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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 struct timespec64 ts;
88 u8 hash[UBIFS_HASH_ARR_SZ];
89 u8 hash_lpt[UBIFS_HASH_ARR_SZ];
90
91 /* Some functions called from here depend on the @c->key_len filed */
92 c->key_len = UBIFS_SK_LEN;
93
94 /*
95 * First of all, we have to calculate default file-system geometry -
96 * log size, journal size, etc.
97 */
98 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
99 /* We can first multiply then divide and have no overflow */
100 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
101 else
102 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
103
104 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
105 jnl_lebs = UBIFS_MIN_JNL_LEBS;
106 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
107 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
108
109 /*
110 * The log should be large enough to fit reference nodes for all bud
111 * LEBs. Because buds do not have to start from the beginning of LEBs
112 * (half of the LEB may contain committed data), the log should
113 * generally be larger, make it twice as large.
114 */
115 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
116 log_lebs = tmp / c->leb_size;
117 /* Plus one LEB reserved for commit */
118 log_lebs += 1;
119 if (c->leb_cnt - min_leb_cnt > 8) {
120 /* And some extra space to allow writes while committing */
121 log_lebs += 1;
122 min_leb_cnt += 1;
123 }
124
125 max_buds = jnl_lebs - log_lebs;
126 if (max_buds < UBIFS_MIN_BUD_LEBS)
127 max_buds = UBIFS_MIN_BUD_LEBS;
128
129 /*
130 * Orphan nodes are stored in a separate area. One node can store a lot
131 * of orphan inode numbers, but when new orphan comes we just add a new
132 * orphan node. At some point the nodes are consolidated into one
133 * orphan node.
134 */
135 orph_lebs = UBIFS_MIN_ORPH_LEBS;
136 if (c->leb_cnt - min_leb_cnt > 1)
137 /*
138 * For debugging purposes it is better to have at least 2
139 * orphan LEBs, because the orphan subsystem would need to do
140 * consolidations and would be stressed more.
141 */
142 orph_lebs += 1;
143
144 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
145 main_lebs -= orph_lebs;
146
147 lpt_first = UBIFS_LOG_LNUM + log_lebs;
148 c->lsave_cnt = DEFAULT_LSAVE_CNT;
149 c->max_leb_cnt = c->leb_cnt;
150 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
151 &big_lpt, hash_lpt);
152 if (err)
153 return err;
154
155 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
156 lpt_first + lpt_lebs - 1);
157
158 main_first = c->leb_cnt - main_lebs;
159
160 sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL);
161 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
162 idx_node_size = ubifs_idx_node_sz(c, 1);
163 idx = kzalloc(ALIGN(idx_node_size, c->min_io_size), GFP_KERNEL);
164 ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL);
165 cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL);
166
167 if (!sup || !mst || !idx || !ino || !cs) {
168 err = -ENOMEM;
169 goto out;
170 }
171
172 /* Create default superblock */
173
174 tmp64 = (long long)max_buds * c->leb_size;
175 if (big_lpt)
176 sup_flags |= UBIFS_FLG_BIGLPT;
177 if (ubifs_default_version > 4)
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 = cpu_to_le16(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_default_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_coarse_real_ts64(&ts);
295 tmp_le64 = cpu_to_le64(ts.tv_sec);
296 ino->atime_sec = tmp_le64;
297 ino->ctime_sec = tmp_le64;
298 ino->mtime_sec = tmp_le64;
299 ino->atime_nsec = 0;
300 ino->ctime_nsec = 0;
301 ino->mtime_nsec = 0;
302 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
303 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
304
305 /* Set compression enabled by default */
306 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
307
308 dbg_gen("root inode created at LEB %d:0",
309 main_first + DEFAULT_DATA_LEB);
310
311 /*
312 * The first node in the log has to be the commit start node. This is
313 * always the case during normal file-system operation. Write a fake
314 * commit start node to the log.
