blob: 49fe062ce45ec2f0c675582d0c0bcf9ac3261995 [file] [log] [blame]
Thomas Gleixner2b27bdc2019-05-29 16:57:50 -07001// SPDX-License-Identifier: GPL-2.0-only
Artem Bityutskiy1e517642008-07-14 19:08:37 +03002/*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation.
6 *
Artem Bityutskiy1e517642008-07-14 19:08:37 +03007 * Authors: Artem Bityutskiy (Битюцкий Артём)
8 * Adrian Hunter
9 */
10
11/*
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030012 * This file implements VFS file and inode operations for regular files, device
Artem Bityutskiy1e517642008-07-14 19:08:37 +030013 * nodes and symlinks as well as address space operations.
14 *
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030015 * UBIFS uses 2 page flags: @PG_private and @PG_checked. @PG_private is set if
16 * the page is dirty and is used for optimization purposes - dirty pages are
17 * not budgeted so the flag shows that 'ubifs_write_end()' should not release
18 * the budget for this page. The @PG_checked flag is set if full budgeting is
19 * required for the page e.g., when it corresponds to a file hole or it is
20 * beyond the file size. The budgeting is done in 'ubifs_write_begin()', because
21 * it is OK to fail in this function, and the budget is released in
22 * 'ubifs_write_end()'. So the @PG_private and @PG_checked flags carry
23 * information about how the page was budgeted, to make it possible to release
24 * the budget properly.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030025 *
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030026 * A thing to keep in mind: inode @i_mutex is locked in most VFS operations we
27 * implement. However, this is not true for 'ubifs_writepage()', which may be
Artem Bityutskiy5c57f202012-07-25 18:12:14 +030028 * called with @i_mutex unlocked. For example, when flusher thread is doing
29 * background write-back, it calls 'ubifs_writepage()' with unlocked @i_mutex.
30 * At "normal" work-paths the @i_mutex is locked in 'ubifs_writepage()', e.g.
31 * in the "sys_write -> alloc_pages -> direct reclaim path". So, in
32 * 'ubifs_writepage()' we are only guaranteed that the page is locked.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030033 *
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030034 * Similarly, @i_mutex is not always locked in 'ubifs_readpage()', e.g., the
35 * read-ahead path does not lock it ("sys_read -> generic_file_aio_read ->
Christoph Hellwigeaff8072009-12-17 14:25:01 +010036 * ondemand_readahead -> readpage"). In case of readahead, @I_SYNC flag is not
Artem Bityutskiy873a64c2009-09-01 17:06:43 +030037 * set as well. However, UBIFS disables readahead.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030038 */
39
40#include "ubifs.h"
41#include <linux/mount.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090042#include <linux/slab.h>
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +020043#include <linux/migrate.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030044
45static int read_block(struct inode *inode, void *addr, unsigned int block,
46 struct ubifs_data_node *dn)
47{
48 struct ubifs_info *c = inode->i_sb->s_fs_info;
49 int err, len, out_len;
50 union ubifs_key key;
51 unsigned int dlen;
52
53 data_key_init(c, &key, inode->i_ino, block);
54 err = ubifs_tnc_lookup(c, &key, dn);
55 if (err) {
56 if (err == -ENOENT)
57 /* Not found, so it must be a hole */
58 memset(addr, 0, UBIFS_BLOCK_SIZE);
59 return err;
60 }
61
Richard Weinberger6eb61d52018-07-12 13:01:57 +020062 ubifs_assert(c, le64_to_cpu(dn->ch.sqnum) >
Artem Bityutskiyf92b9822008-12-28 11:34:26 +020063 ubifs_inode(inode)->creat_sqnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +030064 len = le32_to_cpu(dn->size);
65 if (len <= 0 || len > UBIFS_BLOCK_SIZE)
66 goto dump;
67
68 dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
Richard Weinberger77999532016-09-29 22:20:19 +020069
Eric Biggers50d9fad2019-12-09 13:27:21 -080070 if (IS_ENCRYPTED(inode)) {
Richard Weinberger77999532016-09-29 22:20:19 +020071 err = ubifs_decrypt(inode, dn, &dlen, block);
72 if (err)
73 goto dump;
74 }
75
Artem Bityutskiy1e517642008-07-14 19:08:37 +030076 out_len = UBIFS_BLOCK_SIZE;
Sheng Yong235c3622015-03-20 10:39:42 +000077 err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
Artem Bityutskiy1e517642008-07-14 19:08:37 +030078 le16_to_cpu(dn->compr_type));
79 if (err || len != out_len)
80 goto dump;
81
82 /*
83 * Data length can be less than a full block, even for blocks that are
84 * not the last in the file (e.g., as a result of making a hole and
85 * appending data). Ensure that the remainder is zeroed out.
86 */
87 if (len < UBIFS_BLOCK_SIZE)
88 memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
89
90 return 0;
91
92dump:
Sheng Yong235c3622015-03-20 10:39:42 +000093 ubifs_err(c, "bad data node (block %u, inode %lu)",
Artem Bityutskiy1e517642008-07-14 19:08:37 +030094 block, inode->i_ino);
Artem Bityutskiyedf6be22012-05-16 19:15:56 +030095 ubifs_dump_node(c, dn);
Artem Bityutskiy1e517642008-07-14 19:08:37 +030096 return -EINVAL;
97}
98
99static int do_readpage(struct page *page)
100{
101 void *addr;
102 int err = 0, i;
103 unsigned int block, beyond;
104 struct ubifs_data_node *dn;
105 struct inode *inode = page->mapping->host;
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200106 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300107 loff_t i_size = i_size_read(inode);
108
109 dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
110 inode->i_ino, page->index, i_size, page->flags);
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200111 ubifs_assert(c, !PageChecked(page));
112 ubifs_assert(c, !PagePrivate(page));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300113
114 addr = kmap(page);
115
116 block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
117 beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
118 if (block >= beyond) {
119 /* Reading beyond inode */
120 SetPageChecked(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300121 memset(addr, 0, PAGE_SIZE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300122 goto out;
123 }
124
125 dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
126 if (!dn) {
127 err = -ENOMEM;
128 goto error;
129 }
130
131 i = 0;
132 while (1) {
133 int ret;
134
135 if (block >= beyond) {
136 /* Reading beyond inode */
137 err = -ENOENT;
138 memset(addr, 0, UBIFS_BLOCK_SIZE);
139 } else {
140 ret = read_block(inode, addr, block, dn);
141 if (ret) {
142 err = ret;
143 if (err != -ENOENT)
144 break;
Adrian Huntered382d52008-09-05 16:17:42 +0300145 } else if (block + 1 == beyond) {
146 int dlen = le32_to_cpu(dn->size);
147 int ilen = i_size & (UBIFS_BLOCK_SIZE - 1);
148
149 if (ilen && ilen < dlen)
150 memset(addr + ilen, 0, dlen - ilen);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300151 }
152 }
153 if (++i >= UBIFS_BLOCKS_PER_PAGE)
154 break;
155 block += 1;
156 addr += UBIFS_BLOCK_SIZE;
157 }
158 if (err) {
Sheng Yong235c3622015-03-20 10:39:42 +0000159 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300160 if (err == -ENOENT) {
161 /* Not found, so it must be a hole */
162 SetPageChecked(page);
163 dbg_gen("hole");
164 goto out_free;
165 }
Sheng Yong235c3622015-03-20 10:39:42 +0000166 ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300167 page->index, inode->i_ino, err);
168 goto error;
169 }
170
171out_free:
172 kfree(dn);
173out:
174 SetPageUptodate(page);
175 ClearPageError(page);
176 flush_dcache_page(page);
177 kunmap(page);
178 return 0;
179
180error:
181 kfree(dn);
182 ClearPageUptodate(page);
183 SetPageError(page);
184 flush_dcache_page(page);
185 kunmap(page);
186 return err;
187}
188
189/**
190 * release_new_page_budget - release budget of a new page.
191 * @c: UBIFS file-system description object
192 *
193 * This is a helper function which releases budget corresponding to the budget
194 * of one new page of data.
195 */
196static void release_new_page_budget(struct ubifs_info *c)
197{
198 struct ubifs_budget_req req = { .recalculate = 1, .new_page = 1 };
199
200 ubifs_release_budget(c, &req);
201}
202
203/**
204 * release_existing_page_budget - release budget of an existing page.
