2 * This file is part of UBIFS.
4 * Copyright (C) 2006-2008 Nokia Corporation.
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.
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
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
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
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.
30 #include <linux/slab.h>
31 #include <linux/math64.h>
32 #include <linux/uuid.h>
35 * Default journal size in logical eraseblocks as a percent of total
38 #define DEFAULT_JNL_PERCENT 5
40 /* Default maximum journal size in bytes */
41 #define DEFAULT_MAX_JNL (32*1024*1024)
43 /* Default indexing tree fanout */
44 #define DEFAULT_FANOUT 8
46 /* Default number of data journal heads */
47 #define DEFAULT_JHEADS_CNT 1
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
54 /* Default number of LEB numbers in LPT's save table */
55 #define DEFAULT_LSAVE_CNT 256
57 /* Default reserved pool size as a percent of maximum free space */
58 #define DEFAULT_RP_PERCENT 5
60 /* The default maximum size of reserved pool in bytes */
61 #define DEFAULT_MAX_RP_SIZE (5*1024*1024)
63 /* Default time granularity in nanoseconds */
64 #define DEFAULT_TIME_GRAN 1000000000
66 static int get_default_compressor(struct ubifs_info
*c
)
68 if (ubifs_compr_present(c
, UBIFS_COMPR_LZO
))
69 return UBIFS_COMPR_LZO
;
71 if (ubifs_compr_present(c
, UBIFS_COMPR_ZLIB
))
72 return UBIFS_COMPR_ZLIB
;
74 return UBIFS_COMPR_NONE
;
78 * create_default_filesystem - format empty UBI volume.
79 * @c: UBIFS file-system description object
81 * This function creates default empty file-system. Returns zero in case of
82 * success and a negative error code in case of failure.
84 static int create_default_filesystem(struct ubifs_info
*c
)
86 struct ubifs_sb_node
*sup
;
87 struct ubifs_mst_node
*mst
;
88 struct ubifs_idx_node
*idx
;
89 struct ubifs_branch
*br
;
90 struct ubifs_ino_node
*ino
;
91 struct ubifs_cs_node
*cs
;
93 int err
, tmp
, jnl_lebs
, log_lebs
, max_buds
, main_lebs
, main_first
;
94 int lpt_lebs
, lpt_first
, orph_lebs
, big_lpt
, ino_waste
, sup_flags
= 0;
95 int min_leb_cnt
= UBIFS_MIN_LEB_CNT
;
97 long long tmp64
, main_bytes
;
100 struct timespec64 ts
;
101 u8 hash
[UBIFS_HASH_ARR_SZ
];
102 u8 hash_lpt
[UBIFS_HASH_ARR_SZ
];
104 /* Some functions called from here depend on the @c->key_len filed */
105 c
->key_len
= UBIFS_SK_LEN
;
108 * First of all, we have to calculate default file-system geometry -
109 * log size, journal size, etc.
111 if (c
->leb_cnt
< 0x7FFFFFFF / DEFAULT_JNL_PERCENT
)
112 /* We can first multiply then divide and have no overflow */
113 jnl_lebs
= c
->leb_cnt
* DEFAULT_JNL_PERCENT
/ 100;
115 jnl_lebs
= (c
->leb_cnt
/ 100) * DEFAULT_JNL_PERCENT
;
117 if (jnl_lebs
< UBIFS_MIN_JNL_LEBS
)
118 jnl_lebs
= UBIFS_MIN_JNL_LEBS
;
119 if (jnl_lebs
* c
->leb_size
> DEFAULT_MAX_JNL
)
120 jnl_lebs
= DEFAULT_MAX_JNL
/ c
->leb_size
;
123 * The log should be large enough to fit reference nodes for all bud
124 * LEBs. Because buds do not have to start from the beginning of LEBs
125 * (half of the LEB may contain committed data), the log should
126 * generally be larger, make it twice as large.
128 tmp
= 2 * (c
->ref_node_alsz
* jnl_lebs
) + c
->leb_size
- 1;
129 log_lebs
= tmp
/ c
->leb_size
;
130 /* Plus one LEB reserved for commit */
132 if (c
->leb_cnt
- min_leb_cnt
> 8) {
133 /* And some extra space to allow writes while committing */
138 max_buds
= jnl_lebs
- log_lebs
;
139 if (max_buds
< UBIFS_MIN_BUD_LEBS
)
140 max_buds
= UBIFS_MIN_BUD_LEBS
;
143 * Orphan nodes are stored in a separate area. One node can store a lot
144 * of orphan inode numbers, but when new orphan comes we just add a new
145 * orphan node. At some point the nodes are consolidated into one
148 orph_lebs
= UBIFS_MIN_ORPH_LEBS
;
149 if (c
->leb_cnt
- min_leb_cnt
> 1)
151 * For debugging purposes it is better to have at least 2
152 * orphan LEBs, because the orphan subsystem would need to do
153 * consolidations and would be stressed more.
