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2b27bdcc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1e51764a AB |
2 | /* |
3 | * This file is part of UBIFS. | |
4 | * | |
5 | * Copyright (C) 2006-2008 Nokia Corporation. | |
6 | * | |
1e51764a AB |
7 | * Authors: Artem Bityutskiy (Битюцкий Артём) |
8 | * Adrian Hunter | |
9 | */ | |
10 | ||
11 | /* | |
873a64c7 | 12 | * This file implements VFS file and inode operations for regular files, device |
1e51764a AB |
13 | * nodes and symlinks as well as address space operations. |
14 | * | |
873a64c7 AB |
15 | * UBIFS uses 2 page flags: @PG_private and @PG_checked. @PG_private is set if |
16 | * the page is dirty and is used for optimization purposes - dirty pages are | |
17 | * not budgeted so the flag shows that 'ubifs_write_end()' should not release | |
18 | * the budget for this page. The @PG_checked flag is set if full budgeting is | |
19 | * required for the page e.g., when it corresponds to a file hole or it is | |
20 | * beyond the file size. The budgeting is done in 'ubifs_write_begin()', because | |
21 | * it is OK to fail in this function, and the budget is released in | |
22 | * 'ubifs_write_end()'. So the @PG_private and @PG_checked flags carry | |
23 | * information about how the page was budgeted, to make it possible to release | |
24 | * the budget properly. | |
1e51764a | 25 | * |
873a64c7 AB |
26 | * A thing to keep in mind: inode @i_mutex is locked in most VFS operations we |
27 | * implement. However, this is not true for 'ubifs_writepage()', which may be | |
5c57f20b AB |
28 | * called with @i_mutex unlocked. For example, when flusher thread is doing |
29 | * background write-back, it calls 'ubifs_writepage()' with unlocked @i_mutex. | |
30 | * At "normal" work-paths the @i_mutex is locked in 'ubifs_writepage()', e.g. | |
31 | * in the "sys_write -> alloc_pages -> direct reclaim path". So, in | |
32 | * 'ubifs_writepage()' we are only guaranteed that the page is locked. | |
1e51764a | 33 | * |
873a64c7 AB |
34 | * Similarly, @i_mutex is not always locked in 'ubifs_readpage()', e.g., the |
35 | * read-ahead path does not lock it ("sys_read -> generic_file_aio_read -> | |
eaff8079 | 36 | * ondemand_readahead -> readpage"). In case of readahead, @I_SYNC flag is not |
873a64c7 | 37 | * set as well. However, UBIFS disables readahead. |
1e51764a AB |
38 | */ |
39 | ||
40 | #include "ubifs.h" | |
41 | #include <linux/mount.h> | |
5a0e3ad6 | 42 | #include <linux/slab.h> |
4ac1c17b | 43 | #include <linux/migrate.h> |
1e51764a AB |
44 | |
45 | static int read_block(struct inode *inode, void *addr, unsigned int block, | |
46 | struct ubifs_data_node *dn) | |
47 | { | |
48 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
49 | int err, len, out_len; | |
50 | union ubifs_key key; | |
51 | unsigned int dlen; | |
52 | ||
53 | data_key_init(c, &key, inode->i_ino, block); | |
54 | err = ubifs_tnc_lookup(c, &key, dn); | |
55 | if (err) { | |
56 | if (err == -ENOENT) | |
57 | /* Not found, so it must be a hole */ | |
58 | memset(addr, 0, UBIFS_BLOCK_SIZE); | |
59 | return err; | |
60 | } | |
61 | ||
6eb61d58 | 62 | ubifs_assert(c, le64_to_cpu(dn->ch.sqnum) > |
f92b9826 | 63 | ubifs_inode(inode)->creat_sqnum); |
1e51764a AB |
64 | len = le32_to_cpu(dn->size); |
65 | if (len <= 0 || len > UBIFS_BLOCK_SIZE) | |
66 | goto dump; | |
67 | ||
68 | dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; | |
7799953b RW |
69 | |
70 | if (ubifs_crypt_is_encrypted(inode)) { | |
71 | err = ubifs_decrypt(inode, dn, &dlen, block); | |
72 | if (err) | |
73 | goto dump; | |
74 | } | |
75 | ||
1e51764a | 76 | out_len = UBIFS_BLOCK_SIZE; |
235c362b | 77 | err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len, |
1e51764a AB |
78 | le16_to_cpu(dn->compr_type)); |
79 | if (err || len != out_len) | |
80 | goto dump; | |
81 | ||
82 | /* | |
83 | * Data length can be less than a full block, even for blocks that are | |
84 | * not the last in the file (e.g., as a result of making a hole and | |
85 | * appending data). Ensure that the remainder is zeroed out. | |
86 | */ | |
87 | if (len < UBIFS_BLOCK_SIZE) | |
88 | memset(addr + len, 0, UBIFS_BLOCK_SIZE - len); | |
89 | ||
90 | return 0; | |
91 | ||
92 | dump: | |
235c362b | 93 | ubifs_err(c, "bad data node (block %u, inode %lu)", |
1e51764a | 94 | block, inode->i_ino); |
edf6be24 | 95 | ubifs_dump_node(c, dn); |
1e51764a AB |
96 | return -EINVAL; |
97 | } | |
98 | ||
99 | static int do_readpage(struct page *page) | |
100 | { | |
101 | void *addr; | |
102 | int err = 0, i; | |
103 | unsigned int block, beyond; | |
104 | struct ubifs_data_node *dn; | |
105 | struct inode *inode = page->mapping->host; | |
6eb61d58 | 106 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1e51764a AB |
107 | loff_t i_size = i_size_read(inode); |
108 | ||
109 | dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx", | |
110 | inode->i_ino, page->index, i_size, page->flags); | |
6eb61d58 RW |
111 | ubifs_assert(c, !PageChecked(page)); |
112 | ubifs_assert(c, !PagePrivate(page)); | |
1e51764a AB |
113 | |
114 | addr = kmap(page); | |
115 | ||
116 | block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
117 | beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT; | |
118 | if (block >= beyond) { | |
119 | /* Reading beyond inode */ | |
120 | SetPageChecked(page); | |
09cbfeaf | 121 | memset(addr, 0, PAGE_SIZE); |
1e51764a AB |
122 | goto out; |
123 | } | |
124 | ||
125 | dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS); | |
126 | if (!dn) { | |
127 | err = -ENOMEM; | |
128 | goto error; | |
129 | } | |
130 | ||
131 | i = 0; | |
132 | while (1) { | |
133 | int ret; | |
134 | ||
135 | if (block >= beyond) { | |
136 | /* Reading beyond inode */ | |
137 | err = -ENOENT; | |
138 | memset(addr, 0, UBIFS_BLOCK_SIZE); | |
139 | } else { | |
140 | ret = read_block(inode, addr, block, dn); | |
141 | if (ret) { | |
142 | err = ret; | |
143 | if (err != -ENOENT) | |
144 | break; | |
ed382d58 AH |
145 | } else if (block + 1 == beyond) { |
146 | int dlen = le32_to_cpu(dn->size); | |
147 | int ilen = i_size & (UBIFS_BLOCK_SIZE - 1); | |
148 | ||
149 | if (ilen && ilen < dlen) | |
150 | memset(addr + ilen, 0, dlen - ilen); | |
1e51764a AB |
151 | } |
152 | } | |
153 | if (++i >= UBIFS_BLOCKS_PER_PAGE) | |
154 | break; | |
155 | block += 1; | |
156 | addr += UBIFS_BLOCK_SIZE; | |
157 | } | |
158 | if (err) { | |
235c362b | 159 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1e51764a AB |
160 | if (err == -ENOENT) { |
161 | /* Not found, so it must be a hole */ | |
162 | SetPageChecked(page); | |
163 | dbg_gen("hole"); | |
164 | goto out_free; | |
165 | } | |
235c362b | 166 | ubifs_err(c, "cannot read page %lu of inode %lu, error %d", |
1e51764a AB |
167 | page->index, inode->i_ino, err); |
168 | goto error; | |
169 | } | |
170 | ||
171 | out_free: | |
172 | kfree(dn); | |
173 | out: | |
174 | SetPageUptodate(page); | |
175 | ClearPageError(page); | |
176 | flush_dcache_page(page); | |
177 | kunmap(page); | |
178 | return 0; | |
179 | ||
180 | error: | |
181 | kfree(dn); | |
182 | ClearPageUptodate(page); | |
183 | SetPageError(page); | |
184 | flush_dcache_page(page); | |
185 | kunmap(page); | |
186 | return err; | |
187 | } | |
188 | ||
189 | /** | |
190 | * release_new_page_budget - release budget of a new page. | |
191 | * @c: UBIFS file-system description object | |
192 | * | |
193 | * This is a helper function which releases budget corresponding to the budget | |
194 | * of one new page of data. | |
195 | */ | |
196 | static void release_new_page_budget(struct ubifs_info *c) | |
197 | { | |
198 | struct ubifs_budget_req req = { .recalculate = 1, .new_page = 1 }; | |
199 | ||
200 | ubifs_release_budget(c, &req); | |
201 | } | |
202 | ||
203 | /** | |
204 | * release_existing_page_budget - release budget of an existing page. | |
205 | * @c: UBIFS file-system description object | |
206 | * | |
207 | * This is a helper function which releases budget corresponding to the budget | |
208 | * of changing one one page of data which already exists on the flash media. | |
209 | */ | |
210 | static void release_existing_page_budget(struct ubifs_info *c) | |
211 | { | |
b137545c | 212 | struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget}; |
