blob: 7bbf420d128988470b0fb90491f05587b83b9052 [file] [log] [blame]
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/*
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/*
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030024 * This file implements VFS file and inode operations for regular files, device
Artem Bityutskiy1e517642008-07-14 19:08:37 +030025 * nodes and symlinks as well as address space operations.
26 *
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030027 * 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.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030037 *
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030038 * 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
Artem Bityutskiy5c57f202012-07-25 18:12:14 +030040 * 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.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030045 *
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030046 * 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 ->
Christoph Hellwigeaff8072009-12-17 14:25:01 +010048 * ondemand_readahead -> readpage"). In case of readahead, @I_SYNC flag is not
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030049 * set as well. However, UBIFS disables readahead.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030050 */
51
52#include "ubifs.h"
53#include <linux/mount.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090054#include <linux/slab.h>
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +020055#include <linux/migrate.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030056
57static 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
Artem Bityutskiyf92b9822008-12-28 11:34:26 +020074 ubifs_assert(le64_to_cpu(dn->ch.sqnum) >
75 ubifs_inode(inode)->creat_sqnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +030076 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;
81 out_len = UBIFS_BLOCK_SIZE;
Sheng Yong235c3622015-03-20 10:39:42 +000082 err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
Artem Bityutskiy1e517642008-07-14 19:08:37 +030083 le16_to_cpu(dn->compr_type));
84 if (err || len != out_len)
85 goto dump;
86
87 /*
88 * Data length can be less than a full block, even for blocks that are
89 * not the last in the file (e.g., as a result of making a hole and
90 * appending data). Ensure that the remainder is zeroed out.
91 */
92 if (len < UBIFS_BLOCK_SIZE)
93 memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
94
95 return 0;
96
97dump:
Sheng Yong235c3622015-03-20 10:39:42 +000098 ubifs_err(c, "bad data node (block %u, inode %lu)",
Artem Bityutskiy1e517642008-07-14 19:08:37 +030099 block, inode->i_ino);
Artem Bityutskiyedf6be22012-05-16 19:15:56 +0300100 ubifs_dump_node(c, dn);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300101 return -EINVAL;
102}
103
104static int do_readpage(struct page *page)
105{
106 void *addr;
107 int err = 0, i;
108 unsigned int block, beyond;
109 struct ubifs_data_node *dn;
110 struct inode *inode = page->mapping->host;
111 loff_t i_size = i_size_read(inode);
112
113 dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
114 inode->i_ino, page->index, i_size, page->flags);
115 ubifs_assert(!PageChecked(page));
116 ubifs_assert(!PagePrivate(page));
117
118 addr = kmap(page);
119
120 block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
121 beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
122 if (block >= beyond) {
123 /* Reading beyond inode */
124 SetPageChecked(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300125 memset(addr, 0, PAGE_SIZE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300126 goto out;
127 }
128
129 dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
130 if (!dn) {
131 err = -ENOMEM;
132 goto error;
133 }
134
135 i = 0;
136 while (1) {
137 int ret;
138
139 if (block >= beyond) {
140 /* Reading beyond inode */
141 err = -ENOENT;
142 memset(addr, 0, UBIFS_BLOCK_SIZE);
143 } else {
144 ret = read_block(inode, addr, block, dn);
145 if (ret) {
146 err = ret;
147 if (err != -ENOENT)
148 break;
Adrian Huntered382d52008-09-05 16:17:42 +0300149 } else if (block + 1 == beyond) {
150 int dlen = le32_to_cpu(dn->size);
151 int ilen = i_size & (UBIFS_BLOCK_SIZE - 1);
152
153 if (ilen && ilen < dlen)
154 memset(addr + ilen, 0, dlen - ilen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300155 }
156 }
157 if (++i >= UBIFS_BLOCKS_PER_PAGE)
158 break;
159 block += 1;
160 addr += UBIFS_BLOCK_SIZE;
161 }
162 if (err) {
Sheng Yong235c3622015-03-20 10:39:42 +0000163 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300164 if (err == -ENOENT) {
165 /* Not found, so it must be a hole */
166 SetPageChecked(page);
167 dbg_gen("hole");
168 goto out_free;
169 }
Sheng Yong235c3622015-03-20 10:39:42 +0000170 ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300171 page->index, inode->i_ino, err);
172 goto error;
173 }
174
175out_free:
176 kfree(dn);
177out:
178 SetPageUptodate(page);
179 ClearPageError(page);
180 flush_dcache_page(page);
181 kunmap(page);
182 return 0;
183
184error:
185 kfree(dn);
186 ClearPageUptodate(page);
187 SetPageError(page);
188 flush_dcache_page(page);
189 kunmap(page);
190 return err;
191}
192
193/**
194 * release_new_page_budget - release budget of a new page.
195 * @c: UBIFS file-system description object
196 *
197 * This is a helper function which releases budget corresponding to the budget
198 * of one new page of data.
199 */
200static void release_new_page_budget(struct ubifs_info *c)
201{
202 struct ubifs_budget_req req = { .recalculate = 1, .new_page = 1 };
203
204 ubifs_release_budget(c, &req);
205}
206
207/**
208 * release_existing_page_budget - release budget of an existing page.
209 * @c: UBIFS file-system description object
210 *
211 * This is a helper function which releases budget corresponding to the budget
212 * of changing one one page of data which already exists on the flash media.
213 */
214static void release_existing_page_budget(struct ubifs_info *c)
215{
Artem Bityutskiyb1375452011-03-29 18:04:05 +0300216 struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget};
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300217
218 ubifs_release_budget(c, &req);
219}
220
221static int write_begin_slow(struct address_space *mapping,
Nick Piggin54566b22009-01-04 12:00:53 -0800222 loff_t pos, unsigned len, struct page **pagep,
223 unsigned flags)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300224{
225 struct inode *inode = mapping->host;
226 struct ubifs_info *c = inode->i_sb->s_fs_info;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300227 pgoff_t index = pos >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300228 struct ubifs_budget_req req = { .new_page = 1 };
229 int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
230 struct page *page;
231
232 dbg_gen("ino %lu, pos %llu, len %u, i_size %lld",
233 inode->i_ino, pos, len, inode->i_size);
234
235 /*
236 * At the slow path we have to budget before locking the page, because
237 * budgeting may force write-back, which would wait on locked pages and
238 * deadlock if we had the page locked. At this point we do not know
239 * anything about the page, so assume that this is a new page which is
240 * written to a hole. This corresponds to largest budget. Later the
241 * budget will be amended if this is not true.
242 */
243 if (appending)
244 /* We are appending data, budget for inode change */
245 req.dirtied_ino = 1;
246
247 err = ubifs_budget_space(c, &req);
248 if (unlikely(err))
249 return err;
250
Nick Piggin54566b22009-01-04 12:00:53 -0800251 page = grab_cache_page_write_begin(mapping, index, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300252 if (unlikely(!page)) {
253 ubifs_release_budget(c, &req);
254 return -ENOMEM;
255 }
256
257 if (!PageUptodate(page)) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300258 if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300259 SetPageChecked(page);
260 else {
261 err = do_readpage(page);
262 if (err) {
263 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300264 put_page(page);
Artem Bityutskiy789c8992014-10-20 17:52:31 +0300265 ubifs_release_budget(c, &req);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300266 return err;
267 }
268 }
269
270 SetPageUptodate(page);
271 ClearPageError(page);
272 }
273
274 if (PagePrivate(page))
275 /*
276 * The page is dirty, which means it was budgeted twice:
277 * o first time the budget was allocated by the task which
278 * made the page dirty and set the PG_private flag;
279 * o and then we budgeted for it for the second time at the
280 * very beginning of this function.