315 */
316
317 cs->ch.node_type = UBIFS_CS_NODE;
318
319 err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0,
320 offsetof(struct ubifs_sb_node, hmac));
321 if (err)
322 goto out;
323
324 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
325 main_first + DEFAULT_DATA_LEB, 0);
326 if (err)
327 goto out;
328
329 ubifs_node_calc_hash(c, ino, hash);
330 ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br));
331
332 err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0);
333 if (err)
334 goto out;
335
336 ubifs_node_calc_hash(c, idx, hash);
337 ubifs_copy_hash(c, hash, mst->hash_root_idx);
338
339 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
340 offsetof(struct ubifs_mst_node, hmac));
341 if (err)
342 goto out;
343
344 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
345 0, offsetof(struct ubifs_mst_node, hmac));
346 if (err)
347 goto out;
348
349 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
350 if (err)
351 goto out;
352
353 ubifs_msg(c, "default file-system created");
354
355 err = 0;
356out:
357 kfree(sup);
358 kfree(mst);
359 kfree(idx);
360 kfree(ino);
361 kfree(cs);
362
363 return err;
364}
365
366/**
367 * validate_sb - validate superblock node.
368 * @c: UBIFS file-system description object
369 * @sup: superblock node
370 *
371 * This function validates superblock node @sup. Since most of data was read
372 * from the superblock and stored in @c, the function validates fields in @c
373 * instead. Returns zero in case of success and %-EINVAL in case of validation
374 * failure.
375 */
376static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
377{
378 long long max_bytes;
379 int err = 1, min_leb_cnt;
380
381 if (!c->key_hash) {
382 err = 2;
383 goto failed;
384 }
385
386 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
387 err = 3;
388 goto failed;
389 }
390
391 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
392 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real",
393 le32_to_cpu(sup->min_io_size), c->min_io_size);
394 goto failed;
395 }
396
397 if (le32_to_cpu(sup->leb_size) != c->leb_size) {
398 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real",
399 le32_to_cpu(sup->leb_size), c->leb_size);
400 goto failed;
401 }
402
403 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
404 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
405 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
406 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
407 err = 4;
408 goto failed;
409 }
410
411 /*
412 * Calculate minimum allowed amount of main area LEBs. This is very
413 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
414 * have just read from the superblock.
415 */
416 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
417 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
418
419 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
420 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
421 c->leb_cnt, c->vi.size, min_leb_cnt);
422 goto failed;
423 }
424
425 if (c->max_leb_cnt < c->leb_cnt) {
426 ubifs_err(c, "max. LEB count %d less than LEB count %d",
427 c->max_leb_cnt, c->leb_cnt);
428 goto failed;
429 }
430
431 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
432 ubifs_err(c, "too few main LEBs count %d, must be at least %d",
433 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
434 goto failed;
435 }
436
437 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
438 if (c->max_bud_bytes < max_bytes) {
439 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes",
440 c->max_bud_bytes, max_bytes);
441 goto failed;
442 }
443
444 max_bytes = (long long)c->leb_size * c->main_lebs;
445 if (c->max_bud_bytes > max_bytes) {
446 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area",
447 c->max_bud_bytes, max_bytes);
448 goto failed;
449 }
450
451 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
452 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
453 err = 9;
454 goto failed;
455 }
456
457 if (c->fanout < UBIFS_MIN_FANOUT ||
458 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
459 err = 10;
460 goto failed;
461 }
462
463 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
464 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
465 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
466 err = 11;
467 goto failed;
468 }
469
470 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
471 c->orph_lebs + c->main_lebs != c->leb_cnt) {
472 err = 12;
473 goto failed;
474 }
475
476 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
477 err = 13;
478 goto failed;
479 }
480
481 if (c->rp_size < 0 || max_bytes < c->rp_size) {
482 err = 14;
483 goto failed;
484 }
485
486 if (le32_to_cpu(sup->time_gran) > 1000000000 ||
487 le32_to_cpu(sup->time_gran) < 1) {
488 err = 15;
489 goto failed;
490 }
491
492 if (!c->double_hash && c->fmt_version >= 5) {
493 err = 16;
494 goto failed;
495 }
496
497 if (c->encrypted && c->fmt_version < 5) {
498 err = 17;
499 goto failed;
500 }
501
502 return 0;
503
504failed:
505 ubifs_err(c, "bad superblock, error %d", err);
506 ubifs_dump_node(c, sup);
507 return -EINVAL;
508}
509
510/**
511 * ubifs_read_sb_node - read superblock node.
512 * @c: UBIFS file-system description object
513 *
514 * This function returns a pointer to the superblock node or a negative error
515 * code. Note, the user of this function is responsible of kfree()'ing the
516 * returned superblock buffer.
