blob: 77e9b874b6c22d4105186116c5092bcbbb7f5de0 [file] [log] [blame]
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
21 */
22
23/*
24 * This file implements functions needed to recover from unclean un-mounts.
25 * When UBIFS is mounted, it checks a flag on the master node to determine if
André Goddard Rosaaf901ca2009-11-14 13:09:05 -020026 * an un-mount was completed successfully. If not, the process of mounting
Artem Bityutskiy6fb43742010-05-23 15:20:21 +030027 * incorporates additional checking and fixing of on-flash data structures.
Artem Bityutskiy1e517642008-07-14 19:08:37 +030028 * UBIFS always cleans away all remnants of an unclean un-mount, so that
29 * errors do not accumulate. However UBIFS defers recovery if it is mounted
30 * read-only, and the flash is not modified in that case.
31 */
32
33#include <linux/crc32.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090034#include <linux/slab.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030035#include "ubifs.h"
36
37/**
38 * is_empty - determine whether a buffer is empty (contains all 0xff).
39 * @buf: buffer to clean
40 * @len: length of buffer
41 *
42 * This function returns %1 if the buffer is empty (contains all 0xff) otherwise
43 * %0 is returned.
44 */
45static int is_empty(void *buf, int len)
46{
47 uint8_t *p = buf;
48 int i;
49
50 for (i = 0; i < len; i++)
51 if (*p++ != 0xff)
52 return 0;
53 return 1;
54}
55
56/**
Artem Bityutskiy06112542009-06-29 19:27:14 +030057 * first_non_ff - find offset of the first non-0xff byte.
58 * @buf: buffer to search in
59 * @len: length of buffer
60 *
61 * This function returns offset of the first non-0xff byte in @buf or %-1 if
62 * the buffer contains only 0xff bytes.
63 */
64static int first_non_ff(void *buf, int len)
65{
66 uint8_t *p = buf;
67 int i;
68
69 for (i = 0; i < len; i++)
70 if (*p++ != 0xff)
71 return i;
72 return -1;
73}
74
75/**
Artem Bityutskiy1e517642008-07-14 19:08:37 +030076 * get_master_node - get the last valid master node allowing for corruption.
77 * @c: UBIFS file-system description object
78 * @lnum: LEB number
79 * @pbuf: buffer containing the LEB read, is returned here
80 * @mst: master node, if found, is returned here
81 * @cor: corruption, if found, is returned here
82 *
83 * This function allocates a buffer, reads the LEB into it, and finds and
84 * returns the last valid master node allowing for one area of corruption.
85 * The corrupt area, if there is one, must be consistent with the assumption
86 * that it is the result of an unclean unmount while the master node was being
87 * written. Under those circumstances, it is valid to use the previously written
88 * master node.
89 *
90 * This function returns %0 on success and a negative error code on failure.
91 */
92static int get_master_node(const struct ubifs_info *c, int lnum, void **pbuf,
93 struct ubifs_mst_node **mst, void **cor)
94{
95 const int sz = c->mst_node_alsz;
96 int err, offs, len;
97 void *sbuf, *buf;
98
99 sbuf = vmalloc(c->leb_size);
100 if (!sbuf)
101 return -ENOMEM;
102
103 err = ubi_read(c->ubi, lnum, sbuf, 0, c->leb_size);
104 if (err && err != -EBADMSG)
105 goto out_free;
106
107 /* Find the first position that is definitely not a node */
108 offs = 0;
109 buf = sbuf;
110 len = c->leb_size;
111 while (offs + UBIFS_MST_NODE_SZ <= c->leb_size) {
112 struct ubifs_ch *ch = buf;
113
114 if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC)
115 break;
116 offs += sz;
117 buf += sz;
118 len -= sz;
119 }
120 /* See if there was a valid master node before that */
121 if (offs) {
122 int ret;
123
124 offs -= sz;
125 buf -= sz;
126 len += sz;
127 ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
128 if (ret != SCANNED_A_NODE && offs) {
129 /* Could have been corruption so check one place back */
130 offs -= sz;
131 buf -= sz;
132 len += sz;
133 ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
134 if (ret != SCANNED_A_NODE)
135 /*
136 * We accept only one area of corruption because
137 * we are assuming that it was caused while
138 * trying to write a master node.
139 */
140 goto out_err;
141 }
142 if (ret == SCANNED_A_NODE) {
143 struct ubifs_ch *ch = buf;
144
145 if (ch->node_type != UBIFS_MST_NODE)
146 goto out_err;
147 dbg_rcvry("found a master node at %d:%d", lnum, offs);
148 *mst = buf;
149 offs += sz;
150 buf += sz;
151 len -= sz;
152 }
153 }
154 /* Check for corruption */
155 if (offs < c->leb_size) {
156 if (!is_empty(buf, min_t(int, len, sz))) {
157 *cor = buf;
158 dbg_rcvry("found corruption at %d:%d", lnum, offs);
159 }
160 offs += sz;
161 buf += sz;
162 len -= sz;
163 }
164 /* Check remaining empty space */
165 if (offs < c->leb_size)
166 if (!is_empty(buf, len))
167 goto out_err;
168 *pbuf = sbuf;
169 return 0;
170
171out_err:
172 err = -EINVAL;
173out_free:
174 vfree(sbuf);
175 *mst = NULL;
176 *cor = NULL;
177 return err;
178}
179
180/**
181 * write_rcvrd_mst_node - write recovered master node.
182 * @c: UBIFS file-system description object
183 * @mst: master node
184 *
185 * This function returns %0 on success and a negative error code on failure.
186 */
187static int write_rcvrd_mst_node(struct ubifs_info *c,
188 struct ubifs_mst_node *mst)
189{
190 int err = 0, lnum = UBIFS_MST_LNUM, sz = c->mst_node_alsz;
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700191 __le32 save_flags;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300192
193 dbg_rcvry("recovery");
194
195 save_flags = mst->flags;
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700196 mst->flags |= cpu_to_le32(UBIFS_MST_RCVRY);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300197
198 ubifs_prepare_node(c, mst, UBIFS_MST_NODE_SZ, 1);
199 err = ubi_leb_change(c->ubi, lnum, mst, sz, UBI_SHORTTERM);
200 if (err)
201 goto out;
202 err = ubi_leb_change(c->ubi, lnum + 1, mst, sz, UBI_SHORTTERM);
203 if (err)
204 goto out;
205out:
206 mst->flags = save_flags;
207 return err;
208}
209
210/**
211 * ubifs_recover_master_node - recover the master node.
212 * @c: UBIFS file-system description object
213 *
214 * This function recovers the master node from corruption that may occur due to
215 * an unclean unmount.