281 *
282 * So what we have to do is to release the page budget we
283 * allocated.
284 */
285 release_new_page_budget(c);
286 else if (!PageChecked(page))
287 /*
288 * We are changing a page which already exists on the media.
289 * This means that changing the page does not make the amount
290 * of indexing information larger, and this part of the budget
291 * which we have already acquired may be released.
292 */
293 ubifs_convert_page_budget(c);
294
295 if (appending) {
296 struct ubifs_inode *ui = ubifs_inode(inode);
297
298 /*
299 * 'ubifs_write_end()' is optimized from the fast-path part of
300 * 'ubifs_write_begin()' and expects the @ui_mutex to be locked
301 * if data is appended.
302 */
303 mutex_lock(&ui->ui_mutex);
304 if (ui->dirty)
305 /*
306 * The inode is dirty already, so we may free the
307 * budget we allocated.
308 */
309 ubifs_release_dirty_inode_budget(c, ui);
310 }
311
312 *pagep = page;
313 return 0;
314}
315
316/**
317 * allocate_budget - allocate budget for 'ubifs_write_begin()'.
318 * @c: UBIFS file-system description object
319 * @page: page to allocate budget for
320 * @ui: UBIFS inode object the page belongs to
321 * @appending: non-zero if the page is appended
322 *
323 * This is a helper function for 'ubifs_write_begin()' which allocates budget
324 * for the operation. The budget is allocated differently depending on whether
325 * this is appending, whether the page is dirty or not, and so on. This
326 * function leaves the @ui->ui_mutex locked in case of appending. Returns zero
327 * in case of success and %-ENOSPC in case of failure.
328 */
329static int allocate_budget(struct ubifs_info *c, struct page *page,
330 struct ubifs_inode *ui, int appending)
331{
332 struct ubifs_budget_req req = { .fast = 1 };
333
334 if (PagePrivate(page)) {
335 if (!appending)
336 /*
337 * The page is dirty and we are not appending, which
338 * means no budget is needed at all.
339 */
340 return 0;
341
342 mutex_lock(&ui->ui_mutex);
343 if (ui->dirty)
344 /*
345 * The page is dirty and we are appending, so the inode
346 * has to be marked as dirty. However, it is already
347 * dirty, so we do not need any budget. We may return,
348 * but @ui->ui_mutex hast to be left locked because we
349 * should prevent write-back from flushing the inode
350 * and freeing the budget. The lock will be released in
351 * 'ubifs_write_end()'.
352 */
353 return 0;
354
355 /*
356 * The page is dirty, we are appending, the inode is clean, so
357 * we need to budget the inode change.
358 */
359 req.dirtied_ino = 1;
360 } else {
361 if (PageChecked(page))
362 /*
363 * The page corresponds to a hole and does not
364 * exist on the media. So changing it makes
365 * make the amount of indexing information
366 * larger, and we have to budget for a new
367 * page.
368 */
369 req.new_page = 1;
370 else
371 /*
372 * Not a hole, the change will not add any new
373 * indexing information, budget for page
374 * change.
375 */
376 req.dirtied_page = 1;
377
378 if (appending) {
379 mutex_lock(&ui->ui_mutex);
380 if (!ui->dirty)
381 /*
382 * The inode is clean but we will have to mark
383 * it as dirty because we are appending. This
384 * needs a budget.
385 */
386 req.dirtied_ino = 1;
387 }
388 }
389
390 return ubifs_budget_space(c, &req);
391}
392
393/*
394 * This function is called when a page of data is going to be written. Since
395 * the page of data will not necessarily go to the flash straight away, UBIFS
396 * has to reserve space on the media for it, which is done by means of
397 * budgeting.
398 *
399 * This is the hot-path of the file-system and we are trying to optimize it as
400 * much as possible. For this reasons it is split on 2 parts - slow and fast.
401 *
402 * There many budgeting cases:
403 * o a new page is appended - we have to budget for a new page and for
404 * changing the inode; however, if the inode is already dirty, there is
405 * no need to budget for it;
406 * o an existing clean page is changed - we have budget for it; if the page
407 * does not exist on the media (a hole), we have to budget for a new
408 * page; otherwise, we may budget for changing an existing page; the
409 * difference between these cases is that changing an existing page does
410 * not introduce anything new to the FS indexing information, so it does
411 * not grow, and smaller budget is acquired in this case;
412 * o an existing dirty page is changed - no need to budget at all, because
413 * the page budget has been acquired by earlier, when the page has been
414 * marked dirty.
415 *
416 * UBIFS budgeting sub-system may force write-back if it thinks there is no
417 * space to reserve. This imposes some locking restrictions and makes it
418 * impossible to take into account the above cases, and makes it impossible to
419 * optimize budgeting.
420 *
421 * The solution for this is that the fast path of 'ubifs_write_begin()' assumes
422 * there is a plenty of flash space and the budget will be acquired quickly,
423 * without forcing write-back. The slow path does not make this assumption.
424 */
425static int ubifs_write_begin(struct file *file, struct address_space *mapping,
426 loff_t pos, unsigned len, unsigned flags,
427 struct page **pagep, void **fsdata)
428{
429 struct inode *inode = mapping->host;
430 struct ubifs_info *c = inode->i_sb->s_fs_info;
431 struct ubifs_inode *ui = ubifs_inode(inode);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300432 pgoff_t index = pos >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300433 int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
Adrian Hunterf55aa592009-02-23 12:47:25 +0200434 int skipped_read = 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300435 struct page *page;
436
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300437 ubifs_assert(ubifs_inode(inode)->ui_size == inode->i_size);
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300438 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300439
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300440 if (unlikely(c->ro_error))
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300441 return -EROFS;
442
443 /* Try out the fast-path part first */
Nick Piggin54566b22009-01-04 12:00:53 -0800444 page = grab_cache_page_write_begin(mapping, index, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300445 if (unlikely(!page))
446 return -ENOMEM;
447
448 if (!PageUptodate(page)) {
449 /* The page is not loaded from the flash */
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300450 if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300451 /*
452 * We change whole page so no need to load it. But we
Artem Bityutskiy6ed09c32011-03-23 10:32:58 +0200453 * do not know whether this page exists on the media or
454 * not, so we assume the latter because it requires
455 * larger budget. The assumption is that it is better
456 * to budget a bit more than to read the page from the
457 * media. Thus, we are setting the @PG_checked flag
458 * here.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300459 */
460 SetPageChecked(page);
Adrian Hunterf55aa592009-02-23 12:47:25 +0200461 skipped_read = 1;
462 } else {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300463 err = do_readpage(page);
464 if (err) {
465 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300466 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300467 return err;
468 }
469 }
470
471 SetPageUptodate(page);
472 ClearPageError(page);
473 }
474
475 err = allocate_budget(c, page, ui, appending);
476 if (unlikely(err)) {
477 ubifs_assert(err == -ENOSPC);
478 /*
Adrian Hunterf55aa592009-02-23 12:47:25 +0200479 * If we skipped reading the page because we were going to
480 * write all of it, then it is not up to date.