517 */
518static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
519{
520 struct ubifs_sb_node *sup;
521 int err;
522
523 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
524 if (!sup)
525 return ERR_PTR(-ENOMEM);
526
527 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
528 UBIFS_SB_LNUM, 0);
529 if (err) {
530 kfree(sup);
531 return ERR_PTR(err);
532 }
533
534 return sup;
535}
536
537static int authenticate_sb_node(struct ubifs_info *c,
538 const struct ubifs_sb_node *sup)
539{
540 unsigned int sup_flags = le32_to_cpu(sup->flags);
541 u8 hmac_wkm[UBIFS_HMAC_ARR_SZ];
542 int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION);
543 int hash_algo;
544 int err;
545
546 if (c->authenticated && !authenticated) {
547 ubifs_err(c, "authenticated FS forced, but found FS without authentication");
548 return -EINVAL;
549 }
550
551 if (!c->authenticated && authenticated) {
552 ubifs_err(c, "authenticated FS found, but no key given");
553 return -EINVAL;
554 }
555
556 ubifs_msg(c, "Mounting in %sauthenticated mode",
557 c->authenticated ? "" : "un");
558
559 if (!c->authenticated)
560 return 0;
561
562 if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION))
563 return -EOPNOTSUPP;
564
565 hash_algo = le16_to_cpu(sup->hash_algo);
566 if (hash_algo >= HASH_ALGO__LAST) {
567 ubifs_err(c, "superblock uses unknown hash algo %d",
568 hash_algo);
569 return -EINVAL;
570 }
571
572 if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) {
573 ubifs_err(c, "This filesystem uses %s for hashing,"
574 " but %s is specified", hash_algo_name[hash_algo],
575 c->auth_hash_name);
576 return -EINVAL;
577 }
578
579 /*
580 * The super block node can either be authenticated by a HMAC or
581 * by a signature in a ubifs_sig_node directly following the
582 * super block node to support offline image creation.
583 */
584 if (ubifs_hmac_zero(c, sup->hmac)) {
585 err = ubifs_sb_verify_signature(c, sup);
586 } else {
587 err = ubifs_hmac_wkm(c, hmac_wkm);
588 if (err)
589 return err;
590 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) {
591 ubifs_err(c, "provided key does not fit");
592 return -ENOKEY;
593 }
594 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup),
595 offsetof(struct ubifs_sb_node,
596 hmac));
597 }
598
599 if (err)
600 ubifs_err(c, "Failed to authenticate superblock: %d", err);
601
602 return err;
603}
604
605/**
606 * ubifs_write_sb_node - write superblock node.
607 * @c: UBIFS file-system description object
608 * @sup: superblock node read with 'ubifs_read_sb_node()'
609 *
610 * This function returns %0 on success and a negative error code on failure.
611 */
612int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
613{
614 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
615 int err;
616
617 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ,
618 offsetof(struct ubifs_sb_node, hmac), 1);
619 if (err)
620 return err;
621
622 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);
623}
624
625/**
626 * ubifs_read_superblock - read superblock.
627 * @c: UBIFS file-system description object
628 *
629 * This function finds, reads and checks the superblock. If an empty UBI volume
630 * is being mounted, this function creates default superblock. Returns zero in
631 * case of success, and a negative error code in case of failure.
632 */
633int ubifs_read_superblock(struct ubifs_info *c)
634{
635 int err, sup_flags;
636 struct ubifs_sb_node *sup;
637
638 if (c->empty) {
639 err = create_default_filesystem(c);
640 if (err)
641 return err;
642 }
643
644 sup = ubifs_read_sb_node(c);
645 if (IS_ERR(sup))
646 return PTR_ERR(sup);
647
648 c->sup_node = sup;
649
650 c->fmt_version = le32_to_cpu(sup->fmt_version);
651 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
652
653 /*
654 * The software supports all previous versions but not future versions,
655 * due to the unavailability of time-travelling equipment.
656 */
657 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
658 ubifs_assert(c, !c->ro_media || c->ro_mount);
659 if (!c->ro_mount ||
660 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
661 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
662 c->fmt_version, c->ro_compat_version,
663 UBIFS_FORMAT_VERSION,
664 UBIFS_RO_COMPAT_VERSION);
665 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
666 ubifs_msg(c, "only R/O mounting is possible");
667 err = -EROFS;
668 } else
669 err = -EINVAL;
670 goto out;
671 }
672
673 /*
674 * The FS is mounted R/O, and the media format is
675 * R/O-compatible with the UBIFS implementation, so we can
676 * mount.
