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1e51764a AB |
1 | /* |
2 | * This file is part of UBIFS. | |
3 | * | |
4 | * Copyright (C) 2006-2008 Nokia Corporation. | |
5 | * Copyright (C) 2006, 2007 University of Szeged, Hungary | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License version 2 as published by | |
9 | * the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
14 | * more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License along with | |
17 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
18 | * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | * | |
20 | * Authors: Artem Bityutskiy (Битюцкий Артём) | |
21 | * Adrian Hunter | |
22 | * Zoltan Sogor | |
23 | */ | |
24 | ||
25 | /* | |
26 | * This file implements UBIFS I/O subsystem which provides various I/O-related | |
27 | * helper functions (reading/writing/checking/validating nodes) and implements | |
28 | * write-buffering support. Write buffers help to save space which otherwise | |
29 | * would have been wasted for padding to the nearest minimal I/O unit boundary. | |
30 | * Instead, data first goes to the write-buffer and is flushed when the | |
31 | * buffer is full or when it is not used for some time (by timer). This is | |
6f7ab6d4 | 32 | * similar to the mechanism is used by JFFS2. |
1e51764a AB |
33 | * |
34 | * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by | |
35 | * mutexes defined inside these objects. Since sometimes upper-level code | |
36 | * has to lock the write-buffer (e.g. journal space reservation code), many | |
37 | * functions related to write-buffers have "nolock" suffix which means that the | |
38 | * caller has to lock the write-buffer before calling this function. | |
39 | * | |
40 | * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not | |
41 | * aligned, UBIFS starts the next node from the aligned address, and the padded | |
42 | * bytes may contain any rubbish. In other words, UBIFS does not put padding | |
43 | * bytes in those small gaps. Common headers of nodes store real node lengths, | |
44 | * not aligned lengths. Indexing nodes also store real lengths in branches. | |
45 | * | |
46 | * UBIFS uses padding when it pads to the next min. I/O unit. In this case it | |
47 | * uses padding nodes or padding bytes, if the padding node does not fit. | |
48 | * | |
49 | * All UBIFS nodes are protected by CRC checksums and UBIFS checks all nodes | |
50 | * every time they are read from the flash media. | |
51 | */ | |
52 | ||
53 | #include <linux/crc32.h> | |
5a0e3ad6 | 54 | #include <linux/slab.h> |
1e51764a AB |
55 | #include "ubifs.h" |
56 | ||
ff46d7b3 AH |
57 | /** |
58 | * ubifs_ro_mode - switch UBIFS to read read-only mode. | |
59 | * @c: UBIFS file-system description object | |
60 | * @err: error code which is the reason of switching to R/O mode | |
61 | */ | |
62 | void ubifs_ro_mode(struct ubifs_info *c, int err) | |
63 | { | |
64 | if (!c->ro_media) { | |
65 | c->ro_media = 1; | |
ccb3eba7 | 66 | c->no_chk_data_crc = 0; |
2fde99cb | 67 | c->vfs_sb->s_flags |= MS_RDONLY; |
ff46d7b3 AH |
68 | ubifs_warn("switched to read-only mode, error %d", err); |
69 | dbg_dump_stack(); | |
70 | } | |
71 | } | |
72 | ||
1e51764a AB |
73 | /** |
74 | * ubifs_check_node - check node. | |
75 | * @c: UBIFS file-system description object | |
76 | * @buf: node to check | |
77 | * @lnum: logical eraseblock number | |
78 | * @offs: offset within the logical eraseblock | |
79 | * @quiet: print no messages | |
6f7ab6d4 | 80 | * @must_chk_crc: indicates whether to always check the CRC |
1e51764a AB |
81 | * |
82 | * This function checks node magic number and CRC checksum. This function also | |
83 | * validates node length to prevent UBIFS from becoming crazy when an attacker | |
84 | * feeds it a file-system image with incorrect nodes. For example, too large | |
85 | * node length in the common header could cause UBIFS to read memory outside of | |
86 | * allocated buffer when checking the CRC checksum. | |
87 | * | |
6f7ab6d4 AB |
88 | * This function may skip data nodes CRC checking if @c->no_chk_data_crc is |
89 | * true, which is controlled by corresponding UBIFS mount option. However, if | |
90 | * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is | |
91 | * checked. Similarly, if @c->always_chk_crc is true, @c->no_chk_data_crc is | |
92 | * ignored and CRC is checked. | |
93 | * | |
