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1e51764a AB |
1 | /* |
2 | * This file is part of UBIFS. | |
3 | * | |
4 | * Copyright (C) 2006-2008 Nokia Corporation. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License version 2 as published by | |
8 | * the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
13 | * more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along with | |
16 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
17 | * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | * | |
19 | * Authors: Artem Bityutskiy (Битюцкий Артём) | |
20 | * Adrian Hunter | |
21 | */ | |
22 | ||
23 | /* | |
873a64c7 | 24 | * This file implements VFS file and inode operations for regular files, device |
1e51764a AB |
25 | * nodes and symlinks as well as address space operations. |
26 | * | |
873a64c7 AB |
27 | * UBIFS uses 2 page flags: @PG_private and @PG_checked. @PG_private is set if |
28 | * the page is dirty and is used for optimization purposes - dirty pages are | |
29 | * not budgeted so the flag shows that 'ubifs_write_end()' should not release | |
30 | * the budget for this page. The @PG_checked flag is set if full budgeting is | |
31 | * required for the page e.g., when it corresponds to a file hole or it is | |
32 | * beyond the file size. The budgeting is done in 'ubifs_write_begin()', because | |
33 | * it is OK to fail in this function, and the budget is released in | |
34 | * 'ubifs_write_end()'. So the @PG_private and @PG_checked flags carry | |
35 | * information about how the page was budgeted, to make it possible to release | |
36 | * the budget properly. | |
1e51764a | 37 | * |
873a64c7 AB |
38 | * A thing to keep in mind: inode @i_mutex is locked in most VFS operations we |
39 | * implement. However, this is not true for 'ubifs_writepage()', which may be | |
5c57f20b AB |
40 | * called with @i_mutex unlocked. For example, when flusher thread is doing |
41 | * background write-back, it calls 'ubifs_writepage()' with unlocked @i_mutex. | |
42 | * At "normal" work-paths the @i_mutex is locked in 'ubifs_writepage()', e.g. | |
43 | * in the "sys_write -> alloc_pages -> direct reclaim path". So, in | |
44 | * 'ubifs_writepage()' we are only guaranteed that the page is locked. | |
1e51764a | 45 | * |
873a64c7 AB |
46 | * Similarly, @i_mutex is not always locked in 'ubifs_readpage()', e.g., the |
47 | * read-ahead path does not lock it ("sys_read -> generic_file_aio_read -> | |
eaff8079 | 48 | * ondemand_readahead -> readpage"). In case of readahead, @I_SYNC flag is not |
873a64c7 | 49 | * set as well. However, UBIFS disables readahead. |
1e51764a AB |
50 | */ |
51 | ||
52 | #include "ubifs.h" | |
53 | #include <linux/mount.h> | |
5a0e3ad6 | 54 | #include <linux/slab.h> |
4ac1c17b | 55 | #include <linux/migrate.h> |
1e51764a AB |
56 | |
57 | static int read_block(struct inode *inode, void *addr, unsigned int block, | |
58 | struct ubifs_data_node *dn) | |
59 | { | |
60 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
61 | int err, len, out_len; | |
62 | union ubifs_key key; | |
63 | unsigned int dlen; | |
64 | ||
65 | data_key_init(c, &key, inode->i_ino, block); | |
66 | err = ubifs_tnc_lookup(c, &key, dn); | |
67 | if (err) { | |
68 | if (err == -ENOENT) | |
69 | /* Not found, so it must be a hole */ | |
70 | memset(addr, 0, UBIFS_BLOCK_SIZE); | |
71 | return err; | |
72 | } | |
73 | ||
f92b9826 AB |
74 | ubifs_assert(le64_to_cpu(dn->ch.sqnum) > |
75 | ubifs_inode(inode)->creat_sqnum); | |
1e51764a AB |
76 | len = le32_to_cpu(dn->size); |
77 | if (len <= 0 || len > UBIFS_BLOCK_SIZE) | |
78 | goto dump; | |
79 | ||
80 | dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; | |
7799953b RW |
81 | |
82 | if (ubifs_crypt_is_encrypted(inode)) { | |
83 | err = ubifs_decrypt(inode, dn, &dlen, block); | |
84 | if (err) | |
85 | goto dump; | |
86 | } | |
87 | ||
1e51764a | 88 | out_len = UBIFS_BLOCK_SIZE; |
235c362b | 89 | err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len, |
1e51764a AB |
90 | le16_to_cpu(dn->compr_type)); |
91 | if (err || len != out_len) | |
92 | goto dump; | |
93 | ||
94 | /* | |
95 | * Data length can be less than a full block, even for blocks that are | |
96 | * not the last in the file (e.g., as a result of making a hole and | |
97 | * appending data). Ensure that the remainder is zeroed out. | |
98 | */ | |
99 | if (len < UBIFS_BLOCK_SIZE) | |
100 | memset(addr + len, 0, UBIFS_BLOCK_SIZE - len); | |
101 | ||
102 | return 0; | |
103 | ||
104 | dump: | |
235c362b | 105 | ubifs_err(c, "bad data node (block %u, inode %lu)", |
1e51764a | 106 | block, inode->i_ino); |
edf6be24 | 107 | ubifs_dump_node(c, dn); |
1e51764a AB |
108 | return -EINVAL; |
109 | } | |
110 | ||
111 | static int do_readpage(struct page *page) | |
112 | { | |
113 | void *addr; | |
114 | int err = 0, i; | |
115 | unsigned int block, beyond; | |
116 | struct ubifs_data_node *dn; | |
117 | struct inode *inode = page->mapping->host; | |
118 | loff_t i_size = i_size_read(inode); | |
119 | ||
120 | dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx", | |
121 | inode->i_ino, page->index, i_size, page->flags); | |
122 | ubifs_assert(!PageChecked(page)); | |
123 | ubifs_assert(!PagePrivate(page)); | |
124 | ||
125 | addr = kmap(page); | |
126 | ||
127 | block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
128 | beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT; | |
129 | if (block >= beyond) { | |
130 | /* Reading beyond inode */ | |
131 | SetPageChecked(page); | |
09cbfeaf | 132 | memset(addr, 0, PAGE_SIZE); |
1e51764a AB |
133 | goto out; |
134 | } | |
135 | ||
136 | dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS); | |
137 | if (!dn) { | |
138 | err = -ENOMEM; | |
139 | goto error; | |
140 | } | |
141 | ||
142 | i = 0; | |
143 | while (1) { | |
144 | int ret; | |
145 | ||
146 | if (block >= beyond) { | |
147 | /* Reading beyond inode */ | |
148 | err = -ENOENT; | |
149 | memset(addr, 0, UBIFS_BLOCK_SIZE); | |
150 | } else { | |
151 | ret = read_block(inode, addr, block, dn); | |
152 | if (ret) { | |
153 | err = ret; | |
154 | if (err != -ENOENT) | |
155 | break; | |
ed382d58 AH |
156 | } else if (block + 1 == beyond) { |
157 | int dlen = le32_to_cpu(dn->size); | |
158 | int ilen = i_size & (UBIFS_BLOCK_SIZE - 1); | |
159 | ||
160 | if (ilen && ilen < dlen) | |
161 | memset(addr + ilen, 0, dlen - ilen); | |
1e51764a AB |
162 | } |
163 | } | |
164 | if (++i >= UBIFS_BLOCKS_PER_PAGE) | |
165 | break; | |
166 | block += 1; | |
167 | addr += UBIFS_BLOCK_SIZE; | |
168 | } | |
169 | if (err) { | |
235c362b | 170 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1e51764a AB |
171 | if (err == -ENOENT) { |
172 | /* Not found, so it must be a hole */ | |
173 | SetPageChecked(page); | |
174 | dbg_gen("hole"); | |
175 | goto out_free; | |
176 | } | |
235c362b | 177 | ubifs_err(c, "cannot read page %lu of inode %lu, error %d", |
1e51764a AB |
178 | page->index, inode->i_ino, err); |
179 | goto error; | |
180 | } | |
181 | ||
182 | out_free: | |
183 | kfree(dn); | |
184 | out: | |
185 | SetPageUptodate(page); | |
186 | ClearPageError(page); | |
187 | flush_dcache_page(page); | |
188 | kunmap(page); | |
189 | return 0; | |
190 | ||
191 | error: | |
192 | kfree(dn); | |
193 | ClearPageUptodate(page); | |
194 | SetPageError(page); | |
195 | flush_dcache_page(page); | |
196 | kunmap(page); | |
197 | return err; | |
198 | } | |
199 | ||
200 | /** | |
201 | * release_new_page_budget - release budget of a new page. | |
202 | * @c: UBIFS file-system description object | |
203 | * | |
204 | * This is a helper function which releases budget corresponding to the budget | |
205 | * of one new page of data. | |
206 | */ | |
207 | static void release_new_page_budget(struct ubifs_info *c) | |
208 | { | |
209 | struct ubifs_budget_req req = { .recalculate = 1, .new_page = 1 }; | |
210 | ||
211 | ubifs_release_budget(c, &req); | |
212 | } | |
213 | ||
214 | /** | |
215 | * release_existing_page_budget - release budget of an existing page. | |
216 | * @c: UBIFS file-system description object | |
217 | * | |
218 | * This is a helper function which releases budget corresponding to the budget | |
219 | * of changing one one page of data which already exists on the flash media. | |
220 | */ | |
221 | static void release_existing_page_budget(struct ubifs_info *c) | |
222 | { | |
b137545c | 223 | struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget}; |
