Commit | Line | Data |
---|---|---|
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 | ||
27 | /** | |
28 | * scan_for_master - search the valid master node. | |
29 | * @c: UBIFS file-system description object | |
30 | * | |
31 | * This function scans the master node LEBs and search for the latest master | |
32 | * node. Returns zero in case of success and a negative error code in case of | |
33 | * failure. | |
34 | */ | |
35 | static int scan_for_master(struct ubifs_info *c) | |
36 | { | |
37 | struct ubifs_scan_leb *sleb; | |
38 | struct ubifs_scan_node *snod; | |
39 | int lnum, offs = 0, nodes_cnt; | |
40 | ||
41 | lnum = UBIFS_MST_LNUM; | |
42 | ||
43 | sleb = ubifs_scan(c, lnum, 0, c->sbuf); | |
44 | if (IS_ERR(sleb)) | |
45 | return PTR_ERR(sleb); | |
46 | nodes_cnt = sleb->nodes_cnt; | |
47 | if (nodes_cnt > 0) { | |
48 | snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, | |
49 | list); | |
50 | if (snod->type != UBIFS_MST_NODE) | |
51 | goto out; | |
52 | memcpy(c->mst_node, snod->node, snod->len); | |
53 | offs = snod->offs; | |
54 | } | |
55 | ubifs_scan_destroy(sleb); | |
56 | ||
57 | lnum += 1; | |
58 | ||
59 | sleb = ubifs_scan(c, lnum, 0, c->sbuf); | |
60 | if (IS_ERR(sleb)) | |
61 | return PTR_ERR(sleb); | |
62 | if (sleb->nodes_cnt != nodes_cnt) | |
63 | goto out; | |
64 | if (!sleb->nodes_cnt) | |
65 | goto out; | |
66 | snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); | |
67 | if (snod->type != UBIFS_MST_NODE) | |
68 | goto out; | |
69 | if (snod->offs != offs) | |
70 | goto out; | |
71 | if (memcmp((void *)c->mst_node + UBIFS_CH_SZ, | |
72 | (void *)snod->node + UBIFS_CH_SZ, | |
73 | UBIFS_MST_NODE_SZ - UBIFS_CH_SZ)) | |
74 | goto out; | |
75 | c->mst_offs = offs; | |
76 | ubifs_scan_destroy(sleb); | |
77 | return 0; | |
78 | ||
79 | out: | |
80 | ubifs_scan_destroy(sleb); | |
81 | return -EINVAL; | |
82 | } | |
83 | ||
84 | /** | |
85 | * validate_master - validate master node. | |
86 | * @c: UBIFS file-system description object | |
87 | * | |
88 | * This function validates data which was read from master node. Returns zero | |
89 | * if the data is all right and %-EINVAL if not. | |
90 | */ | |
91 | static int validate_master(const struct ubifs_info *c) | |
92 | { | |
93 | long long main_sz; | |
94 | int err; | |
95 | ||
96 | if (c->max_sqnum >= SQNUM_WATERMARK) { | |
97 | err = 1; | |
98 | goto out; | |
99 | } | |
100 | ||
101 | if (c->cmt_no >= c->max_sqnum) { | |
102 | err = 2; | |
103 | goto out; | |
104 | } | |
105 | ||
106 | if (c->highest_inum >= INUM_WATERMARK) { | |
107 | err = 3; | |
108 | goto out; | |
109 | } | |
110 | ||
111 | if (c->lhead_lnum < UBIFS_LOG_LNUM || | |
112 | c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs || | |
113 | c->lhead_offs < 0 || c->lhead_offs >= c->leb_size || | |
114 | c->lhead_offs & (c->min_io_size - 1)) { | |
115 | err = 4; | |
116 | goto out; | |
117 | } | |
118 | ||
119 | if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first || | |
120 | c->zroot.offs >= c->leb_size || c->zroot.offs & 7) { | |
121 | err = 5; | |
122 | goto out; | |
123 | } | |
124 | ||
125 | if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len || | |
126 | c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) { | |
127 | err = 6; | |
128 | goto out; | |
129 | } | |
130 | ||
131 | if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) { | |
132 | err = 7; | |
133 | goto out; | |
134 | } | |
135 | ||
136 | if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first || | |
137 | c->ihead_offs % c->min_io_size || c->ihead_offs < 0 || | |
138 | c->ihead_offs > c->leb_size || c->ihead_offs & 7) { | |
139 | err = 8; | |
140 | goto out; | |
141 | } | |
142 | ||
143 | main_sz = (long long)c->main_lebs * c->leb_size; | |
144 | if (c->old_idx_sz & 7 || c->old_idx_sz >= main_sz) { | |
145 | err = 9; | |
146 | goto out; | |
147 | } | |
148 | ||
149 | if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last || | |
150 | c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) { | |
151 | err = 10; | |
152 | goto out; | |
153 | } | |
154 | ||
155 | if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last || | |
