]>
Commit | Line | Data |
---|---|---|
b3b94faa DT |
1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
3 | * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This copyrighted material is made available to anyone wishing to use, | |
6 | * modify, copy, or redistribute it subject to the terms and conditions | |
7 | * of the GNU General Public License v.2. | |
8 | */ | |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/buffer_head.h> | |
15 | #include <linux/pagemap.h> | |
fd88de56 | 16 | #include <linux/pagevec.h> |
9b124fbb | 17 | #include <linux/mpage.h> |
d1665e41 | 18 | #include <linux/fs.h> |
5c676f6d | 19 | #include <linux/gfs2_ondisk.h> |
b3b94faa DT |
20 | |
21 | #include "gfs2.h" | |
5c676f6d SW |
22 | #include "lm_interface.h" |
23 | #include "incore.h" | |
b3b94faa DT |
24 | #include "bmap.h" |
25 | #include "glock.h" | |
26 | #include "inode.h" | |
b3b94faa DT |
27 | #include "log.h" |
28 | #include "meta_io.h" | |
29 | #include "ops_address.h" | |
30 | #include "page.h" | |
31 | #include "quota.h" | |
32 | #include "trans.h" | |
18ec7d5c | 33 | #include "rgrp.h" |
61a30dcb | 34 | #include "ops_file.h" |
5c676f6d | 35 | #include "util.h" |
b3b94faa DT |
36 | |
37 | /** | |
4ff14670 | 38 | * gfs2_get_block - Fills in a buffer head with details about a block |
b3b94faa DT |
39 | * @inode: The inode |
40 | * @lblock: The block number to look up | |
41 | * @bh_result: The buffer head to return the result in | |
42 | * @create: Non-zero if we may add block to the file | |
43 | * | |
44 | * Returns: errno | |
45 | */ | |
46 | ||
4ff14670 SW |
47 | int gfs2_get_block(struct inode *inode, sector_t lblock, |
48 | struct buffer_head *bh_result, int create) | |
b3b94faa | 49 | { |
b3b94faa DT |
50 | int new = create; |
51 | uint64_t dblock; | |
52 | int error; | |
fd88de56 | 53 | int boundary; |
b3b94faa | 54 | |
fd88de56 | 55 | error = gfs2_block_map(inode, lblock, &new, &dblock, &boundary); |
b3b94faa DT |
56 | if (error) |
57 | return error; | |
58 | ||
59 | if (!dblock) | |
60 | return 0; | |
61 | ||
62 | map_bh(bh_result, inode->i_sb, dblock); | |
63 | if (new) | |
64 | set_buffer_new(bh_result); | |
fd88de56 SW |
65 | if (boundary) |
66 | set_buffer_boundary(bh_result); | |
b3b94faa DT |
67 | |
68 | return 0; | |
69 | } | |
70 | ||
71 | /** | |
72 | * get_block_noalloc - Fills in a buffer head with details about a block | |
73 | * @inode: The inode | |
74 | * @lblock: The block number to look up | |
75 | * @bh_result: The buffer head to return the result in | |
76 | * @create: Non-zero if we may add block to the file | |
77 | * | |
78 | * Returns: errno | |
79 | */ | |
80 | ||
81 | static int get_block_noalloc(struct inode *inode, sector_t lblock, | |
82 | struct buffer_head *bh_result, int create) | |
83 | { | |
5c676f6d | 84 | struct gfs2_inode *ip = inode->u.generic_ip; |
b3b94faa DT |
85 | int new = 0; |
86 | uint64_t dblock; | |
87 | int error; | |
fd88de56 | 88 | int boundary; |
b3b94faa | 89 | |
fd88de56 | 90 | error = gfs2_block_map(inode, lblock, &new, &dblock, &boundary); |
b3b94faa DT |
91 | if (error) |
92 | return error; | |
93 | ||
94 | if (dblock) | |
95 | map_bh(bh_result, inode->i_sb, dblock); | |
96 | else if (gfs2_assert_withdraw(ip->i_sbd, !create)) | |
97 | error = -EIO; | |
fd88de56 SW |
98 | if (boundary) |
99 | set_buffer_boundary(bh_result); | |
b3b94faa DT |
100 | |
101 | return error; | |
