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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation.
6 *
7 * Authors: Artem Bityutskiy (Битюцкий Артём)
8 * Adrian Hunter
9 */
10
11/*
12 * This file implements UBIFS superblock. The superblock is stored at the first
13 * LEB of the volume and is never changed by UBIFS. Only user-space tools may
14 * change it. The superblock node mostly contains geometry information.
15 */
16
17#include "ubifs.h"
18#include <linux/slab.h>
19#include <linux/math64.h>
20#include <linux/uuid.h>
21
22/*
23 * Default journal size in logical eraseblocks as a percent of total
24 * flash size.
25 */
26#define DEFAULT_JNL_PERCENT 5
27
28/* Default maximum journal size in bytes */
29#define DEFAULT_MAX_JNL (32*1024*1024)
30
31/* Default indexing tree fanout */
32#define DEFAULT_FANOUT 8
33
34/* Default number of data journal heads */
35#define DEFAULT_JHEADS_CNT 1
36
37/* Default positions of different LEBs in the main area */
38#define DEFAULT_IDX_LEB 0
39#define DEFAULT_DATA_LEB 1
40#define DEFAULT_GC_LEB 2
41
42/* Default number of LEB numbers in LPT's save table */
43#define DEFAULT_LSAVE_CNT 256
44
45/* Default reserved pool size as a percent of maximum free space */
46#define DEFAULT_RP_PERCENT 5
47
48/* The default maximum size of reserved pool in bytes */
49#define DEFAULT_MAX_RP_SIZE (5*1024*1024)
50
51/* Default time granularity in nanoseconds */
52#define DEFAULT_TIME_GRAN 1000000000
53
54static int get_default_compressor(struct ubifs_info *c)
55{
56 if (ubifs_compr_present(c, UBIFS_COMPR_LZO))
57 return UBIFS_COMPR_LZO;
58
59 if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB))
60 return UBIFS_COMPR_ZLIB;
61
62 return UBIFS_COMPR_NONE;
63}
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 */
72static 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;
84 int idx_node_size;
85 long long tmp64, main_bytes;
86 __le64 tmp_le64;
87 __le32 tmp_le32;
88 struct timespec64 ts;
89 u8 hash[UBIFS_HASH_ARR_SZ];
90 u8 hash_lpt[UBIFS_HASH_ARR_SZ];
91
92 /* Some functions called from here depend on the @c->key_len filed */
93 c->key_len = UBIFS_SK_LEN;
94
95 /*
96 * First of all, we have to calculate default file-system geometry -
97 * log size, journal size, etc.
98 */
99 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
100 /* We can first multiply then divide and have no overflow */
101 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
102 else
103 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
104
105 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
106 jnl_lebs = UBIFS_MIN_JNL_LEBS;
107 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
108 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
109
110 /*
111 * The log should be large enough to fit reference nodes for all bud
112 * LEBs. Because buds do not have to start from the beginning of LEBs
113 * (half of the LEB may contain committed data), the log should
114 * generally be larger, make it twice as large.
115 */
116 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
117 log_lebs = tmp / c->leb_size;
118 /* Plus one LEB reserved for commit */
119 log_lebs += 1;
120 if (c->leb_cnt - min_leb_cnt > 8) {
121 /* And some extra space to allow writes while committing */
122 log_lebs += 1;
123 min_leb_cnt += 1;
124 }
125
126 max_buds = jnl_lebs - log_lebs;
127 if (max_buds < UBIFS_MIN_BUD_LEBS)
128 max_buds = UBIFS_MIN_BUD_LEBS;
129
130 /*
131 * Orphan nodes are stored in a separate area. One node can store a lot
132 * of orphan inode numbers, but when new orphan comes we just add a new
133 * orphan node. At some point the nodes are consolidated into one
134 * orphan node.
135 */
136 orph_lebs = UBIFS_MIN_ORPH_LEBS;
137 if (c->leb_cnt - min_leb_cnt > 1)
138 /*
139 * For debugging purposes it is better to have at least 2
140 * orphan LEBs, because the orphan subsystem would need to do
141 * consolidations and would be stressed more.