94 | * This function returns zero in case of success and %-EUCLEAN in case of bad | |
95 | * CRC or magic. | |
1e51764a AB |
96 | */ |
97 | int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, | |
6f7ab6d4 | 98 | int offs, int quiet, int must_chk_crc) |
1e51764a AB |
99 | { |
100 | int err = -EINVAL, type, node_len; | |
101 | uint32_t crc, node_crc, magic; | |
102 | const struct ubifs_ch *ch = buf; | |
103 | ||
104 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); | |
105 | ubifs_assert(!(offs & 7) && offs < c->leb_size); | |
106 | ||
107 | magic = le32_to_cpu(ch->magic); | |
108 | if (magic != UBIFS_NODE_MAGIC) { | |
109 | if (!quiet) | |
110 | ubifs_err("bad magic %#08x, expected %#08x", | |
111 | magic, UBIFS_NODE_MAGIC); | |
112 | err = -EUCLEAN; | |
113 | goto out; | |
114 | } | |
115 | ||
116 | type = ch->node_type; | |
117 | if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) { | |
118 | if (!quiet) | |
119 | ubifs_err("bad node type %d", type); | |
120 | goto out; | |
121 | } | |
122 | ||
123 | node_len = le32_to_cpu(ch->len); | |
124 | if (node_len + offs > c->leb_size) | |
125 | goto out_len; | |
126 | ||
127 | if (c->ranges[type].max_len == 0) { | |
128 | if (node_len != c->ranges[type].len) | |
129 | goto out_len; | |
130 | } else if (node_len < c->ranges[type].min_len || | |
131 | node_len > c->ranges[type].max_len) | |
132 | goto out_len; | |
133 | ||
6f7ab6d4 AB |
134 | if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->always_chk_crc && |
135 | c->no_chk_data_crc) | |
136 | return 0; | |
2953e73f | 137 | |
1e51764a AB |
138 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); |
139 | node_crc = le32_to_cpu(ch->crc); | |
140 | if (crc != node_crc) { | |
141 | if (!quiet) | |
142 | ubifs_err("bad CRC: calculated %#08x, read %#08x", | |
143 | crc, node_crc); | |
144 | err = -EUCLEAN; | |
145 | goto out; | |
146 | } | |
147 | ||
148 | return 0; | |
149 | ||
150 | out_len: | |
151 | if (!quiet) | |
152 | ubifs_err("bad node length %d", node_len); | |
153 | out: | |
154 | if (!quiet) { | |
155 | ubifs_err("bad node at LEB %d:%d", lnum, offs); | |
156 | dbg_dump_node(c, buf); | |
157 | dbg_dump_stack(); | |
158 | } | |
159 | return err; | |
160 | } | |
161 | ||
162 | /** | |
163 | * ubifs_pad - pad flash space. | |
164 | * @c: UBIFS file-system description object | |
165 | * @buf: buffer to put padding to | |
166 | * @pad: how many bytes to pad | |
167 | * | |
168 | * The flash media obliges us to write only in chunks of %c->min_io_size and | |
169 | * when we have to write less data we add padding node to the write-buffer and | |
170 | * pad it to the next minimal I/O unit's boundary. Padding nodes help when the | |
171 | * media is being scanned. If the amount of wasted space is not enough to fit a | |
172 | * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes | |
173 | * pattern (%UBIFS_PADDING_BYTE). | |
174 | * | |
175 | * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is | |
176 | * used. | |
177 | */ | |
178 | void ubifs_pad(const struct ubifs_info *c, void *buf, int pad) | |
179 | { | |
180 | uint32_t crc; | |
181 | ||
182 | ubifs_assert(pad >= 0 && !(pad & 7)); | |
183 | ||
184 | if (pad >= UBIFS_PAD_NODE_SZ) { | |
185 | struct ubifs_ch *ch = buf; | |
186 | struct ubifs_pad_node *pad_node = buf; | |
187 | ||
188 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); | |
189 | ch->node_type = UBIFS_PAD_NODE; | |
190 | ch->group_type = UBIFS_NO_NODE_GROUP; | |
191 | ch->padding[0] = ch->padding[1] = 0; | |
192 | ch->sqnum = 0; | |
193 | ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ); | |
194 | pad -= UBIFS_PAD_NODE_SZ; | |
195 | pad_node->pad_len = cpu_to_le32(pad); | |
196 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8); | |
197 | ch->crc = cpu_to_le32(crc); | |
198 | memset(buf + UBIFS_PAD_NODE_SZ, 0, pad); | |
199 | } else if (pad > 0) | |
200 | /* Too little space, padding node won't fit */ | |
201 | memset(buf, UBIFS_PADDING_BYTE, pad); | |
202 | } | |
203 | ||
204 | /** | |
205 | * next_sqnum - get next sequence number. | |
206 | * @c: UBIFS file-system description object | |
207 | */ | |
208 | static unsigned long long next_sqnum(struct ubifs_info *c) | |
209 | { | |
210 | unsigned long long sqnum; | |
211 | ||
212 | spin_lock(&c->cnt_lock); | |
213 | sqnum = ++c->max_sqnum; | |
214 | spin_unlock(&c->cnt_lock); | |
215 | ||
