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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 Bityutskiy1e517642008-07-14 19:08:37 +030027 * incorparates additional checking and fixing of on-flash data structures.
28 * 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
295 if ((c->vfs_sb->s_flags & MS_RDONLY)) {
296 /* 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
472 if ((c->vfs_sb->s_flags & MS_RDONLY) && !c->remounting_rw) {
473 /* 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
775 * been caused by the unclean unmount from which we are attempting to recover.
776 *
777 * This function returns %0 on success and a negative error code on failure.
778 */
779struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum,
780 int offs, void *sbuf)
781{
782 struct ubifs_scan_leb *sleb;
783 int next_lnum;
784
785 dbg_rcvry("LEB %d", lnum);
786 next_lnum = lnum + 1;
787 if (next_lnum >= UBIFS_LOG_LNUM + c->log_lebs)
788 next_lnum = UBIFS_LOG_LNUM;
789 if (next_lnum != c->ltail_lnum) {
790 /*
791 * We can only recover at the end of the log, so check that the
792 * next log LEB is empty or out of date.
793 */
Artem Bityutskiy348709b2009-08-25 15:00:55 +0300794 sleb = ubifs_scan(c, next_lnum, 0, sbuf, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300795 if (IS_ERR(sleb))
796 return sleb;
797 if (sleb->nodes_cnt) {
798 struct ubifs_scan_node *snod;
799 unsigned long long cs_sqnum = c->cs_sqnum;
800
801 snod = list_entry(sleb->nodes.next,
802 struct ubifs_scan_node, list);
803 if (cs_sqnum == 0) {
804 int err;
805
806 err = get_cs_sqnum(c, lnum, offs, &cs_sqnum);
807 if (err) {
808 ubifs_scan_destroy(sleb);
809 return ERR_PTR(err);
810 }
811 }
812 if (snod->sqnum > cs_sqnum) {
813 ubifs_err("unrecoverable log corruption "
814 "in LEB %d", lnum);
815 ubifs_scan_destroy(sleb);
816 return ERR_PTR(-EUCLEAN);
817 }
818 }
819 ubifs_scan_destroy(sleb);
820 }
821 return ubifs_recover_leb(c, lnum, offs, sbuf, 0);
822}
823
824/**
825 * recover_head - recover a head.
826 * @c: UBIFS file-system description object
827 * @lnum: LEB number of head to recover
828 * @offs: offset of head to recover
829 * @sbuf: LEB-sized buffer to use
830 *
831 * This function ensures that there is no data on the flash at a head location.
832 *
833 * This function returns %0 on success and a negative error code on failure.
834 */
835static int recover_head(const struct ubifs_info *c, int lnum, int offs,
836 void *sbuf)
837{
Artem Bityutskiy431102f2009-06-29 18:58:34 +0300838 int len, err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300839
840 if (c->min_io_size > 1)
841 len = c->min_io_size;
842 else
843 len = 512;
844 if (offs + len > c->leb_size)
845 len = c->leb_size - offs;
846
847 if (!len)
848 return 0;
849
850 /* Read at the head location and check it is empty flash */
851 err = ubi_read(c->ubi, lnum, sbuf, offs, len);
Artem Bityutskiy431102f2009-06-29 18:58:34 +0300852 if (err || !is_empty(sbuf, len)) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300853 dbg_rcvry("cleaning head at %d:%d", lnum, offs);
854 if (offs == 0)
855 return ubifs_leb_unmap(c, lnum);
856 err = ubi_read(c->ubi, lnum, sbuf, 0, offs);
857 if (err)
858 return err;
859 return ubi_leb_change(c->ubi, lnum, sbuf, offs, UBI_UNKNOWN);
860 }
861
862 return 0;
863}
864
865/**
866 * ubifs_recover_inl_heads - recover index and LPT heads.
867 * @c: UBIFS file-system description object
868 * @sbuf: LEB-sized buffer to use
869 *
870 * This function ensures that there is no data on the flash at the index and
871 * LPT head locations.
872 *
873 * This deals with the recovery of a half-completed journal commit. UBIFS is
874 * careful never to overwrite the last version of the index or the LPT. Because
875 * the index and LPT are wandering trees, data from a half-completed commit will
876 * not be referenced anywhere in UBIFS. The data will be either in LEBs that are
877 * assumed to be empty and will be unmapped anyway before use, or in the index
878 * and LPT heads.
