Commit | Line | Data |
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1e51764a AB |
1 | /* |
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: Artem Bityutskiy (Битюцкий Артём) | |
20 | * Adrian Hunter | |
21 | */ | |
22 | ||
23 | /* This file implements reading and writing the master node */ | |
24 | ||
25 | #include "ubifs.h" | |
26 | ||
625700cc SH |
27 | /** |
28 | * ubifs_compare_master_node - compare two UBIFS master nodes | |
29 | * @c: UBIFS file-system description object | |
30 | * @m1: the first node | |
31 | * @m2: the second node | |
32 | * | |
33 | * This function compares two UBIFS master nodes. Returns 0 if they are equal | |
34 | * and nonzero if not. | |
35 | */ | |
36 | int ubifs_compare_master_node(struct ubifs_info *c, void *m1, void *m2) | |
37 | { | |
38 | int ret; | |
39 | int behind; | |
40 | int hmac_offs = offsetof(struct ubifs_mst_node, hmac); | |
41 | ||
42 | /* | |
43 | * Do not compare the common node header since the sequence number and | |
44 | * hence the CRC are different. | |
45 | */ | |
46 | ret = memcmp(m1 + UBIFS_CH_SZ, m2 + UBIFS_CH_SZ, | |
47 | hmac_offs - UBIFS_CH_SZ); | |
48 | if (ret) | |
49 | return ret; | |
50 | ||
51 | /* | |
52 | * Do not compare the embedded HMAC aswell which also must be different | |
53 | * due to the different common node header. | |
54 | */ | |
55 | behind = hmac_offs + UBIFS_MAX_HMAC_LEN; | |
56 | ||
57 | if (UBIFS_MST_NODE_SZ > behind) | |
58 | return memcmp(m1 + behind, m2 + behind, UBIFS_MST_NODE_SZ - behind); | |
59 | ||
60 | return 0; | |
61 | } | |
62 | ||
1e51764a AB |
63 | /** |
64 | * scan_for_master - search the valid master node. | |
65 | * @c: UBIFS file-system description object | |
66 | * | |
67 | * This function scans the master node LEBs and search for the latest master | |
0dcd18e4 AB |
68 | * node. Returns zero in case of success, %-EUCLEAN if there master area is |
69 | * corrupted and requires recovery, and a negative error code in case of | |
1e51764a AB |
70 | * failure. |
71 | */ | |
72 | static int scan_for_master(struct ubifs_info *c) | |
73 | { | |
74 | struct ubifs_scan_leb *sleb; | |
75 | struct ubifs_scan_node *snod; | |
625700cc | 76 | int lnum, offs = 0, nodes_cnt, err; |
1e51764a AB |
77 | |
78 | lnum = UBIFS_MST_LNUM; | |
79 | ||
348709ba | 80 | sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); |
1e51764a AB |
81 | if (IS_ERR(sleb)) |
82 | return PTR_ERR(sleb); | |
83 | nodes_cnt = sleb->nodes_cnt; | |
84 | if (nodes_cnt > 0) { | |
85 | snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, | |
86 | list); | |
87 | if (snod->type != UBIFS_MST_NODE) | |
0dcd18e4 | 88 | goto out_dump; |
1e51764a AB |
89 | memcpy(c->mst_node, snod->node, snod->len); |
90 | offs = snod->offs; | |
91 | } | |
92 | ubifs_scan_destroy(sleb); | |
93 | ||
94 | lnum += 1; | |
95 | ||
348709ba | 96 | sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); |
1e51764a AB |
97 | if (IS_ERR(sleb)) |
98 | return PTR_ERR(sleb); | |
99 | if (sleb->nodes_cnt != nodes_cnt) | |
100 | goto out; | |
101 | if (!sleb->nodes_cnt) | |
102 | goto out; | |
103 | snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); | |
104 | if (snod->type != UBIFS_MST_NODE) | |
0dcd18e4 | 105 | goto out_dump; |
1e51764a AB |
106 | if (snod->offs != offs) |
107 | goto out; | |
625700cc | 108 | if (ubifs_compare_master_node(c, c->mst_node, snod->node)) |
1e51764a | 109 | goto out; |
625700cc | 110 | |
1e51764a AB |
111 | c->mst_offs = offs; |
112 | ubifs_scan_destroy(sleb); | |
625700cc SH |
113 | |
114 | if (!ubifs_authenticated(c)) | |
115 | return 0; | |
116 | ||
117 | err = ubifs_node_verify_hmac(c, c->mst_node, | |
118 | sizeof(struct ubifs_mst_node), | |
119 | offsetof(struct ubifs_mst_node, hmac)); | |
120 | if (err) { | |
121 | ubifs_err(c, "Failed to verify master node HMAC"); | |
122 | return -EPERM; | |
123 | } | |