1e51764a AB |
224 | |
225 | ubifs_release_budget(c, &req); | |
226 | } | |
227 | ||
228 | static int write_begin_slow(struct address_space *mapping, | |
54566b2c NP |
229 | loff_t pos, unsigned len, struct page **pagep, |
230 | unsigned flags) | |
1e51764a AB |
231 | { |
232 | struct inode *inode = mapping->host; | |
233 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
09cbfeaf | 234 | pgoff_t index = pos >> PAGE_SHIFT; |
1e51764a AB |
235 | struct ubifs_budget_req req = { .new_page = 1 }; |
236 | int uninitialized_var(err), appending = !!(pos + len > inode->i_size); | |
237 | struct page *page; | |
238 | ||
239 | dbg_gen("ino %lu, pos %llu, len %u, i_size %lld", | |
240 | inode->i_ino, pos, len, inode->i_size); | |
241 | ||
242 | /* | |
243 | * At the slow path we have to budget before locking the page, because | |
244 | * budgeting may force write-back, which would wait on locked pages and | |
245 | * deadlock if we had the page locked. At this point we do not know | |
246 | * anything about the page, so assume that this is a new page which is | |
247 | * written to a hole. This corresponds to largest budget. Later the | |
248 | * budget will be amended if this is not true. | |
249 | */ | |
250 | if (appending) | |
251 | /* We are appending data, budget for inode change */ | |
252 | req.dirtied_ino = 1; | |
253 | ||
254 | err = ubifs_budget_space(c, &req); | |
255 | if (unlikely(err)) | |
256 | return err; | |
257 | ||
54566b2c | 258 | page = grab_cache_page_write_begin(mapping, index, flags); |
1e51764a AB |
259 | if (unlikely(!page)) { |
260 | ubifs_release_budget(c, &req); | |
261 | return -ENOMEM; | |
262 | } | |
263 | ||
264 | if (!PageUptodate(page)) { | |
09cbfeaf | 265 | if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) |
1e51764a AB |
266 | SetPageChecked(page); |
267 | else { | |
268 | err = do_readpage(page); | |
269 | if (err) { | |
270 | unlock_page(page); | |
09cbfeaf | 271 | put_page(page); |
789c8993 | 272 | ubifs_release_budget(c, &req); |
1e51764a AB |
273 | return err; |
274 | } | |
275 | } | |
276 | ||
277 | SetPageUptodate(page); | |
278 | ClearPageError(page); | |
279 | } | |
280 | ||
281 | if (PagePrivate(page)) | |
282 | /* | |
283 | * The page is dirty, which means it was budgeted twice: | |
284 | * o first time the budget was allocated by the task which | |
285 | * made the page dirty and set the PG_private flag; | |
286 | * o and then we budgeted for it for the second time at the | |
287 | * very beginning of this function. | |
288 | * | |
289 | * So what we have to do is to release the page budget we | |
290 | * allocated. | |
291 | */ | |
292 | release_new_page_budget(c); | |
293 | else if (!PageChecked(page)) | |
294 | /* | |
295 | * We are changing a page which already exists on the media. | |
296 | * This means that changing the page does not make the amount | |
297 | * of indexing information larger, and this part of the budget | |
298 | * which we have already acquired may be released. | |
299 | */ | |
300 | ubifs_convert_page_budget(c); | |
301 | ||
302 | if (appending) { | |
303 | struct ubifs_inode *ui = ubifs_inode(inode); | |
304 | ||
305 | /* | |
306 | * 'ubifs_write_end()' is optimized from the fast-path part of | |
307 | * 'ubifs_write_begin()' and expects the @ui_mutex to be locked | |
308 | * if data is appended. | |
309 | */ | |
310 | mutex_lock(&ui->ui_mutex); | |
311 | if (ui->dirty) | |
312 | /* | |
313 | * The inode is dirty already, so we may free the | |
314 | * budget we allocated. | |
315 | */ | |
316 | ubifs_release_dirty_inode_budget(c, ui); | |
317 | } | |
318 | ||
319 | *pagep = page; | |
320 | return 0; | |
321 | } | |
322 | ||
323 | /** | |
324 | * allocate_budget - allocate budget for 'ubifs_write_begin()'. | |
325 | * @c: UBIFS file-system description object | |
326 | * @page: page to allocate budget for | |
327 | * @ui: UBIFS inode object the page belongs to | |
328 | * @appending: non-zero if the page is appended | |
329 | * | |
330 | * This is a helper function for 'ubifs_write_begin()' which allocates budget | |
331 | * for the operation. The budget is allocated differently depending on whether | |
332 | * this is appending, whether the page is dirty or not, and so on. This | |
333 | * function leaves the @ui->ui_mutex locked in case of appending. Returns zero | |
334 | * in case of success and %-ENOSPC in case of failure. | |
335 | */ | |
336 | static int allocate_budget(struct ubifs_info *c, struct page *page, | |
337 | struct ubifs_inode *ui, int appending) | |
338 | { | |
339 | struct ubifs_budget_req req = { .fast = 1 }; | |
340 | ||
341 | if (PagePrivate(page)) { | |
342 | if (!appending) | |
343 | /* | |
344 | * The page is dirty and we are not appending, which | |
345 | * means no budget is needed at all. | |
346 | */ | |
347 | return 0; | |
348 | ||
349 | mutex_lock(&ui->ui_mutex); | |
350 | if (ui->dirty) | |
351 | /* | |
352 | * The page is dirty and we are appending, so the inode | |
353 | * has to be marked as dirty. However, it is already | |
354 | * dirty, so we do not need any budget. We may return, | |
355 | * but @ui->ui_mutex hast to be left locked because we | |
356 | * should prevent write-back from flushing the inode | |
357 | * and freeing the budget. The lock will be released in | |
358 | * 'ubifs_write_end()'. | |
359 | */ | |
360 | return 0; | |
361 | ||
362 | /* | |
363 | * The page is dirty, we are appending, the inode is clean, so | |
364 | * we need to budget the inode change. | |
365 | */ | |
366 | req.dirtied_ino = 1; | |
367 | } else { | |
368 | if (PageChecked(page)) | |
369 | /* | |
370 | * The page corresponds to a hole and does not | |
371 | * exist on the media. So changing it makes | |
372 | * make the amount of indexing information | |
373 | * larger, and we have to budget for a new | |
374 | * page. | |
375 | */ | |
376 | req.new_page = 1; | |
377 | else | |
378 | /* | |
379 | * Not a hole, the change will not add any new | |
380 | * indexing information, budget for page | |
381 | * change. | |
382 | */ | |
383 | req.dirtied_page = 1; | |
384 | ||
385 | if (appending) { | |
386 | mutex_lock(&ui->ui_mutex); | |
387 | if (!ui->dirty) | |
388 | /* | |
389 | * The inode is clean but we will have to mark | |
390 | * it as dirty because we are appending. This | |
391 | * needs a budget. | |
392 | */ | |
393 | req.dirtied_ino = 1; | |
394 | } | |
395 | } | |
396 | ||
397 | return ubifs_budget_space(c, &req); | |
398 | } | |
399 | ||
400 | /* | |
401 | * This function is called when a page of data is going to be written. Since | |
402 | * the page of data will not necessarily go to the flash straight away, UBIFS | |
403 | * has to reserve space on the media for it, which is done by means of | |
404 | * budgeting. | |
405 | * | |
406 | * This is the hot-path of the file-system and we are trying to optimize it as | |
407 | * much as possible. For this reasons it is split on 2 parts - slow and fast. | |
408 | * | |
409 | * There many budgeting cases: | |
410 | * o a new page is appended - we have to budget for a new page and for | |
411 | * changing the inode; however, if the inode is already dirty, there is | |
412 | * no need to budget for it; | |
413 | * o an existing clean page is changed - we have budget for it; if the page | |
414 | * does not exist on the media (a hole), we have to budget for a new | |
415 | * page; otherwise, we may budget for changing an existing page; the | |
416 | * difference between these cases is that changing an existing page does | |
417 | * not introduce anything new to the FS indexing information, so it does | |
418 | * not grow, and smaller budget is acquired in this case; | |
419 | * o an existing dirty page is changed - no need to budget at all, because | |
420 | * the page budget has been acquired by earlier, when the page has been | |
421 | * marked dirty. | |
422 | * | |
423 | * UBIFS budgeting sub-system may force write-back if it thinks there is no | |
424 | * space to reserve. This imposes some locking restrictions and makes it | |
425 | * impossible to take into account the above cases, and makes it impossible to | |
426 | * optimize budgeting. | |
427 | * | |
428 | * The solution for this is that the fast path of 'ubifs_write_begin()' assumes | |
429 | * there is a plenty of flash space and the budget will be acquired quickly, | |
430 | * without forcing write-back. The slow path does not make this assumption. | |
431 | */ | |