216 | if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) { | |
217 | if (sqnum >= SQNUM_WATERMARK) { | |
218 | ubifs_err("sequence number overflow %llu, end of life", | |
219 | sqnum); | |
220 | ubifs_ro_mode(c, -EINVAL); | |
221 | } | |
222 | ubifs_warn("running out of sequence numbers, end of life soon"); | |
223 | } | |
224 | ||
225 | return sqnum; | |
226 | } | |
227 | ||
228 | /** | |
229 | * ubifs_prepare_node - prepare node to be written to flash. | |
230 | * @c: UBIFS file-system description object | |
231 | * @node: the node to pad | |
232 | * @len: node length | |
233 | * @pad: if the buffer has to be padded | |
234 | * | |
235 | * This function prepares node at @node to be written to the media - it | |
236 | * calculates node CRC, fills the common header, and adds proper padding up to | |
237 | * the next minimum I/O unit if @pad is not zero. | |
238 | */ | |
239 | void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad) | |
240 | { | |
241 | uint32_t crc; | |
242 | struct ubifs_ch *ch = node; | |
243 | unsigned long long sqnum = next_sqnum(c); | |
244 | ||
245 | ubifs_assert(len >= UBIFS_CH_SZ); | |
246 | ||
247 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); | |
248 | ch->len = cpu_to_le32(len); | |
249 | ch->group_type = UBIFS_NO_NODE_GROUP; | |
250 | ch->sqnum = cpu_to_le64(sqnum); | |
251 | ch->padding[0] = ch->padding[1] = 0; | |
252 | crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); | |
253 | ch->crc = cpu_to_le32(crc); | |
254 | ||
255 | if (pad) { | |
256 | len = ALIGN(len, 8); | |
257 | pad = ALIGN(len, c->min_io_size) - len; | |
258 | ubifs_pad(c, node + len, pad); | |
259 | } | |
260 | } | |
261 | ||
262 | /** | |
263 | * ubifs_prep_grp_node - prepare node of a group to be written to flash. | |
264 | * @c: UBIFS file-system description object | |
265 | * @node: the node to pad | |
266 | * @len: node length | |
267 | * @last: indicates the last node of the group | |
268 | * | |
269 | * This function prepares node at @node to be written to the media - it | |
270 | * calculates node CRC and fills the common header. | |
271 | */ | |
272 | void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last) | |
273 | { | |
274 | uint32_t crc; | |
275 | struct ubifs_ch *ch = node; | |
276 | unsigned long long sqnum = next_sqnum(c); | |
277 | ||
278 | ubifs_assert(len >= UBIFS_CH_SZ); | |
279 | ||
280 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); | |
281 | ch->len = cpu_to_le32(len); | |
282 | if (last) | |
283 | ch->group_type = UBIFS_LAST_OF_NODE_GROUP; | |
284 | else | |
285 | ch->group_type = UBIFS_IN_NODE_GROUP; | |
286 | ch->sqnum = cpu_to_le64(sqnum); | |
287 | ch->padding[0] = ch->padding[1] = 0; | |
288 | crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); | |
289 | ch->crc = cpu_to_le32(crc); | |
290 | } | |
291 | ||
292 | /** | |
293 | * wbuf_timer_callback - write-buffer timer callback function. | |
294 | * @data: timer data (write-buffer descriptor) | |
295 | * | |
296 | * This function is called when the write-buffer timer expires. | |
297 | */ | |
f2c5dbd7 | 298 | static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) |
1e51764a | 299 | { |
f2c5dbd7 | 300 | struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer); |
1e51764a | 301 | |
77a7ae58 | 302 | dbg_io("jhead %s", dbg_jhead(wbuf->jhead)); |
1e51764a AB |
303 | wbuf->need_sync = 1; |
304 | wbuf->c->need_wbuf_sync = 1; | |
305 | ubifs_wake_up_bgt(wbuf->c); | |
f2c5dbd7 | 306 | return HRTIMER_NORESTART; |
1e51764a AB |
307 | } |
308 | ||
309 | /** | |
310 | * new_wbuf_timer - start new write-buffer timer. | |
311 | * @wbuf: write-buffer descriptor | |
312 | */ | |
313 | static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) | |
314 | { | |
f2c5dbd7 | 315 | ubifs_assert(!hrtimer_active(&wbuf->timer)); |
1e51764a | 316 | |
0b335b9d | 317 | if (wbuf->no_timer) |
1e51764a | 318 | return; |
77a7ae58 AB |
319 | dbg_io("set timer for jhead %s, %llu-%llu millisecs", |
320 | dbg_jhead(wbuf->jhead), | |
44737589 AH |
321 | div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC), |
322 | div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta, | |
323 | USEC_PER_SEC)); | |
f2c5dbd7 AB |
324 | hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, |
325 | HRTIMER_MODE_REL); | |
1e51764a AB |
326 | } |
327 | ||
328 | /** | |
329 | * cancel_wbuf_timer - cancel write-buffer timer. | |
330 | * @wbuf: write-buffer descriptor | |