879 *
880 * This function returns %0 on success and a negative error code on failure.
881 */
882int ubifs_recover_inl_heads(const struct ubifs_info *c, void *sbuf)
883{
884 int err;
885
886 ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY) || c->remounting_rw);
887
888 dbg_rcvry("checking index head at %d:%d", c->ihead_lnum, c->ihead_offs);
889 err = recover_head(c, c->ihead_lnum, c->ihead_offs, sbuf);
890 if (err)
891 return err;
892
893 dbg_rcvry("checking LPT head at %d:%d", c->nhead_lnum, c->nhead_offs);
894 err = recover_head(c, c->nhead_lnum, c->nhead_offs, sbuf);
895 if (err)
896 return err;
897
898 return 0;
899}
900
901/**
902 * clean_an_unclean_leb - read and write a LEB to remove corruption.
903 * @c: UBIFS file-system description object
904 * @ucleb: unclean LEB information
905 * @sbuf: LEB-sized buffer to use
906 *
907 * This function reads a LEB up to a point pre-determined by the mount recovery,
908 * checks the nodes, and writes the result back to the flash, thereby cleaning
909 * off any following corruption, or non-fatal ECC errors.
910 *
911 * This function returns %0 on success and a negative error code on failure.
912 */
913static int clean_an_unclean_leb(const struct ubifs_info *c,
914 struct ubifs_unclean_leb *ucleb, void *sbuf)
915{
916 int err, lnum = ucleb->lnum, offs = 0, len = ucleb->endpt, quiet = 1;
917 void *buf = sbuf;
918
919 dbg_rcvry("LEB %d len %d", lnum, len);
920
921 if (len == 0) {
922 /* Nothing to read, just unmap it */
923 err = ubifs_leb_unmap(c, lnum);
924 if (err)
925 return err;
926 return 0;
927 }
928
929 err = ubi_read(c->ubi, lnum, buf, offs, len);
930 if (err && err != -EBADMSG)
931 return err;
932
933 while (len >= 8) {
934 int ret;
935
936 cond_resched();
937
938 /* Scan quietly until there is an error */
939 ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
940
941 if (ret == SCANNED_A_NODE) {
942 /* A valid node, and not a padding node */
943 struct ubifs_ch *ch = buf;
944 int node_len;
945
946 node_len = ALIGN(le32_to_cpu(ch->len), 8);
947 offs += node_len;
948 buf += node_len;
949 len -= node_len;
950 continue;
951 }
952
953 if (ret > 0) {
954 /* Padding bytes or a valid padding node */
955 offs += ret;
956 buf += ret;
957 len -= ret;
958 continue;
959 }
960
961 if (ret == SCANNED_EMPTY_SPACE) {
962 ubifs_err("unexpected empty space at %d:%d",
963 lnum, offs);
964 return -EUCLEAN;
965 }
966
967 if (quiet) {
968 /* Redo the last scan but noisily */
969 quiet = 0;
970 continue;
971 }
972
973 ubifs_scanned_corruption(c, lnum, offs, buf);
974 return -EUCLEAN;
975 }
976
977 /* Pad to min_io_size */
978 len = ALIGN(ucleb->endpt, c->min_io_size);
979 if (len > ucleb->endpt) {
980 int pad_len = len - ALIGN(ucleb->endpt, 8);
981
982 if (pad_len > 0) {
983 buf = c->sbuf + len - pad_len;
984 ubifs_pad(c, buf, pad_len);
985 }
986 }
987
988 /* Write back the LEB atomically */
989 err = ubi_leb_change(c->ubi, lnum, sbuf, len, UBI_UNKNOWN);
990 if (err)
991 return err;
992
993 dbg_rcvry("cleaned LEB %d", lnum);
994
995 return 0;
996}
997
998/**
999 * ubifs_clean_lebs - clean LEBs recovered during read-only mount.
1000 * @c: UBIFS file-system description object
1001 * @sbuf: LEB-sized buffer to use
1002 *
1003 * This function cleans a LEB identified during recovery that needs to be
1004 * written but was not because UBIFS was mounted read-only. This happens when
1005 * remounting to read-write mode.
1006 *
1007 * This function returns %0 on success and a negative error code on failure.