102 | } | |
103 | ||
b3b94faa DT |
104 | /** |
105 | * gfs2_writepage - Write complete page | |
106 | * @page: Page to write | |
107 | * | |
108 | * Returns: errno | |
109 | * | |
18ec7d5c SW |
110 | * Some of this is copied from block_write_full_page() although we still |
111 | * call it to do most of the work. | |
b3b94faa DT |
112 | */ |
113 | ||
114 | static int gfs2_writepage(struct page *page, struct writeback_control *wbc) | |
115 | { | |
18ec7d5c | 116 | struct inode *inode = page->mapping->host; |
5c676f6d | 117 | struct gfs2_inode *ip = page->mapping->host->u.generic_ip; |
b3b94faa | 118 | struct gfs2_sbd *sdp = ip->i_sbd; |
18ec7d5c SW |
119 | loff_t i_size = i_size_read(inode); |
120 | pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; | |
121 | unsigned offset; | |
b3b94faa | 122 | int error; |
18ec7d5c | 123 | int done_trans = 0; |
b3b94faa | 124 | |
b3b94faa DT |
125 | if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) { |
126 | unlock_page(page); | |
127 | return -EIO; | |
128 | } | |
5c676f6d | 129 | if (current->journal_info) |
18ec7d5c SW |
130 | goto out_ignore; |
131 | ||
132 | /* Is the page fully outside i_size? (truncate in progress) */ | |
133 | offset = i_size & (PAGE_CACHE_SIZE-1); | |
d2d7b8a2 | 134 | if (page->index > end_index || (page->index == end_index && !offset)) { |
18ec7d5c | 135 | page->mapping->a_ops->invalidatepage(page, 0); |
b3b94faa | 136 | unlock_page(page); |
18ec7d5c | 137 | return 0; /* don't care */ |
b3b94faa DT |
138 | } |
139 | ||
18ec7d5c SW |
140 | if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) { |
141 | error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); | |
142 | if (error) | |
143 | goto out_ignore; | |
144 | gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1); | |
145 | done_trans = 1; | |
146 | } | |
18ec7d5c SW |
147 | error = block_write_full_page(page, get_block_noalloc, wbc); |
148 | if (done_trans) | |
149 | gfs2_trans_end(sdp); | |
b3b94faa | 150 | gfs2_meta_cache_flush(ip); |
b3b94faa | 151 | return error; |
18ec7d5c SW |
152 | |
153 | out_ignore: | |
154 | redirty_page_for_writepage(wbc, page); | |
155 | unlock_page(page); | |
156 | return 0; | |
b3b94faa DT |
157 | } |
158 | ||
fd88de56 SW |
159 | static int zero_readpage(struct page *page) |
160 | { | |
161 | void *kaddr; | |
162 | ||
163 | kaddr = kmap_atomic(page, KM_USER0); | |
164 | memset(kaddr, 0, PAGE_CACHE_SIZE); | |
165 | kunmap_atomic(page, KM_USER0); | |
166 | ||
167 | SetPageUptodate(page); | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
b3b94faa DT |
172 | /** |
173 | * stuffed_readpage - Fill in a Linux page with stuffed file data | |
174 | * @ip: the inode | |
175 | * @page: the page | |
176 | * | |
177 | * Returns: errno | |
178 | */ | |
179 | ||
180 | static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) | |
181 | { | |
182 | struct buffer_head *dibh; | |
183 | void *kaddr; | |
184 | int error; | |
185 | ||
fd88de56 SW |
186 | /* Only the first page of a stuffed file might contain data */ |
187 | if (unlikely(page->index)) | |
188 | return zero_readpage(page); | |
189 | ||
b3b94faa DT |
190 | error = gfs2_meta_inode_buffer(ip, &dibh); |
191 | if (error) | |
192 | return error; | |
193 | ||
5c4e9e03 | 194 | kaddr = kmap_atomic(page, KM_USER0); |
fd88de56 | 195 | memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), |
b3b94faa | 196 | ip->i_di.di_size); |