216 *
217 * This function returns %0 on success and a negative error code on failure.
218 */
219int ubifs_recover_master_node(struct ubifs_info *c)
220{
221 void *buf1 = NULL, *buf2 = NULL, *cor1 = NULL, *cor2 = NULL;
222 struct ubifs_mst_node *mst1 = NULL, *mst2 = NULL, *mst;
223 const int sz = c->mst_node_alsz;
224 int err, offs1, offs2;
225
226 dbg_rcvry("recovery");
227
228 err = get_master_node(c, UBIFS_MST_LNUM, &buf1, &mst1, &cor1);
229 if (err)
230 goto out_free;
231
232 err = get_master_node(c, UBIFS_MST_LNUM + 1, &buf2, &mst2, &cor2);
233 if (err)
234 goto out_free;
235
236 if (mst1) {
237 offs1 = (void *)mst1 - buf1;
238 if ((le32_to_cpu(mst1->flags) & UBIFS_MST_RCVRY) &&
239 (offs1 == 0 && !cor1)) {
240 /*
241 * mst1 was written by recovery at offset 0 with no
242 * corruption.
243 */
244 dbg_rcvry("recovery recovery");
245 mst = mst1;
246 } else if (mst2) {
247 offs2 = (void *)mst2 - buf2;
248 if (offs1 == offs2) {
249 /* Same offset, so must be the same */
250 if (memcmp((void *)mst1 + UBIFS_CH_SZ,
251 (void *)mst2 + UBIFS_CH_SZ,
252 UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
253 goto out_err;
254 mst = mst1;
255 } else if (offs2 + sz == offs1) {
256 /* 1st LEB was written, 2nd was not */
257 if (cor1)
258 goto out_err;
259 mst = mst1;
260 } else if (offs1 == 0 && offs2 + sz >= c->leb_size) {
261 /* 1st LEB was unmapped and written, 2nd not */
262 if (cor1)
263 goto out_err;
264 mst = mst1;
265 } else
266 goto out_err;
267 } else {
268 /*
269 * 2nd LEB was unmapped and about to be written, so
270 * there must be only one master node in the first LEB
271 * and no corruption.
272 */
273 if (offs1 != 0 || cor1)
274 goto out_err;
275 mst = mst1;
276 }
277 } else {
278 if (!mst2)
279 goto out_err;
280 /*
281 * 1st LEB was unmapped and about to be written, so there must
282 * be no room left in 2nd LEB.
283 */
284 offs2 = (void *)mst2 - buf2;
285 if (offs2 + sz + sz <= c->leb_size)
286 goto out_err;
287 mst = mst2;
288 }
289
Artem Bityutskiy348709b2009-08-25 15:00:55 +0300290 ubifs_msg("recovered master node from LEB %d",
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300291 (mst == mst1 ? UBIFS_MST_LNUM : UBIFS_MST_LNUM + 1));
292
293 memcpy(c->mst_node, mst, UBIFS_MST_NODE_SZ);
294
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300295 if (c->ro_mount) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300296 /* Read-only mode. Keep a copy for switching to rw mode */
297 c->rcvrd_mst_node = kmalloc(sz, GFP_KERNEL);
298 if (!c->rcvrd_mst_node) {
299 err = -ENOMEM;
300 goto out_free;
301 }
302 memcpy(c->rcvrd_mst_node, c->mst_node, UBIFS_MST_NODE_SZ);
303 } else {
304 /* Write the recovered master node */
305 c->max_sqnum = le64_to_cpu(mst->ch.sqnum) - 1;
306 err = write_rcvrd_mst_node(c, c->mst_node);
307 if (err)
308 goto out_free;
309 }
310
311 vfree(buf2);
312 vfree(buf1);
313
314 return 0;
315
316out_err:
317 err = -EINVAL;
318out_free:
319 ubifs_err("failed to recover master node");
320 if (mst1) {
321 dbg_err("dumping first master node");
322 dbg_dump_node(c, mst1);
323 }
324 if (mst2) {
325 dbg_err("dumping second master node");
326 dbg_dump_node(c, mst2);
327 }
328 vfree(buf2);
329 vfree(buf1);
330 return err;
331}
332
333/**
334 * ubifs_write_rcvrd_mst_node - write the recovered master node.
335 * @c: UBIFS file-system description object
336 *
337 * This function writes the master node that was recovered during mounting in
338 * read-only mode and must now be written because we are remounting rw.
339 *
340 * This function returns %0 on success and a negative error code on failure.
341 */
342int ubifs_write_rcvrd_mst_node(struct ubifs_info *c)
343{
344 int err;
345
346 if (!c->rcvrd_mst_node)
347 return 0;
348 c->rcvrd_mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
349 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
350 err = write_rcvrd_mst_node(c, c->rcvrd_mst_node);
351 if (err)
352 return err;
353 kfree(c->rcvrd_mst_node);
354 c->rcvrd_mst_node = NULL;
355 return 0;
356}
357
358/**
359 * is_last_write - determine if an offset was in the last write to a LEB.
360 * @c: UBIFS file-system description object
361 * @buf: buffer to check
362 * @offs: offset to check
363 *
364 * This function returns %1 if @offs was in the last write to the LEB whose data
365 * is in @buf, otherwise %0 is returned. The determination is made by checking
Artem Bityutskiy428ff9d2009-05-25 16:59:28 +0300366 * for subsequent empty space starting from the next @c->min_io_size boundary.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300367 */
368static int is_last_write(const struct ubifs_info *c, void *buf, int offs)
369{
Artem Bityutskiy428ff9d2009-05-25 16:59:28 +0300370 int empty_offs, check_len;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300371 uint8_t *p;
372
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300373 /*
Artem Bityutskiy428ff9d2009-05-25 16:59:28 +0300374 * Round up to the next @c->min_io_size boundary i.e. @offs is in the
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300375 * last wbuf written. After that should be empty space.
376 */
377 empty_offs = ALIGN(offs + 1, c->min_io_size);
378 check_len = c->leb_size - empty_offs;
379 p = buf + empty_offs - offs;
Artem Bityutskiy431102f2009-06-29 18:58:34 +0300380 return is_empty(p, check_len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300381}
382
383/**
384 * clean_buf - clean the data from an LEB sitting in a buffer.
