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 | /* | |
24 | * This file implements UBIFS superblock. The superblock is stored at the first | |
25 | * LEB of the volume and is never changed by UBIFS. Only user-space tools may | |
26 | * change it. The superblock node mostly contains geometry information. | |
27 | */ | |
28 | ||
29 | #include "ubifs.h" | |
30 | #include <linux/random.h> | |
4d61db4f | 31 | #include <linux/math64.h> |
1e51764a AB |
32 | |
33 | /* | |
34 | * Default journal size in logical eraseblocks as a percent of total | |
35 | * flash size. | |
36 | */ | |
37 | #define DEFAULT_JNL_PERCENT 5 | |
38 | ||
39 | /* Default maximum journal size in bytes */ | |
40 | #define DEFAULT_MAX_JNL (32*1024*1024) | |
41 | ||
42 | /* Default indexing tree fanout */ | |
43 | #define DEFAULT_FANOUT 8 | |
44 | ||
45 | /* Default number of data journal heads */ | |
46 | #define DEFAULT_JHEADS_CNT 1 | |
47 | ||
48 | /* Default positions of different LEBs in the main area */ | |
49 | #define DEFAULT_IDX_LEB 0 | |
50 | #define DEFAULT_DATA_LEB 1 | |
51 | #define DEFAULT_GC_LEB 2 | |
52 | ||
53 | /* Default number of LEB numbers in LPT's save table */ | |
54 | #define DEFAULT_LSAVE_CNT 256 | |
55 | ||
56 | /* Default reserved pool size as a percent of maximum free space */ | |
57 | #define DEFAULT_RP_PERCENT 5 | |
58 | ||
59 | /* The default maximum size of reserved pool in bytes */ | |
60 | #define DEFAULT_MAX_RP_SIZE (5*1024*1024) | |
61 | ||
62 | /* Default time granularity in nanoseconds */ | |
63 | #define DEFAULT_TIME_GRAN 1000000000 | |
64 | ||
65 | /** | |
66 | * create_default_filesystem - format empty UBI volume. | |
67 | * @c: UBIFS file-system description object | |
68 | * | |
69 | * This function creates default empty file-system. Returns zero in case of | |
70 | * success and a negative error code in case of failure. | |
71 | */ | |
72 | static int create_default_filesystem(struct ubifs_info *c) | |
73 | { | |
74 | struct ubifs_sb_node *sup; | |
75 | struct ubifs_mst_node *mst; | |
76 | struct ubifs_idx_node *idx; | |
77 | struct ubifs_branch *br; | |
78 | struct ubifs_ino_node *ino; | |
79 | struct ubifs_cs_node *cs; | |
80 | union ubifs_key key; | |
81 | int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; | |
82 | int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; | |
83 | int min_leb_cnt = UBIFS_MIN_LEB_CNT; | |
4d61db4f | 84 | long long tmp64, main_bytes; |
0ecb9529 | 85 | __le64 tmp_le64; |
1e51764a AB |
86 | |
87 | /* Some functions called from here depend on the @c->key_len filed */ | |
88 | c->key_len = UBIFS_SK_LEN; | |
89 | ||
90 | /* | |
91 | * First of all, we have to calculate default file-system geometry - | |
92 | * log size, journal size, etc. | |
93 | */ | |
94 | if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) | |
95 | /* We can first multiply then divide and have no overflow */ | |
96 | jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; | |
97 | else | |
98 | jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; | |
99 | ||
100 | if (jnl_lebs < UBIFS_MIN_JNL_LEBS) | |
101 | jnl_lebs = UBIFS_MIN_JNL_LEBS; | |
102 | if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) | |
103 | jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; | |
104 | ||
105 | /* | |
106 | * The log should be large enough to fit reference nodes for all bud | |
107 | * LEBs. Because buds do not have to start from the beginning of LEBs | |
108 | * (half of the LEB may contain committed data), the log should | |
109 | * generally be larger, make it twice as large. | |
110 | */ | |
111 | tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; | |
112 | log_lebs = tmp / c->leb_size; | |
113 | /* Plus one LEB reserved for commit */ | |
114 | log_lebs += 1; | |
115 | if (c->leb_cnt - min_leb_cnt > 8) { | |
116 | /* And some extra space to allow writes while committing */ | |
117 | log_lebs += 1; | |
118 | min_leb_cnt += 1; | |
119 | } | |
120 | ||
121 | max_buds = jnl_lebs - log_lebs; | |
122 | if (max_buds < UBIFS_MIN_BUD_LEBS) | |