481 */
482 if (skipped_read) {
483 ClearPageChecked(page);
484 ClearPageUptodate(page);
485 }
486 /*
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300487 * Budgeting failed which means it would have to force
488 * write-back but didn't, because we set the @fast flag in the
489 * request. Write-back cannot be done now, while we have the
490 * page locked, because it would deadlock. Unlock and free
491 * everything and fall-back to slow-path.
492 */
493 if (appending) {
494 ubifs_assert(mutex_is_locked(&ui->ui_mutex));
495 mutex_unlock(&ui->ui_mutex);
496 }
497 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300498 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300499
Nick Piggin54566b22009-01-04 12:00:53 -0800500 return write_begin_slow(mapping, pos, len, pagep, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300501 }
502
503 /*
Artem Bityutskiy873a64c2009-09-01 17:06:43 +0300504 * Whee, we acquired budgeting quickly - without involving
505 * garbage-collection, committing or forcing write-back. We return
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300506 * with @ui->ui_mutex locked if we are appending pages, and unlocked
507 * otherwise. This is an optimization (slightly hacky though).
508 */
509 *pagep = page;
510 return 0;
511
512}
513
514/**
515 * cancel_budget - cancel budget.
516 * @c: UBIFS file-system description object
517 * @page: page to cancel budget for
518 * @ui: UBIFS inode object the page belongs to
519 * @appending: non-zero if the page is appended
520 *
521 * This is a helper function for a page write operation. It unlocks the
522 * @ui->ui_mutex in case of appending.
523 */
524static void cancel_budget(struct ubifs_info *c, struct page *page,
525 struct ubifs_inode *ui, int appending)
526{
527 if (appending) {
528 if (!ui->dirty)
529 ubifs_release_dirty_inode_budget(c, ui);
530 mutex_unlock(&ui->ui_mutex);
531 }
532 if (!PagePrivate(page)) {
533 if (PageChecked(page))
534 release_new_page_budget(c);
535 else
536 release_existing_page_budget(c);
537 }
538}
539
540static int ubifs_write_end(struct file *file, struct address_space *mapping,
541 loff_t pos, unsigned len, unsigned copied,
542 struct page *page, void *fsdata)
543{
544 struct inode *inode = mapping->host;
545 struct ubifs_inode *ui = ubifs_inode(inode);
546 struct ubifs_info *c = inode->i_sb->s_fs_info;
547 loff_t end_pos = pos + len;
548 int appending = !!(end_pos > inode->i_size);
549
550 dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld",
551 inode->i_ino, pos, page->index, len, copied, inode->i_size);
552
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300553 if (unlikely(copied < len && len == PAGE_SIZE)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300554 /*
555 * VFS copied less data to the page that it intended and
556 * declared in its '->write_begin()' call via the @len
557 * argument. If the page was not up-to-date, and @len was
Kirill A. Shutemovea1754a2016-04-01 15:29:48 +0300558 * @PAGE_SIZE, the 'ubifs_write_begin()' function did
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300559 * not load it from the media (for optimization reasons). This
560 * means that part of the page contains garbage. So read the
561 * page now.
562 */
563 dbg_gen("copied %d instead of %d, read page and repeat",
564 copied, len);
565 cancel_budget(c, page, ui, appending);
Artem Bityutskiy6ed09c32011-03-23 10:32:58 +0200566 ClearPageChecked(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300567
568 /*
569 * Return 0 to force VFS to repeat the whole operation, or the
Artem Bityutskiy873a64c2009-09-01 17:06:43 +0300570 * error code if 'do_readpage()' fails.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300571 */
572 copied = do_readpage(page);
573 goto out;
574 }
575
576 if (!PagePrivate(page)) {
577 SetPagePrivate(page);
578 atomic_long_inc(&c->dirty_pg_cnt);
579 __set_page_dirty_nobuffers(page);
580 }
581
582 if (appending) {
583 i_size_write(inode, end_pos);
584 ui->ui_size = end_pos;
585 /*
586 * Note, we do not set @I_DIRTY_PAGES (which means that the
587 * inode has dirty pages), this has been done in
588 * '__set_page_dirty_nobuffers()'.
589 */
590 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
591 ubifs_assert(mutex_is_locked(&ui->ui_mutex));
592 mutex_unlock(&ui->ui_mutex);
593 }
594
595out:
596 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300597 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300598 return copied;
599}
600
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300601/**
602 * populate_page - copy data nodes into a page for bulk-read.
603 * @c: UBIFS file-system description object
604 * @page: page
605 * @bu: bulk-read information
606 * @n: next zbranch slot
607 *
608 * This function returns %0 on success and a negative error code on failure.
609 */
610static int populate_page(struct ubifs_info *c, struct page *page,
611 struct bu_info *bu, int *n)
612{
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300613 int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300614 struct inode *inode = page->mapping->host;
615 loff_t i_size = i_size_read(inode);
616 unsigned int page_block;
617 void *addr, *zaddr;
618 pgoff_t end_index;
619
620 dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
621 inode->i_ino, page->index, i_size, page->flags);
622
623 addr = zaddr = kmap(page);
624
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300625 end_index = (i_size - 1) >> PAGE_SHIFT;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300626 if (!i_size || page->index > end_index) {
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300627 hole = 1;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300628 memset(addr, 0, PAGE_SIZE);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300629 goto out_hole;
630 }
631
632 page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
633 while (1) {
634 int err, len, out_len, dlen;
635
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300636 if (nn >= bu->cnt) {
637 hole = 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300638 memset(addr, 0, UBIFS_BLOCK_SIZE);
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300639 } else if (key_block(c, &bu->zbranch[nn].key) == page_block) {
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300640 struct ubifs_data_node *dn;
641
642 dn = bu->buf + (bu->zbranch[nn].offs - offs);
643
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700644 ubifs_assert(le64_to_cpu(dn->ch.sqnum) >
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300645 ubifs_inode(inode)->creat_sqnum);
646
647 len = le32_to_cpu(dn->size);
648 if (len <= 0 || len > UBIFS_BLOCK_SIZE)
649 goto out_err;
650
651 dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
652 out_len = UBIFS_BLOCK_SIZE;
Sheng Yong235c3622015-03-20 10:39:42 +0000653 err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300654 le16_to_cpu(dn->compr_type));
655 if (err || len != out_len)
656 goto out_err;
657
658 if (len < UBIFS_BLOCK_SIZE)
659 memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
660
661 nn += 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300662 read = (i << UBIFS_BLOCK_SHIFT) + len;
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300663 } else if (key_block(c, &bu->zbranch[nn].key) < page_block) {
664 nn += 1;
665 continue;
666 } else {
667 hole = 1;
668 memset(addr, 0, UBIFS_BLOCK_SIZE);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300669 }
670 if (++i >= UBIFS_BLOCKS_PER_PAGE)
671 break;
672 addr += UBIFS_BLOCK_SIZE;
673 page_block += 1;
674 }
675
676 if (end_index == page->index) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300677 int len = i_size & (PAGE_SIZE - 1);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300678
Adrian Huntered382d52008-09-05 16:17:42 +0300679 if (len && len < read)
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300680 memset(zaddr + len, 0, read - len);
681 }
682
683out_hole:
684 if (hole) {
685 SetPageChecked(page);
686 dbg_gen("hole");
687 }
688
689 SetPageUptodate(page);
690 ClearPageError(page);
691 flush_dcache_page(page);
692 kunmap(page);
693 *n = nn;
694 return 0;
695
696out_err:
697 ClearPageUptodate(page);
698 SetPageError(page);
699 flush_dcache_page(page);
700 kunmap(page);
Sheng Yong235c3622015-03-20 10:39:42 +0000701 ubifs_err(c, "bad data node (block %u, inode %lu)",
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300702 page_block, inode->i_ino);
703 return -EINVAL;
704}
705
706/**
707 * ubifs_do_bulk_read - do bulk-read.