1e51764a AB |
213 | |
214 | ubifs_release_budget(c, &req); | |
215 | } | |
216 | ||
217 | static int write_begin_slow(struct address_space *mapping, | |
54566b2c NP |
218 | loff_t pos, unsigned len, struct page **pagep, |
219 | unsigned flags) | |
1e51764a AB |
220 | { |
221 | struct inode *inode = mapping->host; | |
222 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
09cbfeaf | 223 | pgoff_t index = pos >> PAGE_SHIFT; |
1e51764a AB |
224 | struct ubifs_budget_req req = { .new_page = 1 }; |
225 | int uninitialized_var(err), appending = !!(pos + len > inode->i_size); | |
226 | struct page *page; | |
227 | ||
228 | dbg_gen("ino %lu, pos %llu, len %u, i_size %lld", | |
229 | inode->i_ino, pos, len, inode->i_size); | |
230 | ||
231 | /* | |
232 | * At the slow path we have to budget before locking the page, because | |
233 | * budgeting may force write-back, which would wait on locked pages and | |
234 | * deadlock if we had the page locked. At this point we do not know | |
235 | * anything about the page, so assume that this is a new page which is | |
236 | * written to a hole. This corresponds to largest budget. Later the | |
237 | * budget will be amended if this is not true. | |
238 | */ | |
239 | if (appending) | |
240 | /* We are appending data, budget for inode change */ | |
241 | req.dirtied_ino = 1; | |
242 | ||
243 | err = ubifs_budget_space(c, &req); | |
244 | if (unlikely(err)) | |
245 | return err; | |
246 | ||
54566b2c | 247 | page = grab_cache_page_write_begin(mapping, index, flags); |
1e51764a AB |
248 | if (unlikely(!page)) { |
249 | ubifs_release_budget(c, &req); | |
250 | return -ENOMEM; | |
251 | } | |
252 | ||
253 | if (!PageUptodate(page)) { | |
09cbfeaf | 254 | if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) |
1e51764a AB |
255 | SetPageChecked(page); |
256 | else { | |
257 | err = do_readpage(page); | |
258 | if (err) { | |
259 | unlock_page(page); | |
09cbfeaf | 260 | put_page(page); |
789c8993 | 261 | ubifs_release_budget(c, &req); |
1e51764a AB |
262 | return err; |
263 | } | |
264 | } | |
265 | ||
266 | SetPageUptodate(page); | |
267 | ClearPageError(page); | |
268 | } | |
269 | ||
270 | if (PagePrivate(page)) | |
271 | /* | |
272 | * The page is dirty, which means it was budgeted twice: | |
273 | * o first time the budget was allocated by the task which | |
274 | * made the page dirty and set the PG_private flag; | |
275 | * o and then we budgeted for it for the second time at the | |
276 | * very beginning of this function. | |
277 | * | |
278 | * So what we have to do is to release the page budget we | |
279 | * allocated. | |
280 | */ | |
281 | release_new_page_budget(c); | |
282 | else if (!PageChecked(page)) | |
283 | /* | |
284 | * We are changing a page which already exists on the media. | |
285 | * This means that changing the page does not make the amount | |
286 | * of indexing information larger, and this part of the budget | |
287 | * which we have already acquired may be released. | |
288 | */ | |
289 | ubifs_convert_page_budget(c); | |
290 | ||
291 | if (appending) { | |
292 | struct ubifs_inode *ui = ubifs_inode(inode); | |
293 | ||
294 | /* | |
295 | * 'ubifs_write_end()' is optimized from the fast-path part of | |
296 | * 'ubifs_write_begin()' and expects the @ui_mutex to be locked | |
297 | * if data is appended. | |
298 | */ | |
299 | mutex_lock(&ui->ui_mutex); | |
300 | if (ui->dirty) | |
301 | /* | |
302 | * The inode is dirty already, so we may free the | |
303 | * budget we allocated. | |
304 | */ | |
305 | ubifs_release_dirty_inode_budget(c, ui); | |
306 | } | |
307 | ||
308 | *pagep = page; | |
309 | return 0; | |
310 | } | |
311 | ||
312 | /** | |
313 | * allocate_budget - allocate budget for 'ubifs_write_begin()'. | |
314 | * @c: UBIFS file-system description object | |
315 | * @page: page to allocate budget for | |
316 | * @ui: UBIFS inode object the page belongs to | |
317 | * @appending: non-zero if the page is appended | |
318 | * | |
319 | * This is a helper function for 'ubifs_write_begin()' which allocates budget | |
320 | * for the operation. The budget is allocated differently depending on whether | |
321 | * this is appending, whether the page is dirty or not, and so on. This | |
322 | * function leaves the @ui->ui_mutex locked in case of appending. Returns zero | |
323 | * in case of success and %-ENOSPC in case of failure. | |
324 | */ | |
325 | static int allocate_budget(struct ubifs_info *c, struct page *page, | |
326 | struct ubifs_inode *ui, int appending) | |
327 | { | |
328 | struct ubifs_budget_req req = { .fast = 1 }; | |
329 | ||
330 | if (PagePrivate(page)) { | |
331 | if (!appending) | |
332 | /* | |
333 | * The page is dirty and we are not appending, which | |
334 | * means no budget is needed at all. | |
335 | */ | |
336 | return 0; | |
337 | ||
338 | mutex_lock(&ui->ui_mutex); | |
339 | if (ui->dirty) | |
340 | /* | |
341 | * The page is dirty and we are appending, so the inode | |
342 | * has to be marked as dirty. However, it is already | |
343 | * dirty, so we do not need any budget. We may return, | |
344 | * but @ui->ui_mutex hast to be left locked because we | |
345 | * should prevent write-back from flushing the inode | |
346 | * and freeing the budget. The lock will be released in | |
347 | * 'ubifs_write_end()'. | |
348 | */ | |
349 | return 0; | |
350 | ||
351 | /* | |
352 | * The page is dirty, we are appending, the inode is clean, so | |
353 | * we need to budget the inode change. | |
354 | */ | |
355 | req.dirtied_ino = 1; | |
356 | } else { | |
357 | if (PageChecked(page)) | |
358 | /* | |
359 | * The page corresponds to a hole and does not | |
360 | * exist on the media. So changing it makes | |
361 | * make the amount of indexing information | |
362 | * larger, and we have to budget for a new | |
363 | * page. | |
364 | */ | |
365 | req.new_page = 1; | |
366 | else | |
367 | /* | |
368 | * Not a hole, the change will not add any new | |
369 | * indexing information, budget for page | |
370 | * change. | |
371 | */ | |
372 | req.dirtied_page = 1; | |
373 | ||
374 | if (appending) { | |
375 | mutex_lock(&ui->ui_mutex); | |
376 | if (!ui->dirty) | |
377 | /* | |
378 | * The inode is clean but we will have to mark | |
379 | * it as dirty because we are appending. This | |
380 | * needs a budget. | |
381 | */ | |
382 | req.dirtied_ino = 1; | |
383 | } | |
384 | } | |
385 | ||
386 | return ubifs_budget_space(c, &req); | |
387 | } | |
388 | ||
389 | /* | |
390 | * This function is called when a page of data is going to be written. Since | |
391 | * the page of data will not necessarily go to the flash straight away, UBIFS | |
392 | * has to reserve space on the media for it, which is done by means of | |
393 | * budgeting. | |
394 | * | |
395 | * This is the hot-path of the file-system and we are trying to optimize it as | |
396 | * much as possible. For this reasons it is split on 2 parts - slow and fast. | |
397 | * | |
398 | * There many budgeting cases: | |
399 | * o a new page is appended - we have to budget for a new page and for | |
400 | * changing the inode; however, if the inode is already dirty, there is | |
401 | * no need to budget for it; | |
402 | * o an existing clean page is changed - we have budget for it; if the page | |
403 | * does not exist on the media (a hole), we have to budget for a new | |
404 | * page; otherwise, we may budget for changing an existing page; the | |
405 | * difference between these cases is that changing an existing page does | |
406 | * not introduce anything new to the FS indexing information, so it does | |
407 | * not grow, and smaller budget is acquired in this case; | |
408 | * o an existing dirty page is changed - no need to budget at all, because | |
409 | * the page budget has been acquired by earlier, when the page has been | |
410 | * marked dirty. | |
411 | * | |
412 | * UBIFS budgeting sub-system may force write-back if it thinks there is no | |
413 | * space to reserve. This imposes some locking restrictions and makes it | |
414 | * impossible to take into account the above cases, and makes it impossible to | |
415 | * optimize budgeting. | |
416 | * | |