205 * @c: UBIFS file-system description object
206 *
207 * This is a helper function which releases budget corresponding to the budget
208 * of changing one one page of data which already exists on the flash media.
209 */
210static void release_existing_page_budget(struct ubifs_info *c)
211{
Artem Bityutskiyb1375452011-03-29 18:04:05 +0300212 struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget};
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300213
214 ubifs_release_budget(c, &req);
215}
216
217static int write_begin_slow(struct address_space *mapping,
Nick Piggin54566b22009-01-04 12:00:53 -0800218 loff_t pos, unsigned len, struct page **pagep,
219 unsigned flags)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300220{
221 struct inode *inode = mapping->host;
222 struct ubifs_info *c = inode->i_sb->s_fs_info;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300223 pgoff_t index = pos >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300224 struct ubifs_budget_req req = { .new_page = 1 };
225 int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
226 struct page *page;
227
228 dbg_gen("ino %lu, pos %llu, len %u, i_size %lld",
229 inode->i_ino, pos, len, inode->i_size);
230
231 /*
232 * At the slow path we have to budget before locking the page, because
233 * budgeting may force write-back, which would wait on locked pages and
234 * deadlock if we had the page locked. At this point we do not know
235 * anything about the page, so assume that this is a new page which is
236 * written to a hole. This corresponds to largest budget. Later the
237 * budget will be amended if this is not true.
238 */
239 if (appending)
240 /* We are appending data, budget for inode change */
241 req.dirtied_ino = 1;
242
243 err = ubifs_budget_space(c, &req);
244 if (unlikely(err))
245 return err;
246
Nick Piggin54566b22009-01-04 12:00:53 -0800247 page = grab_cache_page_write_begin(mapping, index, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300248 if (unlikely(!page)) {
249 ubifs_release_budget(c, &req);
250 return -ENOMEM;
251 }
252
253 if (!PageUptodate(page)) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300254 if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300255 SetPageChecked(page);
256 else {
257 err = do_readpage(page);
258 if (err) {
259 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300260 put_page(page);
Artem Bityutskiy789c8992014-10-20 17:52:31 +0300261 ubifs_release_budget(c, &req);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300262 return err;
263 }
264 }
265
266 SetPageUptodate(page);
267 ClearPageError(page);
268 }
269
270 if (PagePrivate(page))
271 /*
272 * The page is dirty, which means it was budgeted twice:
273 * o first time the budget was allocated by the task which
274 * made the page dirty and set the PG_private flag;
275 * o and then we budgeted for it for the second time at the
276 * very beginning of this function.
277 *
278 * So what we have to do is to release the page budget we
279 * allocated.
280 */
281 release_new_page_budget(c);
282 else if (!PageChecked(page))
283 /*
284 * We are changing a page which already exists on the media.
285 * This means that changing the page does not make the amount
286 * of indexing information larger, and this part of the budget
287 * which we have already acquired may be released.
288 */
289 ubifs_convert_page_budget(c);
290
291 if (appending) {
292 struct ubifs_inode *ui = ubifs_inode(inode);
293
294 /*
295 * 'ubifs_write_end()' is optimized from the fast-path part of
296 * 'ubifs_write_begin()' and expects the @ui_mutex to be locked
297 * if data is appended.
298 */
299 mutex_lock(&ui->ui_mutex);
300 if (ui->dirty)
301 /*
302 * The inode is dirty already, so we may free the
303 * budget we allocated.
304 */
305 ubifs_release_dirty_inode_budget(c, ui);
306 }
307
308 *pagep = page;
309 return 0;
310}
311
312/**
313 * allocate_budget - allocate budget for 'ubifs_write_begin()'.
314 * @c: UBIFS file-system description object
315 * @page: page to allocate budget for
316 * @ui: UBIFS inode object the page belongs to
317 * @appending: non-zero if the page is appended
318 *
319 * This is a helper function for 'ubifs_write_begin()' which allocates budget
320 * for the operation. The budget is allocated differently depending on whether
321 * this is appending, whether the page is dirty or not, and so on. This
322 * function leaves the @ui->ui_mutex locked in case of appending. Returns zero
323 * in case of success and %-ENOSPC in case of failure.
324 */
325static int allocate_budget(struct ubifs_info *c, struct page *page,
326 struct ubifs_inode *ui, int appending)
327{
328 struct ubifs_budget_req req = { .fast = 1 };
329
330 if (PagePrivate(page)) {
331 if (!appending)
332 /*
333 * The page is dirty and we are not appending, which
334 * means no budget is needed at all.
335 */
336 return 0;
337
338 mutex_lock(&ui->ui_mutex);
339 if (ui->dirty)
340 /*
341 * The page is dirty and we are appending, so the inode
342 * has to be marked as dirty. However, it is already
343 * dirty, so we do not need any budget. We may return,
344 * but @ui->ui_mutex hast to be left locked because we
345 * should prevent write-back from flushing the inode
346 * and freeing the budget. The lock will be released in
347 * 'ubifs_write_end()'.
348 */
349 return 0;
350
351 /*
352 * The page is dirty, we are appending, the inode is clean, so
353 * we need to budget the inode change.
354 */
355 req.dirtied_ino = 1;
356 } else {
357 if (PageChecked(page))
358 /*
359 * The page corresponds to a hole and does not
360 * exist on the media. So changing it makes
361 * make the amount of indexing information
362 * larger, and we have to budget for a new
363 * page.
364 */
365 req.new_page = 1;
366 else
367 /*
368 * Not a hole, the change will not add any new
369 * indexing information, budget for page
370 * change.
371 */
372 req.dirtied_page = 1;
373
374 if (appending) {
375 mutex_lock(&ui->ui_mutex);
376 if (!ui->dirty)
377 /*
378 * The inode is clean but we will have to mark
379 * it as dirty because we are appending. This
380 * needs a budget.
381 */
382 req.dirtied_ino = 1;
383 }
384 }
385
386 return ubifs_budget_space(c, &req);
387}
388
389/*
390 * This function is called when a page of data is going to be written. Since
391 * the page of data will not necessarily go to the flash straight away, UBIFS
392 * has to reserve space on the media for it, which is done by means of
393 * budgeting.
394 *
395 * This is the hot-path of the file-system and we are trying to optimize it as
396 * much as possible. For this reasons it is split on 2 parts - slow and fast.
397 *
398 * There many budgeting cases:
399 * o a new page is appended - we have to budget for a new page and for
400 * changing the inode; however, if the inode is already dirty, there is
401 * no need to budget for it;
402 * o an existing clean page is changed - we have budget for it; if the page
403 * does not exist on the media (a hole), we have to budget for a new
404 * page; otherwise, we may budget for changing an existing page; the
405 * difference between these cases is that changing an existing page does
406 * not introduce anything new to the FS indexing information, so it does
407 * not grow, and smaller budget is acquired in this case;
408 * o an existing dirty page is changed - no need to budget at all, because
409 * the page budget has been acquired by earlier, when the page has been
410 * marked dirty.
411 *
412 * UBIFS budgeting sub-system may force write-back if it thinks there is no
413 * space to reserve. This imposes some locking restrictions and makes it
414 * impossible to take into account the above cases, and makes it impossible to
415 * optimize budgeting.
416 *
417 * The solution for this is that the fast path of 'ubifs_write_begin()' assumes
418 * there is a plenty of flash space and the budget will be acquired quickly,
419 * without forcing write-back. The slow path does not make this assumption.
