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/slab.h>
31 #include <linux/math64.h>
32 #include <linux/uuid.h>
33
34 /*
35 * Default journal size in logical eraseblocks as a percent of total
36 * flash size.
37 */
38 #define DEFAULT_JNL_PERCENT 5
39
40 /* Default maximum journal size in bytes */
41 #define DEFAULT_MAX_JNL (32*1024*1024)
42
43 /* Default indexing tree fanout */
44 #define DEFAULT_FANOUT 8
45
46 /* Default number of data journal heads */
47 #define DEFAULT_JHEADS_CNT 1
48
49 /* Default positions of different LEBs in the main area */
50 #define DEFAULT_IDX_LEB 0
51 #define DEFAULT_DATA_LEB 1
52 #define DEFAULT_GC_LEB 2
53
54 /* Default number of LEB numbers in LPT's save table */
55 #define DEFAULT_LSAVE_CNT 256
56
57 /* Default reserved pool size as a percent of maximum free space */
58 #define DEFAULT_RP_PERCENT 5
59
60 /* The default maximum size of reserved pool in bytes */
61 #define DEFAULT_MAX_RP_SIZE (5*1024*1024)
62
63 /* Default time granularity in nanoseconds */
64 #define DEFAULT_TIME_GRAN 1000000000
65
get_default_compressor(struct ubifs_info * c)66 static int get_default_compressor(struct ubifs_info *c)
67 {
68 if (ubifs_compr_present(c, UBIFS_COMPR_LZO))
69 return UBIFS_COMPR_LZO;
70
71 if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB))
72 return UBIFS_COMPR_ZLIB;
73
74 return UBIFS_COMPR_NONE;
75 }
76
77 /**
78 * create_default_filesystem - format empty UBI volume.
79 * @c: UBIFS file-system description object
80 *
81 * This function creates default empty file-system. Returns zero in case of
82 * success and a negative error code in case of failure.
83 */
create_default_filesystem(struct ubifs_info * c)84 static int create_default_filesystem(struct ubifs_info *c)
85 {
86 struct ubifs_sb_node *sup;
87 struct ubifs_mst_node *mst;
88 struct ubifs_idx_node *idx;
89 struct ubifs_branch *br;
90 struct ubifs_ino_node *ino;
91 struct ubifs_cs_node *cs;
92 union ubifs_key key;
93 int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;
94 int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
95 int min_leb_cnt = UBIFS_MIN_LEB_CNT;
96 long long tmp64, main_bytes;
97 __le64 tmp_le64;
98 __le32 tmp_le32;
99 struct timespec64 ts;
100
101 /* Some functions called from here depend on the @c->key_len filed */
102 c->key_len = UBIFS_SK_LEN;
103
104 /*
105 * First of all, we have to calculate default file-system geometry -
106 * log size, journal size, etc.
107 */
108 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
109 /* We can first multiply then divide and have no overflow */
110 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
111 else
112 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
113
114 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
115 jnl_lebs = UBIFS_MIN_JNL_LEBS;
116 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
117 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
118
119 /*
120 * The log should be large enough to fit reference nodes for all bud
121 * LEBs. Because buds do not have to start from the beginning of LEBs
122 * (half of the LEB may contain committed data), the log should
123 * generally be larger, make it twice as large.
124 */
125 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
126 log_lebs = tmp / c->leb_size;
127 /* Plus one LEB reserved for commit */
128 log_lebs += 1;
129 if (c->leb_cnt - min_leb_cnt > 8) {
130 /* And some extra space to allow writes while committing */
131 log_lebs += 1;
132 min_leb_cnt += 1;
133 }
134
135 max_buds = jnl_lebs - log_lebs;
136 if (max_buds < UBIFS_MIN_BUD_LEBS)
137 max_buds = UBIFS_MIN_BUD_LEBS;
138
139 /*
140 * Orphan nodes are stored in a separate area. One node can store a lot
141 * of orphan inode numbers, but when new orphan comes we just add a new
142 * orphan node. At some point the nodes are consolidated into one
143 * orphan node.
144 */
145 orph_lebs = UBIFS_MIN_ORPH_LEBS;
146 if (c->leb_cnt - min_leb_cnt > 1)
147 /*
148 * For debugging purposes it is better to have at least 2
149 * orphan LEBs, because the orphan subsystem would need to do
150 * consolidations and would be stressed more.
