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2b27bdcc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1e51764a AB |
2 | /* |
3 | * This file is part of UBIFS. | |
4 | * | |
5 | * Copyright (C) 2006-2008 Nokia Corporation. | |
6 | * Copyright (C) 2006, 2007 University of Szeged, Hungary | |
7 | * | |
1e51764a AB |
8 | * Authors: Artem Bityutskiy (Битюцкий Артём) |
9 | * Adrian Hunter | |
10 | * Zoltan Sogor | |
11 | */ | |
12 | ||
13 | /* | |
14 | * This file implements UBIFS I/O subsystem which provides various I/O-related | |
15 | * helper functions (reading/writing/checking/validating nodes) and implements | |
16 | * write-buffering support. Write buffers help to save space which otherwise | |
17 | * would have been wasted for padding to the nearest minimal I/O unit boundary. | |
18 | * Instead, data first goes to the write-buffer and is flushed when the | |
19 | * buffer is full or when it is not used for some time (by timer). This is | |
6f7ab6d4 | 20 | * similar to the mechanism is used by JFFS2. |
1e51764a | 21 | * |
6c7f74f7 AB |
22 | * UBIFS distinguishes between minimum write size (@c->min_io_size) and maximum |
23 | * write size (@c->max_write_size). The latter is the maximum amount of bytes | |
24 | * the underlying flash is able to program at a time, and writing in | |
25 | * @c->max_write_size units should presumably be faster. Obviously, | |
26 | * @c->min_io_size <= @c->max_write_size. Write-buffers are of | |
27 | * @c->max_write_size bytes in size for maximum performance. However, when a | |
28 | * write-buffer is flushed, only the portion of it (aligned to @c->min_io_size | |
29 | * boundary) which contains data is written, not the whole write-buffer, | |
30 | * because this is more space-efficient. | |
31 | * | |
32 | * This optimization adds few complications to the code. Indeed, on the one | |
33 | * hand, we want to write in optimal @c->max_write_size bytes chunks, which | |
34 | * also means aligning writes at the @c->max_write_size bytes offsets. On the | |
35 | * other hand, we do not want to waste space when synchronizing the write | |
36 | * buffer, so during synchronization we writes in smaller chunks. And this makes | |
37 | * the next write offset to be not aligned to @c->max_write_size bytes. So the | |
38 | * have to make sure that the write-buffer offset (@wbuf->offs) becomes aligned | |
39 | * to @c->max_write_size bytes again. We do this by temporarily shrinking | |
40 | * write-buffer size (@wbuf->size). | |
41 | * | |
1e51764a AB |
42 | * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by |
43 | * mutexes defined inside these objects. Since sometimes upper-level code | |
44 | * has to lock the write-buffer (e.g. journal space reservation code), many | |
45 | * functions related to write-buffers have "nolock" suffix which means that the | |
46 | * caller has to lock the write-buffer before calling this function. | |
47 | * | |
48 | * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not | |
49 | * aligned, UBIFS starts the next node from the aligned address, and the padded | |
50 | * bytes may contain any rubbish. In other words, UBIFS does not put padding | |
51 | * bytes in those small gaps. Common headers of nodes store real node lengths, | |
52 | * not aligned lengths. Indexing nodes also store real lengths in branches. | |
53 | * | |
54 | * UBIFS uses padding when it pads to the next min. I/O unit. In this case it | |
55 | * uses padding nodes or padding bytes, if the padding node does not fit. | |
56 | * | |
6c7f74f7 AB |
57 | * All UBIFS nodes are protected by CRC checksums and UBIFS checks CRC when |
58 | * they are read from the flash media. | |
1e51764a AB |
59 | */ |
60 | ||
61 | #include <linux/crc32.h> | |
5a0e3ad6 | 62 | #include <linux/slab.h> |
1e51764a AB |
63 | #include "ubifs.h" |
64 | ||
ff46d7b3 AH |
65 | /** |
66 | * ubifs_ro_mode - switch UBIFS to read read-only mode. | |
67 | * @c: UBIFS file-system description object | |
68 | * @err: error code which is the reason of switching to R/O mode | |
69 | */ | |
70 | void ubifs_ro_mode(struct ubifs_info *c, int err) | |
71 | { | |
2680d722 AB |
72 | if (!c->ro_error) { |
73 | c->ro_error = 1; | |
ccb3eba7 | 74 | c->no_chk_data_crc = 0; |
1751e8a6 | 75 | c->vfs_sb->s_flags |= SB_RDONLY; |
235c362b | 76 | ubifs_warn(c, "switched to read-only mode, error %d", err); |
d033c98b | 77 | dump_stack(); |
ff46d7b3 AH |
78 | } |
79 | } | |
80 | ||
83cef708 AB |
81 | /* |
82 | * Below are simple wrappers over UBI I/O functions which include some | |
83 | * additional checks and UBIFS debugging stuff. See corresponding UBI function | |
84 | * for more information. | |
85 | */ | |
86 | ||
87 | int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs, | |
88 | int len, int even_ebadmsg) | |
89 | { | |
90 | int err; | |
91 | ||
92 | err = ubi_read(c->ubi, lnum, buf, offs, len); | |
93 | /* | |
94 | * In case of %-EBADMSG print the error message only if the | |
95 | * @even_ebadmsg is true. | |
96 | */ | |
97 | if (err && (err != -EBADMSG || even_ebadmsg)) { | |
235c362b | 98 | ubifs_err(c, "reading %d bytes from LEB %d:%d failed, error %d", |
83cef708 | 99 | len, lnum, offs, err); |
7c46d0ae | 100 | dump_stack(); |
83cef708 AB |
101 | } |
102 | return err; | |
103 | } | |
104 | ||
105 | int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs, | |
b36a261e | 106 | int len) |
83cef708 AB |
107 | { |
108 | int err; | |
109 | ||
6eb61d58 | 110 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
83cef708 AB |
111 | if (c->ro_error) |
112 | return -EROFS; | |
113 | if (!dbg_is_tst_rcvry(c)) | |
b36a261e | 114 | err = ubi_leb_write(c->ubi, lnum, buf, offs, len); |
83cef708 | 115 | else |
b36a261e | 116 | err = dbg_leb_write(c, lnum, buf, offs, len); |
83cef708 | 117 | if (err) { |
235c362b | 118 | ubifs_err(c, "writing %d bytes to LEB %d:%d failed, error %d", |
83cef708 AB |
119 | len, lnum, offs, err); |
120 | ubifs_ro_mode(c, err); | |
7c46d0ae | 121 | dump_stack(); |
83cef708 AB |
122 | } |
123 | return err; | |
124 | } | |
125 | ||
b36a261e | 126 | int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len) |
83cef708 AB |
127 | { |