708 * @c: UBIFS file-system description object
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200709 * @bu: bulk-read information
710 * @page1: first page to read
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300711 *
712 * This function returns %1 if the bulk-read is done, otherwise %0 is returned.
713 */
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200714static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu,
715 struct page *page1)
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300716{
717 pgoff_t offset = page1->index, end_index;
718 struct address_space *mapping = page1->mapping;
719 struct inode *inode = mapping->host;
720 struct ubifs_inode *ui = ubifs_inode(inode);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300721 int err, page_idx, page_cnt, ret = 0, n = 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200722 int allocate = bu->buf ? 0 : 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300723 loff_t isize;
724
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300725 err = ubifs_tnc_get_bu_keys(c, bu);
726 if (err)
727 goto out_warn;
728
729 if (bu->eof) {
730 /* Turn off bulk-read at the end of the file */
731 ui->read_in_a_row = 1;
732 ui->bulk_read = 0;
733 }
734
735 page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT;
736 if (!page_cnt) {
737 /*
738 * This happens when there are multiple blocks per page and the
739 * blocks for the first page we are looking for, are not
740 * together. If all the pages were like this, bulk-read would
741 * reduce performance, so we turn it off for a while.
742 */
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200743 goto out_bu_off;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300744 }
745
746 if (bu->cnt) {
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200747 if (allocate) {
748 /*
749 * Allocate bulk-read buffer depending on how many data
750 * nodes we are going to read.
751 */
752 bu->buf_len = bu->zbranch[bu->cnt - 1].offs +
753 bu->zbranch[bu->cnt - 1].len -
754 bu->zbranch[0].offs;
755 ubifs_assert(bu->buf_len > 0);
756 ubifs_assert(bu->buf_len <= c->leb_size);
757 bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN);
758 if (!bu->buf)
759 goto out_bu_off;
760 }
761
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300762 err = ubifs_tnc_bulk_read(c, bu);
763 if (err)
764 goto out_warn;
765 }
766
767 err = populate_page(c, page1, bu, &n);
768 if (err)
769 goto out_warn;
770
771 unlock_page(page1);
772 ret = 1;
773
774 isize = i_size_read(inode);
775 if (isize == 0)
776 goto out_free;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300777 end_index = ((isize - 1) >> PAGE_SHIFT);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300778
779 for (page_idx = 1; page_idx < page_cnt; page_idx++) {
780 pgoff_t page_offset = offset + page_idx;
781 struct page *page;
782
783 if (page_offset > end_index)
784 break;
785 page = find_or_create_page(mapping, page_offset,
786 GFP_NOFS | __GFP_COLD);
787 if (!page)
788 break;
789 if (!PageUptodate(page))
790 err = populate_page(c, page, bu, &n);
791 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300792 put_page(page);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300793 if (err)
794 break;
795 }
796
797 ui->last_page_read = offset + page_idx - 1;
798
799out_free:
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200800 if (allocate)
801 kfree(bu->buf);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300802 return ret;
803
804out_warn:
Sheng Yong235c3622015-03-20 10:39:42 +0000805 ubifs_warn(c, "ignoring error %d and skipping bulk-read", err);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300806 goto out_free;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200807
808out_bu_off:
809 ui->read_in_a_row = ui->bulk_read = 0;
810 goto out_free;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300811}
812
813/**
814 * ubifs_bulk_read - determine whether to bulk-read and, if so, do it.
815 * @page: page from which to start bulk-read.
816 *
817 * Some flash media are capable of reading sequentially at faster rates. UBIFS
818 * bulk-read facility is designed to take advantage of that, by reading in one
819 * go consecutive data nodes that are also located consecutively in the same
820 * LEB. This function returns %1 if a bulk-read is done and %0 otherwise.
821 */
822static int ubifs_bulk_read(struct page *page)
823{
824 struct inode *inode = page->mapping->host;
825 struct ubifs_info *c = inode->i_sb->s_fs_info;
826 struct ubifs_inode *ui = ubifs_inode(inode);
827 pgoff_t index = page->index, last_page_read = ui->last_page_read;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200828 struct bu_info *bu;
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200829 int err = 0, allocated = 0;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300830
831 ui->last_page_read = index;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300832 if (!c->bulk_read)
833 return 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200834
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300835 /*
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200836 * Bulk-read is protected by @ui->ui_mutex, but it is an optimization,
837 * so don't bother if we cannot lock the mutex.
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300838 */
839 if (!mutex_trylock(&ui->ui_mutex))
840 return 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200841
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300842 if (index != last_page_read + 1) {
843 /* Turn off bulk-read if we stop reading sequentially */
844 ui->read_in_a_row = 1;
845 if (ui->bulk_read)
846 ui->bulk_read = 0;
847 goto out_unlock;
848 }
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200849
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300850 if (!ui->bulk_read) {
851 ui->read_in_a_row += 1;
852 if (ui->read_in_a_row < 3)
853 goto out_unlock;
854 /* Three reads in a row, so switch on bulk-read */
855 ui->bulk_read = 1;
856 }
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200857
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200858 /*
859 * If possible, try to use pre-allocated bulk-read information, which
860 * is protected by @c->bu_mutex.