331 | */ | |
332 | static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) | |
333 | { | |
0b335b9d AB |
334 | if (wbuf->no_timer) |
335 | return; | |
1e51764a | 336 | wbuf->need_sync = 0; |
f2c5dbd7 | 337 | hrtimer_cancel(&wbuf->timer); |
1e51764a AB |
338 | } |
339 | ||
340 | /** | |
341 | * ubifs_wbuf_sync_nolock - synchronize write-buffer. | |
342 | * @wbuf: write-buffer to synchronize | |
343 | * | |
344 | * This function synchronizes write-buffer @buf and returns zero in case of | |
345 | * success or a negative error code in case of failure. | |
346 | */ | |
347 | int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) | |
348 | { | |
349 | struct ubifs_info *c = wbuf->c; | |
350 | int err, dirt; | |
351 | ||
352 | cancel_wbuf_timer_nolock(wbuf); | |
353 | if (!wbuf->used || wbuf->lnum == -1) | |
354 | /* Write-buffer is empty or not seeked */ | |
355 | return 0; | |
356 | ||
77a7ae58 AB |
357 | dbg_io("LEB %d:%d, %d bytes, jhead %s", |
358 | wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead)); | |
1e51764a AB |
359 | ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY)); |
360 | ubifs_assert(!(wbuf->avail & 7)); | |
361 | ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size); | |
362 | ||
363 | if (c->ro_media) | |
364 | return -EROFS; | |
365 | ||
366 | ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail); | |
367 | err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, | |
368 | c->min_io_size, wbuf->dtype); | |
369 | if (err) { | |
370 | ubifs_err("cannot write %d bytes to LEB %d:%d", | |
371 | c->min_io_size, wbuf->lnum, wbuf->offs); | |
372 | dbg_dump_stack(); | |
373 | return err; | |
374 | } | |
375 | ||
376 | dirt = wbuf->avail; | |
377 | ||
378 | spin_lock(&wbuf->lock); | |
379 | wbuf->offs += c->min_io_size; | |
380 | wbuf->avail = c->min_io_size; | |
381 | wbuf->used = 0; | |
382 | wbuf->next_ino = 0; | |
383 | spin_unlock(&wbuf->lock); | |
384 | ||
385 | if (wbuf->sync_callback) | |
386 | err = wbuf->sync_callback(c, wbuf->lnum, | |
387 | c->leb_size - wbuf->offs, dirt); | |
388 | return err; | |
389 | } | |
390 | ||
391 | /** | |
392 | * ubifs_wbuf_seek_nolock - seek write-buffer. | |
393 | * @wbuf: write-buffer | |
394 | * @lnum: logical eraseblock number to seek to | |
395 | * @offs: logical eraseblock offset to seek to | |
396 | * @dtype: data type | |
397 | * | |
cb54ef8b | 398 | * This function targets the write-buffer to logical eraseblock @lnum:@offs. |
1e51764a AB |
399 | * The write-buffer is synchronized if it is not empty. Returns zero in case of |
400 | * success and a negative error code in case of failure. | |
401 | */ | |
402 | int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs, | |
403 | int dtype) | |
404 | { | |
405 | const struct ubifs_info *c = wbuf->c; | |
406 | ||
77a7ae58 | 407 | dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead)); |
1e51764a AB |
408 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt); |
409 | ubifs_assert(offs >= 0 && offs <= c->leb_size); | |
410 | ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7)); | |
411 | ubifs_assert(lnum != wbuf->lnum); | |
412 | ||
413 | if (wbuf->used > 0) { | |
414 | int err = ubifs_wbuf_sync_nolock(wbuf); | |
415 | ||
416 | if (err) | |
417 | return err; | |
418 | } | |
419 | ||
420 | spin_lock(&wbuf->lock); | |
421 | wbuf->lnum = lnum; | |
422 | wbuf->offs = offs; | |
423 | wbuf->avail = c->min_io_size; | |
424 | wbuf->used = 0; | |
425 | spin_unlock(&wbuf->lock); | |
426 | wbuf->dtype = dtype; | |
427 | ||
428 | return 0; | |
429 | } | |
430 | ||
431 | /** | |
432 | * ubifs_bg_wbufs_sync - synchronize write-buffers. | |
433 | * @c: UBIFS file-system description object | |
434 | * | |
435 | * This function is called by background thread to synchronize write-buffers. | |
436 | * Returns zero in case of success and a negative error code in case of | |
437 | * failure. | |
438 | */ | |
439 | int ubifs_bg_wbufs_sync(struct ubifs_info *c) | |
440 | { | |
441 | int err, i; | |
442 | ||
443 | if (!c->need_wbuf_sync) | |
444 | return 0; | |
445 | c->need_wbuf_sync = 0; | |
446 | ||
447 | if (c->ro_media) { | |
448 | err = -EROFS; | |
449 | goto out_timers; | |
450 | } | |
451 | ||
452 | dbg_io("synchronize"); | |
453 | for (i = 0; i < c->jhead_cnt; i++) { | |
454 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; | |
455 | ||
456 | cond_resched(); | |
457 | ||
458 | /* | |
