blob: 8cad0b19b404cc20be28835a6c99919fa2ef9aae [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;
Richard Weinberger77999532016-09-29 22:20:19 +020081
82 if (ubifs_crypt_is_encrypted(inode)) {
83 err = ubifs_decrypt(inode, dn, &dlen, block);
84 if (err)
85 goto dump;
86 }
87
Artem Bityutskiy1e517642008-07-14 19:08:37 +030088 out_len = UBIFS_BLOCK_SIZE;
Sheng Yong235c3622015-03-20 10:39:42 +000089 err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
Artem Bityutskiy1e517642008-07-14 19:08:37 +030090 le16_to_cpu(dn->compr_type));
91 if (err || len != out_len)
92 goto dump;
93
94 /*
95 * Data length can be less than a full block, even for blocks that are
96 * not the last in the file (e.g., as a result of making a hole and
97 * appending data). Ensure that the remainder is zeroed out.
98 */
99 if (len < UBIFS_BLOCK_SIZE)
100 memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
101
102 return 0;
103
104dump:
Sheng Yong235c3622015-03-20 10:39:42 +0000105 ubifs_err(c, "bad data node (block %u, inode %lu)",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300106 block, inode->i_ino);
Artem Bityutskiyedf6be22012-05-16 19:15:56 +0300107 ubifs_dump_node(c, dn);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300108 return -EINVAL;
109}
110
111static int do_readpage(struct page *page)
112{
113 void *addr;
114 int err = 0, i;
115 unsigned int block, beyond;
116 struct ubifs_data_node *dn;
117 struct inode *inode = page->mapping->host;
118 loff_t i_size = i_size_read(inode);
119
120 dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
121 inode->i_ino, page->index, i_size, page->flags);
122 ubifs_assert(!PageChecked(page));
123 ubifs_assert(!PagePrivate(page));
124
125 addr = kmap(page);
126
127 block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
128 beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
129 if (block >= beyond) {
130 /* Reading beyond inode */
131 SetPageChecked(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300132 memset(addr, 0, PAGE_SIZE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300133 goto out;
134 }
135
136 dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
137 if (!dn) {
138 err = -ENOMEM;
139 goto error;
140 }
141
142 i = 0;
143 while (1) {
144 int ret;
145
146 if (block >= beyond) {
147 /* Reading beyond inode */
148 err = -ENOENT;
149 memset(addr, 0, UBIFS_BLOCK_SIZE);
150 } else {
151 ret = read_block(inode, addr, block, dn);
152 if (ret) {
153 err = ret;
154 if (err != -ENOENT)
155 break;
Adrian Huntered382d52008-09-05 16:17:42 +0300156 } else if (block + 1 == beyond) {
157 int dlen = le32_to_cpu(dn->size);
158 int ilen = i_size & (UBIFS_BLOCK_SIZE - 1);
159
160 if (ilen && ilen < dlen)
161 memset(addr + ilen, 0, dlen - ilen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300162 }
163 }
164 if (++i >= UBIFS_BLOCKS_PER_PAGE)
165 break;
166 block += 1;
167 addr += UBIFS_BLOCK_SIZE;
168 }
169 if (err) {
Sheng Yong235c3622015-03-20 10:39:42 +0000170 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300171 if (err == -ENOENT) {
172 /* Not found, so it must be a hole */
173 SetPageChecked(page);
174 dbg_gen("hole");
175 goto out_free;
176 }
Sheng Yong235c3622015-03-20 10:39:42 +0000177 ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300178 page->index, inode->i_ino, err);
179 goto error;
180 }
181
182out_free:
183 kfree(dn);
184out:
185 SetPageUptodate(page);
186 ClearPageError(page);
187 flush_dcache_page(page);
188 kunmap(page);
189 return 0;
190
191error:
192 kfree(dn);
193 ClearPageUptodate(page);
194 SetPageError(page);
195 flush_dcache_page(page);
196 kunmap(page);
197 return err;
198}
199
200/**
201 * release_new_page_budget - release budget of a new page.
202 * @c: UBIFS file-system description object
203 *
204 * This is a helper function which releases budget corresponding to the budget
205 * of one new page of data.
206 */
207static void release_new_page_budget(struct ubifs_info *c)
208{
209 struct ubifs_budget_req req = { .recalculate = 1, .new_page = 1 };
210
211 ubifs_release_budget(c, &req);
212}
213
214/**
215 * release_existing_page_budget - release budget of an existing page.
216 * @c: UBIFS file-system description object
217 *
218 * This is a helper function which releases budget corresponding to the budget
219 * of changing one one page of data which already exists on the flash media.
220 */
221static void release_existing_page_budget(struct ubifs_info *c)
222{
Artem Bityutskiyb1375452011-03-29 18:04:05 +0300223 struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget};
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300224
225 ubifs_release_budget(c, &req);
226}
227
228static int write_begin_slow(struct address_space *mapping,
Nick Piggin54566b22009-01-04 12:00:53 -0800229 loff_t pos, unsigned len, struct page **pagep,
230 unsigned flags)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300231{
232 struct inode *inode = mapping->host;
233 struct ubifs_info *c = inode->i_sb->s_fs_info;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300234 pgoff_t index = pos >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300235 struct ubifs_budget_req req = { .new_page = 1 };
236 int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
237 struct page *page;
238
239 dbg_gen("ino %lu, pos %llu, len %u, i_size %lld",
240 inode->i_ino, pos, len, inode->i_size);
241
242 /*
243 * At the slow path we have to budget before locking the page, because
244 * budgeting may force write-back, which would wait on locked pages and
245 * deadlock if we had the page locked. At this point we do not know
246 * anything about the page, so assume that this is a new page which is
247 * written to a hole. This corresponds to largest budget. Later the
248 * budget will be amended if this is not true.
249 */
250 if (appending)
251 /* We are appending data, budget for inode change */
252 req.dirtied_ino = 1;
253
254 err = ubifs_budget_space(c, &req);
255 if (unlikely(err))
256 return err;
257
Nick Piggin54566b22009-01-04 12:00:53 -0800258 page = grab_cache_page_write_begin(mapping, index, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300259 if (unlikely(!page)) {
260 ubifs_release_budget(c, &req);
261 return -ENOMEM;
262 }
263
264 if (!PageUptodate(page)) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300265 if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300266 SetPageChecked(page);
267 else {
268 err = do_readpage(page);
269 if (err) {
270 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300271 put_page(page);
Artem Bityutskiy789c8992014-10-20 17:52:31 +0300272 ubifs_release_budget(c, &req);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300273 return err;
274 }
275 }
276
277 SetPageUptodate(page);
278 ClearPageError(page);
279 }
280
281 if (PagePrivate(page))
282 /*
283 * The page is dirty, which means it was budgeted twice:
284 * o first time the budget was allocated by the task which
285 * made the page dirty and set the PG_private flag;
286 * o and then we budgeted for it for the second time at the
287 * very beginning of this function.
288 *
289 * So what we have to do is to release the page budget we
290 * allocated.
291 */
292 release_new_page_budget(c);
293 else if (!PageChecked(page))
294 /*
295 * We are changing a page which already exists on the media.
296 * This means that changing the page does not make the amount
297 * of indexing information larger, and this part of the budget
298 * which we have already acquired may be released.
299 */
300 ubifs_convert_page_budget(c);
301
302 if (appending) {
303 struct ubifs_inode *ui = ubifs_inode(inode);
304
305 /*
306 * 'ubifs_write_end()' is optimized from the fast-path part of
307 * 'ubifs_write_begin()' and expects the @ui_mutex to be locked
308 * if data is appended.
309 */
310 mutex_lock(&ui->ui_mutex);
311 if (ui->dirty)
312 /*
313 * The inode is dirty already, so we may free the
314 * budget we allocated.
