1 // SPDX-License-Identifier: GPL-2.0+
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 #ifndef __UBOOT__
19 #include <log.h>
20 #include <dm/devres.h>
21 #include <linux/slab.h>
22 #include <linux/random.h>
23 #include <linux/math64.h>
24 #else
25
26 #include <linux/compat.h>
27 #include <linux/err.h>
28 #include <ubi_uboot.h>
29 #include <linux/stat.h>
30 #endif
31
32 /*
33 * Default journal size in logical eraseblocks as a percent of total
34 * flash size.
35 */
36 #define DEFAULT_JNL_PERCENT 5
37
38 /* Default maximum journal size in bytes */
39 #define DEFAULT_MAX_JNL (32*1024*1024)
40
41 /* Default indexing tree fanout */
42 #define DEFAULT_FANOUT 8
43
44 /* Default number of data journal heads */
45 #define DEFAULT_JHEADS_CNT 1
46
47 /* Default positions of different LEBs in the main area */
48 #define DEFAULT_IDX_LEB 0
49 #define DEFAULT_DATA_LEB 1
50 #define DEFAULT_GC_LEB 2
51
52 /* Default number of LEB numbers in LPT's save table */
53 #define DEFAULT_LSAVE_CNT 256
54
55 /* Default reserved pool size as a percent of maximum free space */
56 #define DEFAULT_RP_PERCENT 5
57
58 /* The default maximum size of reserved pool in bytes */
59 #define DEFAULT_MAX_RP_SIZE (5*1024*1024)
60
61 /* Default time granularity in nanoseconds */
62 #define DEFAULT_TIME_GRAN 1000000000
63
64 #ifndef __UBOOT__
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 */
create_default_filesystem(struct ubifs_info * c)72 static 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 long long tmp64, main_bytes;
85 __le64 tmp_le64;
86
87 /* Some functions called from here depend on the @c->key_len filed */
88 c->key_len = UBIFS_SK_LEN;
89
90 /*
91 * First of all, we have to calculate default file-system geometry -
92 * log size, journal size, etc.
93 */
94 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
95 /* We can first multiply then divide and have no overflow */
96 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
97 else
98 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
99
100 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
101 jnl_lebs = UBIFS_MIN_JNL_LEBS;
102 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
103 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
104
105 /*
106 * The log should be large enough to fit reference nodes for all bud
107 * LEBs. Because buds do not have to start from the beginning of LEBs
108 * (half of the LEB may contain committed data), the log should
109 * generally be larger, make it twice as large.
110 */
111 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
112 log_lebs = tmp / c->leb_size;
113 /* Plus one LEB reserved for commit */
114 log_lebs += 1;
115 if (c->leb_cnt - min_leb_cnt > 8) {
116 /* And some extra space to allow writes while committing */
117 log_lebs += 1;
118 min_leb_cnt += 1;
119 }
120
121 max_buds = jnl_lebs - log_lebs;
122 if (max_buds < UBIFS_MIN_BUD_LEBS)
123 max_buds = UBIFS_MIN_BUD_LEBS;
124
125 /*
126 * Orphan nodes are stored in a separate area. One node can store a lot
127 * of orphan inode numbers, but when new orphan comes we just add a new
128 * orphan node. At some point the nodes are consolidated into one
129 * orphan node.
130 */
131 orph_lebs = UBIFS_MIN_ORPH_LEBS;
132 if (c->leb_cnt - min_leb_cnt > 1)
133 /*
134 * For debugging purposes it is better to have at least 2
135 * orphan LEBs, because the orphan subsystem would need to do
136 * consolidations and would be stressed more.