151 */
152 orph_lebs += 1;
153
154 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
155 main_lebs -= orph_lebs;
156
157 lpt_first = UBIFS_LOG_LNUM + log_lebs;
158 c->lsave_cnt = DEFAULT_LSAVE_CNT;
159 c->max_leb_cnt = c->leb_cnt;
160 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
161 &big_lpt);
162 if (err)
163 return err;
164
165 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
166 lpt_first + lpt_lebs - 1);
167
168 main_first = c->leb_cnt - main_lebs;
169
170 /* Create default superblock */
171 tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
172 sup = kzalloc(tmp, GFP_KERNEL);
173 if (!sup)
174 return -ENOMEM;
175
176 tmp64 = (long long)max_buds * c->leb_size;
177 if (big_lpt)
178 sup_flags |= UBIFS_FLG_BIGLPT;
179 sup_flags |= UBIFS_FLG_DOUBLE_HASH;
180
181 sup->ch.node_type = UBIFS_SB_NODE;
182 sup->key_hash = UBIFS_KEY_HASH_R5;
183 sup->flags = cpu_to_le32(sup_flags);
184 sup->min_io_size = cpu_to_le32(c->min_io_size);
185 sup->leb_size = cpu_to_le32(c->leb_size);
186 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
187 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
188 sup->max_bud_bytes = cpu_to_le64(tmp64);
189 sup->log_lebs = cpu_to_le32(log_lebs);
190 sup->lpt_lebs = cpu_to_le32(lpt_lebs);
191 sup->orph_lebs = cpu_to_le32(orph_lebs);
192 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
193 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
194 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
195 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
196 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
197 if (c->mount_opts.override_compr)
198 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
199 else
200 sup->default_compr = cpu_to_le16(get_default_compressor(c));
201
202 generate_random_uuid(sup->uuid);
203
204 main_bytes = (long long)main_lebs * c->leb_size;
205 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
206 if (tmp64 > DEFAULT_MAX_RP_SIZE)
207 tmp64 = DEFAULT_MAX_RP_SIZE;
208 sup->rp_size = cpu_to_le64(tmp64);
209 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
210
211 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0);
212 kfree(sup);
213 if (err)
214 return err;
215
216 dbg_gen("default superblock created at LEB 0:0");
217
218 /* Create default master node */
219 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
220 if (!mst)
221 return -ENOMEM;
222
223 mst->ch.node_type = UBIFS_MST_NODE;
224 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
225 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
226 mst->cmt_no = 0;
227 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
228 mst->root_offs = 0;
229 tmp = ubifs_idx_node_sz(c, 1);
230 mst->root_len = cpu_to_le32(tmp);
231 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
232 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
233 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
234 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
235 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
236 mst->lpt_offs = cpu_to_le32(c->lpt_offs);
237 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
238 mst->nhead_offs = cpu_to_le32(c->nhead_offs);
239 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
240 mst->ltab_offs = cpu_to_le32(c->ltab_offs);
241 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
242 mst->lsave_offs = cpu_to_le32(c->lsave_offs);
243 mst->lscan_lnum = cpu_to_le32(main_first);
244 mst->empty_lebs = cpu_to_le32(main_lebs - 2);
245 mst->idx_lebs = cpu_to_le32(1);
246 mst->leb_cnt = cpu_to_le32(c->leb_cnt);
247
248 /* Calculate lprops statistics */
249 tmp64 = main_bytes;
250 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
251 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
252 mst->total_free = cpu_to_le64(tmp64);
253
254 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
255 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
256 UBIFS_INO_NODE_SZ;
257 tmp64 += ino_waste;
258 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
259 mst->total_dirty = cpu_to_le64(tmp64);
260
261 /* The indexing LEB does not contribute to dark space */
262 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
263 mst->total_dark = cpu_to_le64(tmp64);
264
265 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
266
267 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0);