432 | static int ubifs_write_begin(struct file *file, struct address_space *mapping, | |
433 | loff_t pos, unsigned len, unsigned flags, | |
434 | struct page **pagep, void **fsdata) | |
435 | { | |
436 | struct inode *inode = mapping->host; | |
437 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
438 | struct ubifs_inode *ui = ubifs_inode(inode); | |
09cbfeaf | 439 | pgoff_t index = pos >> PAGE_SHIFT; |
1e51764a | 440 | int uninitialized_var(err), appending = !!(pos + len > inode->i_size); |
f55aa591 | 441 | int skipped_read = 0; |
1e51764a AB |
442 | struct page *page; |
443 | ||
1e51764a | 444 | ubifs_assert(ubifs_inode(inode)->ui_size == inode->i_size); |
2ef13294 | 445 | ubifs_assert(!c->ro_media && !c->ro_mount); |
1e51764a | 446 | |
2680d722 | 447 | if (unlikely(c->ro_error)) |
1e51764a AB |
448 | return -EROFS; |
449 | ||
450 | /* Try out the fast-path part first */ | |
54566b2c | 451 | page = grab_cache_page_write_begin(mapping, index, flags); |
1e51764a AB |
452 | if (unlikely(!page)) |
453 | return -ENOMEM; | |
454 | ||
455 | if (!PageUptodate(page)) { | |
456 | /* The page is not loaded from the flash */ | |
09cbfeaf | 457 | if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) { |
1e51764a AB |
458 | /* |
459 | * We change whole page so no need to load it. But we | |
6ed09c34 AB |
460 | * do not know whether this page exists on the media or |
461 | * not, so we assume the latter because it requires | |
462 | * larger budget. The assumption is that it is better | |
463 | * to budget a bit more than to read the page from the | |
464 | * media. Thus, we are setting the @PG_checked flag | |
465 | * here. | |
1e51764a AB |
466 | */ |
467 | SetPageChecked(page); | |
f55aa591 AH |
468 | skipped_read = 1; |
469 | } else { | |
1e51764a AB |
470 | err = do_readpage(page); |
471 | if (err) { | |
472 | unlock_page(page); | |
09cbfeaf | 473 | put_page(page); |
1e51764a AB |
474 | return err; |
475 | } | |
476 | } | |
477 | ||
478 | SetPageUptodate(page); | |
479 | ClearPageError(page); | |
480 | } | |
481 | ||
482 | err = allocate_budget(c, page, ui, appending); | |
483 | if (unlikely(err)) { | |
484 | ubifs_assert(err == -ENOSPC); | |
f55aa591 AH |
485 | /* |
486 | * If we skipped reading the page because we were going to | |
487 | * write all of it, then it is not up to date. | |
488 | */ | |
489 | if (skipped_read) { | |
490 | ClearPageChecked(page); | |
491 | ClearPageUptodate(page); | |
492 | } | |
1e51764a AB |
493 | /* |
494 | * Budgeting failed which means it would have to force | |
495 | * write-back but didn't, because we set the @fast flag in the | |
496 | * request. Write-back cannot be done now, while we have the | |
497 | * page locked, because it would deadlock. Unlock and free | |
498 | * everything and fall-back to slow-path. | |
499 | */ | |
500 | if (appending) { | |
501 | ubifs_assert(mutex_is_locked(&ui->ui_mutex)); | |
502 | mutex_unlock(&ui->ui_mutex); | |
503 | } | |
504 | unlock_page(page); | |
09cbfeaf | 505 | put_page(page); |
1e51764a | 506 | |
54566b2c | 507 | return write_begin_slow(mapping, pos, len, pagep, flags); |
1e51764a AB |
508 | } |
509 | ||
510 | /* | |
873a64c7 AB |
511 | * Whee, we acquired budgeting quickly - without involving |
512 | * garbage-collection, committing or forcing write-back. We return | |
1e51764a AB |
513 | * with @ui->ui_mutex locked if we are appending pages, and unlocked |
514 | * otherwise. This is an optimization (slightly hacky though). | |
515 | */ | |
516 | *pagep = page; | |
517 | return 0; | |
518 | ||
519 | } | |
520 | ||
521 | /** | |
522 | * cancel_budget - cancel budget. | |
523 | * @c: UBIFS file-system description object | |
524 | * @page: page to cancel budget for | |
525 | * @ui: UBIFS inode object the page belongs to | |
526 | * @appending: non-zero if the page is appended | |
527 | * | |
528 | * This is a helper function for a page write operation. It unlocks the | |
529 | * @ui->ui_mutex in case of appending. | |
530 | */ | |
531 | static void cancel_budget(struct ubifs_info *c, struct page *page, | |
532 | struct ubifs_inode *ui, int appending) | |
533 | { | |
534 | if (appending) { | |
535 | if (!ui->dirty) | |
536 | ubifs_release_dirty_inode_budget(c, ui); | |
537 | mutex_unlock(&ui->ui_mutex); | |
538 | } | |
539 | if (!PagePrivate(page)) { | |
540 | if (PageChecked(page)) | |
541 | release_new_page_budget(c); | |
542 | else | |
543 | release_existing_page_budget(c); | |
544 | } | |
545 | } | |
546 | ||
547 | static int ubifs_write_end(struct file *file, struct address_space *mapping, | |
548 | loff_t pos, unsigned len, unsigned copied, | |
549 | struct page *page, void *fsdata) | |
550 | { | |
551 | struct inode *inode = mapping->host; | |
552 | struct ubifs_inode *ui = ubifs_inode(inode); | |
553 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
554 | loff_t end_pos = pos + len; | |
555 | int appending = !!(end_pos > inode->i_size); | |
556 | ||
557 | dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld", | |
558 | inode->i_ino, pos, page->index, len, copied, inode->i_size); | |
559 | ||
09cbfeaf | 560 | if (unlikely(copied < len && len == PAGE_SIZE)) { |
1e51764a AB |
561 | /* |
562 | * VFS copied less data to the page that it intended and | |
563 | * declared in its '->write_begin()' call via the @len | |
564 | * argument. If the page was not up-to-date, and @len was | |
ea1754a0 | 565 | * @PAGE_SIZE, the 'ubifs_write_begin()' function did |
1e51764a AB |
566 | * not load it from the media (for optimization reasons). This |
567 | * means that part of the page contains garbage. So read the | |
568 | * page now. | |
569 | */ | |
570 | dbg_gen("copied %d instead of %d, read page and repeat", | |
571 | copied, len); | |
572 | cancel_budget(c, page, ui, appending); | |
6ed09c34 | 573 | ClearPageChecked(page); |
1e51764a AB |
574 | |
575 | /* | |
576 | * Return 0 to force VFS to repeat the whole operation, or the | |
873a64c7 | 577 | * error code if 'do_readpage()' fails. |
1e51764a AB |
578 | */ |
579 | copied = do_readpage(page); | |
580 | goto out; | |
581 | } | |
582 | ||
583 | if (!PagePrivate(page)) { | |
584 | SetPagePrivate(page); | |
585 | atomic_long_inc(&c->dirty_pg_cnt); | |
586 | __set_page_dirty_nobuffers(page); | |
587 | } | |
588 | ||
589 | if (appending) { | |
590 | i_size_write(inode, end_pos); | |
591 | ui->ui_size = end_pos; | |
592 | /* | |
593 | * Note, we do not set @I_DIRTY_PAGES (which means that the | |
594 | * inode has dirty pages), this has been done in | |
595 | * '__set_page_dirty_nobuffers()'. | |
596 | */ | |
597 | __mark_inode_dirty(inode, I_DIRTY_DATASYNC); | |
598 | ubifs_assert(mutex_is_locked(&ui->ui_mutex)); | |
599 | mutex_unlock(&ui->ui_mutex); | |
600 | } | |
601 | ||
602 | out: | |
603 | unlock_page(page); | |
09cbfeaf | 604 | put_page(page); |
1e51764a AB |
605 | return copied; |
606 | } | |
607 | ||
4793e7c5 AH |
608 | /** |
609 | * populate_page - copy data nodes into a page for bulk-read. | |
610 | * @c: UBIFS file-system description object | |
611 | * @page: page | |
612 | * @bu: bulk-read information | |
613 | * @n: next zbranch slot | |
614 | * | |
615 | * This function returns %0 on success and a negative error code on failure. | |
616 | */ | |
617 | static int populate_page(struct ubifs_info *c, struct page *page, | |
618 | struct bu_info *bu, int *n) | |
619 | { | |
5c0013c1 | 620 | int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0; |
4793e7c5 AH |
621 | struct inode *inode = page->mapping->host; |
622 | loff_t i_size = i_size_read(inode); | |
623 | unsigned int page_block; | |
624 | void *addr, *zaddr; | |
625 | pgoff_t end_index; | |
626 | ||
627 | dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx", | |
628 | inode->i_ino, page->index, i_size, page->flags); | |
629 | ||
630 | addr = zaddr = kmap(page); | |
631 | ||
09cbfeaf | 632 | end_index = (i_size - 1) >> PAGE_SHIFT; |
4793e7c5 | 633 | if (!i_size || page->index > end_index) { |
5c0013c1 | 634 | hole = 1; |
09cbfeaf | 635 | memset(addr, 0, PAGE_SIZE); |
4793e7c5 AH |
636 | goto out_hole; |
637 | } | |
638 | ||
639 | page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
640 | while (1) { | |
641 | int err, len, out_len, dlen; | |
642 | ||
5c0013c1 AH |
643 | if (nn >= bu->cnt) { |
644 | hole = 1; | |
4793e7c5 | 645 | memset(addr, 0, UBIFS_BLOCK_SIZE); |
5c0013c1 | 646 | } else if (key_block(c, &bu->zbranch[nn].key) == page_block) { |
4793e7c5 AH |
647 | struct ubifs_data_node *dn; |
