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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> | |
31 | ||
32 | /* | |
33 | * Default journal size in logical eraseblocks as a percent of total | |
34 | * flash size. | |
35 | */ | |
36 | #define DEFAULT_JNL_PERCENT 5 | |
37 | ||
38 | /* Default maximum journal size in bytes */ | |
39 | #define DEFAULT_MAX_JNL (32*1024*1024) | |
40 | ||
41 | /* Default indexing tree fanout */ | |
42 | #define DEFAULT_FANOUT 8 | |
43 | ||
44 | /* Default number of data journal heads */ | |
45 | #define DEFAULT_JHEADS_CNT 1 | |
46 | ||
47 | /* Default positions of different LEBs in the main area */ | |
48 | #define DEFAULT_IDX_LEB 0 | |
49 | #define DEFAULT_DATA_LEB 1 | |
50 | #define DEFAULT_GC_LEB 2 | |
51 | ||
52 | /* Default number of LEB numbers in LPT's save table */ | |
53 | #define DEFAULT_LSAVE_CNT 256 | |
54 | ||
55 | /* Default reserved pool size as a percent of maximum free space */ | |
56 | #define DEFAULT_RP_PERCENT 5 | |
57 | ||
58 | /* The default maximum size of reserved pool in bytes */ | |
59 | #define DEFAULT_MAX_RP_SIZE (5*1024*1024) | |
60 | ||
61 | /* Default time granularity in nanoseconds */ | |
62 | #define DEFAULT_TIME_GRAN 1000000000 | |
63 | ||
64 | /** | |
65 | * create_default_filesystem - format empty UBI volume. | |
66 | * @c: UBIFS file-system description object | |
67 | * | |
68 | * This function creates default empty file-system. Returns zero in case of | |
69 | * success and a negative error code in case of failure. | |
70 | */ | |
71 | static int create_default_filesystem(struct ubifs_info *c) | |
72 | { | |
73 | struct ubifs_sb_node *sup; | |
74 | struct ubifs_mst_node *mst; | |
75 | struct ubifs_idx_node *idx; | |
76 | struct ubifs_branch *br; | |
77 | struct ubifs_ino_node *ino; | |
78 | struct ubifs_cs_node *cs; | |
79 | union ubifs_key key; | |
80 | int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; | |
81 | int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; | |
82 | int min_leb_cnt = UBIFS_MIN_LEB_CNT; | |
83 | uint64_t tmp64, main_bytes; | |
84 | ||
85 | /* Some functions called from here depend on the @c->key_len filed */ | |
86 | c->key_len = UBIFS_SK_LEN; | |
87 | ||
88 | /* | |
89 | * First of all, we have to calculate default file-system geometry - | |
90 | * log size, journal size, etc. | |
91 | */ | |
92 | if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) | |
93 | /* We can first multiply then divide and have no overflow */ | |
94 | jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; | |
95 | else | |
96 | jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; | |
97 | ||
98 | if (jnl_lebs < UBIFS_MIN_JNL_LEBS) | |
99 | jnl_lebs = UBIFS_MIN_JNL_LEBS; | |
100 | if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) | |
101 | jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; | |
102 | ||
103 | /* | |
104 | * The log should be large enough to fit reference nodes for all bud | |
105 | * LEBs. Because buds do not have to start from the beginning of LEBs | |
106 | * (half of the LEB may contain committed data), the log should | |
107 | * generally be larger, make it twice as large. | |
108 | */ | |
109 | tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; | |
110 | log_lebs = tmp / c->leb_size; | |
111 | /* Plus one LEB reserved for commit */ | |
112 | log_lebs += 1; | |
113 | if (c->leb_cnt - min_leb_cnt > 8) { | |
114 | /* And some extra space to allow writes while committing */ | |
115 | log_lebs += 1; | |
116 | min_leb_cnt += 1; | |
117 | } | |
118 | ||
119 | max_buds = jnl_lebs - log_lebs; | |
120 | if (max_buds < UBIFS_MIN_BUD_LEBS) | |
121 | max_buds = UBIFS_MIN_BUD_LEBS; | |
122 | ||
123 | /* | |
124 | * Orphan nodes are stored in a separate area. One node can store a lot | |