420 */
421static int ubifs_write_begin(struct file *file, struct address_space *mapping,
422 loff_t pos, unsigned len, unsigned flags,
423 struct page **pagep, void **fsdata)
424{
425 struct inode *inode = mapping->host;
426 struct ubifs_info *c = inode->i_sb->s_fs_info;
427 struct ubifs_inode *ui = ubifs_inode(inode);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300428 pgoff_t index = pos >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300429 int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
Adrian Hunterf55aa592009-02-23 12:47:25 +0200430 int skipped_read = 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300431 struct page *page;
432
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200433 ubifs_assert(c, ubifs_inode(inode)->ui_size == inode->i_size);
434 ubifs_assert(c, !c->ro_media && !c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300435
Artem Bityutskiy2680d722010-09-17 16:44:28 +0300436 if (unlikely(c->ro_error))
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300437 return -EROFS;
438
439 /* Try out the fast-path part first */
Nick Piggin54566b22009-01-04 12:00:53 -0800440 page = grab_cache_page_write_begin(mapping, index, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300441 if (unlikely(!page))
442 return -ENOMEM;
443
444 if (!PageUptodate(page)) {
445 /* The page is not loaded from the flash */
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300446 if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300447 /*
448 * We change whole page so no need to load it. But we
Artem Bityutskiy6ed09c32011-03-23 10:32:58 +0200449 * do not know whether this page exists on the media or
450 * not, so we assume the latter because it requires
451 * larger budget. The assumption is that it is better
452 * to budget a bit more than to read the page from the
453 * media. Thus, we are setting the @PG_checked flag
454 * here.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300455 */
456 SetPageChecked(page);
Adrian Hunterf55aa592009-02-23 12:47:25 +0200457 skipped_read = 1;
458 } else {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300459 err = do_readpage(page);
460 if (err) {
461 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300462 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300463 return err;
464 }
465 }
466
467 SetPageUptodate(page);
468 ClearPageError(page);
469 }
470
471 err = allocate_budget(c, page, ui, appending);
472 if (unlikely(err)) {
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200473 ubifs_assert(c, err == -ENOSPC);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300474 /*
Adrian Hunterf55aa592009-02-23 12:47:25 +0200475 * If we skipped reading the page because we were going to
476 * write all of it, then it is not up to date.
477 */
478 if (skipped_read) {
479 ClearPageChecked(page);
480 ClearPageUptodate(page);
481 }
482 /*
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300483 * Budgeting failed which means it would have to force
484 * write-back but didn't, because we set the @fast flag in the
485 * request. Write-back cannot be done now, while we have the
486 * page locked, because it would deadlock. Unlock and free
487 * everything and fall-back to slow-path.
488 */
489 if (appending) {
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200490 ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300491 mutex_unlock(&ui->ui_mutex);
492 }
493 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300494 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300495
Nick Piggin54566b22009-01-04 12:00:53 -0800496 return write_begin_slow(mapping, pos, len, pagep, flags);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300497 }
498
499 /*
Artem Bityutskiy873a64c2009-09-01 17:06:43 +0300500 * Whee, we acquired budgeting quickly - without involving
501 * garbage-collection, committing or forcing write-back. We return
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300502 * with @ui->ui_mutex locked if we are appending pages, and unlocked
503 * otherwise. This is an optimization (slightly hacky though).
504 */
505 *pagep = page;
506 return 0;
507
508}
509
510/**
511 * cancel_budget - cancel budget.
512 * @c: UBIFS file-system description object
513 * @page: page to cancel budget for
514 * @ui: UBIFS inode object the page belongs to
515 * @appending: non-zero if the page is appended
516 *
517 * This is a helper function for a page write operation. It unlocks the
518 * @ui->ui_mutex in case of appending.
519 */
520static void cancel_budget(struct ubifs_info *c, struct page *page,
521 struct ubifs_inode *ui, int appending)
522{
523 if (appending) {
524 if (!ui->dirty)
525 ubifs_release_dirty_inode_budget(c, ui);
526 mutex_unlock(&ui->ui_mutex);
527 }
528 if (!PagePrivate(page)) {
529 if (PageChecked(page))
530 release_new_page_budget(c);
531 else
532 release_existing_page_budget(c);
533 }
534}
535
536static int ubifs_write_end(struct file *file, struct address_space *mapping,
537 loff_t pos, unsigned len, unsigned copied,
538 struct page *page, void *fsdata)
539{
540 struct inode *inode = mapping->host;
541 struct ubifs_inode *ui = ubifs_inode(inode);
542 struct ubifs_info *c = inode->i_sb->s_fs_info;
543 loff_t end_pos = pos + len;
544 int appending = !!(end_pos > inode->i_size);
545
546 dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld",
547 inode->i_ino, pos, page->index, len, copied, inode->i_size);
548
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300549 if (unlikely(copied < len && len == PAGE_SIZE)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300550 /*
551 * VFS copied less data to the page that it intended and
552 * declared in its '->write_begin()' call via the @len
553 * argument. If the page was not up-to-date, and @len was
Kirill A. Shutemovea1754a2016-04-01 15:29:48 +0300554 * @PAGE_SIZE, the 'ubifs_write_begin()' function did
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300555 * not load it from the media (for optimization reasons). This
556 * means that part of the page contains garbage. So read the
557 * page now.
558 */
559 dbg_gen("copied %d instead of %d, read page and repeat",
560 copied, len);
561 cancel_budget(c, page, ui, appending);
Artem Bityutskiy6ed09c32011-03-23 10:32:58 +0200562 ClearPageChecked(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300563
564 /*
565 * Return 0 to force VFS to repeat the whole operation, or the
Artem Bityutskiy873a64c2009-09-01 17:06:43 +0300566 * error code if 'do_readpage()' fails.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300567 */
568 copied = do_readpage(page);
569 goto out;
570 }
571
572 if (!PagePrivate(page)) {
573 SetPagePrivate(page);
574 atomic_long_inc(&c->dirty_pg_cnt);
575 __set_page_dirty_nobuffers(page);
576 }
577
578 if (appending) {
579 i_size_write(inode, end_pos);
580 ui->ui_size = end_pos;
581 /*
582 * Note, we do not set @I_DIRTY_PAGES (which means that the
583 * inode has dirty pages), this has been done in
584 * '__set_page_dirty_nobuffers()'.
585 */
586 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200587 ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300588 mutex_unlock(&ui->ui_mutex);
589 }
590
591out:
592 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300593 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300594 return copied;
595}
596
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300597/**
598 * populate_page - copy data nodes into a page for bulk-read.
599 * @c: UBIFS file-system description object
600 * @page: page
601 * @bu: bulk-read information
602 * @n: next zbranch slot
603 *
604 * This function returns %0 on success and a negative error code on failure.
605 */
606static int populate_page(struct ubifs_info *c, struct page *page,
607 struct bu_info *bu, int *n)
608{
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300609 int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300610 struct inode *inode = page->mapping->host;
611 loff_t i_size = i_size_read(inode);
612 unsigned int page_block;
613 void *addr, *zaddr;
614 pgoff_t end_index;
615
616 dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
617 inode->i_ino, page->index, i_size, page->flags);
618
619 addr = zaddr = kmap(page);
620
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300621 end_index = (i_size - 1) >> PAGE_SHIFT;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300622 if (!i_size || page->index > end_index) {
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300623 hole = 1;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300624 memset(addr, 0, PAGE_SIZE);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300625 goto out_hole;
626 }
627
628 page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
629 while (1) {
630 int err, len, out_len, dlen;
631
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300632 if (nn >= bu->cnt) {
633 hole = 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300634 memset(addr, 0, UBIFS_BLOCK_SIZE);
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300635 } else if (key_block(c, &bu->zbranch[nn].key) == page_block) {
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300636 struct ubifs_data_node *dn;
637
638 dn = bu->buf + (bu->zbranch[nn].offs - offs);
639
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200640 ubifs_assert(c, le64_to_cpu(dn->ch.sqnum) >
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300641 ubifs_inode(inode)->creat_sqnum);
642
643 len = le32_to_cpu(dn->size);
644 if (len <= 0 || len > UBIFS_BLOCK_SIZE)
645 goto out_err;
646
647 dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
648 out_len = UBIFS_BLOCK_SIZE;
Richard Weinberger77999532016-09-29 22:20:19 +0200649
Eric Biggers50d9fad2019-12-09 13:27:21 -0800650 if (IS_ENCRYPTED(inode)) {
Richard Weinberger77999532016-09-29 22:20:19 +0200651 err = ubifs_decrypt(inode, dn, &dlen, page_block);
652 if (err)
653 goto out_err;
654 }
655
Sheng Yong235c3622015-03-20 10:39:42 +0000656 err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len,
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300657 le16_to_cpu(dn->compr_type));
658 if (err || len != out_len)
659 goto out_err;
660
661 if (len < UBIFS_BLOCK_SIZE)
662 memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
663
664 nn += 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300665 read = (i << UBIFS_BLOCK_SHIFT) + len;
Adrian Hunter5c0013c2008-09-12 10:34:51 +0300666 } else if (key_block(c, &bu->zbranch[nn].key) < page_block) {
667 nn += 1;
668 continue;
669 } else {
670 hole = 1;
671 memset(addr, 0, UBIFS_BLOCK_SIZE);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300672 }
673 if (++i >= UBIFS_BLOCKS_PER_PAGE)
674 break;
675 addr += UBIFS_BLOCK_SIZE;
676 page_block += 1;
677 }
678
679 if (end_index == page->index) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300680 int len = i_size & (PAGE_SIZE - 1);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300681
Adrian Huntered382d52008-09-05 16:17:42 +0300682 if (len && len < read)
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300683 memset(zaddr + len, 0, read - len);
684 }
685
686out_hole:
687 if (hole) {
688 SetPageChecked(page);
689 dbg_gen("hole");
690 }
691
692 SetPageUptodate(page);
693 ClearPageError(page);
694 flush_dcache_page(page);
695 kunmap(page);
696 *n = nn;
697 return 0;
698
699out_err:
700 ClearPageUptodate(page);
701 SetPageError(page);
702 flush_dcache_page(page);
703 kunmap(page);
Sheng Yong235c3622015-03-20 10:39:42 +0000704 ubifs_err(c, "bad data node (block %u, inode %lu)",
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300705 page_block, inode->i_ino);
706 return -EINVAL;
707}
708
709/**
710 * ubifs_do_bulk_read - do bulk-read.