128 | int err; | |
129 | ||
6eb61d58 | 130 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
83cef708 AB |
131 | if (c->ro_error) |
132 | return -EROFS; | |
133 | if (!dbg_is_tst_rcvry(c)) | |
b36a261e | 134 | err = ubi_leb_change(c->ubi, lnum, buf, len); |
83cef708 | 135 | else |
b36a261e | 136 | err = dbg_leb_change(c, lnum, buf, len); |
83cef708 | 137 | if (err) { |
235c362b | 138 | ubifs_err(c, "changing %d bytes in LEB %d failed, error %d", |
83cef708 AB |
139 | len, lnum, err); |
140 | ubifs_ro_mode(c, err); | |
7c46d0ae | 141 | dump_stack(); |
83cef708 AB |
142 | } |
143 | return err; | |
144 | } | |
145 | ||
146 | int ubifs_leb_unmap(struct ubifs_info *c, int lnum) | |
147 | { | |
148 | int err; | |
149 | ||
6eb61d58 | 150 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
83cef708 AB |
151 | if (c->ro_error) |
152 | return -EROFS; | |
153 | if (!dbg_is_tst_rcvry(c)) | |
154 | err = ubi_leb_unmap(c->ubi, lnum); | |
155 | else | |
f57cb188 | 156 | err = dbg_leb_unmap(c, lnum); |
83cef708 | 157 | if (err) { |
235c362b | 158 | ubifs_err(c, "unmap LEB %d failed, error %d", lnum, err); |
83cef708 | 159 | ubifs_ro_mode(c, err); |
7c46d0ae | 160 | dump_stack(); |
83cef708 AB |
161 | } |
162 | return err; | |
163 | } | |
164 | ||
b36a261e | 165 | int ubifs_leb_map(struct ubifs_info *c, int lnum) |
83cef708 AB |
166 | { |
167 | int err; | |
168 | ||
6eb61d58 | 169 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
83cef708 AB |
170 | if (c->ro_error) |
171 | return -EROFS; | |
172 | if (!dbg_is_tst_rcvry(c)) | |
b36a261e | 173 | err = ubi_leb_map(c->ubi, lnum); |
83cef708 | 174 | else |
b36a261e | 175 | err = dbg_leb_map(c, lnum); |
83cef708 | 176 | if (err) { |
235c362b | 177 | ubifs_err(c, "mapping LEB %d failed, error %d", lnum, err); |
83cef708 | 178 | ubifs_ro_mode(c, err); |
7c46d0ae | 179 | dump_stack(); |
83cef708 AB |
180 | } |
181 | return err; | |
182 | } | |
183 | ||
184 | int ubifs_is_mapped(const struct ubifs_info *c, int lnum) | |
185 | { | |
186 | int err; | |
187 | ||
188 | err = ubi_is_mapped(c->ubi, lnum); | |
189 | if (err < 0) { | |
235c362b | 190 | ubifs_err(c, "ubi_is_mapped failed for LEB %d, error %d", |
83cef708 | 191 | lnum, err); |
7c46d0ae | 192 | dump_stack(); |
83cef708 AB |
193 | } |
194 | return err; | |
195 | } | |
196 | ||
1e51764a AB |
197 | /** |
198 | * ubifs_check_node - check node. | |
199 | * @c: UBIFS file-system description object | |
200 | * @buf: node to check | |
201 | * @lnum: logical eraseblock number | |
202 | * @offs: offset within the logical eraseblock | |
203 | * @quiet: print no messages | |
6f7ab6d4 | 204 | * @must_chk_crc: indicates whether to always check the CRC |
1e51764a AB |
205 | * |
206 | * This function checks node magic number and CRC checksum. This function also | |
207 | * validates node length to prevent UBIFS from becoming crazy when an attacker | |
208 | * feeds it a file-system image with incorrect nodes. For example, too large | |
209 | * node length in the common header could cause UBIFS to read memory outside of | |
210 | * allocated buffer when checking the CRC checksum. | |
211 | * | |
6f7ab6d4 AB |
212 | * This function may skip data nodes CRC checking if @c->no_chk_data_crc is |
213 | * true, which is controlled by corresponding UBIFS mount option. However, if | |
214 | * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is | |
18d1d7fb AB |
215 | * checked. Similarly, if @c->mounting or @c->remounting_rw is true (we are |
216 | * mounting or re-mounting to R/W mode), @c->no_chk_data_crc is ignored and CRC | |
217 | * is checked. This is because during mounting or re-mounting from R/O mode to | |
218 | * R/W mode we may read journal nodes (when replying the journal or doing the | |
219 | * recovery) and the journal nodes may potentially be corrupted, so checking is | |
220 | * required. | |
6f7ab6d4 AB |
221 | * |
222 | * This function returns zero in case of success and %-EUCLEAN in case of bad | |
223 | * CRC or magic. | |
1e51764a AB |
224 | */ |
225 | int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, | |
6f7ab6d4 | 226 | int offs, int quiet, int must_chk_crc) |
1e51764a AB |
227 | { |
228 | int err = -EINVAL, type, node_len; | |
229 | uint32_t crc, node_crc, magic; | |
230 | const struct ubifs_ch *ch = buf; | |
231 | ||
6eb61d58 RW |
232 | ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
233 | ubifs_assert(c, !(offs & 7) && offs < c->leb_size); | |
1e51764a AB |
234 | |
235 | magic = le32_to_cpu(ch->magic); | |
236 | if (magic != UBIFS_NODE_MAGIC) { | |
237 | if (!quiet) | |
235c362b | 238 | ubifs_err(c, "bad magic %#08x, expected %#08x", |
1e51764a AB |
239 | magic, UBIFS_NODE_MAGIC); |
240 | err = -EUCLEAN; | |
241 | goto out; | |
242 | } | |
243 | ||
244 | type = ch->node_type; | |
245 | if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) { | |
246 | if (!quiet) | |
235c362b | 247 | ubifs_err(c, "bad node type %d", type); |
1e51764a AB |
248 | goto out; |
249 | } | |
250 | ||
251 | node_len = le32_to_cpu(ch->len); | |
252 | if (node_len + offs > c->leb_size) | |
253 | goto out_len; | |
254 | ||
255 | if (c->ranges[type].max_len == 0) { | |
256 | if (node_len != c->ranges[type].len) | |
257 | goto out_len; | |
258 | } else if (node_len < c->ranges[type].min_len || | |
259 | node_len > c->ranges[type].max_len) | |
260 | goto out_len; | |
261 | ||
18d1d7fb AB |
262 | if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->mounting && |
263 | !c->remounting_rw && c->no_chk_data_crc) | |
6f7ab6d4 | 264 | return 0; |
2953e73f | 265 | |
1e51764a AB |
266 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); |
267 | node_crc = le32_to_cpu(ch->crc); | |
268 | if (crc != node_crc) { | |
269 | if (!quiet) | |
235c362b | 270 | ubifs_err(c, "bad CRC: calculated %#08x, read %#08x", |
1e51764a AB |
271 | crc, node_crc); |
272 | err = -EUCLEAN; | |
273 | goto out; | |
274 | } | |
275 | ||
276 | return 0; | |
277 | ||
278 | out_len: | |
279 | if (!quiet) | |
235c362b | 280 | ubifs_err(c, "bad node length %d", node_len); |
1e51764a AB |
281 | out: |
282 | if (!quiet) { | |
235c362b | 283 | ubifs_err(c, "bad node at LEB %d:%d", lnum, offs); |