385 * @c: UBIFS file-system description object
386 * @buf: buffer to clean
387 * @lnum: LEB number to clean
388 * @offs: offset from which to clean
389 * @len: length of buffer
390 *
391 * This function pads up to the next min_io_size boundary (if there is one) and
392 * sets empty space to all 0xff. @buf, @offs and @len are updated to the next
Artem Bityutskiy428ff9d2009-05-25 16:59:28 +0300393 * @c->min_io_size boundary.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300394 */
395static void clean_buf(const struct ubifs_info *c, void **buf, int lnum,
396 int *offs, int *len)
397{
398 int empty_offs, pad_len;
399
400 lnum = lnum;
401 dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs);
402
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300403 ubifs_assert(!(*offs & 7));
404 empty_offs = ALIGN(*offs, c->min_io_size);
405 pad_len = empty_offs - *offs;
406 ubifs_pad(c, *buf, pad_len);
407 *offs += pad_len;
408 *buf += pad_len;
409 *len -= pad_len;
410 memset(*buf, 0xff, c->leb_size - empty_offs);
411}
412
413/**
414 * no_more_nodes - determine if there are no more nodes in a buffer.
415 * @c: UBIFS file-system description object
416 * @buf: buffer to check
417 * @len: length of buffer
418 * @lnum: LEB number of the LEB from which @buf was read
419 * @offs: offset from which @buf was read
420 *
Adrian Hunterde097572009-03-20 11:09:04 +0100421 * This function ensures that the corrupted node at @offs is the last thing
422 * written to a LEB. This function returns %1 if more data is not found and
423 * %0 if more data is found.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300424 */
425static int no_more_nodes(const struct ubifs_info *c, void *buf, int len,
426 int lnum, int offs)
427{
Adrian Hunterde097572009-03-20 11:09:04 +0100428 struct ubifs_ch *ch = buf;
429 int skip, dlen = le32_to_cpu(ch->len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300430
Adrian Hunterde097572009-03-20 11:09:04 +0100431 /* Check for empty space after the corrupt node's common header */
432 skip = ALIGN(offs + UBIFS_CH_SZ, c->min_io_size) - offs;
433 if (is_empty(buf + skip, len - skip))
434 return 1;
435 /*
436 * The area after the common header size is not empty, so the common
437 * header must be intact. Check it.
438 */
439 if (ubifs_check_node(c, buf, lnum, offs, 1, 0) != -EUCLEAN) {
440 dbg_rcvry("unexpected bad common header at %d:%d", lnum, offs);
441 return 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300442 }
Adrian Hunterde097572009-03-20 11:09:04 +0100443 /* Now we know the corrupt node's length we can skip over it */
444 skip = ALIGN(offs + dlen, c->min_io_size) - offs;
445 /* After which there should be empty space */
446 if (is_empty(buf + skip, len - skip))
447 return 1;
448 dbg_rcvry("unexpected data at %d:%d", lnum, offs + skip);
449 return 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300450}
451
452/**
453 * fix_unclean_leb - fix an unclean LEB.
454 * @c: UBIFS file-system description object
455 * @sleb: scanned LEB information
456 * @start: offset where scan started
457 */
458static int fix_unclean_leb(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
459 int start)
460{
461 int lnum = sleb->lnum, endpt = start;
462
463 /* Get the end offset of the last node we are keeping */
464 if (!list_empty(&sleb->nodes)) {
465 struct ubifs_scan_node *snod;
466
467 snod = list_entry(sleb->nodes.prev,
468 struct ubifs_scan_node, list);
469 endpt = snod->offs + snod->len;
470 }
471
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300472 if (c->ro_mount && !c->remounting_rw) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300473 /* Add to recovery list */
474 struct ubifs_unclean_leb *ucleb;
475
476 dbg_rcvry("need to fix LEB %d start %d endpt %d",
477 lnum, start, sleb->endpt);
478 ucleb = kzalloc(sizeof(struct ubifs_unclean_leb), GFP_NOFS);
479 if (!ucleb)
480 return -ENOMEM;
481 ucleb->lnum = lnum;
482 ucleb->endpt = endpt;
483 list_add_tail(&ucleb->list, &c->unclean_leb_list);
484 } else {
485 /* Write the fixed LEB back to flash */
486 int err;
487
488 dbg_rcvry("fixing LEB %d start %d endpt %d",
489 lnum, start, sleb->endpt);
490 if (endpt == 0) {
491 err = ubifs_leb_unmap(c, lnum);
492 if (err)
493 return err;
494 } else {
495 int len = ALIGN(endpt, c->min_io_size);
496
497 if (start) {
498 err = ubi_read(c->ubi, lnum, sleb->buf, 0,
499 start);
500 if (err)
501 return err;
502 }
503 /* Pad to min_io_size */
504 if (len > endpt) {
505 int pad_len = len - ALIGN(endpt, 8);
506
507 if (pad_len > 0) {
508 void *buf = sleb->buf + len - pad_len;
509
510 ubifs_pad(c, buf, pad_len);
511 }
512 }
513 err = ubi_leb_change(c->ubi, lnum, sleb->buf, len,
514 UBI_UNKNOWN);
515 if (err)
516 return err;
517 }
518 }
519 return 0;
520}
521
522/**
523 * drop_incomplete_group - drop nodes from an incomplete group.
524 * @sleb: scanned LEB information
525 * @offs: offset of dropped nodes is returned here
526 *
527 * This function returns %1 if nodes are dropped and %0 otherwise.
528 */
529static int drop_incomplete_group(struct ubifs_scan_leb *sleb, int *offs)
530{
531 int dropped = 0;
532
533 while (!list_empty(&sleb->nodes)) {
534 struct ubifs_scan_node *snod;
535 struct ubifs_ch *ch;
536
537 snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
538 list);
539 ch = snod->node;
540 if (ch->group_type != UBIFS_IN_NODE_GROUP)
541 return dropped;
542 dbg_rcvry("dropping node at %d:%d", sleb->lnum, snod->offs);
543 *offs = snod->offs;
544 list_del(&snod->list);
545 kfree(snod);
546 sleb->nodes_cnt -= 1;
547 dropped = 1;
548 }
549 return dropped;
550}
551
552/**
553 * ubifs_recover_leb - scan and recover a LEB.
554 * @c: UBIFS file-system description object
555 * @lnum: LEB number
556 * @offs: offset
557 * @sbuf: LEB-sized buffer to use
558 * @grouped: nodes may be grouped for recovery
559 *
560 * This function does a scan of a LEB, but caters for errors that might have
561 * been caused by the unclean unmount from which we are attempting to recover.