315 */
316 ubifs_release_dirty_inode_budget(c, ui);
317 }
318
319 *pagep = page;
320 return 0;
321}
322
323/**
324 * allocate_budget - allocate budget for 'ubifs_write_begin()'.
325 * @c: UBIFS file-system description object
326 * @page: page to allocate budget for
327 * @ui: UBIFS inode object the page belongs to
328 * @appending: non-zero if the page is appended
329 *
330 * This is a helper function for 'ubifs_write_begin()' which allocates budget
331 * for the operation. The budget is allocated differently depending on whether
332 * this is appending, whether the page is dirty or not, and so on. This
333 * function leaves the @ui->ui_mutex locked in case of appending. Returns zero
334 * in case of success and %-ENOSPC in case of failure.
335 */
336static int allocate_budget(struct ubifs_info *c, struct page *page,
337 struct ubifs_inode *ui, int appending)
338{
339 struct ubifs_budget_req req = { .fast = 1 };
340
341 if (PagePrivate(page)) {
342 if (!appending)
343 /*
344 * The page is dirty and we are not appending, which
345 * means no budget is needed at all.
346 */
347 return 0;
348
349 mutex_lock(&ui->ui_mutex);
350 if (ui->dirty)
351 /*
352 * The page is dirty and we are appending, so the inode
353 * has to be marked as dirty. However, it is already
354 * dirty, so we do not need any budget. We may return,
355 * but @ui->ui_mutex hast to be left locked because we
356 * should prevent write-back from flushing the inode
357 * and freeing the budget. The lock will be released in
358 * 'ubifs_write_end()'.
359 */
360 return 0;
361
362 /*
363 * The page is dirty, we are appending, the inode is clean, so
364 * we need to budget the inode change.
365 */
366 req.dirtied_ino = 1;
367 } else {
368 if (PageChecked(page))
369 /*
370 * The page corresponds to a hole and does not
371 * exist on the media. So changing it makes
372 * make the amount of indexing information
373 * larger, and we have to budget for a new
374 * page.
375 */
376 req.new_page = 1;
377 else
378 /*
379 * Not a hole, the change will not add any new
380 * indexing information, budget for page
381 * change.
382 */
383 req.dirtied_page = 1;
384
385 if (appending) {
386 mutex_lock(&ui->ui_mutex);
387 if (!ui->dirty)
388 /*
389 * The inode is clean but we will have to mark
390 * it as dirty because we are appending. This
391 * needs a budget.
392 */
393 req.dirtied_ino = 1;
394 }
395 }
396
397 return ubifs_budget_space(c, &req);
398}
399
400/*
401 * This function is called when a page of data is going to be written. Since
402 * the page of data will not necessarily go to the flash straight away, UBIFS
403 * has to reserve space on the media for it, which is done by means of
404 * budgeting.
405 *
406 * This is the hot-path of the file-system and we are trying to optimize it as
407 * much as possible. For this reasons it is split on 2 parts - slow and fast.
408 *
409 * There many budgeting cases:
410 * o a new page is appended - we have to budget for a new page and for
411 * changing the inode; however, if the inode is already dirty, there is
412 * no need to budget for it;
413 * o an existing clean page is changed - we have budget for it; if the page
414 * does not exist on the media (a hole), we have to budget for a new
415 * page; otherwise, we may budget for changing an existing page; the
416 * difference between these cases is that changing an existing page does
417 * not introduce anything new to the FS indexing information, so it does
418 * not grow, and smaller budget is acquired in this case;
419 * o an existing dirty page is changed - no need to budget at all, because
420 * the page budget has been acquired by earlier, when the page has been
421 * marked dirty.
422 *
423 * UBIFS budgeting sub-system may force write-back if it thinks there is no
424 * space to reserve. This imposes some locking restrictions and makes it
425 * impossible to take into account the above cases, and makes it impossible to
426 * optimize budgeting.
427 *
428 * The solution for this is that the fast path of 'ubifs_write_begin()' assumes
429 * there is a plenty of flash space and the budget will be acquired quickly,
430 * without forcing write-back. The slow path does not make this assumption.
431 */
432static int ubifs_write_begin(struct file *file, struct address_space *mapping,
433 loff_t pos, unsigned len, unsigned flags,
434 struct page **pagep, void **fsdata)
435{
436 struct inode *inode = mapping->host;
437 struct ubifs_info *c = inode->i_sb->s_fs_info;
438 struct ubifs_inode *ui = ubifs_inode(inode);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300439 pgoff_t index = pos >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300440 int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
Adrian Hunterf55aa592009-02-23 12:47:25 +0200441 int skipped_read = 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300442 struct page *page;
443
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300444 ubifs_assert(ubifs_inode(inode)->ui_size == inode->i_size);
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300445 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300446
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300447 if (unlikely(c->ro_error))
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300448 return -EROFS;
449
450 /* Try out the fast-path part first */
Nick Piggin54566b22009-01-04 12:00:53 -0800451 page = grab_cache_page_write_begin(mapping, index, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300452 if (unlikely(!page))
453 return -ENOMEM;
454
455 if (!PageUptodate(page)) {
456 /* The page is not loaded from the flash */
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300457 if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300458 /*
459 * We change whole page so no need to load it. But we
Artem Bityutskiy6ed09c32011-03-23 10:32:58 +0200460 * do not know whether this page exists on the media or
461 * not, so we assume the latter because it requires
462 * larger budget. The assumption is that it is better
463 * to budget a bit more than to read the page from the
464 * media. Thus, we are setting the @PG_checked flag
465 * here.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300466 */
467 SetPageChecked(page);
Adrian Hunterf55aa592009-02-23 12:47:25 +0200468 skipped_read = 1;
469 } else {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300470 err = do_readpage(page);
471 if (err) {
472 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300473 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300474 return err;
475 }
476 }
477
478 SetPageUptodate(page);
479 ClearPageError(page);
480 }
481
482 err = allocate_budget(c, page, ui, appending);
483 if (unlikely(err)) {
484 ubifs_assert(err == -ENOSPC);
485 /*
Adrian Hunterf55aa592009-02-23 12:47:25 +0200486 * If we skipped reading the page because we were going to
487 * write all of it, then it is not up to date.
488 */
489 if (skipped_read) {
490 ClearPageChecked(page);
491 ClearPageUptodate(page);
492 }
493 /*
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300494 * Budgeting failed which means it would have to force
495 * write-back but didn't, because we set the @fast flag in the
496 * request. Write-back cannot be done now, while we have the
497 * page locked, because it would deadlock. Unlock and free
498 * everything and fall-back to slow-path.
499 */
500 if (appending) {
501 ubifs_assert(mutex_is_locked(&ui->ui_mutex));
502 mutex_unlock(&ui->ui_mutex);
503 }
504 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300505 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300506
Nick Piggin54566b22009-01-04 12:00:53 -0800507 return write_begin_slow(mapping, pos, len, pagep, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300508 }
509
510 /*
Artem Bityutskiy873a64c2009-09-01 17:06:43 +0300511 * Whee, we acquired budgeting quickly - without involving
512 * garbage-collection, committing or forcing write-back. We return
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300513 * with @ui->ui_mutex locked if we are appending pages, and unlocked
514 * otherwise. This is an optimization (slightly hacky though).
515 */
516 *pagep = page;
517 return 0;
518
519}
520
521/**
522 * cancel_budget - cancel budget.
523 * @c: UBIFS file-system description object
524 * @page: page to cancel budget for
525 * @ui: UBIFS inode object the page belongs to
526 * @appending: non-zero if the page is appended
527 *
528 * This is a helper function for a page write operation. It unlocks the
529 * @ui->ui_mutex in case of appending.