edf6be24 | 284 | ubifs_dump_node(c, buf); |
7c46d0ae | 285 | dump_stack(); |
1e51764a AB |
286 | } |
287 | return err; | |
288 | } | |
289 | ||
290 | /** | |
291 | * ubifs_pad - pad flash space. | |
292 | * @c: UBIFS file-system description object | |
293 | * @buf: buffer to put padding to | |
294 | * @pad: how many bytes to pad | |
295 | * | |
296 | * The flash media obliges us to write only in chunks of %c->min_io_size and | |
297 | * when we have to write less data we add padding node to the write-buffer and | |
298 | * pad it to the next minimal I/O unit's boundary. Padding nodes help when the | |
299 | * media is being scanned. If the amount of wasted space is not enough to fit a | |
300 | * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes | |
301 | * pattern (%UBIFS_PADDING_BYTE). | |
302 | * | |
303 | * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is | |
304 | * used. | |
305 | */ | |
306 | void ubifs_pad(const struct ubifs_info *c, void *buf, int pad) | |
307 | { | |
308 | uint32_t crc; | |
309 | ||
6eb61d58 | 310 | ubifs_assert(c, pad >= 0 && !(pad & 7)); |
1e51764a AB |
311 | |
312 | if (pad >= UBIFS_PAD_NODE_SZ) { | |
313 | struct ubifs_ch *ch = buf; | |
314 | struct ubifs_pad_node *pad_node = buf; | |
315 | ||
316 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); | |
317 | ch->node_type = UBIFS_PAD_NODE; | |
318 | ch->group_type = UBIFS_NO_NODE_GROUP; | |
319 | ch->padding[0] = ch->padding[1] = 0; | |
320 | ch->sqnum = 0; | |
321 | ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ); | |
322 | pad -= UBIFS_PAD_NODE_SZ; | |
323 | pad_node->pad_len = cpu_to_le32(pad); | |
324 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8); | |
325 | ch->crc = cpu_to_le32(crc); | |
326 | memset(buf + UBIFS_PAD_NODE_SZ, 0, pad); | |
327 | } else if (pad > 0) | |
328 | /* Too little space, padding node won't fit */ | |
329 | memset(buf, UBIFS_PADDING_BYTE, pad); | |
330 | } | |
331 | ||
332 | /** | |
333 | * next_sqnum - get next sequence number. | |
334 | * @c: UBIFS file-system description object | |
335 | */ | |
336 | static unsigned long long next_sqnum(struct ubifs_info *c) | |
337 | { | |
338 | unsigned long long sqnum; | |
339 | ||
340 | spin_lock(&c->cnt_lock); | |
341 | sqnum = ++c->max_sqnum; | |
342 | spin_unlock(&c->cnt_lock); | |
343 | ||
344 | if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) { | |
345 | if (sqnum >= SQNUM_WATERMARK) { | |
235c362b | 346 | ubifs_err(c, "sequence number overflow %llu, end of life", |
1e51764a AB |
347 | sqnum); |
348 | ubifs_ro_mode(c, -EINVAL); | |
349 | } | |
235c362b | 350 | ubifs_warn(c, "running out of sequence numbers, end of life soon"); |
1e51764a AB |
351 | } |
352 | ||
353 | return sqnum; | |
354 | } | |
355 | ||
dead9726 | 356 | void ubifs_init_node(struct ubifs_info *c, void *node, int len, int pad) |
1e51764a | 357 | { |
1e51764a AB |
358 | struct ubifs_ch *ch = node; |
359 | unsigned long long sqnum = next_sqnum(c); | |
360 | ||
6eb61d58 | 361 | ubifs_assert(c, len >= UBIFS_CH_SZ); |
1e51764a AB |
362 | |
363 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); | |
364 | ch->len = cpu_to_le32(len); | |
365 | ch->group_type = UBIFS_NO_NODE_GROUP; | |
366 | ch->sqnum = cpu_to_le64(sqnum); | |
367 | ch->padding[0] = ch->padding[1] = 0; | |
1e51764a AB |
368 | |
369 | if (pad) { | |
370 | len = ALIGN(len, 8); | |
371 | pad = ALIGN(len, c->min_io_size) - len; | |
372 | ubifs_pad(c, node + len, pad); | |
373 | } | |
374 | } | |
375 | ||
dead9726 SH |
376 | void ubifs_crc_node(struct ubifs_info *c, void *node, int len) |
377 | { | |
378 | struct ubifs_ch *ch = node; | |
379 | uint32_t crc; | |
380 | ||
381 | crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); | |
382 | ch->crc = cpu_to_le32(crc); | |
383 | } | |
384 | ||
a384b47e SH |
385 | /** |
386 | * ubifs_prepare_node_hmac - prepare node to be written to flash. | |
387 | * @c: UBIFS file-system description object | |
388 | * @node: the node to pad | |
389 | * @len: node length | |
390 | * @hmac_offs: offset of the HMAC in the node | |
391 | * @pad: if the buffer has to be padded | |
392 | * | |
393 | * This function prepares node at @node to be written to the media - it | |
394 | * calculates node CRC, fills the common header, and adds proper padding up to | |
395 | * the next minimum I/O unit if @pad is not zero. if @hmac_offs is positive then | |
396 | * a HMAC is inserted into the node at the given offset. | |
397 | * | |
398 | * This function returns 0 for success or a negative error code otherwise. | |
399 | */ | |
400 | int ubifs_prepare_node_hmac(struct ubifs_info *c, void *node, int len, | |
401 | int hmac_offs, int pad) | |
402 | { | |
403 | int err; | |
404 | ||
405 | ubifs_init_node(c, node, len, pad); | |
406 | ||
407 | if (hmac_offs > 0) { | |
408 | err = ubifs_node_insert_hmac(c, node, len, hmac_offs); | |
409 | if (err) | |
410 | return err; | |
411 | } | |
412 | ||
413 | ubifs_crc_node(c, node, len); | |
414 | ||
415 | return 0; | |
416 | } | |
417 | ||
dead9726 SH |
418 | /** |
419 | * ubifs_prepare_node - prepare node to be written to flash. | |
420 | * @c: UBIFS file-system description object | |
421 | * @node: the node to pad | |
422 | * @len: node length | |
423 | * @pad: if the buffer has to be padded | |
424 | * | |
425 | * This function prepares node at @node to be written to the media - it | |
426 | * calculates node CRC, fills the common header, and adds proper padding up to | |
427 | * the next minimum I/O unit if @pad is not zero. | |
428 | */ | |
429 | void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad) | |
430 | { | |
a384b47e SH |
431 | /* |
432 | * Deliberately ignore return value since this function can only fail | |
433 | * when a hmac offset is given. | |
434 | */ | |
435 | ubifs_prepare_node_hmac(c, node, len, 0, pad); | |
dead9726 SH |
436 | } |
437 | ||
1e51764a AB |
438 | /** |
439 | * ubifs_prep_grp_node - prepare node of a group to be written to flash. | |
440 | * @c: UBIFS file-system description object | |
441 | * @node: the node to pad | |
442 | * @len: node length | |
443 | * @last: indicates the last node of the group | |
444 | * | |