Artem Bityutskiyed43f2f2009-06-29 17:59:23 +0300562 * Returns %0 in case of success, %-EUCLEAN if an unrecoverable corruption is
563 * found, and a negative error code in case of failure.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300564 */
565struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
566 int offs, void *sbuf, int grouped)
567{
568 int err, len = c->leb_size - offs, need_clean = 0, quiet = 1;
569 int empty_chkd = 0, start = offs;
570 struct ubifs_scan_leb *sleb;
571 void *buf = sbuf + offs;
572
573 dbg_rcvry("%d:%d", lnum, offs);
574
575 sleb = ubifs_start_scan(c, lnum, offs, sbuf);
576 if (IS_ERR(sleb))
577 return sleb;
578
579 if (sleb->ecc)
580 need_clean = 1;
581
582 while (len >= 8) {
583 int ret;
584
585 dbg_scan("look at LEB %d:%d (%d bytes left)",
586 lnum, offs, len);
587
588 cond_resched();
589
590 /*
591 * Scan quietly until there is an error from which we cannot
592 * recover
593 */
594 ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
595
596 if (ret == SCANNED_A_NODE) {
597 /* A valid node, and not a padding node */
598 struct ubifs_ch *ch = buf;
599 int node_len;
600
601 err = ubifs_add_snod(c, sleb, buf, offs);
602 if (err)
603 goto error;
604 node_len = ALIGN(le32_to_cpu(ch->len), 8);
605 offs += node_len;
606 buf += node_len;
607 len -= node_len;
608 continue;
609 }
610
611 if (ret > 0) {
612 /* Padding bytes or a valid padding node */
613 offs += ret;
614 buf += ret;
615 len -= ret;
616 continue;
617 }
618
619 if (ret == SCANNED_EMPTY_SPACE) {
620 if (!is_empty(buf, len)) {
621 if (!is_last_write(c, buf, offs))
622 break;
623 clean_buf(c, &buf, lnum, &offs, &len);
624 need_clean = 1;
625 }
626 empty_chkd = 1;
627 break;
628 }
629
630 if (ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE)
631 if (is_last_write(c, buf, offs)) {
632 clean_buf(c, &buf, lnum, &offs, &len);
633 need_clean = 1;
634 empty_chkd = 1;
635 break;
636 }
637
638 if (ret == SCANNED_A_CORRUPT_NODE)
639 if (no_more_nodes(c, buf, len, lnum, offs)) {
640 clean_buf(c, &buf, lnum, &offs, &len);
641 need_clean = 1;
642 empty_chkd = 1;
643 break;
644 }
645
646 if (quiet) {
647 /* Redo the last scan but noisily */
648 quiet = 0;
649 continue;
650 }
651
652 switch (ret) {
653 case SCANNED_GARBAGE:
654 dbg_err("garbage");
655 goto corrupted;
656 case SCANNED_A_CORRUPT_NODE:
657 case SCANNED_A_BAD_PAD_NODE:
658 dbg_err("bad node");
659 goto corrupted;
660 default:
661 dbg_err("unknown");
Artem Bityutskiyed43f2f2009-06-29 17:59:23 +0300662 err = -EINVAL;
663 goto error;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300664 }
665 }
666
667 if (!empty_chkd && !is_empty(buf, len)) {
668 if (is_last_write(c, buf, offs)) {
669 clean_buf(c, &buf, lnum, &offs, &len);
670 need_clean = 1;
671 } else {
Artem Bityutskiy06112542009-06-29 19:27:14 +0300672 int corruption = first_non_ff(buf, len);
673
674 ubifs_err("corrupt empty space LEB %d:%d, corruption "
675 "starts at %d", lnum, offs, corruption);
676 /* Make sure we dump interesting non-0xFF data */
677 offs = corruption;
678 buf += corruption;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300679 goto corrupted;
680 }
681 }
682
683 /* Drop nodes from incomplete group */
684 if (grouped && drop_incomplete_group(sleb, &offs)) {
685 buf = sbuf + offs;
686 len = c->leb_size - offs;
687 clean_buf(c, &buf, lnum, &offs, &len);
688 need_clean = 1;
689 }
690
691 if (offs % c->min_io_size) {
692 clean_buf(c, &buf, lnum, &offs, &len);
693 need_clean = 1;
694 }
695
696 ubifs_end_scan(c, sleb, lnum, offs);
697
698 if (need_clean) {
699 err = fix_unclean_leb(c, sleb, start);
700 if (err)
701 goto error;
702 }
703
704 return sleb;
705
706corrupted:
707 ubifs_scanned_corruption(c, lnum, offs, buf);
708 err = -EUCLEAN;
709error:
710 ubifs_err("LEB %d scanning failed", lnum);
711 ubifs_scan_destroy(sleb);
712 return ERR_PTR(err);
713}
714
715/**
716 * get_cs_sqnum - get commit start sequence number.
717 * @c: UBIFS file-system description object
718 * @lnum: LEB number of commit start node
719 * @offs: offset of commit start node
720 * @cs_sqnum: commit start sequence number is returned here
721 *
722 * This function returns %0 on success and a negative error code on failure.
723 */
724static int get_cs_sqnum(struct ubifs_info *c, int lnum, int offs,
725 unsigned long long *cs_sqnum)
726{
727 struct ubifs_cs_node *cs_node = NULL;
728 int err, ret;
729
730 dbg_rcvry("at %d:%d", lnum, offs);
731 cs_node = kmalloc(UBIFS_CS_NODE_SZ, GFP_KERNEL);
732 if (!cs_node)
733 return -ENOMEM;
734 if (c->leb_size - offs < UBIFS_CS_NODE_SZ)
735 goto out_err;
736 err = ubi_read(c->ubi, lnum, (void *)cs_node, offs, UBIFS_CS_NODE_SZ);
737 if (err && err != -EBADMSG)
738 goto out_free;
739 ret = ubifs_scan_a_node(c, cs_node, UBIFS_CS_NODE_SZ, lnum, offs, 0);
740 if (ret != SCANNED_A_NODE) {
741 dbg_err("Not a valid node");
742 goto out_err;
743 }
744 if (cs_node->ch.node_type != UBIFS_CS_NODE) {
745 dbg_err("Node a CS node, type is %d", cs_node->ch.node_type);
746 goto out_err;
747 }
748 if (le64_to_cpu(cs_node->cmt_no) != c->cmt_no) {
749 dbg_err("CS node cmt_no %llu != current cmt_no %llu",
750 (unsigned long long)le64_to_cpu(cs_node->cmt_no),
751 c->cmt_no);
752 goto out_err;
753 }
754 *cs_sqnum = le64_to_cpu(cs_node->ch.sqnum);
755 dbg_rcvry("commit start sqnum %llu", *cs_sqnum);
756 kfree(cs_node);
757 return 0;
758
759out_err:
760 err = -EINVAL;
761out_free:
762 ubifs_err("failed to get CS sqnum");
763 kfree(cs_node);
764 return err;
765}
766
767/**
768 * ubifs_recover_log_leb - scan and recover a log LEB.