530 */
531static void cancel_budget(struct ubifs_info *c, struct page *page,
532 struct ubifs_inode *ui, int appending)
533{
534 if (appending) {
535 if (!ui->dirty)
536 ubifs_release_dirty_inode_budget(c, ui);
537 mutex_unlock(&ui->ui_mutex);
538 }
539 if (!PagePrivate(page)) {
540 if (PageChecked(page))
541 release_new_page_budget(c);
542 else
543 release_existing_page_budget(c);
544 }
545}
546
547static int ubifs_write_end(struct file *file, struct address_space *mapping,
548 loff_t pos, unsigned len, unsigned copied,
549 struct page *page, void *fsdata)
550{
551 struct inode *inode = mapping->host;
552 struct ubifs_inode *ui = ubifs_inode(inode);
553 struct ubifs_info *c = inode->i_sb->s_fs_info;
554 loff_t end_pos = pos + len;
555 int appending = !!(end_pos > inode->i_size);
556
557 dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld",
558 inode->i_ino, pos, page->index, len, copied, inode->i_size);
559
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300560 if (unlikely(copied < len && len == PAGE_SIZE)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300561 /*
562 * VFS copied less data to the page that it intended and
563 * declared in its '->write_begin()' call via the @len
564 * argument. If the page was not up-to-date, and @len was
Kirill A. Shutemovea1754a2016-04-01 15:29:48 +0300565 * @PAGE_SIZE, the 'ubifs_write_begin()' function did
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300566 * not load it from the media (for optimization reasons). This
567 * means that part of the page contains garbage. So read the
568 * page now.
569 */
570 dbg_gen("copied %d instead of %d, read page and repeat",
571 copied, len);
572 cancel_budget(c, page, ui, appending);
Artem Bityutskiy6ed09c32011-03-23 10:32:58 +0200573 ClearPageChecked(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300574
575 /*
576 * Return 0 to force VFS to repeat the whole operation, or the
Artem Bityutskiy873a64c2009-09-01 17:06:43 +0300577 * error code if 'do_readpage()' fails.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300578 */
579 copied = do_readpage(page);
580 goto out;
581 }
582
583 if (!PagePrivate(page)) {
584 SetPagePrivate(page);
585 atomic_long_inc(&c->dirty_pg_cnt);
586 __set_page_dirty_nobuffers(page);
587 }
588
589 if (appending) {
590 i_size_write(inode, end_pos);
591 ui->ui_size = end_pos;
592 /*
593 * Note, we do not set @I_DIRTY_PAGES (which means that the
594 * inode has dirty pages), this has been done in
595 * '__set_page_dirty_nobuffers()'.
596 */
597 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
598 ubifs_assert(mutex_is_locked(&ui->ui_mutex));
599 mutex_unlock(&ui->ui_mutex);
600 }
601
602out:
603 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300604 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300605 return copied;
606}
607
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300608/**
609 * populate_page - copy data nodes into a page for bulk-read.
610 * @c: UBIFS file-system description object
611 * @page: page
612 * @bu: bulk-read information
613 * @n: next zbranch slot
614 *
615 * This function returns %0 on success and a negative error code on failure.
616 */
617static int populate_page(struct ubifs_info *c, struct page *page,
618 struct bu_info *bu, int *n)
619{
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300620 int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300621 struct inode *inode = page->mapping->host;
622 loff_t i_size = i_size_read(inode);
623 unsigned int page_block;
624 void *addr, *zaddr;
625 pgoff_t end_index;
626
627 dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
628 inode->i_ino, page->index, i_size, page->flags);
629
630 addr = zaddr = kmap(page);
631
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300632 end_index = (i_size - 1) >> PAGE_SHIFT;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300633 if (!i_size || page->index > end_index) {
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300634 hole = 1;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300635 memset(addr, 0, PAGE_SIZE);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300636 goto out_hole;
637 }
638
639 page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
640 while (1) {
641 int err, len, out_len, dlen;
642
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300643 if (nn >= bu->cnt) {
644 hole = 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300645 memset(addr, 0, UBIFS_BLOCK_SIZE);
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300646 } else if (key_block(c, &bu->zbranch[nn].key) == page_block) {
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300647 struct ubifs_data_node *dn;
648
649 dn = bu->buf + (bu->zbranch[nn].offs - offs);
650
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700651 ubifs_assert(le64_to_cpu(dn->ch.sqnum) >
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300652 ubifs_inode(inode)->creat_sqnum);
653
654 len = le32_to_cpu(dn->size);
655 if (len <= 0 || len > UBIFS_BLOCK_SIZE)
656 goto out_err;
657
658 dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
659 out_len = UBIFS_BLOCK_SIZE;
Richard Weinberger77999532016-09-29 22:20:19 +0200660
661 if (ubifs_crypt_is_encrypted(inode)) {
662 err = ubifs_decrypt(inode, dn, &dlen, page_block);
663 if (err)
664 goto out_err;
665 }
666
Sheng Yong235c3622015-03-20 10:39:42 +0000667 err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300668 le16_to_cpu(dn->compr_type));
669 if (err || len != out_len)
670 goto out_err;
671
672 if (len < UBIFS_BLOCK_SIZE)
673 memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
674
675 nn += 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300676 read = (i << UBIFS_BLOCK_SHIFT) + len;
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300677 } else if (key_block(c, &bu->zbranch[nn].key) < page_block) {
678 nn += 1;
679 continue;
680 } else {
681 hole = 1;
682 memset(addr, 0, UBIFS_BLOCK_SIZE);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300683 }
684 if (++i >= UBIFS_BLOCKS_PER_PAGE)
685 break;
686 addr += UBIFS_BLOCK_SIZE;
687 page_block += 1;
688 }
689
690 if (end_index == page->index) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300691 int len = i_size & (PAGE_SIZE - 1);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300692
Adrian Huntered382d52008-09-05 16:17:42 +0300693 if (len && len < read)
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300694 memset(zaddr + len, 0, read - len);
695 }
696
697out_hole:
698 if (hole) {
699 SetPageChecked(page);
700 dbg_gen("hole");
701 }
702
703 SetPageUptodate(page);
704 ClearPageError(page);
705 flush_dcache_page(page);
706 kunmap(page);
707 *n = nn;
708 return 0;
709
710out_err:
711 ClearPageUptodate(page);
712 SetPageError(page);
713 flush_dcache_page(page);
714 kunmap(page);
Sheng Yong235c3622015-03-20 10:39:42 +0000715 ubifs_err(c, "bad data node (block %u, inode %lu)",
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300716 page_block, inode->i_ino);
717 return -EINVAL;
718}
719
720/**
721 * ubifs_do_bulk_read - do bulk-read.
722 * @c: UBIFS file-system description object
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200723 * @bu: bulk-read information
724 * @page1: first page to read
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300725 *
726 * This function returns %1 if the bulk-read is done, otherwise %0 is returned.
727 */
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200728static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu,
729 struct page *page1)
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300730{
731 pgoff_t offset = page1->index, end_index;
732 struct address_space *mapping = page1->mapping;
733 struct inode *inode = mapping->host;
734 struct ubifs_inode *ui = ubifs_inode(inode);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300735 int err, page_idx, page_cnt, ret = 0, n = 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200736 int allocate = bu->buf ? 0 : 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300737 loff_t isize;
Hyunchul Lee480a1a62017-06-14 09:31:49 +0900738 gfp_t ra_gfp_mask = readahead_gfp_mask(mapping) & ~__GFP_FS;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300739
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300740 err = ubifs_tnc_get_bu_keys(c, bu);
741 if (err)
742 goto out_warn;
743
744 if (bu->eof) {
745 /* Turn off bulk-read at the end of the file */
746 ui->read_in_a_row = 1;
747 ui->bulk_read = 0;
748 }
749
750 page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT;
751 if (!page_cnt) {
752 /*
753 * This happens when there are multiple blocks per page and the
754 * blocks for the first page we are looking for, are not
755 * together. If all the pages were like this, bulk-read would
756 * reduce performance, so we turn it off for a while.