268 if (err) {
269 kfree(mst);
270 return err;
271 }
272 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
273 0);
274 kfree(mst);
275 if (err)
276 return err;
277
278 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
279
280 /* Create the root indexing node */
281 tmp = ubifs_idx_node_sz(c, 1);
282 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
283 if (!idx)
284 return -ENOMEM;
285
286 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
287 c->key_hash = key_r5_hash;
288
289 idx->ch.node_type = UBIFS_IDX_NODE;
290 idx->child_cnt = cpu_to_le16(1);
291 ino_key_init(c, &key, UBIFS_ROOT_INO);
292 br = ubifs_idx_branch(c, idx, 0);
293 key_write_idx(c, &key, &br->key);
294 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
295 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
296 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0);
297 kfree(idx);
298 if (err)
299 return err;
300
301 dbg_gen("default root indexing node created LEB %d:0",
302 main_first + DEFAULT_IDX_LEB);
303
304 /* Create default root inode */
305 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
306 ino = kzalloc(tmp, GFP_KERNEL);
307 if (!ino)
308 return -ENOMEM;
309
310 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
311 ino->ch.node_type = UBIFS_INO_NODE;
312 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
313 ino->nlink = cpu_to_le32(2);
314
315 ktime_get_real_ts64(&ts);
316 ts = timespec64_trunc(ts, DEFAULT_TIME_GRAN);
317 tmp_le64 = cpu_to_le64(ts.tv_sec);
318 ino->atime_sec = tmp_le64;
319 ino->ctime_sec = tmp_le64;
320 ino->mtime_sec = tmp_le64;
321 tmp_le32 = cpu_to_le32(ts.tv_nsec);
322 ino->atime_nsec = tmp_le32;
323 ino->ctime_nsec = tmp_le32;
324 ino->mtime_nsec = tmp_le32;
325 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
326 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
327
328 /* Set compression enabled by default */
329 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
330
331 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
332 main_first + DEFAULT_DATA_LEB, 0);
333 kfree(ino);
334 if (err)
335 return err;
336
337 dbg_gen("root inode created at LEB %d:0",
338 main_first + DEFAULT_DATA_LEB);
339
340 /*
341 * The first node in the log has to be the commit start node. This is
342 * always the case during normal file-system operation. Write a fake
343 * commit start node to the log.
344 */
345 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
346 cs = kzalloc(tmp, GFP_KERNEL);
347 if (!cs)
348 return -ENOMEM;
349
350 cs->ch.node_type = UBIFS_CS_NODE;
351 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
352 kfree(cs);
353 if (err)
354 return err;
355
356 ubifs_msg(c, "default file-system created");
357 return 0;
358 }
359
360 /**
361 * validate_sb - validate superblock node.
362 * @c: UBIFS file-system description object
363 * @sup: superblock node
364 *
365 * This function validates superblock node @sup. Since most of data was read
366 * from the superblock and stored in @c, the function validates fields in @c
367 * instead. Returns zero in case of success and %-EINVAL in case of validation
368 * failure.
369 */
validate_sb(struct ubifs_info * c,struct ubifs_sb_node * sup)370 static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
371 {
372 long long max_bytes;
373 int err = 1, min_leb_cnt;
374
375 if (!c->key_hash) {
376 err = 2;
377 goto failed;
378 }
379
380 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
381 err = 3;
382 goto failed;
383 }
384
385 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
386 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real",
387 le32_to_cpu(sup->min_io_size), c->min_io_size);
388 goto failed;
389 }
390
391 if (le32_to_cpu(sup->leb_size) != c->leb_size) {
392 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real",
393 le32_to_cpu(sup->leb_size), c->leb_size);
394 goto failed;
395 }
396
397 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
398 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
399 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
400 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
401 err = 4;
402 goto failed;
403 }
404
405 /*
406 * Calculate minimum allowed amount of main area LEBs. This is very
407 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
408 * have just read from the superblock.