769 * @c: UBIFS file-system description object
770 * @lnum: LEB number
771 * @offs: offset
772 * @sbuf: LEB-sized buffer to use
773 *
774 * This function does a scan of a LEB, but caters for errors that might have
Artem Bityutskiy7d08ae32010-10-17 15:50:19 +0300775 * been caused by unclean reboots from which we are attempting to recover
776 * (assume that only the last log LEB can be corrupted by an unclean reboot).
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300777 *
778 * This function returns %0 on success and a negative error code on failure.
779 */
780struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum,
781 int offs, void *sbuf)
782{
783 struct ubifs_scan_leb *sleb;
784 int next_lnum;
785
786 dbg_rcvry("LEB %d", lnum);
787 next_lnum = lnum + 1;
788 if (next_lnum >= UBIFS_LOG_LNUM + c->log_lebs)
789 next_lnum = UBIFS_LOG_LNUM;
790 if (next_lnum != c->ltail_lnum) {
791 /*
792 * We can only recover at the end of the log, so check that the
793 * next log LEB is empty or out of date.
794 */
Artem Bityutskiy348709b2009-08-25 15:00:55 +0300795 sleb = ubifs_scan(c, next_lnum, 0, sbuf, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300796 if (IS_ERR(sleb))
797 return sleb;
798 if (sleb->nodes_cnt) {
799 struct ubifs_scan_node *snod;
800 unsigned long long cs_sqnum = c->cs_sqnum;
801
802 snod = list_entry(sleb->nodes.next,
803 struct ubifs_scan_node, list);
804 if (cs_sqnum == 0) {
805 int err;
806
807 err = get_cs_sqnum(c, lnum, offs, &cs_sqnum);
808 if (err) {
809 ubifs_scan_destroy(sleb);
810 return ERR_PTR(err);
811 }
812 }
813 if (snod->sqnum > cs_sqnum) {
814 ubifs_err("unrecoverable log corruption "
815 "in LEB %d", lnum);
816 ubifs_scan_destroy(sleb);
817 return ERR_PTR(-EUCLEAN);
818 }
819 }
820 ubifs_scan_destroy(sleb);
821 }
822 return ubifs_recover_leb(c, lnum, offs, sbuf, 0);
823}
824
825/**
826 * recover_head - recover a head.
827 * @c: UBIFS file-system description object
828 * @lnum: LEB number of head to recover
829 * @offs: offset of head to recover
830 * @sbuf: LEB-sized buffer to use
831 *
832 * This function ensures that there is no data on the flash at a head location.
833 *
834 * This function returns %0 on success and a negative error code on failure.
835 */
836static int recover_head(const struct ubifs_info *c, int lnum, int offs,
837 void *sbuf)
838{
Artem Bityutskiy431102f2009-06-29 18:58:34 +0300839 int len, err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300840
841 if (c->min_io_size > 1)
842 len = c->min_io_size;
843 else
844 len = 512;
845 if (offs + len > c->leb_size)
846 len = c->leb_size - offs;
847
848 if (!len)
849 return 0;
850
851 /* Read at the head location and check it is empty flash */
852 err = ubi_read(c->ubi, lnum, sbuf, offs, len);
Artem Bityutskiy431102f2009-06-29 18:58:34 +0300853 if (err || !is_empty(sbuf, len)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300854 dbg_rcvry("cleaning head at %d:%d", lnum, offs);
855 if (offs == 0)
856 return ubifs_leb_unmap(c, lnum);
857 err = ubi_read(c->ubi, lnum, sbuf, 0, offs);
858 if (err)
859 return err;
860 return ubi_leb_change(c->ubi, lnum, sbuf, offs, UBI_UNKNOWN);
861 }
862
863 return 0;
864}
865
866/**
867 * ubifs_recover_inl_heads - recover index and LPT heads.
868 * @c: UBIFS file-system description object
869 * @sbuf: LEB-sized buffer to use
870 *
871 * This function ensures that there is no data on the flash at the index and
872 * LPT head locations.
873 *
874 * This deals with the recovery of a half-completed journal commit. UBIFS is
875 * careful never to overwrite the last version of the index or the LPT. Because
876 * the index and LPT are wandering trees, data from a half-completed commit will
877 * not be referenced anywhere in UBIFS. The data will be either in LEBs that are
878 * assumed to be empty and will be unmapped anyway before use, or in the index
879 * and LPT heads.
880 *
881 * This function returns %0 on success and a negative error code on failure.
882 */
883int ubifs_recover_inl_heads(const struct ubifs_info *c, void *sbuf)
884{
885 int err;
886
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300887 ubifs_assert(!c->ro_mount || c->remounting_rw);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300888
889 dbg_rcvry("checking index head at %d:%d", c->ihead_lnum, c->ihead_offs);
890 err = recover_head(c, c->ihead_lnum, c->ihead_offs, sbuf);
891 if (err)
892 return err;
893
894 dbg_rcvry("checking LPT head at %d:%d", c->nhead_lnum, c->nhead_offs);
895 err = recover_head(c, c->nhead_lnum, c->nhead_offs, sbuf);
896 if (err)
897 return err;
898
899 return 0;
900}
901
902/**
903 * clean_an_unclean_leb - read and write a LEB to remove corruption.
904 * @c: UBIFS file-system description object
905 * @ucleb: unclean LEB information
906 * @sbuf: LEB-sized buffer to use
907 *
908 * This function reads a LEB up to a point pre-determined by the mount recovery,
909 * checks the nodes, and writes the result back to the flash, thereby cleaning
910 * off any following corruption, or non-fatal ECC errors.
911 *
912 * This function returns %0 on success and a negative error code on failure.