125 | * of orphan inode numbers, but when new orphan comes we just add a new | |
126 | * orphan node. At some point the nodes are consolidated into one | |
127 | * orphan node. | |
128 | */ | |
129 | orph_lebs = UBIFS_MIN_ORPH_LEBS; | |
130 | #ifdef CONFIG_UBIFS_FS_DEBUG | |
131 | if (c->leb_cnt - min_leb_cnt > 1) | |
132 | /* | |
133 | * For debugging purposes it is better to have at least 2 | |
134 | * orphan LEBs, because the orphan subsystem would need to do | |
135 | * consolidations and would be stressed more. | |
136 | */ | |
137 | orph_lebs += 1; | |
138 | #endif | |
139 | ||
140 | main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; | |
141 | main_lebs -= orph_lebs; | |
142 | ||
143 | lpt_first = UBIFS_LOG_LNUM + log_lebs; | |
144 | c->lsave_cnt = DEFAULT_LSAVE_CNT; | |
145 | c->max_leb_cnt = c->leb_cnt; | |
146 | err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, | |
147 | &big_lpt); | |
148 | if (err) | |
149 | return err; | |
150 | ||
151 | dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, | |
152 | lpt_first + lpt_lebs - 1); | |
153 | ||
154 | main_first = c->leb_cnt - main_lebs; | |
155 | ||
156 | /* Create default superblock */ | |
157 | tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); | |
158 | sup = kzalloc(tmp, GFP_KERNEL); | |
159 | if (!sup) | |
160 | return -ENOMEM; | |
161 | ||
162 | tmp64 = (uint64_t)max_buds * c->leb_size; | |
163 | if (big_lpt) | |
164 | sup_flags |= UBIFS_FLG_BIGLPT; | |
165 | ||
166 | sup->ch.node_type = UBIFS_SB_NODE; | |
167 | sup->key_hash = UBIFS_KEY_HASH_R5; | |
168 | sup->flags = cpu_to_le32(sup_flags); | |
169 | sup->min_io_size = cpu_to_le32(c->min_io_size); | |
170 | sup->leb_size = cpu_to_le32(c->leb_size); | |
171 | sup->leb_cnt = cpu_to_le32(c->leb_cnt); | |
172 | sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); | |
173 | sup->max_bud_bytes = cpu_to_le64(tmp64); | |
174 | sup->log_lebs = cpu_to_le32(log_lebs); | |
175 | sup->lpt_lebs = cpu_to_le32(lpt_lebs); | |
176 | sup->orph_lebs = cpu_to_le32(orph_lebs); | |
177 | sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); | |
178 | sup->fanout = cpu_to_le32(DEFAULT_FANOUT); | |
179 | sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); | |
180 | sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION); | |
181 | sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO); | |
182 | sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); | |
183 | ||
184 | generate_random_uuid(sup->uuid); | |
185 | ||
186 | main_bytes = (uint64_t)main_lebs * c->leb_size; | |
187 | tmp64 = main_bytes * DEFAULT_RP_PERCENT; | |
188 | do_div(tmp64, 100); | |
189 | if (tmp64 > DEFAULT_MAX_RP_SIZE) | |
190 | tmp64 = DEFAULT_MAX_RP_SIZE; | |
191 | sup->rp_size = cpu_to_le64(tmp64); | |
192 | ||
193 | err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM); | |
194 | kfree(sup); | |
195 | if (err) | |
196 | return err; | |
197 | ||
198 | dbg_gen("default superblock created at LEB 0:0"); | |
199 | ||
200 | /* Create default master node */ | |
201 | mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); | |
202 | if (!mst) | |
203 | return -ENOMEM; | |
204 | ||
205 | mst->ch.node_type = UBIFS_MST_NODE; | |
206 | mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); | |
207 | mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); | |
208 | mst->cmt_no = 0; | |
209 | mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); | |
210 | mst->root_offs = 0; | |
211 | tmp = ubifs_idx_node_sz(c, 1); | |
212 | mst->root_len = cpu_to_le32(tmp); | |
213 | mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); | |
214 | mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); | |
215 | mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); | |