409 */
410 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
411 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
412
413 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
414 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
415 c->leb_cnt, c->vi.size, min_leb_cnt);
416 goto failed;
417 }
418
419 if (c->max_leb_cnt < c->leb_cnt) {
420 ubifs_err(c, "max. LEB count %d less than LEB count %d",
421 c->max_leb_cnt, c->leb_cnt);
422 goto failed;
423 }
424
425 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
426 ubifs_err(c, "too few main LEBs count %d, must be at least %d",
427 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
428 goto failed;
429 }
430
431 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
432 if (c->max_bud_bytes < max_bytes) {
433 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes",
434 c->max_bud_bytes, max_bytes);
435 goto failed;
436 }
437
438 max_bytes = (long long)c->leb_size * c->main_lebs;
439 if (c->max_bud_bytes > max_bytes) {
440 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area",
441 c->max_bud_bytes, max_bytes);
442 goto failed;
443 }
444
445 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
446 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
447 err = 9;
448 goto failed;
449 }
450
451 if (c->fanout < UBIFS_MIN_FANOUT ||
452 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
453 err = 10;
454 goto failed;
455 }
456
457 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
458 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
459 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
460 err = 11;
461 goto failed;
462 }
463
464 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
465 c->orph_lebs + c->main_lebs != c->leb_cnt) {
466 err = 12;
467 goto failed;
468 }
469
470 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
471 err = 13;
472 goto failed;
473 }
474
475 if (c->rp_size < 0 || max_bytes < c->rp_size) {
476 err = 14;
477 goto failed;
478 }
479
480 if (le32_to_cpu(sup->time_gran) > 1000000000 ||
481 le32_to_cpu(sup->time_gran) < 1) {
482 err = 15;
483 goto failed;
484 }
485
486 if (!c->double_hash && c->fmt_version >= 5) {
487 err = 16;
488 goto failed;
489 }
490
491 if (c->encrypted && c->fmt_version < 5) {
492 err = 17;
493 goto failed;
494 }
495
496 return 0;
497
498 failed:
499 ubifs_err(c, "bad superblock, error %d", err);
500 ubifs_dump_node(c, sup);
501 return -EINVAL;
502 }
503
504 /**
505 * ubifs_read_sb_node - read superblock node.
506 * @c: UBIFS file-system description object
507 *
508 * This function returns a pointer to the superblock node or a negative error
509 * code. Note, the user of this function is responsible of kfree()'ing the
510 * returned superblock buffer.
511 */
ubifs_read_sb_node(struct ubifs_info * c)512 struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
513 {
514 struct ubifs_sb_node *sup;
515 int err;
516
517 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
518 if (!sup)
519 return ERR_PTR(-ENOMEM);
520
521 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
522 UBIFS_SB_LNUM, 0);
523 if (err) {
524 kfree(sup);
525 return ERR_PTR(err);
526 }
527
528 return sup;
529 }
530
531 /**
532 * ubifs_write_sb_node - write superblock node.
533 * @c: UBIFS file-system description object
534 * @sup: superblock node read with 'ubifs_read_sb_node()'
535 *
536 * This function returns %0 on success and a negative error code on failure.
537 */
ubifs_write_sb_node(struct ubifs_info * c,struct ubifs_sb_node * sup)538 int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
539 {
540 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
541
542 ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
543 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);
544 }
545
546 /**
547 * ubifs_read_superblock - read superblock.
548 * @c: UBIFS file-system description object
549 *
550 * This function finds, reads and checks the superblock. If an empty UBI volume
551 * is being mounted, this function creates default superblock. Returns zero in
552 * case of success, and a negative error code in case of failure.
553 */
ubifs_read_superblock(struct ubifs_info * c)554 int ubifs_read_superblock(struct ubifs_info *c)
555 {
556 int err, sup_flags;
557 struct ubifs_sb_node *sup;
558
559 if (c->empty) {
560 err = create_default_filesystem(c);
561 if (err)
562 return err;
563 }
564
565 sup = ubifs_read_sb_node(c);
566 if (IS_ERR(sup))
567 return PTR_ERR(sup);
568
569 c->fmt_version = le32_to_cpu(sup->fmt_version);
570 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
571
572 /*
573 * The software supports all previous versions but not future versions,
574 * due to the unavailability of time-travelling equipment.
575 */
576 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
577 ubifs_assert(c, !c->ro_media || c->ro_mount);
578 if (!c->ro_mount ||
579 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
580 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
581 c->fmt_version, c->ro_compat_version,
582 UBIFS_FORMAT_VERSION,
583 UBIFS_RO_COMPAT_VERSION);
584 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
585 ubifs_msg(c, "only R/O mounting is possible");
586 err = -EROFS;
587 } else
588 err = -EINVAL;
589 goto out;
590 }
591
592 /*
593 * The FS is mounted R/O, and the media format is
594 * R/O-compatible with the UBIFS implementation, so we can
595 * mount.