913 */
914static int clean_an_unclean_leb(const struct ubifs_info *c,
915 struct ubifs_unclean_leb *ucleb, void *sbuf)
916{
917 int err, lnum = ucleb->lnum, offs = 0, len = ucleb->endpt, quiet = 1;
918 void *buf = sbuf;
919
920 dbg_rcvry("LEB %d len %d", lnum, len);
921
922 if (len == 0) {
923 /* Nothing to read, just unmap it */
924 err = ubifs_leb_unmap(c, lnum);
925 if (err)
926 return err;
927 return 0;
928 }
929
930 err = ubi_read(c->ubi, lnum, buf, offs, len);
931 if (err && err != -EBADMSG)
932 return err;
933
934 while (len >= 8) {
935 int ret;
936
937 cond_resched();
938
939 /* Scan quietly until there is an error */
940 ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
941
942 if (ret == SCANNED_A_NODE) {
943 /* A valid node, and not a padding node */
944 struct ubifs_ch *ch = buf;
945 int node_len;
946
947 node_len = ALIGN(le32_to_cpu(ch->len), 8);
948 offs += node_len;
949 buf += node_len;
950 len -= node_len;
951 continue;
952 }
953
954 if (ret > 0) {
955 /* Padding bytes or a valid padding node */
956 offs += ret;
957 buf += ret;
958 len -= ret;
959 continue;
960 }
961
962 if (ret == SCANNED_EMPTY_SPACE) {
963 ubifs_err("unexpected empty space at %d:%d",
964 lnum, offs);
965 return -EUCLEAN;
966 }
967
968 if (quiet) {
969 /* Redo the last scan but noisily */
970 quiet = 0;
971 continue;
972 }
973
974 ubifs_scanned_corruption(c, lnum, offs, buf);
975 return -EUCLEAN;
976 }
977
978 /* Pad to min_io_size */
979 len = ALIGN(ucleb->endpt, c->min_io_size);
980 if (len > ucleb->endpt) {
981 int pad_len = len - ALIGN(ucleb->endpt, 8);
982
983 if (pad_len > 0) {
984 buf = c->sbuf + len - pad_len;
985 ubifs_pad(c, buf, pad_len);
986 }
987 }
988
989 /* Write back the LEB atomically */
990 err = ubi_leb_change(c->ubi, lnum, sbuf, len, UBI_UNKNOWN);
991 if (err)
992 return err;
993
994 dbg_rcvry("cleaned LEB %d", lnum);
995
996 return 0;
997}
998
999/**
1000 * ubifs_clean_lebs - clean LEBs recovered during read-only mount.
1001 * @c: UBIFS file-system description object
1002 * @sbuf: LEB-sized buffer to use
1003 *
1004 * This function cleans a LEB identified during recovery that needs to be
1005 * written but was not because UBIFS was mounted read-only. This happens when
1006 * remounting to read-write mode.
1007 *
1008 * This function returns %0 on success and a negative error code on failure.
1009 */
1010int ubifs_clean_lebs(const struct ubifs_info *c, void *sbuf)
1011{
1012 dbg_rcvry("recovery");
1013 while (!list_empty(&c->unclean_leb_list)) {
1014 struct ubifs_unclean_leb *ucleb;
1015 int err;
1016
1017 ucleb = list_entry(c->unclean_leb_list.next,
1018 struct ubifs_unclean_leb, list);
1019 err = clean_an_unclean_leb(c, ucleb, sbuf);
1020 if (err)
1021 return err;
1022 list_del(&ucleb->list);
1023 kfree(ucleb);
1024 }
1025 return 0;
1026}
1027
1028/**
1029 * ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit.
1030 * @c: UBIFS file-system description object
1031 *
1032 * Out-of-place garbage collection requires always one empty LEB with which to
1033 * start garbage collection. The LEB number is recorded in c->gc_lnum and is
1034 * written to the master node on unmounting. In the case of an unclean unmount
1035 * the value of gc_lnum recorded in the master node is out of date and cannot
1036 * be used. Instead, recovery must allocate an empty LEB for this purpose.
1037 * However, there may not be enough empty space, in which case it must be
1038 * possible to GC the dirtiest LEB into the GC head LEB.
1039 *
1040 * This function also runs the commit which causes the TNC updates from
1041 * size-recovery and orphans to be written to the flash. That is important to
1042 * ensure correct replay order for subsequent mounts.
1043 *
1044 * This function returns %0 on success and a negative error code on failure.
1045 */
1046int ubifs_rcvry_gc_commit(struct ubifs_info *c)
1047{
1048 struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
1049 struct ubifs_lprops lp;
1050 int lnum, err;
1051
1052 c->gc_lnum = -1;
1053 if (wbuf->lnum == -1) {
1054 dbg_rcvry("no GC head LEB");
1055 goto find_free;
1056 }
1057 /*
1058 * See whether the used space in the dirtiest LEB fits in the GC head
1059 * LEB.
1060 */
1061 if (wbuf->offs == c->leb_size) {
1062 dbg_rcvry("no room in GC head LEB");
1063 goto find_free;
1064 }
1065 err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2);
1066 if (err) {
Artem Bityutskiy6fb43742010-05-23 15:20:21 +03001067 /*
1068 * There are no dirty or empty LEBs subject to here being
1069 * enough for the index. Try to use
1070 * 'ubifs_find_free_leb_for_idx()', which will return any empty
1071 * LEBs (ignoring index requirements). If the index then
1072 * doesn't have enough LEBs the recovery commit will fail -
1073 * which is the same result anyway i.e. recovery fails. So
1074 * there is no problem ignoring index requirements and just
1075 * grabbing a free LEB since we have already established there
1076 * is not a dirty LEB we could have used instead.
1077 */
1078 if (err == -ENOSPC) {
1079 dbg_rcvry("could not find a dirty LEB");
1080 goto find_free;
1081 }
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001082 return err;
1083 }
1084 ubifs_assert(!(lp.flags & LPROPS_INDEX));
1085 lnum = lp.lnum;
1086 if (lp.free + lp.dirty == c->leb_size) {
1087 /* An empty LEB was returned */
1088 if (lp.free != c->leb_size) {
1089 err = ubifs_change_one_lp(c, lnum, c->leb_size,
1090 0, 0, 0, 0);
1091 if (err)
1092 return err;
1093 }
1094 err = ubifs_leb_unmap(c, lnum);
1095 if (err)
1096 return err;
1097 c->gc_lnum = lnum;
1098 dbg_rcvry("allocated LEB %d for GC", lnum);
1099 /* Run the commit */
1100 dbg_rcvry("committing");
1101 return ubifs_run_commit(c);
1102 }
1103 /*
1104 * There was no empty LEB so the used space in the dirtiest LEB must fit
1105 * in the GC head LEB.
1106 */
1107 if (lp.free + lp.dirty < wbuf->offs) {
1108 dbg_rcvry("LEB %d doesn't fit in GC head LEB %d:%d",
1109 lnum, wbuf->lnum, wbuf->offs);
1110 err = ubifs_return_leb(c, lnum);
1111 if (err)
1112 return err;
1113 goto find_free;
1114 }
1115 /*
1116 * We run the commit before garbage collection otherwise subsequent
1117 * mounts will see the GC and orphan deletion in a different order.
1118 */
1119 dbg_rcvry("committing");
1120 err = ubifs_run_commit(c);
1121 if (err)
1122 return err;
1123 /*
1124 * The data in the dirtiest LEB fits in the GC head LEB, so do the GC
1125 * - use locking to keep 'ubifs_assert()' happy.