142 */
143 orph_lebs += 1;
144
145 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
146 main_lebs -= orph_lebs;
147
148 lpt_first = UBIFS_LOG_LNUM + log_lebs;
149 c->lsave_cnt = DEFAULT_LSAVE_CNT;
150 c->max_leb_cnt = c->leb_cnt;
151 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
152 &big_lpt, hash_lpt);
153 if (err)
154 return err;
155
156 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
157 lpt_first + lpt_lebs - 1);
158
159 main_first = c->leb_cnt - main_lebs;
160
161 sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL);
162 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
163 idx_node_size = ubifs_idx_node_sz(c, 1);
164 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
165 ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL);
166 cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL);
167
168 if (!sup || !mst || !idx || !ino || !cs) {
169 err = -ENOMEM;
170 goto out;
171 }
172
173 /* Create default superblock */
174
175 tmp64 = (long long)max_buds * c->leb_size;
176 if (big_lpt)
177 sup_flags |= UBIFS_FLG_BIGLPT;
178 sup_flags |= UBIFS_FLG_DOUBLE_HASH;
179
180 if (ubifs_authenticated(c)) {
181 sup_flags |= UBIFS_FLG_AUTHENTICATION;
182 sup->hash_algo = cpu_to_le16(c->auth_hash_algo);
183 err = ubifs_hmac_wkm(c, sup->hmac_wkm);
184 if (err)
185 goto out;
186 } else {
187 sup->hash_algo = 0xffff;
188 }
189
190 sup->ch.node_type = UBIFS_SB_NODE;
191 sup->key_hash = UBIFS_KEY_HASH_R5;
192 sup->flags = cpu_to_le32(sup_flags);
193 sup->min_io_size = cpu_to_le32(c->min_io_size);
194 sup->leb_size = cpu_to_le32(c->leb_size);
195 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
196 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
197 sup->max_bud_bytes = cpu_to_le64(tmp64);
198 sup->log_lebs = cpu_to_le32(log_lebs);
199 sup->lpt_lebs = cpu_to_le32(lpt_lebs);
200 sup->orph_lebs = cpu_to_le32(orph_lebs);
201 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
202 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
203 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
204 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
205 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
206 if (c->mount_opts.override_compr)
207 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
208 else
209 sup->default_compr = cpu_to_le16(get_default_compressor(c));
210
211 generate_random_uuid(sup->uuid);
212
213 main_bytes = (long long)main_lebs * c->leb_size;
214 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
215 if (tmp64 > DEFAULT_MAX_RP_SIZE)
216 tmp64 = DEFAULT_MAX_RP_SIZE;
217 sup->rp_size = cpu_to_le64(tmp64);
218 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
219
220 dbg_gen("default superblock created at LEB 0:0");
221
222 /* Create default master node */
223
224 mst->ch.node_type = UBIFS_MST_NODE;
225 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
226 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
227 mst->cmt_no = 0;
228 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
229 mst->root_offs = 0;
230 tmp = ubifs_idx_node_sz(c, 1);
231 mst->root_len = cpu_to_le32(tmp);
232 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
233 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
234 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
235 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
236 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
237 mst->lpt_offs = cpu_to_le32(c->lpt_offs);
238 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
239 mst->nhead_offs = cpu_to_le32(c->nhead_offs);
240 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
241 mst->ltab_offs = cpu_to_le32(c->ltab_offs);
242 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
243 mst->lsave_offs = cpu_to_le32(c->lsave_offs);
244 mst->lscan_lnum = cpu_to_le32(main_first);
245 mst->empty_lebs = cpu_to_le32(main_lebs - 2);
246 mst->idx_lebs = cpu_to_le32(1);
247 mst->leb_cnt = cpu_to_le32(c->leb_cnt);
248 ubifs_copy_hash(c, hash_lpt, mst->hash_lpt);
249
250 /* Calculate lprops statistics */
251 tmp64 = main_bytes;
252 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
253 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
254 mst->total_free = cpu_to_le64(tmp64);
255
256 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
257 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
258 UBIFS_INO_NODE_SZ;
259 tmp64 += ino_waste;
260 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
261 mst->total_dirty = cpu_to_le64(tmp64);
262
263 /* The indexing LEB does not contribute to dark space */
264 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
265 mst->total_dark = cpu_to_le64(tmp64);
266
267 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
268
269 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
270
271 /* Create the root indexing node */
272
273 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
274 c->key_hash = key_r5_hash;
275
276 idx->ch.node_type = UBIFS_IDX_NODE;
277 idx->child_cnt = cpu_to_le16(1);
278 ino_key_init(c, &key, UBIFS_ROOT_INO);
279 br = ubifs_idx_branch(c, idx, 0);
280 key_write_idx(c, &key, &br->key);
281 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
282 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
283
284 dbg_gen("default root indexing node created LEB %d:0",
285 main_first + DEFAULT_IDX_LEB);
286
287 /* Create default root inode */
288
289 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
290 ino->ch.node_type = UBIFS_INO_NODE;
291 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
292 ino->nlink = cpu_to_le32(2);
293
294 ktime_get_real_ts64(&ts);
295 ts = timespec64_trunc(ts, DEFAULT_TIME_GRAN);
296 tmp_le64 = cpu_to_le64(ts.tv_sec);
297 ino->atime_sec = tmp_le64;
298 ino->ctime_sec = tmp_le64;
299 ino->mtime_sec = tmp_le64;
300 tmp_le32 = cpu_to_le32(ts.tv_nsec);
301 ino->atime_nsec = tmp_le32;
302 ino->ctime_nsec = tmp_le32;
303 ino->mtime_nsec = tmp_le32;
304 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
305 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
306
307 /* Set compression enabled by default */
308 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
309
310 dbg_gen("root inode created at LEB %d:0",
311 main_first + DEFAULT_DATA_LEB);
312
313 /*
314 * The first node in the log has to be the commit start node. This is
315 * always the case during normal file-system operation. Write a fake
316 * commit start node to the log.
317 */
318
319 cs->ch.node_type = UBIFS_CS_NODE;
320
321 err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0,
322 offsetof(struct ubifs_sb_node, hmac));
323 if (err)
324 goto out;
325
326 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
327 main_first + DEFAULT_DATA_LEB, 0);
328 if (err)
329 goto out;
330
331 ubifs_node_calc_hash(c, ino, hash);
332 ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br));
333
334 err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0);
335 if (err)
336 goto out;
337
338 ubifs_node_calc_hash(c, idx, hash);
339 ubifs_copy_hash(c, hash, mst->hash_root_idx);
340
341 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
342 offsetof(struct ubifs_mst_node, hmac));
343 if (err)
344 goto out;
345
346 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
347 0, offsetof(struct ubifs_mst_node, hmac));
348 if (err)
349 goto out;
350
351 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
352 if (err)
353 goto out;
354
355 ubifs_msg(c, "default file-system created");
356
357 err = 0;
358out:
359 kfree(sup);
360 kfree(mst);
361 kfree(idx);
362 kfree(ino);
363 kfree(cs);
364
365 return err;
366}
367
368/**
369 * validate_sb - validate superblock node.
370 * @c: UBIFS file-system description object
371 * @sup: superblock node
372 *
373 * This function validates superblock node @sup. Since most of data was read
374 * from the superblock and stored in @c, the function validates fields in @c
375 * instead. Returns zero in case of success and %-EINVAL in case of validation
376 * failure.