123 | max_buds = UBIFS_MIN_BUD_LEBS; | |
124 | ||
125 | /* | |
126 | * Orphan nodes are stored in a separate area. One node can store a lot | |
127 | * of orphan inode numbers, but when new orphan comes we just add a new | |
128 | * orphan node. At some point the nodes are consolidated into one | |
129 | * orphan node. | |
130 | */ | |
131 | orph_lebs = UBIFS_MIN_ORPH_LEBS; | |
132 | #ifdef CONFIG_UBIFS_FS_DEBUG | |
133 | if (c->leb_cnt - min_leb_cnt > 1) | |
134 | /* | |
135 | * For debugging purposes it is better to have at least 2 | |
136 | * orphan LEBs, because the orphan subsystem would need to do | |
137 | * consolidations and would be stressed more. | |
138 | */ | |
139 | orph_lebs += 1; | |
140 | #endif | |
141 | ||
142 | main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; | |
143 | main_lebs -= orph_lebs; | |
144 | ||
145 | lpt_first = UBIFS_LOG_LNUM + log_lebs; | |
146 | c->lsave_cnt = DEFAULT_LSAVE_CNT; | |
147 | c->max_leb_cnt = c->leb_cnt; | |
148 | err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, | |
149 | &big_lpt); | |
150 | if (err) | |
151 | return err; | |
152 | ||
153 | dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, | |
154 | lpt_first + lpt_lebs - 1); | |
155 | ||
156 | main_first = c->leb_cnt - main_lebs; | |
157 | ||
158 | /* Create default superblock */ | |
159 | tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); | |
160 | sup = kzalloc(tmp, GFP_KERNEL); | |
161 | if (!sup) | |
162 | return -ENOMEM; | |
163 | ||
4d61db4f | 164 | tmp64 = (long long)max_buds * c->leb_size; |
1e51764a AB |
165 | if (big_lpt) |
166 | sup_flags |= UBIFS_FLG_BIGLPT; | |
167 | ||
168 | sup->ch.node_type = UBIFS_SB_NODE; | |
169 | sup->key_hash = UBIFS_KEY_HASH_R5; | |
170 | sup->flags = cpu_to_le32(sup_flags); | |
171 | sup->min_io_size = cpu_to_le32(c->min_io_size); | |
172 | sup->leb_size = cpu_to_le32(c->leb_size); | |
173 | sup->leb_cnt = cpu_to_le32(c->leb_cnt); | |
174 | sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); | |
175 | sup->max_bud_bytes = cpu_to_le64(tmp64); | |
176 | sup->log_lebs = cpu_to_le32(log_lebs); | |
177 | sup->lpt_lebs = cpu_to_le32(lpt_lebs); | |
178 | sup->orph_lebs = cpu_to_le32(orph_lebs); | |
179 | sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); | |
180 | sup->fanout = cpu_to_le32(DEFAULT_FANOUT); | |
181 | sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); | |
182 | sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION); | |
1e51764a | 183 | sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); |
553dea4d AB |
184 | if (c->mount_opts.override_compr) |
185 | sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); | |
186 | else | |
187 | sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO); | |
1e51764a AB |
188 | |
189 | generate_random_uuid(sup->uuid); | |
190 | ||
4d61db4f AB |
191 | main_bytes = (long long)main_lebs * c->leb_size; |
192 | tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); | |
1e51764a AB |
193 | if (tmp64 > DEFAULT_MAX_RP_SIZE) |
194 | tmp64 = DEFAULT_MAX_RP_SIZE; | |
195 | sup->rp_size = cpu_to_le64(tmp64); | |
963f0cf6 | 196 | sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); |
1e51764a AB |
197 | |
198 | err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM); | |
199 | kfree(sup); | |
200 | if (err) | |
201 | return err; | |
202 | ||
203 | dbg_gen("default superblock created at LEB 0:0"); | |
204 | ||
205 | /* Create default master node */ | |
206 | mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); | |
207 | if (!mst) | |
208 | return -ENOMEM; | |
209 | ||
210 | mst->ch.node_type = UBIFS_MST_NODE; | |
211 | mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); | |
212 | mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); | |
213 | mst->cmt_no = 0; | |
214 | mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); | |
215 | mst->root_offs = 0; | |
216 | tmp = ubifs_idx_node_sz(c, 1); | |
217 | mst->root_len = cpu_to_le32(tmp); | |
218 | mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); | |