1126 */
1127 dbg_rcvry("GC'ing LEB %d", lnum);
1128 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
1129 err = ubifs_garbage_collect_leb(c, &lp);
1130 if (err >= 0) {
1131 int err2 = ubifs_wbuf_sync_nolock(wbuf);
1132
1133 if (err2)
1134 err = err2;
1135 }
1136 mutex_unlock(&wbuf->io_mutex);
1137 if (err < 0) {
1138 dbg_err("GC failed, error %d", err);
1139 if (err == -EAGAIN)
1140 err = -EINVAL;
1141 return err;
1142 }
1143 if (err != LEB_RETAINED) {
1144 dbg_err("GC returned %d", err);
1145 return -EINVAL;
1146 }
1147 err = ubifs_leb_unmap(c, c->gc_lnum);
1148 if (err)
1149 return err;
1150 dbg_rcvry("allocated LEB %d for GC", lnum);
1151 return 0;
1152
1153find_free:
1154 /*
1155 * There is no GC head LEB or the free space in the GC head LEB is too
Artem Bityutskiy6fb43742010-05-23 15:20:21 +03001156 * small, or there are not dirty LEBs. Allocate gc_lnum by calling
1157 * 'ubifs_find_free_leb_for_idx()' so GC is not run.
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001158 */
1159 lnum = ubifs_find_free_leb_for_idx(c);
1160 if (lnum < 0) {
1161 dbg_err("could not find an empty LEB");
1162 return lnum;
1163 }
1164 /* And reset the index flag */
1165 err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
1166 LPROPS_INDEX, 0);
1167 if (err)
1168 return err;
1169 c->gc_lnum = lnum;
1170 dbg_rcvry("allocated LEB %d for GC", lnum);
1171 /* Run the commit */
1172 dbg_rcvry("committing");
1173 return ubifs_run_commit(c);
1174}
1175
1176/**
1177 * struct size_entry - inode size information for recovery.
1178 * @rb: link in the RB-tree of sizes
1179 * @inum: inode number
1180 * @i_size: size on inode
1181 * @d_size: maximum size based on data nodes
1182 * @exists: indicates whether the inode exists
1183 * @inode: inode if pinned in memory awaiting rw mode to fix it
1184 */
1185struct size_entry {
1186 struct rb_node rb;
1187 ino_t inum;
1188 loff_t i_size;
1189 loff_t d_size;
1190 int exists;
1191 struct inode *inode;
1192};
1193
1194/**
1195 * add_ino - add an entry to the size tree.
1196 * @c: UBIFS file-system description object
1197 * @inum: inode number
1198 * @i_size: size on inode
1199 * @d_size: maximum size based on data nodes
1200 * @exists: indicates whether the inode exists
1201 */
1202static int add_ino(struct ubifs_info *c, ino_t inum, loff_t i_size,
1203 loff_t d_size, int exists)
1204{
1205 struct rb_node **p = &c->size_tree.rb_node, *parent = NULL;
1206 struct size_entry *e;
1207
1208 while (*p) {
1209 parent = *p;
1210 e = rb_entry(parent, struct size_entry, rb);
1211 if (inum < e->inum)
1212 p = &(*p)->rb_left;
1213 else
1214 p = &(*p)->rb_right;
1215 }
1216
1217 e = kzalloc(sizeof(struct size_entry), GFP_KERNEL);
1218 if (!e)
1219 return -ENOMEM;
1220
1221 e->inum = inum;
1222 e->i_size = i_size;
1223 e->d_size = d_size;
1224 e->exists = exists;
1225
1226 rb_link_node(&e->rb, parent, p);
1227 rb_insert_color(&e->rb, &c->size_tree);
1228
1229 return 0;
1230}
1231
1232/**
1233 * find_ino - find an entry on the size tree.
1234 * @c: UBIFS file-system description object
1235 * @inum: inode number
1236 */
1237static struct size_entry *find_ino(struct ubifs_info *c, ino_t inum)
1238{
1239 struct rb_node *p = c->size_tree.rb_node;
1240 struct size_entry *e;
1241
1242 while (p) {
1243 e = rb_entry(p, struct size_entry, rb);
1244 if (inum < e->inum)
1245 p = p->rb_left;
1246 else if (inum > e->inum)
1247 p = p->rb_right;
1248 else
1249 return e;
1250 }
1251 return NULL;
1252}
1253
1254/**
1255 * remove_ino - remove an entry from the size tree.
1256 * @c: UBIFS file-system description object
1257 * @inum: inode number
1258 */
1259static void remove_ino(struct ubifs_info *c, ino_t inum)
1260{
1261 struct size_entry *e = find_ino(c, inum);
1262
1263 if (!e)
1264 return;
1265 rb_erase(&e->rb, &c->size_tree);
1266 kfree(e);
1267}
1268
1269/**
1270 * ubifs_destroy_size_tree - free resources related to the size tree.
1271 * @c: UBIFS file-system description object
1272 */
1273void ubifs_destroy_size_tree(struct ubifs_info *c)
1274{
1275 struct rb_node *this = c->size_tree.rb_node;
1276 struct size_entry *e;
1277
1278 while (this) {
1279 if (this->rb_left) {
1280 this = this->rb_left;
1281 continue;
1282 } else if (this->rb_right) {
1283 this = this->rb_right;
1284 continue;
1285 }
1286 e = rb_entry(this, struct size_entry, rb);
1287 if (e->inode)
1288 iput(e->inode);
1289 this = rb_parent(this);
1290 if (this) {
1291 if (this->rb_left == &e->rb)
1292 this->rb_left = NULL;
1293 else
1294 this->rb_right = NULL;
1295 }
1296 kfree(e);
1297 }
1298 c->size_tree = RB_ROOT;
1299}
1300
1301/**
1302 * ubifs_recover_size_accum - accumulate inode sizes for recovery.
1303 * @c: UBIFS file-system description object
1304 * @key: node key
1305 * @deletion: node is for a deletion
1306 * @new_size: inode size
1307 *
1308 * This function has two purposes:
1309 * 1) to ensure there are no data nodes that fall outside the inode size
1310 * 2) to ensure there are no data nodes for inodes that do not exist
1311 * To accomplish those purposes, a rb-tree is constructed containing an entry
1312 * for each inode number in the journal that has not been deleted, and recording
1313 * the size from the inode node, the maximum size of any data node (also altered
1314 * by truncations) and a flag indicating a inode number for which no inode node
1315 * was present in the journal.