711 * @c: UBIFS file-system description object
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200712 * @bu: bulk-read information
713 * @page1: first page to read
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300714 *
715 * This function returns %1 if the bulk-read is done, otherwise %0 is returned.
716 */
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200717static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu,
718 struct page *page1)
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300719{
720 pgoff_t offset = page1->index, end_index;
721 struct address_space *mapping = page1->mapping;
722 struct inode *inode = mapping->host;
723 struct ubifs_inode *ui = ubifs_inode(inode);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300724 int err, page_idx, page_cnt, ret = 0, n = 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200725 int allocate = bu->buf ? 0 : 1;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300726 loff_t isize;
Hyunchul Lee480a1a62017-06-14 09:31:49 +0900727 gfp_t ra_gfp_mask = readahead_gfp_mask(mapping) & ~__GFP_FS;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300728
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300729 err = ubifs_tnc_get_bu_keys(c, bu);
730 if (err)
731 goto out_warn;
732
733 if (bu->eof) {
734 /* Turn off bulk-read at the end of the file */
735 ui->read_in_a_row = 1;
736 ui->bulk_read = 0;
737 }
738
739 page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT;
740 if (!page_cnt) {
741 /*
742 * This happens when there are multiple blocks per page and the
743 * blocks for the first page we are looking for, are not
744 * together. If all the pages were like this, bulk-read would
745 * reduce performance, so we turn it off for a while.
746 */
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200747 goto out_bu_off;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300748 }
749
750 if (bu->cnt) {
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200751 if (allocate) {
752 /*
753 * Allocate bulk-read buffer depending on how many data
754 * nodes we are going to read.
755 */
756 bu->buf_len = bu->zbranch[bu->cnt - 1].offs +
757 bu->zbranch[bu->cnt - 1].len -
758 bu->zbranch[0].offs;
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200759 ubifs_assert(c, bu->buf_len > 0);
760 ubifs_assert(c, bu->buf_len <= c->leb_size);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200761 bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN);
762 if (!bu->buf)
763 goto out_bu_off;
764 }
765
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300766 err = ubifs_tnc_bulk_read(c, bu);
767 if (err)
768 goto out_warn;
769 }
770
771 err = populate_page(c, page1, bu, &n);
772 if (err)
773 goto out_warn;
774
775 unlock_page(page1);
776 ret = 1;
777
778 isize = i_size_read(inode);
779 if (isize == 0)
780 goto out_free;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300781 end_index = ((isize - 1) >> PAGE_SHIFT);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300782
783 for (page_idx = 1; page_idx < page_cnt; page_idx++) {
784 pgoff_t page_offset = offset + page_idx;
785 struct page *page;
786
787 if (page_offset > end_index)
788 break;
Zhihao Chengf5de5b832020-01-11 17:50:36 +0800789 page = pagecache_get_page(mapping, page_offset,
790 FGP_LOCK|FGP_ACCESSED|FGP_CREAT|FGP_NOWAIT,
791 ra_gfp_mask);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300792 if (!page)
793 break;
794 if (!PageUptodate(page))
795 err = populate_page(c, page, bu, &n);
796 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300797 put_page(page);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300798 if (err)
799 break;
800 }
801
802 ui->last_page_read = offset + page_idx - 1;
803
804out_free:
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200805 if (allocate)
806 kfree(bu->buf);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300807 return ret;
808
809out_warn:
Sheng Yong235c3622015-03-20 10:39:42 +0000810 ubifs_warn(c, "ignoring error %d and skipping bulk-read", err);
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300811 goto out_free;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200812
813out_bu_off:
814 ui->read_in_a_row = ui->bulk_read = 0;
815 goto out_free;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300816}
817
818/**
819 * ubifs_bulk_read - determine whether to bulk-read and, if so, do it.
820 * @page: page from which to start bulk-read.
821 *
822 * Some flash media are capable of reading sequentially at faster rates. UBIFS
823 * bulk-read facility is designed to take advantage of that, by reading in one
824 * go consecutive data nodes that are also located consecutively in the same
825 * LEB. This function returns %1 if a bulk-read is done and %0 otherwise.
826 */
827static int ubifs_bulk_read(struct page *page)
828{
829 struct inode *inode = page->mapping->host;
830 struct ubifs_info *c = inode->i_sb->s_fs_info;
831 struct ubifs_inode *ui = ubifs_inode(inode);
832 pgoff_t index = page->index, last_page_read = ui->last_page_read;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200833 struct bu_info *bu;
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200834 int err = 0, allocated = 0;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300835
836 ui->last_page_read = index;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300837 if (!c->bulk_read)
838 return 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200839
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300840 /*
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200841 * Bulk-read is protected by @ui->ui_mutex, but it is an optimization,
842 * so don't bother if we cannot lock the mutex.
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300843 */
844 if (!mutex_trylock(&ui->ui_mutex))
845 return 0;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200846
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300847 if (index != last_page_read + 1) {
848 /* Turn off bulk-read if we stop reading sequentially */
849 ui->read_in_a_row = 1;
850 if (ui->bulk_read)
851 ui->bulk_read = 0;
852 goto out_unlock;
853 }
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200854
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300855 if (!ui->bulk_read) {
856 ui->read_in_a_row += 1;
857 if (ui->read_in_a_row < 3)
858 goto out_unlock;
859 /* Three reads in a row, so switch on bulk-read */
860 ui->bulk_read = 1;
861 }
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200862
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200863 /*
864 * If possible, try to use pre-allocated bulk-read information, which
865 * is protected by @c->bu_mutex.