1008 */
1009int ubifs_clean_lebs(const struct ubifs_info *c, void *sbuf)
1010{
1011 dbg_rcvry("recovery");
1012 while (!list_empty(&c->unclean_leb_list)) {
1013 struct ubifs_unclean_leb *ucleb;
1014 int err;
1015
1016 ucleb = list_entry(c->unclean_leb_list.next,
1017 struct ubifs_unclean_leb, list);
1018 err = clean_an_unclean_leb(c, ucleb, sbuf);
1019 if (err)
1020 return err;
1021 list_del(&ucleb->list);
1022 kfree(ucleb);
1023 }
1024 return 0;
1025}
1026
1027/**
1028 * ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit.
1029 * @c: UBIFS file-system description object
1030 *
1031 * Out-of-place garbage collection requires always one empty LEB with which to
1032 * start garbage collection. The LEB number is recorded in c->gc_lnum and is
1033 * written to the master node on unmounting. In the case of an unclean unmount
1034 * the value of gc_lnum recorded in the master node is out of date and cannot
1035 * be used. Instead, recovery must allocate an empty LEB for this purpose.
1036 * However, there may not be enough empty space, in which case it must be
1037 * possible to GC the dirtiest LEB into the GC head LEB.
1038 *
1039 * This function also runs the commit which causes the TNC updates from
1040 * size-recovery and orphans to be written to the flash. That is important to
1041 * ensure correct replay order for subsequent mounts.
1042 *
1043 * This function returns %0 on success and a negative error code on failure.
1044 */
1045int ubifs_rcvry_gc_commit(struct ubifs_info *c)
1046{
1047 struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
1048 struct ubifs_lprops lp;
1049 int lnum, err;
1050
1051 c->gc_lnum = -1;
1052 if (wbuf->lnum == -1) {
1053 dbg_rcvry("no GC head LEB");
1054 goto find_free;
1055 }
1056 /*
1057 * See whether the used space in the dirtiest LEB fits in the GC head
1058 * LEB.
1059 */
1060 if (wbuf->offs == c->leb_size) {
1061 dbg_rcvry("no room in GC head LEB");
1062 goto find_free;
1063 }
1064 err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2);
1065 if (err) {
1066 if (err == -ENOSPC)
1067 dbg_err("could not find a dirty LEB");
1068 return err;
1069 }
1070 ubifs_assert(!(lp.flags & LPROPS_INDEX));
1071 lnum = lp.lnum;
1072 if (lp.free + lp.dirty == c->leb_size) {
1073 /* An empty LEB was returned */
1074 if (lp.free != c->leb_size) {
1075 err = ubifs_change_one_lp(c, lnum, c->leb_size,
1076 0, 0, 0, 0);
1077 if (err)
1078 return err;
1079 }
1080 err = ubifs_leb_unmap(c, lnum);
1081 if (err)
1082 return err;
1083 c->gc_lnum = lnum;
1084 dbg_rcvry("allocated LEB %d for GC", lnum);
1085 /* Run the commit */
1086 dbg_rcvry("committing");
1087 return ubifs_run_commit(c);
1088 }
1089 /*
1090 * There was no empty LEB so the used space in the dirtiest LEB must fit
1091 * in the GC head LEB.
1092 */
1093 if (lp.free + lp.dirty < wbuf->offs) {
1094 dbg_rcvry("LEB %d doesn't fit in GC head LEB %d:%d",
1095 lnum, wbuf->lnum, wbuf->offs);
1096 err = ubifs_return_leb(c, lnum);
1097 if (err)
1098 return err;
1099 goto find_free;
1100 }
1101 /*
1102 * We run the commit before garbage collection otherwise subsequent
1103 * mounts will see the GC and orphan deletion in a different order.
1104 */
1105 dbg_rcvry("committing");
1106 err = ubifs_run_commit(c);
1107 if (err)
1108 return err;
1109 /*
1110 * The data in the dirtiest LEB fits in the GC head LEB, so do the GC
1111 * - use locking to keep 'ubifs_assert()' happy.