648 | ||
649 | dn = bu->buf + (bu->zbranch[nn].offs - offs); | |
650 | ||
0ecb9529 | 651 | ubifs_assert(le64_to_cpu(dn->ch.sqnum) > |
4793e7c5 AH |
652 | ubifs_inode(inode)->creat_sqnum); |
653 | ||
654 | len = le32_to_cpu(dn->size); | |
655 | if (len <= 0 || len > UBIFS_BLOCK_SIZE) | |
656 | goto out_err; | |
657 | ||
658 | dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; | |
659 | out_len = UBIFS_BLOCK_SIZE; | |
7799953b RW |
660 | |
661 | if (ubifs_crypt_is_encrypted(inode)) { | |
662 | err = ubifs_decrypt(inode, dn, &dlen, page_block); | |
663 | if (err) | |
664 | goto out_err; | |
665 | } | |
666 | ||
235c362b | 667 | err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len, |
4793e7c5 AH |
668 | le16_to_cpu(dn->compr_type)); |
669 | if (err || len != out_len) | |
670 | goto out_err; | |
671 | ||
672 | if (len < UBIFS_BLOCK_SIZE) | |
673 | memset(addr + len, 0, UBIFS_BLOCK_SIZE - len); | |
674 | ||
675 | nn += 1; | |
4793e7c5 | 676 | read = (i << UBIFS_BLOCK_SHIFT) + len; |
5c0013c1 AH |
677 | } else if (key_block(c, &bu->zbranch[nn].key) < page_block) { |
678 | nn += 1; | |
679 | continue; | |
680 | } else { | |
681 | hole = 1; | |
682 | memset(addr, 0, UBIFS_BLOCK_SIZE); | |
4793e7c5 AH |
683 | } |
684 | if (++i >= UBIFS_BLOCKS_PER_PAGE) | |
685 | break; | |
686 | addr += UBIFS_BLOCK_SIZE; | |
687 | page_block += 1; | |
688 | } | |
689 | ||
690 | if (end_index == page->index) { | |
09cbfeaf | 691 | int len = i_size & (PAGE_SIZE - 1); |
4793e7c5 | 692 | |
ed382d58 | 693 | if (len && len < read) |
4793e7c5 AH |
694 | memset(zaddr + len, 0, read - len); |
695 | } | |
696 | ||
697 | out_hole: | |
698 | if (hole) { | |
699 | SetPageChecked(page); | |
700 | dbg_gen("hole"); | |
701 | } | |
702 | ||
703 | SetPageUptodate(page); | |
704 | ClearPageError(page); | |
705 | flush_dcache_page(page); | |
706 | kunmap(page); | |
707 | *n = nn; | |
708 | return 0; | |
709 | ||
710 | out_err: | |
711 | ClearPageUptodate(page); | |
712 | SetPageError(page); | |
713 | flush_dcache_page(page); | |
714 | kunmap(page); | |
235c362b | 715 | ubifs_err(c, "bad data node (block %u, inode %lu)", |
4793e7c5 AH |
716 | page_block, inode->i_ino); |
717 | return -EINVAL; | |
718 | } | |
719 | ||
720 | /** | |
721 | * ubifs_do_bulk_read - do bulk-read. | |
722 | * @c: UBIFS file-system description object | |
6c0c42cd AB |
723 | * @bu: bulk-read information |
724 | * @page1: first page to read | |
4793e7c5 AH |
725 | * |
726 | * This function returns %1 if the bulk-read is done, otherwise %0 is returned. | |
727 | */ | |
6c0c42cd AB |
728 | static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu, |
729 | struct page *page1) | |
4793e7c5 AH |
730 | { |
731 | pgoff_t offset = page1->index, end_index; | |
732 | struct address_space *mapping = page1->mapping; | |
733 | struct inode *inode = mapping->host; | |
734 | struct ubifs_inode *ui = ubifs_inode(inode); | |
4793e7c5 | 735 | int err, page_idx, page_cnt, ret = 0, n = 0; |
6c0c42cd | 736 | int allocate = bu->buf ? 0 : 1; |
4793e7c5 AH |
737 | loff_t isize; |
738 | ||
4793e7c5 AH |
739 | err = ubifs_tnc_get_bu_keys(c, bu); |
740 | if (err) | |
741 | goto out_warn; | |
742 | ||
743 | if (bu->eof) { | |
744 | /* Turn off bulk-read at the end of the file */ | |
745 | ui->read_in_a_row = 1; | |
746 | ui->bulk_read = 0; | |
747 | } | |
748 | ||
749 | page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
750 | if (!page_cnt) { | |
751 | /* | |
752 | * This happens when there are multiple blocks per page and the | |
753 | * blocks for the first page we are looking for, are not | |
754 | * together. If all the pages were like this, bulk-read would | |
755 | * reduce performance, so we turn it off for a while. | |
756 | */ | |
6c0c42cd | 757 | goto out_bu_off; |
4793e7c5 AH |
758 | } |
759 | ||
760 | if (bu->cnt) { | |
6c0c42cd AB |
761 | if (allocate) { |
762 | /* | |
763 | * Allocate bulk-read buffer depending on how many data | |
764 | * nodes we are going to read. | |
765 | */ | |
766 | bu->buf_len = bu->zbranch[bu->cnt - 1].offs + | |
767 | bu->zbranch[bu->cnt - 1].len - | |
768 | bu->zbranch[0].offs; | |
769 | ubifs_assert(bu->buf_len > 0); | |
770 | ubifs_assert(bu->buf_len <= c->leb_size); | |
771 | bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN); | |
772 | if (!bu->buf) | |
773 | goto out_bu_off; | |
774 | } | |
775 | ||
4793e7c5 AH |
776 | err = ubifs_tnc_bulk_read(c, bu); |
777 | if (err) | |
778 | goto out_warn; | |
779 | } | |
780 | ||
781 | err = populate_page(c, page1, bu, &n); | |
782 | if (err) | |
783 | goto out_warn; | |
784 | ||
785 | unlock_page(page1); | |
786 | ret = 1; | |
787 | ||
788 | isize = i_size_read(inode); | |
789 | if (isize == 0) | |
790 | goto out_free; | |
09cbfeaf | 791 | end_index = ((isize - 1) >> PAGE_SHIFT); |
4793e7c5 AH |
792 | |
793 | for (page_idx = 1; page_idx < page_cnt; page_idx++) { | |
794 | pgoff_t page_offset = offset + page_idx; | |
795 | struct page *page; | |
796 | ||
797 | if (page_offset > end_index) | |
798 | break; | |
799 | page = find_or_create_page(mapping, page_offset, | |
800 | GFP_NOFS | __GFP_COLD); | |
801 | if (!page) | |
802 | break; | |
803 | if (!PageUptodate(page)) | |
804 | err = populate_page(c, page, bu, &n); | |
805 | unlock_page(page); | |
09cbfeaf | 806 | put_page(page); |
4793e7c5 AH |
807 | if (err) |
808 | break; | |
809 | } | |
810 | ||
811 | ui->last_page_read = offset + page_idx - 1; | |
812 | ||
813 | out_free: | |
6c0c42cd AB |
814 | if (allocate) |
815 | kfree(bu->buf); | |
4793e7c5 AH |
816 | return ret; |
817 | ||
818 | out_warn: | |
235c362b | 819 | ubifs_warn(c, "ignoring error %d and skipping bulk-read", err); |
4793e7c5 | 820 | goto out_free; |
6c0c42cd AB |
821 | |
822 | out_bu_off: | |
823 | ui->read_in_a_row = ui->bulk_read = 0; | |
824 | goto out_free; | |
4793e7c5 AH |
825 | } |
826 | ||
827 | /** | |
828 | * ubifs_bulk_read - determine whether to bulk-read and, if so, do it. | |
829 | * @page: page from which to start bulk-read. | |
830 | * | |
831 | * Some flash media are capable of reading sequentially at faster rates. UBIFS | |
832 | * bulk-read facility is designed to take advantage of that, by reading in one | |
833 | * go consecutive data nodes that are also located consecutively in the same | |
834 | * LEB. This function returns %1 if a bulk-read is done and %0 otherwise. | |
835 | */ | |
836 | static int ubifs_bulk_read(struct page *page) | |
837 | { | |
838 | struct inode *inode = page->mapping->host; | |
839 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
840 | struct ubifs_inode *ui = ubifs_inode(inode); | |
841 | pgoff_t index = page->index, last_page_read = ui->last_page_read; | |
6c0c42cd | 842 | struct bu_info *bu; |
3477d204 | 843 | int err = 0, allocated = 0; |
4793e7c5 AH |
844 | |
845 | ui->last_page_read = index; | |
4793e7c5 AH |
846 | if (!c->bulk_read) |
847 | return 0; | |
6c0c42cd | 848 | |
4793e7c5 | 849 | /* |
3477d204 AB |
850 | * Bulk-read is protected by @ui->ui_mutex, but it is an optimization, |
851 | * so don't bother if we cannot lock the mutex. | |
4793e7c5 AH |
852 | */ |
853 | if (!mutex_trylock(&ui->ui_mutex)) | |
854 | return 0; | |
6c0c42cd | 855 | |
4793e7c5 AH |
856 | if (index != last_page_read + 1) { |
857 | /* Turn off bulk-read if we stop reading sequentially */ | |
858 | ui->read_in_a_row = 1; | |
859 | if (ui->bulk_read) | |
860 | ui->bulk_read = 0; | |
861 | goto out_unlock; | |
862 | } | |
6c0c42cd | 863 | |
4793e7c5 AH |
864 | if (!ui->bulk_read) { |
865 | ui->read_in_a_row += 1; | |
866 | if (ui->read_in_a_row < 3) | |
867 | goto out_unlock; | |
868 | /* Three reads in a row, so switch on bulk-read */ | |
869 | ui->bulk_read = 1; | |
870 | } | |
6c0c42cd | 871 | |
3477d204 AB |
872 | /* |
873 | * If possible, try to use pre-allocated bulk-read information, which | |
874 | * is protected by @c->bu_mutex. | |
875 | */ | |
876 | if (mutex_trylock(&c->bu_mutex)) | |
877 | bu = &c->bu; | |
878 | else { | |
879 | bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN); | |
880 | if (!bu) | |
881 | goto out_unlock; | |
882 | ||
883 | bu->buf = NULL; | |
884 | allocated = 1; | |
885 | } | |
6c0c42cd | 886 | |
6c0c42cd AB |
887 | bu->buf_len = c->max_bu_buf_len; |
888 | data_key_init(c, &bu->key, inode->i_ino, | |
889 | page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT); | |
6c0c42cd | 890 | err = ubifs_do_bulk_read(c, bu, page); |
3477d204 AB |
891 | |
892 | if (!allocated) | |