866 */
867 if (mutex_trylock(&c->bu_mutex))
868 bu = &c->bu;
869 else {
870 bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN);
871 if (!bu)
872 goto out_unlock;
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200873
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200874 bu->buf = NULL;
875 allocated = 1;
876 }
877
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200878 bu->buf_len = c->max_bu_buf_len;
879 data_key_init(c, &bu->key, inode->i_ino,
880 page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200881 err = ubifs_do_bulk_read(c, bu, page);
Artem Bityutskiy3477d202008-11-19 11:53:15 +0200882
883 if (!allocated)
884 mutex_unlock(&c->bu_mutex);
885 else
886 kfree(bu);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200887
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300888out_unlock:
889 mutex_unlock(&ui->ui_mutex);
Artem Bityutskiy6c0c42c2008-11-18 20:20:05 +0200890 return err;
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300891}
892
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300893static int ubifs_readpage(struct file *file, struct page *page)
894{
Adrian Hunter4793e7c2008-09-02 16:29:46 +0300895 if (ubifs_bulk_read(page))
896 return 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300897 do_readpage(page);
898 unlock_page(page);
899 return 0;
900}
901
902static int do_writepage(struct page *page, int len)
903{
904 int err = 0, i, blen;
905 unsigned int block;
906 void *addr;
907 union ubifs_key key;
908 struct inode *inode = page->mapping->host;
909 struct ubifs_info *c = inode->i_sb->s_fs_info;
910
911#ifdef UBIFS_DEBUG
Daniel Gollea0fd5952014-05-13 22:27:58 +0200912 struct ubifs_inode *ui = ubifs_inode(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300913 spin_lock(&ui->ui_lock);
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200914 ubifs_assert(c, page->index <= ui->synced_i_size >> PAGE_SHIFT);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300915 spin_unlock(&ui->ui_lock);
916#endif
917
918 /* Update radix tree tags */
919 set_page_writeback(page);
920
921 addr = kmap(page);
922 block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
923 i = 0;
924 while (len) {
925 blen = min_t(int, len, UBIFS_BLOCK_SIZE);
926 data_key_init(c, &key, inode->i_ino, block);
927 err = ubifs_jnl_write_data(c, inode, &key, addr, blen);
928 if (err)
929 break;
930 if (++i >= UBIFS_BLOCKS_PER_PAGE)
931 break;
932 block += 1;
933 addr += blen;
934 len -= blen;
935 }
936 if (err) {
937 SetPageError(page);
Sheng Yong235c3622015-03-20 10:39:42 +0000938 ubifs_err(c, "cannot write page %lu of inode %lu, error %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300939 page->index, inode->i_ino, err);
940 ubifs_ro_mode(c, err);
941 }
942
Richard Weinberger6eb61d52018-07-12 13:01:57 +0200943 ubifs_assert(c, PagePrivate(page));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300944 if (PageChecked(page))
945 release_new_page_budget(c);
946 else
947 release_existing_page_budget(c);
948
949 atomic_long_dec(&c->dirty_pg_cnt);
950 ClearPagePrivate(page);
951 ClearPageChecked(page);
952
953 kunmap(page);
954 unlock_page(page);
955 end_page_writeback(page);
956 return err;
957}
958
959/*
960 * When writing-back dirty inodes, VFS first writes-back pages belonging to the
961 * inode, then the inode itself. For UBIFS this may cause a problem. Consider a
962 * situation when a we have an inode with size 0, then a megabyte of data is
963 * appended to the inode, then write-back starts and flushes some amount of the
964 * dirty pages, the journal becomes full, commit happens and finishes, and then
965 * an unclean reboot happens. When the file system is mounted next time, the
966 * inode size would still be 0, but there would be many pages which are beyond
967 * the inode size, they would be indexed and consume flash space. Because the
968 * journal has been committed, the replay would not be able to detect this
969 * situation and correct the inode size. This means UBIFS would have to scan
970 * whole index and correct all inode sizes, which is long an unacceptable.
971 *
972 * To prevent situations like this, UBIFS writes pages back only if they are
Artem Bityutskiy7d4e9cc2009-03-20 19:11:12 +0200973 * within the last synchronized inode size, i.e. the size which has been
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300974 * written to the flash media last time. Otherwise, UBIFS forces inode
975 * write-back, thus making sure the on-flash inode contains current inode size,
976 * and then keeps writing pages back.
977 *
978 * Some locking issues explanation. 'ubifs_writepage()' first is called with
979 * the page locked, and it locks @ui_mutex. However, write-back does take inode
980 * @i_mutex, which means other VFS operations may be run on this inode at the
981 * same time. And the problematic one is truncation to smaller size, from where
Artem Bityutskiyc4361572011-03-25 15:27:40 +0200982 * we have to call 'truncate_setsize()', which first changes @inode->i_size,
983 * then drops the truncated pages. And while dropping the pages, it takes the
984 * page lock. This means that 'do_truncation()' cannot call 'truncate_setsize()'
985 * with @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'.
986 * This means that @inode->i_size is changed while @ui_mutex is unlocked.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300987 *
Christoph Hellwig2c27c652010-06-04 11:30:04 +0200988 * XXX(truncate): with the new truncate sequence this is not true anymore,
989 * and the calls to truncate_setsize can be move around freely. They should
990 * be moved to the very end of the truncate sequence.
npiggin@suse.de15c6fd92010-05-27 01:05:34 +1000991 *
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300992 * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond
993 * inode size. How do we do this if @inode->i_size may became smaller while we
994 * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the
995 * @ui->ui_isize "shadow" field which UBIFS uses instead of @inode->i_size
996 * internally and updates it under @ui_mutex.
997 *
998 * Q: why we do not worry that if we race with truncation, we may end up with a
999 * situation when the inode is truncated while we are in the middle of
1000 * 'do_writepage()', so we do write beyond inode size?
1001 * A: If we are in the middle of 'do_writepage()', truncation would be locked
1002 * on the page lock and it would not write the truncated inode node to the
1003 * journal before we have finished.
1004 */
1005static int ubifs_writepage(struct page *page, struct writeback_control *wbc)
1006{
1007 struct inode *inode = page->mapping->host;
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001008 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001009 struct ubifs_inode *ui = ubifs_inode(inode);
1010 loff_t i_size = i_size_read(inode), synced_i_size;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001011 pgoff_t end_index = i_size >> PAGE_SHIFT;
1012 int err, len = i_size & (PAGE_SIZE - 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001013 void *kaddr;
1014
1015 dbg_gen("ino %lu, pg %lu, pg flags %#lx",
1016 inode->i_ino, page->index, page->flags);
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001017 ubifs_assert(c, PagePrivate(page));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001018
1019 /* Is the page fully outside @i_size? (truncate in progress) */
1020 if (page->index > end_index || (page->index == end_index && !len)) {
1021 err = 0;
1022 goto out_unlock;
1023 }
1024
1025 spin_lock(&ui->ui_lock);
1026 synced_i_size = ui->synced_i_size;
1027 spin_unlock(&ui->ui_lock);
1028
1029 /* Is the page fully inside @i_size? */
1030 if (page->index < end_index) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001031 if (page->index >= synced_i_size >> PAGE_SHIFT) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001032 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001033 if (err)
1034 goto out_unlock;
1035 /*
1036 * The inode has been written, but the write-buffer has
1037 * not been synchronized, so in case of an unclean
1038 * reboot we may end up with some pages beyond inode
1039 * size, but they would be in the journal (because
1040 * commit flushes write buffers) and recovery would deal
1041 * with this.
1042 */
1043 }
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001044 return do_writepage(page, PAGE_SIZE);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001045 }
1046
1047 /*
1048 * The page straddles @i_size. It must be zeroed out on each and every
1049 * writepage invocation because it may be mmapped. "A file is mapped
1050 * in multiples of the page size. For a file that is not a multiple of
1051 * the page size, the remaining memory is zeroed when mapped, and
1052 * writes to that region are not written out to the file."
1053 */
Cong Wanga1c7c132011-11-25 23:14:36 +08001054 kaddr = kmap_atomic(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001055 memset(kaddr + len, 0, PAGE_SIZE - len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001056 flush_dcache_page(page);
Cong Wanga1c7c132011-11-25 23:14:36 +08001057 kunmap_atomic(kaddr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001058
1059 if (i_size > synced_i_size) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001060 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001061 if (err)
1062 goto out_unlock;
1063 }
1064
1065 return do_writepage(page, len);
1066
1067out_unlock:
1068 unlock_page(page);
1069 return err;
1070}
1071
1072/**
1073 * do_attr_changes - change inode attributes.
1074 * @inode: inode to change attributes for
1075 * @attr: describes attributes to change
1076 */
1077static void do_attr_changes(struct inode *inode, const struct iattr *attr)
1078{
1079 if (attr->ia_valid & ATTR_UID)
1080 inode->i_uid = attr->ia_uid;
1081 if (attr->ia_valid & ATTR_GID)
1082 inode->i_gid = attr->ia_gid;
Amir Goldsteineb31e2f2019-11-24 21:31:45 +02001083 if (attr->ia_valid & ATTR_ATIME)
1084 inode->i_atime = attr->ia_atime;
1085 if (attr->ia_valid & ATTR_MTIME)
1086 inode->i_mtime = attr->ia_mtime;
1087 if (attr->ia_valid & ATTR_CTIME)
1088 inode->i_ctime = attr->ia_ctime;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001089 if (attr->ia_valid & ATTR_MODE) {
1090 umode_t mode = attr->ia_mode;
1091
1092 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
1093 mode &= ~S_ISGID;
1094 inode->i_mode = mode;
1095 }
1096}
1097
1098/**
1099 * do_truncation - truncate an inode.
