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