417 | * The solution for this is that the fast path of 'ubifs_write_begin()' assumes | |
418 | * there is a plenty of flash space and the budget will be acquired quickly, | |
419 | * without forcing write-back. The slow path does not make this assumption. | |
420 | */ | |
421 | static int ubifs_write_begin(struct file *file, struct address_space *mapping, | |
422 | loff_t pos, unsigned len, unsigned flags, | |
423 | struct page **pagep, void **fsdata) | |
424 | { | |
425 | struct inode *inode = mapping->host; | |
426 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
427 | struct ubifs_inode *ui = ubifs_inode(inode); | |
09cbfeaf | 428 | pgoff_t index = pos >> PAGE_SHIFT; |
1e51764a | 429 | int uninitialized_var(err), appending = !!(pos + len > inode->i_size); |
f55aa591 | 430 | int skipped_read = 0; |
1e51764a AB |
431 | struct page *page; |
432 | ||
6eb61d58 RW |
433 | ubifs_assert(c, ubifs_inode(inode)->ui_size == inode->i_size); |
434 | ubifs_assert(c, !c->ro_media && !c->ro_mount); | |
1e51764a | 435 | |
2680d722 | 436 | if (unlikely(c->ro_error)) |
1e51764a AB |
437 | return -EROFS; |
438 | ||
439 | /* Try out the fast-path part first */ | |
54566b2c | 440 | page = grab_cache_page_write_begin(mapping, index, flags); |
1e51764a AB |
441 | if (unlikely(!page)) |
442 | return -ENOMEM; | |
443 | ||
444 | if (!PageUptodate(page)) { | |
445 | /* The page is not loaded from the flash */ | |
09cbfeaf | 446 | if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) { |
1e51764a AB |
447 | /* |
448 | * We change whole page so no need to load it. But we | |
6ed09c34 AB |
449 | * do not know whether this page exists on the media or |
450 | * not, so we assume the latter because it requires | |
451 | * larger budget. The assumption is that it is better | |
452 | * to budget a bit more than to read the page from the | |
453 | * media. Thus, we are setting the @PG_checked flag | |
454 | * here. | |
1e51764a AB |
455 | */ |
456 | SetPageChecked(page); | |
f55aa591 AH |
457 | skipped_read = 1; |
458 | } else { | |
1e51764a AB |
459 | err = do_readpage(page); |
460 | if (err) { | |
461 | unlock_page(page); | |
09cbfeaf | 462 | put_page(page); |
1e51764a AB |
463 | return err; |
464 | } | |
465 | } | |
466 | ||
467 | SetPageUptodate(page); | |
468 | ClearPageError(page); | |
469 | } | |
470 | ||
471 | err = allocate_budget(c, page, ui, appending); | |
472 | if (unlikely(err)) { | |
6eb61d58 | 473 | ubifs_assert(c, err == -ENOSPC); |
f55aa591 AH |
474 | /* |
475 | * If we skipped reading the page because we were going to | |
476 | * write all of it, then it is not up to date. | |
477 | */ | |
478 | if (skipped_read) { | |
479 | ClearPageChecked(page); | |
480 | ClearPageUptodate(page); | |
481 | } | |
1e51764a AB |
482 | /* |
483 | * Budgeting failed which means it would have to force | |
484 | * write-back but didn't, because we set the @fast flag in the | |
485 | * request. Write-back cannot be done now, while we have the | |
486 | * page locked, because it would deadlock. Unlock and free | |
487 | * everything and fall-back to slow-path. | |
488 | */ | |
489 | if (appending) { | |
6eb61d58 | 490 | ubifs_assert(c, mutex_is_locked(&ui->ui_mutex)); |
1e51764a AB |
491 | mutex_unlock(&ui->ui_mutex); |
492 | } | |
493 | unlock_page(page); | |
09cbfeaf | 494 | put_page(page); |
1e51764a | 495 | |
54566b2c | 496 | return write_begin_slow(mapping, pos, len, pagep, flags); |
1e51764a AB |
497 | } |
498 | ||
499 | /* | |
873a64c7 AB |
500 | * Whee, we acquired budgeting quickly - without involving |
501 | * garbage-collection, committing or forcing write-back. We return | |
1e51764a AB |
502 | * with @ui->ui_mutex locked if we are appending pages, and unlocked |
503 | * otherwise. This is an optimization (slightly hacky though). | |
504 | */ | |
505 | *pagep = page; | |
506 | return 0; | |
507 | ||
508 | } | |
509 | ||
510 | /** | |
511 | * cancel_budget - cancel budget. | |
512 | * @c: UBIFS file-system description object | |
513 | * @page: page to cancel budget for | |
514 | * @ui: UBIFS inode object the page belongs to | |
515 | * @appending: non-zero if the page is appended | |
516 | * | |
517 | * This is a helper function for a page write operation. It unlocks the | |
518 | * @ui->ui_mutex in case of appending. | |
519 | */ | |
520 | static void cancel_budget(struct ubifs_info *c, struct page *page, | |
521 | struct ubifs_inode *ui, int appending) | |
522 | { | |
523 | if (appending) { | |
524 | if (!ui->dirty) | |
525 | ubifs_release_dirty_inode_budget(c, ui); | |
526 | mutex_unlock(&ui->ui_mutex); | |
527 | } | |
528 | if (!PagePrivate(page)) { | |
529 | if (PageChecked(page)) | |
530 | release_new_page_budget(c); | |
531 | else | |
532 | release_existing_page_budget(c); | |
533 | } | |
534 | } | |
535 | ||
536 | static int ubifs_write_end(struct file *file, struct address_space *mapping, | |
537 | loff_t pos, unsigned len, unsigned copied, | |
538 | struct page *page, void *fsdata) | |
539 | { | |
540 | struct inode *inode = mapping->host; | |
541 | struct ubifs_inode *ui = ubifs_inode(inode); | |
542 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
543 | loff_t end_pos = pos + len; | |
544 | int appending = !!(end_pos > inode->i_size); | |
545 | ||
546 | dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld", | |
547 | inode->i_ino, pos, page->index, len, copied, inode->i_size); | |
548 | ||
09cbfeaf | 549 | if (unlikely(copied < len && len == PAGE_SIZE)) { |
1e51764a AB |
550 | /* |
551 | * VFS copied less data to the page that it intended and | |
552 | * declared in its '->write_begin()' call via the @len | |
553 | * argument. If the page was not up-to-date, and @len was | |
ea1754a0 | 554 | * @PAGE_SIZE, the 'ubifs_write_begin()' function did |
1e51764a AB |
555 | * not load it from the media (for optimization reasons). This |
556 | * means that part of the page contains garbage. So read the | |
557 | * page now. | |
558 | */ | |
559 | dbg_gen("copied %d instead of %d, read page and repeat", | |
560 | copied, len); | |
561 | cancel_budget(c, page, ui, appending); | |
6ed09c34 | 562 | ClearPageChecked(page); |
1e51764a AB |
563 | |
564 | /* | |
565 | * Return 0 to force VFS to repeat the whole operation, or the | |
873a64c7 | 566 | * error code if 'do_readpage()' fails. |
1e51764a AB |
567 | */ |
568 | copied = do_readpage(page); | |
569 | goto out; | |
570 | } | |
571 | ||
572 | if (!PagePrivate(page)) { | |
573 | SetPagePrivate(page); | |
574 | atomic_long_inc(&c->dirty_pg_cnt); | |
575 | __set_page_dirty_nobuffers(page); | |
576 | } | |
577 | ||
578 | if (appending) { | |
579 | i_size_write(inode, end_pos); | |
580 | ui->ui_size = end_pos; | |
581 | /* | |
582 | * Note, we do not set @I_DIRTY_PAGES (which means that the | |
583 | * inode has dirty pages), this has been done in | |
584 | * '__set_page_dirty_nobuffers()'. | |
585 | */ | |
586 | __mark_inode_dirty(inode, I_DIRTY_DATASYNC); | |
6eb61d58 | 587 | ubifs_assert(c, mutex_is_locked(&ui->ui_mutex)); |
1e51764a AB |
588 | mutex_unlock(&ui->ui_mutex); |
589 | } | |
590 | ||
591 | out: | |
592 | unlock_page(page); | |
09cbfeaf | 593 | put_page(page); |
1e51764a AB |
594 | return copied; |
595 | } | |
596 | ||
4793e7c5 AH |
597 | /** |
598 | * populate_page - copy data nodes into a page for bulk-read. | |
599 | * @c: UBIFS file-system description object | |
600 | * @page: page | |
601 | * @bu: bulk-read information | |
602 | * @n: next zbranch slot | |
603 | * | |
604 | * This function returns %0 on success and a negative error code on failure. | |
605 | */ | |
606 | static int populate_page(struct ubifs_info *c, struct page *page, | |
607 | struct bu_info *bu, int *n) | |
608 | { | |
5c0013c1 | 609 | int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0; |
4793e7c5 AH |
610 | struct inode *inode = page->mapping->host; |
611 | loff_t i_size = i_size_read(inode); | |
612 | unsigned int page_block; | |
613 | void *addr, *zaddr; | |
614 | pgoff_t end_index; | |
615 | ||
616 | dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx", | |
617 | inode->i_ino, page->index, i_size, page->flags); | |
618 | ||
619 | addr = zaddr = kmap(page); | |
620 | ||
09cbfeaf | 621 | end_index = (i_size - 1) >> PAGE_SHIFT; |
4793e7c5 | 622 | if (!i_size || page->index > end_index) { |