757 */
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200758 goto out_bu_off;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300759 }
760
761 if (bu->cnt) {
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200762 if (allocate) {
763 /*
764 * Allocate bulk-read buffer depending on how many data
765 * nodes we are going to read.
766 */
767 bu->buf_len = bu->zbranch[bu->cnt - 1].offs +
768 bu->zbranch[bu->cnt - 1].len -
769 bu->zbranch[0].offs;
770 ubifs_assert(bu->buf_len > 0);
771 ubifs_assert(bu->buf_len <= c->leb_size);
772 bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN);
773 if (!bu->buf)
774 goto out_bu_off;
775 }
776
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300777 err = ubifs_tnc_bulk_read(c, bu);
778 if (err)
779 goto out_warn;
780 }
781
782 err = populate_page(c, page1, bu, &n);
783 if (err)
784 goto out_warn;
785
786 unlock_page(page1);
787 ret = 1;
788
789 isize = i_size_read(inode);
790 if (isize == 0)
791 goto out_free;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300792 end_index = ((isize - 1) >> PAGE_SHIFT);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300793
794 for (page_idx = 1; page_idx < page_cnt; page_idx++) {
795 pgoff_t page_offset = offset + page_idx;
796 struct page *page;
797
798 if (page_offset > end_index)
799 break;
Hyunchul Lee480a1a62017-06-14 09:31:49 +0900800 page = find_or_create_page(mapping, page_offset, ra_gfp_mask);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300801 if (!page)
802 break;
803 if (!PageUptodate(page))
804 err = populate_page(c, page, bu, &n);
805 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300806 put_page(page);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300807 if (err)
808 break;
809 }
810
811 ui->last_page_read = offset + page_idx - 1;
812
813out_free:
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200814 if (allocate)
815 kfree(bu->buf);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300816 return ret;
817
818out_warn:
Sheng Yong235c3622015-03-20 10:39:42 +0000819 ubifs_warn(c, "ignoring error %d and skipping bulk-read", err);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300820 goto out_free;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200821
822out_bu_off:
823 ui->read_in_a_row = ui->bulk_read = 0;
824 goto out_free;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300825}
826
827/**
828 * ubifs_bulk_read - determine whether to bulk-read and, if so, do it.
829 * @page: page from which to start bulk-read.
830 *
831 * Some flash media are capable of reading sequentially at faster rates. UBIFS
832 * bulk-read facility is designed to take advantage of that, by reading in one
833 * go consecutive data nodes that are also located consecutively in the same
834 * LEB. This function returns %1 if a bulk-read is done and %0 otherwise.
835 */
836static int ubifs_bulk_read(struct page *page)
837{
838 struct inode *inode = page->mapping->host;
839 struct ubifs_info *c = inode->i_sb->s_fs_info;
840 struct ubifs_inode *ui = ubifs_inode(inode);
841 pgoff_t index = page->index, last_page_read = ui->last_page_read;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200842 struct bu_info *bu;
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200843 int err = 0, allocated = 0;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300844
845 ui->last_page_read = index;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300846 if (!c->bulk_read)
847 return 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200848
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300849 /*
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200850 * Bulk-read is protected by @ui->ui_mutex, but it is an optimization,
851 * so don't bother if we cannot lock the mutex.
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300852 */
853 if (!mutex_trylock(&ui->ui_mutex))
854 return 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200855
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300856 if (index != last_page_read + 1) {
857 /* Turn off bulk-read if we stop reading sequentially */
858 ui->read_in_a_row = 1;
859 if (ui->bulk_read)
860 ui->bulk_read = 0;
861 goto out_unlock;
862 }
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200863
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300864 if (!ui->bulk_read) {
865 ui->read_in_a_row += 1;
866 if (ui->read_in_a_row < 3)
867 goto out_unlock;
868 /* Three reads in a row, so switch on bulk-read */
869 ui->bulk_read = 1;
870 }
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200871
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200872 /*
873 * If possible, try to use pre-allocated bulk-read information, which
874 * is protected by @c->bu_mutex.
875 */
876 if (mutex_trylock(&c->bu_mutex))
877 bu = &c->bu;
878 else {
879 bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN);
880 if (!bu)
881 goto out_unlock;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200882
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200883 bu->buf = NULL;
884 allocated = 1;
885 }
886
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200887 bu->buf_len = c->max_bu_buf_len;
888 data_key_init(c, &bu->key, inode->i_ino,
889 page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200890 err = ubifs_do_bulk_read(c, bu, page);
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200891
892 if (!allocated)
893 mutex_unlock(&c->bu_mutex);
894 else
895 kfree(bu);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200896
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300897out_unlock:
898 mutex_unlock(&ui->ui_mutex);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200899 return err;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300900}
901
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300902static int ubifs_readpage(struct file *file, struct page *page)
903{
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300904 if (ubifs_bulk_read(page))
905 return 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300906 do_readpage(page);
907 unlock_page(page);
908 return 0;
909}
910
911static int do_writepage(struct page *page, int len)
912{
913 int err = 0, i, blen;
914 unsigned int block;
915 void *addr;
916 union ubifs_key key;
917 struct inode *inode = page->mapping->host;
918 struct ubifs_info *c = inode->i_sb->s_fs_info;
919
920#ifdef UBIFS_DEBUG
Daniel Gollea0fd5952014-05-13 22:27:58 +0200921 struct ubifs_inode *ui = ubifs_inode(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300922 spin_lock(&ui->ui_lock);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300923 ubifs_assert(page->index <= ui->synced_i_size >> PAGE_SHIFT);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300924 spin_unlock(&ui->ui_lock);
925#endif
926
927 /* Update radix tree tags */
928 set_page_writeback(page);
929
930 addr = kmap(page);
931 block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
932 i = 0;
933 while (len) {
934 blen = min_t(int, len, UBIFS_BLOCK_SIZE);
935 data_key_init(c, &key, inode->i_ino, block);
936 err = ubifs_jnl_write_data(c, inode, &key, addr, blen);
937 if (err)
938 break;
939 if (++i >= UBIFS_BLOCKS_PER_PAGE)
940 break;
941 block += 1;
942 addr += blen;
943 len -= blen;
944 }
945 if (err) {
946 SetPageError(page);
Sheng Yong235c3622015-03-20 10:39:42 +0000947 ubifs_err(c, "cannot write page %lu of inode %lu, error %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300948 page->index, inode->i_ino, err);
949 ubifs_ro_mode(c, err);
950 }
951
952 ubifs_assert(PagePrivate(page));
953 if (PageChecked(page))
954 release_new_page_budget(c);
955 else
956 release_existing_page_budget(c);
957
958 atomic_long_dec(&c->dirty_pg_cnt);
959 ClearPagePrivate(page);
960 ClearPageChecked(page);
961
962 kunmap(page);
963 unlock_page(page);
964 end_page_writeback(page);
965 return err;
966}
967
968/*
969 * When writing-back dirty inodes, VFS first writes-back pages belonging to the
970 * inode, then the inode itself. For UBIFS this may cause a problem. Consider a
971 * situation when a we have an inode with size 0, then a megabyte of data is
972 * appended to the inode, then write-back starts and flushes some amount of the
973 * dirty pages, the journal becomes full, commit happens and finishes, and then
974 * an unclean reboot happens. When the file system is mounted next time, the
975 * inode size would still be 0, but there would be many pages which are beyond
976 * the inode size, they would be indexed and consume flash space. Because the
977 * journal has been committed, the replay would not be able to detect this
978 * situation and correct the inode size. This means UBIFS would have to scan
979 * whole index and correct all inode sizes, which is long an unacceptable.