893 | mutex_unlock(&c->bu_mutex); | |
894 | else | |
895 | kfree(bu); | |
6c0c42cd | 896 | |
4793e7c5 AH |
897 | out_unlock: |
898 | mutex_unlock(&ui->ui_mutex); | |
6c0c42cd | 899 | return err; |
4793e7c5 AH |
900 | } |
901 | ||
1e51764a AB |
902 | static int ubifs_readpage(struct file *file, struct page *page) |
903 | { | |
4793e7c5 AH |
904 | if (ubifs_bulk_read(page)) |
905 | return 0; | |
1e51764a AB |
906 | do_readpage(page); |
907 | unlock_page(page); | |
908 | return 0; | |
909 | } | |
910 | ||
911 | static int do_writepage(struct page *page, int len) | |
912 | { | |
913 | int err = 0, i, blen; | |
914 | unsigned int block; | |
915 | void *addr; | |
916 | union ubifs_key key; | |
917 | struct inode *inode = page->mapping->host; | |
918 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
919 | ||
920 | #ifdef UBIFS_DEBUG | |
a0fd5951 | 921 | struct ubifs_inode *ui = ubifs_inode(inode); |
1e51764a | 922 | spin_lock(&ui->ui_lock); |
09cbfeaf | 923 | ubifs_assert(page->index <= ui->synced_i_size >> PAGE_SHIFT); |
1e51764a AB |
924 | spin_unlock(&ui->ui_lock); |
925 | #endif | |
926 | ||
927 | /* Update radix tree tags */ | |
928 | set_page_writeback(page); | |
929 | ||
930 | addr = kmap(page); | |
931 | block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
932 | i = 0; | |
933 | while (len) { | |
934 | blen = min_t(int, len, UBIFS_BLOCK_SIZE); | |
935 | data_key_init(c, &key, inode->i_ino, block); | |
936 | err = ubifs_jnl_write_data(c, inode, &key, addr, blen); | |
937 | if (err) | |
938 | break; | |
939 | if (++i >= UBIFS_BLOCKS_PER_PAGE) | |
940 | break; | |
941 | block += 1; | |
942 | addr += blen; | |
943 | len -= blen; | |
944 | } | |
945 | if (err) { | |
946 | SetPageError(page); | |
235c362b | 947 | ubifs_err(c, "cannot write page %lu of inode %lu, error %d", |
1e51764a AB |
948 | page->index, inode->i_ino, err); |
949 | ubifs_ro_mode(c, err); | |
950 | } | |
951 | ||
952 | ubifs_assert(PagePrivate(page)); | |
953 | if (PageChecked(page)) | |
954 | release_new_page_budget(c); | |
955 | else | |
956 | release_existing_page_budget(c); | |
957 | ||
958 | atomic_long_dec(&c->dirty_pg_cnt); | |
959 | ClearPagePrivate(page); | |
960 | ClearPageChecked(page); | |
961 | ||
962 | kunmap(page); | |
963 | unlock_page(page); | |
964 | end_page_writeback(page); | |
965 | return err; | |
966 | } | |
967 | ||
968 | /* | |
969 | * When writing-back dirty inodes, VFS first writes-back pages belonging to the | |
970 | * inode, then the inode itself. For UBIFS this may cause a problem. Consider a | |
971 | * situation when a we have an inode with size 0, then a megabyte of data is | |
972 | * appended to the inode, then write-back starts and flushes some amount of the | |
973 | * dirty pages, the journal becomes full, commit happens and finishes, and then | |
974 | * an unclean reboot happens. When the file system is mounted next time, the | |
975 | * inode size would still be 0, but there would be many pages which are beyond | |
976 | * the inode size, they would be indexed and consume flash space. Because the | |
977 | * journal has been committed, the replay would not be able to detect this | |
978 | * situation and correct the inode size. This means UBIFS would have to scan | |
979 | * whole index and correct all inode sizes, which is long an unacceptable. | |
980 | * | |
981 | * To prevent situations like this, UBIFS writes pages back only if they are | |
7d4e9ccb | 982 | * within the last synchronized inode size, i.e. the size which has been |
1e51764a AB |
983 | * written to the flash media last time. Otherwise, UBIFS forces inode |
984 | * write-back, thus making sure the on-flash inode contains current inode size, | |
985 | * and then keeps writing pages back. | |
986 | * | |
987 | * Some locking issues explanation. 'ubifs_writepage()' first is called with | |
988 | * the page locked, and it locks @ui_mutex. However, write-back does take inode | |
989 | * @i_mutex, which means other VFS operations may be run on this inode at the | |
990 | * same time. And the problematic one is truncation to smaller size, from where | |
c4361570 AB |
991 | * we have to call 'truncate_setsize()', which first changes @inode->i_size, |
992 | * then drops the truncated pages. And while dropping the pages, it takes the | |
993 | * page lock. This means that 'do_truncation()' cannot call 'truncate_setsize()' | |
994 | * with @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'. | |
995 | * This means that @inode->i_size is changed while @ui_mutex is unlocked. | |
1e51764a | 996 | * |
2c27c65e CH |
997 | * XXX(truncate): with the new truncate sequence this is not true anymore, |
998 | * and the calls to truncate_setsize can be move around freely. They should | |
999 | * be moved to the very end of the truncate sequence. | |
15c6fd97 | 1000 | * |
1e51764a AB |
1001 | * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond |
1002 | * inode size. How do we do this if @inode->i_size may became smaller while we | |
1003 | * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the | |
1004 | * @ui->ui_isize "shadow" field which UBIFS uses instead of @inode->i_size | |
1005 | * internally and updates it under @ui_mutex. | |
1006 | * | |
1007 | * Q: why we do not worry that if we race with truncation, we may end up with a | |
1008 | * situation when the inode is truncated while we are in the middle of | |
1009 | * 'do_writepage()', so we do write beyond inode size? | |
1010 | * A: If we are in the middle of 'do_writepage()', truncation would be locked | |
1011 | * on the page lock and it would not write the truncated inode node to the | |
1012 | * journal before we have finished. | |
1013 | */ | |
1014 | static int ubifs_writepage(struct page *page, struct writeback_control *wbc) | |
1015 | { | |
1016 | struct inode *inode = page->mapping->host; | |
1017 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1018 | loff_t i_size = i_size_read(inode), synced_i_size; | |
09cbfeaf KS |
1019 | pgoff_t end_index = i_size >> PAGE_SHIFT; |
1020 | int err, len = i_size & (PAGE_SIZE - 1); | |
1e51764a AB |
1021 | void *kaddr; |
1022 | ||
1023 | dbg_gen("ino %lu, pg %lu, pg flags %#lx", | |
1024 | inode->i_ino, page->index, page->flags); | |
1025 | ubifs_assert(PagePrivate(page)); | |
1026 | ||
1027 | /* Is the page fully outside @i_size? (truncate in progress) */ | |
1028 | if (page->index > end_index || (page->index == end_index && !len)) { | |
1029 | err = 0; | |
1030 | goto out_unlock; | |
1031 | } | |
1032 | ||
1033 | spin_lock(&ui->ui_lock); | |
1034 | synced_i_size = ui->synced_i_size; | |
1035 | spin_unlock(&ui->ui_lock); | |
1036 | ||
1037 | /* Is the page fully inside @i_size? */ | |
1038 | if (page->index < end_index) { | |
09cbfeaf | 1039 | if (page->index >= synced_i_size >> PAGE_SHIFT) { |
a9185b41 | 1040 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a AB |
1041 | if (err) |
1042 | goto out_unlock; | |
1043 | /* | |
1044 | * The inode has been written, but the write-buffer has | |
1045 | * not been synchronized, so in case of an unclean | |
1046 | * reboot we may end up with some pages beyond inode | |
1047 | * size, but they would be in the journal (because | |
1048 | * commit flushes write buffers) and recovery would deal | |
1049 | * with this. | |
1050 | */ | |
1051 | } | |
09cbfeaf | 1052 | return do_writepage(page, PAGE_SIZE); |
1e51764a AB |
1053 | } |
1054 | ||
1055 | /* | |
1056 | * The page straddles @i_size. It must be zeroed out on each and every | |
1057 | * writepage invocation because it may be mmapped. "A file is mapped | |
1058 | * in multiples of the page size. For a file that is not a multiple of | |
1059 | * the page size, the remaining memory is zeroed when mapped, and | |
1060 | * writes to that region are not written out to the file." | |
1061 | */ | |
a1c7c137 | 1062 | kaddr = kmap_atomic(page); |
09cbfeaf | 1063 | memset(kaddr + len, 0, PAGE_SIZE - len); |
1e51764a | 1064 | flush_dcache_page(page); |
a1c7c137 | 1065 | kunmap_atomic(kaddr); |
1e51764a AB |
1066 | |
1067 | if (i_size > synced_i_size) { | |
a9185b41 | 1068 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a AB |
1069 | if (err) |
1070 | goto out_unlock; | |
1071 | } | |
1072 | ||
1073 | return do_writepage(page, len); | |
1074 | ||
1075 | out_unlock: | |
1076 | unlock_page(page); | |
1077 | return err; | |
1078 | } | |
1079 | ||
1080 | /** | |
1081 | * do_attr_changes - change inode attributes. | |