156 | c->nhead_offs < 0 || c->nhead_offs % c->min_io_size || | |
157 | c->nhead_offs > c->leb_size) { | |
158 | err = 11; | |
159 | goto out; | |
160 | } | |
161 | ||
162 | if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last || | |
163 | c->ltab_offs < 0 || | |
164 | c->ltab_offs + c->ltab_sz > c->leb_size) { | |
165 | err = 12; | |
166 | goto out; | |
167 | } | |
168 | ||
169 | if (c->big_lpt && (c->lsave_lnum < c->lpt_first || | |
170 | c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 || | |
171 | c->lsave_offs + c->lsave_sz > c->leb_size)) { | |
172 | err = 13; | |
173 | goto out; | |
174 | } | |
175 | ||
176 | if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) { | |
177 | err = 14; | |
178 | goto out; | |
179 | } | |
180 | ||
181 | if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) { | |
182 | err = 15; | |
183 | goto out; | |
184 | } | |
185 | ||
186 | if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) { | |
187 | err = 16; | |
188 | goto out; | |
189 | } | |
190 | ||
191 | if (c->lst.total_free < 0 || c->lst.total_free > main_sz || | |
192 | c->lst.total_free & 7) { | |
193 | err = 17; | |
194 | goto out; | |
195 | } | |
196 | ||
197 | if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) { | |
198 | err = 18; | |
199 | goto out; | |
200 | } | |
201 | ||
202 | if (c->lst.total_used < 0 || (c->lst.total_used & 7)) { | |
203 | err = 19; | |
204 | goto out; | |
205 | } | |
206 | ||
207 | if (c->lst.total_free + c->lst.total_dirty + | |
208 | c->lst.total_used > main_sz) { | |
209 | err = 20; | |
210 | goto out; | |
211 | } | |
212 | ||
213 | if (c->lst.total_dead + c->lst.total_dark + | |
214 | c->lst.total_used + c->old_idx_sz > main_sz) { | |
215 | err = 21; | |
216 | goto out; | |
217 | } | |
218 | ||
219 | if (c->lst.total_dead < 0 || | |
220 | c->lst.total_dead > c->lst.total_free + c->lst.total_dirty || | |
221 | c->lst.total_dead & 7) { | |
222 | err = 22; | |
223 | goto out; | |
224 | } | |
225 | ||
226 | if (c->lst.total_dark < 0 || | |
227 | c->lst.total_dark > c->lst.total_free + c->lst.total_dirty || | |
228 | c->lst.total_dark & 7) { | |
229 | err = 23; | |
230 | goto out; | |
231 | } | |
232 | ||
233 | return 0; | |
234 | ||
235 | out: | |
236 | ubifs_err("bad master node at offset %d error %d", c->mst_offs, err); | |
237 | dbg_dump_node(c, c->mst_node); | |
238 | return -EINVAL; | |
239 | } | |
240 | ||
241 | /** | |
242 | * ubifs_read_master - read master node. | |
243 | * @c: UBIFS file-system description object | |
244 | * | |
245 | * This function finds and reads the master node during file-system mount. If | |
246 | * the flash is empty, it creates default master node as well. Returns zero in | |
247 | * case of success and a negative error code in case of failure. | |
248 | */ | |
249 | int ubifs_read_master(struct ubifs_info *c) | |
250 | { | |
251 | int err, old_leb_cnt; | |
252 | ||
253 | c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL); | |
254 | if (!c->mst_node) | |
255 | return -ENOMEM; | |
256 | ||
257 | err = scan_for_master(c); | |
258 | if (err) { | |
259 | err = ubifs_recover_master_node(c); | |
260 | if (err) | |
261 | /* | |
262 | * Note, we do not free 'c->mst_node' here because the | |
263 | * unmount routine will take care of this. | |
264 | */ | |
265 | return err; | |
266 | } | |
267 | ||
268 | /* Make sure that the recovery flag is clear */ | |
269 | c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY); | |
270 | ||
271 | c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum); | |
272 | c->highest_inum = le64_to_cpu(c->mst_node->highest_inum); | |
273 | c->cmt_no = le64_to_cpu(c->mst_node->cmt_no); | |
274 | c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum); | |
275 | c->zroot.offs = le32_to_cpu(c->mst_node->root_offs); | |
276 | c->zroot.len = le32_to_cpu(c->mst_node->root_len); | |
277 | c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum); | |
278 | c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum); | |
279 | c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum); | |
280 | c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs); | |
281 | c->old_idx_sz = le64_to_cpu(c->mst_node->index_size); | |