5c0013c1 | 623 | hole = 1; |
09cbfeaf | 624 | memset(addr, 0, PAGE_SIZE); |
4793e7c5 AH |
625 | goto out_hole; |
626 | } | |
627 | ||
628 | page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
629 | while (1) { | |
630 | int err, len, out_len, dlen; | |
631 | ||
5c0013c1 AH |
632 | if (nn >= bu->cnt) { |
633 | hole = 1; | |
4793e7c5 | 634 | memset(addr, 0, UBIFS_BLOCK_SIZE); |
5c0013c1 | 635 | } else if (key_block(c, &bu->zbranch[nn].key) == page_block) { |
4793e7c5 AH |
636 | struct ubifs_data_node *dn; |
637 | ||
638 | dn = bu->buf + (bu->zbranch[nn].offs - offs); | |
639 | ||
6eb61d58 | 640 | ubifs_assert(c, le64_to_cpu(dn->ch.sqnum) > |
4793e7c5 AH |
641 | ubifs_inode(inode)->creat_sqnum); |
642 | ||
643 | len = le32_to_cpu(dn->size); | |
644 | if (len <= 0 || len > UBIFS_BLOCK_SIZE) | |
645 | goto out_err; | |
646 | ||
647 | dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; | |
648 | out_len = UBIFS_BLOCK_SIZE; | |
7799953b RW |
649 | |
650 | if (ubifs_crypt_is_encrypted(inode)) { | |
651 | err = ubifs_decrypt(inode, dn, &dlen, page_block); | |
652 | if (err) | |
653 | goto out_err; | |
654 | } | |
655 | ||
235c362b | 656 | err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len, |
4793e7c5 AH |
657 | le16_to_cpu(dn->compr_type)); |
658 | if (err || len != out_len) | |
659 | goto out_err; | |
660 | ||
661 | if (len < UBIFS_BLOCK_SIZE) | |
662 | memset(addr + len, 0, UBIFS_BLOCK_SIZE - len); | |
663 | ||
664 | nn += 1; | |
4793e7c5 | 665 | read = (i << UBIFS_BLOCK_SHIFT) + len; |
5c0013c1 AH |
666 | } else if (key_block(c, &bu->zbranch[nn].key) < page_block) { |
667 | nn += 1; | |
668 | continue; | |
669 | } else { | |
670 | hole = 1; | |
671 | memset(addr, 0, UBIFS_BLOCK_SIZE); | |
4793e7c5 AH |
672 | } |
673 | if (++i >= UBIFS_BLOCKS_PER_PAGE) | |
674 | break; | |
675 | addr += UBIFS_BLOCK_SIZE; | |
676 | page_block += 1; | |
677 | } | |
678 | ||
679 | if (end_index == page->index) { | |
09cbfeaf | 680 | int len = i_size & (PAGE_SIZE - 1); |
4793e7c5 | 681 | |
ed382d58 | 682 | if (len && len < read) |
4793e7c5 AH |
683 | memset(zaddr + len, 0, read - len); |
684 | } | |
685 | ||
686 | out_hole: | |
687 | if (hole) { | |
688 | SetPageChecked(page); | |
689 | dbg_gen("hole"); | |
690 | } | |
691 | ||
692 | SetPageUptodate(page); | |
693 | ClearPageError(page); | |
694 | flush_dcache_page(page); | |
695 | kunmap(page); | |
696 | *n = nn; | |
697 | return 0; | |
698 | ||
699 | out_err: | |
700 | ClearPageUptodate(page); | |
701 | SetPageError(page); | |
702 | flush_dcache_page(page); | |
703 | kunmap(page); | |
235c362b | 704 | ubifs_err(c, "bad data node (block %u, inode %lu)", |
4793e7c5 AH |
705 | page_block, inode->i_ino); |
706 | return -EINVAL; | |
707 | } | |
708 | ||
709 | /** | |
710 | * ubifs_do_bulk_read - do bulk-read. | |
711 | * @c: UBIFS file-system description object | |
6c0c42cd AB |
712 | * @bu: bulk-read information |
713 | * @page1: first page to read | |
4793e7c5 AH |
714 | * |
715 | * This function returns %1 if the bulk-read is done, otherwise %0 is returned. | |
716 | */ | |
6c0c42cd AB |
717 | static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu, |
718 | struct page *page1) | |
4793e7c5 AH |
719 | { |
720 | pgoff_t offset = page1->index, end_index; | |
721 | struct address_space *mapping = page1->mapping; | |
722 | struct inode *inode = mapping->host; | |
723 | struct ubifs_inode *ui = ubifs_inode(inode); | |
4793e7c5 | 724 | int err, page_idx, page_cnt, ret = 0, n = 0; |
6c0c42cd | 725 | int allocate = bu->buf ? 0 : 1; |
4793e7c5 | 726 | loff_t isize; |
480a1a6a | 727 | gfp_t ra_gfp_mask = readahead_gfp_mask(mapping) & ~__GFP_FS; |
4793e7c5 | 728 | |
4793e7c5 AH |
729 | err = ubifs_tnc_get_bu_keys(c, bu); |
730 | if (err) | |
731 | goto out_warn; | |
732 | ||
733 | if (bu->eof) { | |
734 | /* Turn off bulk-read at the end of the file */ | |
735 | ui->read_in_a_row = 1; | |
736 | ui->bulk_read = 0; | |
737 | } | |
738 | ||
739 | page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
740 | if (!page_cnt) { | |
741 | /* | |
742 | * This happens when there are multiple blocks per page and the | |
743 | * blocks for the first page we are looking for, are not | |
744 | * together. If all the pages were like this, bulk-read would | |
745 | * reduce performance, so we turn it off for a while. | |
746 | */ | |
6c0c42cd | 747 | goto out_bu_off; |
4793e7c5 AH |
748 | } |
749 | ||
750 | if (bu->cnt) { | |
6c0c42cd AB |
751 | if (allocate) { |
752 | /* | |
753 | * Allocate bulk-read buffer depending on how many data | |
754 | * nodes we are going to read. | |
755 | */ | |
756 | bu->buf_len = bu->zbranch[bu->cnt - 1].offs + | |
757 | bu->zbranch[bu->cnt - 1].len - | |
758 | bu->zbranch[0].offs; | |
6eb61d58 RW |
759 | ubifs_assert(c, bu->buf_len > 0); |
760 | ubifs_assert(c, bu->buf_len <= c->leb_size); | |
6c0c42cd AB |
761 | bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN); |
762 | if (!bu->buf) | |
763 | goto out_bu_off; | |
764 | } | |
765 | ||
4793e7c5 AH |
766 | err = ubifs_tnc_bulk_read(c, bu); |
767 | if (err) | |
768 | goto out_warn; | |
769 | } | |
770 | ||
771 | err = populate_page(c, page1, bu, &n); | |
772 | if (err) | |
773 | goto out_warn; | |
774 | ||
775 | unlock_page(page1); | |
776 | ret = 1; | |
777 | ||
778 | isize = i_size_read(inode); | |
779 | if (isize == 0) | |
780 | goto out_free; | |
09cbfeaf | 781 | end_index = ((isize - 1) >> PAGE_SHIFT); |
4793e7c5 AH |
782 | |
783 | for (page_idx = 1; page_idx < page_cnt; page_idx++) { | |
784 | pgoff_t page_offset = offset + page_idx; | |
785 | struct page *page; | |
786 | ||
787 | if (page_offset > end_index) | |
788 | break; | |
480a1a6a | 789 | page = find_or_create_page(mapping, page_offset, ra_gfp_mask); |
4793e7c5 AH |
790 | if (!page) |
791 | break; | |
792 | if (!PageUptodate(page)) | |
793 | err = populate_page(c, page, bu, &n); | |
794 | unlock_page(page); | |
09cbfeaf | 795 | put_page(page); |
4793e7c5 AH |
796 | if (err) |
797 | break; | |
798 | } | |
799 | ||
800 | ui->last_page_read = offset + page_idx - 1; | |
801 | ||
802 | out_free: | |
6c0c42cd AB |
803 | if (allocate) |
804 | kfree(bu->buf); | |
4793e7c5 AH |
805 | return ret; |
806 | ||
807 | out_warn: | |
235c362b | 808 | ubifs_warn(c, "ignoring error %d and skipping bulk-read", err); |
4793e7c5 | 809 | goto out_free; |
6c0c42cd AB |
810 | |
811 | out_bu_off: | |
812 | ui->read_in_a_row = ui->bulk_read = 0; | |
813 | goto out_free; | |
4793e7c5 AH |
814 | } |
815 | ||
816 | /** | |
817 | * ubifs_bulk_read - determine whether to bulk-read and, if so, do it. | |
818 | * @page: page from which to start bulk-read. | |
819 | * | |
820 | * Some flash media are capable of reading sequentially at faster rates. UBIFS | |
821 | * bulk-read facility is designed to take advantage of that, by reading in one | |
822 | * go consecutive data nodes that are also located consecutively in the same | |
823 | * LEB. This function returns %1 if a bulk-read is done and %0 otherwise. | |
824 | */ | |
825 | static int ubifs_bulk_read(struct page *page) | |
826 | { | |
827 | struct inode *inode = page->mapping->host; | |
828 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
829 | struct ubifs_inode *ui = ubifs_inode(inode); | |
830 | pgoff_t index = page->index, last_page_read = ui->last_page_read; | |
6c0c42cd | 831 | struct bu_info *bu; |
3477d204 | 832 | int err = 0, allocated = 0; |
4793e7c5 AH |
833 | |
834 | ui->last_page_read = index; | |
4793e7c5 AH |
835 | if (!c->bulk_read) |
836 | return 0; | |
6c0c42cd | 837 | |
4793e7c5 | 838 | /* |
3477d204 AB |
839 | * Bulk-read is protected by @ui->ui_mutex, but it is an optimization, |
840 | * so don't bother if we cannot lock the mutex. | |
4793e7c5 AH |
841 | */ |
842 | if (!mutex_trylock(&ui->ui_mutex)) | |
843 | return 0; | |
6c0c42cd | 844 | |
4793e7c5 AH |
845 | if (index != last_page_read + 1) { |
846 | /* Turn off bulk-read if we stop reading sequentially */ | |
847 | ui->read_in_a_row = 1; | |
848 | if (ui->bulk_read) | |
849 | ui->bulk_read = 0; | |
850 | goto out_unlock; | |
851 | } | |
6c0c42cd | 852 | |
4793e7c5 AH |
853 | if (!ui->bulk_read) { |
854 | ui->read_in_a_row += 1; | |
855 | if (ui->read_in_a_row < 3) | |
856 | goto out_unlock; | |