216 | mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); | |
217 | mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); | |
218 | mst->lpt_offs = cpu_to_le32(c->lpt_offs); | |
219 | mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); | |
220 | mst->nhead_offs = cpu_to_le32(c->nhead_offs); | |
221 | mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); | |
222 | mst->ltab_offs = cpu_to_le32(c->ltab_offs); | |
223 | mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); | |
224 | mst->lsave_offs = cpu_to_le32(c->lsave_offs); | |
225 | mst->lscan_lnum = cpu_to_le32(main_first); | |
226 | mst->empty_lebs = cpu_to_le32(main_lebs - 2); | |
227 | mst->idx_lebs = cpu_to_le32(1); | |
228 | mst->leb_cnt = cpu_to_le32(c->leb_cnt); | |
229 | ||
230 | /* Calculate lprops statistics */ | |
231 | tmp64 = main_bytes; | |
232 | tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); | |
233 | tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); | |
234 | mst->total_free = cpu_to_le64(tmp64); | |
235 | ||
236 | tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); | |
237 | ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - | |
238 | UBIFS_INO_NODE_SZ; | |
239 | tmp64 += ino_waste; | |
240 | tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); | |
241 | mst->total_dirty = cpu_to_le64(tmp64); | |
242 | ||
243 | /* The indexing LEB does not contribute to dark space */ | |
244 | tmp64 = (c->main_lebs - 1) * c->dark_wm; | |
245 | mst->total_dark = cpu_to_le64(tmp64); | |
246 | ||
247 | mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); | |
248 | ||
249 | err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, | |
250 | UBI_UNKNOWN); | |
251 | if (err) { | |
252 | kfree(mst); | |
253 | return err; | |
254 | } | |
255 | err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0, | |
256 | UBI_UNKNOWN); | |
257 | kfree(mst); | |
258 | if (err) | |
259 | return err; | |
260 | ||
261 | dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); | |
262 | ||
263 | /* Create the root indexing node */ | |
264 | tmp = ubifs_idx_node_sz(c, 1); | |
265 | idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL); | |
266 | if (!idx) | |
267 | return -ENOMEM; | |
268 | ||
269 | c->key_fmt = UBIFS_SIMPLE_KEY_FMT; | |
270 | c->key_hash = key_r5_hash; | |
271 | ||
272 | idx->ch.node_type = UBIFS_IDX_NODE; | |
273 | idx->child_cnt = cpu_to_le16(1); | |
274 | ino_key_init(c, &key, UBIFS_ROOT_INO); | |
275 | br = ubifs_idx_branch(c, idx, 0); | |
276 | key_write_idx(c, &key, &br->key); | |
277 | br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); | |
278 | br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); | |
279 | err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0, | |
280 | UBI_UNKNOWN); | |
281 | kfree(idx); | |
282 | if (err) | |
283 | return err; | |
284 | ||
285 | dbg_gen("default root indexing node created LEB %d:0", | |
286 | main_first + DEFAULT_IDX_LEB); | |
287 | ||
288 | /* Create default root inode */ | |
289 | tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); | |
290 | ino = kzalloc(tmp, GFP_KERNEL); | |
291 | if (!ino) | |
292 | return -ENOMEM; | |
293 | ||
294 | ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); | |
295 | ino->ch.node_type = UBIFS_INO_NODE; | |
296 | ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); | |
297 | ino->nlink = cpu_to_le32(2); | |
298 | tmp = cpu_to_le64(CURRENT_TIME_SEC.tv_sec); | |
299 | ino->atime_sec = tmp; | |
300 | ino->ctime_sec = tmp; | |
301 | ino->mtime_sec = tmp; | |
302 | ino->atime_nsec = 0; | |
303 | ino->ctime_nsec = 0; | |
304 | ino->mtime_nsec = 0; | |
305 | ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); | |
306 | ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); | |