445 | * This function prepares node at @node to be written to the media - it | |
446 | * calculates node CRC and fills the common header. | |
447 | */ | |
448 | void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last) | |
449 | { | |
450 | uint32_t crc; | |
451 | struct ubifs_ch *ch = node; | |
452 | unsigned long long sqnum = next_sqnum(c); | |
453 | ||
6eb61d58 | 454 | ubifs_assert(c, len >= UBIFS_CH_SZ); |
1e51764a AB |
455 | |
456 | ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); | |
457 | ch->len = cpu_to_le32(len); | |
458 | if (last) | |
459 | ch->group_type = UBIFS_LAST_OF_NODE_GROUP; | |
460 | else | |
461 | ch->group_type = UBIFS_IN_NODE_GROUP; | |
462 | ch->sqnum = cpu_to_le64(sqnum); | |
463 | ch->padding[0] = ch->padding[1] = 0; | |
464 | crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); | |
465 | ch->crc = cpu_to_le32(crc); | |
466 | } | |
467 | ||
468 | /** | |
469 | * wbuf_timer_callback - write-buffer timer callback function. | |
39274a1e | 470 | * @timer: timer data (write-buffer descriptor) |
1e51764a AB |
471 | * |
472 | * This function is called when the write-buffer timer expires. | |
473 | */ | |
f2c5dbd7 | 474 | static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) |
1e51764a | 475 | { |
f2c5dbd7 | 476 | struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer); |
1e51764a | 477 | |
77a7ae58 | 478 | dbg_io("jhead %s", dbg_jhead(wbuf->jhead)); |
1e51764a AB |
479 | wbuf->need_sync = 1; |
480 | wbuf->c->need_wbuf_sync = 1; | |
481 | ubifs_wake_up_bgt(wbuf->c); | |
f2c5dbd7 | 482 | return HRTIMER_NORESTART; |
1e51764a AB |
483 | } |
484 | ||
485 | /** | |
486 | * new_wbuf_timer - start new write-buffer timer. | |
6eb61d58 | 487 | * @c: UBIFS file-system description object |
1e51764a AB |
488 | * @wbuf: write-buffer descriptor |
489 | */ | |
6eb61d58 | 490 | static void new_wbuf_timer_nolock(struct ubifs_info *c, struct ubifs_wbuf *wbuf) |
1e51764a | 491 | { |
1b7fc2c0 RM |
492 | ktime_t softlimit = ms_to_ktime(dirty_writeback_interval * 10); |
493 | unsigned long long delta = dirty_writeback_interval; | |
854826c9 | 494 | |
1b7fc2c0 RM |
495 | /* centi to milli, milli to nano, then 10% */ |
496 | delta *= 10ULL * NSEC_PER_MSEC / 10ULL; | |
854826c9 | 497 | |
6eb61d58 RW |
498 | ubifs_assert(c, !hrtimer_active(&wbuf->timer)); |
499 | ubifs_assert(c, delta <= ULONG_MAX); | |
1e51764a | 500 | |
0b335b9d | 501 | if (wbuf->no_timer) |
1e51764a | 502 | return; |
77a7ae58 AB |
503 | dbg_io("set timer for jhead %s, %llu-%llu millisecs", |
504 | dbg_jhead(wbuf->jhead), | |
854826c9 RM |
505 | div_u64(ktime_to_ns(softlimit), USEC_PER_SEC), |
506 | div_u64(ktime_to_ns(softlimit) + delta, USEC_PER_SEC)); | |
507 | hrtimer_start_range_ns(&wbuf->timer, softlimit, delta, | |
f2c5dbd7 | 508 | HRTIMER_MODE_REL); |
1e51764a AB |
509 | } |
510 | ||
511 | /** | |
512 | * cancel_wbuf_timer - cancel write-buffer timer. | |
513 | * @wbuf: write-buffer descriptor | |
514 | */ | |
515 | static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) | |
516 | { | |
0b335b9d AB |
517 | if (wbuf->no_timer) |
518 | return; | |
1e51764a | 519 | wbuf->need_sync = 0; |
f2c5dbd7 | 520 | hrtimer_cancel(&wbuf->timer); |
1e51764a AB |
521 | } |
522 | ||
523 | /** | |
524 | * ubifs_wbuf_sync_nolock - synchronize write-buffer. | |
525 | * @wbuf: write-buffer to synchronize | |
526 | * | |
527 | * This function synchronizes write-buffer @buf and returns zero in case of | |
528 | * success or a negative error code in case of failure. | |
6c7f74f7 AB |
529 | * |
530 | * Note, although write-buffers are of @c->max_write_size, this function does | |
531 | * not necessarily writes all @c->max_write_size bytes to the flash. Instead, | |
532 | * if the write-buffer is only partially filled with data, only the used part | |
533 | * of the write-buffer (aligned on @c->min_io_size boundary) is synchronized. | |
534 | * This way we waste less space. | |
1e51764a AB |
535 | */ |
536 | int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) | |
537 | { | |
538 | struct ubifs_info *c = wbuf->c; | |
6c7f74f7 | 539 | int err, dirt, sync_len; |
1e51764a AB |
540 | |
541 | cancel_wbuf_timer_nolock(wbuf); | |
542 | if (!wbuf->used || wbuf->lnum == -1) | |
543 | /* Write-buffer is empty or not seeked */ | |
544 | return 0; | |
545 | ||
77a7ae58 AB |
546 | dbg_io("LEB %d:%d, %d bytes, jhead %s", |
547 | wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead)); | |
6eb61d58 RW |
548 | ubifs_assert(c, !(wbuf->avail & 7)); |
549 | ubifs_assert(c, wbuf->offs + wbuf->size <= c->leb_size); | |
550 | ubifs_assert(c, wbuf->size >= c->min_io_size); | |
551 | ubifs_assert(c, wbuf->size <= c->max_write_size); | |
552 | ubifs_assert(c, wbuf->size % c->min_io_size == 0); | |
553 | ubifs_assert(c, !c->ro_media && !c->ro_mount); | |
6c7f74f7 | 554 | if (c->leb_size - wbuf->offs >= c->max_write_size) |
6eb61d58 | 555 | ubifs_assert(c, !((wbuf->offs + wbuf->size) % c->max_write_size)); |
1e51764a | 556 | |
2680d722 | 557 | if (c->ro_error) |
1e51764a AB |
558 | return -EROFS; |
559 | ||
6c7f74f7 AB |
560 | /* |
561 | * Do not write whole write buffer but write only the minimum necessary | |
562 | * amount of min. I/O units. | |
563 | */ | |
564 | sync_len = ALIGN(wbuf->used, c->min_io_size); | |
565 | dirt = sync_len - wbuf->used; | |
566 | if (dirt) | |
567 | ubifs_pad(c, wbuf->buf + wbuf->used, dirt); | |
b36a261e | 568 | err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, sync_len); |
987226a5 | 569 | if (err) |
1e51764a | 570 | return err; |
1e51764a | 571 | |
1e51764a | 572 | spin_lock(&wbuf->lock); |
6c7f74f7 AB |
573 | wbuf->offs += sync_len; |
574 | /* | |
575 | * Now @wbuf->offs is not necessarily aligned to @c->max_write_size. | |
576 | * But our goal is to optimize writes and make sure we write in | |
577 | * @c->max_write_size chunks and to @c->max_write_size-aligned offset. | |
578 | * Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make | |
579 | * sure that @wbuf->offs + @wbuf->size is aligned to | |
580 | * @c->max_write_size. This way we make sure that after next | |
581 | * write-buffer flush we are again at the optimal offset (aligned to | |
582 | * @c->max_write_size). | |