282 | c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum); | |
283 | c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs); | |
284 | c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum); | |
285 | c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs); | |
286 | c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum); | |
287 | c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs); | |
288 | c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum); | |
289 | c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs); | |
290 | c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum); | |
291 | c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs); | |
292 | c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs); | |
293 | old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt); | |
294 | c->lst.total_free = le64_to_cpu(c->mst_node->total_free); | |
295 | c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty); | |
296 | c->lst.total_used = le64_to_cpu(c->mst_node->total_used); | |
297 | c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead); | |
298 | c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark); | |
299 | ||
300 | c->calc_idx_sz = c->old_idx_sz; | |
301 | ||
302 | if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS)) | |
303 | c->no_orphs = 1; | |
304 | ||
305 | if (old_leb_cnt != c->leb_cnt) { | |
306 | /* The file system has been resized */ | |
307 | int growth = c->leb_cnt - old_leb_cnt; | |
308 | ||
309 | if (c->leb_cnt < old_leb_cnt || | |
310 | c->leb_cnt < UBIFS_MIN_LEB_CNT) { | |
311 | ubifs_err("bad leb_cnt on master node"); | |
312 | dbg_dump_node(c, c->mst_node); | |
313 | return -EINVAL; | |
314 | } | |
315 | ||
316 | dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs", | |
317 | old_leb_cnt, c->leb_cnt); | |
318 | c->lst.empty_lebs += growth; | |
319 | c->lst.total_free += growth * (long long)c->leb_size; | |
320 | c->lst.total_dark += growth * (long long)c->dark_wm; | |
321 | ||
322 | /* | |
323 | * Reflect changes back onto the master node. N.B. the master | |
324 | * node gets written immediately whenever mounting (or | |
325 | * remounting) in read-write mode, so we do not need to write it | |
326 | * here. | |
327 | */ | |
328 | c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt); | |
329 | c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs); | |
330 | c->mst_node->total_free = cpu_to_le64(c->lst.total_free); | |
331 | c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark); | |
332 | } | |
333 | ||
334 | err = validate_master(c); | |
335 | if (err) | |
336 | return err; | |
337 | ||
338 | err = dbg_old_index_check_init(c, &c->zroot); | |
339 | ||
340 | return err; | |
341 | } | |
342 | ||
343 | /** | |
344 | * ubifs_write_master - write master node. | |
345 | * @c: UBIFS file-system description object | |
346 | * | |
347 | * This function writes the master node. The caller has to take the | |
348 | * @c->mst_mutex lock before calling this function. Returns zero in case of | |
349 | * success and a negative error code in case of failure. The master node is | |
350 | * written twice to enable recovery. | |
351 | */ | |
352 | int ubifs_write_master(struct ubifs_info *c) | |
353 | { | |
354 | int err, lnum, offs, len; | |
355 | ||
356 | if (c->ro_media) | |
357 | return -EINVAL; | |
358 | ||
359 | lnum = UBIFS_MST_LNUM; | |
360 | offs = c->mst_offs + c->mst_node_alsz; | |
361 | len = UBIFS_MST_NODE_SZ; | |
362 | ||
363 | if (offs + UBIFS_MST_NODE_SZ > c->leb_size) { | |
364 | err = ubifs_leb_unmap(c, lnum); | |
365 | if (err) | |
366 | return err; | |
367 | offs = 0; | |
368 | } | |
369 | ||
370 | c->mst_offs = offs; | |
371 | c->mst_node->highest_inum = cpu_to_le64(c->highest_inum); | |
372 | ||
373 | err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM); | |
374 | if (err) | |
375 | return err; | |
376 | ||
377 | lnum += 1; | |
378 | ||
379 | if (offs == 0) { | |
380 | err = ubifs_leb_unmap(c, lnum); | |
381 | if (err) | |
382 | return err; | |
383 | } | |
384 | err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM); | |
385 | ||
386 | return err; | |
387 | } |