861 */
862 if (mutex_trylock(&c->bu_mutex))
863 bu = &c->bu;
864 else {
865 bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN);
866 if (!bu)
867 goto out_unlock;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200868
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200869 bu->buf = NULL;
870 allocated = 1;
871 }
872
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200873 bu->buf_len = c->max_bu_buf_len;
874 data_key_init(c, &bu->key, inode->i_ino,
875 page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200876 err = ubifs_do_bulk_read(c, bu, page);
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200877
878 if (!allocated)
879 mutex_unlock(&c->bu_mutex);
880 else
881 kfree(bu);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200882
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300883out_unlock:
884 mutex_unlock(&ui->ui_mutex);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200885 return err;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300886}
887
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300888static int ubifs_readpage(struct file *file, struct page *page)
889{
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300890 if (ubifs_bulk_read(page))
891 return 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300892 do_readpage(page);
893 unlock_page(page);
894 return 0;
895}
896
897static int do_writepage(struct page *page, int len)
898{
899 int err = 0, i, blen;
900 unsigned int block;
901 void *addr;
902 union ubifs_key key;
903 struct inode *inode = page->mapping->host;
904 struct ubifs_info *c = inode->i_sb->s_fs_info;
905
906#ifdef UBIFS_DEBUG
Daniel Gollea0fd5952014-05-13 22:27:58 +0200907 struct ubifs_inode *ui = ubifs_inode(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300908 spin_lock(&ui->ui_lock);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300909 ubifs_assert(page->index <= ui->synced_i_size >> PAGE_SHIFT);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300910 spin_unlock(&ui->ui_lock);
911#endif
912
913 /* Update radix tree tags */
914 set_page_writeback(page);
915
916 addr = kmap(page);
917 block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
918 i = 0;
919 while (len) {
920 blen = min_t(int, len, UBIFS_BLOCK_SIZE);
921 data_key_init(c, &key, inode->i_ino, block);
922 err = ubifs_jnl_write_data(c, inode, &key, addr, blen);
923 if (err)
924 break;
925 if (++i >= UBIFS_BLOCKS_PER_PAGE)
926 break;
927 block += 1;
928 addr += blen;
929 len -= blen;
930 }
931 if (err) {
932 SetPageError(page);
Sheng Yong235c3622015-03-20 10:39:42 +0000933 ubifs_err(c, "cannot write page %lu of inode %lu, error %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300934 page->index, inode->i_ino, err);
935 ubifs_ro_mode(c, err);
936 }
937
938 ubifs_assert(PagePrivate(page));
939 if (PageChecked(page))
940 release_new_page_budget(c);
941 else
942 release_existing_page_budget(c);
943
944 atomic_long_dec(&c->dirty_pg_cnt);
945 ClearPagePrivate(page);
946 ClearPageChecked(page);
947
948 kunmap(page);
949 unlock_page(page);
950 end_page_writeback(page);
951 return err;
952}
953
954/*
955 * When writing-back dirty inodes, VFS first writes-back pages belonging to the
956 * inode, then the inode itself. For UBIFS this may cause a problem. Consider a
957 * situation when a we have an inode with size 0, then a megabyte of data is
958 * appended to the inode, then write-back starts and flushes some amount of the
959 * dirty pages, the journal becomes full, commit happens and finishes, and then
960 * an unclean reboot happens. When the file system is mounted next time, the
961 * inode size would still be 0, but there would be many pages which are beyond
962 * the inode size, they would be indexed and consume flash space. Because the
963 * journal has been committed, the replay would not be able to detect this
964 * situation and correct the inode size. This means UBIFS would have to scan
965 * whole index and correct all inode sizes, which is long an unacceptable.
966 *
967 * To prevent situations like this, UBIFS writes pages back only if they are
Artem Bityutskiy7d4e9cc2009-03-20 19:11:12 +0200968 * within the last synchronized inode size, i.e. the size which has been
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300969 * written to the flash media last time. Otherwise, UBIFS forces inode
970 * write-back, thus making sure the on-flash inode contains current inode size,
971 * and then keeps writing pages back.
972 *
973 * Some locking issues explanation. 'ubifs_writepage()' first is called with
974 * the page locked, and it locks @ui_mutex. However, write-back does take inode
975 * @i_mutex, which means other VFS operations may be run on this inode at the
976 * same time. And the problematic one is truncation to smaller size, from where
Artem Bityutskiyc4361572011-03-25 15:27:40 +0200977 * we have to call 'truncate_setsize()', which first changes @inode->i_size,
978 * then drops the truncated pages. And while dropping the pages, it takes the
979 * page lock. This means that 'do_truncation()' cannot call 'truncate_setsize()'
980 * with @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'.
981 * This means that @inode->i_size is changed while @ui_mutex is unlocked.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300982 *
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200983 * XXX(truncate): with the new truncate sequence this is not true anymore,
984 * and the calls to truncate_setsize can be move around freely. They should
985 * be moved to the very end of the truncate sequence.
npiggin@suse.de15c6fd92010-05-27 01:05:34 +1000986 *
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300987 * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond
988 * inode size. How do we do this if @inode->i_size may became smaller while we
989 * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the
990 * @ui->ui_isize "shadow" field which UBIFS uses instead of @inode->i_size
991 * internally and updates it under @ui_mutex.
992 *
993 * Q: why we do not worry that if we race with truncation, we may end up with a
994 * situation when the inode is truncated while we are in the middle of
995 * 'do_writepage()', so we do write beyond inode size?
996 * A: If we are in the middle of 'do_writepage()', truncation would be locked
997 * on the page lock and it would not write the truncated inode node to the
998 * journal before we have finished.
999 */
1000static int ubifs_writepage(struct page *page, struct writeback_control *wbc)
1001{
1002 struct inode *inode = page->mapping->host;
1003 struct ubifs_inode *ui = ubifs_inode(inode);
1004 loff_t i_size = i_size_read(inode), synced_i_size;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001005 pgoff_t end_index = i_size >> PAGE_SHIFT;
1006 int err, len = i_size & (PAGE_SIZE - 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001007 void *kaddr;
1008
1009 dbg_gen("ino %lu, pg %lu, pg flags %#lx",
1010 inode->i_ino, page->index, page->flags);
1011 ubifs_assert(PagePrivate(page));
1012
1013 /* Is the page fully outside @i_size? (truncate in progress) */
1014 if (page->index > end_index || (page->index == end_index && !len)) {
1015 err = 0;
1016 goto out_unlock;
1017 }
1018
1019 spin_lock(&ui->ui_lock);
1020 synced_i_size = ui->synced_i_size;
1021 spin_unlock(&ui->ui_lock);
1022
1023 /* Is the page fully inside @i_size? */
1024 if (page->index < end_index) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001025 if (page->index >= synced_i_size >> PAGE_SHIFT) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001026 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001027 if (err)
1028 goto out_unlock;
1029 /*
1030 * The inode has been written, but the write-buffer has
1031 * not been synchronized, so in case of an unclean
1032 * reboot we may end up with some pages beyond inode
1033 * size, but they would be in the journal (because
1034 * commit flushes write buffers) and recovery would deal
1035 * with this.
1036 */
1037 }
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001038 return do_writepage(page, PAGE_SIZE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001039 }
1040
1041 /*
1042 * The page straddles @i_size. It must be zeroed out on each and every
1043 * writepage invocation because it may be mmapped. "A file is mapped
1044 * in multiples of the page size. For a file that is not a multiple of
1045 * the page size, the remaining memory is zeroed when mapped, and
1046 * writes to that region are not written out to the file."
1047 */
Cong Wanga1c7c1372011-11-25 23:14:36 +08001048 kaddr = kmap_atomic(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001049 memset(kaddr + len, 0, PAGE_SIZE - len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001050 flush_dcache_page(page);
Cong Wanga1c7c1372011-11-25 23:14:36 +08001051 kunmap_atomic(kaddr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001052
1053 if (i_size > synced_i_size) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001054 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001055 if (err)
1056 goto out_unlock;
1057 }
1058
1059 return do_writepage(page, len);
1060
1061out_unlock:
1062 unlock_page(page);
1063 return err;
1064}
1065
1066/**
1067 * do_attr_changes - change inode attributes.
1068 * @inode: inode to change attributes for
1069 * @attr: describes attributes to change
1070 */
1071static void do_attr_changes(struct inode *inode, const struct iattr *attr)
1072{
1073 if (attr->ia_valid & ATTR_UID)
1074 inode->i_uid = attr->ia_uid;
1075 if (attr->ia_valid & ATTR_GID)
1076 inode->i_gid = attr->ia_gid;
1077 if (attr->ia_valid & ATTR_ATIME)
1078 inode->i_atime = timespec_trunc(attr->ia_atime,
1079 inode->i_sb->s_time_gran);
1080 if (attr->ia_valid & ATTR_MTIME)
1081 inode->i_mtime = timespec_trunc(attr->ia_mtime,
1082 inode->i_sb->s_time_gran);
1083 if (attr->ia_valid & ATTR_CTIME)
1084 inode->i_ctime = timespec_trunc(attr->ia_ctime,
1085 inode->i_sb->s_time_gran);
1086 if (attr->ia_valid & ATTR_MODE) {
1087 umode_t mode = attr->ia_mode;
1088
1089 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
1090 mode &= ~S_ISGID;
1091 inode->i_mode = mode;
1092 }
1093}
1094
1095/**
1096 * do_truncation - truncate an inode.