583 | */ | |
584 | if (c->leb_size - wbuf->offs < c->max_write_size) | |
585 | wbuf->size = c->leb_size - wbuf->offs; | |
586 | else if (wbuf->offs & (c->max_write_size - 1)) | |
587 | wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; | |
588 | else | |
589 | wbuf->size = c->max_write_size; | |
590 | wbuf->avail = wbuf->size; | |
1e51764a AB |
591 | wbuf->used = 0; |
592 | wbuf->next_ino = 0; | |
593 | spin_unlock(&wbuf->lock); | |
594 | ||
595 | if (wbuf->sync_callback) | |
596 | err = wbuf->sync_callback(c, wbuf->lnum, | |
597 | c->leb_size - wbuf->offs, dirt); | |
598 | return err; | |
599 | } | |
600 | ||
601 | /** | |
602 | * ubifs_wbuf_seek_nolock - seek write-buffer. | |
603 | * @wbuf: write-buffer | |
604 | * @lnum: logical eraseblock number to seek to | |
605 | * @offs: logical eraseblock offset to seek to | |
1e51764a | 606 | * |
cb54ef8b | 607 | * This function targets the write-buffer to logical eraseblock @lnum:@offs. |
cb14a184 AB |
608 | * The write-buffer has to be empty. Returns zero in case of success and a |
609 | * negative error code in case of failure. | |
1e51764a | 610 | */ |
b36a261e | 611 | int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs) |
1e51764a AB |
612 | { |
613 | const struct ubifs_info *c = wbuf->c; | |
614 | ||
77a7ae58 | 615 | dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead)); |
6eb61d58 RW |
616 | ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt); |
617 | ubifs_assert(c, offs >= 0 && offs <= c->leb_size); | |
618 | ubifs_assert(c, offs % c->min_io_size == 0 && !(offs & 7)); | |
619 | ubifs_assert(c, lnum != wbuf->lnum); | |
620 | ubifs_assert(c, wbuf->used == 0); | |
1e51764a AB |
621 | |
622 | spin_lock(&wbuf->lock); | |
623 | wbuf->lnum = lnum; | |
624 | wbuf->offs = offs; | |
6c7f74f7 AB |
625 | if (c->leb_size - wbuf->offs < c->max_write_size) |
626 | wbuf->size = c->leb_size - wbuf->offs; | |
627 | else if (wbuf->offs & (c->max_write_size - 1)) | |
628 | wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; | |
629 | else | |
630 | wbuf->size = c->max_write_size; | |
631 | wbuf->avail = wbuf->size; | |
1e51764a AB |
632 | wbuf->used = 0; |
633 | spin_unlock(&wbuf->lock); | |
1e51764a AB |
634 | |
635 | return 0; | |
636 | } | |
637 | ||
638 | /** | |
639 | * ubifs_bg_wbufs_sync - synchronize write-buffers. | |
640 | * @c: UBIFS file-system description object | |
641 | * | |
642 | * This function is called by background thread to synchronize write-buffers. | |
643 | * Returns zero in case of success and a negative error code in case of | |
644 | * failure. | |
645 | */ | |
646 | int ubifs_bg_wbufs_sync(struct ubifs_info *c) | |
647 | { | |
648 | int err, i; | |
649 | ||
6eb61d58 | 650 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
1e51764a AB |
651 | if (!c->need_wbuf_sync) |
652 | return 0; | |
653 | c->need_wbuf_sync = 0; | |
654 | ||
2680d722 | 655 | if (c->ro_error) { |
1e51764a AB |
656 | err = -EROFS; |
657 | goto out_timers; | |
658 | } | |
659 | ||
660 | dbg_io("synchronize"); | |
661 | for (i = 0; i < c->jhead_cnt; i++) { | |
662 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; | |
663 | ||
664 | cond_resched(); | |
665 | ||
666 | /* | |
667 | * If the mutex is locked then wbuf is being changed, so | |
668 | * synchronization is not necessary. | |
669 | */ | |
670 | if (mutex_is_locked(&wbuf->io_mutex)) | |
671 | continue; | |
672 | ||
673 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); | |
674 | if (!wbuf->need_sync) { | |
675 | mutex_unlock(&wbuf->io_mutex); | |
676 | continue; | |
677 | } | |
678 | ||
679 | err = ubifs_wbuf_sync_nolock(wbuf); | |
680 | mutex_unlock(&wbuf->io_mutex); | |
681 | if (err) { | |
235c362b | 682 | ubifs_err(c, "cannot sync write-buffer, error %d", err); |
1e51764a AB |
683 | ubifs_ro_mode(c, err); |
684 | goto out_timers; | |
685 | } | |
686 | } | |
687 | ||
688 | return 0; | |
689 | ||
690 | out_timers: | |
691 | /* Cancel all timers to prevent repeated errors */ | |
692 | for (i = 0; i < c->jhead_cnt; i++) { | |
693 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; | |
694 | ||
695 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); | |
696 | cancel_wbuf_timer_nolock(wbuf); | |
697 | mutex_unlock(&wbuf->io_mutex); | |
698 | } | |
699 | return err; | |
700 | } | |
701 | ||
702 | /** | |
703 | * ubifs_wbuf_write_nolock - write data to flash via write-buffer. | |
704 | * @wbuf: write-buffer | |
705 | * @buf: node to write | |
706 | * @len: node length | |
707 | * | |
708 | * This function writes data to flash via write-buffer @wbuf. This means that | |
709 | * the last piece of the node won't reach the flash media immediately if it | |
6c7f74f7 AB |
710 | * does not take whole max. write unit (@c->max_write_size). Instead, the node |
711 | * will sit in RAM until the write-buffer is synchronized (e.g., by timer, or | |
712 | * because more data are appended to the write-buffer). | |
1e51764a AB |
713 | * |
714 | * This function returns zero in case of success and a negative error code in | |
715 | * case of failure. If the node cannot be written because there is no more | |
716 | * space in this logical eraseblock, %-ENOSPC is returned. | |
717 | */ | |
718 | int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) | |
719 | { | |
720 | struct ubifs_info *c = wbuf->c; | |
12f33891 | 721 | int err, written, n, aligned_len = ALIGN(len, 8); |
1e51764a | 722 | |
77a7ae58 AB |
723 | dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len, |
724 | dbg_ntype(((struct ubifs_ch *)buf)->node_type), | |
725 | dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used); | |
6eb61d58 RW |
726 | ubifs_assert(c, len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); |
727 | ubifs_assert(c, wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); | |
728 | ubifs_assert(c, !(wbuf->offs & 7) && wbuf->offs <= c->leb_size); | |
729 | ubifs_assert(c, wbuf->avail > 0 && wbuf->avail <= wbuf->size); | |
730 | ubifs_assert(c, wbuf->size >= c->min_io_size); | |
731 | ubifs_assert(c, wbuf->size <= c->max_write_size); | |
732 | ubifs_assert(c, wbuf->size % c->min_io_size == 0); | |
733 | ubifs_assert(c, mutex_is_locked(&wbuf->io_mutex)); | |