1082 | * @inode: inode to change attributes for | |
1083 | * @attr: describes attributes to change | |
1084 | */ | |
1085 | static void do_attr_changes(struct inode *inode, const struct iattr *attr) | |
1086 | { | |
1087 | if (attr->ia_valid & ATTR_UID) | |
1088 | inode->i_uid = attr->ia_uid; | |
1089 | if (attr->ia_valid & ATTR_GID) | |
1090 | inode->i_gid = attr->ia_gid; | |
1091 | if (attr->ia_valid & ATTR_ATIME) | |
1092 | inode->i_atime = timespec_trunc(attr->ia_atime, | |
1093 | inode->i_sb->s_time_gran); | |
1094 | if (attr->ia_valid & ATTR_MTIME) | |
1095 | inode->i_mtime = timespec_trunc(attr->ia_mtime, | |
1096 | inode->i_sb->s_time_gran); | |
1097 | if (attr->ia_valid & ATTR_CTIME) | |
1098 | inode->i_ctime = timespec_trunc(attr->ia_ctime, | |
1099 | inode->i_sb->s_time_gran); | |
1100 | if (attr->ia_valid & ATTR_MODE) { | |
1101 | umode_t mode = attr->ia_mode; | |
1102 | ||
1103 | if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) | |
1104 | mode &= ~S_ISGID; | |
1105 | inode->i_mode = mode; | |
1106 | } | |
1107 | } | |
1108 | ||
1109 | /** | |
1110 | * do_truncation - truncate an inode. | |
1111 | * @c: UBIFS file-system description object | |
1112 | * @inode: inode to truncate | |
1113 | * @attr: inode attribute changes description | |
1114 | * | |
1115 | * This function implements VFS '->setattr()' call when the inode is truncated | |
1116 | * to a smaller size. Returns zero in case of success and a negative error code | |
1117 | * in case of failure. | |
1118 | */ | |
1119 | static int do_truncation(struct ubifs_info *c, struct inode *inode, | |
1120 | const struct iattr *attr) | |
1121 | { | |
1122 | int err; | |
1123 | struct ubifs_budget_req req; | |
1124 | loff_t old_size = inode->i_size, new_size = attr->ia_size; | |
04da11bf | 1125 | int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1; |
1e51764a AB |
1126 | struct ubifs_inode *ui = ubifs_inode(inode); |
1127 | ||
1128 | dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size); | |
1129 | memset(&req, 0, sizeof(struct ubifs_budget_req)); | |
1130 | ||
1131 | /* | |
1132 | * If this is truncation to a smaller size, and we do not truncate on a | |
1133 | * block boundary, budget for changing one data block, because the last | |
1134 | * block will be re-written. | |
1135 | */ | |
1136 | if (new_size & (UBIFS_BLOCK_SIZE - 1)) | |
1137 | req.dirtied_page = 1; | |
1138 | ||
1139 | req.dirtied_ino = 1; | |
1140 | /* A funny way to budget for truncation node */ | |
1141 | req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ; | |
1142 | err = ubifs_budget_space(c, &req); | |
04da11bf AB |
1143 | if (err) { |
1144 | /* | |
1145 | * Treat truncations to zero as deletion and always allow them, | |
1146 | * just like we do for '->unlink()'. | |
1147 | */ | |
1148 | if (new_size || err != -ENOSPC) | |
1149 | return err; | |
1150 | budgeted = 0; | |
1151 | } | |
1e51764a | 1152 | |
2c27c65e | 1153 | truncate_setsize(inode, new_size); |
1e51764a AB |
1154 | |
1155 | if (offset) { | |
09cbfeaf | 1156 | pgoff_t index = new_size >> PAGE_SHIFT; |
1e51764a AB |
1157 | struct page *page; |
1158 | ||
1159 | page = find_lock_page(inode->i_mapping, index); | |
1160 | if (page) { | |
1161 | if (PageDirty(page)) { | |
1162 | /* | |
1163 | * 'ubifs_jnl_truncate()' will try to truncate | |
1164 | * the last data node, but it contains | |
1165 | * out-of-date data because the page is dirty. | |
1166 | * Write the page now, so that | |
1167 | * 'ubifs_jnl_truncate()' will see an already | |
1168 | * truncated (and up to date) data node. | |
1169 | */ | |
1170 | ubifs_assert(PagePrivate(page)); | |
1171 | ||
1172 | clear_page_dirty_for_io(page); | |
1173 | if (UBIFS_BLOCKS_PER_PAGE_SHIFT) | |
1174 | offset = new_size & | |
09cbfeaf | 1175 | (PAGE_SIZE - 1); |
1e51764a | 1176 | err = do_writepage(page, offset); |
09cbfeaf | 1177 | put_page(page); |
1e51764a AB |
1178 | if (err) |
1179 | goto out_budg; | |
1180 | /* | |
1181 | * We could now tell 'ubifs_jnl_truncate()' not | |
1182 | * to read the last block. | |
1183 | */ | |
1184 | } else { | |
1185 | /* | |
1186 | * We could 'kmap()' the page and pass the data | |
1187 | * to 'ubifs_jnl_truncate()' to save it from | |
1188 | * having to read it. | |
1189 | */ | |
1190 | unlock_page(page); | |
09cbfeaf | 1191 | put_page(page); |
1e51764a AB |
1192 | } |
1193 | } | |
1194 | } | |
1195 | ||
1196 | mutex_lock(&ui->ui_mutex); | |
1197 | ui->ui_size = inode->i_size; | |
1198 | /* Truncation changes inode [mc]time */ | |
1199 | inode->i_mtime = inode->i_ctime = ubifs_current_time(inode); | |
873a64c7 | 1200 | /* Other attributes may be changed at the same time as well */ |
1e51764a | 1201 | do_attr_changes(inode, attr); |
1e51764a AB |
1202 | err = ubifs_jnl_truncate(c, inode, old_size, new_size); |
1203 | mutex_unlock(&ui->ui_mutex); | |
873a64c7 | 1204 | |
1e51764a | 1205 | out_budg: |
04da11bf AB |
1206 | if (budgeted) |
1207 | ubifs_release_budget(c, &req); | |
1208 | else { | |
b137545c | 1209 | c->bi.nospace = c->bi.nospace_rp = 0; |
04da11bf AB |
1210 | smp_wmb(); |
1211 | } | |
1e51764a AB |
1212 | return err; |
1213 | } | |
1214 | ||
1215 | /** | |
1216 | * do_setattr - change inode attributes. | |
1217 | * @c: UBIFS file-system description object | |
1218 | * @inode: inode to change attributes for | |
1219 | * @attr: inode attribute changes description | |
1220 | * | |
1221 | * This function implements VFS '->setattr()' call for all cases except | |
1222 | * truncations to smaller size. Returns zero in case of success and a negative | |
1223 | * error code in case of failure. | |
1224 | */ | |
1225 | static int do_setattr(struct ubifs_info *c, struct inode *inode, | |
1226 | const struct iattr *attr) | |
1227 | { | |
1228 | int err, release; | |
1229 | loff_t new_size = attr->ia_size; | |
1230 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1231 | struct ubifs_budget_req req = { .dirtied_ino = 1, | |
dab4b4d2 | 1232 | .dirtied_ino_d = ALIGN(ui->data_len, 8) }; |
1e51764a AB |
1233 | |
1234 | err = ubifs_budget_space(c, &req); | |
1235 | if (err) | |
1236 | return err; | |
1237 | ||
1238 | if (attr->ia_valid & ATTR_SIZE) { | |
1239 | dbg_gen("size %lld -> %lld", inode->i_size, new_size); | |
2c27c65e | 1240 | truncate_setsize(inode, new_size); |
1e51764a AB |
1241 | } |
1242 | ||
1243 | mutex_lock(&ui->ui_mutex); | |
1244 | if (attr->ia_valid & ATTR_SIZE) { | |
1245 | /* Truncation changes inode [mc]time */ | |
1246 | inode->i_mtime = inode->i_ctime = ubifs_current_time(inode); | |
2c27c65e | 1247 | /* 'truncate_setsize()' changed @i_size, update @ui_size */ |
1e51764a AB |
1248 | ui->ui_size = inode->i_size; |
1249 | } | |
1250 | ||
1251 | do_attr_changes(inode, attr); | |
1252 | ||
1253 | release = ui->dirty; | |
1254 | if (attr->ia_valid & ATTR_SIZE) | |
1255 | /* | |
1256 | * Inode length changed, so we have to make sure | |
1257 | * @I_DIRTY_DATASYNC is set. | |
1258 | */ | |
1259 | __mark_inode_dirty(inode, I_DIRTY_SYNC | I_DIRTY_DATASYNC); | |
1260 | else | |
1261 | mark_inode_dirty_sync(inode); | |
1262 | mutex_unlock(&ui->ui_mutex); | |
1263 | ||
1264 | if (release) | |
1265 | ubifs_release_budget(c, &req); | |
1266 | if (IS_SYNC(inode)) | |
a9185b41 | 1267 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a | 1268 | return err; |
1e51764a AB |
1269 | } |
1270 | ||
1271 | int ubifs_setattr(struct dentry *dentry, struct iattr *attr) | |
1272 | { | |
1273 | int err; | |
2b0143b5 | 1274 | struct inode *inode = d_inode(dentry); |
1e51764a AB |
1275 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1276 | ||
7d32c2bb AB |
1277 | dbg_gen("ino %lu, mode %#x, ia_valid %#x", |
1278 | inode->i_ino, inode->i_mode, attr->ia_valid); | |
31051c85 | 1279 | err = setattr_prepare(dentry, attr); |
1e51764a AB |
1280 | if (err) |
1281 | return err; | |
1282 | ||
d808efb4 | 1283 | err = dbg_check_synced_i_size(c, inode); |
1e51764a AB |
1284 | if (err) |
1285 | return err; | |
1286 | ||
1287 | if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size < inode->i_size) | |
1288 | /* Truncation to a smaller size */ | |
1289 | err = do_truncation(c, inode, attr); | |
1290 | else | |
1291 | err = do_setattr(c, inode, attr); | |
1292 | ||
1293 | return err; | |
1294 | } | |
1295 | ||
d47992f8 LC |
1296 | static void ubifs_invalidatepage(struct page *page, unsigned int offset, |
1297 | unsigned int length) | |
1e51764a AB |
1298 | { |
1299 | struct inode *inode = page->mapping->host; | |