459 | * If the mutex is locked then wbuf is being changed, so | |
460 | * synchronization is not necessary. | |
461 | */ | |
462 | if (mutex_is_locked(&wbuf->io_mutex)) | |
463 | continue; | |
464 | ||
465 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); | |
466 | if (!wbuf->need_sync) { | |
467 | mutex_unlock(&wbuf->io_mutex); | |
468 | continue; | |
469 | } | |
470 | ||
471 | err = ubifs_wbuf_sync_nolock(wbuf); | |
472 | mutex_unlock(&wbuf->io_mutex); | |
473 | if (err) { | |
474 | ubifs_err("cannot sync write-buffer, error %d", err); | |
475 | ubifs_ro_mode(c, err); | |
476 | goto out_timers; | |
477 | } | |
478 | } | |
479 | ||
480 | return 0; | |
481 | ||
482 | out_timers: | |
483 | /* Cancel all timers to prevent repeated errors */ | |
484 | for (i = 0; i < c->jhead_cnt; i++) { | |
485 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; | |
486 | ||
487 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); | |
488 | cancel_wbuf_timer_nolock(wbuf); | |
489 | mutex_unlock(&wbuf->io_mutex); | |
490 | } | |
491 | return err; | |
492 | } | |
493 | ||
494 | /** | |
495 | * ubifs_wbuf_write_nolock - write data to flash via write-buffer. | |
496 | * @wbuf: write-buffer | |
497 | * @buf: node to write | |
498 | * @len: node length | |
499 | * | |
500 | * This function writes data to flash via write-buffer @wbuf. This means that | |
501 | * the last piece of the node won't reach the flash media immediately if it | |
502 | * does not take whole minimal I/O unit. Instead, the node will sit in RAM | |
503 | * until the write-buffer is synchronized (e.g., by timer). | |
504 | * | |
505 | * This function returns zero in case of success and a negative error code in | |
506 | * case of failure. If the node cannot be written because there is no more | |
507 | * space in this logical eraseblock, %-ENOSPC is returned. | |
508 | */ | |
509 | int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) | |
510 | { | |
511 | struct ubifs_info *c = wbuf->c; | |
512 | int err, written, n, aligned_len = ALIGN(len, 8), offs; | |
513 | ||
77a7ae58 AB |
514 | dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len, |
515 | dbg_ntype(((struct ubifs_ch *)buf)->node_type), | |
516 | dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used); | |
1e51764a AB |
517 | ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); |
518 | ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); | |
519 | ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size); | |
520 | ubifs_assert(wbuf->avail > 0 && wbuf->avail <= c->min_io_size); | |
521 | ubifs_assert(mutex_is_locked(&wbuf->io_mutex)); | |
522 | ||
523 | if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { | |
524 | err = -ENOSPC; | |
525 | goto out; | |
526 | } | |
527 | ||
528 | cancel_wbuf_timer_nolock(wbuf); | |
529 | ||
530 | if (c->ro_media) | |
531 | return -EROFS; | |
532 | ||
533 | if (aligned_len <= wbuf->avail) { | |
534 | /* | |
535 | * The node is not very large and fits entirely within | |
536 | * write-buffer. | |
537 | */ | |
538 | memcpy(wbuf->buf + wbuf->used, buf, len); | |
539 | ||
540 | if (aligned_len == wbuf->avail) { | |
77a7ae58 AB |
541 | dbg_io("flush jhead %s wbuf to LEB %d:%d", |
542 | dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); | |
1e51764a AB |
543 | err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, |
544 | wbuf->offs, c->min_io_size, | |
545 | wbuf->dtype); | |
546 | if (err) | |
547 | goto out; | |
548 | ||
549 | spin_lock(&wbuf->lock); | |
550 | wbuf->offs += c->min_io_size; | |
551 | wbuf->avail = c->min_io_size; | |
552 | wbuf->used = 0; | |
553 | wbuf->next_ino = 0; | |
554 | spin_unlock(&wbuf->lock); | |
555 | } else { | |
556 | spin_lock(&wbuf->lock); | |
557 | wbuf->avail -= aligned_len; | |
558 | wbuf->used += aligned_len; | |
559 | spin_unlock(&wbuf->lock); | |
560 | } | |
561 | ||
562 | goto exit; | |
563 | } | |
564 | ||
565 | /* | |
566 | * The node is large enough and does not fit entirely within current | |
567 | * minimal I/O unit. We have to fill and flush write-buffer and switch | |
568 | * to the next min. I/O unit. | |
569 | */ | |
77a7ae58 AB |
570 | dbg_io("flush jhead %s wbuf to LEB %d:%d", |
571 | dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); | |
1e51764a AB |
572 | memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); |
573 | err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs, | |