734 | ubifs_assert(c, !c->ro_media && !c->ro_mount); | |
735 | ubifs_assert(c, !c->space_fixup); | |
6c7f74f7 | 736 | if (c->leb_size - wbuf->offs >= c->max_write_size) |
6eb61d58 | 737 | ubifs_assert(c, !((wbuf->offs + wbuf->size) % c->max_write_size)); |
1e51764a AB |
738 | |
739 | if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { | |
740 | err = -ENOSPC; | |
741 | goto out; | |
742 | } | |
743 | ||
744 | cancel_wbuf_timer_nolock(wbuf); | |
745 | ||
2680d722 | 746 | if (c->ro_error) |
1e51764a AB |
747 | return -EROFS; |
748 | ||
749 | if (aligned_len <= wbuf->avail) { | |
750 | /* | |
751 | * The node is not very large and fits entirely within | |
752 | * write-buffer. | |
753 | */ | |
754 | memcpy(wbuf->buf + wbuf->used, buf, len); | |
755 | ||
756 | if (aligned_len == wbuf->avail) { | |
77a7ae58 AB |
757 | dbg_io("flush jhead %s wbuf to LEB %d:%d", |
758 | dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); | |
987226a5 | 759 | err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, |
b36a261e | 760 | wbuf->offs, wbuf->size); |
1e51764a AB |
761 | if (err) |
762 | goto out; | |
763 | ||
764 | spin_lock(&wbuf->lock); | |
6c7f74f7 AB |
765 | wbuf->offs += wbuf->size; |
766 | if (c->leb_size - wbuf->offs >= c->max_write_size) | |
767 | wbuf->size = c->max_write_size; | |
768 | else | |
769 | wbuf->size = c->leb_size - wbuf->offs; | |
770 | wbuf->avail = wbuf->size; | |
1e51764a AB |
771 | wbuf->used = 0; |
772 | wbuf->next_ino = 0; | |
773 | spin_unlock(&wbuf->lock); | |
774 | } else { | |
775 | spin_lock(&wbuf->lock); | |
776 | wbuf->avail -= aligned_len; | |
777 | wbuf->used += aligned_len; | |
778 | spin_unlock(&wbuf->lock); | |
779 | } | |
780 | ||
781 | goto exit; | |
782 | } | |
783 | ||
6c7f74f7 | 784 | written = 0; |
1e51764a | 785 | |
6c7f74f7 AB |
786 | if (wbuf->used) { |
787 | /* | |
788 | * The node is large enough and does not fit entirely within | |
789 | * current available space. We have to fill and flush | |
790 | * write-buffer and switch to the next max. write unit. | |
791 | */ | |
792 | dbg_io("flush jhead %s wbuf to LEB %d:%d", | |
793 | dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); | |
794 | memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); | |
987226a5 | 795 | err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, |
b36a261e | 796 | wbuf->size); |
6c7f74f7 AB |
797 | if (err) |
798 | goto out; | |
799 | ||
12f33891 | 800 | wbuf->offs += wbuf->size; |
6c7f74f7 AB |
801 | len -= wbuf->avail; |
802 | aligned_len -= wbuf->avail; | |
803 | written += wbuf->avail; | |
804 | } else if (wbuf->offs & (c->max_write_size - 1)) { | |
805 | /* | |
806 | * The write-buffer offset is not aligned to | |
807 | * @c->max_write_size and @wbuf->size is less than | |
808 | * @c->max_write_size. Write @wbuf->size bytes to make sure the | |
809 | * following writes are done in optimal @c->max_write_size | |
810 | * chunks. | |
811 | */ | |
812 | dbg_io("write %d bytes to LEB %d:%d", | |
813 | wbuf->size, wbuf->lnum, wbuf->offs); | |
987226a5 | 814 | err = ubifs_leb_write(c, wbuf->lnum, buf, wbuf->offs, |
b36a261e | 815 | wbuf->size); |
6c7f74f7 AB |
816 | if (err) |
817 | goto out; | |
818 | ||
12f33891 | 819 | wbuf->offs += wbuf->size; |
6c7f74f7 AB |
820 | len -= wbuf->size; |
821 | aligned_len -= wbuf->size; | |
822 | written += wbuf->size; | |
823 | } | |
1e51764a AB |
824 | |
825 | /* | |
6c7f74f7 AB |
826 | * The remaining data may take more whole max. write units, so write the |
827 | * remains multiple to max. write unit size directly to the flash media. | |
1e51764a AB |
828 | * We align node length to 8-byte boundary because we anyway flash wbuf |
829 | * if the remaining space is less than 8 bytes. | |
830 | */ | |
6c7f74f7 | 831 | n = aligned_len >> c->max_write_shift; |
1e51764a | 832 | if (n) { |
6c7f74f7 | 833 | n <<= c->max_write_shift; |
12f33891 AB |
834 | dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, |
835 | wbuf->offs); | |
987226a5 | 836 | err = ubifs_leb_write(c, wbuf->lnum, buf + written, |
b36a261e | 837 | wbuf->offs, n); |
1e51764a AB |
838 | if (err) |
839 | goto out; | |
12f33891 | 840 | wbuf->offs += n; |
1e51764a AB |
841 | aligned_len -= n; |
842 | len -= n; | |
843 | written += n; | |
844 | } | |
845 | ||
846 | spin_lock(&wbuf->lock); | |
847 | if (aligned_len) | |
848 | /* | |
849 | * And now we have what's left and what does not take whole | |
6c7f74f7 | 850 | * max. write unit, so write it to the write-buffer and we are |
1e51764a AB |
851 | * done. |
852 | */ | |
853 | memcpy(wbuf->buf, buf + written, len); | |
854 | ||
6c7f74f7 AB |
855 | if (c->leb_size - wbuf->offs >= c->max_write_size) |
856 | wbuf->size = c->max_write_size; | |
857 | else | |
858 | wbuf->size = c->leb_size - wbuf->offs; | |
859 | wbuf->avail = wbuf->size - aligned_len; | |
1e51764a | 860 | wbuf->used = aligned_len; |
1e51764a AB |
861 | wbuf->next_ino = 0; |
862 | spin_unlock(&wbuf->lock); | |
863 | ||
864 | exit: | |
865 | if (wbuf->sync_callback) { | |
866 | int free = c->leb_size - wbuf->offs - wbuf->used; | |
867 | ||
868 | err = wbuf->sync_callback(c, wbuf->lnum, free, 0); | |
869 | if (err) | |
870 | goto out; | |
871 | } | |
872 | ||
873 | if (wbuf->used) | |
6eb61d58 | 874 | new_wbuf_timer_nolock(c, wbuf); |
1e51764a AB |
875 | |
876 | return 0; | |
877 | ||
878 | out: | |
235c362b | 879 | ubifs_err(c, "cannot write %d bytes to LEB %d:%d, error %d", |
1e51764a | 880 | len, wbuf->lnum, wbuf->offs, err); |
edf6be24 | 881 | ubifs_dump_node(c, buf); |
7c46d0ae | 882 | dump_stack(); |
edf6be24 | 883 | ubifs_dump_leb(c, wbuf->lnum); |
1e51764a AB |
884 | return err; |
885 | } | |
886 | ||
887 | /** | |
a384b47e | 888 | * ubifs_write_node_hmac - write node to the media. |
1e51764a AB |
889 | * @c: UBIFS file-system description object |
890 | * @buf: the node to write | |
891 | * @len: node length | |
892 | * @lnum: logical eraseblock number | |
893 | * @offs: offset within the logical eraseblock | |
a384b47e | 894 | * @hmac_offs: offset of the HMAC within the node |
1e51764a AB |
895 | * |
896 | * This function automatically fills node magic number, assigns sequence | |