677 */
678 c->rw_incompat = 1;
679 }
680
681 if (c->fmt_version < 3) {
682 ubifs_err(c, "on-flash format version %d is not supported",
683 c->fmt_version);
684 err = -EINVAL;
685 goto out;
686 }
687
688 switch (sup->key_hash) {
689 case UBIFS_KEY_HASH_R5:
690 c->key_hash = key_r5_hash;
691 c->key_hash_type = UBIFS_KEY_HASH_R5;
692 break;
693
694 case UBIFS_KEY_HASH_TEST:
695 c->key_hash = key_test_hash;
696 c->key_hash_type = UBIFS_KEY_HASH_TEST;
697 break;
698 }
699
700 c->key_fmt = sup->key_fmt;
701
702 switch (c->key_fmt) {
703 case UBIFS_SIMPLE_KEY_FMT:
704 c->key_len = UBIFS_SK_LEN;
705 break;
706 default:
707 ubifs_err(c, "unsupported key format");
708 err = -EINVAL;
709 goto out;
710 }
711
712 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
713 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
714 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
715 c->log_lebs = le32_to_cpu(sup->log_lebs);
716 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
717 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
718 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
719 c->fanout = le32_to_cpu(sup->fanout);
720 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
721 c->rp_size = le64_to_cpu(sup->rp_size);
722 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
723 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
724 sup_flags = le32_to_cpu(sup->flags);
725 if (!c->mount_opts.override_compr)
726 c->default_compr = le16_to_cpu(sup->default_compr);
727
728 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
729 memcpy(&c->uuid, &sup->uuid, 16);
730 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
731 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
732 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH);
733 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION);
734
735 err = authenticate_sb_node(c, sup);
736 if (err)
737 goto out;
738
739 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) {
740 ubifs_err(c, "Unknown feature flags found: %#x",
741 sup_flags & ~UBIFS_FLG_MASK);
742 err = -EINVAL;
743 goto out;
744 }
745
746 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) {
747 ubifs_err(c, "file system contains encrypted files but UBIFS"
748 " was built without crypto support.");
749 err = -EINVAL;
750 goto out;
751 }
752
753 /* Automatically increase file system size to the maximum size */
754 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
755 int old_leb_cnt = c->leb_cnt;
756
757 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
758 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
759
760 c->superblock_need_write = 1;
761
762 dbg_mnt("Auto resizing from %d LEBs to %d LEBs",
763 old_leb_cnt, c->leb_cnt);
764 }
765
766 c->log_bytes = (long long)c->log_lebs * c->leb_size;
767 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
768 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
769 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
770 c->orph_first = c->lpt_last + 1;
771 c->orph_last = c->orph_first + c->orph_lebs - 1;
772 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
773 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
774 c->main_first = c->leb_cnt - c->main_lebs;
775
776 err = validate_sb(c, sup);
777out:
778 return err;
779}
780
781/**
782 * fixup_leb - fixup/unmap an LEB containing free space.
783 * @c: UBIFS file-system description object
784 * @lnum: the LEB number to fix up
785 * @len: number of used bytes in LEB (starting at offset 0)
786 *
787 * This function reads the contents of the given LEB number @lnum, then fixes
788 * it up, so that empty min. I/O units in the end of LEB are actually erased on
789 * flash (rather than being just all-0xff real data). If the LEB is completely
790 * empty, it is simply unmapped.
791 */
792static int fixup_leb(struct ubifs_info *c, int lnum, int len)
793{
794 int err;
795
796 ubifs_assert(c, len >= 0);
797 ubifs_assert(c, len % c->min_io_size == 0);
798 ubifs_assert(c, len < c->leb_size);
799
800 if (len == 0) {
801 dbg_mnt("unmap empty LEB %d", lnum);
802 return ubifs_leb_unmap(c, lnum);
803 }
804
805 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
806 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
807 if (err)
808 return err;
809
810 return ubifs_leb_change(c, lnum, c->sbuf, len);
811}
812
813/**
814 * fixup_free_space - find & remap all LEBs containing free space.
815 * @c: UBIFS file-system description object
816 *
817 * This function walks through all LEBs in the filesystem and fiexes up those
818 * containing free/empty space.