377 */
378static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
379{
380 long long max_bytes;
381 int err = 1, min_leb_cnt;
382
383 if (!c->key_hash) {
384 err = 2;
385 goto failed;
386 }
387
388 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
389 err = 3;
390 goto failed;
391 }
392
393 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
394 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real",
395 le32_to_cpu(sup->min_io_size), c->min_io_size);
396 goto failed;
397 }
398
399 if (le32_to_cpu(sup->leb_size) != c->leb_size) {
400 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real",
401 le32_to_cpu(sup->leb_size), c->leb_size);
402 goto failed;
403 }
404
405 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
406 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
407 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
408 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
409 err = 4;
410 goto failed;
411 }
412
413 /*
414 * Calculate minimum allowed amount of main area LEBs. This is very
415 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
416 * have just read from the superblock.
417 */
418 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
419 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
420
421 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
422 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
423 c->leb_cnt, c->vi.size, min_leb_cnt);
424 goto failed;
425 }
426
427 if (c->max_leb_cnt < c->leb_cnt) {
428 ubifs_err(c, "max. LEB count %d less than LEB count %d",
429 c->max_leb_cnt, c->leb_cnt);
430 goto failed;
431 }
432
433 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
434 ubifs_err(c, "too few main LEBs count %d, must be at least %d",
435 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
436 goto failed;
437 }
438
439 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
440 if (c->max_bud_bytes < max_bytes) {
441 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes",
442 c->max_bud_bytes, max_bytes);
443 goto failed;
444 }
445
446 max_bytes = (long long)c->leb_size * c->main_lebs;
447 if (c->max_bud_bytes > max_bytes) {
448 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area",
449 c->max_bud_bytes, max_bytes);
450 goto failed;
451 }
452
453 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
454 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
455 err = 9;
456 goto failed;
457 }
458
459 if (c->fanout < UBIFS_MIN_FANOUT ||
460 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
461 err = 10;
462 goto failed;
463 }
464
465 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
466 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
467 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
468 err = 11;
469 goto failed;
470 }
471
472 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
473 c->orph_lebs + c->main_lebs != c->leb_cnt) {
474 err = 12;
475 goto failed;
476 }
477
478 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
479 err = 13;
480 goto failed;
481 }
482
483 if (c->rp_size < 0 || max_bytes < c->rp_size) {
484 err = 14;
485 goto failed;
486 }
487
488 if (le32_to_cpu(sup->time_gran) > 1000000000 ||
489 le32_to_cpu(sup->time_gran) < 1) {
490 err = 15;
491 goto failed;
492 }
493
494 if (!c->double_hash && c->fmt_version >= 5) {
495 err = 16;
496 goto failed;
497 }
498
499 if (c->encrypted && c->fmt_version < 5) {
500 err = 17;
501 goto failed;
502 }
503
504 return 0;
505
506failed:
507 ubifs_err(c, "bad superblock, error %d", err);
508 ubifs_dump_node(c, sup);
509 return -EINVAL;
510}
511
512/**
513 * ubifs_read_sb_node - read superblock node.
514 * @c: UBIFS file-system description object
515 *
516 * This function returns a pointer to the superblock node or a negative error
517 * code. Note, the user of this function is responsible of kfree()'ing the
518 * returned superblock buffer.
519 */
520static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
521{
522 struct ubifs_sb_node *sup;
523 int err;
524
525 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
526 if (!sup)
527 return ERR_PTR(-ENOMEM);
528
529 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
530 UBIFS_SB_LNUM, 0);
531 if (err) {
532 kfree(sup);
533 return ERR_PTR(err);
534 }
535
536 return sup;
537}
538
539static int authenticate_sb_node(struct ubifs_info *c,
540 const struct ubifs_sb_node *sup)
541{
542 unsigned int sup_flags = le32_to_cpu(sup->flags);
543 u8 hmac_wkm[UBIFS_HMAC_ARR_SZ];
544 int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION);
545 int hash_algo;
546 int err;
547
548 if (c->authenticated && !authenticated) {
549 ubifs_err(c, "authenticated FS forced, but found FS without authentication");
550 return -EINVAL;
551 }
552
553 if (!c->authenticated && authenticated) {
554 ubifs_err(c, "authenticated FS found, but no key given");
555 return -EINVAL;
556 }
557
558 ubifs_msg(c, "Mounting in %sauthenticated mode",
559 c->authenticated ? "" : "un");
560
561 if (!c->authenticated)
562 return 0;
563
564 if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION))
565 return -EOPNOTSUPP;
566
567 hash_algo = le16_to_cpu(sup->hash_algo);
568 if (hash_algo >= HASH_ALGO__LAST) {
569 ubifs_err(c, "superblock uses unknown hash algo %d",
570 hash_algo);
571 return -EINVAL;
572 }
573
574 if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) {
575 ubifs_err(c, "This filesystem uses %s for hashing,"
576 " but %s is specified", hash_algo_name[hash_algo],
577 c->auth_hash_name);
578 return -EINVAL;
579 }
580
581 /*
582 * The super block node can either be authenticated by a HMAC or
583 * by a signature in a ubifs_sig_node directly following the
584 * super block node to support offline image creation.
585 */
586 if (ubifs_hmac_zero(c, sup->hmac)) {
587 err = ubifs_sb_verify_signature(c, sup);
588 } else {
589 err = ubifs_hmac_wkm(c, hmac_wkm);
590 if (err)
591 return err;
592 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) {
593 ubifs_err(c, "provided key does not fit");
594 return -ENOKEY;
595 }
596 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup),
597 offsetof(struct ubifs_sb_node,
598 hmac));
599 }
600
601 if (err)
602 ubifs_err(c, "Failed to authenticate superblock: %d", err);
603
604 return err;
605}
606
607/**
608 * ubifs_write_sb_node - write superblock node.