897 | * number, and calculates node CRC checksum. The length of the @buf buffer has | |
898 | * to be aligned to the minimal I/O unit size. This function automatically | |
899 | * appends padding node and padding bytes if needed. Returns zero in case of | |
900 | * success and a negative error code in case of failure. | |
901 | */ | |
a384b47e SH |
902 | int ubifs_write_node_hmac(struct ubifs_info *c, void *buf, int len, int lnum, |
903 | int offs, int hmac_offs) | |
1e51764a AB |
904 | { |
905 | int err, buf_len = ALIGN(len, c->min_io_size); | |
906 | ||
907 | dbg_io("LEB %d:%d, %s, length %d (aligned %d)", | |
908 | lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len, | |
909 | buf_len); | |
6eb61d58 RW |
910 | ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
911 | ubifs_assert(c, offs % c->min_io_size == 0 && offs < c->leb_size); | |
912 | ubifs_assert(c, !c->ro_media && !c->ro_mount); | |
913 | ubifs_assert(c, !c->space_fixup); | |
1e51764a | 914 | |
2680d722 | 915 | if (c->ro_error) |
1e51764a AB |
916 | return -EROFS; |
917 | ||
a384b47e SH |
918 | err = ubifs_prepare_node_hmac(c, buf, len, hmac_offs, 1); |
919 | if (err) | |
920 | return err; | |
921 | ||
b36a261e | 922 | err = ubifs_leb_write(c, lnum, buf, offs, buf_len); |
987226a5 | 923 | if (err) |
edf6be24 | 924 | ubifs_dump_node(c, buf); |
1e51764a AB |
925 | |
926 | return err; | |
927 | } | |
928 | ||
a384b47e SH |
929 | /** |
930 | * ubifs_write_node - write node to the media. | |
931 | * @c: UBIFS file-system description object | |
932 | * @buf: the node to write | |
933 | * @len: node length | |
934 | * @lnum: logical eraseblock number | |
935 | * @offs: offset within the logical eraseblock | |
936 | * | |
937 | * This function automatically fills node magic number, assigns sequence | |
938 | * number, and calculates node CRC checksum. The length of the @buf buffer has | |
939 | * to be aligned to the minimal I/O unit size. This function automatically | |
940 | * appends padding node and padding bytes if needed. Returns zero in case of | |
941 | * success and a negative error code in case of failure. | |
942 | */ | |
943 | int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, | |
944 | int offs) | |
945 | { | |
946 | return ubifs_write_node_hmac(c, buf, len, lnum, offs, -1); | |
947 | } | |
948 | ||
1e51764a AB |
949 | /** |
950 | * ubifs_read_node_wbuf - read node from the media or write-buffer. | |
951 | * @wbuf: wbuf to check for un-written data | |
952 | * @buf: buffer to read to | |
953 | * @type: node type | |
954 | * @len: node length | |
955 | * @lnum: logical eraseblock number | |
956 | * @offs: offset within the logical eraseblock | |
957 | * | |
958 | * This function reads a node of known type and length, checks it and stores | |
959 | * in @buf. If the node partially or fully sits in the write-buffer, this | |
960 | * function takes data from the buffer, otherwise it reads the flash media. | |
961 | * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative | |
962 | * error code in case of failure. | |
963 | */ | |
964 | int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, | |
965 | int lnum, int offs) | |
966 | { | |
967 | const struct ubifs_info *c = wbuf->c; | |
968 | int err, rlen, overlap; | |
969 | struct ubifs_ch *ch = buf; | |
970 | ||
77a7ae58 AB |
971 | dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs, |
972 | dbg_ntype(type), len, dbg_jhead(wbuf->jhead)); | |
6eb61d58 RW |
973 | ubifs_assert(c, wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
974 | ubifs_assert(c, !(offs & 7) && offs < c->leb_size); | |
975 | ubifs_assert(c, type >= 0 && type < UBIFS_NODE_TYPES_CNT); | |
1e51764a AB |
976 | |
977 | spin_lock(&wbuf->lock); | |
978 | overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); | |
979 | if (!overlap) { | |
980 | /* We may safely unlock the write-buffer and read the data */ | |
981 | spin_unlock(&wbuf->lock); | |
982 | return ubifs_read_node(c, buf, type, len, lnum, offs); | |
983 | } | |
984 | ||
985 | /* Don't read under wbuf */ | |
986 | rlen = wbuf->offs - offs; | |
987 | if (rlen < 0) | |
988 | rlen = 0; | |
989 | ||
990 | /* Copy the rest from the write-buffer */ | |
991 | memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); | |
992 | spin_unlock(&wbuf->lock); | |
993 | ||
994 | if (rlen > 0) { | |
995 | /* Read everything that goes before write-buffer */ | |
d304820a AB |
996 | err = ubifs_leb_read(c, lnum, buf, offs, rlen, 0); |
997 | if (err && err != -EBADMSG) | |
1e51764a | 998 | return err; |
1e51764a AB |
999 | } |
1000 | ||
1001 | if (type != ch->node_type) { | |
235c362b | 1002 | ubifs_err(c, "bad node type (%d but expected %d)", |
1e51764a AB |
1003 | ch->node_type, type); |
1004 | goto out; | |
1005 | } | |
1006 | ||
2953e73f | 1007 | err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
1e51764a | 1008 | if (err) { |
235c362b | 1009 | ubifs_err(c, "expected node type %d", type); |
1e51764a AB |
1010 | return err; |
1011 | } | |
1012 | ||
1013 | rlen = le32_to_cpu(ch->len); | |
1014 | if (rlen != len) { | |
235c362b | 1015 | ubifs_err(c, "bad node length %d, expected %d", rlen, len); |
1e51764a AB |
1016 | goto out; |
1017 | } | |
1018 | ||
1019 | return 0; | |
1020 | ||
1021 | out: | |
235c362b | 1022 | ubifs_err(c, "bad node at LEB %d:%d", lnum, offs); |
edf6be24 | 1023 | ubifs_dump_node(c, buf); |
7c46d0ae | 1024 | dump_stack(); |
1e51764a AB |
1025 | return -EINVAL; |
1026 | } | |
1027 | ||
1028 | /** | |
1029 | * ubifs_read_node - read node. | |
1030 | * @c: UBIFS file-system description object | |
1031 | * @buf: buffer to read to | |
1032 | * @type: node type | |
1033 | * @len: node length (not aligned) | |
1034 | * @lnum: logical eraseblock number | |
1035 | * @offs: offset within the logical eraseblock | |
1036 | * | |
1037 | * This function reads a node of known type and and length, checks it and | |
1038 | * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched | |
1039 | * and a negative error code in case of failure. | |
1040 | */ | |
1041 | int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, | |
1042 | int lnum, int offs) | |
1043 | { | |
1044 | int err, l; | |