1100 * @c: UBIFS file-system description object
1101 * @inode: inode to truncate
1102 * @attr: inode attribute changes description
1103 *
1104 * This function implements VFS '->setattr()' call when the inode is truncated
1105 * to a smaller size. Returns zero in case of success and a negative error code
1106 * in case of failure.
1107 */
1108static int do_truncation(struct ubifs_info *c, struct inode *inode,
1109 const struct iattr *attr)
1110{
1111 int err;
1112 struct ubifs_budget_req req;
1113 loff_t old_size = inode->i_size, new_size = attr->ia_size;
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001114 int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001115 struct ubifs_inode *ui = ubifs_inode(inode);
1116
1117 dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size);
1118 memset(&req, 0, sizeof(struct ubifs_budget_req));
1119
1120 /*
1121 * If this is truncation to a smaller size, and we do not truncate on a
1122 * block boundary, budget for changing one data block, because the last
1123 * block will be re-written.
1124 */
1125 if (new_size & (UBIFS_BLOCK_SIZE - 1))
1126 req.dirtied_page = 1;
1127
1128 req.dirtied_ino = 1;
1129 /* A funny way to budget for truncation node */
1130 req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ;
1131 err = ubifs_budget_space(c, &req);
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001132 if (err) {
1133 /*
1134 * Treat truncations to zero as deletion and always allow them,
1135 * just like we do for '->unlink()'.
1136 */
1137 if (new_size || err != -ENOSPC)
1138 return err;
1139 budgeted = 0;
1140 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001141
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001142 truncate_setsize(inode, new_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001143
1144 if (offset) {
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001145 pgoff_t index = new_size >> PAGE_SHIFT;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001146 struct page *page;
1147
1148 page = find_lock_page(inode->i_mapping, index);
1149 if (page) {
1150 if (PageDirty(page)) {
1151 /*
1152 * 'ubifs_jnl_truncate()' will try to truncate
1153 * the last data node, but it contains
1154 * out-of-date data because the page is dirty.
1155 * Write the page now, so that
1156 * 'ubifs_jnl_truncate()' will see an already
1157 * truncated (and up to date) data node.
1158 */
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001159 ubifs_assert(c, PagePrivate(page));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001160
1161 clear_page_dirty_for_io(page);
1162 if (UBIFS_BLOCKS_PER_PAGE_SHIFT)
1163 offset = new_size &
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001164 (PAGE_SIZE - 1);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001165 err = do_writepage(page, offset);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001166 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001167 if (err)
1168 goto out_budg;
1169 /*
1170 * We could now tell 'ubifs_jnl_truncate()' not
1171 * to read the last block.
1172 */
1173 } else {
1174 /*
1175 * We could 'kmap()' the page and pass the data
1176 * to 'ubifs_jnl_truncate()' to save it from
1177 * having to read it.
1178 */
1179 unlock_page(page);
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001180 put_page(page);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001181 }
1182 }
1183 }
1184
1185 mutex_lock(&ui->ui_mutex);
1186 ui->ui_size = inode->i_size;
1187 /* Truncation changes inode [mc]time */
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001188 inode->i_mtime = inode->i_ctime = current_time(inode);
Artem Bityutskiy873a64c2009-09-01 17:06:43 +03001189 /* Other attributes may be changed at the same time as well */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001190 do_attr_changes(inode, attr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001191 err = ubifs_jnl_truncate(c, inode, old_size, new_size);
1192 mutex_unlock(&ui->ui_mutex);
Artem Bityutskiy873a64c2009-09-01 17:06:43 +03001193
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001194out_budg:
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001195 if (budgeted)
1196 ubifs_release_budget(c, &req);
1197 else {
Artem Bityutskiyb1375452011-03-29 18:04:05 +03001198 c->bi.nospace = c->bi.nospace_rp = 0;
Artem Bityutskiy04da11b2008-08-20 17:16:34 +03001199 smp_wmb();
1200 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001201 return err;
1202}
1203
1204/**
1205 * do_setattr - change inode attributes.
1206 * @c: UBIFS file-system description object
1207 * @inode: inode to change attributes for
1208 * @attr: inode attribute changes description
1209 *
1210 * This function implements VFS '->setattr()' call for all cases except
1211 * truncations to smaller size. Returns zero in case of success and a negative
1212 * error code in case of failure.
1213 */
1214static int do_setattr(struct ubifs_info *c, struct inode *inode,
1215 const struct iattr *attr)
1216{
1217 int err, release;
1218 loff_t new_size = attr->ia_size;
1219 struct ubifs_inode *ui = ubifs_inode(inode);
1220 struct ubifs_budget_req req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001221 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001222
1223 err = ubifs_budget_space(c, &req);
1224 if (err)
1225 return err;
1226
1227 if (attr->ia_valid & ATTR_SIZE) {
1228 dbg_gen("size %lld -> %lld", inode->i_size, new_size);
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001229 truncate_setsize(inode, new_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001230 }
1231
1232 mutex_lock(&ui->ui_mutex);
1233 if (attr->ia_valid & ATTR_SIZE) {
1234 /* Truncation changes inode [mc]time */
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001235 inode->i_mtime = inode->i_ctime = current_time(inode);
Christoph Hellwig2c27c652010-06-04 11:30:04 +02001236 /* 'truncate_setsize()' changed @i_size, update @ui_size */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001237 ui->ui_size = inode->i_size;
1238 }
1239
1240 do_attr_changes(inode, attr);
1241
1242 release = ui->dirty;
1243 if (attr->ia_valid & ATTR_SIZE)
1244 /*
1245 * Inode length changed, so we have to make sure
1246 * @I_DIRTY_DATASYNC is set.
1247 */
Christoph Hellwigf3556252018-02-21 07:54:48 -08001248 __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001249 else
1250 mark_inode_dirty_sync(inode);
1251 mutex_unlock(&ui->ui_mutex);
1252
1253 if (release)
1254 ubifs_release_budget(c, &req);
1255 if (IS_SYNC(inode))
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001256 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001257 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001258}
1259
1260int ubifs_setattr(struct dentry *dentry, struct iattr *attr)
1261{
1262 int err;
David Howells2b0143b2015-03-17 22:25:59 +00001263 struct inode *inode = d_inode(dentry);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001264 struct ubifs_info *c = inode->i_sb->s_fs_info;
1265
Artem Bityutskiy7d32c2b2008-07-18 18:54:29 +03001266 dbg_gen("ino %lu, mode %#x, ia_valid %#x",
1267 inode->i_ino, inode->i_mode, attr->ia_valid);
Jan Kara31051c82016-05-26 16:55:18 +02001268 err = setattr_prepare(dentry, attr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001269 if (err)
1270 return err;
1271
Artem Bityutskiyd808efb2011-05-31 18:14:38 +03001272 err = dbg_check_synced_i_size(c, inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001273 if (err)
1274 return err;
1275
Eric Biggers252153b2017-11-29 12:43:17 -08001276 err = fscrypt_prepare_setattr(dentry, attr);
1277 if (err)
1278 return err;
Eric Biggers4afb9992017-06-13 16:47:55 -07001279
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001280 if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size < inode->i_size)
1281 /* Truncation to a smaller size */
1282 err = do_truncation(c, inode, attr);
1283 else
1284 err = do_setattr(c, inode, attr);
1285
1286 return err;
1287}
1288
Lukas Czernerd47992f2013-05-21 23:17:23 -04001289static void ubifs_invalidatepage(struct page *page, unsigned int offset,
1290 unsigned int length)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001291{
1292 struct inode *inode = page->mapping->host;
1293 struct ubifs_info *c = inode->i_sb->s_fs_info;
1294
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001295 ubifs_assert(c, PagePrivate(page));
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +03001296 if (offset || length < PAGE_SIZE)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001297 /* Partial page remains dirty */
1298 return;
1299
1300 if (PageChecked(page))
1301 release_new_page_budget(c);
1302 else
1303 release_existing_page_budget(c);
1304
1305 atomic_long_dec(&c->dirty_pg_cnt);
1306 ClearPagePrivate(page);
1307 ClearPageChecked(page);
1308}
1309
Josef Bacik02c24a82011-07-16 20:44:56 -04001310int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001311{
Christoph Hellwig7ea80852010-05-26 17:53:25 +02001312 struct inode *inode = file->f_mapping->host;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001313 struct ubifs_info *c = inode->i_sb->s_fs_info;
1314 int err;
1315
1316 dbg_gen("syncing inode %lu", inode->i_ino);
1317
Artem Bityutskiy3b2f9a02011-04-21 15:11:33 +03001318 if (c->ro_mount)
1319 /*
1320 * For some really strange reasons VFS does not filter out
1321 * 'fsync()' for R/O mounted file-systems as per 2.6.39.