1316 *
1317 * Note that there is still the possibility that there are data nodes that have
1318 * been committed that are beyond the inode size, however the only way to find
1319 * them would be to scan the entire index. Alternatively, some provision could
1320 * be made to record the size of inodes at the start of commit, which would seem
1321 * very cumbersome for a scenario that is quite unlikely and the only negative
1322 * consequence of which is wasted space.
1323 *
1324 * This functions returns %0 on success and a negative error code on failure.
1325 */
1326int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key,
1327 int deletion, loff_t new_size)
1328{
1329 ino_t inum = key_inum(c, key);
1330 struct size_entry *e;
1331 int err;
1332
1333 switch (key_type(c, key)) {
1334 case UBIFS_INO_KEY:
1335 if (deletion)
1336 remove_ino(c, inum);
1337 else {
1338 e = find_ino(c, inum);
1339 if (e) {
1340 e->i_size = new_size;
1341 e->exists = 1;
1342 } else {
1343 err = add_ino(c, inum, new_size, 0, 1);
1344 if (err)
1345 return err;
1346 }
1347 }
1348 break;
1349 case UBIFS_DATA_KEY:
1350 e = find_ino(c, inum);
1351 if (e) {
1352 if (new_size > e->d_size)
1353 e->d_size = new_size;
1354 } else {
1355 err = add_ino(c, inum, 0, new_size, 0);
1356 if (err)
1357 return err;
1358 }
1359 break;
1360 case UBIFS_TRUN_KEY:
1361 e = find_ino(c, inum);
1362 if (e)
1363 e->d_size = new_size;
1364 break;
1365 }
1366 return 0;
1367}
1368
1369/**
1370 * fix_size_in_place - fix inode size in place on flash.
1371 * @c: UBIFS file-system description object
1372 * @e: inode size information for recovery
1373 */
1374static int fix_size_in_place(struct ubifs_info *c, struct size_entry *e)
1375{
1376 struct ubifs_ino_node *ino = c->sbuf;
1377 unsigned char *p;
1378 union ubifs_key key;
1379 int err, lnum, offs, len;
1380 loff_t i_size;
1381 uint32_t crc;
1382
1383 /* Locate the inode node LEB number and offset */
1384 ino_key_init(c, &key, e->inum);
1385 err = ubifs_tnc_locate(c, &key, ino, &lnum, &offs);
1386 if (err)
1387 goto out;
1388 /*
1389 * If the size recorded on the inode node is greater than the size that
1390 * was calculated from nodes in the journal then don't change the inode.
1391 */
1392 i_size = le64_to_cpu(ino->size);
1393 if (i_size >= e->d_size)
1394 return 0;
1395 /* Read the LEB */
1396 err = ubi_read(c->ubi, lnum, c->sbuf, 0, c->leb_size);
1397 if (err)
1398 goto out;
1399 /* Change the size field and recalculate the CRC */
1400 ino = c->sbuf + offs;
1401 ino->size = cpu_to_le64(e->d_size);
1402 len = le32_to_cpu(ino->ch.len);
1403 crc = crc32(UBIFS_CRC32_INIT, (void *)ino + 8, len - 8);
1404 ino->ch.crc = cpu_to_le32(crc);
1405 /* Work out where data in the LEB ends and free space begins */
1406 p = c->sbuf;
1407 len = c->leb_size - 1;
1408 while (p[len] == 0xff)
1409 len -= 1;
1410 len = ALIGN(len + 1, c->min_io_size);
1411 /* Atomically write the fixed LEB back again */
1412 err = ubi_leb_change(c->ubi, lnum, c->sbuf, len, UBI_UNKNOWN);
1413 if (err)
1414 goto out;
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001415 dbg_rcvry("inode %lu at %d:%d size %lld -> %lld ",
1416 (unsigned long)e->inum, lnum, offs, i_size, e->d_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001417 return 0;
1418
1419out:
1420 ubifs_warn("inode %lu failed to fix size %lld -> %lld error %d",
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001421 (unsigned long)e->inum, e->i_size, e->d_size, err);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001422 return err;
1423}
1424
1425/**
1426 * ubifs_recover_size - recover inode size.
1427 * @c: UBIFS file-system description object
1428 *
1429 * This function attempts to fix inode size discrepancies identified by the
1430 * 'ubifs_recover_size_accum()' function.
1431 *
1432 * This functions returns %0 on success and a negative error code on failure.
1433 */
1434int ubifs_recover_size(struct ubifs_info *c)
1435{
1436 struct rb_node *this = rb_first(&c->size_tree);
1437
1438 while (this) {
1439 struct size_entry *e;
1440 int err;
1441
1442 e = rb_entry(this, struct size_entry, rb);
1443 if (!e->exists) {
1444 union ubifs_key key;
1445
1446 ino_key_init(c, &key, e->inum);
1447 err = ubifs_tnc_lookup(c, &key, c->sbuf);
1448 if (err && err != -ENOENT)
1449 return err;
1450 if (err == -ENOENT) {
1451 /* Remove data nodes that have no inode */
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001452 dbg_rcvry("removing ino %lu",
1453 (unsigned long)e->inum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001454 err = ubifs_tnc_remove_ino(c, e->inum);
1455 if (err)
1456 return err;
1457 } else {
1458 struct ubifs_ino_node *ino = c->sbuf;
1459
1460 e->exists = 1;
1461 e->i_size = le64_to_cpu(ino->size);
1462 }
1463 }
1464 if (e->exists && e->i_size < e->d_size) {
Artem Bityutskiy2ef13292010-09-19 18:34:26 +03001465 if (!e->inode && c->ro_mount) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001466 /* Fix the inode size and pin it in memory */
1467 struct inode *inode;
1468
1469 inode = ubifs_iget(c->vfs_sb, e->inum);
1470 if (IS_ERR(inode))
1471 return PTR_ERR(inode);
1472 if (inode->i_size < e->d_size) {
1473 dbg_rcvry("ino %lu size %lld -> %lld",
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001474 (unsigned long)e->inum,
1475 e->d_size, inode->i_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001476 inode->i_size = e->d_size;
1477 ubifs_inode(inode)->ui_size = e->d_size;
1478 e->inode = inode;
1479 this = rb_next(this);
1480 continue;
1481 }
1482 iput(inode);
1483 } else {
1484 /* Fix the size in place */
1485 err = fix_size_in_place(c, e);
1486 if (err)
1487 return err;
1488 if (e->inode)
1489 iput(e->inode);
1490 }
1491 }
1492 this = rb_next(this);
1493 rb_erase(&e->rb, &c->size_tree);
1494 kfree(e);
1495 }
1496 return 0;
1497}