1112 */
1113 dbg_rcvry("GC'ing LEB %d", lnum);
1114 mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
1115 err = ubifs_garbage_collect_leb(c, &lp);
1116 if (err >= 0) {
1117 int err2 = ubifs_wbuf_sync_nolock(wbuf);
1118
1119 if (err2)
1120 err = err2;
1121 }
1122 mutex_unlock(&wbuf->io_mutex);
1123 if (err < 0) {
1124 dbg_err("GC failed, error %d", err);
1125 if (err == -EAGAIN)
1126 err = -EINVAL;
1127 return err;
1128 }
1129 if (err != LEB_RETAINED) {
1130 dbg_err("GC returned %d", err);
1131 return -EINVAL;
1132 }
1133 err = ubifs_leb_unmap(c, c->gc_lnum);
1134 if (err)
1135 return err;
1136 dbg_rcvry("allocated LEB %d for GC", lnum);
1137 return 0;
1138
1139find_free:
1140 /*
1141 * There is no GC head LEB or the free space in the GC head LEB is too
1142 * small. Allocate gc_lnum by calling 'ubifs_find_free_leb_for_idx()' so
1143 * GC is not run.
1144 */
1145 lnum = ubifs_find_free_leb_for_idx(c);
1146 if (lnum < 0) {
1147 dbg_err("could not find an empty LEB");
1148 return lnum;
1149 }
1150 /* And reset the index flag */
1151 err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
1152 LPROPS_INDEX, 0);
1153 if (err)
1154 return err;
1155 c->gc_lnum = lnum;
1156 dbg_rcvry("allocated LEB %d for GC", lnum);
1157 /* Run the commit */
1158 dbg_rcvry("committing");
1159 return ubifs_run_commit(c);
1160}
1161
1162/**
1163 * struct size_entry - inode size information for recovery.
1164 * @rb: link in the RB-tree of sizes
1165 * @inum: inode number
1166 * @i_size: size on inode
1167 * @d_size: maximum size based on data nodes
1168 * @exists: indicates whether the inode exists
1169 * @inode: inode if pinned in memory awaiting rw mode to fix it
1170 */
1171struct size_entry {
1172 struct rb_node rb;
1173 ino_t inum;
1174 loff_t i_size;
1175 loff_t d_size;
1176 int exists;
1177 struct inode *inode;
1178};
1179
1180/**
1181 * add_ino - add an entry to the size tree.
1182 * @c: UBIFS file-system description object
1183 * @inum: inode number
1184 * @i_size: size on inode
1185 * @d_size: maximum size based on data nodes
1186 * @exists: indicates whether the inode exists
1187 */
1188static int add_ino(struct ubifs_info *c, ino_t inum, loff_t i_size,
1189 loff_t d_size, int exists)
1190{
1191 struct rb_node **p = &c->size_tree.rb_node, *parent = NULL;
1192 struct size_entry *e;
1193
1194 while (*p) {
1195 parent = *p;
1196 e = rb_entry(parent, struct size_entry, rb);
1197 if (inum < e->inum)
1198 p = &(*p)->rb_left;
1199 else
1200 p = &(*p)->rb_right;
1201 }
1202
1203 e = kzalloc(sizeof(struct size_entry), GFP_KERNEL);
1204 if (!e)
1205 return -ENOMEM;
1206
1207 e->inum = inum;
1208 e->i_size = i_size;
1209 e->d_size = d_size;
1210 e->exists = exists;
1211
1212 rb_link_node(&e->rb, parent, p);
1213 rb_insert_color(&e->rb, &c->size_tree);
1214
1215 return 0;
1216}
1217
1218/**
1219 * find_ino - find an entry on the size tree.
1220 * @c: UBIFS file-system description object
1221 * @inum: inode number
1222 */
1223static struct size_entry *find_ino(struct ubifs_info *c, ino_t inum)
1224{
1225 struct rb_node *p = c->size_tree.rb_node;
1226 struct size_entry *e;
1227
1228 while (p) {
1229 e = rb_entry(p, struct size_entry, rb);
1230 if (inum < e->inum)
1231 p = p->rb_left;
1232 else if (inum > e->inum)
1233 p = p->rb_right;
1234 else
1235 return e;
1236 }
1237 return NULL;
1238}
1239
1240/**
1241 * remove_ino - remove an entry from the size tree.
1242 * @c: UBIFS file-system description object
1243 * @inum: inode number
1244 */
1245static void remove_ino(struct ubifs_info *c, ino_t inum)
1246{
1247 struct size_entry *e = find_ino(c, inum);
1248
1249 if (!e)
1250 return;
1251 rb_erase(&e->rb, &c->size_tree);
1252 kfree(e);
1253}
1254
1255/**
1256 * ubifs_destroy_size_tree - free resources related to the size tree.