219 | mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); | |
220 | mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); | |
221 | mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); | |
222 | mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); | |
223 | mst->lpt_offs = cpu_to_le32(c->lpt_offs); | |
224 | mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); | |
225 | mst->nhead_offs = cpu_to_le32(c->nhead_offs); | |
226 | mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); | |
227 | mst->ltab_offs = cpu_to_le32(c->ltab_offs); | |
228 | mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); | |
229 | mst->lsave_offs = cpu_to_le32(c->lsave_offs); | |
230 | mst->lscan_lnum = cpu_to_le32(main_first); | |
231 | mst->empty_lebs = cpu_to_le32(main_lebs - 2); | |
232 | mst->idx_lebs = cpu_to_le32(1); | |
233 | mst->leb_cnt = cpu_to_le32(c->leb_cnt); | |
234 | ||
235 | /* Calculate lprops statistics */ | |
236 | tmp64 = main_bytes; | |
237 | tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); | |
238 | tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); | |
239 | mst->total_free = cpu_to_le64(tmp64); | |
240 | ||
241 | tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); | |
242 | ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - | |
243 | UBIFS_INO_NODE_SZ; | |
244 | tmp64 += ino_waste; | |
245 | tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); | |
246 | mst->total_dirty = cpu_to_le64(tmp64); | |
247 | ||
248 | /* The indexing LEB does not contribute to dark space */ | |
249 | tmp64 = (c->main_lebs - 1) * c->dark_wm; | |
250 | mst->total_dark = cpu_to_le64(tmp64); | |
251 | ||
252 | mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); | |
253 | ||
254 | err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, | |
255 | UBI_UNKNOWN); | |
256 | if (err) { | |
257 | kfree(mst); | |
258 | return err; | |
259 | } | |
260 | err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0, | |
261 | UBI_UNKNOWN); | |
262 | kfree(mst); | |
263 | if (err) | |
264 | return err; | |
265 | ||
266 | dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); | |
267 | ||
268 | /* Create the root indexing node */ | |
269 | tmp = ubifs_idx_node_sz(c, 1); | |
270 | idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL); | |
271 | if (!idx) | |
272 | return -ENOMEM; | |
273 | ||
274 | c->key_fmt = UBIFS_SIMPLE_KEY_FMT; | |
275 | c->key_hash = key_r5_hash; | |
276 | ||
277 | idx->ch.node_type = UBIFS_IDX_NODE; | |
278 | idx->child_cnt = cpu_to_le16(1); | |
279 | ino_key_init(c, &key, UBIFS_ROOT_INO); | |
280 | br = ubifs_idx_branch(c, idx, 0); | |
281 | key_write_idx(c, &key, &br->key); | |
282 | br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); | |
283 | br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); | |
284 | err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0, | |
285 | UBI_UNKNOWN); | |
286 | kfree(idx); | |
287 | if (err) | |
288 | return err; | |
289 | ||
290 | dbg_gen("default root indexing node created LEB %d:0", | |
291 | main_first + DEFAULT_IDX_LEB); | |
292 | ||
293 | /* Create default root inode */ | |
294 | tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); | |
295 | ino = kzalloc(tmp, GFP_KERNEL); | |
296 | if (!ino) | |
297 | return -ENOMEM; | |
298 | ||
299 | ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); | |
300 | ino->ch.node_type = UBIFS_INO_NODE; | |
301 | ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); | |
302 | ino->nlink = cpu_to_le32(2); | |
0ecb9529 HH |
303 | tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec); |
304 | ino->atime_sec = tmp_le64; | |
305 | ino->ctime_sec = tmp_le64; | |
306 | ino->mtime_sec = tmp_le64; | |
1e51764a AB |
307 | ino->atime_nsec = 0; |
308 | ino->ctime_nsec = 0; | |
309 | ino->mtime_nsec = 0; | |
310 | ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); | |
311 | ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); | |
312 | ||
313 | /* Set compression enabled by default */ | |