609 * @c: UBIFS file-system description object
610 * @sup: superblock node read with 'ubifs_read_sb_node()'
611 *
612 * This function returns %0 on success and a negative error code on failure.
613 */
614int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
615{
616 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
617 int err;
618
619 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ,
620 offsetof(struct ubifs_sb_node, hmac), 1);
621 if (err)
622 return err;
623
624 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);
625}
626
627/**
628 * ubifs_read_superblock - read superblock.
629 * @c: UBIFS file-system description object
630 *
631 * This function finds, reads and checks the superblock. If an empty UBI volume
632 * is being mounted, this function creates default superblock. Returns zero in
633 * case of success, and a negative error code in case of failure.
634 */
635int ubifs_read_superblock(struct ubifs_info *c)
636{
637 int err, sup_flags;
638 struct ubifs_sb_node *sup;
639
640 if (c->empty) {
641 err = create_default_filesystem(c);
642 if (err)
643 return err;
644 }
645
646 sup = ubifs_read_sb_node(c);
647 if (IS_ERR(sup))
648 return PTR_ERR(sup);
649
650 c->sup_node = sup;
651
652 c->fmt_version = le32_to_cpu(sup->fmt_version);
653 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
654
655 /*
656 * The software supports all previous versions but not future versions,
657 * due to the unavailability of time-travelling equipment.
658 */
659 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
660 ubifs_assert(c, !c->ro_media || c->ro_mount);
661 if (!c->ro_mount ||
662 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
663 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
664 c->fmt_version, c->ro_compat_version,
665 UBIFS_FORMAT_VERSION,
666 UBIFS_RO_COMPAT_VERSION);
667 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
668 ubifs_msg(c, "only R/O mounting is possible");
669 err = -EROFS;
670 } else
671 err = -EINVAL;
672 goto out;
673 }
674
675 /*
676 * The FS is mounted R/O, and the media format is
677 * R/O-compatible with the UBIFS implementation, so we can
678 * mount.
679 */
680 c->rw_incompat = 1;
681 }
682
683 if (c->fmt_version < 3) {
684 ubifs_err(c, "on-flash format version %d is not supported",
685 c->fmt_version);
686 err = -EINVAL;
687 goto out;
688 }
689
690 switch (sup->key_hash) {
691 case UBIFS_KEY_HASH_R5:
692 c->key_hash = key_r5_hash;
693 c->key_hash_type = UBIFS_KEY_HASH_R5;
694 break;
695
696 case UBIFS_KEY_HASH_TEST:
697 c->key_hash = key_test_hash;
698 c->key_hash_type = UBIFS_KEY_HASH_TEST;
699 break;
700 }
701
702 c->key_fmt = sup->key_fmt;
703
704 switch (c->key_fmt) {
705 case UBIFS_SIMPLE_KEY_FMT:
706 c->key_len = UBIFS_SK_LEN;
707 break;
708 default:
709 ubifs_err(c, "unsupported key format");
710 err = -EINVAL;
711 goto out;
712 }
713
714 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
715 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
716 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
717 c->log_lebs = le32_to_cpu(sup->log_lebs);
718 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
719 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
720 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
721 c->fanout = le32_to_cpu(sup->fanout);
722 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
723 c->rp_size = le64_to_cpu(sup->rp_size);
724 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
725 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
726 sup_flags = le32_to_cpu(sup->flags);
727 if (!c->mount_opts.override_compr)
728 c->default_compr = le16_to_cpu(sup->default_compr);
729
730 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
731 memcpy(&c->uuid, &sup->uuid, 16);
732 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
733 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
734 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH);
735 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION);
736
737 err = authenticate_sb_node(c, sup);
738 if (err)
739 goto out;
740
741 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) {
742 ubifs_err(c, "Unknown feature flags found: %#x",
743 sup_flags & ~UBIFS_FLG_MASK);
744 err = -EINVAL;
745 goto out;
746 }
747
748 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) {
749 ubifs_err(c, "file system contains encrypted files but UBIFS"
750 " was built without crypto support.");
751 err = -EINVAL;
752 goto out;
753 }
754
755 /* Automatically increase file system size to the maximum size */
756 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
757 int old_leb_cnt = c->leb_cnt;
758
759 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
760 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
761
762 c->superblock_need_write = 1;
763
764 dbg_mnt("Auto resizing from %d LEBs to %d LEBs",
765 old_leb_cnt, c->leb_cnt);
766 }
767
768 c->log_bytes = (long long)c->log_lebs * c->leb_size;
769 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
770 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
771 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
772 c->orph_first = c->lpt_last + 1;
773 c->orph_last = c->orph_first + c->orph_lebs - 1;
774 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
775 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
776 c->main_first = c->leb_cnt - c->main_lebs;
777
778 err = validate_sb(c, sup);
779out:
780 return err;
781}
782
783/**
784 * fixup_leb - fixup/unmap an LEB containing free space.
785 * @c: UBIFS file-system description object
786 * @lnum: the LEB number to fix up
787 * @len: number of used bytes in LEB (starting at offset 0)
788 *
789 * This function reads the contents of the given LEB number @lnum, then fixes
790 * it up, so that empty min. I/O units in the end of LEB are actually erased on
791 * flash (rather than being just all-0xff real data). If the LEB is completely
792 * empty, it is simply unmapped.