137 */
138 orph_lebs += 1;
139
140 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
141 main_lebs -= orph_lebs;
142
143 lpt_first = UBIFS_LOG_LNUM + log_lebs;
144 c->lsave_cnt = DEFAULT_LSAVE_CNT;
145 c->max_leb_cnt = c->leb_cnt;
146 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
147 &big_lpt);
148 if (err)
149 return err;
150
151 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
152 lpt_first + lpt_lebs - 1);
153
154 main_first = c->leb_cnt - main_lebs;
155
156 /* Create default superblock */
157 tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
158 sup = kzalloc(tmp, GFP_KERNEL);
159 if (!sup)
160 return -ENOMEM;
161
162 tmp64 = (long long)max_buds * c->leb_size;
163 if (big_lpt)
164 sup_flags |= UBIFS_FLG_BIGLPT;
165
166 sup->ch.node_type = UBIFS_SB_NODE;
167 sup->key_hash = UBIFS_KEY_HASH_R5;
168 sup->flags = cpu_to_le32(sup_flags);
169 sup->min_io_size = cpu_to_le32(c->min_io_size);
170 sup->leb_size = cpu_to_le32(c->leb_size);
171 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
172 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
173 sup->max_bud_bytes = cpu_to_le64(tmp64);
174 sup->log_lebs = cpu_to_le32(log_lebs);
175 sup->lpt_lebs = cpu_to_le32(lpt_lebs);
176 sup->orph_lebs = cpu_to_le32(orph_lebs);
177 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
178 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
179 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
180 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
181 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
182 if (c->mount_opts.override_compr)
183 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
184 else
185 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
186
187 generate_random_uuid(sup->uuid);
188
189 main_bytes = (long long)main_lebs * c->leb_size;
190 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
191 if (tmp64 > DEFAULT_MAX_RP_SIZE)
192 tmp64 = DEFAULT_MAX_RP_SIZE;
193 sup->rp_size = cpu_to_le64(tmp64);
194 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
195
196 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0);
197 kfree(sup);
198 if (err)
199 return err;
200
201 dbg_gen("default superblock created at LEB 0:0");
202
203 /* Create default master node */
204 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
205 if (!mst)
206 return -ENOMEM;
207
208 mst->ch.node_type = UBIFS_MST_NODE;
209 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
210 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
211 mst->cmt_no = 0;
212 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
213 mst->root_offs = 0;
214 tmp = ubifs_idx_node_sz(c, 1);
215 mst->root_len = cpu_to_le32(tmp);
216 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
217 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
218 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
219 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
220 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
221 mst->lpt_offs = cpu_to_le32(c->lpt_offs);
222 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
223 mst->nhead_offs = cpu_to_le32(c->nhead_offs);
224 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
225 mst->ltab_offs = cpu_to_le32(c->ltab_offs);
226 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
227 mst->lsave_offs = cpu_to_le32(c->lsave_offs);
228 mst->lscan_lnum = cpu_to_le32(main_first);
229 mst->empty_lebs = cpu_to_le32(main_lebs - 2);
230 mst->idx_lebs = cpu_to_le32(1);
231 mst->leb_cnt = cpu_to_le32(c->leb_cnt);
232
233 /* Calculate lprops statistics */
234 tmp64 = main_bytes;
235 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
236 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
237 mst->total_free = cpu_to_le64(tmp64);
238
239 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
240 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
241 UBIFS_INO_NODE_SZ;
242 tmp64 += ino_waste;
243 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
244 mst->total_dirty = cpu_to_le64(tmp64);
245
246 /* The indexing LEB does not contribute to dark space */
247 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
248 mst->total_dark = cpu_to_le64(tmp64);
249
250 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
251
252 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0);
253 if (err) {
254 kfree(mst);
255 return err;
256 }
257 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
258 0);
259 kfree(mst);
260 if (err)
261 return err;
262
263 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
264
265 /* Create the root indexing node */
266 tmp = ubifs_idx_node_sz(c, 1);
267 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
268 if (!idx)
269 return -ENOMEM;
270
271 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
272 c->key_hash = key_r5_hash;
273
274 idx->ch.node_type = UBIFS_IDX_NODE;
275 idx->child_cnt = cpu_to_le16(1);
276 ino_key_init(c, &key, UBIFS_ROOT_INO);
277 br = ubifs_idx_branch(c, idx, 0);
278 key_write_idx(c, &key, &br->key);
279 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
280 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
281 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0);
282 kfree(idx);
283 if (err)
284 return err;
285
286 dbg_gen("default root indexing node created LEB %d:0",
287 main_first + DEFAULT_IDX_LEB);
288
289 /* Create default root inode */
290 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
291 ino = kzalloc(tmp, GFP_KERNEL);
292 if (!ino)
293 return -ENOMEM;
294
295 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
296 ino->ch.node_type = UBIFS_INO_NODE;
297 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
298 ino->nlink = cpu_to_le32(2);
299 tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
300 ino->atime_sec = tmp_le64;
301 ino->ctime_sec = tmp_le64;
302 ino->mtime_sec = tmp_le64;
303 ino->atime_nsec = 0;
304 ino->ctime_nsec = 0;
305 ino->mtime_nsec = 0;
306 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
307 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
308
309 /* Set compression enabled by default */
310 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
311
312 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
313 main_first + DEFAULT_DATA_LEB, 0);
314 kfree(ino);
315 if (err)
316 return err;
317
318 dbg_gen("root inode created at LEB %d:0",
319 main_first + DEFAULT_DATA_LEB);
320
321 /*
322 * The first node in the log has to be the commit start node. This is
323 * always the case during normal file-system operation. Write a fake
324 * commit start node to the log.