314 | ino->flags = cpu_to_le32(UBIFS_COMPR_FL); | |
315 | ||
316 | err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, | |
317 | main_first + DEFAULT_DATA_LEB, 0, | |
318 | UBI_UNKNOWN); | |
319 | kfree(ino); | |
320 | if (err) | |
321 | return err; | |
322 | ||
323 | dbg_gen("root inode created at LEB %d:0", | |
324 | main_first + DEFAULT_DATA_LEB); | |
325 | ||
326 | /* | |
327 | * The first node in the log has to be the commit start node. This is | |
328 | * always the case during normal file-system operation. Write a fake | |
329 | * commit start node to the log. | |
330 | */ | |
331 | tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size); | |
332 | cs = kzalloc(tmp, GFP_KERNEL); | |
333 | if (!cs) | |
334 | return -ENOMEM; | |
335 | ||
336 | cs->ch.node_type = UBIFS_CS_NODE; | |
337 | err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, | |
338 | 0, UBI_UNKNOWN); | |
339 | kfree(cs); | |
340 | ||
341 | ubifs_msg("default file-system created"); | |
342 | return 0; | |
343 | } | |
344 | ||
345 | /** | |
346 | * validate_sb - validate superblock node. | |
347 | * @c: UBIFS file-system description object | |
348 | * @sup: superblock node | |
349 | * | |
350 | * This function validates superblock node @sup. Since most of data was read | |
351 | * from the superblock and stored in @c, the function validates fields in @c | |
352 | * instead. Returns zero in case of success and %-EINVAL in case of validation | |
353 | * failure. | |
354 | */ | |
355 | static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) | |
356 | { | |
357 | long long max_bytes; | |
358 | int err = 1, min_leb_cnt; | |
359 | ||
360 | if (!c->key_hash) { | |
361 | err = 2; | |
362 | goto failed; | |
363 | } | |
364 | ||
365 | if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { | |
366 | err = 3; | |
367 | goto failed; | |
368 | } | |
369 | ||
370 | if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { | |
371 | ubifs_err("min. I/O unit mismatch: %d in superblock, %d real", | |
372 | le32_to_cpu(sup->min_io_size), c->min_io_size); | |
373 | goto failed; | |
374 | } | |
375 | ||
376 | if (le32_to_cpu(sup->leb_size) != c->leb_size) { | |
377 | ubifs_err("LEB size mismatch: %d in superblock, %d real", | |
378 | le32_to_cpu(sup->leb_size), c->leb_size); | |
379 | goto failed; | |
380 | } | |
381 | ||
382 | if (c->log_lebs < UBIFS_MIN_LOG_LEBS || | |
383 | c->lpt_lebs < UBIFS_MIN_LPT_LEBS || | |
384 | c->orph_lebs < UBIFS_MIN_ORPH_LEBS || | |
385 | c->main_lebs < UBIFS_MIN_MAIN_LEBS) { | |
386 | err = 4; | |
387 | goto failed; | |
388 | } | |
389 | ||
390 | /* | |
391 | * Calculate minimum allowed amount of main area LEBs. This is very | |
392 | * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we | |
393 | * have just read from the superblock. | |
394 | */ | |
395 | min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; | |
396 | min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; | |
397 | ||
398 | if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { | |
399 | ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, " | |
400 | "%d minimum required", c->leb_cnt, c->vi.size, | |
401 | min_leb_cnt); | |
402 | goto failed; | |
403 | } | |
404 | ||
405 | if (c->max_leb_cnt < c->leb_cnt) { | |
406 | ubifs_err("max. LEB count %d less than LEB count %d", | |
407 | c->max_leb_cnt, c->leb_cnt); | |
408 | goto failed; | |
409 | } | |
410 | ||
411 | if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { | |
412 | err = 7; | |
413 | goto failed; | |
414 | } | |
415 | ||
416 | if (c->max_bud_bytes < (long long)c->leb_size * UBIFS_MIN_BUD_LEBS || | |
417 | c->max_bud_bytes > (long long)c->leb_size * c->main_lebs) { | |
418 | err = 8; | |
419 | goto failed; | |
420 | } | |
421 | ||
422 | if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || | |
423 | c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { | |
424 | err = 9; | |
425 | goto failed; | |
426 | } | |
427 | ||
428 | if (c->fanout < UBIFS_MIN_FANOUT || | |
429 | ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { | |
430 | err = 10; | |
431 | goto failed; | |
432 | } | |
433 | ||
434 | if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && | |
435 | c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - | |
436 | c->log_lebs - c->lpt_lebs - c->orph_lebs)) { | |
437 | err = 11; | |
438 | goto failed; | |
439 | } | |
440 | ||
441 | if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + | |
442 | c->orph_lebs + c->main_lebs != c->leb_cnt) { | |
443 | err = 12; | |
444 | goto failed; | |
445 | } | |
446 | ||
447 | if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) { | |
448 | err = 13; | |
449 | goto failed; | |
450 | } | |
451 | ||
452 | max_bytes = c->main_lebs * (long long)c->leb_size; | |
453 | if (c->rp_size < 0 || max_bytes < c->rp_size) { | |
454 | err = 14; | |
455 | goto failed; | |
456 | } | |
457 | ||
458 | if (le32_to_cpu(sup->time_gran) > 1000000000 || | |
459 | le32_to_cpu(sup->time_gran) < 1) { | |
460 | err = 15; | |
461 | goto failed; | |
462 | } | |
463 | ||
464 | return 0; | |
465 | ||
466 | failed: | |
467 | ubifs_err("bad superblock, error %d", err); | |
468 | dbg_dump_node(c, sup); | |
469 | return -EINVAL; | |
470 | } | |
471 | ||
472 | /** | |
473 | * ubifs_read_sb_node - read superblock node. | |
474 | * @c: UBIFS file-system description object | |
475 | * | |
476 | * This function returns a pointer to the superblock node or a negative error | |
477 | * code. | |
478 | */ | |
479 | struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) | |
480 | { | |
481 | struct ubifs_sb_node *sup; | |
482 | int err; | |
483 | ||
484 | sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); | |
485 | if (!sup) | |
486 | return ERR_PTR(-ENOMEM); | |
487 | ||
488 | err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, | |
489 | UBIFS_SB_LNUM, 0); | |
490 | if (err) { | |
491 | kfree(sup); | |
492 | return ERR_PTR(err); | |
493 | } | |
494 | ||
495 | return sup; | |
496 | } | |
497 | ||
498 | /** | |
499 | * ubifs_write_sb_node - write superblock node. | |
500 | * @c: UBIFS file-system description object | |
501 | * @sup: superblock node read with 'ubifs_read_sb_node()' | |
502 | * | |
503 | * This function returns %0 on success and a negative error code on failure. | |
504 | */ | |
505 | int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) | |
506 | { | |
507 | int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); | |
508 | ||
509 | ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1); | |
510 | return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM); | |
511 | } | |
512 | ||
513 | /** | |
514 | * ubifs_read_superblock - read superblock. | |
515 | * @c: UBIFS file-system description object | |
516 | * | |
517 | * This function finds, reads and checks the superblock. If an empty UBI volume | |
518 | * is being mounted, this function creates default superblock. Returns zero in | |
519 | * case of success, and a negative error code in case of failure. | |
520 | */ | |
521 | int ubifs_read_superblock(struct ubifs_info *c) | |
522 | { | |
523 | int err, sup_flags; | |
524 | struct ubifs_sb_node *sup; | |
525 | ||
526 | if (c->empty) { | |
527 | err = create_default_filesystem(c); | |
528 | if (err) | |
529 | return err; | |
530 | } | |
531 | ||
532 | sup = ubifs_read_sb_node(c); | |
533 | if (IS_ERR(sup)) | |
534 | return PTR_ERR(sup); | |
535 | ||
963f0cf6 AB |
536 | c->fmt_version = le32_to_cpu(sup->fmt_version); |
537 | c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); | |
538 | ||
1e51764a AB |
539 | /* |
540 | * The software supports all previous versions but not future versions, | |
541 | * due to the unavailability of time-travelling equipment. | |
542 | */ | |
1e51764a | 543 | if (c->fmt_version > UBIFS_FORMAT_VERSION) { |
963f0cf6 AB |
544 | struct super_block *sb = c->vfs_sb; |
545 | int mounting_ro = sb->s_flags & MS_RDONLY; | |
546 | ||
547 | ubifs_assert(!c->ro_media || mounting_ro); | |
548 | if (!mounting_ro || | |
549 | c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { | |
550 | ubifs_err("on-flash format version is w%d/r%d, but " | |
551 | "software only supports up to version " | |
552 | "w%d/r%d", c->fmt_version, | |
553 | c->ro_compat_version, UBIFS_FORMAT_VERSION, | |
554 | UBIFS_RO_COMPAT_VERSION); | |
555 | if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { | |
556 | ubifs_msg("only R/O mounting is possible"); | |
557 | err = -EROFS; | |
558 | } else | |
559 | err = -EINVAL; | |
560 | goto out; | |
561 | } | |
562 | ||
563 | /* | |
564 | * The FS is mounted R/O, and the media format is | |
565 | * R/O-compatible with the UBIFS implementation, so we can | |
566 | * mount. | |
567 | */ | |
568 | c->rw_incompat = 1; | |
1e51764a AB |
569 | } |
570 | ||
571 | if (c->fmt_version < 3) { | |
572 | ubifs_err("on-flash format version %d is not supported", | |
573 | c->fmt_version); | |
574 | err = -EINVAL; | |
575 | goto out; | |
576 | } | |
577 | ||
578 | switch (sup->key_hash) { | |
579 | case UBIFS_KEY_HASH_R5: | |
580 | c->key_hash = key_r5_hash; | |
581 | c->key_hash_type = UBIFS_KEY_HASH_R5; | |
582 | break; | |
583 | ||
584 | case UBIFS_KEY_HASH_TEST: | |
585 | c->key_hash = key_test_hash; | |
586 | c->key_hash_type = UBIFS_KEY_HASH_TEST; | |
587 | break; | |
588 | }; | |
589 | ||
590 | c->key_fmt = sup->key_fmt; | |
591 | ||
592 | switch (c->key_fmt) { | |
593 | case UBIFS_SIMPLE_KEY_FMT: | |
594 | c->key_len = UBIFS_SK_LEN; | |
595 | break; | |
596 | default: | |
597 | ubifs_err("unsupported key format"); | |
598 | err = -EINVAL; | |
599 | goto out; | |
600 | } | |
601 | ||
602 | c->leb_cnt = le32_to_cpu(sup->leb_cnt); | |
603 | c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); | |
604 | c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); | |
605 | c->log_lebs = le32_to_cpu(sup->log_lebs); | |
606 | c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); | |
607 | c->orph_lebs = le32_to_cpu(sup->orph_lebs); | |
608 | c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; | |
609 | c->fanout = le32_to_cpu(sup->fanout); | |
610 | c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); | |
1e51764a AB |
611 | c->rp_size = le64_to_cpu(sup->rp_size); |
612 | c->rp_uid = le32_to_cpu(sup->rp_uid); | |
613 | c->rp_gid = le32_to_cpu(sup->rp_gid); | |
614 | sup_flags = le32_to_cpu(sup->flags); | |
553dea4d AB |
615 | if (!c->mount_opts.override_compr) |
616 | c->default_compr = le16_to_cpu(sup->default_compr); | |
1e51764a AB |
617 | |
618 | c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); | |
1e51764a | 619 | memcpy(&c->uuid, &sup->uuid, 16); |
1e51764a AB |
620 | c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); |
621 | ||
622 | /* Automatically increase file system size to the maximum size */ | |
623 | c->old_leb_cnt = c->leb_cnt; | |
624 | if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { | |
625 | c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); | |
626 | if (c->vfs_sb->s_flags & MS_RDONLY) | |
627 | dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs", | |
628 | c->old_leb_cnt, c->leb_cnt); | |
629 | else { | |
630 | dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs", | |
631 | c->old_leb_cnt, c->leb_cnt); | |
632 | sup->leb_cnt = cpu_to_le32(c->leb_cnt); | |
633 | err = ubifs_write_sb_node(c, sup); | |
634 | if (err) | |
635 | goto out; | |
636 | c->old_leb_cnt = c->leb_cnt; | |
637 | } | |
638 | } | |
639 | ||
640 | c->log_bytes = (long long)c->log_lebs * c->leb_size; | |
641 | c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; | |
642 | c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; | |
643 | c->lpt_last = c->lpt_first + c->lpt_lebs - 1; | |
644 | c->orph_first = c->lpt_last + 1; | |
645 | c->orph_last = c->orph_first + c->orph_lebs - 1; | |
646 | c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; | |
647 | c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; | |
648 | c->main_first = c->leb_cnt - c->main_lebs; | |
1e51764a AB |
649 | |
650 | err = validate_sb(c, sup); | |
651 | out: | |
652 | kfree(sup); | |
653 | return err; | |
654 | } |