596 */
597 c->rw_incompat = 1;
598 }
599
600 if (c->fmt_version < 3) {
601 ubifs_err(c, "on-flash format version %d is not supported",
602 c->fmt_version);
603 err = -EINVAL;
604 goto out;
605 }
606
607 switch (sup->key_hash) {
608 case UBIFS_KEY_HASH_R5:
609 c->key_hash = key_r5_hash;
610 c->key_hash_type = UBIFS_KEY_HASH_R5;
611 break;
612
613 case UBIFS_KEY_HASH_TEST:
614 c->key_hash = key_test_hash;
615 c->key_hash_type = UBIFS_KEY_HASH_TEST;
616 break;
617 };
618
619 c->key_fmt = sup->key_fmt;
620
621 switch (c->key_fmt) {
622 case UBIFS_SIMPLE_KEY_FMT:
623 c->key_len = UBIFS_SK_LEN;
624 break;
625 default:
626 ubifs_err(c, "unsupported key format");
627 err = -EINVAL;
628 goto out;
629 }
630
631 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
632 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
633 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
634 c->log_lebs = le32_to_cpu(sup->log_lebs);
635 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
636 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
637 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
638 c->fanout = le32_to_cpu(sup->fanout);
639 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
640 c->rp_size = le64_to_cpu(sup->rp_size);
641 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
642 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
643 sup_flags = le32_to_cpu(sup->flags);
644 if (!c->mount_opts.override_compr)
645 c->default_compr = le16_to_cpu(sup->default_compr);
646
647 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
648 memcpy(&c->uuid, &sup->uuid, 16);
649 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
650 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
651 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH);
652 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION);
653
654 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) {
655 ubifs_err(c, "Unknown feature flags found: %#x",
656 sup_flags & ~UBIFS_FLG_MASK);
657 err = -EINVAL;
658 goto out;
659 }
660
661 #ifndef CONFIG_UBIFS_FS_ENCRYPTION
662 if (c->encrypted) {
663 ubifs_err(c, "file system contains encrypted files but UBIFS"
664 " was built without crypto support.");
665 err = -EINVAL;
666 goto out;
667 }
668 #endif
669
670 /* Automatically increase file system size to the maximum size */
671 c->old_leb_cnt = c->leb_cnt;
672 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
673 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
674 if (c->ro_mount)
675 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
676 c->old_leb_cnt, c->leb_cnt);
677 else {
678 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
679 c->old_leb_cnt, c->leb_cnt);
680 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
681 err = ubifs_write_sb_node(c, sup);
682 if (err)
683 goto out;
684 c->old_leb_cnt = c->leb_cnt;
685 }
686 }
687
688 c->log_bytes = (long long)c->log_lebs * c->leb_size;
689 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
690 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
691 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
692 c->orph_first = c->lpt_last + 1;
693 c->orph_last = c->orph_first + c->orph_lebs - 1;
694 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
695 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
696 c->main_first = c->leb_cnt - c->main_lebs;
697
698 err = validate_sb(c, sup);
699 out:
700 kfree(sup);
701 return err;
702 }
703
704 /**
705 * fixup_leb - fixup/unmap an LEB containing free space.
706 * @c: UBIFS file-system description object
707 * @lnum: the LEB number to fix up
708 * @len: number of used bytes in LEB (starting at offset 0)
709 *
710 * This function reads the contents of the given LEB number @lnum, then fixes
711 * it up, so that empty min. I/O units in the end of LEB are actually erased on
712 * flash (rather than being just all-0xff real data). If the LEB is completely
713 * empty, it is simply unmapped.
714 */
fixup_leb(struct ubifs_info * c,int lnum,int len)715 static int fixup_leb(struct ubifs_info *c, int lnum, int len)
716 {
717 int err;
718
719 ubifs_assert(c, len >= 0);
720 ubifs_assert(c, len % c->min_io_size == 0);
721 ubifs_assert(c, len < c->leb_size);
722
723 if (len == 0) {
724 dbg_mnt("unmap empty LEB %d", lnum);
725 return ubifs_leb_unmap(c, lnum);
726 }
727
728 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
729 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
730 if (err)
731 return err;
732
733 return ubifs_leb_change(c, lnum, c->sbuf, len);
734 }
735
736 /**
737 * fixup_free_space - find & remap all LEBs containing free space.
