | ||
345 | struct page *page, | ||
346 | unsigned from, | ||
347 | unsigned to) | ||
348 | { | ||
349 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); | ||
350 | struct ocfs2_journal_handle *handle = NULL; | ||
351 | int ret = 0; | ||
352 | |||
353 | handle = ocfs2_start_trans(osb, NULL, OCFS2_INODE_UPDATE_CREDITS); | ||
354 | if (!handle) { | ||
355 | ret = -ENOMEM; | ||
356 | mlog_errno(ret); | ||
357 | goto out; | ||
358 | } | ||
359 | |||
360 | if (ocfs2_should_order_data(inode)) { | ||
361 | ret = walk_page_buffers(handle->k_handle, | ||
362 | page_buffers(page), | ||
363 | from, to, NULL, | ||
364 | ocfs2_journal_dirty_data); | ||
365 | if (ret < 0) | ||
366 | mlog_errno(ret); | ||
367 | } | ||
368 | out: | ||
369 | if (ret) { | ||
370 | if (handle) | ||
371 | ocfs2_commit_trans(handle); | ||
372 | handle = ERR_PTR(ret); | ||
373 | } | ||
374 | return handle; | ||
375 | } | ||
376 | |||
377 | static int ocfs2_commit_write(struct file *file, struct page *page, | ||
378 | unsigned from, unsigned to) | ||
379 | { | ||
380 | int ret, extending = 0, locklevel = 0; | ||
381 | loff_t new_i_size; | ||
382 | struct buffer_head *di_bh = NULL; | ||
383 | struct inode *inode = page->mapping->host; | ||
384 | struct ocfs2_journal_handle *handle = NULL; | ||
385 | |||
386 | mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to); | ||
387 | |||
388 | /* NOTE: ocfs2_file_aio_write has ensured that it's safe for | ||
389 | * us to sample inode->i_size here without the metadata lock: | ||
390 | * | ||
391 | * 1) We're currently holding the inode alloc lock, so no | ||
392 | * nodes can change it underneath us. | ||
393 | * | ||
394 | * 2) We've had to take the metadata lock at least once | ||
395 | * already to check for extending writes, hence insuring | ||
396 | * that our current copy is also up to date. | ||
397 | */ | ||
398 | new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | ||
399 | if (new_i_size > i_size_read(inode)) { | ||
400 | extending = 1; | ||
401 | locklevel = 1; | ||
402 | } | ||
403 | |||
404 | ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, locklevel, page); | ||
405 | if (ret != 0) { | ||
406 | mlog_errno(ret); | ||
407 | goto out; | ||
408 | } | ||
409 | |||
410 | ret = ocfs2_data_lock_with_page(inode, 1, page); | ||
411 | if (ret != 0) { | ||
412 | mlog_errno(ret); | ||
413 | goto out_unlock_meta; | ||
414 | } | ||
415 | |||
416 | if (extending) { | ||
417 | handle = ocfs2_start_walk_page_trans(inode, page, from, to); | ||
418 | if (IS_ERR(handle)) { | ||
419 | ret = PTR_ERR(handle); | ||
420 | handle = NULL; | ||
421 | goto out_unlock_data; | ||
422 | } | ||
423 | |||
424 | /* Mark our buffer early. We'd rather catch this error up here | ||
425 | * as opposed to after a successful commit_write which would | ||
426 | * require us to set back inode->i_size. */ | ||
427 | ret = ocfs2_journal_access(handle, inode, di_bh, | ||
428 | OCFS2_JOURNAL_ACCESS_WRITE); | ||
429 | if (ret < 0) { | ||
430 | mlog_errno(ret); | ||
431 | goto out_commit; | ||
432 | } | ||
433 | } | ||
434 | |||
435 | /* might update i_size */ | ||
436 | ret = generic_commit_write(file, page, from, to); | ||
437 | if (ret < 0) { | ||
438 | mlog_errno(ret); | ||
439 | goto out_commit; | ||
440 | } | ||
441 | |||
442 | if (extending) { | ||
443 | loff_t size = (u64) i_size_read(inode); | ||
444 | struct ocfs2_dinode *di = | ||
445 | (struct ocfs2_dinode *)di_bh->b_data; | ||