fd88de56 | 197 | memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size); |
5c4e9e03 | 198 | kunmap_atomic(page, KM_USER0); |
b3b94faa DT |
199 | |
200 | brelse(dibh); | |
201 | ||
202 | SetPageUptodate(page); | |
203 | ||
204 | return 0; | |
205 | } | |
206 | ||
b3b94faa | 207 | |
b3b94faa DT |
208 | /** |
209 | * gfs2_readpage - readpage with locking | |
18ec7d5c SW |
210 | * @file: The file to read a page for. N.B. This may be NULL if we are |
211 | * reading an internal file. | |
b3b94faa DT |
212 | * @page: The page to read |
213 | * | |
214 | * Returns: errno | |
215 | */ | |
216 | ||
217 | static int gfs2_readpage(struct file *file, struct page *page) | |
218 | { | |
5c676f6d | 219 | struct gfs2_inode *ip = page->mapping->host->u.generic_ip; |
b3b94faa | 220 | struct gfs2_sbd *sdp = ip->i_sbd; |
18ec7d5c | 221 | struct gfs2_holder gh; |
b3b94faa DT |
222 | int error; |
223 | ||
fd88de56 | 224 | if (likely(file != &gfs2_internal_file_sentinal)) { |
fe1bdedc | 225 | gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh); |
61a30dcb | 226 | error = gfs2_glock_nq_m_atime(1, &gh); |
fd88de56 | 227 | if (unlikely(error)) |
61a30dcb SW |
228 | goto out_unlock; |
229 | } | |
b3b94faa | 230 | |
18ec7d5c | 231 | if (gfs2_is_stuffed(ip)) { |
fd88de56 SW |
232 | error = stuffed_readpage(ip, page); |
233 | unlock_page(page); | |
b3b94faa | 234 | } else |
18ec7d5c | 235 | error = mpage_readpage(page, gfs2_get_block); |
b3b94faa DT |
236 | |
237 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) | |
238 | error = -EIO; | |
239 | ||
61a30dcb SW |
240 | if (file != &gfs2_internal_file_sentinal) { |
241 | gfs2_glock_dq_m(1, &gh); | |
242 | gfs2_holder_uninit(&gh); | |
243 | } | |
18ec7d5c | 244 | out: |
b3b94faa | 245 | return error; |
18ec7d5c SW |
246 | out_unlock: |
247 | unlock_page(page); | |
fd88de56 SW |
248 | if (file != &gfs2_internal_file_sentinal) |
249 | gfs2_holder_uninit(&gh); | |
250 | goto out; | |
251 | } | |
252 | ||
253 | #define list_to_page(head) (list_entry((head)->prev, struct page, lru)) | |
254 | ||
255 | /** | |
256 | * gfs2_readpages - Read a bunch of pages at once | |
257 | * | |
258 | * Some notes: | |
259 | * 1. This is only for readahead, so we can simply ignore any things | |
260 | * which are slightly inconvenient (such as locking conflicts between | |
261 | * the page lock and the glock) and return having done no I/O. Its | |
262 | * obviously not something we'd want to do on too regular a basis. | |
263 | * Any I/O we ignore at this time will be done via readpage later. | |
264 | * 2. We have to handle stuffed files here too. | |
265 | * 3. mpage_readpages() does most of the heavy lifting in the common case. | |
266 | * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places. | |
267 | * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as | |
268 | * well as read-ahead. | |
269 | */ | |
270 | static int gfs2_readpages(struct file *file, struct address_space *mapping, | |
271 | struct list_head *pages, unsigned nr_pages) | |
272 | { | |
273 | struct inode *inode = mapping->host; | |
274 | struct gfs2_inode *ip = inode->u.generic_ip; | |
275 | struct gfs2_sbd *sdp = ip->i_sbd; | |
276 | struct gfs2_holder gh; | |
277 | unsigned page_idx; | |
278 | int ret; | |
279 | ||
280 | if (likely(file != &gfs2_internal_file_sentinal)) { | |
281 | gfs2_holder_init(ip->i_gl, LM_ST_SHARED, | |