124 | ||
1e51764a AB |
125 | return 0; |
126 | ||
127 | out: | |
128 | ubifs_scan_destroy(sleb); | |
0dcd18e4 AB |
129 | return -EUCLEAN; |
130 | ||
131 | out_dump: | |
235c362b | 132 | ubifs_err(c, "unexpected node type %d master LEB %d:%d", |
0dcd18e4 AB |
133 | snod->type, lnum, snod->offs); |
134 | ubifs_scan_destroy(sleb); | |
1e51764a AB |
135 | return -EINVAL; |
136 | } | |
137 | ||
138 | /** | |
139 | * validate_master - validate master node. | |
140 | * @c: UBIFS file-system description object | |
141 | * | |
142 | * This function validates data which was read from master node. Returns zero | |
143 | * if the data is all right and %-EINVAL if not. | |
144 | */ | |
145 | static int validate_master(const struct ubifs_info *c) | |
146 | { | |
147 | long long main_sz; | |
148 | int err; | |
149 | ||
150 | if (c->max_sqnum >= SQNUM_WATERMARK) { | |
151 | err = 1; | |
152 | goto out; | |
153 | } | |
154 | ||
155 | if (c->cmt_no >= c->max_sqnum) { | |
156 | err = 2; | |
157 | goto out; | |
158 | } | |
159 | ||
160 | if (c->highest_inum >= INUM_WATERMARK) { | |
161 | err = 3; | |
162 | goto out; | |
163 | } | |
164 | ||
165 | if (c->lhead_lnum < UBIFS_LOG_LNUM || | |
166 | c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs || | |
167 | c->lhead_offs < 0 || c->lhead_offs >= c->leb_size || | |
168 | c->lhead_offs & (c->min_io_size - 1)) { | |
169 | err = 4; | |
170 | goto out; | |
171 | } | |
172 | ||
173 | if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first || | |
174 | c->zroot.offs >= c->leb_size || c->zroot.offs & 7) { | |
175 | err = 5; | |
176 | goto out; | |
177 | } | |
178 | ||
179 | if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len || | |
180 | c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) { | |
181 | err = 6; | |
182 | goto out; | |
183 | } | |
184 | ||
185 | if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) { | |
186 | err = 7; | |
187 | goto out; | |
188 | } | |
189 | ||
190 | if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first || | |
191 | c->ihead_offs % c->min_io_size || c->ihead_offs < 0 || | |
192 | c->ihead_offs > c->leb_size || c->ihead_offs & 7) { | |
193 | err = 8; | |
194 | goto out; | |
195 | } | |
196 | ||
197 | main_sz = (long long)c->main_lebs * c->leb_size; | |
b137545c | 198 | if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) { |
1e51764a AB |
199 | err = 9; |
200 | goto out; | |
201 | } | |
202 | ||
203 | if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last || | |
204 | c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) { | |
205 | err = 10; | |
206 | goto out; | |
207 | } | |
208 | ||
209 | if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last || | |
210 | c->nhead_offs < 0 || c->nhead_offs % c->min_io_size || | |
211 | c->nhead_offs > c->leb_size) { | |
212 | err = 11; | |
213 | goto out; | |
214 | } | |
215 | ||
216 | if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last || | |
217 | c->ltab_offs < 0 || | |
218 | c->ltab_offs + c->ltab_sz > c->leb_size) { | |
219 | err = 12; | |
220 | goto out; | |
221 | } | |
222 | ||
223 | if (c->big_lpt && (c->lsave_lnum < c->lpt_first || | |
224 | c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 || | |
225 | c->lsave_offs + c->lsave_sz > c->leb_size)) { | |
226 | err = 13; | |
227 | goto out; | |
228 | } | |
229 | ||
230 | if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) { | |
231 | err = 14; | |
232 | goto out; | |
233 | } | |
234 | ||
235 | if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) { | |
236 | err = 15; | |
237 | goto out; | |
238 | } | |
239 | ||
240 | if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) { | |
241 | err = 16; | |
242 | goto out; | |
243 | } | |
244 | ||
245 | if (c->lst.total_free < 0 || c->lst.total_free > main_sz || | |
246 | c->lst.total_free & 7) { | |
247 | err = 17; | |
248 | goto out; | |