857 | /* Three reads in a row, so switch on bulk-read */ | |
858 | ui->bulk_read = 1; | |
859 | } | |
6c0c42cd | 860 | |
3477d204 AB |
861 | /* |
862 | * If possible, try to use pre-allocated bulk-read information, which | |
863 | * is protected by @c->bu_mutex. | |
864 | */ | |
865 | if (mutex_trylock(&c->bu_mutex)) | |
866 | bu = &c->bu; | |
867 | else { | |
868 | bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN); | |
869 | if (!bu) | |
870 | goto out_unlock; | |
871 | ||
872 | bu->buf = NULL; | |
873 | allocated = 1; | |
874 | } | |
6c0c42cd | 875 | |
6c0c42cd AB |
876 | bu->buf_len = c->max_bu_buf_len; |
877 | data_key_init(c, &bu->key, inode->i_ino, | |
878 | page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT); | |
6c0c42cd | 879 | err = ubifs_do_bulk_read(c, bu, page); |
3477d204 AB |
880 | |
881 | if (!allocated) | |
882 | mutex_unlock(&c->bu_mutex); | |
883 | else | |
884 | kfree(bu); | |
6c0c42cd | 885 | |
4793e7c5 AH |
886 | out_unlock: |
887 | mutex_unlock(&ui->ui_mutex); | |
6c0c42cd | 888 | return err; |
4793e7c5 AH |
889 | } |
890 | ||
1e51764a AB |
891 | static int ubifs_readpage(struct file *file, struct page *page) |
892 | { | |
4793e7c5 AH |
893 | if (ubifs_bulk_read(page)) |
894 | return 0; | |
1e51764a AB |
895 | do_readpage(page); |
896 | unlock_page(page); | |
897 | return 0; | |
898 | } | |
899 | ||
900 | static int do_writepage(struct page *page, int len) | |
901 | { | |
902 | int err = 0, i, blen; | |
903 | unsigned int block; | |
904 | void *addr; | |
905 | union ubifs_key key; | |
906 | struct inode *inode = page->mapping->host; | |
907 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
908 | ||
909 | #ifdef UBIFS_DEBUG | |
a0fd5951 | 910 | struct ubifs_inode *ui = ubifs_inode(inode); |
1e51764a | 911 | spin_lock(&ui->ui_lock); |
6eb61d58 | 912 | ubifs_assert(c, page->index <= ui->synced_i_size >> PAGE_SHIFT); |
1e51764a AB |
913 | spin_unlock(&ui->ui_lock); |
914 | #endif | |
915 | ||
916 | /* Update radix tree tags */ | |
917 | set_page_writeback(page); | |
918 | ||
919 | addr = kmap(page); | |
920 | block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; | |
921 | i = 0; | |
922 | while (len) { | |
923 | blen = min_t(int, len, UBIFS_BLOCK_SIZE); | |
924 | data_key_init(c, &key, inode->i_ino, block); | |
925 | err = ubifs_jnl_write_data(c, inode, &key, addr, blen); | |
926 | if (err) | |
927 | break; | |
928 | if (++i >= UBIFS_BLOCKS_PER_PAGE) | |
929 | break; | |
930 | block += 1; | |
931 | addr += blen; | |
932 | len -= blen; | |
933 | } | |
934 | if (err) { | |
935 | SetPageError(page); | |
235c362b | 936 | ubifs_err(c, "cannot write page %lu of inode %lu, error %d", |
1e51764a AB |
937 | page->index, inode->i_ino, err); |
938 | ubifs_ro_mode(c, err); | |
939 | } | |
940 | ||
6eb61d58 | 941 | ubifs_assert(c, PagePrivate(page)); |
1e51764a AB |
942 | if (PageChecked(page)) |
943 | release_new_page_budget(c); | |
944 | else | |
945 | release_existing_page_budget(c); | |
946 | ||
947 | atomic_long_dec(&c->dirty_pg_cnt); | |
948 | ClearPagePrivate(page); | |
949 | ClearPageChecked(page); | |
950 | ||
951 | kunmap(page); | |
952 | unlock_page(page); | |
953 | end_page_writeback(page); | |
954 | return err; | |
955 | } | |
956 | ||
957 | /* | |
958 | * When writing-back dirty inodes, VFS first writes-back pages belonging to the | |
959 | * inode, then the inode itself. For UBIFS this may cause a problem. Consider a | |
960 | * situation when a we have an inode with size 0, then a megabyte of data is | |
961 | * appended to the inode, then write-back starts and flushes some amount of the | |
962 | * dirty pages, the journal becomes full, commit happens and finishes, and then | |
963 | * an unclean reboot happens. When the file system is mounted next time, the | |
964 | * inode size would still be 0, but there would be many pages which are beyond | |
965 | * the inode size, they would be indexed and consume flash space. Because the | |
966 | * journal has been committed, the replay would not be able to detect this | |
967 | * situation and correct the inode size. This means UBIFS would have to scan | |
968 | * whole index and correct all inode sizes, which is long an unacceptable. | |
969 | * | |
970 | * To prevent situations like this, UBIFS writes pages back only if they are | |
7d4e9ccb | 971 | * within the last synchronized inode size, i.e. the size which has been |
1e51764a AB |
972 | * written to the flash media last time. Otherwise, UBIFS forces inode |
973 | * write-back, thus making sure the on-flash inode contains current inode size, | |
974 | * and then keeps writing pages back. | |
975 | * | |
976 | * Some locking issues explanation. 'ubifs_writepage()' first is called with | |
977 | * the page locked, and it locks @ui_mutex. However, write-back does take inode | |
978 | * @i_mutex, which means other VFS operations may be run on this inode at the | |
979 | * same time. And the problematic one is truncation to smaller size, from where | |
c4361570 AB |
980 | * we have to call 'truncate_setsize()', which first changes @inode->i_size, |
981 | * then drops the truncated pages. And while dropping the pages, it takes the | |
982 | * page lock. This means that 'do_truncation()' cannot call 'truncate_setsize()' | |
983 | * with @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'. | |
984 | * This means that @inode->i_size is changed while @ui_mutex is unlocked. | |
1e51764a | 985 | * |
2c27c65e CH |
986 | * XXX(truncate): with the new truncate sequence this is not true anymore, |
987 | * and the calls to truncate_setsize can be move around freely. They should | |
988 | * be moved to the very end of the truncate sequence. | |
15c6fd97 | 989 | * |
1e51764a AB |
990 | * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond |
991 | * inode size. How do we do this if @inode->i_size may became smaller while we | |
992 | * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the | |
993 | * @ui->ui_isize "shadow" field which UBIFS uses instead of @inode->i_size | |
994 | * internally and updates it under @ui_mutex. | |
995 | * | |
996 | * Q: why we do not worry that if we race with truncation, we may end up with a | |
997 | * situation when the inode is truncated while we are in the middle of | |
998 | * 'do_writepage()', so we do write beyond inode size? | |
999 | * A: If we are in the middle of 'do_writepage()', truncation would be locked | |
1000 | * on the page lock and it would not write the truncated inode node to the | |
1001 | * journal before we have finished. | |
1002 | */ | |
1003 | static int ubifs_writepage(struct page *page, struct writeback_control *wbc) | |
1004 | { | |
1005 | struct inode *inode = page->mapping->host; | |
6eb61d58 | 1006 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1e51764a AB |
1007 | struct ubifs_inode *ui = ubifs_inode(inode); |
1008 | loff_t i_size = i_size_read(inode), synced_i_size; | |
09cbfeaf KS |
1009 | pgoff_t end_index = i_size >> PAGE_SHIFT; |
1010 | int err, len = i_size & (PAGE_SIZE - 1); | |
1e51764a AB |
1011 | void *kaddr; |
1012 | ||
1013 | dbg_gen("ino %lu, pg %lu, pg flags %#lx", | |
1014 | inode->i_ino, page->index, page->flags); | |
6eb61d58 | 1015 | ubifs_assert(c, PagePrivate(page)); |
1e51764a AB |
1016 | |
1017 | /* Is the page fully outside @i_size? (truncate in progress) */ | |
1018 | if (page->index > end_index || (page->index == end_index && !len)) { | |
1019 | err = 0; | |
1020 | goto out_unlock; | |
1021 | } | |
1022 | ||
1023 | spin_lock(&ui->ui_lock); | |
1024 | synced_i_size = ui->synced_i_size; | |
1025 | spin_unlock(&ui->ui_lock); | |
1026 | ||
1027 | /* Is the page fully inside @i_size? */ | |
1028 | if (page->index < end_index) { | |
09cbfeaf | 1029 | if (page->index >= synced_i_size >> PAGE_SHIFT) { |
a9185b41 | 1030 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a AB |
1031 | if (err) |
1032 | goto out_unlock; | |
1033 | /* | |
1034 | * The inode has been written, but the write-buffer has | |
1035 | * not been synchronized, so in case of an unclean | |
1036 | * reboot we may end up with some pages beyond inode | |
1037 | * size, but they would be in the journal (because | |
1038 | * commit flushes write buffers) and recovery would deal | |
1039 | * with this. | |