1322 */
Artem Bityutskiy78530bf2011-04-13 10:31:52 +03001323 return 0;
1324
Jeff Layton3b49c9a2017-07-07 15:20:52 -04001325 err = file_write_and_wait_range(file, start, end);
Josef Bacik02c24a82011-07-16 20:44:56 -04001326 if (err)
1327 return err;
Al Viro59551022016-01-22 15:40:57 -05001328 inode_lock(inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001329
1330 /* Synchronize the inode unless this is a 'datasync()' call. */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001331 if (!datasync || (inode->i_state & I_DIRTY_DATASYNC)) {
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001332 err = inode->i_sb->s_op->write_inode(inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001333 if (err)
Josef Bacik02c24a82011-07-16 20:44:56 -04001334 goto out;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001335 }
1336
1337 /*
1338 * Nodes related to this inode may still sit in a write-buffer. Flush
1339 * them.
1340 */
1341 err = ubifs_sync_wbufs_by_inode(c, inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001342out:
Al Viro59551022016-01-22 15:40:57 -05001343 inode_unlock(inode);
Josef Bacik02c24a82011-07-16 20:44:56 -04001344 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001345}
1346
1347/**
1348 * mctime_update_needed - check if mtime or ctime update is needed.
1349 * @inode: the inode to do the check for
1350 * @now: current time
1351 *
1352 * This helper function checks if the inode mtime/ctime should be updated or
1353 * not. If current values of the time-stamps are within the UBIFS inode time
1354 * granularity, they are not updated. This is an optimization.
1355 */
1356static inline int mctime_update_needed(const struct inode *inode,
Arnd Bergmann0eca0b82018-07-13 16:31:55 +02001357 const struct timespec64 *now)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001358{
Arnd Bergmann0eca0b82018-07-13 16:31:55 +02001359 if (!timespec64_equal(&inode->i_mtime, now) ||
1360 !timespec64_equal(&inode->i_ctime, now))
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001361 return 1;
1362 return 0;
1363}
1364
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001365/**
1366 * ubifs_update_time - update time of inode.
1367 * @inode: inode to update
1368 *
1369 * This function updates time of the inode.
1370 */
Deepa Dinamani95582b02018-05-08 19:36:02 -07001371int ubifs_update_time(struct inode *inode, struct timespec64 *time,
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001372 int flags)
1373{
1374 struct ubifs_inode *ui = ubifs_inode(inode);
1375 struct ubifs_info *c = inode->i_sb->s_fs_info;
1376 struct ubifs_budget_req req = { .dirtied_ino = 1,
1377 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001378 int err, release;
1379
Sascha Hauere3d73de2019-03-26 08:52:32 +01001380 if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
1381 return generic_update_time(inode, time, flags);
1382
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001383 err = ubifs_budget_space(c, &req);
1384 if (err)
1385 return err;
1386
1387 mutex_lock(&ui->ui_mutex);
1388 if (flags & S_ATIME)
1389 inode->i_atime = *time;
1390 if (flags & S_CTIME)
1391 inode->i_ctime = *time;
1392 if (flags & S_MTIME)
1393 inode->i_mtime = *time;
1394
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001395 release = ui->dirty;
Christoph Hellwigecf84092020-04-09 13:33:05 +02001396 __mark_inode_dirty(inode, I_DIRTY_SYNC);
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001397 mutex_unlock(&ui->ui_mutex);
1398 if (release)
1399 ubifs_release_budget(c, &req);
1400 return 0;
1401}
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001402
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001403/**
Julia Lawallec037df2016-10-01 22:53:11 +02001404 * update_mctime - update mtime and ctime of an inode.
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001405 * @inode: inode to update
1406 *
1407 * This function updates mtime and ctime of the inode if it is not equivalent to
1408 * current time. Returns zero in case of success and a negative error code in
1409 * case of failure.
1410 */
Al Virof5674c32014-04-03 14:00:23 -04001411static int update_mctime(struct inode *inode)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001412{
Arnd Bergmann0eca0b82018-07-13 16:31:55 +02001413 struct timespec64 now = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001414 struct ubifs_inode *ui = ubifs_inode(inode);
Al Virof5674c32014-04-03 14:00:23 -04001415 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001416
1417 if (mctime_update_needed(inode, &now)) {
1418 int err, release;
1419 struct ubifs_budget_req req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001420 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001421
1422 err = ubifs_budget_space(c, &req);
1423 if (err)
1424 return err;
1425
1426 mutex_lock(&ui->ui_mutex);
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001427 inode->i_mtime = inode->i_ctime = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001428 release = ui->dirty;
1429 mark_inode_dirty_sync(inode);
1430 mutex_unlock(&ui->ui_mutex);
1431 if (release)
1432 ubifs_release_budget(c, &req);
1433 }
1434
1435 return 0;
1436}
1437
Al Virof5674c32014-04-03 14:00:23 -04001438static ssize_t ubifs_write_iter(struct kiocb *iocb, struct iov_iter *from)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001439{
Al Virof5674c32014-04-03 14:00:23 -04001440 int err = update_mctime(file_inode(iocb->ki_filp));
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001441 if (err)
1442 return err;
1443
Al Virof5674c32014-04-03 14:00:23 -04001444 return generic_file_write_iter(iocb, from);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001445}
1446
1447static int ubifs_set_page_dirty(struct page *page)
1448{
1449 int ret;
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001450 struct inode *inode = page->mapping->host;
1451 struct ubifs_info *c = inode->i_sb->s_fs_info;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001452
1453 ret = __set_page_dirty_nobuffers(page);
1454 /*
1455 * An attempt to dirty a page without budgeting for it - should not
1456 * happen.
1457 */
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001458 ubifs_assert(c, ret == 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001459 return ret;
1460}
1461
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001462#ifdef CONFIG_MIGRATION
1463static int ubifs_migrate_page(struct address_space *mapping,
1464 struct page *newpage, struct page *page, enum migrate_mode mode)
1465{
1466 int rc;
1467
Keith Busch37109692019-07-18 15:58:46 -07001468 rc = migrate_page_move_mapping(mapping, newpage, page, 0);
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001469 if (rc != MIGRATEPAGE_SUCCESS)
1470 return rc;
1471
1472 if (PagePrivate(page)) {
1473 ClearPagePrivate(page);
1474 SetPagePrivate(newpage);
1475 }
1476
Jérôme Glisse2916ecc2017-09-08 16:12:06 -07001477 if (mode != MIGRATE_SYNC_NO_COPY)
1478 migrate_page_copy(newpage, page);
1479 else
1480 migrate_page_states(newpage, page);
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001481 return MIGRATEPAGE_SUCCESS;
1482}
1483#endif
1484
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001485static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags)
1486{
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001487 struct inode *inode = page->mapping->host;
1488 struct ubifs_info *c = inode->i_sb->s_fs_info;
1489
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001490 /*
1491 * An attempt to release a dirty page without budgeting for it - should
1492 * not happen.
1493 */
1494 if (PageWriteback(page))
1495 return 0;
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001496 ubifs_assert(c, PagePrivate(page));
1497 ubifs_assert(c, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001498 ClearPagePrivate(page);
1499 ClearPageChecked(page);
1500 return 1;
1501}
1502
1503/*
Artem Bityutskiyc4361572011-03-25 15:27:40 +02001504 * mmap()d file has taken write protection fault and is being made writable.
1505 * UBIFS must ensure page is budgeted for.