1300 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
1301 | ||
1302 | ubifs_assert(PagePrivate(page)); | |
09cbfeaf | 1303 | if (offset || length < PAGE_SIZE) |
1e51764a AB |
1304 | /* Partial page remains dirty */ |
1305 | return; | |
1306 | ||
1307 | if (PageChecked(page)) | |
1308 | release_new_page_budget(c); | |
1309 | else | |
1310 | release_existing_page_budget(c); | |
1311 | ||
1312 | atomic_long_dec(&c->dirty_pg_cnt); | |
1313 | ClearPagePrivate(page); | |
1314 | ClearPageChecked(page); | |
1315 | } | |
1316 | ||
02c24a82 | 1317 | int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
1e51764a | 1318 | { |
7ea80859 | 1319 | struct inode *inode = file->f_mapping->host; |
1e51764a AB |
1320 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1321 | int err; | |
1322 | ||
1323 | dbg_gen("syncing inode %lu", inode->i_ino); | |
1324 | ||
3b2f9a01 AB |
1325 | if (c->ro_mount) |
1326 | /* | |
1327 | * For some really strange reasons VFS does not filter out | |
1328 | * 'fsync()' for R/O mounted file-systems as per 2.6.39. | |
1329 | */ | |
78530bf7 AB |
1330 | return 0; |
1331 | ||
02c24a82 JB |
1332 | err = filemap_write_and_wait_range(inode->i_mapping, start, end); |
1333 | if (err) | |
1334 | return err; | |
5955102c | 1335 | inode_lock(inode); |
02c24a82 JB |
1336 | |
1337 | /* Synchronize the inode unless this is a 'datasync()' call. */ | |
1e51764a | 1338 | if (!datasync || (inode->i_state & I_DIRTY_DATASYNC)) { |
a9185b41 | 1339 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a | 1340 | if (err) |
02c24a82 | 1341 | goto out; |
1e51764a AB |
1342 | } |
1343 | ||
1344 | /* | |
1345 | * Nodes related to this inode may still sit in a write-buffer. Flush | |
1346 | * them. | |
1347 | */ | |
1348 | err = ubifs_sync_wbufs_by_inode(c, inode); | |
02c24a82 | 1349 | out: |
5955102c | 1350 | inode_unlock(inode); |
02c24a82 | 1351 | return err; |
1e51764a AB |
1352 | } |
1353 | ||
1354 | /** | |
1355 | * mctime_update_needed - check if mtime or ctime update is needed. | |
1356 | * @inode: the inode to do the check for | |
1357 | * @now: current time | |
1358 | * | |
1359 | * This helper function checks if the inode mtime/ctime should be updated or | |
1360 | * not. If current values of the time-stamps are within the UBIFS inode time | |
1361 | * granularity, they are not updated. This is an optimization. | |
1362 | */ | |
1363 | static inline int mctime_update_needed(const struct inode *inode, | |
1364 | const struct timespec *now) | |
1365 | { | |
1366 | if (!timespec_equal(&inode->i_mtime, now) || | |
1367 | !timespec_equal(&inode->i_ctime, now)) | |
1368 | return 1; | |
1369 | return 0; | |
1370 | } | |
1371 | ||
8c1c5f26 DY |
1372 | #ifdef CONFIG_UBIFS_ATIME_SUPPORT |
1373 | /** | |
1374 | * ubifs_update_time - update time of inode. | |
1375 | * @inode: inode to update | |
1376 | * | |
1377 | * This function updates time of the inode. | |
1378 | */ | |
1379 | int ubifs_update_time(struct inode *inode, struct timespec *time, | |
1380 | int flags) | |
1381 | { | |
1382 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1383 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
1384 | struct ubifs_budget_req req = { .dirtied_ino = 1, | |
1385 | .dirtied_ino_d = ALIGN(ui->data_len, 8) }; | |
1386 | int iflags = I_DIRTY_TIME; | |
1387 | int err, release; | |
1388 | ||
1389 | err = ubifs_budget_space(c, &req); | |
1390 | if (err) | |
1391 | return err; | |
1392 | ||
1393 | mutex_lock(&ui->ui_mutex); | |
1394 | if (flags & S_ATIME) | |
1395 | inode->i_atime = *time; | |
1396 | if (flags & S_CTIME) | |
1397 | inode->i_ctime = *time; | |
1398 | if (flags & S_MTIME) | |
1399 | inode->i_mtime = *time; | |
1400 | ||
1401 | if (!(inode->i_sb->s_flags & MS_LAZYTIME)) | |
1402 | iflags |= I_DIRTY_SYNC; | |
1403 | ||
1404 | release = ui->dirty; | |
1405 | __mark_inode_dirty(inode, iflags); | |
1406 | mutex_unlock(&ui->ui_mutex); | |
1407 | if (release) | |
1408 | ubifs_release_budget(c, &req); | |
1409 | return 0; | |
1410 | } | |
1411 | #endif | |
1412 | ||
1e51764a | 1413 | /** |
ec037dfc | 1414 | * update_mctime - update mtime and ctime of an inode. |
1e51764a AB |
1415 | * @inode: inode to update |
1416 | * | |
1417 | * This function updates mtime and ctime of the inode if it is not equivalent to | |
1418 | * current time. Returns zero in case of success and a negative error code in | |
1419 | * case of failure. | |
1420 | */ | |
f5674c31 | 1421 | static int update_mctime(struct inode *inode) |
1e51764a AB |
1422 | { |
1423 | struct timespec now = ubifs_current_time(inode); | |
1424 | struct ubifs_inode *ui = ubifs_inode(inode); | |
f5674c31 | 1425 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1e51764a AB |
1426 | |
1427 | if (mctime_update_needed(inode, &now)) { | |
1428 | int err, release; | |
1429 | struct ubifs_budget_req req = { .dirtied_ino = 1, | |
dab4b4d2 | 1430 | .dirtied_ino_d = ALIGN(ui->data_len, 8) }; |
1e51764a AB |
1431 | |
1432 | err = ubifs_budget_space(c, &req); | |
1433 | if (err) | |
1434 | return err; | |
1435 | ||
1436 | mutex_lock(&ui->ui_mutex); | |
1437 | inode->i_mtime = inode->i_ctime = ubifs_current_time(inode); | |
1438 | release = ui->dirty; | |
1439 | mark_inode_dirty_sync(inode); | |
1440 | mutex_unlock(&ui->ui_mutex); | |
1441 | if (release) | |
1442 | ubifs_release_budget(c, &req); | |
1443 | } | |
1444 | ||
1445 | return 0; | |
1446 | } | |
1447 | ||
f5674c31 | 1448 | static ssize_t ubifs_write_iter(struct kiocb *iocb, struct iov_iter *from) |
1e51764a | 1449 | { |
f5674c31 | 1450 | int err = update_mctime(file_inode(iocb->ki_filp)); |
1e51764a AB |
1451 | if (err) |
1452 | return err; | |
1453 | ||
f5674c31 | 1454 | return generic_file_write_iter(iocb, from); |
1e51764a AB |
1455 | } |
1456 | ||
1457 | static int ubifs_set_page_dirty(struct page *page) | |
1458 | { | |
1459 | int ret; | |
1460 | ||
1461 | ret = __set_page_dirty_nobuffers(page); | |
1462 | /* | |
1463 | * An attempt to dirty a page without budgeting for it - should not | |
1464 | * happen. | |
1465 | */ | |
1466 | ubifs_assert(ret == 0); | |
1467 | return ret; | |
1468 | } | |
1469 | ||
4ac1c17b KS |
1470 | #ifdef CONFIG_MIGRATION |
1471 | static int ubifs_migrate_page(struct address_space *mapping, | |
1472 | struct page *newpage, struct page *page, enum migrate_mode mode) | |
1473 | { | |
1474 | int rc; | |
1475 | ||
1476 | rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0); | |
1477 | if (rc != MIGRATEPAGE_SUCCESS) | |
1478 | return rc; | |
1479 | ||
1480 | if (PagePrivate(page)) { | |
1481 | ClearPagePrivate(page); | |
1482 | SetPagePrivate(newpage); | |
1483 | } | |
1484 | ||
1485 | migrate_page_copy(newpage, page); | |
1486 | return MIGRATEPAGE_SUCCESS; | |
1487 | } | |
1488 | #endif | |
1489 | ||
1e51764a AB |
1490 | static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags) |
1491 | { | |
1492 | /* | |
1493 | * An attempt to release a dirty page without budgeting for it - should | |
1494 | * not happen. | |
1495 | */ | |
1496 | if (PageWriteback(page)) | |
1497 | return 0; | |
1498 | ubifs_assert(PagePrivate(page)); | |
1499 | ubifs_assert(0); | |
1500 | ClearPagePrivate(page); | |
1501 | ClearPageChecked(page); | |
1502 | return 1; | |
1503 | } | |
1504 | ||
1505 | /* | |
c4361570 AB |
1506 | * mmap()d file has taken write protection fault and is being made writable. |
1507 | * UBIFS must ensure page is budgeted for. | |
1e51764a | 1508 | */ |
11bac800 | 1509 | static int ubifs_vm_page_mkwrite(struct vm_fault *vmf) |
1e51764a | 1510 | { |
c2ec175c | 1511 | struct page *page = vmf->page; |
11bac800 | 1512 | struct inode *inode = file_inode(vmf->vma->vm_file); |
1e51764a AB |
1513 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1514 | struct timespec now = ubifs_current_time(inode); | |
1515 | struct ubifs_budget_req req = { .new_page = 1 }; | |
1516 | int err, update_time; | |
1517 | ||
1518 | dbg_gen("ino %lu, pg %lu, i_size %lld", inode->i_ino, page->index, | |
1519 | i_size_read(inode)); | |
2ef13294 | 1520 | ubifs_assert(!c->ro_media && !c->ro_mount); |
1e51764a | 1521 | |
2680d722 | 1522 | if (unlikely(c->ro_error)) |
c2ec175c | 1523 | return VM_FAULT_SIGBUS; /* -EROFS */ |
1e51764a AB |
1524 | |
1525 | /* | |
1526 | * We have not locked @page so far so we may budget for changing the | |
1527 | * page. Note, we cannot do this after we locked the page, because | |
1528 | * budgeting may cause write-back which would cause deadlock. | |