1097 * @c: UBIFS file-system description object
1098 * @inode: inode to truncate
1099 * @attr: inode attribute changes description
1100 *
1101 * This function implements VFS '->setattr()' call when the inode is truncated
1102 * to a smaller size. Returns zero in case of success and a negative error code
1103 * in case of failure.
1104 */
1105static int do_truncation(struct ubifs_info *c, struct inode *inode,
1106 const struct iattr *attr)
1107{
1108 int err;
1109 struct ubifs_budget_req req;
1110 loff_t old_size = inode->i_size, new_size = attr->ia_size;
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001111 int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001112 struct ubifs_inode *ui = ubifs_inode(inode);
1113
1114 dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size);
1115 memset(&req, 0, sizeof(struct ubifs_budget_req));
1116
1117 /*
1118 * If this is truncation to a smaller size, and we do not truncate on a
1119 * block boundary, budget for changing one data block, because the last
1120 * block will be re-written.
1121 */
1122 if (new_size & (UBIFS_BLOCK_SIZE - 1))
1123 req.dirtied_page = 1;
1124
1125 req.dirtied_ino = 1;
1126 /* A funny way to budget for truncation node */
1127 req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ;
1128 err = ubifs_budget_space(c, &req);
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001129 if (err) {
1130 /*
1131 * Treat truncations to zero as deletion and always allow them,
1132 * just like we do for '->unlink()'.
1133 */
1134 if (new_size || err != -ENOSPC)
1135 return err;
1136 budgeted = 0;
1137 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001138
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001139 truncate_setsize(inode, new_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001140
1141 if (offset) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001142 pgoff_t index = new_size >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001143 struct page *page;
1144
1145 page = find_lock_page(inode->i_mapping, index);
1146 if (page) {
1147 if (PageDirty(page)) {
1148 /*
1149 * 'ubifs_jnl_truncate()' will try to truncate
1150 * the last data node, but it contains
1151 * out-of-date data because the page is dirty.
1152 * Write the page now, so that
1153 * 'ubifs_jnl_truncate()' will see an already
1154 * truncated (and up to date) data node.
1155 */
1156 ubifs_assert(PagePrivate(page));
1157
1158 clear_page_dirty_for_io(page);
1159 if (UBIFS_BLOCKS_PER_PAGE_SHIFT)
1160 offset = new_size &
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001161 (PAGE_SIZE - 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001162 err = do_writepage(page, offset);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001163 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001164 if (err)
1165 goto out_budg;
1166 /*
1167 * We could now tell 'ubifs_jnl_truncate()' not
1168 * to read the last block.
1169 */
1170 } else {
1171 /*
1172 * We could 'kmap()' the page and pass the data
1173 * to 'ubifs_jnl_truncate()' to save it from
1174 * having to read it.
1175 */
1176 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001177 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001178 }
1179 }
1180 }
1181
1182 mutex_lock(&ui->ui_mutex);
1183 ui->ui_size = inode->i_size;
1184 /* Truncation changes inode [mc]time */
1185 inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
Artem Bityutskiy873a64c2009-09-01 17:06:43 +03001186 /* Other attributes may be changed at the same time as well */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001187 do_attr_changes(inode, attr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001188 err = ubifs_jnl_truncate(c, inode, old_size, new_size);
1189 mutex_unlock(&ui->ui_mutex);
Artem Bityutskiy873a64c2009-09-01 17:06:43 +03001190
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001191out_budg:
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001192 if (budgeted)
1193 ubifs_release_budget(c, &req);
1194 else {
Artem Bityutskiyb1375452011-03-29 18:04:05 +03001195 c->bi.nospace = c->bi.nospace_rp = 0;
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001196 smp_wmb();
1197 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001198 return err;
1199}
1200
1201/**
1202 * do_setattr - change inode attributes.
1203 * @c: UBIFS file-system description object
1204 * @inode: inode to change attributes for
1205 * @attr: inode attribute changes description
1206 *
1207 * This function implements VFS '->setattr()' call for all cases except
1208 * truncations to smaller size. Returns zero in case of success and a negative
1209 * error code in case of failure.
1210 */
1211static int do_setattr(struct ubifs_info *c, struct inode *inode,
1212 const struct iattr *attr)
1213{
1214 int err, release;
1215 loff_t new_size = attr->ia_size;
1216 struct ubifs_inode *ui = ubifs_inode(inode);
1217 struct ubifs_budget_req req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001218 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001219
1220 err = ubifs_budget_space(c, &req);
1221 if (err)
1222 return err;
1223
1224 if (attr->ia_valid & ATTR_SIZE) {
1225 dbg_gen("size %lld -> %lld", inode->i_size, new_size);
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001226 truncate_setsize(inode, new_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001227 }
1228
1229 mutex_lock(&ui->ui_mutex);
1230 if (attr->ia_valid & ATTR_SIZE) {
1231 /* Truncation changes inode [mc]time */
1232 inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001233 /* 'truncate_setsize()' changed @i_size, update @ui_size */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001234 ui->ui_size = inode->i_size;
1235 }
1236
1237 do_attr_changes(inode, attr);
1238
1239 release = ui->dirty;
1240 if (attr->ia_valid & ATTR_SIZE)
1241 /*
1242 * Inode length changed, so we have to make sure
1243 * @I_DIRTY_DATASYNC is set.
1244 */
1245 __mark_inode_dirty(inode, I_DIRTY_SYNC | I_DIRTY_DATASYNC);
1246 else
1247 mark_inode_dirty_sync(inode);
1248 mutex_unlock(&ui->ui_mutex);
1249
1250 if (release)
1251 ubifs_release_budget(c, &req);
1252 if (IS_SYNC(inode))
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001253 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001254 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001255}
1256
1257int ubifs_setattr(struct dentry *dentry, struct iattr *attr)
1258{
1259 int err;
David Howells2b0143b2015-03-17 22:25:59 +00001260 struct inode *inode = d_inode(dentry);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001261 struct ubifs_info *c = inode->i_sb->s_fs_info;
1262
Artem Bityutskiy7d32c2b2008-07-18 18:54:29 +03001263 dbg_gen("ino %lu, mode %#x, ia_valid %#x",
1264 inode->i_ino, inode->i_mode, attr->ia_valid);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001265 err = inode_change_ok(inode, attr);
1266 if (err)
1267 return err;
1268
Artem Bityutskiyd808efb2011-05-31 18:14:38 +03001269 err = dbg_check_synced_i_size(c, inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001270 if (err)
1271 return err;
1272
1273 if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size < inode->i_size)
1274 /* Truncation to a smaller size */
1275 err = do_truncation(c, inode, attr);
1276 else
1277 err = do_setattr(c, inode, attr);
1278
1279 return err;
1280}
1281
Lukas Czernerd47992f2013-05-21 23:17:23 -04001282static void ubifs_invalidatepage(struct page *page, unsigned int offset,
1283 unsigned int length)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001284{
1285 struct inode *inode = page->mapping->host;
1286 struct ubifs_info *c = inode->i_sb->s_fs_info;
1287
1288 ubifs_assert(PagePrivate(page));
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001289 if (offset || length < PAGE_SIZE)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001290 /* Partial page remains dirty */
1291 return;
1292
1293 if (PageChecked(page))
1294 release_new_page_budget(c);
1295 else
1296 release_existing_page_budget(c);
1297
1298 atomic_long_dec(&c->dirty_pg_cnt);
1299 ClearPagePrivate(page);
1300 ClearPageChecked(page);
1301}
1302
Josef Bacik02c24a82011-07-16 20:44:56 -04001303int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001304{
Christoph Hellwig7ea80852010-05-26 17:53:25 +02001305 struct inode *inode = file->f_mapping->host;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001306 struct ubifs_info *c = inode->i_sb->s_fs_info;
1307 int err;
1308
1309 dbg_gen("syncing inode %lu", inode->i_ino);
1310
Artem Bityutskiy3b2f9a02011-04-21 15:11:33 +03001311 if (c->ro_mount)
1312 /*
1313 * For some really strange reasons VFS does not filter out
1314 * 'fsync()' for R/O mounted file-systems as per 2.6.39.