1040 | */ | |
1041 | } | |
09cbfeaf | 1042 | return do_writepage(page, PAGE_SIZE); |
1e51764a AB |
1043 | } |
1044 | ||
1045 | /* | |
1046 | * The page straddles @i_size. It must be zeroed out on each and every | |
1047 | * writepage invocation because it may be mmapped. "A file is mapped | |
1048 | * in multiples of the page size. For a file that is not a multiple of | |
1049 | * the page size, the remaining memory is zeroed when mapped, and | |
1050 | * writes to that region are not written out to the file." | |
1051 | */ | |
a1c7c137 | 1052 | kaddr = kmap_atomic(page); |
09cbfeaf | 1053 | memset(kaddr + len, 0, PAGE_SIZE - len); |
1e51764a | 1054 | flush_dcache_page(page); |
a1c7c137 | 1055 | kunmap_atomic(kaddr); |
1e51764a AB |
1056 | |
1057 | if (i_size > synced_i_size) { | |
a9185b41 | 1058 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a AB |
1059 | if (err) |
1060 | goto out_unlock; | |
1061 | } | |
1062 | ||
1063 | return do_writepage(page, len); | |
1064 | ||
1065 | out_unlock: | |
1066 | unlock_page(page); | |
1067 | return err; | |
1068 | } | |
1069 | ||
1070 | /** | |
1071 | * do_attr_changes - change inode attributes. | |
1072 | * @inode: inode to change attributes for | |
1073 | * @attr: describes attributes to change | |
1074 | */ | |
1075 | static void do_attr_changes(struct inode *inode, const struct iattr *attr) | |
1076 | { | |
1077 | if (attr->ia_valid & ATTR_UID) | |
1078 | inode->i_uid = attr->ia_uid; | |
1079 | if (attr->ia_valid & ATTR_GID) | |
1080 | inode->i_gid = attr->ia_gid; | |
1081 | if (attr->ia_valid & ATTR_ATIME) | |
95582b00 DD |
1082 | inode->i_atime = timespec64_trunc(attr->ia_atime, |
1083 | inode->i_sb->s_time_gran); | |
1e51764a | 1084 | if (attr->ia_valid & ATTR_MTIME) |
95582b00 DD |
1085 | inode->i_mtime = timespec64_trunc(attr->ia_mtime, |
1086 | inode->i_sb->s_time_gran); | |
1e51764a | 1087 | if (attr->ia_valid & ATTR_CTIME) |
95582b00 DD |
1088 | inode->i_ctime = timespec64_trunc(attr->ia_ctime, |
1089 | inode->i_sb->s_time_gran); | |
1e51764a AB |
1090 | if (attr->ia_valid & ATTR_MODE) { |
1091 | umode_t mode = attr->ia_mode; | |
1092 | ||
1093 | if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) | |
1094 | mode &= ~S_ISGID; | |
1095 | inode->i_mode = mode; | |
1096 | } | |
1097 | } | |
1098 | ||
1099 | /** | |
1100 | * do_truncation - truncate an inode. | |
1101 | * @c: UBIFS file-system description object | |
1102 | * @inode: inode to truncate | |
1103 | * @attr: inode attribute changes description | |
1104 | * | |
1105 | * This function implements VFS '->setattr()' call when the inode is truncated | |
1106 | * to a smaller size. Returns zero in case of success and a negative error code | |
1107 | * in case of failure. | |
1108 | */ | |
1109 | static int do_truncation(struct ubifs_info *c, struct inode *inode, | |
1110 | const struct iattr *attr) | |
1111 | { | |
1112 | int err; | |
1113 | struct ubifs_budget_req req; | |
1114 | loff_t old_size = inode->i_size, new_size = attr->ia_size; | |
04da11bf | 1115 | int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1; |
1e51764a AB |
1116 | struct ubifs_inode *ui = ubifs_inode(inode); |
1117 | ||
1118 | dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size); | |
1119 | memset(&req, 0, sizeof(struct ubifs_budget_req)); | |
1120 | ||
1121 | /* | |
1122 | * If this is truncation to a smaller size, and we do not truncate on a | |
1123 | * block boundary, budget for changing one data block, because the last | |
1124 | * block will be re-written. | |
1125 | */ | |
1126 | if (new_size & (UBIFS_BLOCK_SIZE - 1)) | |
1127 | req.dirtied_page = 1; | |
1128 | ||
1129 | req.dirtied_ino = 1; | |
1130 | /* A funny way to budget for truncation node */ | |
1131 | req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ; | |
1132 | err = ubifs_budget_space(c, &req); | |
04da11bf AB |
1133 | if (err) { |
1134 | /* | |
1135 | * Treat truncations to zero as deletion and always allow them, | |
1136 | * just like we do for '->unlink()'. | |
1137 | */ | |
1138 | if (new_size || err != -ENOSPC) | |
1139 | return err; | |
1140 | budgeted = 0; | |
1141 | } | |
1e51764a | 1142 | |
2c27c65e | 1143 | truncate_setsize(inode, new_size); |
1e51764a AB |
1144 | |
1145 | if (offset) { | |
09cbfeaf | 1146 | pgoff_t index = new_size >> PAGE_SHIFT; |
1e51764a AB |
1147 | struct page *page; |
1148 | ||
1149 | page = find_lock_page(inode->i_mapping, index); | |
1150 | if (page) { | |
1151 | if (PageDirty(page)) { | |
1152 | /* | |
1153 | * 'ubifs_jnl_truncate()' will try to truncate | |
1154 | * the last data node, but it contains | |
1155 | * out-of-date data because the page is dirty. | |
1156 | * Write the page now, so that | |
1157 | * 'ubifs_jnl_truncate()' will see an already | |
1158 | * truncated (and up to date) data node. | |
1159 | */ | |
6eb61d58 | 1160 | ubifs_assert(c, PagePrivate(page)); |
1e51764a AB |
1161 | |
1162 | clear_page_dirty_for_io(page); | |
1163 | if (UBIFS_BLOCKS_PER_PAGE_SHIFT) | |
1164 | offset = new_size & | |
09cbfeaf | 1165 | (PAGE_SIZE - 1); |
1e51764a | 1166 | err = do_writepage(page, offset); |
09cbfeaf | 1167 | put_page(page); |
1e51764a AB |
1168 | if (err) |
1169 | goto out_budg; | |
1170 | /* | |
1171 | * We could now tell 'ubifs_jnl_truncate()' not | |
1172 | * to read the last block. | |
1173 | */ | |
1174 | } else { | |
1175 | /* | |
1176 | * We could 'kmap()' the page and pass the data | |
1177 | * to 'ubifs_jnl_truncate()' to save it from | |
1178 | * having to read it. | |
1179 | */ | |
1180 | unlock_page(page); | |
09cbfeaf | 1181 | put_page(page); |
1e51764a AB |
1182 | } |
1183 | } | |
1184 | } | |
1185 | ||
1186 | mutex_lock(&ui->ui_mutex); | |
1187 | ui->ui_size = inode->i_size; | |
1188 | /* Truncation changes inode [mc]time */ | |
607a11ad | 1189 | inode->i_mtime = inode->i_ctime = current_time(inode); |
873a64c7 | 1190 | /* Other attributes may be changed at the same time as well */ |
1e51764a | 1191 | do_attr_changes(inode, attr); |
1e51764a AB |
1192 | err = ubifs_jnl_truncate(c, inode, old_size, new_size); |
1193 | mutex_unlock(&ui->ui_mutex); | |
873a64c7 | 1194 | |
1e51764a | 1195 | out_budg: |
04da11bf AB |
1196 | if (budgeted) |
1197 | ubifs_release_budget(c, &req); | |
1198 | else { | |
b137545c | 1199 | c->bi.nospace = c->bi.nospace_rp = 0; |
04da11bf AB |
1200 | smp_wmb(); |
1201 | } | |
1e51764a AB |
1202 | return err; |
1203 | } | |
1204 | ||
1205 | /** | |
1206 | * do_setattr - change inode attributes. | |
1207 | * @c: UBIFS file-system description object | |
1208 | * @inode: inode to change attributes for | |
1209 | * @attr: inode attribute changes description | |
1210 | * | |
1211 | * This function implements VFS '->setattr()' call for all cases except | |
1212 | * truncations to smaller size. Returns zero in case of success and a negative | |
1213 | * error code in case of failure. | |
1214 | */ | |
1215 | static int do_setattr(struct ubifs_info *c, struct inode *inode, | |
1216 | const struct iattr *attr) | |
1217 | { | |
1218 | int err, release; | |
1219 | loff_t new_size = attr->ia_size; | |
1220 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1221 | struct ubifs_budget_req req = { .dirtied_ino = 1, | |
dab4b4d2 | 1222 | .dirtied_ino_d = ALIGN(ui->data_len, 8) }; |
1e51764a AB |
1223 | |
1224 | err = ubifs_budget_space(c, &req); | |
1225 | if (err) | |
1226 | return err; | |
1227 | ||
1228 | if (attr->ia_valid & ATTR_SIZE) { | |
1229 | dbg_gen("size %lld -> %lld", inode->i_size, new_size); | |
2c27c65e | 1230 | truncate_setsize(inode, new_size); |
1e51764a AB |
1231 | } |
1232 | ||
1233 | mutex_lock(&ui->ui_mutex); | |
1234 | if (attr->ia_valid & ATTR_SIZE) { | |
1235 | /* Truncation changes inode [mc]time */ | |
607a11ad | 1236 | inode->i_mtime = inode->i_ctime = current_time(inode); |
2c27c65e | 1237 | /* 'truncate_setsize()' changed @i_size, update @ui_size */ |
1e51764a AB |
1238 | ui->ui_size = inode->i_size; |
1239 | } | |
1240 | ||
1241 | do_attr_changes(inode, attr); | |
1242 | ||
1243 | release = ui->dirty; | |
1244 | if (attr->ia_valid & ATTR_SIZE) | |
1245 | /* | |
1246 | * Inode length changed, so we have to make sure | |
1247 | * @I_DIRTY_DATASYNC is set. | |
1248 | */ | |
f3556254 | 1249 | __mark_inode_dirty(inode, I_DIRTY_DATASYNC); |