282 | LM_FLAG_TRY_1CB|GL_ATIME|GL_AOP, &gh); | |
283 | ret = gfs2_glock_nq_m_atime(1, &gh); | |
284 | if (ret == GLR_TRYFAILED) | |
285 | goto out_noerror; | |
286 | if (unlikely(ret)) | |
287 | goto out_unlock; | |
288 | } | |
289 | ||
290 | if (gfs2_is_stuffed(ip)) { | |
291 | struct pagevec lru_pvec; | |
292 | pagevec_init(&lru_pvec, 0); | |
293 | for (page_idx = 0; page_idx < nr_pages; page_idx++) { | |
294 | struct page *page = list_to_page(pages); | |
295 | list_del(&page->lru); | |
296 | if (!add_to_page_cache(page, mapping, | |
297 | page->index, GFP_KERNEL)) { | |
298 | ret = stuffed_readpage(ip, page); | |
299 | unlock_page(page); | |
300 | if (!pagevec_add(&lru_pvec, page)) | |
301 | __pagevec_lru_add(&lru_pvec); | |
302 | } | |
303 | page_cache_release(page); | |
304 | } | |
305 | pagevec_lru_add(&lru_pvec); | |
306 | ret = 0; | |
307 | } else { | |
308 | /* What we really want to do .... */ | |
309 | ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block); | |
310 | } | |
311 | ||
312 | if (likely(file != &gfs2_internal_file_sentinal)) { | |
313 | gfs2_glock_dq_m(1, &gh); | |
314 | gfs2_holder_uninit(&gh); | |
315 | } | |
316 | out: | |
317 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) | |
318 | ret = -EIO; | |
319 | return ret; | |
320 | out_noerror: | |
321 | ret = 0; | |
322 | out_unlock: | |
323 | /* unlock all pages, we can't do any I/O right now */ | |
324 | for (page_idx = 0; page_idx < nr_pages; page_idx++) { | |
325 | struct page *page = list_to_page(pages); | |
326 | list_del(&page->lru); | |
327 | unlock_page(page); | |
328 | page_cache_release(page); | |
329 | } | |
330 | if (likely(file != &gfs2_internal_file_sentinal)) | |
331 | gfs2_holder_uninit(&gh); | |
18ec7d5c | 332 | goto out; |
b3b94faa DT |
333 | } |
334 | ||
335 | /** | |
336 | * gfs2_prepare_write - Prepare to write a page to a file | |
337 | * @file: The file to write to | |
338 | * @page: The page which is to be prepared for writing | |
339 | * @from: From (byte range within page) | |
340 | * @to: To (byte range within page) | |
341 | * | |
342 | * Returns: errno | |
343 | */ | |
344 | ||
345 | static int gfs2_prepare_write(struct file *file, struct page *page, | |
346 | unsigned from, unsigned to) | |
347 | { | |
5c676f6d | 348 | struct gfs2_inode *ip = page->mapping->host->u.generic_ip; |
b3b94faa | 349 | struct gfs2_sbd *sdp = ip->i_sbd; |
18ec7d5c SW |
350 | unsigned int data_blocks, ind_blocks, rblocks; |
351 | int alloc_required; | |
b3b94faa | 352 | int error = 0; |
18ec7d5c SW |
353 | loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from; |
354 | loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | |
355 | struct gfs2_alloc *al; | |
b3b94faa | 356 | |
fe1bdedc | 357 | gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh); |
18ec7d5c SW |
358 | error = gfs2_glock_nq_m_atime(1, &ip->i_gh); |
359 | if (error) | |
360 | goto out_uninit; | |
b3b94faa | 361 | |
18ec7d5c SW |
362 | gfs2_write_calc_reserv(ip, to - from, &data_blocks, &ind_blocks); |
363 | ||
364 | error = gfs2_write_alloc_required(ip, pos, from - to, &alloc_required); | |
365 | if (error) | |
366 | goto out_unlock; | |
b3b94faa | 367 | |
18ec7d5c SW |
368 | |
369 | if (alloc_required) { | |
370 | al = gfs2_alloc_get(ip); | |
371 | ||
372 | error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); | |
373 | if (error) | |
374 | goto out_alloc_put; | |