819 */
820static int fixup_free_space(struct ubifs_info *c)
821{
822 int lnum, err = 0;
823 struct ubifs_lprops *lprops;
824
825 ubifs_get_lprops(c);
826
827 /* Fixup LEBs in the master area */
828 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
829 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
830 if (err)
831 goto out;
832 }
833
834 /* Unmap unused log LEBs */
835 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
836 while (lnum != c->ltail_lnum) {
837 err = fixup_leb(c, lnum, 0);
838 if (err)
839 goto out;
840 lnum = ubifs_next_log_lnum(c, lnum);
841 }
842
843 /*
844 * Fixup the log head which contains the only a CS node at the
845 * beginning.
846 */
847 err = fixup_leb(c, c->lhead_lnum,
848 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
849 if (err)
850 goto out;
851
852 /* Fixup LEBs in the LPT area */
853 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
854 int free = c->ltab[lnum - c->lpt_first].free;
855
856 if (free > 0) {
857 err = fixup_leb(c, lnum, c->leb_size - free);
858 if (err)
859 goto out;
860 }
861 }
862
863 /* Unmap LEBs in the orphans area */
864 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
865 err = fixup_leb(c, lnum, 0);
866 if (err)
867 goto out;
868 }
869
870 /* Fixup LEBs in the main area */
871 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
872 lprops = ubifs_lpt_lookup(c, lnum);
873 if (IS_ERR(lprops)) {
874 err = PTR_ERR(lprops);
875 goto out;
876 }
877
878 if (lprops->free > 0) {
879 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
880 if (err)
881 goto out;
882 }
883 }
884
885out:
886 ubifs_release_lprops(c);
887 return err;
888}
889
890/**
891 * ubifs_fixup_free_space - find & fix all LEBs with free space.
892 * @c: UBIFS file-system description object
893 *
894 * This function fixes up LEBs containing free space on first mount, if the
895 * appropriate flag was set when the FS was created. Each LEB with one or more
896 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
897 * the free space is actually erased. E.g., this is necessary for some NAND
898 * chips, since the free space may have been programmed like real "0xff" data
899 * (generating a non-0xff ECC), causing future writes to the not-really-erased
900 * NAND pages to behave badly. After the space is fixed up, the superblock flag
901 * is cleared, so that this is skipped for all future mounts.
902 */
903int ubifs_fixup_free_space(struct ubifs_info *c)
904{
905 int err;
906 struct ubifs_sb_node *sup = c->sup_node;
907
908 ubifs_assert(c, c->space_fixup);
909 ubifs_assert(c, !c->ro_mount);
910
911 ubifs_msg(c, "start fixing up free space");
912
913 err = fixup_free_space(c);
914 if (err)
915 return err;
916
917 /* Free-space fixup is no longer required */
918 c->space_fixup = 0;
919 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
920
921 c->superblock_need_write = 1;
922
923 ubifs_msg(c, "free space fixup complete");
924 return err;
925}
926
927int ubifs_enable_encryption(struct ubifs_info *c)
928{
929 int err;
930 struct ubifs_sb_node *sup = c->sup_node;
931
932 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION))
933 return -EOPNOTSUPP;
934
935 if (c->encrypted)
936 return 0;
937
938 if (c->ro_mount || c->ro_media)
939 return -EROFS;
940
941 if (c->fmt_version < 5) {
942 ubifs_err(c, "on-flash format version 5 is needed for encryption");
943 return -EINVAL;
944 }
945
946 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION);
947
948 err = ubifs_write_sb_node(c, sup);
949 if (!err)
950 c->encrypted = 1;
951
952 return err;
953}
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 if (err)
336 return err;
337
338 ubifs_msg(c, "default file-system created");
339 return 0;
340}
341
342/**
343 * validate_sb - validate superblock node.
344 * @c: UBIFS file-system description object
345 * @sup: superblock node
346 *
347 * This function validates superblock node @sup. Since most of data was read
348 * from the superblock and stored in @c, the function validates fields in @c
349 * instead. Returns zero in case of success and %-EINVAL in case of validation
350 * failure.