446 | |||
447 | /* ocfs2_mark_inode_dirty is too heavy to use here. */ | ||
448 | inode->i_blocks = ocfs2_align_bytes_to_sectors(size); | ||
449 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; | ||
450 | |||
451 | di->i_size = cpu_to_le64(size); | ||
452 | di->i_ctime = di->i_mtime = | ||
453 | cpu_to_le64(inode->i_mtime.tv_sec); | ||
454 | di->i_ctime_nsec = di->i_mtime_nsec = | ||
455 | cpu_to_le32(inode->i_mtime.tv_nsec); | ||
456 | |||
457 | ret = ocfs2_journal_dirty(handle, di_bh); | ||
458 | if (ret < 0) { | ||
459 | mlog_errno(ret); | ||
460 | goto out_commit; | ||
461 | } | ||
462 | } | ||
463 | |||
464 | BUG_ON(extending && (i_size_read(inode) != new_i_size)); | ||
465 | |||
466 | out_commit: | ||
467 | if (handle) | ||
468 | ocfs2_commit_trans(handle); | ||
469 | out_unlock_data: | ||
470 | ocfs2_data_unlock(inode, 1); | ||
471 | out_unlock_meta: | ||
472 | ocfs2_meta_unlock(inode, locklevel); | ||
473 | out: | ||
474 | if (di_bh) | ||
475 | brelse(di_bh); | ||
476 | |||
477 | mlog_exit(ret); | ||
478 | return ret; | ||
479 | } | ||
480 | |||
481 | static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block) | ||
482 | { | ||
483 | sector_t status; | ||
484 | u64 p_blkno = 0; | ||
485 | int err = 0; | ||
486 | struct inode *inode = mapping->host; | ||
487 | |||
488 | mlog_entry("(block = %llu)\n", (unsigned long long)block); | ||
489 | |||
490 | /* We don't need to lock journal system files, since they aren't | ||
491 | * accessed concurrently from multiple nodes. | ||
492 | */ | ||
493 | if (!INODE_JOURNAL(inode)) { | ||
494 | err = ocfs2_meta_lock(inode, NULL, NULL, 0); | ||
495 | if (err) { | ||
496 | if (err != -ENOENT) | ||
497 | mlog_errno(err); | ||
498 | goto bail; | ||
499 | } | ||
500 | down_read(&OCFS2_I(inode)->ip_alloc_sem); | ||
501 | } | ||
502 | |||
503 | err = ocfs2_extent_map_get_blocks(inode, block, 1, &p_blkno, | ||
504 | NULL); | ||
505 | |||
506 | if (!INODE_JOURNAL(inode)) { | ||
507 | up_read(&OCFS2_I(inode)->ip_alloc_sem); | ||
508 | ocfs2_meta_unlock(inode, 0); | ||
509 | } | ||
510 | |||
511 | if (err) { | ||
512 | mlog(ML_ERROR, "get_blocks() failed, block = %llu\n", | ||
513 | (unsigned long long)block); | ||
514 | mlog_errno(err); | ||
515 | goto bail; | ||
516 | } | ||
517 | |||
518 | |||
519 | bail: | ||
520 | status = err ? 0 : p_blkno; | ||
521 | |||
522 | mlog_exit((int)status); | ||
523 | |||
524 | return status; | ||
525 | } | ||
526 | |||
527 | /* | ||
528 | * TODO: Make this into a generic get_blocks function. | ||
529 | * | ||
530 | * From do_direct_io in direct-io.c: | ||
531 | * "So what we do is to permit the ->get_blocks function to populate | ||
532 | * bh.b_size with the size of IO which is permitted at this offset and | ||
533 | * this i_blkbits." | ||
534 | * | ||
535 | * This function is called directly from get_more_blocks in direct-io.c. | ||
536 | * | ||
537 | * called like this: dio->get_blocks(dio->inode, fs_startblk, | ||
538 | * fs_count, map_bh, dio->rw == WRITE); | ||
539 | */ | ||
540 | static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, | ||
541 | unsigned long max_blocks, | ||
542 | struct buffer_head *bh_result, int create) | ||
543 | { | ||
544 | int ret; | ||
545 | u64 vbo_max; /* file offset, max_blocks from iblock */ | ||
546 | u64 p_blkno; | ||
547 | int contig_blocks; | ||
548 | unsigned char blocksize_bits; | ||
549 | |||