1257 * @c: UBIFS file-system description object
1258 */
1259void ubifs_destroy_size_tree(struct ubifs_info *c)
1260{
1261 struct rb_node *this = c->size_tree.rb_node;
1262 struct size_entry *e;
1263
1264 while (this) {
1265 if (this->rb_left) {
1266 this = this->rb_left;
1267 continue;
1268 } else if (this->rb_right) {
1269 this = this->rb_right;
1270 continue;
1271 }
1272 e = rb_entry(this, struct size_entry, rb);
1273 if (e->inode)
1274 iput(e->inode);
1275 this = rb_parent(this);
1276 if (this) {
1277 if (this->rb_left == &e->rb)
1278 this->rb_left = NULL;
1279 else
1280 this->rb_right = NULL;
1281 }
1282 kfree(e);
1283 }
1284 c->size_tree = RB_ROOT;
1285}
1286
1287/**
1288 * ubifs_recover_size_accum - accumulate inode sizes for recovery.
1289 * @c: UBIFS file-system description object
1290 * @key: node key
1291 * @deletion: node is for a deletion
1292 * @new_size: inode size
1293 *
1294 * This function has two purposes:
1295 * 1) to ensure there are no data nodes that fall outside the inode size
1296 * 2) to ensure there are no data nodes for inodes that do not exist
1297 * To accomplish those purposes, a rb-tree is constructed containing an entry
1298 * for each inode number in the journal that has not been deleted, and recording
1299 * the size from the inode node, the maximum size of any data node (also altered
1300 * by truncations) and a flag indicating a inode number for which no inode node
1301 * was present in the journal.
1302 *
1303 * Note that there is still the possibility that there are data nodes that have
1304 * been committed that are beyond the inode size, however the only way to find
1305 * them would be to scan the entire index. Alternatively, some provision could
1306 * be made to record the size of inodes at the start of commit, which would seem
1307 * very cumbersome for a scenario that is quite unlikely and the only negative
1308 * consequence of which is wasted space.
1309 *
1310 * This functions returns %0 on success and a negative error code on failure.
1311 */
1312int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key,
1313 int deletion, loff_t new_size)
1314{
1315 ino_t inum = key_inum(c, key);
1316 struct size_entry *e;
1317 int err;
1318
1319 switch (key_type(c, key)) {
1320 case UBIFS_INO_KEY:
1321 if (deletion)
1322 remove_ino(c, inum);
1323 else {
1324 e = find_ino(c, inum);
1325 if (e) {
1326 e->i_size = new_size;
1327 e->exists = 1;
1328 } else {
1329 err = add_ino(c, inum, new_size, 0, 1);
1330 if (err)
1331 return err;
1332 }
1333 }
1334 break;
1335 case UBIFS_DATA_KEY:
1336 e = find_ino(c, inum);
1337 if (e) {
1338 if (new_size > e->d_size)
1339 e->d_size = new_size;
1340 } else {
1341 err = add_ino(c, inum, 0, new_size, 0);
1342 if (err)
1343 return err;
1344 }
1345 break;
1346 case UBIFS_TRUN_KEY:
1347 e = find_ino(c, inum);
1348 if (e)
1349 e->d_size = new_size;
1350 break;
1351 }
1352 return 0;
1353}
1354
1355/**
1356 * fix_size_in_place - fix inode size in place on flash.
1357 * @c: UBIFS file-system description object
1358 * @e: inode size information for recovery
1359 */
1360static int fix_size_in_place(struct ubifs_info *c, struct size_entry *e)
1361{
1362 struct ubifs_ino_node *ino = c->sbuf;
1363 unsigned char *p;
1364 union ubifs_key key;
1365 int err, lnum, offs, len;
1366 loff_t i_size;
1367 uint32_t crc;
1368
1369 /* Locate the inode node LEB number and offset */
1370 ino_key_init(c, &key, e->inum);
1371 err = ubifs_tnc_locate(c, &key, ino, &lnum, &offs);
1372 if (err)
1373 goto out;
1374 /*
1375 * If the size recorded on the inode node is greater than the size that
1376 * was calculated from nodes in the journal then don't change the inode.