793 */
794static int fixup_leb(struct ubifs_info *c, int lnum, int len)
795{
796 int err;
797
798 ubifs_assert(c, len >= 0);
799 ubifs_assert(c, len % c->min_io_size == 0);
800 ubifs_assert(c, len < c->leb_size);
801
802 if (len == 0) {
803 dbg_mnt("unmap empty LEB %d", lnum);
804 return ubifs_leb_unmap(c, lnum);
805 }
806
807 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
808 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
809 if (err)
810 return err;
811
812 return ubifs_leb_change(c, lnum, c->sbuf, len);
813}
814
815/**
816 * fixup_free_space - find & remap all LEBs containing free space.
817 * @c: UBIFS file-system description object
818 *
819 * This function walks through all LEBs in the filesystem and fiexes up those
820 * containing free/empty space.
821 */
822static int fixup_free_space(struct ubifs_info *c)
823{
824 int lnum, err = 0;
825 struct ubifs_lprops *lprops;
826
827 ubifs_get_lprops(c);
828
829 /* Fixup LEBs in the master area */
830 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
831 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
832 if (err)
833 goto out;
834 }
835
836 /* Unmap unused log LEBs */
837 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
838 while (lnum != c->ltail_lnum) {
839 err = fixup_leb(c, lnum, 0);
840 if (err)
841 goto out;
842 lnum = ubifs_next_log_lnum(c, lnum);
843 }
844
845 /*
846 * Fixup the log head which contains the only a CS node at the
847 * beginning.
848 */
849 err = fixup_leb(c, c->lhead_lnum,
850 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
851 if (err)
852 goto out;
853
854 /* Fixup LEBs in the LPT area */
855 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
856 int free = c->ltab[lnum - c->lpt_first].free;
857
858 if (free > 0) {
859 err = fixup_leb(c, lnum, c->leb_size - free);
860 if (err)
861 goto out;
862 }
863 }
864
865 /* Unmap LEBs in the orphans area */
866 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
867 err = fixup_leb(c, lnum, 0);
868 if (err)
869 goto out;
870 }
871
872 /* Fixup LEBs in the main area */
873 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
874 lprops = ubifs_lpt_lookup(c, lnum);
875 if (IS_ERR(lprops)) {
876 err = PTR_ERR(lprops);
877 goto out;
878 }
879
880 if (lprops->free > 0) {
881 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
882 if (err)
883 goto out;
884 }
885 }
886
887out:
888 ubifs_release_lprops(c);
889 return err;
890}
891
892/**
893 * ubifs_fixup_free_space - find & fix all LEBs with free space.
894 * @c: UBIFS file-system description object
895 *
896 * This function fixes up LEBs containing free space on first mount, if the
897 * appropriate flag was set when the FS was created. Each LEB with one or more
898 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
899 * the free space is actually erased. E.g., this is necessary for some NAND
900 * chips, since the free space may have been programmed like real "0xff" data
901 * (generating a non-0xff ECC), causing future writes to the not-really-erased
902 * NAND pages to behave badly. After the space is fixed up, the superblock flag
903 * is cleared, so that this is skipped for all future mounts.
904 */
905int ubifs_fixup_free_space(struct ubifs_info *c)
906{
907 int err;
908 struct ubifs_sb_node *sup = c->sup_node;
909
910 ubifs_assert(c, c->space_fixup);
911 ubifs_assert(c, !c->ro_mount);
912
913 ubifs_msg(c, "start fixing up free space");
914
915 err = fixup_free_space(c);
916 if (err)
917 return err;
918
919 /* Free-space fixup is no longer required */
920 c->space_fixup = 0;
921 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
922
923 c->superblock_need_write = 1;
924
925 ubifs_msg(c, "free space fixup complete");
926 return err;
927}
928
929int ubifs_enable_encryption(struct ubifs_info *c)
930{
931 int err;
932 struct ubifs_sb_node *sup = c->sup_node;
933
934 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION))
935 return -EOPNOTSUPP;
936
937 if (c->encrypted)
938 return 0;
939
940 if (c->ro_mount || c->ro_media)
941 return -EROFS;
942
943 if (c->fmt_version < 5) {
944 ubifs_err(c, "on-flash format version 5 is needed for encryption");
945 return -EINVAL;
946 }
947
948 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION);
949
950 err = ubifs_write_sb_node(c, sup);
951 if (!err)
952 c->encrypted = 1;
953
954 return err;
955}
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/random.h>
32#include <linux/math64.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 */
73static 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
88 /* Some functions called from here depend on the @c->key_len filed */
89 c->key_len = UBIFS_SK_LEN;
90
91 /*
92 * First of all, we have to calculate default file-system geometry -
93 * log size, journal size, etc.
94 */
95 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
96 /* We can first multiply then divide and have no overflow */
97 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
98 else
99 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
100
101 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
102 jnl_lebs = UBIFS_MIN_JNL_LEBS;
103 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
104 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
105
106 /*
107 * The log should be large enough to fit reference nodes for all bud
108 * LEBs. Because buds do not have to start from the beginning of LEBs
109 * (half of the LEB may contain committed data), the log should
110 * generally be larger, make it twice as large.
111 */
112 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
113 log_lebs = tmp / c->leb_size;
114 /* Plus one LEB reserved for commit */
115 log_lebs += 1;
116 if (c->leb_cnt - min_leb_cnt > 8) {
117 /* And some extra space to allow writes while committing */
118 log_lebs += 1;
119 min_leb_cnt += 1;
120 }
121
122 max_buds = jnl_lebs - log_lebs;
123 if (max_buds < UBIFS_MIN_BUD_LEBS)
124 max_buds = UBIFS_MIN_BUD_LEBS;
125
126 /*
127 * Orphan nodes are stored in a separate area. One node can store a lot
128 * of orphan inode numbers, but when new orphan comes we just add a new
129 * orphan node. At some point the nodes are consolidated into one
130 * orphan node.