1e51764a AB |
1250 | else |
1251 | mark_inode_dirty_sync(inode); | |
1252 | mutex_unlock(&ui->ui_mutex); | |
1253 | ||
1254 | if (release) | |
1255 | ubifs_release_budget(c, &req); | |
1256 | if (IS_SYNC(inode)) | |
a9185b41 | 1257 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a | 1258 | return err; |
1e51764a AB |
1259 | } |
1260 | ||
1261 | int ubifs_setattr(struct dentry *dentry, struct iattr *attr) | |
1262 | { | |
1263 | int err; | |
2b0143b5 | 1264 | struct inode *inode = d_inode(dentry); |
1e51764a AB |
1265 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1266 | ||
7d32c2bb AB |
1267 | dbg_gen("ino %lu, mode %#x, ia_valid %#x", |
1268 | inode->i_ino, inode->i_mode, attr->ia_valid); | |
31051c85 | 1269 | err = setattr_prepare(dentry, attr); |
1e51764a AB |
1270 | if (err) |
1271 | return err; | |
1272 | ||
d808efb4 | 1273 | err = dbg_check_synced_i_size(c, inode); |
1e51764a AB |
1274 | if (err) |
1275 | return err; | |
1276 | ||
252153ba EB |
1277 | err = fscrypt_prepare_setattr(dentry, attr); |
1278 | if (err) | |
1279 | return err; | |
4afb9996 | 1280 | |
1e51764a AB |
1281 | if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size < inode->i_size) |
1282 | /* Truncation to a smaller size */ | |
1283 | err = do_truncation(c, inode, attr); | |
1284 | else | |
1285 | err = do_setattr(c, inode, attr); | |
1286 | ||
1287 | return err; | |
1288 | } | |
1289 | ||
d47992f8 LC |
1290 | static void ubifs_invalidatepage(struct page *page, unsigned int offset, |
1291 | unsigned int length) | |
1e51764a AB |
1292 | { |
1293 | struct inode *inode = page->mapping->host; | |
1294 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
1295 | ||
6eb61d58 | 1296 | ubifs_assert(c, PagePrivate(page)); |
09cbfeaf | 1297 | if (offset || length < PAGE_SIZE) |
1e51764a AB |
1298 | /* Partial page remains dirty */ |
1299 | return; | |
1300 | ||
1301 | if (PageChecked(page)) | |
1302 | release_new_page_budget(c); | |
1303 | else | |
1304 | release_existing_page_budget(c); | |
1305 | ||
1306 | atomic_long_dec(&c->dirty_pg_cnt); | |
1307 | ClearPagePrivate(page); | |
1308 | ClearPageChecked(page); | |
1309 | } | |
1310 | ||
02c24a82 | 1311 | int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
1e51764a | 1312 | { |
7ea80859 | 1313 | struct inode *inode = file->f_mapping->host; |
1e51764a AB |
1314 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1315 | int err; | |
1316 | ||
1317 | dbg_gen("syncing inode %lu", inode->i_ino); | |
1318 | ||
3b2f9a01 AB |
1319 | if (c->ro_mount) |
1320 | /* | |
1321 | * For some really strange reasons VFS does not filter out | |
1322 | * 'fsync()' for R/O mounted file-systems as per 2.6.39. | |
1323 | */ | |
78530bf7 AB |
1324 | return 0; |
1325 | ||
3b49c9a1 | 1326 | err = file_write_and_wait_range(file, start, end); |
02c24a82 JB |
1327 | if (err) |
1328 | return err; | |
5955102c | 1329 | inode_lock(inode); |
02c24a82 JB |
1330 | |
1331 | /* Synchronize the inode unless this is a 'datasync()' call. */ | |
1e51764a | 1332 | if (!datasync || (inode->i_state & I_DIRTY_DATASYNC)) { |
a9185b41 | 1333 | err = inode->i_sb->s_op->write_inode(inode, NULL); |
1e51764a | 1334 | if (err) |
02c24a82 | 1335 | goto out; |
1e51764a AB |
1336 | } |
1337 | ||
1338 | /* | |
1339 | * Nodes related to this inode may still sit in a write-buffer. Flush | |
1340 | * them. | |
1341 | */ | |
1342 | err = ubifs_sync_wbufs_by_inode(c, inode); | |
02c24a82 | 1343 | out: |
5955102c | 1344 | inode_unlock(inode); |
02c24a82 | 1345 | return err; |
1e51764a AB |
1346 | } |
1347 | ||
1348 | /** | |
1349 | * mctime_update_needed - check if mtime or ctime update is needed. | |
1350 | * @inode: the inode to do the check for | |
1351 | * @now: current time | |
1352 | * | |
1353 | * This helper function checks if the inode mtime/ctime should be updated or | |
1354 | * not. If current values of the time-stamps are within the UBIFS inode time | |
1355 | * granularity, they are not updated. This is an optimization. | |
1356 | */ | |
1357 | static inline int mctime_update_needed(const struct inode *inode, | |
0eca0b80 | 1358 | const struct timespec64 *now) |
1e51764a | 1359 | { |
0eca0b80 AB |
1360 | if (!timespec64_equal(&inode->i_mtime, now) || |
1361 | !timespec64_equal(&inode->i_ctime, now)) | |
1e51764a AB |
1362 | return 1; |
1363 | return 0; | |
1364 | } | |
1365 | ||
8c1c5f26 DY |
1366 | /** |
1367 | * ubifs_update_time - update time of inode. | |
1368 | * @inode: inode to update | |
1369 | * | |
1370 | * This function updates time of the inode. | |
1371 | */ | |
95582b00 | 1372 | int ubifs_update_time(struct inode *inode, struct timespec64 *time, |
8c1c5f26 DY |
1373 | int flags) |
1374 | { | |
1375 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1376 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
1377 | struct ubifs_budget_req req = { .dirtied_ino = 1, | |
1378 | .dirtied_ino_d = ALIGN(ui->data_len, 8) }; | |
1379 | int iflags = I_DIRTY_TIME; | |
1380 | int err, release; | |
1381 | ||
e3d73dea SH |
1382 | if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT)) |
1383 | return generic_update_time(inode, time, flags); | |
1384 | ||
8c1c5f26 DY |
1385 | err = ubifs_budget_space(c, &req); |
1386 | if (err) | |
1387 | return err; | |
1388 | ||
1389 | mutex_lock(&ui->ui_mutex); | |
1390 | if (flags & S_ATIME) | |
1391 | inode->i_atime = *time; | |
1392 | if (flags & S_CTIME) | |
1393 | inode->i_ctime = *time; | |
1394 | if (flags & S_MTIME) | |
1395 | inode->i_mtime = *time; | |
1396 | ||
1751e8a6 | 1397 | if (!(inode->i_sb->s_flags & SB_LAZYTIME)) |
8c1c5f26 DY |
1398 | iflags |= I_DIRTY_SYNC; |
1399 | ||
1400 | release = ui->dirty; | |
1401 | __mark_inode_dirty(inode, iflags); | |
1402 | mutex_unlock(&ui->ui_mutex); | |
1403 | if (release) | |
1404 | ubifs_release_budget(c, &req); | |
1405 | return 0; | |
1406 | } | |
8c1c5f26 | 1407 | |
1e51764a | 1408 | /** |
ec037dfc | 1409 | * update_mctime - update mtime and ctime of an inode. |
1e51764a AB |
1410 | * @inode: inode to update |
1411 | * | |
1412 | * This function updates mtime and ctime of the inode if it is not equivalent to | |
1413 | * current time. Returns zero in case of success and a negative error code in | |
1414 | * case of failure. | |
1415 | */ | |
f5674c31 | 1416 | static int update_mctime(struct inode *inode) |
1e51764a | 1417 | { |
0eca0b80 | 1418 | struct timespec64 now = current_time(inode); |
1e51764a | 1419 | struct ubifs_inode *ui = ubifs_inode(inode); |
f5674c31 | 1420 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
1e51764a AB |
1421 | |
1422 | if (mctime_update_needed(inode, &now)) { | |
1423 | int err, release; | |
1424 | struct ubifs_budget_req req = { .dirtied_ino = 1, | |
dab4b4d2 | 1425 | .dirtied_ino_d = ALIGN(ui->data_len, 8) }; |
1e51764a AB |
1426 | |
1427 | err = ubifs_budget_space(c, &req); | |
1428 | if (err) | |
1429 | return err; | |
1430 | ||
1431 | mutex_lock(&ui->ui_mutex); | |
607a11ad | 1432 | inode->i_mtime = inode->i_ctime = current_time(inode); |
1e51764a AB |
1433 | release = ui->dirty; |
1434 | mark_inode_dirty_sync(inode); | |
1435 | mutex_unlock(&ui->ui_mutex); | |
1436 | if (release) | |
1437 | ubifs_release_budget(c, &req); | |
1438 | } | |
1439 | ||
1440 | return 0; | |
1441 | } | |
1442 | ||
f5674c31 | 1443 | static ssize_t ubifs_write_iter(struct kiocb *iocb, struct iov_iter *from) |
1e51764a | 1444 | { |
f5674c31 | 1445 | int err = update_mctime(file_inode(iocb->ki_filp)); |
1e51764a AB |
1446 | if (err) |
1447 | return err; | |
1448 | ||
f5674c31 | 1449 | return generic_file_write_iter(iocb, from); |
1e51764a AB |
1450 | } |
1451 | ||
1452 | static int ubifs_set_page_dirty(struct page *page) | |
1453 | { | |
1454 | int ret; | |
6eb61d58 RW |
1455 | struct inode *inode = page->mapping->host; |
1456 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
1e51764a AB |
1457 | |
1458 | ret = __set_page_dirty_nobuffers(page); | |
1459 | /* | |
1460 | * An attempt to dirty a page without budgeting for it - should not | |
1461 | * happen. | |
1462 | */ | |
6eb61d58 | 1463 | ubifs_assert(c, ret == 0); |
1e51764a AB |
1464 | return ret; |
1465 | } | |
1466 | ||
4ac1c17b KS |
1467 | #ifdef CONFIG_MIGRATION |
1468 | static int ubifs_migrate_page(struct address_space *mapping, | |