980 *
981 * To prevent situations like this, UBIFS writes pages back only if they are
Artem Bityutskiy7d4e9cc2009-03-20 19:11:12 +0200982 * within the last synchronized inode size, i.e. the size which has been
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300983 * written to the flash media last time. Otherwise, UBIFS forces inode
984 * write-back, thus making sure the on-flash inode contains current inode size,
985 * and then keeps writing pages back.
986 *
987 * Some locking issues explanation. 'ubifs_writepage()' first is called with
988 * the page locked, and it locks @ui_mutex. However, write-back does take inode
989 * @i_mutex, which means other VFS operations may be run on this inode at the
990 * same time. And the problematic one is truncation to smaller size, from where
Artem Bityutskiyc4361572011-03-25 15:27:40 +0200991 * we have to call 'truncate_setsize()', which first changes @inode->i_size,
992 * then drops the truncated pages. And while dropping the pages, it takes the
993 * page lock. This means that 'do_truncation()' cannot call 'truncate_setsize()'
994 * with @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'.
995 * This means that @inode->i_size is changed while @ui_mutex is unlocked.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300996 *
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200997 * XXX(truncate): with the new truncate sequence this is not true anymore,
998 * and the calls to truncate_setsize can be move around freely. They should
999 * be moved to the very end of the truncate sequence.
npiggin@suse.de15c6fd92010-05-27 01:05:34 +10001000 *
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001001 * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond
1002 * inode size. How do we do this if @inode->i_size may became smaller while we
1003 * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the
1004 * @ui->ui_isize "shadow" field which UBIFS uses instead of @inode->i_size
1005 * internally and updates it under @ui_mutex.
1006 *
1007 * Q: why we do not worry that if we race with truncation, we may end up with a
1008 * situation when the inode is truncated while we are in the middle of
1009 * 'do_writepage()', so we do write beyond inode size?
1010 * A: If we are in the middle of 'do_writepage()', truncation would be locked
1011 * on the page lock and it would not write the truncated inode node to the
1012 * journal before we have finished.
1013 */
1014static int ubifs_writepage(struct page *page, struct writeback_control *wbc)
1015{
1016 struct inode *inode = page->mapping->host;
1017 struct ubifs_inode *ui = ubifs_inode(inode);
1018 loff_t i_size = i_size_read(inode), synced_i_size;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001019 pgoff_t end_index = i_size >> PAGE_SHIFT;
1020 int err, len = i_size & (PAGE_SIZE - 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001021 void *kaddr;
1022
1023 dbg_gen("ino %lu, pg %lu, pg flags %#lx",
1024 inode->i_ino, page->index, page->flags);
1025 ubifs_assert(PagePrivate(page));
1026
1027 /* Is the page fully outside @i_size? (truncate in progress) */
1028 if (page->index > end_index || (page->index == end_index && !len)) {
1029 err = 0;
1030 goto out_unlock;
1031 }
1032
1033 spin_lock(&ui->ui_lock);
1034 synced_i_size = ui->synced_i_size;
1035 spin_unlock(&ui->ui_lock);
1036
1037 /* Is the page fully inside @i_size? */
1038 if (page->index < end_index) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001039 if (page->index >= synced_i_size >> PAGE_SHIFT) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001040 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001041 if (err)
1042 goto out_unlock;
1043 /*
1044 * The inode has been written, but the write-buffer has
1045 * not been synchronized, so in case of an unclean
1046 * reboot we may end up with some pages beyond inode
1047 * size, but they would be in the journal (because
1048 * commit flushes write buffers) and recovery would deal
1049 * with this.
1050 */
1051 }
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001052 return do_writepage(page, PAGE_SIZE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001053 }
1054
1055 /*
1056 * The page straddles @i_size. It must be zeroed out on each and every
1057 * writepage invocation because it may be mmapped. "A file is mapped
1058 * in multiples of the page size. For a file that is not a multiple of
1059 * the page size, the remaining memory is zeroed when mapped, and
1060 * writes to that region are not written out to the file."
1061 */
Cong Wanga1c7c132011-11-25 23:14:36 +08001062 kaddr = kmap_atomic(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001063 memset(kaddr + len, 0, PAGE_SIZE - len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001064 flush_dcache_page(page);
Cong Wanga1c7c132011-11-25 23:14:36 +08001065 kunmap_atomic(kaddr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001066
1067 if (i_size > synced_i_size) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001068 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001069 if (err)
1070 goto out_unlock;
1071 }
1072
1073 return do_writepage(page, len);
1074
1075out_unlock:
1076 unlock_page(page);
1077 return err;
1078}
1079
1080/**
1081 * do_attr_changes - change inode attributes.
1082 * @inode: inode to change attributes for
1083 * @attr: describes attributes to change
1084 */
1085static void do_attr_changes(struct inode *inode, const struct iattr *attr)
1086{
1087 if (attr->ia_valid & ATTR_UID)
1088 inode->i_uid = attr->ia_uid;
1089 if (attr->ia_valid & ATTR_GID)
1090 inode->i_gid = attr->ia_gid;
1091 if (attr->ia_valid & ATTR_ATIME)
1092 inode->i_atime = timespec_trunc(attr->ia_atime,
1093 inode->i_sb->s_time_gran);
1094 if (attr->ia_valid & ATTR_MTIME)
1095 inode->i_mtime = timespec_trunc(attr->ia_mtime,
1096 inode->i_sb->s_time_gran);
1097 if (attr->ia_valid & ATTR_CTIME)
1098 inode->i_ctime = timespec_trunc(attr->ia_ctime,
1099 inode->i_sb->s_time_gran);
1100 if (attr->ia_valid & ATTR_MODE) {
1101 umode_t mode = attr->ia_mode;
1102
1103 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
1104 mode &= ~S_ISGID;
1105 inode->i_mode = mode;
1106 }
1107}
1108
1109/**
1110 * do_truncation - truncate an inode.
1111 * @c: UBIFS file-system description object
1112 * @inode: inode to truncate
1113 * @attr: inode attribute changes description
1114 *
1115 * This function implements VFS '->setattr()' call when the inode is truncated
1116 * to a smaller size. Returns zero in case of success and a negative error code
1117 * in case of failure.
1118 */
1119static int do_truncation(struct ubifs_info *c, struct inode *inode,
1120 const struct iattr *attr)
1121{
1122 int err;
1123 struct ubifs_budget_req req;
1124 loff_t old_size = inode->i_size, new_size = attr->ia_size;
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001125 int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001126 struct ubifs_inode *ui = ubifs_inode(inode);
1127
1128 dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size);
1129 memset(&req, 0, sizeof(struct ubifs_budget_req));
1130
1131 /*
1132 * If this is truncation to a smaller size, and we do not truncate on a
1133 * block boundary, budget for changing one data block, because the last
1134 * block will be re-written.
1135 */
1136 if (new_size & (UBIFS_BLOCK_SIZE - 1))
1137 req.dirtied_page = 1;
1138
1139 req.dirtied_ino = 1;
1140 /* A funny way to budget for truncation node */
1141 req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ;
1142 err = ubifs_budget_space(c, &req);
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001143 if (err) {
1144 /*
1145 * Treat truncations to zero as deletion and always allow them,
1146 * just like we do for '->unlink()'.