351 */
352static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
353{
354 long long max_bytes;
355 int err = 1, min_leb_cnt;
356
357 if (!c->key_hash) {
358 err = 2;
359 goto failed;
360 }
361
362 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
363 err = 3;
364 goto failed;
365 }
366
367 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
368 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real",
369 le32_to_cpu(sup->min_io_size), c->min_io_size);
370 goto failed;
371 }
372
373 if (le32_to_cpu(sup->leb_size) != c->leb_size) {
374 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real",
375 le32_to_cpu(sup->leb_size), c->leb_size);
376 goto failed;
377 }
378
379 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
380 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
381 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
382 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
383 err = 4;
384 goto failed;
385 }
386
387 /*
388 * Calculate minimum allowed amount of main area LEBs. This is very
389 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
390 * have just read from the superblock.
391 */
392 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
393 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
394
395 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
396 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
397 c->leb_cnt, c->vi.size, min_leb_cnt);
398 goto failed;
399 }
400
401 if (c->max_leb_cnt < c->leb_cnt) {
402 ubifs_err(c, "max. LEB count %d less than LEB count %d",
403 c->max_leb_cnt, c->leb_cnt);
404 goto failed;
405 }
406
407 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
408 ubifs_err(c, "too few main LEBs count %d, must be at least %d",
409 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
410 goto failed;
411 }
412
413 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
414 if (c->max_bud_bytes < max_bytes) {
415 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes",
416 c->max_bud_bytes, max_bytes);
417 goto failed;
418 }
419
420 max_bytes = (long long)c->leb_size * c->main_lebs;
421 if (c->max_bud_bytes > max_bytes) {
422 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes 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 >= 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(c, "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(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
553 c->fmt_version, c->ro_compat_version,
554 UBIFS_FORMAT_VERSION,
555 UBIFS_RO_COMPAT_VERSION);
556 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
557 ubifs_msg(c, "only R/O mounting is possible");
558 err = -EROFS;
559 } else
560 err = -EINVAL;
561 goto out;
562 }
563
564 /*
565 * The FS is mounted R/O, and the media format is
566 * R/O-compatible with the UBIFS implementation, so we can
567 * mount.
568 */
569 c->rw_incompat = 1;
570 }
571
572 if (c->fmt_version < 3) {
573 ubifs_err(c, "on-flash format version %d is not supported",
574 c->fmt_version);
575 err = -EINVAL;
576 goto out;
577 }
578
579 switch (sup->key_hash) {
580 case UBIFS_KEY_HASH_R5:
581 c->key_hash = key_r5_hash;
582 c->key_hash_type = UBIFS_KEY_HASH_R5;
583 break;
584
585 case UBIFS_KEY_HASH_TEST:
586 c->key_hash = key_test_hash;
587 c->key_hash_type = UBIFS_KEY_HASH_TEST;
588 break;
589 };
590
591 c->key_fmt = sup->key_fmt;
592
593 switch (c->key_fmt) {
594 case UBIFS_SIMPLE_KEY_FMT:
595 c->key_len = UBIFS_SK_LEN;
596 break;
597 default:
598 ubifs_err(c, "unsupported key format");
599 err = -EINVAL;
600 goto out;
601 }
602
603 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
604 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
605 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
606 c->log_lebs = le32_to_cpu(sup->log_lebs);
607 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
608 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
609 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
610 c->fanout = le32_to_cpu(sup->fanout);
611 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
612 c->rp_size = le64_to_cpu(sup->rp_size);
613 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
614 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
615 sup_flags = le32_to_cpu(sup->flags);
616 if (!c->mount_opts.override_compr)
617 c->default_compr = le16_to_cpu(sup->default_compr);
618
619 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
620 memcpy(&c->uuid, &sup->uuid, 16);
621 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
622 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
623
624 /* Automatically increase file system size to the maximum size */
625 c->old_leb_cnt = c->leb_cnt;
626 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
627 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
628 if (c->ro_mount)
629 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
630 c->old_leb_cnt, c->leb_cnt);
631 else {
632 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
633 c->old_leb_cnt, c->leb_cnt);
634 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
635 err = ubifs_write_sb_node(c, sup);
636 if (err)
637 goto out;
638 c->old_leb_cnt = c->leb_cnt;
639 }
640 }
641
642 c->log_bytes = (long long)c->log_lebs * c->leb_size;
643 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
644 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
645 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
646 c->orph_first = c->lpt_last + 1;
647 c->orph_last = c->orph_first + c->orph_lebs - 1;
648 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
649 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
650 c->main_first = c->leb_cnt - c->main_lebs;
651
652 err = validate_sb(c, sup);
653out:
654 kfree(sup);
655 return err;
656}
657
658/**
659 * fixup_leb - fixup/unmap an LEB containing free space.