131 */
132 orph_lebs = UBIFS_MIN_ORPH_LEBS;
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
141 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
142 main_lebs -= orph_lebs;
143
144 lpt_first = UBIFS_LOG_LNUM + log_lebs;
145 c->lsave_cnt = DEFAULT_LSAVE_CNT;
146 c->max_leb_cnt = c->leb_cnt;
147 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
148 &big_lpt);
149 if (err)
150 return err;
151
152 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
153 lpt_first + lpt_lebs - 1);
154
155 main_first = c->leb_cnt - main_lebs;
156
157 /* Create default superblock */
158 tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
159 sup = kzalloc(tmp, GFP_KERNEL);
160 if (!sup)
161 return -ENOMEM;
162
163 tmp64 = (long long)max_buds * c->leb_size;
164 if (big_lpt)
165 sup_flags |= UBIFS_FLG_BIGLPT;
166
167 sup->ch.node_type = UBIFS_SB_NODE;
168 sup->key_hash = UBIFS_KEY_HASH_R5;
169 sup->flags = cpu_to_le32(sup_flags);
170 sup->min_io_size = cpu_to_le32(c->min_io_size);
171 sup->leb_size = cpu_to_le32(c->leb_size);
172 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
173 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
174 sup->max_bud_bytes = cpu_to_le64(tmp64);
175 sup->log_lebs = cpu_to_le32(log_lebs);
176 sup->lpt_lebs = cpu_to_le32(lpt_lebs);
177 sup->orph_lebs = cpu_to_le32(orph_lebs);
178 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
179 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
180 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
181 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
182 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
183 if (c->mount_opts.override_compr)
184 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
185 else
186 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
187
188 generate_random_uuid(sup->uuid);
189
190 main_bytes = (long long)main_lebs * c->leb_size;
191 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
192 if (tmp64 > DEFAULT_MAX_RP_SIZE)
193 tmp64 = DEFAULT_MAX_RP_SIZE;
194 sup->rp_size = cpu_to_le64(tmp64);
195 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
196
197 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0);
198 kfree(sup);
199 if (err)
200 return err;
201
202 dbg_gen("default superblock created at LEB 0:0");
203
204 /* Create default master node */
205 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
206 if (!mst)
207 return -ENOMEM;
208
209 mst->ch.node_type = UBIFS_MST_NODE;
210 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
211 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
212 mst->cmt_no = 0;
213 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
214 mst->root_offs = 0;
215 tmp = ubifs_idx_node_sz(c, 1);
216 mst->root_len = cpu_to_le32(tmp);
217 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
218 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
219 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
220 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
221 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
222 mst->lpt_offs = cpu_to_le32(c->lpt_offs);
223 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
224 mst->nhead_offs = cpu_to_le32(c->nhead_offs);
225 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
226 mst->ltab_offs = cpu_to_le32(c->ltab_offs);
227 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
228 mst->lsave_offs = cpu_to_le32(c->lsave_offs);
229 mst->lscan_lnum = cpu_to_le32(main_first);
230 mst->empty_lebs = cpu_to_le32(main_lebs - 2);
231 mst->idx_lebs = cpu_to_le32(1);
232 mst->leb_cnt = cpu_to_le32(c->leb_cnt);
233
234 /* Calculate lprops statistics */
235 tmp64 = main_bytes;
236 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
237 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
238 mst->total_free = cpu_to_le64(tmp64);
239
240 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
241 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
242 UBIFS_INO_NODE_SZ;
243 tmp64 += ino_waste;
244 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
245 mst->total_dirty = cpu_to_le64(tmp64);
246
247 /* The indexing LEB does not contribute to dark space */
248 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
249 mst->total_dark = cpu_to_le64(tmp64);
250
251 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
252
253 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0);
254 if (err) {
255 kfree(mst);
256 return err;
257 }
258 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
259 0);
260 kfree(mst);
261 if (err)
262 return err;
263
264 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
265
266 /* Create the root indexing node */
267 tmp = ubifs_idx_node_sz(c, 1);
268 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
269 if (!idx)
270 return -ENOMEM;
271
272 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
273 c->key_hash = key_r5_hash;
274
275 idx->ch.node_type = UBIFS_IDX_NODE;
276 idx->child_cnt = cpu_to_le16(1);
277 ino_key_init(c, &key, UBIFS_ROOT_INO);
278 br = ubifs_idx_branch(c, idx, 0);
279 key_write_idx(c, &key, &br->key);
280 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
281 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
282 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0);
283 kfree(idx);
284 if (err)
285 return err;
286
287 dbg_gen("default root indexing node created LEB %d:0",
288 main_first + DEFAULT_IDX_LEB);
289
290 /* Create default root inode */
291 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
292 ino = kzalloc(tmp, GFP_KERNEL);
293 if (!ino)
294 return -ENOMEM;
295
296 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
297 ino->ch.node_type = UBIFS_INO_NODE;
298 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
299 ino->nlink = cpu_to_le32(2);
300 tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
301 ino->atime_sec = tmp_le64;
302 ino->ctime_sec = tmp_le64;
303 ino->mtime_sec = tmp_le64;
304 ino->atime_nsec = 0;
305 ino->ctime_nsec = 0;
306 ino->mtime_nsec = 0;
307 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
308 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
309
310 /* Set compression enabled by default */
311 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
312
313 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
314 main_first + DEFAULT_DATA_LEB, 0);
315 kfree(ino);
316 if (err)
317 return err;
318
319 dbg_gen("root inode created at LEB %d:0",
320 main_first + DEFAULT_DATA_LEB);
321
322 /*
323 * The first node in the log has to be the commit start node. This is
324 * always the case during normal file-system operation. Write a fake
325 * commit start node to the log.