1147 */
1148 if (new_size || err != -ENOSPC)
1149 return err;
1150 budgeted = 0;
1151 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001152
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001153 truncate_setsize(inode, new_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001154
1155 if (offset) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001156 pgoff_t index = new_size >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001157 struct page *page;
1158
1159 page = find_lock_page(inode->i_mapping, index);
1160 if (page) {
1161 if (PageDirty(page)) {
1162 /*
1163 * 'ubifs_jnl_truncate()' will try to truncate
1164 * the last data node, but it contains
1165 * out-of-date data because the page is dirty.
1166 * Write the page now, so that
1167 * 'ubifs_jnl_truncate()' will see an already
1168 * truncated (and up to date) data node.
1169 */
1170 ubifs_assert(PagePrivate(page));
1171
1172 clear_page_dirty_for_io(page);
1173 if (UBIFS_BLOCKS_PER_PAGE_SHIFT)
1174 offset = new_size &
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001175 (PAGE_SIZE - 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001176 err = do_writepage(page, offset);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001177 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001178 if (err)
1179 goto out_budg;
1180 /*
1181 * We could now tell 'ubifs_jnl_truncate()' not
1182 * to read the last block.
1183 */
1184 } else {
1185 /*
1186 * We could 'kmap()' the page and pass the data
1187 * to 'ubifs_jnl_truncate()' to save it from
1188 * having to read it.
1189 */
1190 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001191 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001192 }
1193 }
1194 }
1195
1196 mutex_lock(&ui->ui_mutex);
1197 ui->ui_size = inode->i_size;
1198 /* Truncation changes inode [mc]time */
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001199 inode->i_mtime = inode->i_ctime = current_time(inode);
Artem Bityutskiy873a64c2009-09-01 17:06:43 +03001200 /* Other attributes may be changed at the same time as well */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001201 do_attr_changes(inode, attr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001202 err = ubifs_jnl_truncate(c, inode, old_size, new_size);
1203 mutex_unlock(&ui->ui_mutex);
Artem Bityutskiy873a64c2009-09-01 17:06:43 +03001204
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001205out_budg:
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001206 if (budgeted)
1207 ubifs_release_budget(c, &req);
1208 else {
Artem Bityutskiyb1375452011-03-29 18:04:05 +03001209 c->bi.nospace = c->bi.nospace_rp = 0;
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001210 smp_wmb();
1211 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001212 return err;
1213}
1214
1215/**
1216 * do_setattr - change inode attributes.
1217 * @c: UBIFS file-system description object
1218 * @inode: inode to change attributes for
1219 * @attr: inode attribute changes description
1220 *
1221 * This function implements VFS '->setattr()' call for all cases except
1222 * truncations to smaller size. Returns zero in case of success and a negative
1223 * error code in case of failure.
1224 */
1225static int do_setattr(struct ubifs_info *c, struct inode *inode,
1226 const struct iattr *attr)
1227{
1228 int err, release;
1229 loff_t new_size = attr->ia_size;
1230 struct ubifs_inode *ui = ubifs_inode(inode);
1231 struct ubifs_budget_req req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001232 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001233
1234 err = ubifs_budget_space(c, &req);
1235 if (err)
1236 return err;
1237
1238 if (attr->ia_valid & ATTR_SIZE) {
1239 dbg_gen("size %lld -> %lld", inode->i_size, new_size);
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001240 truncate_setsize(inode, new_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001241 }
1242
1243 mutex_lock(&ui->ui_mutex);
1244 if (attr->ia_valid & ATTR_SIZE) {
1245 /* Truncation changes inode [mc]time */
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001246 inode->i_mtime = inode->i_ctime = current_time(inode);
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001247 /* 'truncate_setsize()' changed @i_size, update @ui_size */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001248 ui->ui_size = inode->i_size;
1249 }
1250
1251 do_attr_changes(inode, attr);
1252
1253 release = ui->dirty;
1254 if (attr->ia_valid & ATTR_SIZE)
1255 /*
1256 * Inode length changed, so we have to make sure
1257 * @I_DIRTY_DATASYNC is set.
1258 */
1259 __mark_inode_dirty(inode, I_DIRTY_SYNC | I_DIRTY_DATASYNC);
1260 else
1261 mark_inode_dirty_sync(inode);
1262 mutex_unlock(&ui->ui_mutex);
1263
1264 if (release)
1265 ubifs_release_budget(c, &req);
1266 if (IS_SYNC(inode))
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001267 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001268 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001269}
1270
1271int ubifs_setattr(struct dentry *dentry, struct iattr *attr)
1272{
1273 int err;
David Howells2b0143b2015-03-17 22:25:59 +00001274 struct inode *inode = d_inode(dentry);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001275 struct ubifs_info *c = inode->i_sb->s_fs_info;
1276
Artem Bityutskiy7d32c2b2008-07-18 18:54:29 +03001277 dbg_gen("ino %lu, mode %#x, ia_valid %#x",
1278 inode->i_ino, inode->i_mode, attr->ia_valid);
Jan Kara31051c82016-05-26 16:55:18 +02001279 err = setattr_prepare(dentry, attr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001280 if (err)
1281 return err;
1282
Artem Bityutskiyd808efb2011-05-31 18:14:38 +03001283 err = dbg_check_synced_i_size(c, inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001284 if (err)
1285 return err;
1286
Eric Biggers4afb9992017-06-13 16:47:55 -07001287 if (ubifs_crypt_is_encrypted(inode) && (attr->ia_valid & ATTR_SIZE)) {
1288 err = fscrypt_get_encryption_info(inode);
1289 if (err)
1290 return err;
1291 if (!fscrypt_has_encryption_key(inode))
1292 return -ENOKEY;
1293 }
1294
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001295 if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size < inode->i_size)
1296 /* Truncation to a smaller size */
1297 err = do_truncation(c, inode, attr);
1298 else
1299 err = do_setattr(c, inode, attr);
1300
1301 return err;
1302}
1303
Lukas Czernerd47992f2013-05-21 23:17:23 -04001304static void ubifs_invalidatepage(struct page *page, unsigned int offset,
1305 unsigned int length)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001306{
1307 struct inode *inode = page->mapping->host;
1308 struct ubifs_info *c = inode->i_sb->s_fs_info;
1309
1310 ubifs_assert(PagePrivate(page));
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001311 if (offset || length < PAGE_SIZE)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001312 /* Partial page remains dirty */
1313 return;
1314
1315 if (PageChecked(page))
1316 release_new_page_budget(c);
1317 else
1318 release_existing_page_budget(c);
1319
1320 atomic_long_dec(&c->dirty_pg_cnt);
1321 ClearPagePrivate(page);
1322 ClearPageChecked(page);
1323}
1324
Josef Bacik02c24a82011-07-16 20:44:56 -04001325int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001326{
Christoph Hellwig7ea80852010-05-26 17:53:25 +02001327 struct inode *inode = file->f_mapping->host;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001328 struct ubifs_info *c = inode->i_sb->s_fs_info;
1329 int err;
1330
1331 dbg_gen("syncing inode %lu", inode->i_ino);
1332
Artem Bityutskiy3b2f9a02011-04-21 15:11:33 +03001333 if (c->ro_mount)
1334 /*
1335 * For some really strange reasons VFS does not filter out
1336 * 'fsync()' for R/O mounted file-systems as per 2.6.39.
1337 */
Artem Bityutskiy78530bf2011-04-13 10:31:52 +03001338 return 0;
1339
Josef Bacik02c24a82011-07-16 20:44:56 -04001340 err = filemap_write_and_wait_range(inode->i_mapping, start, end);
1341 if (err)
1342 return err;
Al Viro59551022016-01-22 15:40:57 -05001343 inode_lock(inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001344
1345 /* Synchronize the inode unless this is a 'datasync()' call. */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001346 if (!datasync || (inode->i_state & I_DIRTY_DATASYNC)) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001347 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001348 if (err)
Josef Bacik02c24a82011-07-16 20:44:56 -04001349 goto out;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001350 }
1351
1352 /*
1353 * Nodes related to this inode may still sit in a write-buffer. Flush
1354 * them.