375 | ||
376 | error = gfs2_quota_check(ip, ip->i_di.di_uid, ip->i_di.di_gid); | |
377 | if (error) | |
378 | goto out_qunlock; | |
379 | ||
380 | al->al_requested = data_blocks + ind_blocks; | |
381 | error = gfs2_inplace_reserve(ip); | |
382 | if (error) | |
383 | goto out_qunlock; | |
384 | } | |
385 | ||
386 | rblocks = RES_DINODE + ind_blocks; | |
387 | if (gfs2_is_jdata(ip)) | |
388 | rblocks += data_blocks ? data_blocks : 1; | |
389 | if (ind_blocks || data_blocks) | |
390 | rblocks += RES_STATFS + RES_QUOTA; | |
391 | ||
392 | error = gfs2_trans_begin(sdp, rblocks, 0); | |
393 | if (error) | |
394 | goto out; | |
395 | ||
396 | if (gfs2_is_stuffed(ip)) { | |
397 | if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { | |
568f4c96 SW |
398 | error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, |
399 | page); | |
5c4e9e03 SW |
400 | if (error == 0) |
401 | goto prepare_write; | |
402 | } else if (!PageUptodate(page)) | |
b3b94faa | 403 | error = stuffed_readpage(ip, page); |
5c4e9e03 | 404 | goto out; |
18ec7d5c SW |
405 | } |
406 | ||
5c4e9e03 | 407 | prepare_write: |
18ec7d5c SW |
408 | error = block_prepare_write(page, from, to, gfs2_get_block); |
409 | ||
410 | out: | |
411 | if (error) { | |
412 | gfs2_trans_end(sdp); | |
413 | if (alloc_required) { | |
414 | gfs2_inplace_release(ip); | |
415 | out_qunlock: | |
416 | gfs2_quota_unlock(ip); | |
417 | out_alloc_put: | |
418 | gfs2_alloc_put(ip); | |
419 | } | |
420 | out_unlock: | |
421 | gfs2_glock_dq_m(1, &ip->i_gh); | |
422 | out_uninit: | |
423 | gfs2_holder_uninit(&ip->i_gh); | |
424 | } | |
b3b94faa DT |
425 | |
426 | return error; | |
427 | } | |
428 | ||
429 | /** | |
430 | * gfs2_commit_write - Commit write to a file | |
431 | * @file: The file to write to | |
432 | * @page: The page containing the data | |
433 | * @from: From (byte range within page) | |
434 | * @to: To (byte range within page) | |
435 | * | |
436 | * Returns: errno | |
437 | */ | |
438 | ||
439 | static int gfs2_commit_write(struct file *file, struct page *page, | |
440 | unsigned from, unsigned to) | |
441 | { | |
442 | struct inode *inode = page->mapping->host; | |
5c676f6d | 443 | struct gfs2_inode *ip = inode->u.generic_ip; |
b3b94faa | 444 | struct gfs2_sbd *sdp = ip->i_sbd; |
18ec7d5c SW |
445 | int error = -EOPNOTSUPP; |
446 | struct buffer_head *dibh; | |
447 | struct gfs2_alloc *al = &ip->i_alloc;; | |
b3b94faa | 448 | |
18ec7d5c SW |
449 | if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) |
450 | goto fail_nounlock; | |
451 | ||
452 | error = gfs2_meta_inode_buffer(ip, &dibh); | |
453 | if (error) | |
454 | goto fail_endtrans; | |
455 | ||
456 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); | |
457 | ||
b3b94faa | 458 | if (gfs2_is_stuffed(ip)) { |
b3b94faa DT |
459 | uint64_t file_size; |
460 | void *kaddr; | |
461 | ||
462 | file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to; | |
463 | ||
18ec7d5c | 464 | kaddr = kmap_atomic(page, KM_USER0); |
b3b94faa | 465 | memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from, |
18ec7d5c SW |
466 | (char *)kaddr + from, to - from); |
467 | kunmap_atomic(page, KM_USER0); | |
b3b94faa DT |
468 | |
469 | SetPageUptodate(page); | |
470 | ||
471 | if (inode->i_size < file_size) | |
472 | i_size_write(inode, file_size); | |
473 | } else { | |
568f4c96 SW |
474 | if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || |
