diff options
Diffstat (limited to 'fs/ubifs/master.c')
-rw-r--r-- | fs/ubifs/master.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c new file mode 100644 index 000000000000..71d5493bf565 --- /dev/null +++ b/fs/ubifs/master.c | |||
@@ -0,0 +1,387 @@ | |||
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 | } | ||