660 * @c: UBIFS file-system description object
661 * @lnum: the LEB number to fix up
662 * @len: number of used bytes in LEB (starting at offset 0)
663 *
664 * This function reads the contents of the given LEB number @lnum, then fixes
665 * it up, so that empty min. I/O units in the end of LEB are actually erased on
666 * flash (rather than being just all-0xff real data). If the LEB is completely
667 * empty, it is simply unmapped.
668 */
669static int fixup_leb(struct ubifs_info *c, int lnum, int len)
670{
671 int err;
672
673 ubifs_assert(len >= 0);
674 ubifs_assert(len % c->min_io_size == 0);
675 ubifs_assert(len < c->leb_size);
676
677 if (len == 0) {
678 dbg_mnt("unmap empty LEB %d", lnum);
679 return ubifs_leb_unmap(c, lnum);
680 }
681
682 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
683 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
684 if (err)
685 return err;
686
687 return ubifs_leb_change(c, lnum, c->sbuf, len);
688}
689
690/**
691 * fixup_free_space - find & remap all LEBs containing free space.
692 * @c: UBIFS file-system description object
693 *
694 * This function walks through all LEBs in the filesystem and fiexes up those
695 * containing free/empty space.
696 */
697static int fixup_free_space(struct ubifs_info *c)
698{
699 int lnum, err = 0;
700 struct ubifs_lprops *lprops;
701
702 ubifs_get_lprops(c);
703
704 /* Fixup LEBs in the master area */
705 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
706 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
707 if (err)
708 goto out;
709 }
710
711 /* Unmap unused log LEBs */
712 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
713 while (lnum != c->ltail_lnum) {
714 err = fixup_leb(c, lnum, 0);
715 if (err)
716 goto out;
717 lnum = ubifs_next_log_lnum(c, lnum);
718 }
719
720 /*
721 * Fixup the log head which contains the only a CS node at the
722 * beginning.
723 */
724 err = fixup_leb(c, c->lhead_lnum,
725 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
726 if (err)
727 goto out;
728
729 /* Fixup LEBs in the LPT area */
730 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
731 int free = c->ltab[lnum - c->lpt_first].free;
732
733 if (free > 0) {
734 err = fixup_leb(c, lnum, c->leb_size - free);
735 if (err)
736 goto out;
737 }
738 }
739
740 /* Unmap LEBs in the orphans area */
741 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
742 err = fixup_leb(c, lnum, 0);
743 if (err)
744 goto out;
745 }
746
747 /* Fixup LEBs in the main area */
748 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
749 lprops = ubifs_lpt_lookup(c, lnum);
750 if (IS_ERR(lprops)) {
751 err = PTR_ERR(lprops);
752 goto out;
753 }
754
755 if (lprops->free > 0) {
756 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
757 if (err)
758 goto out;
759 }
760 }
761
762out:
763 ubifs_release_lprops(c);
764 return err;
765}
766
767/**
768 * ubifs_fixup_free_space - find & fix all LEBs with free space.
769 * @c: UBIFS file-system description object
770 *
771 * This function fixes up LEBs containing free space on first mount, if the
772 * appropriate flag was set when the FS was created. Each LEB with one or more
773 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
774 * the free space is actually erased. E.g., this is necessary for some NAND
775 * chips, since the free space may have been programmed like real "0xff" data
776 * (generating a non-0xff ECC), causing future writes to the not-really-erased
777 * NAND pages to behave badly. After the space is fixed up, the superblock flag
778 * is cleared, so that this is skipped for all future mounts.
779 */
780int ubifs_fixup_free_space(struct ubifs_info *c)
781{
782 int err;
783 struct ubifs_sb_node *sup;
784
785 ubifs_assert(c->space_fixup);
786 ubifs_assert(!c->ro_mount);
787
788 ubifs_msg(c, "start fixing up free space");
789
790 err = fixup_free_space(c);
791 if (err)
792 return err;
793
794 sup = ubifs_read_sb_node(c);
795 if (IS_ERR(sup))
796 return PTR_ERR(sup);
797
798 /* Free-space fixup is no longer required */
799 c->space_fixup = 0;
800 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
801
802 err = ubifs_write_sb_node(c, sup);
803 kfree(sup);
804 if (err)
805 return err;
806
807 ubifs_msg(c, "free space fixup complete");
808 return err;
809}