574 | c->min_io_size, wbuf->dtype); | |
575 | if (err) | |
576 | goto out; | |
577 | ||
578 | offs = wbuf->offs + c->min_io_size; | |
579 | len -= wbuf->avail; | |
580 | aligned_len -= wbuf->avail; | |
581 | written = wbuf->avail; | |
582 | ||
583 | /* | |
584 | * The remaining data may take more whole min. I/O units, so write the | |
585 | * remains multiple to min. I/O unit size directly to the flash media. | |
586 | * We align node length to 8-byte boundary because we anyway flash wbuf | |
587 | * if the remaining space is less than 8 bytes. | |
588 | */ | |
589 | n = aligned_len >> c->min_io_shift; | |
590 | if (n) { | |
591 | n <<= c->min_io_shift; | |
592 | dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, offs); | |
593 | err = ubi_leb_write(c->ubi, wbuf->lnum, buf + written, offs, n, | |
594 | wbuf->dtype); | |
595 | if (err) | |
596 | goto out; | |
597 | offs += n; | |
598 | aligned_len -= n; | |
599 | len -= n; | |
600 | written += n; | |
601 | } | |
602 | ||
603 | spin_lock(&wbuf->lock); | |
604 | if (aligned_len) | |
605 | /* | |
606 | * And now we have what's left and what does not take whole | |
607 | * min. I/O unit, so write it to the write-buffer and we are | |
608 | * done. | |
609 | */ | |
610 | memcpy(wbuf->buf, buf + written, len); | |
611 | ||
612 | wbuf->offs = offs; | |
613 | wbuf->used = aligned_len; | |
614 | wbuf->avail = c->min_io_size - aligned_len; | |
615 | wbuf->next_ino = 0; | |
616 | spin_unlock(&wbuf->lock); | |
617 | ||
618 | exit: | |
619 | if (wbuf->sync_callback) { | |
620 | int free = c->leb_size - wbuf->offs - wbuf->used; | |
621 | ||
622 | err = wbuf->sync_callback(c, wbuf->lnum, free, 0); | |
623 | if (err) | |
624 | goto out; | |
625 | } | |
626 | ||
627 | if (wbuf->used) | |
628 | new_wbuf_timer_nolock(wbuf); | |
629 | ||
630 | return 0; | |
631 | ||
632 | out: | |
633 | ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", | |
634 | len, wbuf->lnum, wbuf->offs, err); | |
635 | dbg_dump_node(c, buf); | |
636 | dbg_dump_stack(); | |
637 | dbg_dump_leb(c, wbuf->lnum); | |
638 | return err; | |
639 | } | |
640 | ||
641 | /** | |
642 | * ubifs_write_node - write node to the media. | |
643 | * @c: UBIFS file-system description object | |
644 | * @buf: the node to write | |
645 | * @len: node length | |
646 | * @lnum: logical eraseblock number | |
647 | * @offs: offset within the logical eraseblock | |
648 | * @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) | |
649 | * | |
650 | * This function automatically fills node magic number, assigns sequence | |
651 | * number, and calculates node CRC checksum. The length of the @buf buffer has | |
652 | * to be aligned to the minimal I/O unit size. This function automatically | |
653 | * appends padding node and padding bytes if needed. Returns zero in case of | |
654 | * success and a negative error code in case of failure. | |
655 | */ | |
656 | int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, | |
657 | int offs, int dtype) | |
658 | { | |
659 | int err, buf_len = ALIGN(len, c->min_io_size); | |
660 | ||
661 | dbg_io("LEB %d:%d, %s, length %d (aligned %d)", | |
662 | lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len, | |
663 | buf_len); | |
664 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); | |
665 | ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size); | |
666 | ||
667 | if (c->ro_media) | |
668 | return -EROFS; | |
669 | ||
670 | ubifs_prepare_node(c, buf, len, 1); | |
671 | err = ubi_leb_write(c->ubi, lnum, buf, offs, buf_len, dtype); | |
672 | if (err) { | |
673 | ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", | |
674 | buf_len, lnum, offs, err); | |
675 | dbg_dump_node(c, buf); | |
676 | dbg_dump_stack(); | |
677 | } | |
678 | ||
679 | return err; | |
680 | } | |
681 | ||
682 | /** | |
683 | * ubifs_read_node_wbuf - read node from the media or write-buffer. | |
684 | * @wbuf: wbuf to check for un-written data | |
685 | * @buf: buffer to read to | |
686 | * @type: node type | |
687 | * @len: node length | |
688 | * @lnum: logical eraseblock number | |
689 | * @offs: offset within the logical eraseblock | |
690 | * | |
691 | * This function reads a node of known type and length, checks it and stores | |
692 | * in @buf. If the node partially or fully sits in the write-buffer, this | |
693 | * function takes data from the buffer, otherwise it reads the flash media. | |