307 | ||
308 | /* Set compression enabled by default */ | |
309 | ino->flags = cpu_to_le32(UBIFS_COMPR_FL); | |
310 | ||
311 | err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, | |
312 | main_first + DEFAULT_DATA_LEB, 0, | |
313 | UBI_UNKNOWN); | |
314 | kfree(ino); | |
315 | if (err) | |
316 | return err; | |
317 | ||
318 | dbg_gen("root inode created at LEB %d:0", | |
319 | main_first + DEFAULT_DATA_LEB); | |
320 | ||
321 | /* | |
322 | * The first node in the log has to be the commit start node. This is | |
323 | * always the case during normal file-system operation. Write a fake | |
324 | * commit start node to the log. | |
325 | */ | |
326 | tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size); | |
327 | cs = kzalloc(tmp, GFP_KERNEL); | |
328 | if (!cs) | |
329 | return -ENOMEM; | |
330 | ||
331 | cs->ch.node_type = UBIFS_CS_NODE; | |
332 | err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, | |
333 | 0, UBI_UNKNOWN); | |
334 | kfree(cs); | |
335 | ||
336 | ubifs_msg("default file-system created"); | |
337 | return 0; | |
338 | } | |
339 | ||
340 | /** | |
341 | * validate_sb - validate superblock node. | |
342 | * @c: UBIFS file-system description object | |
343 | * @sup: superblock node | |
344 | * | |
345 | * This function validates superblock node @sup. Since most of data was read | |
346 | * from the superblock and stored in @c, the function validates fields in @c | |
347 | * instead. Returns zero in case of success and %-EINVAL in case of validation | |
348 | * failure. | |
349 | */ | |
350 | static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) | |
351 | { | |
352 | long long max_bytes; | |
353 | int err = 1, min_leb_cnt; | |
354 | ||
355 | if (!c->key_hash) { | |
356 | err = 2; | |
357 | goto failed; | |
358 | } | |
359 | ||
360 | if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { | |
361 | err = 3; | |
362 | goto failed; | |
363 | } | |
364 | ||
365 | if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { | |
366 | ubifs_err("min. I/O unit mismatch: %d in superblock, %d real", | |
367 | le32_to_cpu(sup->min_io_size), c->min_io_size); | |
368 | goto failed; | |
369 | } | |
370 | ||
371 | if (le32_to_cpu(sup->leb_size) != c->leb_size) { | |
372 | ubifs_err("LEB size mismatch: %d in superblock, %d real", | |
373 | le32_to_cpu(sup->leb_size), c->leb_size); | |
374 | goto failed; | |
375 | } | |
376 | ||
377 | if (c->log_lebs < UBIFS_MIN_LOG_LEBS || | |
378 | c->lpt_lebs < UBIFS_MIN_LPT_LEBS || | |
379 | c->orph_lebs < UBIFS_MIN_ORPH_LEBS || | |
380 | c->main_lebs < UBIFS_MIN_MAIN_LEBS) { | |
381 | err = 4; | |
382 | goto failed; | |
383 | } | |
384 | ||
385 | /* | |
386 | * Calculate minimum allowed amount of main area LEBs. This is very | |
387 | * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we | |
388 | * have just read from the superblock. | |
389 | */ | |
390 | min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; | |
391 | min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; | |
392 | ||
393 | if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { | |
394 | ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, " | |
395 | "%d minimum required", c->leb_cnt, c->vi.size, | |
396 | min_leb_cnt); | |
397 | goto failed; | |
398 | } | |
399 | ||
400 | if (c->max_leb_cnt < c->leb_cnt) { | |
401 | ubifs_err("max. LEB count %d less than LEB count %d", | |
402 | c->max_leb_cnt, c->leb_cnt); | |
403 | goto failed; | |
404 | } | |
405 | ||
406 | if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { | |
407 | err = 7; | |
408 | goto failed; | |
409 | } | |
410 | ||
411 | if (c->max_bud_bytes < (long long)c->leb_size * UBIFS_MIN_BUD_LEBS || | |
412 | c->max_bud_bytes > (long long)c->leb_size * c->main_lebs) { | |
413 | err = 8; | |