550 | if (!inode || !bh_result) { | ||
551 | mlog(ML_ERROR, "inode or bh_result is null\n"); | ||
552 | return -EIO; | ||
553 | } | ||
554 | |||
555 | blocksize_bits = inode->i_sb->s_blocksize_bits; | ||
556 | |||
557 | /* This function won't even be called if the request isn't all | ||
558 | * nicely aligned and of the right size, so there's no need | ||
559 | * for us to check any of that. */ | ||
560 | |||
561 | vbo_max = ((u64)iblock + max_blocks) << blocksize_bits; | ||
562 | |||
563 | spin_lock(&OCFS2_I(inode)->ip_lock); | ||
564 | if ((iblock + max_blocks) > | ||
565 | ocfs2_clusters_to_blocks(inode->i_sb, | ||
566 | OCFS2_I(inode)->ip_clusters)) { | ||
567 | spin_unlock(&OCFS2_I(inode)->ip_lock); | ||
568 | ret = -EIO; | ||
569 | goto bail; | ||
570 | } | ||
571 | spin_unlock(&OCFS2_I(inode)->ip_lock); | ||
572 | |||
573 | /* This figures out the size of the next contiguous block, and | ||
574 | * our logical offset */ | ||
575 | ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno, | ||
576 | &contig_blocks); | ||
577 | if (ret) { | ||
578 | mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n", | ||
579 | (unsigned long long)iblock); | ||
580 | ret = -EIO; | ||
581 | goto bail; | ||
582 | } | ||
583 | |||
584 | map_bh(bh_result, inode->i_sb, p_blkno); | ||
585 | |||
586 | /* make sure we don't map more than max_blocks blocks here as | ||
587 | that's all the kernel will handle at this point. */ | ||
588 | if (max_blocks < contig_blocks) | ||
589 | contig_blocks = max_blocks; | ||
590 | bh_result->b_size = contig_blocks << blocksize_bits; | ||
591 | bail: | ||
592 | return ret; | ||
593 | } | ||
594 | |||
595 | /* | ||
596 | * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're | ||
597 | * particularly interested in the aio/dio case. Like the core uses | ||
598 | * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from | ||
599 | * truncation on another. | ||
600 | */ | ||
601 | static void ocfs2_dio_end_io(struct kiocb *iocb, | ||
602 | loff_t offset, | ||
603 | ssize_t bytes, | ||
604 | void *private) | ||
605 | { | ||
606 | struct inode *inode = iocb->ki_filp->f_dentry->d_inode; | ||
607 | |||
608 | /* this io's submitter should not have unlocked this before we could */ | ||
609 | BUG_ON(!ocfs2_iocb_is_rw_locked(iocb)); | ||
610 | ocfs2_iocb_clear_rw_locked(iocb); | ||
611 | up_read(&inode->i_alloc_sem); | ||
612 | ocfs2_rw_unlock(inode, 0); | ||
613 | } | ||
614 | |||
615 | static ssize_t ocfs2_direct_IO(int rw, | ||
616 | struct kiocb *iocb, | ||
617 | const struct iovec *iov, | ||
618 | loff_t offset, | ||
619 | unsigned long nr_segs) | ||
620 | { | ||
621 | struct file *file = iocb->ki_filp; | ||
622 | struct inode *inode = file->f_dentry->d_inode->i_mapping->host; | ||
623 | int ret; | ||
624 | |||
625 | mlog_entry_void(); | ||
626 | ret = blockdev_direct_IO_no_locking(rw, iocb, inode, | ||
627 | inode->i_sb->s_bdev, iov, offset, | ||
628 | nr_segs, | ||
629 | ocfs2_direct_IO_get_blocks, | ||
630 | ocfs2_dio_end_io); | ||
631 | mlog_exit(ret); | ||
632 | return ret; | ||
633 | } | ||
634 | |||
635 | struct address_space_operations ocfs2_aops = { | ||
636 | .readpage = ocfs2_readpage, | ||
637 | .writepage = ocfs2_writepage, | ||
638 | .prepare_write = ocfs2_prepare_write, | ||
639 | .commit_write = ocfs2_commit_write, | ||
640 | .bmap = ocfs2_bmap, | ||
641 | .sync_page = block_sync_page, | ||
642 | .direct_IO = ocfs2_direct_IO | ||
643 | }; | ||