325 */
326 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
327 cs = kzalloc(tmp, GFP_KERNEL);
328 if (!cs)
329 return -ENOMEM;
330
331 cs->ch.node_type = UBIFS_CS_NODE;
332 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
333 kfree(cs);
334 if (err)
335 return err;
336
337 ubifs_msg(c, "default file-system created");
338 return 0;
339 }
340 #endif
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 */
validate_sb(struct ubifs_info * c,struct ubifs_sb_node * sup)352 static 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
470 failed:
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 */
ubifs_read_sb_node(struct ubifs_info * c)484 struct 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 */
ubifs_write_sb_node(struct ubifs_info * c,struct ubifs_sb_node * sup)510 int 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 */
ubifs_read_superblock(struct ubifs_info * c)526 int 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 #ifndef __UBOOT__
533 err = create_default_filesystem(c);
534 if (err)
535 return err;
536 #else
537 printf("No UBIFS filesystem found!\n");
538 return -1;
539 #endif
540 }
541
542 sup = ubifs_read_sb_node(c);
543 if (IS_ERR(sup))
544 return PTR_ERR(sup);
545
546 c->fmt_version = le32_to_cpu(sup->fmt_version);
547 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
548
549 /*
550 * The software supports all previous versions but not future versions,
551 * due to the unavailability of time-travelling equipment.
552 */
553 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
554 ubifs_assert(!c->ro_media || c->ro_mount);
555 if (!c->ro_mount ||
556 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
557 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
558 c->fmt_version, c->ro_compat_version,
559 UBIFS_FORMAT_VERSION,
560 UBIFS_RO_COMPAT_VERSION);
561 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
562 ubifs_msg(c, "only R/O mounting is possible");
563 err = -EROFS;
564 } else
565 err = -EINVAL;
566 goto out;
567 }
568
569 /*
570 * The FS is mounted R/O, and the media format is
571 * R/O-compatible with the UBIFS implementation, so we can
572 * mount.
573 */
574 c->rw_incompat = 1;
575 }
576
577 if (c->fmt_version < 3) {
578 ubifs_err(c, "on-flash format version %d is not supported",
579 c->fmt_version);
580 err = -EINVAL;
581 goto out;
582 }
583
584 switch (sup->key_hash) {
585 case UBIFS_KEY_HASH_R5:
586 c->key_hash = key_r5_hash;
587 c->key_hash_type = UBIFS_KEY_HASH_R5;
588 break;
589
590 case UBIFS_KEY_HASH_TEST:
591 c->key_hash = key_test_hash;
592 c->key_hash_type = UBIFS_KEY_HASH_TEST;
593 break;
594 };
595
596 c->key_fmt = sup->key_fmt;
597
598 switch (c->key_fmt) {
599 case UBIFS_SIMPLE_KEY_FMT:
600 c->key_len = UBIFS_SK_LEN;
601 break;
602 default:
603 ubifs_err(c, "unsupported key format");
604 err = -EINVAL;
605 goto out;
606 }
607
608 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
609 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
610 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
611 c->log_lebs = le32_to_cpu(sup->log_lebs);
612 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
613 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
614 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
615 c->fanout = le32_to_cpu(sup->fanout);
616 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
617 c->rp_size = le64_to_cpu(sup->rp_size);
618 #ifndef __UBOOT__
619 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
620 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
621 #else
622 c->rp_uid.val = le32_to_cpu(sup->rp_uid);
623 c->rp_gid.val = le32_to_cpu(sup->rp_gid);
624 #endif
625 sup_flags = le32_to_cpu(sup->flags);
626 if (!c->mount_opts.override_compr)
627 c->default_compr = le16_to_cpu(sup->default_compr);
628
629 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
630 memcpy(&c->uuid, &sup->uuid, 16);
631 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
632 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
633
634 /* Automatically increase file system size to the maximum size */
635 c->old_leb_cnt = c->leb_cnt;
636 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
637 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
638 if (c->ro_mount)
639 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
640 c->old_leb_cnt, c->leb_cnt);
641 #ifndef __UBOOT__
642 else {
643 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
644 c->old_leb_cnt, c->leb_cnt);
645 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
646 err = ubifs_write_sb_node(c, sup);
647 if (err)
648 goto out;
649 c->old_leb_cnt = c->leb_cnt;
650 }
651 #endif
652 }
653
654 c->log_bytes = (long long)c->log_lebs * c->leb_size;
655 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
656 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
657 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
658 c->orph_first = c->lpt_last + 1;
659 c->orph_last = c->orph_first + c->orph_lebs - 1;
660 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
661 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
662 c->main_first = c->leb_cnt - c->main_lebs;
663
664 err = validate_sb(c, sup);
665 out:
666 kfree(sup);
667 return err;
668 }
669
670 /**
671 * fixup_leb - fixup/unmap an LEB containing free space.