414 | goto failed; | |
415 | } | |
416 | ||
417 | if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || | |
418 | c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { | |
419 | err = 9; | |
420 | goto failed; | |
421 | } | |
422 | ||
423 | if (c->fanout < UBIFS_MIN_FANOUT || | |
424 | ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { | |
425 | err = 10; | |
426 | goto failed; | |
427 | } | |
428 | ||
429 | if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && | |
430 | c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - | |
431 | c->log_lebs - c->lpt_lebs - c->orph_lebs)) { | |
432 | err = 11; | |
433 | goto failed; | |
434 | } | |
435 | ||
436 | if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + | |
437 | c->orph_lebs + c->main_lebs != c->leb_cnt) { | |
438 | err = 12; | |
439 | goto failed; | |
440 | } | |
441 | ||
442 | if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) { | |
443 | err = 13; | |
444 | goto failed; | |
445 | } | |
446 | ||
447 | max_bytes = c->main_lebs * (long long)c->leb_size; | |
448 | if (c->rp_size < 0 || max_bytes < c->rp_size) { | |
449 | err = 14; | |
450 | goto failed; | |
451 | } | |
452 | ||
453 | if (le32_to_cpu(sup->time_gran) > 1000000000 || | |
454 | le32_to_cpu(sup->time_gran) < 1) { | |
455 | err = 15; | |
456 | goto failed; | |
457 | } | |
458 | ||
459 | return 0; | |
460 | ||
461 | failed: | |
462 | ubifs_err("bad superblock, error %d", err); | |
463 | dbg_dump_node(c, sup); | |
464 | return -EINVAL; | |
465 | } | |
466 | ||
467 | /** | |
468 | * ubifs_read_sb_node - read superblock node. | |
469 | * @c: UBIFS file-system description object | |
470 | * | |
471 | * This function returns a pointer to the superblock node or a negative error | |
472 | * code. | |
473 | */ | |
474 | struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) | |
475 | { | |
476 | struct ubifs_sb_node *sup; | |
477 | int err; | |
478 | ||
479 | sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); | |
480 | if (!sup) | |
481 | return ERR_PTR(-ENOMEM); | |
482 | ||
483 | err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, | |
484 | UBIFS_SB_LNUM, 0); | |
485 | if (err) { | |
486 | kfree(sup); | |
487 | return ERR_PTR(err); | |
488 | } | |
489 | ||
490 | return sup; | |
491 | } | |
492 | ||
493 | /** | |
494 | * ubifs_write_sb_node - write superblock node. | |
495 | * @c: UBIFS file-system description object | |
496 | * @sup: superblock node read with 'ubifs_read_sb_node()' | |
497 | * | |
498 | * This function returns %0 on success and a negative error code on failure. | |
499 | */ | |
500 | int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) | |
501 | { | |
502 | int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); | |
503 | ||
504 | ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1); | |
505 | return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM); | |
506 | } | |
507 | ||
508 | /** | |
509 | * ubifs_read_superblock - read superblock. | |
510 | * @c: UBIFS file-system description object | |
511 | * | |
512 | * This function finds, reads and checks the superblock. If an empty UBI volume | |
513 | * is being mounted, this function creates default superblock. Returns zero in | |
514 | * case of success, and a negative error code in case of failure. | |
515 | */ | |
516 | int ubifs_read_superblock(struct ubifs_info *c) | |
517 | { | |
518 | int err, sup_flags; | |
519 | struct ubifs_sb_node *sup; | |
520 | ||
521 | if (c->empty) { | |
522 | err = create_default_filesystem(c); | |
523 | if (err) | |
524 | return err; | |
525 | } | |
526 | ||
527 | sup = ubifs_read_sb_node(c); | |
528 | if (IS_ERR(sup)) | |
529 | return PTR_ERR(sup); | |
530 | ||
531 | /* | |
532 | * The software supports all previous versions but not future versions, | |