326 */
327 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
328 cs = kzalloc(tmp, GFP_KERNEL);
329 if (!cs)
330 return -ENOMEM;
331
332 cs->ch.node_type = UBIFS_CS_NODE;
333 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
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 */
350static 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 ubifs_err("too few main LEBs count %d, must be at least %d",
408 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
409 goto failed;
410 }
411
412 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
413 if (c->max_bud_bytes < max_bytes) {
414 ubifs_err("too small journal (%lld bytes), must be at least "
415 "%lld bytes", c->max_bud_bytes, max_bytes);
416 goto failed;
417 }
418
419 max_bytes = (long long)c->leb_size * c->main_lebs;
420 if (c->max_bud_bytes > max_bytes) {
421 ubifs_err("too large journal size (%lld bytes), only %lld bytes"
422 "available in the main area",
423 c->max_bud_bytes, max_bytes);
424 goto failed;
425 }
426
427 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
428 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
429 err = 9;
430 goto failed;
431 }
432
433 if (c->fanout < UBIFS_MIN_FANOUT ||
434 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
435 err = 10;
436 goto failed;
437 }
438
439 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
440 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
441 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
442 err = 11;
443 goto failed;
444 }
445
446 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
447 c->orph_lebs + c->main_lebs != c->leb_cnt) {
448 err = 12;
449 goto failed;
450 }
451
452 if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
453 err = 13;
454 goto failed;
455 }
456
457 if (c->rp_size < 0 || max_bytes < c->rp_size) {
458 err = 14;
459 goto failed;
460 }
461
462 if (le32_to_cpu(sup->time_gran) > 1000000000 ||
463 le32_to_cpu(sup->time_gran) < 1) {
464 err = 15;
465 goto failed;
466 }
467
468 return 0;
469
470failed:
471 ubifs_err("bad superblock, error %d", err);
472 ubifs_dump_node(c, sup);
473 return -EINVAL;
474}
475
476/**
477 * ubifs_read_sb_node - read superblock node.
478 * @c: UBIFS file-system description object
479 *
480 * This function returns a pointer to the superblock node or a negative error
481 * code. Note, the user of this function is responsible of kfree()'ing the
482 * returned superblock buffer.
483 */
484struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
485{
486 struct ubifs_sb_node *sup;
487 int err;
488
489 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
490 if (!sup)
491 return ERR_PTR(-ENOMEM);
492
493 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
494 UBIFS_SB_LNUM, 0);
495 if (err) {
496 kfree(sup);
497 return ERR_PTR(err);
498 }
499
500 return sup;
501}
502
503/**
504 * ubifs_write_sb_node - write superblock node.
505 * @c: UBIFS file-system description object
506 * @sup: superblock node read with 'ubifs_read_sb_node()'
507 *
508 * This function returns %0 on success and a negative error code on failure.
509 */
510int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
511{
512 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
513
514 ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
515 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);
516}
517
518/**
519 * ubifs_read_superblock - read superblock.
520 * @c: UBIFS file-system description object
521 *
522 * This function finds, reads and checks the superblock. If an empty UBI volume
523 * is being mounted, this function creates default superblock. Returns zero in
524 * case of success, and a negative error code in case of failure.
525 */
526int ubifs_read_superblock(struct ubifs_info *c)
527{
528 int err, sup_flags;
529 struct ubifs_sb_node *sup;
530
531 if (c->empty) {
532 err = create_default_filesystem(c);
533 if (err)
534 return err;
535 }
536
537 sup = ubifs_read_sb_node(c);
538 if (IS_ERR(sup))
539 return PTR_ERR(sup);
540
541 c->fmt_version = le32_to_cpu(sup->fmt_version);
542 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
543
544 /*
545 * The software supports all previous versions but not future versions,
546 * due to the unavailability of time-travelling equipment.
547 */
548 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
549 ubifs_assert(!c->ro_media || c->ro_mount);
550 if (!c->ro_mount ||
551 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
552 ubifs_err("on-flash format version is w%d/r%d, but "
553 "software only supports up to version "
554 "w%d/r%d", c->fmt_version,
555 c->ro_compat_version, UBIFS_FORMAT_VERSION,
556 UBIFS_RO_COMPAT_VERSION);
557 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
558 ubifs_msg("only R/O mounting is possible");
559 err = -EROFS;
560 } else
561 err = -EINVAL;
562 goto out;
563 }
564
565 /*
566 * The FS is mounted R/O, and the media format is
567 * R/O-compatible with the UBIFS implementation, so we can
568 * mount.