672 * @c: UBIFS file-system description object
673 * @lnum: the LEB number to fix up
674 * @len: number of used bytes in LEB (starting at offset 0)
675 *
676 * This function reads the contents of the given LEB number @lnum, then fixes
677 * it up, so that empty min. I/O units in the end of LEB are actually erased on
678 * flash (rather than being just all-0xff real data). If the LEB is completely
679 * empty, it is simply unmapped.
680 */
fixup_leb(struct ubifs_info * c,int lnum,int len)681 static int fixup_leb(struct ubifs_info *c, int lnum, int len)
682 {
683 int err;
684
685 ubifs_assert(len >= 0);
686 ubifs_assert(len % c->min_io_size == 0);
687 ubifs_assert(len < c->leb_size);
688
689 if (len == 0) {
690 dbg_mnt("unmap empty LEB %d", lnum);
691 return ubifs_leb_unmap(c, lnum);
692 }
693
694 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
695 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
696 if (err)
697 return err;
698
699 return ubifs_leb_change(c, lnum, c->sbuf, len);
700 }
701
702 /**
703 * fixup_free_space - find & remap all LEBs containing free space.
704 * @c: UBIFS file-system description object
705 *
706 * This function walks through all LEBs in the filesystem and fiexes up those
707 * containing free/empty space.
708 */
fixup_free_space(struct ubifs_info * c)709 static int fixup_free_space(struct ubifs_info *c)
710 {
711 int lnum, err = 0;
712 struct ubifs_lprops *lprops;
713
714 ubifs_get_lprops(c);
715
716 /* Fixup LEBs in the master area */
717 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
718 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
719 if (err)
720 goto out;
721 }
722
723 /* Unmap unused log LEBs */
724 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
725 while (lnum != c->ltail_lnum) {
726 err = fixup_leb(c, lnum, 0);
727 if (err)
728 goto out;
729 lnum = ubifs_next_log_lnum(c, lnum);
730 }
731
732 /*
733 * Fixup the log head which contains the only a CS node at the
734 * beginning.
735 */
736 err = fixup_leb(c, c->lhead_lnum,
737 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
738 if (err)
739 goto out;
740
741 /* Fixup LEBs in the LPT area */
742 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
743 int free = c->ltab[lnum - c->lpt_first].free;
744
745 if (free > 0) {
746 err = fixup_leb(c, lnum, c->leb_size - free);
747 if (err)
748 goto out;
749 }
750 }
751
752 /* Unmap LEBs in the orphans area */
753 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
754 err = fixup_leb(c, lnum, 0);
755 if (err)
756 goto out;
757 }
758
759 /* Fixup LEBs in the main area */
760 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
761 lprops = ubifs_lpt_lookup(c, lnum);
762 if (IS_ERR(lprops)) {
763 err = PTR_ERR(lprops);
764 goto out;
765 }
766
767 if (lprops->free > 0) {
768 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
769 if (err)
770 goto out;
771 }
772 }
773
774 out:
775 ubifs_release_lprops(c);
776 return err;
777 }
778
779 /**
780 * ubifs_fixup_free_space - find & fix all LEBs with free space.
781 * @c: UBIFS file-system description object
782 *
783 * This function fixes up LEBs containing free space on first mount, if the
784 * appropriate flag was set when the FS was created. Each LEB with one or more
785 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
786 * the free space is actually erased. E.g., this is necessary for some NAND
787 * chips, since the free space may have been programmed like real "0xff" data
788 * (generating a non-0xff ECC), causing future writes to the not-really-erased
789 * NAND pages to behave badly. After the space is fixed up, the superblock flag
790 * is cleared, so that this is skipped for all future mounts.
791 */
ubifs_fixup_free_space(struct ubifs_info * c)792 int ubifs_fixup_free_space(struct ubifs_info *c)
793 {
794 int err;
795 struct ubifs_sb_node *sup;
796
797 ubifs_assert(c->space_fixup);
798 ubifs_assert(!c->ro_mount);
799
800 ubifs_msg(c, "start fixing up free space");
801
802 err = fixup_free_space(c);
803 if (err)
804 return err;
805
806 sup = ubifs_read_sb_node(c);
807 if (IS_ERR(sup))
808 return PTR_ERR(sup);
809
810 /* Free-space fixup is no longer required */
811 c->space_fixup = 0;
812 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
813
814 err = ubifs_write_sb_node(c, sup);
815 kfree(sup);
816 if (err)
817 return err;
818
819 ubifs_msg(c, "free space fixup complete");
820 return err;
821 }
822