533 | * due to the unavailability of time-travelling equipment. | |
534 | */ | |
535 | c->fmt_version = le32_to_cpu(sup->fmt_version); | |
536 | if (c->fmt_version > UBIFS_FORMAT_VERSION) { | |
537 | ubifs_err("on-flash format version is %d, but software only " | |
538 | "supports up to version %d", c->fmt_version, | |
539 | UBIFS_FORMAT_VERSION); | |
540 | err = -EINVAL; | |
541 | goto out; | |
542 | } | |
543 | ||
544 | if (c->fmt_version < 3) { | |
545 | ubifs_err("on-flash format version %d is not supported", | |
546 | c->fmt_version); | |
547 | err = -EINVAL; | |
548 | goto out; | |
549 | } | |
550 | ||
551 | switch (sup->key_hash) { | |
552 | case UBIFS_KEY_HASH_R5: | |
553 | c->key_hash = key_r5_hash; | |
554 | c->key_hash_type = UBIFS_KEY_HASH_R5; | |
555 | break; | |
556 | ||
557 | case UBIFS_KEY_HASH_TEST: | |
558 | c->key_hash = key_test_hash; | |
559 | c->key_hash_type = UBIFS_KEY_HASH_TEST; | |
560 | break; | |
561 | }; | |
562 | ||
563 | c->key_fmt = sup->key_fmt; | |
564 | ||
565 | switch (c->key_fmt) { | |
566 | case UBIFS_SIMPLE_KEY_FMT: | |
567 | c->key_len = UBIFS_SK_LEN; | |
568 | break; | |
569 | default: | |
570 | ubifs_err("unsupported key format"); | |
571 | err = -EINVAL; | |
572 | goto out; | |
573 | } | |
574 | ||
575 | c->leb_cnt = le32_to_cpu(sup->leb_cnt); | |
576 | c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); | |
577 | c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); | |
578 | c->log_lebs = le32_to_cpu(sup->log_lebs); | |
579 | c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); | |
580 | c->orph_lebs = le32_to_cpu(sup->orph_lebs); | |
581 | c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; | |
582 | c->fanout = le32_to_cpu(sup->fanout); | |
583 | c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); | |
584 | c->default_compr = le16_to_cpu(sup->default_compr); | |
585 | c->rp_size = le64_to_cpu(sup->rp_size); | |
586 | c->rp_uid = le32_to_cpu(sup->rp_uid); | |
587 | c->rp_gid = le32_to_cpu(sup->rp_gid); | |
588 | sup_flags = le32_to_cpu(sup->flags); | |
589 | ||
590 | c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); | |
591 | ||
592 | memcpy(&c->uuid, &sup->uuid, 16); | |
593 | ||
594 | c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); | |
595 | ||
596 | /* Automatically increase file system size to the maximum size */ | |
597 | c->old_leb_cnt = c->leb_cnt; | |
598 | if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { | |
599 | c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); | |
600 | if (c->vfs_sb->s_flags & MS_RDONLY) | |
601 | dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs", | |
602 | c->old_leb_cnt, c->leb_cnt); | |
603 | else { | |
604 | dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs", | |
605 | c->old_leb_cnt, c->leb_cnt); | |
606 | sup->leb_cnt = cpu_to_le32(c->leb_cnt); | |
607 | err = ubifs_write_sb_node(c, sup); | |
608 | if (err) | |
609 | goto out; | |
610 | c->old_leb_cnt = c->leb_cnt; | |
611 | } | |
612 | } | |
613 | ||
614 | c->log_bytes = (long long)c->log_lebs * c->leb_size; | |
615 | c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; | |
616 | c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; | |
617 | c->lpt_last = c->lpt_first + c->lpt_lebs - 1; | |
618 | c->orph_first = c->lpt_last + 1; | |
619 | c->orph_last = c->orph_first + c->orph_lebs - 1; | |
620 | c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; | |
621 | c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; | |
622 | c->main_first = c->leb_cnt - c->main_lebs; | |
623 | c->report_rp_size = ubifs_reported_space(c, c->rp_size); | |
624 | ||
625 | err = validate_sb(c, sup); | |
626 | out: | |
627 | kfree(sup); | |
628 | return err; | |
629 | } |