1529 | * | |
1530 | * At the moment we do not know whether the page is dirty or not, so we | |
1531 | * assume that it is not and budget for a new page. We could look at | |
1532 | * the @PG_private flag and figure this out, but we may race with write | |
1533 | * back and the page state may change by the time we lock it, so this | |
1534 | * would need additional care. We do not bother with this at the | |
1535 | * moment, although it might be good idea to do. Instead, we allocate | |
1536 | * budget for a new page and amend it later on if the page was in fact | |
1537 | * dirty. | |
1538 | * | |
1539 | * The budgeting-related logic of this function is similar to what we | |
1540 | * do in 'ubifs_write_begin()' and 'ubifs_write_end()'. Glance there | |
1541 | * for more comments. | |
1542 | */ | |
1543 | update_time = mctime_update_needed(inode, &now); | |
1544 | if (update_time) | |
1545 | /* | |
1546 | * We have to change inode time stamp which requires extra | |
1547 | * budgeting. | |
1548 | */ | |
1549 | req.dirtied_ino = 1; | |
1550 | ||
1551 | err = ubifs_budget_space(c, &req); | |
1552 | if (unlikely(err)) { | |
1553 | if (err == -ENOSPC) | |
235c362b | 1554 | ubifs_warn(c, "out of space for mmapped file (inode number %lu)", |
79fda517 | 1555 | inode->i_ino); |
c2ec175c | 1556 | return VM_FAULT_SIGBUS; |
1e51764a AB |
1557 | } |
1558 | ||
1559 | lock_page(page); | |
1560 | if (unlikely(page->mapping != inode->i_mapping || | |
1561 | page_offset(page) > i_size_read(inode))) { | |
1562 | /* Page got truncated out from underneath us */ | |
1563 | err = -EINVAL; | |
1564 | goto out_unlock; | |
1565 | } | |
1566 | ||
1567 | if (PagePrivate(page)) | |
1568 | release_new_page_budget(c); | |
1569 | else { | |
1570 | if (!PageChecked(page)) | |
1571 | ubifs_convert_page_budget(c); | |
1572 | SetPagePrivate(page); | |
1573 | atomic_long_inc(&c->dirty_pg_cnt); | |
1574 | __set_page_dirty_nobuffers(page); | |
1575 | } | |
1576 | ||
1577 | if (update_time) { | |
1578 | int release; | |
1579 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1580 | ||
1581 | mutex_lock(&ui->ui_mutex); | |
1582 | inode->i_mtime = inode->i_ctime = ubifs_current_time(inode); | |
1583 | release = ui->dirty; | |
1584 | mark_inode_dirty_sync(inode); | |
1585 | mutex_unlock(&ui->ui_mutex); | |
1586 | if (release) | |
1587 | ubifs_release_dirty_inode_budget(c, ui); | |
1588 | } | |
1589 | ||
182dcfd6 | 1590 | wait_for_stable_page(page); |
691a7c6f | 1591 | return VM_FAULT_LOCKED; |
1e51764a AB |
1592 | |
1593 | out_unlock: | |
1594 | unlock_page(page); | |
1595 | ubifs_release_budget(c, &req); | |
c2ec175c NP |
1596 | if (err) |
1597 | err = VM_FAULT_SIGBUS; | |
1e51764a AB |
1598 | return err; |
1599 | } | |
1600 | ||
f0f37e2f | 1601 | static const struct vm_operations_struct ubifs_file_vm_ops = { |
1e51764a | 1602 | .fault = filemap_fault, |
f1820361 | 1603 | .map_pages = filemap_map_pages, |
1e51764a AB |
1604 | .page_mkwrite = ubifs_vm_page_mkwrite, |
1605 | }; | |
1606 | ||
1607 | static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma) | |
1608 | { | |
1609 | int err; | |
959c2de2 RW |
1610 | struct inode *inode = file->f_mapping->host; |
1611 | ||
1612 | if (ubifs_crypt_is_encrypted(inode)) { | |
1613 | err = fscrypt_get_encryption_info(inode); | |
1614 | if (err) | |
1615 | return -EACCES; | |
1616 | if (!fscrypt_has_encryption_key(inode)) | |
1617 | return -ENOKEY; | |
1618 | } | |
1e51764a | 1619 | |
1e51764a AB |
1620 | err = generic_file_mmap(file, vma); |
1621 | if (err) | |
1622 | return err; | |
1623 | vma->vm_ops = &ubifs_file_vm_ops; | |
8c1c5f26 DY |
1624 | #ifdef CONFIG_UBIFS_ATIME_SUPPORT |
1625 | file_accessed(file); | |
1626 | #endif | |
1e51764a AB |
1627 | return 0; |
1628 | } | |
1629 | ||
a79bff21 RW |
1630 | static int ubifs_file_open(struct inode *inode, struct file *filp) |
1631 | { | |
1632 | int ret; | |
1633 | struct dentry *dir; | |
1634 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
1635 | ||
1636 | if (ubifs_crypt_is_encrypted(inode)) { | |
1637 | ret = fscrypt_get_encryption_info(inode); | |
1638 | if (ret) | |
1639 | return -EACCES; | |
1640 | if (!fscrypt_has_encryption_key(inode)) | |
1641 | return -ENOKEY; | |
1642 | } | |
1643 | ||
1644 | dir = dget_parent(file_dentry(filp)); | |
1645 | if (ubifs_crypt_is_encrypted(d_inode(dir)) && | |
1646 | !fscrypt_has_permitted_context(d_inode(dir), inode)) { | |
1647 | ubifs_err(c, "Inconsistent encryption contexts: %lu/%lu", | |
1648 | (unsigned long) d_inode(dir)->i_ino, | |
1649 | (unsigned long) inode->i_ino); | |
1650 | dput(dir); | |
1651 | ubifs_ro_mode(c, -EPERM); | |
1652 | return -EPERM; | |
1653 | } | |
1654 | dput(dir); | |
1655 | ||
1656 | return 0; | |
1657 | } | |
1658 | ||
ca7f85be RW |
1659 | static const char *ubifs_get_link(struct dentry *dentry, |
1660 | struct inode *inode, | |
1661 | struct delayed_call *done) | |
1662 | { | |
1663 | int err; | |
1664 | struct fscrypt_symlink_data *sd; | |
1665 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1666 | struct fscrypt_str cstr; | |
1667 | struct fscrypt_str pstr; | |
1668 | ||
1669 | if (!ubifs_crypt_is_encrypted(inode)) | |
1670 | return ui->data; | |
1671 | ||
1672 | if (!dentry) | |
1673 | return ERR_PTR(-ECHILD); | |
1674 | ||
1675 | err = fscrypt_get_encryption_info(inode); | |
1676 | if (err) | |
1677 | return ERR_PTR(err); | |
1678 | ||
1679 | sd = (struct fscrypt_symlink_data *)ui->data; | |
1680 | cstr.name = sd->encrypted_path; | |
1681 | cstr.len = le16_to_cpu(sd->len); | |
1682 | ||
1683 | if (cstr.len == 0) | |
1684 | return ERR_PTR(-ENOENT); | |
1685 | ||
1686 | if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > ui->data_len) | |
1687 | return ERR_PTR(-EIO); | |
1688 | ||
1689 | err = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr); | |
1690 | if (err) | |
1691 | return ERR_PTR(err); | |
1692 | ||
1693 | err = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr); | |
1694 | if (err) { | |
1695 | fscrypt_fname_free_buffer(&pstr); | |
1696 | return ERR_PTR(err); | |
1697 | } | |
1698 | ||
1699 | pstr.name[pstr.len] = '\0'; | |
1700 | ||
1701 | // XXX this probably won't happen anymore... | |
1702 | if (pstr.name[0] == '\0') { | |
1703 | fscrypt_fname_free_buffer(&pstr); | |
1704 | return ERR_PTR(-ENOENT); | |
1705 | } | |
1706 | ||
1707 | set_delayed_call(done, kfree_link, pstr.name); | |
1708 | return pstr.name; | |
1709 | } | |
1710 | ||
1711 | ||
e8b81566 | 1712 | const struct address_space_operations ubifs_file_address_operations = { |
1e51764a AB |
1713 | .readpage = ubifs_readpage, |
1714 | .writepage = ubifs_writepage, | |
1715 | .write_begin = ubifs_write_begin, | |
1716 | .write_end = ubifs_write_end, | |
1717 | .invalidatepage = ubifs_invalidatepage, | |
1718 | .set_page_dirty = ubifs_set_page_dirty, | |
4ac1c17b KS |
1719 | #ifdef CONFIG_MIGRATION |
1720 | .migratepage = ubifs_migrate_page, | |
1721 | #endif | |
1e51764a AB |
1722 | .releasepage = ubifs_releasepage, |
1723 | }; | |
1724 | ||
e8b81566 | 1725 | const struct inode_operations ubifs_file_inode_operations = { |
1e51764a AB |
1726 | .setattr = ubifs_setattr, |
1727 | .getattr = ubifs_getattr, | |
1e51764a | 1728 | .listxattr = ubifs_listxattr, |
8c1c5f26 DY |
1729 | #ifdef CONFIG_UBIFS_ATIME_SUPPORT |
1730 | .update_time = ubifs_update_time, | |
1731 | #endif | |
1e51764a AB |
1732 | }; |
1733 | ||
e8b81566 | 1734 | const struct inode_operations ubifs_symlink_inode_operations = { |
ca7f85be | 1735 | .get_link = ubifs_get_link, |
1e51764a AB |
1736 | .setattr = ubifs_setattr, |
1737 | .getattr = ubifs_getattr, | |
895d9db2 | 1738 | .listxattr = ubifs_listxattr, |
8c1c5f26 DY |
1739 | #ifdef CONFIG_UBIFS_ATIME_SUPPORT |
1740 | .update_time = ubifs_update_time, | |
1741 | #endif | |
1e51764a AB |
1742 | }; |
1743 | ||
e8b81566 | 1744 | const struct file_operations ubifs_file_operations = { |
1e51764a | 1745 | .llseek = generic_file_llseek, |
aad4f8bb | 1746 | .read_iter = generic_file_read_iter, |
f5674c31 | 1747 | .write_iter = ubifs_write_iter, |
1e51764a AB |
1748 | .mmap = ubifs_file_mmap, |
1749 | .fsync = ubifs_fsync, | |
1750 | .unlocked_ioctl = ubifs_ioctl, | |
1751 | .splice_read = generic_file_splice_read, | |
8d020765 | 1752 | .splice_write = iter_file_splice_write, |
a79bff21 | 1753 | .open = ubifs_file_open, |
1e51764a AB |
1754 | #ifdef CONFIG_COMPAT |
1755 | .compat_ioctl = ubifs_compat_ioctl, | |
1756 | #endif | |
1757 | }; |