694 | * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative | |
695 | * error code in case of failure. | |
696 | */ | |
697 | int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, | |
698 | int lnum, int offs) | |
699 | { | |
700 | const struct ubifs_info *c = wbuf->c; | |
701 | int err, rlen, overlap; | |
702 | struct ubifs_ch *ch = buf; | |
703 | ||
77a7ae58 AB |
704 | dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs, |
705 | dbg_ntype(type), len, dbg_jhead(wbuf->jhead)); | |
1e51764a AB |
706 | ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
707 | ubifs_assert(!(offs & 7) && offs < c->leb_size); | |
708 | ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); | |
709 | ||
710 | spin_lock(&wbuf->lock); | |
711 | overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); | |
712 | if (!overlap) { | |
713 | /* We may safely unlock the write-buffer and read the data */ | |
714 | spin_unlock(&wbuf->lock); | |
715 | return ubifs_read_node(c, buf, type, len, lnum, offs); | |
716 | } | |
717 | ||
718 | /* Don't read under wbuf */ | |
719 | rlen = wbuf->offs - offs; | |
720 | if (rlen < 0) | |
721 | rlen = 0; | |
722 | ||
723 | /* Copy the rest from the write-buffer */ | |
724 | memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); | |
725 | spin_unlock(&wbuf->lock); | |
726 | ||
727 | if (rlen > 0) { | |
728 | /* Read everything that goes before write-buffer */ | |
729 | err = ubi_read(c->ubi, lnum, buf, offs, rlen); | |
730 | if (err && err != -EBADMSG) { | |
731 | ubifs_err("failed to read node %d from LEB %d:%d, " | |
732 | "error %d", type, lnum, offs, err); | |
733 | dbg_dump_stack(); | |
734 | return err; | |
735 | } | |
736 | } | |
737 | ||
738 | if (type != ch->node_type) { | |
739 | ubifs_err("bad node type (%d but expected %d)", | |
740 | ch->node_type, type); | |
741 | goto out; | |
742 | } | |
743 | ||
2953e73f | 744 | err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
1e51764a AB |
745 | if (err) { |
746 | ubifs_err("expected node type %d", type); | |
747 | return err; | |
748 | } | |
749 | ||
750 | rlen = le32_to_cpu(ch->len); | |
751 | if (rlen != len) { | |
752 | ubifs_err("bad node length %d, expected %d", rlen, len); | |
753 | goto out; | |
754 | } | |
755 | ||
756 | return 0; | |
757 | ||
758 | out: | |
759 | ubifs_err("bad node at LEB %d:%d", lnum, offs); | |
760 | dbg_dump_node(c, buf); | |
761 | dbg_dump_stack(); | |
762 | return -EINVAL; | |
763 | } | |
764 | ||
765 | /** | |
766 | * ubifs_read_node - read node. | |
767 | * @c: UBIFS file-system description object | |
768 | * @buf: buffer to read to | |
769 | * @type: node type | |
770 | * @len: node length (not aligned) | |
771 | * @lnum: logical eraseblock number | |
772 | * @offs: offset within the logical eraseblock | |
773 | * | |
774 | * This function reads a node of known type and and length, checks it and | |
775 | * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched | |
776 | * and a negative error code in case of failure. | |
777 | */ | |
778 | int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, | |
779 | int lnum, int offs) | |
780 | { | |
781 | int err, l; | |
782 | struct ubifs_ch *ch = buf; | |
783 | ||
784 | dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); | |
785 | ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); | |
786 | ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size); | |
787 | ubifs_assert(!(offs & 7) && offs < c->leb_size); | |
788 | ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); | |
789 | ||
790 | err = ubi_read(c->ubi, lnum, buf, offs, len); | |
791 | if (err && err != -EBADMSG) { | |
792 | ubifs_err("cannot read node %d from LEB %d:%d, error %d", | |
793 | type, lnum, offs, err); | |
794 | return err; | |
795 | } | |
796 | ||
797 | if (type != ch->node_type) { | |
798 | ubifs_err("bad node type (%d but expected %d)", | |
799 | ch->node_type, type); | |
800 | goto out; | |
801 | } | |
802 | ||
2953e73f | 803 | err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
1e51764a AB |
804 | if (err) { |
805 | ubifs_err("expected node type %d", type); | |
806 | return err; | |
807 | } | |
808 | ||
809 | l = le32_to_cpu(ch->len); | |
810 | if (l != len) { | |
811 | ubifs_err("bad node length %d, expected %d", l, len); | |
812 | goto out; | |
813 | } | |
814 | ||
815 | return 0; | |
816 | ||
817 | out: | |
818 | ubifs_err("bad node at LEB %d:%d", lnum, offs); | |