249 | } | |
250 | ||
251 | if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) { | |
252 | err = 18; | |
253 | goto out; | |
254 | } | |
255 | ||
256 | if (c->lst.total_used < 0 || (c->lst.total_used & 7)) { | |
257 | err = 19; | |
258 | goto out; | |
259 | } | |
260 | ||
261 | if (c->lst.total_free + c->lst.total_dirty + | |
262 | c->lst.total_used > main_sz) { | |
263 | err = 20; | |
264 | goto out; | |
265 | } | |
266 | ||
267 | if (c->lst.total_dead + c->lst.total_dark + | |
b137545c | 268 | c->lst.total_used + c->bi.old_idx_sz > main_sz) { |
1e51764a AB |
269 | err = 21; |
270 | goto out; | |
271 | } | |
272 | ||
273 | if (c->lst.total_dead < 0 || | |
274 | c->lst.total_dead > c->lst.total_free + c->lst.total_dirty || | |
275 | c->lst.total_dead & 7) { | |
276 | err = 22; | |
277 | goto out; | |
278 | } | |
279 | ||
280 | if (c->lst.total_dark < 0 || | |
281 | c->lst.total_dark > c->lst.total_free + c->lst.total_dirty || | |
282 | c->lst.total_dark & 7) { | |
283 | err = 23; | |
284 | goto out; | |
285 | } | |
286 | ||
287 | return 0; | |
288 | ||
289 | out: | |
235c362b | 290 | ubifs_err(c, "bad master node at offset %d error %d", c->mst_offs, err); |
edf6be24 | 291 | ubifs_dump_node(c, c->mst_node); |
1e51764a AB |
292 | return -EINVAL; |
293 | } | |
294 | ||
295 | /** | |
296 | * ubifs_read_master - read master node. | |
297 | * @c: UBIFS file-system description object | |
298 | * | |
299 | * This function finds and reads the master node during file-system mount. If | |
300 | * the flash is empty, it creates default master node as well. Returns zero in | |
301 | * case of success and a negative error code in case of failure. | |
302 | */ | |
303 | int ubifs_read_master(struct ubifs_info *c) | |
304 | { | |
305 | int err, old_leb_cnt; | |
306 | ||
307 | c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL); | |
308 | if (!c->mst_node) | |
309 | return -ENOMEM; | |
310 | ||
311 | err = scan_for_master(c); | |
312 | if (err) { | |
0dcd18e4 AB |
313 | if (err == -EUCLEAN) |
314 | err = ubifs_recover_master_node(c); | |
1e51764a AB |
315 | if (err) |
316 | /* | |
317 | * Note, we do not free 'c->mst_node' here because the | |
318 | * unmount routine will take care of this. | |
319 | */ | |
320 | return err; | |
321 | } | |
322 | ||
323 | /* Make sure that the recovery flag is clear */ | |
324 | c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY); | |
325 | ||
326 | c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum); | |
327 | c->highest_inum = le64_to_cpu(c->mst_node->highest_inum); | |
328 | c->cmt_no = le64_to_cpu(c->mst_node->cmt_no); | |
329 | c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum); | |
330 | c->zroot.offs = le32_to_cpu(c->mst_node->root_offs); | |
331 | c->zroot.len = le32_to_cpu(c->mst_node->root_len); | |
332 | c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum); | |
333 | c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum); | |
334 | c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum); | |
335 | c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs); | |
b137545c | 336 | c->bi.old_idx_sz = le64_to_cpu(c->mst_node->index_size); |
1e51764a AB |
337 | c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum); |
338 | c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs); | |
339 | c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum); | |
340 | c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs); | |
341 | c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum); | |
342 | c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs); | |
343 | c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum); | |
344 | c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs); | |
345 | c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum); | |
346 | c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs); | |