475 | gfs2_is_jdata(ip)) | |
257f9b4e | 476 | gfs2_page_add_databufs(ip, page, from, to); |
b3b94faa DT |
477 | error = generic_commit_write(file, page, from, to); |
478 | if (error) | |
479 | goto fail; | |
480 | } | |
481 | ||
18ec7d5c SW |
482 | if (ip->i_di.di_size < inode->i_size) |
483 | ip->i_di.di_size = inode->i_size; | |
484 | ||
485 | gfs2_dinode_out(&ip->i_di, dibh->b_data); | |
486 | brelse(dibh); | |
487 | gfs2_trans_end(sdp); | |
488 | if (al->al_requested) { | |
489 | gfs2_inplace_release(ip); | |
490 | gfs2_quota_unlock(ip); | |
491 | gfs2_alloc_put(ip); | |
492 | } | |
493 | gfs2_glock_dq_m(1, &ip->i_gh); | |
494 | gfs2_holder_uninit(&ip->i_gh); | |
b3b94faa DT |
495 | return 0; |
496 | ||
18ec7d5c SW |
497 | fail: |
498 | brelse(dibh); | |
499 | fail_endtrans: | |
500 | gfs2_trans_end(sdp); | |
501 | if (al->al_requested) { | |
502 | gfs2_inplace_release(ip); | |
503 | gfs2_quota_unlock(ip); | |
504 | gfs2_alloc_put(ip); | |
505 | } | |
506 | gfs2_glock_dq_m(1, &ip->i_gh); | |
507 | gfs2_holder_uninit(&ip->i_gh); | |
508 | fail_nounlock: | |
b3b94faa | 509 | ClearPageUptodate(page); |
b3b94faa DT |
510 | return error; |
511 | } | |
512 | ||
513 | /** | |
514 | * gfs2_bmap - Block map function | |
515 | * @mapping: Address space info | |
516 | * @lblock: The block to map | |
517 | * | |
518 | * Returns: The disk address for the block or 0 on hole or error | |
519 | */ | |
520 | ||
521 | static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) | |
522 | { | |
5c676f6d | 523 | struct gfs2_inode *ip = mapping->host->u.generic_ip; |
b3b94faa DT |
524 | struct gfs2_holder i_gh; |
525 | sector_t dblock = 0; | |
526 | int error; | |
527 | ||
b3b94faa DT |
528 | error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); |
529 | if (error) | |
530 | return 0; | |
531 | ||
532 | if (!gfs2_is_stuffed(ip)) | |
4ff14670 | 533 | dblock = generic_block_bmap(mapping, lblock, gfs2_get_block); |
b3b94faa DT |
534 | |
535 | gfs2_glock_dq_uninit(&i_gh); | |
536 | ||
537 | return dblock; | |
538 | } | |
539 | ||
540 | static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh) | |
541 | { | |
64fb4eb7 | 542 | struct gfs2_bufdata *bd; |
b3b94faa DT |
543 | |
544 | gfs2_log_lock(sdp); | |
5c676f6d | 545 | bd = bh->b_private; |
64fb4eb7 SW |
546 | if (bd) { |
547 | bd->bd_bh = NULL; | |
5c676f6d | 548 | bh->b_private = NULL; |
b3b94faa DT |
549 | gfs2_log_unlock(sdp); |
550 | brelse(bh); | |
551 | } else | |
552 | gfs2_log_unlock(sdp); | |
553 | ||
554 | lock_buffer(bh); | |
555 | clear_buffer_dirty(bh); | |
556 | bh->b_bdev = NULL; | |
557 | clear_buffer_mapped(bh); | |
558 | clear_buffer_req(bh); | |
559 | clear_buffer_new(bh); | |
560 | clear_buffer_delay(bh); | |
561 | unlock_buffer(bh); | |
562 | } | |
563 | ||
8628de05 | 564 | static void gfs2_invalidatepage(struct page *page, unsigned long offset) |
b3b94faa | 565 | { |
5c676f6d | 566 | struct gfs2_sbd *sdp = page->mapping->host->i_sb->s_fs_info; |
b3b94faa DT |
567 | struct buffer_head *head, *bh, *next; |
568 | unsigned int curr_off = 0; | |
b3b94faa DT |
569 | |
570 | BUG_ON(!PageLocked(page)); | |
571 | if (!page_has_buffers(page)) | |
8628de05 | 572 | return; |
b3b94faa DT |
573 | |
574 | bh = head = page_buffers(page); | |
575 | do { | |
576 | unsigned int next_off = curr_off + bh->b_size; | |
577 | next = bh->b_this_page; | |
578 | ||
579 | if (offset <= curr_off) | |