738 * @c: UBIFS file-system description object
739 *
740 * This function walks through all LEBs in the filesystem and fiexes up those
741 * containing free/empty space.
742 */
fixup_free_space(struct ubifs_info * c)743 static int fixup_free_space(struct ubifs_info *c)
744 {
745 int lnum, err = 0;
746 struct ubifs_lprops *lprops;
747
748 ubifs_get_lprops(c);
749
750 /* Fixup LEBs in the master area */
751 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
752 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
753 if (err)
754 goto out;
755 }
756
757 /* Unmap unused log LEBs */
758 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
759 while (lnum != c->ltail_lnum) {
760 err = fixup_leb(c, lnum, 0);
761 if (err)
762 goto out;
763 lnum = ubifs_next_log_lnum(c, lnum);
764 }
765
766 /*
767 * Fixup the log head which contains the only a CS node at the
768 * beginning.
769 */
770 err = fixup_leb(c, c->lhead_lnum,
771 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
772 if (err)
773 goto out;
774
775 /* Fixup LEBs in the LPT area */
776 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
777 int free = c->ltab[lnum - c->lpt_first].free;
778
779 if (free > 0) {
780 err = fixup_leb(c, lnum, c->leb_size - free);
781 if (err)
782 goto out;
783 }
784 }
785
786 /* Unmap LEBs in the orphans area */
787 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
788 err = fixup_leb(c, lnum, 0);
789 if (err)
790 goto out;
791 }
792
793 /* Fixup LEBs in the main area */
794 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
795 lprops = ubifs_lpt_lookup(c, lnum);
796 if (IS_ERR(lprops)) {
797 err = PTR_ERR(lprops);
798 goto out;
799 }
800
801 if (lprops->free > 0) {
802 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
803 if (err)
804 goto out;
805 }
806 }
807
808 out:
809 ubifs_release_lprops(c);
810 return err;
811 }
812
813 /**
814 * ubifs_fixup_free_space - find & fix all LEBs with free space.
815 * @c: UBIFS file-system description object
816 *
817 * This function fixes up LEBs containing free space on first mount, if the
818 * appropriate flag was set when the FS was created. Each LEB with one or more
819 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
820 * the free space is actually erased. E.g., this is necessary for some NAND
821 * chips, since the free space may have been programmed like real "0xff" data
822 * (generating a non-0xff ECC), causing future writes to the not-really-erased
823 * NAND pages to behave badly. After the space is fixed up, the superblock flag
824 * is cleared, so that this is skipped for all future mounts.
825 */
ubifs_fixup_free_space(struct ubifs_info * c)826 int ubifs_fixup_free_space(struct ubifs_info *c)
827 {
828 int err;
829 struct ubifs_sb_node *sup;
830
831 ubifs_assert(c, c->space_fixup);
832 ubifs_assert(c, !c->ro_mount);
833
834 ubifs_msg(c, "start fixing up free space");
835
836 err = fixup_free_space(c);
837 if (err)
838 return err;
839
840 sup = ubifs_read_sb_node(c);
841 if (IS_ERR(sup))
842 return PTR_ERR(sup);
843
844 /* Free-space fixup is no longer required */
845 c->space_fixup = 0;
846 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
847
848 err = ubifs_write_sb_node(c, sup);
849 kfree(sup);
850 if (err)
851 return err;
852
853 ubifs_msg(c, "free space fixup complete");
854 return err;
855 }
856
ubifs_enable_encryption(struct ubifs_info * c)857 int ubifs_enable_encryption(struct ubifs_info *c)
858 {
859 int err;
860 struct ubifs_sb_node *sup;
861
862 if (c->encrypted)
863 return 0;
864
865 if (c->ro_mount || c->ro_media)
866 return -EROFS;
867
868 if (c->fmt_version < 5) {
869 ubifs_err(c, "on-flash format version 5 is needed for encryption");
870 return -EINVAL;
871 }
872
873 sup = ubifs_read_sb_node(c);
874 if (IS_ERR(sup))
875 return PTR_ERR(sup);
876
877 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION);
878
879 err = ubifs_write_sb_node(c, sup);
880 if (!err)
881 c->encrypted = 1;
882 kfree(sup);
883
884 return err;
885 }
886