347 | c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs); | |
348 | old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt); | |
349 | c->lst.total_free = le64_to_cpu(c->mst_node->total_free); | |
350 | c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty); | |
351 | c->lst.total_used = le64_to_cpu(c->mst_node->total_used); | |
352 | c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead); | |
353 | c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark); | |
354 | ||
16a26b20 SH |
355 | ubifs_copy_hash(c, c->mst_node->hash_root_idx, c->zroot.hash); |
356 | ||
b137545c | 357 | c->calc_idx_sz = c->bi.old_idx_sz; |
1e51764a AB |
358 | |
359 | if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS)) | |
360 | c->no_orphs = 1; | |
361 | ||
362 | if (old_leb_cnt != c->leb_cnt) { | |
363 | /* The file system has been resized */ | |
364 | int growth = c->leb_cnt - old_leb_cnt; | |
365 | ||
366 | if (c->leb_cnt < old_leb_cnt || | |
367 | c->leb_cnt < UBIFS_MIN_LEB_CNT) { | |
235c362b | 368 | ubifs_err(c, "bad leb_cnt on master node"); |
edf6be24 | 369 | ubifs_dump_node(c, c->mst_node); |
1e51764a AB |
370 | return -EINVAL; |
371 | } | |
372 | ||
373 | dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs", | |
374 | old_leb_cnt, c->leb_cnt); | |
375 | c->lst.empty_lebs += growth; | |
376 | c->lst.total_free += growth * (long long)c->leb_size; | |
377 | c->lst.total_dark += growth * (long long)c->dark_wm; | |
378 | ||
379 | /* | |
380 | * Reflect changes back onto the master node. N.B. the master | |
381 | * node gets written immediately whenever mounting (or | |
382 | * remounting) in read-write mode, so we do not need to write it | |
383 | * here. | |
384 | */ | |
385 | c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt); | |
386 | c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs); | |
387 | c->mst_node->total_free = cpu_to_le64(c->lst.total_free); | |
388 | c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark); | |
389 | } | |
390 | ||
391 | err = validate_master(c); | |
392 | if (err) | |
393 | return err; | |
394 | ||
395 | err = dbg_old_index_check_init(c, &c->zroot); | |
396 | ||
397 | return err; | |
398 | } | |
399 | ||
400 | /** | |
401 | * ubifs_write_master - write master node. | |
402 | * @c: UBIFS file-system description object | |
403 | * | |
07e19dff AB |
404 | * This function writes the master node. Returns zero in case of success and a |
405 | * negative error code in case of failure. The master node is written twice to | |
406 | * enable recovery. | |
1e51764a AB |
407 | */ |
408 | int ubifs_write_master(struct ubifs_info *c) | |
409 | { | |
410 | int err, lnum, offs, len; | |
411 | ||
6eb61d58 | 412 | ubifs_assert(c, !c->ro_media && !c->ro_mount); |
2680d722 | 413 | if (c->ro_error) |
a2b9df3f | 414 | return -EROFS; |
1e51764a AB |
415 | |
416 | lnum = UBIFS_MST_LNUM; | |
417 | offs = c->mst_offs + c->mst_node_alsz; | |
418 | len = UBIFS_MST_NODE_SZ; | |
419 | ||
420 | if (offs + UBIFS_MST_NODE_SZ > c->leb_size) { | |
421 | err = ubifs_leb_unmap(c, lnum); | |
422 | if (err) | |
423 | return err; | |
424 | offs = 0; | |
425 | } | |
426 | ||
427 | c->mst_offs = offs; | |
428 | c->mst_node->highest_inum = cpu_to_le64(c->highest_inum); | |
429 | ||
16a26b20 | 430 | ubifs_copy_hash(c, c->zroot.hash, c->mst_node->hash_root_idx); |
625700cc SH |
431 | err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs, |
432 | offsetof(struct ubifs_mst_node, hmac)); | |
1e51764a AB |
433 | if (err) |
434 | return err; | |
435 | ||
436 | lnum += 1; | |
437 | ||
438 | if (offs == 0) { | |
439 | err = ubifs_leb_unmap(c, lnum); | |
440 | if (err) | |
441 | return err; | |
442 | } | |
625700cc SH |
443 | err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs, |
444 | offsetof(struct ubifs_mst_node, hmac)); | |
1e51764a AB |
445 | |
446 | return err; | |
447 | } |