569 */
570 c->rw_incompat = 1;
571 }
572
573 if (c->fmt_version < 3) {
574 ubifs_err("on-flash format version %d is not supported",
575 c->fmt_version);
576 err = -EINVAL;
577 goto out;
578 }
579
580 switch (sup->key_hash) {
581 case UBIFS_KEY_HASH_R5:
582 c->key_hash = key_r5_hash;
583 c->key_hash_type = UBIFS_KEY_HASH_R5;
584 break;
585
586 case UBIFS_KEY_HASH_TEST:
587 c->key_hash = key_test_hash;
588 c->key_hash_type = UBIFS_KEY_HASH_TEST;
589 break;
590 };
591
592 c->key_fmt = sup->key_fmt;
593
594 switch (c->key_fmt) {
595 case UBIFS_SIMPLE_KEY_FMT:
596 c->key_len = UBIFS_SK_LEN;
597 break;
598 default:
599 ubifs_err("unsupported key format");
600 err = -EINVAL;
601 goto out;
602 }
603
604 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
605 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
606 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
607 c->log_lebs = le32_to_cpu(sup->log_lebs);
608 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
609 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
610 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
611 c->fanout = le32_to_cpu(sup->fanout);
612 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
613 c->rp_size = le64_to_cpu(sup->rp_size);
614 c->rp_uid = le32_to_cpu(sup->rp_uid);
615 c->rp_gid = le32_to_cpu(sup->rp_gid);
616 sup_flags = le32_to_cpu(sup->flags);
617 if (!c->mount_opts.override_compr)
618 c->default_compr = le16_to_cpu(sup->default_compr);
619
620 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
621 memcpy(&c->uuid, &sup->uuid, 16);
622 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
623 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
624
625 /* Automatically increase file system size to the maximum size */
626 c->old_leb_cnt = c->leb_cnt;
627 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
628 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
629 if (c->ro_mount)
630 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
631 c->old_leb_cnt, c->leb_cnt);
632 else {
633 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
634 c->old_leb_cnt, c->leb_cnt);
635 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
636 err = ubifs_write_sb_node(c, sup);
637 if (err)
638 goto out;
639 c->old_leb_cnt = c->leb_cnt;
640 }
641 }
642
643 c->log_bytes = (long long)c->log_lebs * c->leb_size;
644 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
645 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
646 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
647 c->orph_first = c->lpt_last + 1;
648 c->orph_last = c->orph_first + c->orph_lebs - 1;
649 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
650 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
651 c->main_first = c->leb_cnt - c->main_lebs;
652
653 err = validate_sb(c, sup);
654out:
655 kfree(sup);
656 return err;
657}
658
659/**
660 * fixup_leb - fixup/unmap an LEB containing free space.
661 * @c: UBIFS file-system description object
662 * @lnum: the LEB number to fix up
663 * @len: number of used bytes in LEB (starting at offset 0)
664 *
665 * This function reads the contents of the given LEB number @lnum, then fixes
666 * it up, so that empty min. I/O units in the end of LEB are actually erased on
667 * flash (rather than being just all-0xff real data). If the LEB is completely
668 * empty, it is simply unmapped.
669 */
670static int fixup_leb(struct ubifs_info *c, int lnum, int len)
671{
672 int err;
673
674 ubifs_assert(len >= 0);
675 ubifs_assert(len % c->min_io_size == 0);
676 ubifs_assert(len < c->leb_size);
677
678 if (len == 0) {
679 dbg_mnt("unmap empty LEB %d", lnum);
680 return ubifs_leb_unmap(c, lnum);
681 }
682
683 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
684 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
685 if (err)
686 return err;
687
688 return ubifs_leb_change(c, lnum, c->sbuf, len);
689}
690
691/**
692 * fixup_free_space - find & remap all LEBs containing free space.
693 * @c: UBIFS file-system description object
694 *
695 * This function walks through all LEBs in the filesystem and fiexes up those
696 * containing free/empty space.
697 */
698static int fixup_free_space(struct ubifs_info *c)
699{
700 int lnum, err = 0;
701 struct ubifs_lprops *lprops;
702
703 ubifs_get_lprops(c);
704
705 /* Fixup LEBs in the master area */
706 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
707 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
708 if (err)
709 goto out;
710 }
711
712 /* Unmap unused log LEBs */
713 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
714 while (lnum != c->ltail_lnum) {
715 err = fixup_leb(c, lnum, 0);
716 if (err)
717 goto out;
718 lnum = ubifs_next_log_lnum(c, lnum);
719 }
720
721 /*
722 * Fixup the log head which contains the only a CS node at the
723 * beginning.
724 */
725 err = fixup_leb(c, c->lhead_lnum,
726 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
727 if (err)
728 goto out;
729
730 /* Fixup LEBs in the LPT area */
731 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
732 int free = c->ltab[lnum - c->lpt_first].free;
733
734 if (free > 0) {
735 err = fixup_leb(c, lnum, c->leb_size - free);
736 if (err)
737 goto out;
738 }
739 }
740
741 /* Unmap LEBs in the orphans area */
742 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
743 err = fixup_leb(c, lnum, 0);
744 if (err)
745 goto out;
746 }
747
748 /* Fixup LEBs in the main area */
749 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
750 lprops = ubifs_lpt_lookup(c, lnum);
751 if (IS_ERR(lprops)) {
752 err = PTR_ERR(lprops);
753 goto out;
754 }
755
756 if (lprops->free > 0) {
757 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
758 if (err)
759 goto out;
760 }
761 }
762
763out:
764 ubifs_release_lprops(c);
765 return err;
766}
767
768/**
769 * ubifs_fixup_free_space - find & fix all LEBs with free space.
770 * @c: UBIFS file-system description object
771 *
772 * This function fixes up LEBs containing free space on first mount, if the
773 * appropriate flag was set when the FS was created. Each LEB with one or more
774 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
775 * the free space is actually erased. E.g., this is necessary for some NAND
776 * chips, since the free space may have been programmed like real "0xff" data
777 * (generating a non-0xff ECC), causing future writes to the not-really-erased
778 * NAND pages to behave badly. After the space is fixed up, the superblock flag
779 * is cleared, so that this is skipped for all future mounts.
780 */
781int ubifs_fixup_free_space(struct ubifs_info *c)
782{
783 int err;
784 struct ubifs_sb_node *sup;
785
786 ubifs_assert(c->space_fixup);
787 ubifs_assert(!c->ro_mount);
788
789 ubifs_msg("start fixing up free space");
790
791 err = fixup_free_space(c);
792 if (err)
793 return err;
794
795 sup = ubifs_read_sb_node(c);
796 if (IS_ERR(sup))
797 return PTR_ERR(sup);
798
799 /* Free-space fixup is no longer required */
800 c->space_fixup = 0;
801 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
802
803 err = ubifs_write_sb_node(c, sup);
804 kfree(sup);
805 if (err)
806 return err;
807
808 ubifs_msg("free space fixup complete");
809 return err;
810}