1469 | struct page *newpage, struct page *page, enum migrate_mode mode) | |
1470 | { | |
1471 | int rc; | |
1472 | ||
37109694 | 1473 | rc = migrate_page_move_mapping(mapping, newpage, page, 0); |
4ac1c17b KS |
1474 | if (rc != MIGRATEPAGE_SUCCESS) |
1475 | return rc; | |
1476 | ||
1477 | if (PagePrivate(page)) { | |
1478 | ClearPagePrivate(page); | |
1479 | SetPagePrivate(newpage); | |
1480 | } | |
1481 | ||
2916ecc0 JG |
1482 | if (mode != MIGRATE_SYNC_NO_COPY) |
1483 | migrate_page_copy(newpage, page); | |
1484 | else | |
1485 | migrate_page_states(newpage, page); | |
4ac1c17b KS |
1486 | return MIGRATEPAGE_SUCCESS; |
1487 | } | |
1488 | #endif | |
1489 | ||
1e51764a AB |
1490 | static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags) |
1491 | { | |
6eb61d58 RW |
1492 | struct inode *inode = page->mapping->host; |
1493 | struct ubifs_info *c = inode->i_sb->s_fs_info; | |
1494 | ||
1e51764a AB |
1495 | /* |
1496 | * An attempt to release a dirty page without budgeting for it - should | |
1497 | * not happen. | |
1498 | */ | |
1499 | if (PageWriteback(page)) | |
1500 | return 0; | |
6eb61d58 RW |
1501 | ubifs_assert(c, PagePrivate(page)); |
1502 | ubifs_assert(c, 0); | |
1e51764a AB |
1503 | ClearPagePrivate(page); |
1504 | ClearPageChecked(page); | |
1505 | return 1; | |
1506 | } | |
1507 | ||
1508 | /* | |
c4361570 AB |
1509 | * mmap()d file has taken write protection fault and is being made writable. |
1510 | * UBIFS must ensure page is budgeted for. | |
1e51764a | 1511 | */ |
31c49eac | 1512 | static vm_fault_t ubifs_vm_page_mkwrite(struct vm_fault *vmf) |
1e51764a | 1513 | { |
c2ec175c | 1514 | struct page *page = vmf->page; |
11bac800 | 1515 | struct inode *inode = file_inode(vmf->vma->vm_file); |
1e51764a | 1516 | struct ubifs_info *c = inode->i_sb->s_fs_info; |
0eca0b80 | 1517 | struct timespec64 now = current_time(inode); |
1e51764a AB |
1518 | struct ubifs_budget_req req = { .new_page = 1 }; |
1519 | int err, update_time; | |
1520 | ||
1521 | dbg_gen("ino %lu, pg %lu, i_size %lld", inode->i_ino, page->index, | |
1522 | i_size_read(inode)); | |
6eb61d58 | 1523 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
1e51764a | 1524 | |
2680d722 | 1525 | if (unlikely(c->ro_error)) |
c2ec175c | 1526 | return VM_FAULT_SIGBUS; /* -EROFS */ |
1e51764a AB |
1527 | |
1528 | /* | |
1529 | * We have not locked @page so far so we may budget for changing the | |
1530 | * page. Note, we cannot do this after we locked the page, because | |
1531 | * budgeting may cause write-back which would cause deadlock. | |
1532 | * | |
1533 | * At the moment we do not know whether the page is dirty or not, so we | |
1534 | * assume that it is not and budget for a new page. We could look at | |
1535 | * the @PG_private flag and figure this out, but we may race with write | |
1536 | * back and the page state may change by the time we lock it, so this | |
1537 | * would need additional care. We do not bother with this at the | |
1538 | * moment, although it might be good idea to do. Instead, we allocate | |
1539 | * budget for a new page and amend it later on if the page was in fact | |
1540 | * dirty. | |
1541 | * | |
1542 | * The budgeting-related logic of this function is similar to what we | |
1543 | * do in 'ubifs_write_begin()' and 'ubifs_write_end()'. Glance there | |
1544 | * for more comments. | |
1545 | */ | |
1546 | update_time = mctime_update_needed(inode, &now); | |
1547 | if (update_time) | |
1548 | /* | |
1549 | * We have to change inode time stamp which requires extra | |
1550 | * budgeting. | |
1551 | */ | |
1552 | req.dirtied_ino = 1; | |
1553 | ||
1554 | err = ubifs_budget_space(c, &req); | |
1555 | if (unlikely(err)) { | |
1556 | if (err == -ENOSPC) | |
235c362b | 1557 | ubifs_warn(c, "out of space for mmapped file (inode number %lu)", |
79fda517 | 1558 | inode->i_ino); |
c2ec175c | 1559 | return VM_FAULT_SIGBUS; |
1e51764a AB |
1560 | } |
1561 | ||
1562 | lock_page(page); | |
1563 | if (unlikely(page->mapping != inode->i_mapping || | |
1564 | page_offset(page) > i_size_read(inode))) { | |
1565 | /* Page got truncated out from underneath us */ | |
31c49eac | 1566 | goto sigbus; |
1e51764a AB |
1567 | } |
1568 | ||
1569 | if (PagePrivate(page)) | |
1570 | release_new_page_budget(c); | |
1571 | else { | |
1572 | if (!PageChecked(page)) | |
1573 | ubifs_convert_page_budget(c); | |
1574 | SetPagePrivate(page); | |
1575 | atomic_long_inc(&c->dirty_pg_cnt); | |
1576 | __set_page_dirty_nobuffers(page); | |
1577 | } | |
1578 | ||
1579 | if (update_time) { | |
1580 | int release; | |
1581 | struct ubifs_inode *ui = ubifs_inode(inode); | |
1582 | ||
1583 | mutex_lock(&ui->ui_mutex); | |
607a11ad | 1584 | inode->i_mtime = inode->i_ctime = current_time(inode); |
1e51764a AB |
1585 | release = ui->dirty; |
1586 | mark_inode_dirty_sync(inode); | |
1587 | mutex_unlock(&ui->ui_mutex); | |
1588 | if (release) | |
1589 | ubifs_release_dirty_inode_budget(c, ui); | |
1590 | } | |
1591 | ||
182dcfd6 | 1592 | wait_for_stable_page(page); |
691a7c6f | 1593 | return VM_FAULT_LOCKED; |
1e51764a | 1594 | |
31c49eac | 1595 | sigbus: |
1e51764a AB |
1596 | unlock_page(page); |
1597 | ubifs_release_budget(c, &req); | |
31c49eac | 1598 | return VM_FAULT_SIGBUS; |
1e51764a AB |
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; | |
1610 | ||
1e51764a AB |
1611 | err = generic_file_mmap(file, vma); |
1612 | if (err) | |
1613 | return err; | |
1614 | vma->vm_ops = &ubifs_file_vm_ops; | |
e3d73dea SH |
1615 | |
1616 | if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT)) | |
1617 | file_accessed(file); | |
1618 | ||
1e51764a AB |
1619 | return 0; |
1620 | } | |
1621 | ||
ca7f85be RW |
1622 | static const char *ubifs_get_link(struct dentry *dentry, |
1623 | struct inode *inode, | |
1624 | struct delayed_call *done) | |
1625 | { | |
ca7f85be | 1626 | struct ubifs_inode *ui = ubifs_inode(inode); |
ca7f85be | 1627 | |
81dd76b2 | 1628 | if (!IS_ENCRYPTED(inode)) |
ca7f85be RW |
1629 | return ui->data; |
1630 | ||
1631 | if (!dentry) | |
1632 | return ERR_PTR(-ECHILD); | |
1633 | ||
81dd76b2 | 1634 | return fscrypt_get_symlink(inode, ui->data, ui->data_len, done); |
ca7f85be RW |
1635 | } |
1636 | ||
e8b81566 | 1637 | const struct address_space_operations ubifs_file_address_operations = { |
1e51764a AB |
1638 | .readpage = ubifs_readpage, |
1639 | .writepage = ubifs_writepage, | |
1640 | .write_begin = ubifs_write_begin, | |
1641 | .write_end = ubifs_write_end, | |
1642 | .invalidatepage = ubifs_invalidatepage, | |
1643 | .set_page_dirty = ubifs_set_page_dirty, | |
4ac1c17b KS |
1644 | #ifdef CONFIG_MIGRATION |
1645 | .migratepage = ubifs_migrate_page, | |
1646 | #endif | |
1e51764a AB |
1647 | .releasepage = ubifs_releasepage, |
1648 | }; | |
1649 | ||
e8b81566 | 1650 | const struct inode_operations ubifs_file_inode_operations = { |
1e51764a AB |
1651 | .setattr = ubifs_setattr, |
1652 | .getattr = ubifs_getattr, | |
7e5471ce | 1653 | #ifdef CONFIG_UBIFS_FS_XATTR |
1e51764a | 1654 | .listxattr = ubifs_listxattr, |
7e5471ce | 1655 | #endif |
8c1c5f26 | 1656 | .update_time = ubifs_update_time, |
1e51764a AB |
1657 | }; |
1658 | ||
e8b81566 | 1659 | const struct inode_operations ubifs_symlink_inode_operations = { |
ca7f85be | 1660 | .get_link = ubifs_get_link, |
1e51764a AB |
1661 | .setattr = ubifs_setattr, |
1662 | .getattr = ubifs_getattr, | |
7e5471ce | 1663 | #ifdef CONFIG_UBIFS_FS_XATTR |
895d9db2 | 1664 | .listxattr = ubifs_listxattr, |
7e5471ce | 1665 | #endif |
8c1c5f26 | 1666 | .update_time = ubifs_update_time, |
1e51764a AB |
1667 | }; |
1668 | ||
e8b81566 | 1669 | const struct file_operations ubifs_file_operations = { |
1e51764a | 1670 | .llseek = generic_file_llseek, |
aad4f8bb | 1671 | .read_iter = generic_file_read_iter, |
f5674c31 | 1672 | .write_iter = ubifs_write_iter, |
1e51764a AB |
1673 | .mmap = ubifs_file_mmap, |
1674 | .fsync = ubifs_fsync, | |
1675 | .unlocked_ioctl = ubifs_ioctl, | |
1676 | .splice_read = generic_file_splice_read, | |
8d020765 | 1677 | .splice_write = iter_file_splice_write, |
7e35c4da | 1678 | .open = fscrypt_file_open, |
1e51764a AB |
1679 | #ifdef CONFIG_COMPAT |
1680 | .compat_ioctl = ubifs_compat_ioctl, | |
1681 | #endif | |
1682 | }; |