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001506 */
Souptick Joarder31c49ea2018-04-15 01:48:59 +05301507static vm_fault_t ubifs_vm_page_mkwrite(struct vm_fault *vmf)
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001508{
Nick Pigginc2ec1752009-03-31 15:23:21 -07001509 struct page *page = vmf->page;
Dave Jiang11bac802017-02-24 14:56:41 -08001510 struct inode *inode = file_inode(vmf->vma->vm_file);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001511 struct ubifs_info *c = inode->i_sb->s_fs_info;
Arnd Bergmann0eca0b82018-07-13 16:31:55 +02001512 struct timespec64 now = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001513 struct ubifs_budget_req req = { .new_page = 1 };
1514 int err, update_time;
1515
1516 dbg_gen("ino %lu, pg %lu, i_size %lld", inode->i_ino, page->index,
1517 i_size_read(inode));
Richard Weinberger6eb61d52018-07-12 13:01:57 +02001518 ubifs_assert(c, !c->ro_media && !c->ro_mount);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001519
Artem Bityutskiy2680d722010-09-17 16:44:28 +03001520 if (unlikely(c->ro_error))
Nick Pigginc2ec1752009-03-31 15:23:21 -07001521 return VM_FAULT_SIGBUS; /* -EROFS */
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001522
1523 /*
1524 * We have not locked @page so far so we may budget for changing the
1525 * page. Note, we cannot do this after we locked the page, because
1526 * budgeting may cause write-back which would cause deadlock.
1527 *
1528 * At the moment we do not know whether the page is dirty or not, so we
1529 * assume that it is not and budget for a new page. We could look at
1530 * the @PG_private flag and figure this out, but we may race with write
1531 * back and the page state may change by the time we lock it, so this
1532 * would need additional care. We do not bother with this at the
1533 * moment, although it might be good idea to do. Instead, we allocate
1534 * budget for a new page and amend it later on if the page was in fact
1535 * dirty.
1536 *
1537 * The budgeting-related logic of this function is similar to what we
1538 * do in 'ubifs_write_begin()' and 'ubifs_write_end()'. Glance there
1539 * for more comments.
1540 */
1541 update_time = mctime_update_needed(inode, &now);
1542 if (update_time)
1543 /*
1544 * We have to change inode time stamp which requires extra
1545 * budgeting.
1546 */
1547 req.dirtied_ino = 1;
1548
1549 err = ubifs_budget_space(c, &req);
1550 if (unlikely(err)) {
1551 if (err == -ENOSPC)
Sheng Yong235c3622015-03-20 10:39:42 +00001552 ubifs_warn(c, "out of space for mmapped file (inode number %lu)",
Artem Bityutskiy79fda512012-08-27 13:34:09 +03001553 inode->i_ino);
Nick Pigginc2ec1752009-03-31 15:23:21 -07001554 return VM_FAULT_SIGBUS;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001555 }
1556
1557 lock_page(page);
1558 if (unlikely(page->mapping != inode->i_mapping ||
1559 page_offset(page) > i_size_read(inode))) {
1560 /* Page got truncated out from underneath us */
Souptick Joarder31c49ea2018-04-15 01:48:59 +05301561 goto sigbus;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001562 }
1563
1564 if (PagePrivate(page))
1565 release_new_page_budget(c);
1566 else {
1567 if (!PageChecked(page))
1568 ubifs_convert_page_budget(c);
1569 SetPagePrivate(page);
1570 atomic_long_inc(&c->dirty_pg_cnt);
1571 __set_page_dirty_nobuffers(page);
1572 }
1573
1574 if (update_time) {
1575 int release;
1576 struct ubifs_inode *ui = ubifs_inode(inode);
1577
1578 mutex_lock(&ui->ui_mutex);
Deepa Dinamani607a11a2017-05-08 15:59:25 -07001579 inode->i_mtime = inode->i_ctime = current_time(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001580 release = ui->dirty;
1581 mark_inode_dirty_sync(inode);
1582 mutex_unlock(&ui->ui_mutex);
1583 if (release)
1584 ubifs_release_dirty_inode_budget(c, ui);
1585 }
1586
Jan Kara182dcfd2013-02-21 16:42:59 -08001587 wait_for_stable_page(page);
hujianyang691a7c62014-04-30 14:06:06 +08001588 return VM_FAULT_LOCKED;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001589
Souptick Joarder31c49ea2018-04-15 01:48:59 +05301590sigbus:
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001591 unlock_page(page);
1592 ubifs_release_budget(c, &req);
Souptick Joarder31c49ea2018-04-15 01:48:59 +05301593 return VM_FAULT_SIGBUS;
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001594}
1595
Alexey Dobriyanf0f37e2f2009-09-27 22:29:37 +04001596static const struct vm_operations_struct ubifs_file_vm_ops = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001597 .fault = filemap_fault,
Kirill A. Shutemovf1820362014-04-07 15:37:19 -07001598 .map_pages = filemap_map_pages,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001599 .page_mkwrite = ubifs_vm_page_mkwrite,
1600};
1601
1602static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma)
1603{
1604 int err;
1605
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001606 err = generic_file_mmap(file, vma);
1607 if (err)
1608 return err;
1609 vma->vm_ops = &ubifs_file_vm_ops;
Sascha Hauere3d73de2019-03-26 08:52:32 +01001610
1611 if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
1612 file_accessed(file);
1613
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001614 return 0;
1615}
1616
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001617static const char *ubifs_get_link(struct dentry *dentry,
1618 struct inode *inode,
1619 struct delayed_call *done)
1620{
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001621 struct ubifs_inode *ui = ubifs_inode(inode);
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001622
Eric Biggers81dd76b2018-01-11 23:27:00 -05001623 if (!IS_ENCRYPTED(inode))
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001624 return ui->data;
1625
1626 if (!dentry)
1627 return ERR_PTR(-ECHILD);
1628
Eric Biggers81dd76b2018-01-11 23:27:00 -05001629 return fscrypt_get_symlink(inode, ui->data, ui->data_len, done);
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001630}
1631
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001632const struct address_space_operations ubifs_file_address_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001633 .readpage = ubifs_readpage,
1634 .writepage = ubifs_writepage,
1635 .write_begin = ubifs_write_begin,
1636 .write_end = ubifs_write_end,
1637 .invalidatepage = ubifs_invalidatepage,
1638 .set_page_dirty = ubifs_set_page_dirty,
Kirill A. Shutemov4ac1c172016-06-16 23:26:15 +02001639#ifdef CONFIG_MIGRATION
1640 .migratepage = ubifs_migrate_page,
1641#endif
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001642 .releasepage = ubifs_releasepage,
1643};
1644
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001645const struct inode_operations ubifs_file_inode_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001646 .setattr = ubifs_setattr,
1647 .getattr = ubifs_getattr,
Stefan Agner7e5471c2018-07-31 15:13:20 +02001648#ifdef CONFIG_UBIFS_FS_XATTR
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001649 .listxattr = ubifs_listxattr,
Stefan Agner7e5471c2018-07-31 15:13:20 +02001650#endif
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001651 .update_time = ubifs_update_time,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001652};
1653
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001654const struct inode_operations ubifs_symlink_inode_operations = {
Richard Weinbergerca7f85b2016-10-08 13:24:26 +02001655 .get_link = ubifs_get_link,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001656 .setattr = ubifs_setattr,
1657 .getattr = ubifs_getattr,
Stefan Agner7e5471c2018-07-31 15:13:20 +02001658#ifdef CONFIG_UBIFS_FS_XATTR
Subodh Nijsure895d9db2014-10-31 13:50:29 -05001659 .listxattr = ubifs_listxattr,
Stefan Agner7e5471c2018-07-31 15:13:20 +02001660#endif
Dongsheng Yang8c1c5f22015-11-07 12:46:11 +08001661 .update_time = ubifs_update_time,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001662};
1663
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001664const struct file_operations ubifs_file_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001665 .llseek = generic_file_llseek,
Al Viroaad4f8b2014-04-02 14:33:16 -04001666 .read_iter = generic_file_read_iter,
Al Virof5674c32014-04-03 14:00:23 -04001667 .write_iter = ubifs_write_iter,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001668 .mmap = ubifs_file_mmap,
1669 .fsync = ubifs_fsync,
1670 .unlocked_ioctl = ubifs_ioctl,
1671 .splice_read = generic_file_splice_read,
Al Viro8d020762014-04-05 04:27:08 -04001672 .splice_write = iter_file_splice_write,
Eric Biggers7e35c4d2017-11-29 12:43:13 -08001673 .open = fscrypt_file_open,
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001674#ifdef CONFIG_COMPAT
1675 .compat_ioctl = ubifs_compat_ioctl,
1676#endif
1677};