1355 */
1356 err = ubifs_sync_wbufs_by_inode(c, inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001357out:
Al Viro59551022016-01-22 15:40:57 -05001358 inode_unlock(inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001359 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001360}
1361
1362/**
1363 * mctime_update_needed - check if mtime or ctime update is needed.
1364 * @inode: the inode to do the check for
1365 * @now: current time
1366 *
1367 * This helper function checks if the inode mtime/ctime should be updated or
1368 * not. If current values of the time-stamps are within the UBIFS inode time
1369 * granularity, they are not updated. This is an optimization.
1370 */
1371static inline int mctime_update_needed(const struct inode *inode,
1372 const struct timespec *now)
1373{
1374 if (!timespec_equal(&inode->i_mtime, now) ||
1375 !timespec_equal(&inode->i_ctime, now))
1376 return 1;
1377 return 0;
1378}
1379
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001380#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1381/**
1382 * ubifs_update_time - update time of inode.
1383 * @inode: inode to update
1384 *
1385 * This function updates time of the inode.
1386 */
1387int ubifs_update_time(struct inode *inode, struct timespec *time,
1388 int flags)
1389{
1390 struct ubifs_inode *ui = ubifs_inode(inode);
1391 struct ubifs_info *c = inode->i_sb->s_fs_info;
1392 struct ubifs_budget_req req = { .dirtied_ino = 1,
1393 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
1394 int iflags = I_DIRTY_TIME;
1395 int err, release;
1396
1397 err = ubifs_budget_space(c, &req);
1398 if (err)
1399 return err;
1400
1401 mutex_lock(&ui->ui_mutex);
1402 if (flags & S_ATIME)
1403 inode->i_atime = *time;
1404 if (flags & S_CTIME)
1405 inode->i_ctime = *time;
1406 if (flags & S_MTIME)
1407 inode->i_mtime = *time;
1408
1409 if (!(inode->i_sb->s_flags & MS_LAZYTIME))
1410 iflags |= I_DIRTY_SYNC;
1411
1412 release = ui->dirty;
1413 __mark_inode_dirty(inode, iflags);
1414 mutex_unlock(&ui->ui_mutex);
1415 if (release)
1416 ubifs_release_budget(c, &req);
1417 return 0;
1418}
1419#endif
1420
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001421/**
Julia Lawallec037df2016-10-01 22:53:11 +02001422 * update_mctime - update mtime and ctime of an inode.
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001423 * @inode: inode to update
1424 *
1425 * This function updates mtime and ctime of the inode if it is not equivalent to
1426 * current time. Returns zero in case of success and a negative error code in
1427 * case of failure.
1428 */
Al Virof5674c32014-04-03 14:00:23 -04001429static int update_mctime(struct inode *inode)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001430{
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001431 struct timespec now = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001432 struct ubifs_inode *ui = ubifs_inode(inode);
Al Virof5674c32014-04-03 14:00:23 -04001433 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001434
1435 if (mctime_update_needed(inode, &now)) {
1436 int err, release;
1437 struct ubifs_budget_req req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001438 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001439
1440 err = ubifs_budget_space(c, &req);
1441 if (err)
1442 return err;
1443
1444 mutex_lock(&ui->ui_mutex);
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001445 inode->i_mtime = inode->i_ctime = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001446 release = ui->dirty;
1447 mark_inode_dirty_sync(inode);
1448 mutex_unlock(&ui->ui_mutex);
1449 if (release)
1450 ubifs_release_budget(c, &req);
1451 }
1452
1453 return 0;
1454}
1455
Al Virof5674c32014-04-03 14:00:23 -04001456static ssize_t ubifs_write_iter(struct kiocb *iocb, struct iov_iter *from)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001457{
Al Virof5674c32014-04-03 14:00:23 -04001458 int err = update_mctime(file_inode(iocb->ki_filp));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001459 if (err)
1460 return err;
1461
Al Virof5674c32014-04-03 14:00:23 -04001462 return generic_file_write_iter(iocb, from);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001463}
1464
1465static int ubifs_set_page_dirty(struct page *page)
1466{
1467 int ret;
1468
1469 ret = __set_page_dirty_nobuffers(page);
1470 /*
1471 * An attempt to dirty a page without budgeting for it - should not
1472 * happen.
1473 */
1474 ubifs_assert(ret == 0);
1475 return ret;
1476}
1477
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001478#ifdef CONFIG_MIGRATION
1479static int ubifs_migrate_page(struct address_space *mapping,
1480 struct page *newpage, struct page *page, enum migrate_mode mode)
1481{
1482 int rc;
1483
1484 rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0);
1485 if (rc != MIGRATEPAGE_SUCCESS)
1486 return rc;
1487
1488 if (PagePrivate(page)) {
1489 ClearPagePrivate(page);
1490 SetPagePrivate(newpage);
1491 }
1492
1493 migrate_page_copy(newpage, page);
1494 return MIGRATEPAGE_SUCCESS;
1495}
1496#endif
1497
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001498static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags)
1499{
1500 /*
1501 * An attempt to release a dirty page without budgeting for it - should
1502 * not happen.
1503 */
1504 if (PageWriteback(page))
1505 return 0;
1506 ubifs_assert(PagePrivate(page));
1507 ubifs_assert(0);
1508 ClearPagePrivate(page);
1509 ClearPageChecked(page);
1510 return 1;
1511}
1512
1513/*
Artem Bityutskiyc4361572011-03-25 15:27:40 +02001514 * mmap()d file has taken write protection fault and is being made writable.
1515 * UBIFS must ensure page is budgeted for.
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001516 */
Dave Jiang11bac802017-02-24 14:56:41 -08001517static int ubifs_vm_page_mkwrite(struct vm_fault *vmf)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001518{
Nick Pigginc2ec1752009-03-31 15:23:21 -07001519 struct page *page = vmf->page;
Dave Jiang11bac802017-02-24 14:56:41 -08001520 struct inode *inode = file_inode(vmf->vma->vm_file);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001521 struct ubifs_info *c = inode->i_sb->s_fs_info;
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001522 struct timespec now = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001523 struct ubifs_budget_req req = { .new_page = 1 };
1524 int err, update_time;
1525
1526 dbg_gen("ino %lu, pg %lu, i_size %lld", inode->i_ino, page->index,
1527 i_size_read(inode));
Artem Bityutskiy2ef13292010-09-19 18:34:26 +03001528 ubifs_assert(!c->ro_media && !c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001529
Artem Bityutskiy2680d722010-09-17 16:44:28 +03001530 if (unlikely(c->ro_error))
Nick Pigginc2ec1752009-03-31 15:23:21 -07001531 return VM_FAULT_SIGBUS; /* -EROFS */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001532
1533 /*
1534 * We have not locked @page so far so we may budget for changing the
1535 * page. Note, we cannot do this after we locked the page, because
1536 * budgeting may cause write-back which would cause deadlock.
1537 *
1538 * At the moment we do not know whether the page is dirty or not, so we
1539 * assume that it is not and budget for a new page. We could look at
1540 * the @PG_private flag and figure this out, but we may race with write
1541 * back and the page state may change by the time we lock it, so this
1542 * would need additional care. We do not bother with this at the
1543 * moment, although it might be good idea to do. Instead, we allocate
1544 * budget for a new page and amend it later on if the page was in fact
1545 * dirty.
1546 *
1547 * The budgeting-related logic of this function is similar to what we
1548 * do in 'ubifs_write_begin()' and 'ubifs_write_end()'. Glance there
1549 * for more comments.