819 | dbg_dump_node(c, buf); | |
820 | dbg_dump_stack(); | |
821 | return -EINVAL; | |
822 | } | |
823 | ||
824 | /** | |
825 | * ubifs_wbuf_init - initialize write-buffer. | |
826 | * @c: UBIFS file-system description object | |
827 | * @wbuf: write-buffer to initialize | |
828 | * | |
cb54ef8b | 829 | * This function initializes write-buffer. Returns zero in case of success |
1e51764a AB |
830 | * %-ENOMEM in case of failure. |
831 | */ | |
832 | int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) | |
833 | { | |
834 | size_t size; | |
835 | ||
836 | wbuf->buf = kmalloc(c->min_io_size, GFP_KERNEL); | |
837 | if (!wbuf->buf) | |
838 | return -ENOMEM; | |
839 | ||
840 | size = (c->min_io_size / UBIFS_CH_SZ + 1) * sizeof(ino_t); | |
841 | wbuf->inodes = kmalloc(size, GFP_KERNEL); | |
842 | if (!wbuf->inodes) { | |
843 | kfree(wbuf->buf); | |
844 | wbuf->buf = NULL; | |
845 | return -ENOMEM; | |
846 | } | |
847 | ||
848 | wbuf->used = 0; | |
849 | wbuf->lnum = wbuf->offs = -1; | |
850 | wbuf->avail = c->min_io_size; | |
851 | wbuf->dtype = UBI_UNKNOWN; | |
852 | wbuf->sync_callback = NULL; | |
853 | mutex_init(&wbuf->io_mutex); | |
854 | spin_lock_init(&wbuf->lock); | |
1e51764a | 855 | wbuf->c = c; |
1e51764a AB |
856 | wbuf->next_ino = 0; |
857 | ||
f2c5dbd7 AB |
858 | hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
859 | wbuf->timer.function = wbuf_timer_callback_nolock; | |
2a35a3a8 AB |
860 | wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); |
861 | wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; | |
862 | wbuf->delta *= 1000000000ULL; | |
863 | ubifs_assert(wbuf->delta <= ULONG_MAX); | |
1e51764a AB |
864 | return 0; |
865 | } | |
866 | ||
867 | /** | |
868 | * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array. | |
cb54ef8b | 869 | * @wbuf: the write-buffer where to add |
1e51764a AB |
870 | * @inum: the inode number |
871 | * | |
872 | * This function adds an inode number to the inode array of the write-buffer. | |
873 | */ | |
874 | void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum) | |
875 | { | |
876 | if (!wbuf->buf) | |
877 | /* NOR flash or something similar */ | |
878 | return; | |
879 | ||
880 | spin_lock(&wbuf->lock); | |
881 | if (wbuf->used) | |
882 | wbuf->inodes[wbuf->next_ino++] = inum; | |
883 | spin_unlock(&wbuf->lock); | |
884 | } | |
885 | ||
886 | /** | |
887 | * wbuf_has_ino - returns if the wbuf contains data from the inode. | |
888 | * @wbuf: the write-buffer | |
889 | * @inum: the inode number | |
890 | * | |
891 | * This function returns with %1 if the write-buffer contains some data from the | |
892 | * given inode otherwise it returns with %0. | |
893 | */ | |
894 | static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum) | |
895 | { | |
896 | int i, ret = 0; | |
897 | ||
898 | spin_lock(&wbuf->lock); | |
899 | for (i = 0; i < wbuf->next_ino; i++) | |
900 | if (inum == wbuf->inodes[i]) { | |
901 | ret = 1; | |
902 | break; | |
903 | } | |
904 | spin_unlock(&wbuf->lock); | |
905 | ||
906 | return ret; | |
907 | } | |
908 | ||
909 | /** | |
910 | * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode. | |
911 | * @c: UBIFS file-system description object | |
912 | * @inode: inode to synchronize | |
913 | * | |
914 | * This function synchronizes write-buffers which contain nodes belonging to | |
915 | * @inode. Returns zero in case of success and a negative error code in case of | |
916 | * failure. | |
917 | */ | |
918 | int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode) | |
919 | { | |
920 | int i, err = 0; | |
921 | ||
922 | for (i = 0; i < c->jhead_cnt; i++) { | |
923 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; | |
924 | ||
925 | if (i == GCHD) | |
926 | /* | |
927 | * GC head is special, do not look at it. Even if the | |
928 | * head contains something related to this inode, it is | |
929 | * a _copy_ of corresponding on-flash node which sits | |
930 | * somewhere else. | |
931 | */ | |
932 | continue; | |
933 | ||
934 | if (!wbuf_has_ino(wbuf, inode->i_ino)) | |
935 | continue; | |
936 | ||
937 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); | |
938 | if (wbuf_has_ino(wbuf, inode->i_ino)) | |
939 | err = ubifs_wbuf_sync_nolock(wbuf); | |
940 | mutex_unlock(&wbuf->io_mutex); | |
941 | ||
942 | if (err) { | |
943 | ubifs_ro_mode(c, err); | |
944 | return err; | |
945 | } | |
946 | } | |
947 | return 0; | |
948 | } |