1315 */
Artem Bityutskiy78530bf2011-04-13 10:31:52 +03001316 return 0;
1317
Josef Bacik02c24a82011-07-16 20:44:56 -04001318 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
1319 if (err)
1320 return err;
Al Viro59551022016-01-22 15:40:57 -05001321 inode_lock(inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001322
1323 /* Synchronize the inode unless this is a 'datasync()' call. */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001324 if (!datasync || (inode->i_state & I_DIRTY_DATASYNC)) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001325 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001326 if (err)
Josef Bacik02c24a82011-07-16 20:44:56 -04001327 goto out;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001328 }
1329
1330 /*
1331 * Nodes related to this inode may still sit in a write-buffer. Flush
1332 * them.
1333 */
1334 err = ubifs_sync_wbufs_by_inode(c, inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001335out:
Al Viro59551022016-01-22 15:40:57 -05001336 inode_unlock(inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001337 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001338}
1339
1340/**
1341 * mctime_update_needed - check if mtime or ctime update is needed.
1342 * @inode: the inode to do the check for
1343 * @now: current time
1344 *
1345 * This helper function checks if the inode mtime/ctime should be updated or
1346 * not. If current values of the time-stamps are within the UBIFS inode time
1347 * granularity, they are not updated. This is an optimization.
1348 */
1349static inline int mctime_update_needed(const struct inode *inode,
1350 const struct timespec *now)
1351{
1352 if (!timespec_equal(&inode->i_mtime, now) ||
1353 !timespec_equal(&inode->i_ctime, now))
1354 return 1;
1355 return 0;
1356}
1357
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001358#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1359/**
1360 * ubifs_update_time - update time of inode.
1361 * @inode: inode to update
1362 *
1363 * This function updates time of the inode.
1364 */
1365int ubifs_update_time(struct inode *inode, struct timespec *time,
1366 int flags)
1367{
1368 struct ubifs_inode *ui = ubifs_inode(inode);
1369 struct ubifs_info *c = inode->i_sb->s_fs_info;
1370 struct ubifs_budget_req req = { .dirtied_ino = 1,
1371 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
1372 int iflags = I_DIRTY_TIME;
1373 int err, release;
1374
1375 err = ubifs_budget_space(c, &req);
1376 if (err)
1377 return err;
1378
1379 mutex_lock(&ui->ui_mutex);
1380 if (flags & S_ATIME)
1381 inode->i_atime = *time;
1382 if (flags & S_CTIME)
1383 inode->i_ctime = *time;
1384 if (flags & S_MTIME)
1385 inode->i_mtime = *time;
1386
1387 if (!(inode->i_sb->s_flags & MS_LAZYTIME))
1388 iflags |= I_DIRTY_SYNC;
1389
1390 release = ui->dirty;
1391 __mark_inode_dirty(inode, iflags);
1392 mutex_unlock(&ui->ui_mutex);
1393 if (release)
1394 ubifs_release_budget(c, &req);
1395 return 0;
1396}
1397#endif
1398
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001399/**
1400 * update_ctime - update mtime and ctime of an inode.
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001401 * @inode: inode to update
1402 *
1403 * This function updates mtime and ctime of the inode if it is not equivalent to
1404 * current time. Returns zero in case of success and a negative error code in
1405 * case of failure.
1406 */
Al Virof5674c32014-04-03 14:00:23 -04001407static int update_mctime(struct inode *inode)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001408{
1409 struct timespec now = ubifs_current_time(inode);
1410 struct ubifs_inode *ui = ubifs_inode(inode);
Al Virof5674c32014-04-03 14:00:23 -04001411 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001412
1413 if (mctime_update_needed(inode, &now)) {
1414 int err, release;
1415 struct ubifs_budget_req req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001416 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001417
1418 err = ubifs_budget_space(c, &req);
1419 if (err)
1420 return err;
1421
1422 mutex_lock(&ui->ui_mutex);
1423 inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
1424 release = ui->dirty;
1425 mark_inode_dirty_sync(inode);
1426 mutex_unlock(&ui->ui_mutex);
1427 if (release)
1428 ubifs_release_budget(c, &req);
1429 }
1430
1431 return 0;
1432}
1433
Al Virof5674c32014-04-03 14:00:23 -04001434static ssize_t ubifs_write_iter(struct kiocb *iocb, struct iov_iter *from)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001435{
Al Virof5674c32014-04-03 14:00:23 -04001436 int err = update_mctime(file_inode(iocb->ki_filp));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001437 if (err)
1438 return err;
1439
Al Virof5674c32014-04-03 14:00:23 -04001440 return generic_file_write_iter(iocb, from);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001441}
1442
1443static int ubifs_set_page_dirty(struct page *page)
1444{
1445 int ret;
1446
1447 ret = __set_page_dirty_nobuffers(page);
1448 /*
1449 * An attempt to dirty a page without budgeting for it - should not
1450 * happen.
1451 */
1452 ubifs_assert(ret == 0);
1453 return ret;
1454}
1455
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001456#ifdef CONFIG_MIGRATION
1457static int ubifs_migrate_page(struct address_space *mapping,
1458 struct page *newpage, struct page *page, enum migrate_mode mode)
1459{
1460 int rc;
1461
1462 rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0);
1463 if (rc != MIGRATEPAGE_SUCCESS)
1464 return rc;
1465
1466 if (PagePrivate(page)) {
1467 ClearPagePrivate(page);
1468 SetPagePrivate(newpage);
1469 }
1470
1471 migrate_page_copy(newpage, page);
1472 return MIGRATEPAGE_SUCCESS;
1473}
1474#endif
1475
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001476static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags)
1477{
1478 /*
1479 * An attempt to release a dirty page without budgeting for it - should
1480 * not happen.
1481 */
1482 if (PageWriteback(page))
1483 return 0;
1484 ubifs_assert(PagePrivate(page));
1485 ubifs_assert(0);
1486 ClearPagePrivate(page);
1487 ClearPageChecked(page);
1488 return 1;
1489}
1490
1491/*
Artem Bityutskiyc4361572011-03-25 15:27:40 +02001492 * mmap()d file has taken write protection fault and is being made writable.
1493 * UBIFS must ensure page is budgeted for.