1550 */
1551 update_time = mctime_update_needed(inode, &now);
1552 if (update_time)
1553 /*
1554 * We have to change inode time stamp which requires extra
1555 * budgeting.
1556 */
1557 req.dirtied_ino = 1;
1558
1559 err = ubifs_budget_space(c, &req);
1560 if (unlikely(err)) {
1561 if (err == -ENOSPC)
Sheng Yong235c3622015-03-20 10:39:42 +00001562 ubifs_warn(c, "out of space for mmapped file (inode number %lu)",
Artem Bityutskiy79fda512012-08-27 13:34:09 +03001563 inode->i_ino);
Nick Pigginc2ec1752009-03-31 15:23:21 -07001564 return VM_FAULT_SIGBUS;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001565 }
1566
1567 lock_page(page);
1568 if (unlikely(page->mapping != inode->i_mapping ||
1569 page_offset(page) > i_size_read(inode))) {
1570 /* Page got truncated out from underneath us */
1571 err = -EINVAL;
1572 goto out_unlock;
1573 }
1574
1575 if (PagePrivate(page))
1576 release_new_page_budget(c);
1577 else {
1578 if (!PageChecked(page))
1579 ubifs_convert_page_budget(c);
1580 SetPagePrivate(page);
1581 atomic_long_inc(&c->dirty_pg_cnt);
1582 __set_page_dirty_nobuffers(page);
1583 }
1584
1585 if (update_time) {
1586 int release;
1587 struct ubifs_inode *ui = ubifs_inode(inode);
1588
1589 mutex_lock(&ui->ui_mutex);
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001590 inode->i_mtime = inode->i_ctime = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001591 release = ui->dirty;
1592 mark_inode_dirty_sync(inode);
1593 mutex_unlock(&ui->ui_mutex);
1594 if (release)
1595 ubifs_release_dirty_inode_budget(c, ui);
1596 }
1597
Jan Kara182dcfd2013-02-21 16:42:59 -08001598 wait_for_stable_page(page);
hujianyang691a7c62014-04-30 14:06:06 +08001599 return VM_FAULT_LOCKED;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001600
1601out_unlock:
1602 unlock_page(page);
1603 ubifs_release_budget(c, &req);
Nick Pigginc2ec1752009-03-31 15:23:21 -07001604 if (err)
1605 err = VM_FAULT_SIGBUS;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001606 return err;
1607}
1608
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +04001609static const struct vm_operations_struct ubifs_file_vm_ops = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001610 .fault = filemap_fault,
Kirill A. Shutemovf1820362014-04-07 15:37:19 -07001611 .map_pages = filemap_map_pages,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001612 .page_mkwrite = ubifs_vm_page_mkwrite,
1613};
1614
1615static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1616{
1617 int err;
1618
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001619 err = generic_file_mmap(file, vma);
1620 if (err)
1621 return err;
1622 vma->vm_ops = &ubifs_file_vm_ops;
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001623#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1624 file_accessed(file);
1625#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001626 return 0;
1627}
1628
Richard Weinbergera79bff22016-09-29 18:00:57 +02001629static int ubifs_file_open(struct inode *inode, struct file *filp)
1630{
1631 int ret;
1632 struct dentry *dir;
1633 struct ubifs_info *c = inode->i_sb->s_fs_info;
1634
1635 if (ubifs_crypt_is_encrypted(inode)) {
1636 ret = fscrypt_get_encryption_info(inode);
1637 if (ret)
1638 return -EACCES;
1639 if (!fscrypt_has_encryption_key(inode))
1640 return -ENOKEY;
1641 }
1642
1643 dir = dget_parent(file_dentry(filp));
1644 if (ubifs_crypt_is_encrypted(d_inode(dir)) &&
1645 !fscrypt_has_permitted_context(d_inode(dir), inode)) {
1646 ubifs_err(c, "Inconsistent encryption contexts: %lu/%lu",
1647 (unsigned long) d_inode(dir)->i_ino,
1648 (unsigned long) inode->i_ino);
1649 dput(dir);
1650 ubifs_ro_mode(c, -EPERM);
1651 return -EPERM;
1652 }
1653 dput(dir);
1654
1655 return 0;
1656}
1657
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001658static const char *ubifs_get_link(struct dentry *dentry,
1659 struct inode *inode,
1660 struct delayed_call *done)
1661{
1662 int err;
1663 struct fscrypt_symlink_data *sd;
1664 struct ubifs_inode *ui = ubifs_inode(inode);
1665 struct fscrypt_str cstr;
1666 struct fscrypt_str pstr;
1667
1668 if (!ubifs_crypt_is_encrypted(inode))
1669 return ui->data;
1670
1671 if (!dentry)
1672 return ERR_PTR(-ECHILD);
1673
1674 err = fscrypt_get_encryption_info(inode);
1675 if (err)
1676 return ERR_PTR(err);
1677
1678 sd = (struct fscrypt_symlink_data *)ui->data;
1679 cstr.name = sd->encrypted_path;
1680 cstr.len = le16_to_cpu(sd->len);
1681
1682 if (cstr.len == 0)
1683 return ERR_PTR(-ENOENT);
1684
1685 if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > ui->data_len)
1686 return ERR_PTR(-EIO);
1687
1688 err = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
1689 if (err)
1690 return ERR_PTR(err);
1691
1692 err = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
1693 if (err) {
1694 fscrypt_fname_free_buffer(&pstr);
1695 return ERR_PTR(err);
1696 }
1697
1698 pstr.name[pstr.len] = '\0';
1699
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001700 set_delayed_call(done, kfree_link, pstr.name);
1701 return pstr.name;
1702}
1703
1704
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001705const struct address_space_operations ubifs_file_address_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001706 .readpage = ubifs_readpage,
1707 .writepage = ubifs_writepage,
1708 .write_begin = ubifs_write_begin,
1709 .write_end = ubifs_write_end,
1710 .invalidatepage = ubifs_invalidatepage,
1711 .set_page_dirty = ubifs_set_page_dirty,
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001712#ifdef CONFIG_MIGRATION
1713 .migratepage = ubifs_migrate_page,
1714#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001715 .releasepage = ubifs_releasepage,
1716};
1717
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001718const struct inode_operations ubifs_file_inode_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001719 .setattr = ubifs_setattr,
1720 .getattr = ubifs_getattr,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001721 .listxattr = ubifs_listxattr,
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001722#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1723 .update_time = ubifs_update_time,
1724#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001725};
1726
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001727const struct inode_operations ubifs_symlink_inode_operations = {
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001728 .get_link = ubifs_get_link,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001729 .setattr = ubifs_setattr,
1730 .getattr = ubifs_getattr,
Subodh Nijsure895d9db2014-10-31 13:50:29 -05001731 .listxattr = ubifs_listxattr,
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001732#ifdef CONFIG_UBIFS_ATIME_SUPPORT
1733 .update_time = ubifs_update_time,
1734#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001735};
1736
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001737const struct file_operations ubifs_file_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001738 .llseek = generic_file_llseek,
Al Viroaad4f8b2014-04-02 14:33:16 -04001739 .read_iter = generic_file_read_iter,
Al Virof5674c32014-04-03 14:00:23 -04001740 .write_iter = ubifs_write_iter,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001741 .mmap = ubifs_file_mmap,
1742 .fsync = ubifs_fsync,
1743 .unlocked_ioctl = ubifs_ioctl,
1744 .splice_read = generic_file_splice_read,
Al Viro8d020762014-04-05 04:27:08 -04001745 .splice_write = iter_file_splice_write,
Richard Weinbergera79bff22016-09-29 18:00:57 +02001746 .open = ubifs_file_open,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001747#ifdef CONFIG_COMPAT
1748 .compat_ioctl = ubifs_compat_ioctl,
1749#endif
1750};