1045 | struct ubifs_ch *ch = buf; | |
1046 | ||
1047 | dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); | |
6eb61d58 RW |
1048 | ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
1049 | ubifs_assert(c, len >= UBIFS_CH_SZ && offs + len <= c->leb_size); | |
1050 | ubifs_assert(c, !(offs & 7) && offs < c->leb_size); | |
1051 | ubifs_assert(c, type >= 0 && type < UBIFS_NODE_TYPES_CNT); | |
1e51764a | 1052 | |
d304820a AB |
1053 | err = ubifs_leb_read(c, lnum, buf, offs, len, 0); |
1054 | if (err && err != -EBADMSG) | |
1e51764a | 1055 | return err; |
1e51764a AB |
1056 | |
1057 | if (type != ch->node_type) { | |
90bea5a3 DG |
1058 | ubifs_errc(c, "bad node type (%d but expected %d)", |
1059 | ch->node_type, type); | |
1e51764a AB |
1060 | goto out; |
1061 | } | |
1062 | ||
2953e73f | 1063 | err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
1e51764a | 1064 | if (err) { |
90bea5a3 | 1065 | ubifs_errc(c, "expected node type %d", type); |
1e51764a AB |
1066 | return err; |
1067 | } | |
1068 | ||
1069 | l = le32_to_cpu(ch->len); | |
1070 | if (l != len) { | |
90bea5a3 | 1071 | ubifs_errc(c, "bad node length %d, expected %d", l, len); |
1e51764a AB |
1072 | goto out; |
1073 | } | |
1074 | ||
1075 | return 0; | |
1076 | ||
1077 | out: | |
90bea5a3 DG |
1078 | ubifs_errc(c, "bad node at LEB %d:%d, LEB mapping status %d", lnum, |
1079 | offs, ubi_is_mapped(c->ubi, lnum)); | |
1080 | if (!c->probing) { | |
1081 | ubifs_dump_node(c, buf); | |
1082 | dump_stack(); | |
1083 | } | |
1e51764a AB |
1084 | return -EINVAL; |
1085 | } | |
1086 | ||
1087 | /** | |
1088 | * ubifs_wbuf_init - initialize write-buffer. | |
1089 | * @c: UBIFS file-system description object | |
1090 | * @wbuf: write-buffer to initialize | |
1091 | * | |
cb54ef8b | 1092 | * This function initializes write-buffer. Returns zero in case of success |
1e51764a AB |
1093 | * %-ENOMEM in case of failure. |
1094 | */ | |
1095 | int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) | |
1096 | { | |
1097 | size_t size; | |
1098 | ||
6c7f74f7 | 1099 | wbuf->buf = kmalloc(c->max_write_size, GFP_KERNEL); |
1e51764a AB |
1100 | if (!wbuf->buf) |
1101 | return -ENOMEM; | |
1102 | ||
6c7f74f7 | 1103 | size = (c->max_write_size / UBIFS_CH_SZ + 1) * sizeof(ino_t); |
1e51764a AB |
1104 | wbuf->inodes = kmalloc(size, GFP_KERNEL); |
1105 | if (!wbuf->inodes) { | |
1106 | kfree(wbuf->buf); | |
1107 | wbuf->buf = NULL; | |
1108 | return -ENOMEM; | |
1109 | } | |
1110 | ||
1111 | wbuf->used = 0; | |
1112 | wbuf->lnum = wbuf->offs = -1; | |
6c7f74f7 AB |
1113 | /* |
1114 | * If the LEB starts at the max. write size aligned address, then | |
1115 | * write-buffer size has to be set to @c->max_write_size. Otherwise, | |
1116 | * set it to something smaller so that it ends at the closest max. | |
1117 | * write size boundary. | |
1118 | */ | |
1119 | size = c->max_write_size - (c->leb_start % c->max_write_size); | |
1120 | wbuf->avail = wbuf->size = size; | |
1e51764a AB |
1121 | wbuf->sync_callback = NULL; |
1122 | mutex_init(&wbuf->io_mutex); | |
1123 | spin_lock_init(&wbuf->lock); | |
1e51764a | 1124 | wbuf->c = c; |
1e51764a AB |
1125 | wbuf->next_ino = 0; |
1126 | ||
f2c5dbd7 AB |
1127 | hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1128 | wbuf->timer.function = wbuf_timer_callback_nolock; | |
1e51764a AB |
1129 | return 0; |
1130 | } | |
1131 | ||
1132 | /** | |
1133 | * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array. | |
cb54ef8b | 1134 | * @wbuf: the write-buffer where to add |
1e51764a AB |
1135 | * @inum: the inode number |
1136 | * | |
1137 | * This function adds an inode number to the inode array of the write-buffer. | |
1138 | */ | |
1139 | void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum) | |
1140 | { | |
1141 | if (!wbuf->buf) | |
1142 | /* NOR flash or something similar */ | |
1143 | return; | |
1144 | ||
1145 | spin_lock(&wbuf->lock); | |
1146 | if (wbuf->used) | |
1147 | wbuf->inodes[wbuf->next_ino++] = inum; | |
1148 | spin_unlock(&wbuf->lock); | |
1149 | } | |
1150 | ||
1151 | /** | |
1152 | * wbuf_has_ino - returns if the wbuf contains data from the inode. | |
1153 | * @wbuf: the write-buffer | |
1154 | * @inum: the inode number | |
1155 | * | |
1156 | * This function returns with %1 if the write-buffer contains some data from the | |
1157 | * given inode otherwise it returns with %0. | |
1158 | */ | |
1159 | static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum) | |
1160 | { | |
1161 | int i, ret = 0; | |
1162 | ||
1163 | spin_lock(&wbuf->lock); | |
1164 | for (i = 0; i < wbuf->next_ino; i++) | |
1165 | if (inum == wbuf->inodes[i]) { | |
1166 | ret = 1; | |
1167 | break; | |
1168 | } | |
1169 | spin_unlock(&wbuf->lock); | |
1170 | ||
1171 | return ret; | |
1172 | } | |
1173 | ||
1174 | /** | |
1175 | * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode. | |
1176 | * @c: UBIFS file-system description object | |
1177 | * @inode: inode to synchronize | |
1178 | * | |
1179 | * This function synchronizes write-buffers which contain nodes belonging to | |
1180 | * @inode. Returns zero in case of success and a negative error code in case of | |
1181 | * failure. | |
1182 | */ | |
1183 | int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode) | |
1184 | { | |
1185 | int i, err = 0; | |
1186 | ||
1187 | for (i = 0; i < c->jhead_cnt; i++) { | |
1188 | struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; | |
1189 | ||
1190 | if (i == GCHD) | |
1191 | /* | |
1192 | * GC head is special, do not look at it. Even if the | |
1193 | * head contains something related to this inode, it is | |
1194 | * a _copy_ of corresponding on-flash node which sits | |
1195 | * somewhere else. | |
1196 | */ | |
1197 | continue; | |
1198 | ||
1199 | if (!wbuf_has_ino(wbuf, inode->i_ino)) | |
1200 | continue; | |
1201 | ||
1202 | mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); | |
1203 | if (wbuf_has_ino(wbuf, inode->i_ino)) | |
1204 | err = ubifs_wbuf_sync_nolock(wbuf); | |
1205 | mutex_unlock(&wbuf->io_mutex); | |
1206 | ||
1207 | if (err) { | |
1208 | ubifs_ro_mode(c, err); | |
1209 | return err; | |
1210 | } | |
1211 | } | |
1212 | return 0; | |
1213 | } |