580 | discard_buffer(sdp, bh); | |
581 | ||
582 | curr_off = next_off; | |
583 | bh = next; | |
584 | } while (bh != head); | |
585 | ||
586 | if (!offset) | |
8628de05 | 587 | try_to_release_page(page, 0); |
b3b94faa | 588 | |
8628de05 | 589 | return; |
b3b94faa DT |
590 | } |
591 | ||
d1665e41 SW |
592 | static ssize_t gfs2_direct_IO_write(struct kiocb *iocb, const struct iovec *iov, |
593 | loff_t offset, unsigned long nr_segs) | |
594 | { | |
595 | struct file *file = iocb->ki_filp; | |
596 | struct inode *inode = file->f_mapping->host; | |
5c676f6d | 597 | struct gfs2_inode *ip = inode->u.generic_ip; |
d1665e41 SW |
598 | struct gfs2_holder gh; |
599 | int rv; | |
600 | ||
601 | /* | |
602 | * Shared lock, even though its write, since we do no allocation | |
603 | * on this path. All we need change is atime. | |
604 | */ | |
605 | gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh); | |
606 | rv = gfs2_glock_nq_m_atime(1, &gh); | |
607 | if (rv) | |
608 | goto out; | |
609 | ||
610 | /* | |
611 | * Should we return an error here? I can't see that O_DIRECT for | |
612 | * a journaled file makes any sense. For now we'll silently fall | |
613 | * back to buffered I/O, likewise we do the same for stuffed | |
614 | * files since they are (a) small and (b) unaligned. | |
615 | */ | |
616 | if (gfs2_is_jdata(ip)) | |
617 | goto out; | |
618 | ||
619 | if (gfs2_is_stuffed(ip)) | |
620 | goto out; | |
621 | ||
622 | rv = __blockdev_direct_IO(WRITE, iocb, inode, inode->i_sb->s_bdev, | |
8628de05 | 623 | iov, offset, nr_segs, gfs2_get_block, |
d1665e41 SW |
624 | NULL, DIO_OWN_LOCKING); |
625 | out: | |
626 | gfs2_glock_dq_m(1, &gh); | |
627 | gfs2_holder_uninit(&gh); | |
628 | ||
629 | return rv; | |
630 | } | |
631 | ||
632 | /** | |
633 | * gfs2_direct_IO | |
634 | * | |
635 | * This is called with a shared lock already held for the read path. | |
636 | * Currently, no locks are held when the write path is called. | |
637 | */ | |
638 | static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, | |
639 | const struct iovec *iov, loff_t offset, | |
640 | unsigned long nr_segs) | |
b3b94faa DT |
641 | { |
642 | struct file *file = iocb->ki_filp; | |
643 | struct inode *inode = file->f_mapping->host; | |
5c676f6d | 644 | struct gfs2_inode *ip = inode->u.generic_ip; |
b3b94faa | 645 | struct gfs2_sbd *sdp = ip->i_sbd; |
b3b94faa | 646 | |
d1665e41 SW |
647 | if (rw == WRITE) |
648 | return gfs2_direct_IO_write(iocb, iov, offset, nr_segs); | |
b3b94faa | 649 | |
d1665e41 SW |
650 | if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) || |
651 | gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip))) | |
652 | return -EINVAL; | |
b3b94faa | 653 | |
d1665e41 | 654 | return __blockdev_direct_IO(READ, iocb, inode, inode->i_sb->s_bdev, iov, |
8628de05 | 655 | offset, nr_segs, gfs2_get_block, NULL, |
d1665e41 | 656 | DIO_OWN_LOCKING); |
b3b94faa DT |
657 | } |
658 | ||
659 | struct address_space_operations gfs2_file_aops = { | |
660 | .writepage = gfs2_writepage, | |
661 | .readpage = gfs2_readpage, | |
fd88de56 | 662 | .readpages = gfs2_readpages, |
b3b94faa DT |
663 | .sync_page = block_sync_page, |
664 | .prepare_write = gfs2_prepare_write, | |
665 | .commit_write = gfs2_commit_write, | |
666 | .bmap = gfs2_bmap, | |
667 | .invalidatepage = gfs2_invalidatepage, | |
668 | .direct_IO = gfs2_direct_IO, | |
669 | }; | |
670 |