1377 */
1378 i_size = le64_to_cpu(ino->size);
1379 if (i_size >= e->d_size)
1380 return 0;
1381 /* Read the LEB */
1382 err = ubi_read(c->ubi, lnum, c->sbuf, 0, c->leb_size);
1383 if (err)
1384 goto out;
1385 /* Change the size field and recalculate the CRC */
1386 ino = c->sbuf + offs;
1387 ino->size = cpu_to_le64(e->d_size);
1388 len = le32_to_cpu(ino->ch.len);
1389 crc = crc32(UBIFS_CRC32_INIT, (void *)ino + 8, len - 8);
1390 ino->ch.crc = cpu_to_le32(crc);
1391 /* Work out where data in the LEB ends and free space begins */
1392 p = c->sbuf;
1393 len = c->leb_size - 1;
1394 while (p[len] == 0xff)
1395 len -= 1;
1396 len = ALIGN(len + 1, c->min_io_size);
1397 /* Atomically write the fixed LEB back again */
1398 err = ubi_leb_change(c->ubi, lnum, c->sbuf, len, UBI_UNKNOWN);
1399 if (err)
1400 goto out;
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001401 dbg_rcvry("inode %lu at %d:%d size %lld -> %lld ",
1402 (unsigned long)e->inum, lnum, offs, i_size, e->d_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001403 return 0;
1404
1405out:
1406 ubifs_warn("inode %lu failed to fix size %lld -> %lld error %d",
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001407 (unsigned long)e->inum, e->i_size, e->d_size, err);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001408 return err;
1409}
1410
1411/**
1412 * ubifs_recover_size - recover inode size.
1413 * @c: UBIFS file-system description object
1414 *
1415 * This function attempts to fix inode size discrepancies identified by the
1416 * 'ubifs_recover_size_accum()' function.
1417 *
1418 * This functions returns %0 on success and a negative error code on failure.
1419 */
1420int ubifs_recover_size(struct ubifs_info *c)
1421{
1422 struct rb_node *this = rb_first(&c->size_tree);
1423
1424 while (this) {
1425 struct size_entry *e;
1426 int err;
1427
1428 e = rb_entry(this, struct size_entry, rb);
1429 if (!e->exists) {
1430 union ubifs_key key;
1431
1432 ino_key_init(c, &key, e->inum);
1433 err = ubifs_tnc_lookup(c, &key, c->sbuf);
1434 if (err && err != -ENOENT)
1435 return err;
1436 if (err == -ENOENT) {
1437 /* Remove data nodes that have no inode */
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001438 dbg_rcvry("removing ino %lu",
1439 (unsigned long)e->inum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001440 err = ubifs_tnc_remove_ino(c, e->inum);
1441 if (err)
1442 return err;
1443 } else {
1444 struct ubifs_ino_node *ino = c->sbuf;
1445
1446 e->exists = 1;
1447 e->i_size = le64_to_cpu(ino->size);
1448 }
1449 }
1450 if (e->exists && e->i_size < e->d_size) {
1451 if (!e->inode && (c->vfs_sb->s_flags & MS_RDONLY)) {
1452 /* Fix the inode size and pin it in memory */
1453 struct inode *inode;
1454
1455 inode = ubifs_iget(c->vfs_sb, e->inum);
1456 if (IS_ERR(inode))
1457 return PTR_ERR(inode);
1458 if (inode->i_size < e->d_size) {
1459 dbg_rcvry("ino %lu size %lld -> %lld",
Artem Bityutskiye84461a2008-10-29 12:08:43 +02001460 (unsigned long)e->inum,
1461 e->d_size, inode->i_size);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001462 inode->i_size = e->d_size;
1463 ubifs_inode(inode)->ui_size = e->d_size;
1464 e->inode = inode;
1465 this = rb_next(this);
1466 continue;
1467 }
1468 iput(inode);
1469 } else {
1470 /* Fix the size in place */
1471 err = fix_size_in_place(c, e);
1472 if (err)
1473 return err;
1474 if (e->inode)
1475 iput(e->inode);
1476 }
1477 }
1478 this = rb_next(this);
1479 rb_erase(&e->rb, &c->size_tree);
1480 kfree(e);
1481 }
1482 return 0;
1483}