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001494 */
Artem Bityutskiyc4361572011-03-25 15:27:40 +02001495static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma,
1496 struct vm_fault *vmf)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001497{
Nick Pigginc2ec1752009-03-31 15:23:21 -07001498 struct page *page = vmf->page;
Al Viro496ad9a2013-01-23 17:07:38 -05001499 struct inode *inode = file_inode(vma->vm_file);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001500 struct ubifs_info *c = inode->i_sb->s_fs_info;
1501 struct timespec now = ubifs_current_time(inode);
1502 struct ubifs_budget_req req = { .new_page = 1 };
1503 int err, update_time;
1504
1505 dbg_gen("ino %lu, pg %lu, i_size %lld", inode->i_ino, page->index,
1506 i_size_read(inode));
Artem Bityutskiy2ef13292010-09-19 18:34:26 +03001507 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001508
Artem Bityutskiy2680d722010-09-17 16:44:28 +03001509 if (unlikely(c->ro_error))
Nick Pigginc2ec1752009-03-31 15:23:21 -07001510 return VM_FAULT_SIGBUS; /* -EROFS */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001511
1512 /*
1513 * We have not locked @page so far so we may budget for changing the
1514 * page. Note, we cannot do this after we locked the page, because
1515 * budgeting may cause write-back which would cause deadlock.
1516 *
1517 * At the moment we do not know whether the page is dirty or not, so we
1518 * assume that it is not and budget for a new page. We could look at
1519 * the @PG_private flag and figure this out, but we may race with write
1520 * back and the page state may change by the time we lock it, so this
1521 * would need additional care. We do not bother with this at the
1522 * moment, although it might be good idea to do. Instead, we allocate
1523 * budget for a new page and amend it later on if the page was in fact
1524 * dirty.
1525 *
1526 * The budgeting-related logic of this function is similar to what we
1527 * do in 'ubifs_write_begin()' and 'ubifs_write_end()'. Glance there
1528 * for more comments.
1529 */
1530 update_time = mctime_update_needed(inode, &now);
1531 if (update_time)
1532 /*
1533 * We have to change inode time stamp which requires extra
1534 * budgeting.
1535 */
1536 req.dirtied_ino = 1;
1537
1538 err = ubifs_budget_space(c, &req);
1539 if (unlikely(err)) {
1540 if (err == -ENOSPC)
Sheng Yong235c3622015-03-20 10:39:42 +00001541 ubifs_warn(c, "out of space for mmapped file (inode number %lu)",
Artem Bityutskiy79fda512012-08-27 13:34:09 +03001542 inode->i_ino);
Nick Pigginc2ec1752009-03-31 15:23:21 -07001543 return VM_FAULT_SIGBUS;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001544 }
1545
1546 lock_page(page);
1547 if (unlikely(page->mapping != inode->i_mapping ||
1548 page_offset(page) > i_size_read(inode))) {
1549 /* Page got truncated out from underneath us */
1550 err = -EINVAL;
1551 goto out_unlock;
1552 }
1553
1554 if (PagePrivate(page))
1555 release_new_page_budget(c);
1556 else {
1557 if (!PageChecked(page))
1558 ubifs_convert_page_budget(c);
1559 SetPagePrivate(page);
1560 atomic_long_inc(&c->dirty_pg_cnt);
1561 __set_page_dirty_nobuffers(page);
1562 }
1563
1564 if (update_time) {
1565 int release;
1566 struct ubifs_inode *ui = ubifs_inode(inode);
1567
1568 mutex_lock(&ui->ui_mutex);
1569 inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
1570 release = ui->dirty;
1571 mark_inode_dirty_sync(inode);
1572 mutex_unlock(&ui->ui_mutex);
1573 if (release)
1574 ubifs_release_dirty_inode_budget(c, ui);
1575 }
1576
Jan Kara182dcfd2013-02-21 16:42:59 -08001577 wait_for_stable_page(page);
hujianyang691a7c62014-04-30 14:06:06 +08001578 return VM_FAULT_LOCKED;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001579
1580out_unlock:
1581 unlock_page(page);
1582 ubifs_release_budget(c, &req);
Nick Pigginc2ec1752009-03-31 15:23:21 -07001583 if (err)
1584 err = VM_FAULT_SIGBUS;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001585 return err;
1586}
1587
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +04001588static const struct vm_operations_struct ubifs_file_vm_ops = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001589 .fault = filemap_fault,
Kirill A. Shutemovf1820362014-04-07 15:37:19 -07001590 .map_pages = filemap_map_pages,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001591 .page_mkwrite = ubifs_vm_page_mkwrite,
1592};
1593
1594static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1595{
1596 int err;
1597
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001598 err = generic_file_mmap(file, vma);
1599 if (err)
1600 return err;
1601 vma->vm_ops = &ubifs_file_vm_ops;
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001602#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1603 file_accessed(file);
1604#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001605 return 0;
1606}
1607
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001608const struct address_space_operations ubifs_file_address_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001609 .readpage = ubifs_readpage,
1610 .writepage = ubifs_writepage,
1611 .write_begin = ubifs_write_begin,
1612 .write_end = ubifs_write_end,
1613 .invalidatepage = ubifs_invalidatepage,
1614 .set_page_dirty = ubifs_set_page_dirty,
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001615#ifdef CONFIG_MIGRATION
1616 .migratepage = ubifs_migrate_page,
1617#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001618 .releasepage = ubifs_releasepage,
1619};
1620
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001621const struct inode_operations ubifs_file_inode_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001622 .setattr = ubifs_setattr,
1623 .getattr = ubifs_getattr,
Andreas Gruenbacher2b88fc22016-04-22 19:14:00 +02001624 .setxattr = generic_setxattr,
1625 .getxattr = generic_getxattr,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001626 .listxattr = ubifs_listxattr,
Andreas Gruenbacher2b88fc22016-04-22 19:14:00 +02001627 .removexattr = generic_removexattr,
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001628#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1629 .update_time = ubifs_update_time,
1630#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001631};
1632
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001633const struct inode_operations ubifs_symlink_inode_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001634 .readlink = generic_readlink,
Al Viro6b255392015-11-17 10:20:54 -05001635 .get_link = simple_get_link,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001636 .setattr = ubifs_setattr,
1637 .getattr = ubifs_getattr,
Andreas Gruenbacher2b88fc22016-04-22 19:14:00 +02001638 .setxattr = generic_setxattr,
1639 .getxattr = generic_getxattr,
Subodh Nijsure895d9db22014-10-31 13:50:29 -05001640 .listxattr = ubifs_listxattr,
Andreas Gruenbacher2b88fc22016-04-22 19:14:00 +02001641 .removexattr = generic_removexattr,
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001642#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1643 .update_time = ubifs_update_time,
1644#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001645};
1646
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001647const struct file_operations ubifs_file_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001648 .llseek = generic_file_llseek,
Al Viroaad4f8b2014-04-02 14:33:16 -04001649 .read_iter = generic_file_read_iter,
Al Virof5674c32014-04-03 14:00:23 -04001650 .write_iter = ubifs_write_iter,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001651 .mmap = ubifs_file_mmap,
1652 .fsync = ubifs_fsync,
1653 .unlocked_ioctl = ubifs_ioctl,
1654 .splice_read = generic_file_splice_read,
Al Viro8d020762014-04-05 04:27:08 -04001655 .splice_write = iter_file_splice_write,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001656#ifdef CONFIG_COMPAT
1657 .compat_ioctl = ubifs_compat_ioctl,
1658#endif
1659};