157 main_lebs
= c
->leb_cnt
- UBIFS_SB_LEBS
- UBIFS_MST_LEBS
- log_lebs
;
158 main_lebs
-= orph_lebs
;
160 lpt_first
= UBIFS_LOG_LNUM
+ log_lebs
;
161 c
->lsave_cnt
= DEFAULT_LSAVE_CNT
;
162 c
->max_leb_cnt
= c
->leb_cnt
;
163 err
= ubifs_create_dflt_lpt(c
, &main_lebs
, lpt_first
, &lpt_lebs
,
168 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first
,
169 lpt_first
+ lpt_lebs
- 1);
171 main_first
= c
->leb_cnt
- main_lebs
;
173 sup
= kzalloc(ALIGN(UBIFS_SB_NODE_SZ
, c
->min_io_size
), GFP_KERNEL
);
174 mst
= kzalloc(c
->mst_node_alsz
, GFP_KERNEL
);
175 idx_node_size
= ubifs_idx_node_sz(c
, 1);
176 idx
= kzalloc(ALIGN(tmp
, c
->min_io_size
), GFP_KERNEL
);
177 ino
= kzalloc(ALIGN(UBIFS_INO_NODE_SZ
, c
->min_io_size
), GFP_KERNEL
);
178 cs
= kzalloc(ALIGN(UBIFS_CS_NODE_SZ
, c
->min_io_size
), GFP_KERNEL
);
180 if (!sup
|| !mst
|| !idx
|| !ino
|| !cs
) {
185 /* Create default superblock */
187 tmp64
= (long long)max_buds
* c
->leb_size
;
189 sup_flags
|= UBIFS_FLG_BIGLPT
;
190 sup_flags
|= UBIFS_FLG_DOUBLE_HASH
;
192 if (ubifs_authenticated(c
)) {
193 sup_flags
|= UBIFS_FLG_AUTHENTICATION
;
194 sup
->hash_algo
= cpu_to_le16(c
->auth_hash_algo
);
195 err
= ubifs_hmac_wkm(c
, sup
->hmac_wkm
);
199 sup
->hash_algo
= 0xffff;
202 sup
->ch
.node_type
= UBIFS_SB_NODE
;
203 sup
->key_hash
= UBIFS_KEY_HASH_R5
;
204 sup
->flags
= cpu_to_le32(sup_flags
);
205 sup
->min_io_size
= cpu_to_le32(c
->min_io_size
);
206 sup
->leb_size
= cpu_to_le32(c
->leb_size
);
207 sup
->leb_cnt
= cpu_to_le32(c
->leb_cnt
);
208 sup
->max_leb_cnt
= cpu_to_le32(c
->max_leb_cnt
);
209 sup
->max_bud_bytes
= cpu_to_le64(tmp64
);
210 sup
->log_lebs
= cpu_to_le32(log_lebs
);
211 sup
->lpt_lebs
= cpu_to_le32(lpt_lebs
);
212 sup
->orph_lebs
= cpu_to_le32(orph_lebs
);
213 sup
->jhead_cnt
= cpu_to_le32(DEFAULT_JHEADS_CNT
);
214 sup
->fanout
= cpu_to_le32(DEFAULT_FANOUT
);
215 sup
->lsave_cnt
= cpu_to_le32(c
->lsave_cnt
);
216 sup
->fmt_version
= cpu_to_le32(UBIFS_FORMAT_VERSION
);
217 sup
->time_gran
= cpu_to_le32(DEFAULT_TIME_GRAN
);
218 if (c
->mount_opts
.override_compr
)
219 sup
->default_compr
= cpu_to_le16(c
->mount_opts
.compr_type
);
221 sup
->default_compr
= cpu_to_le16(get_default_compressor(c
));
223 generate_random_uuid(sup
->uuid
);
225 main_bytes
= (long long)main_lebs
* c
->leb_size
;
226 tmp64
= div_u64(main_bytes
* DEFAULT_RP_PERCENT
, 100);
227 if (tmp64
> DEFAULT_MAX_RP_SIZE
)
228 tmp64
= DEFAULT_MAX_RP_SIZE
;
229 sup
->rp_size
= cpu_to_le64(tmp64
);
230 sup
->ro_compat_version
= cpu_to_le32(UBIFS_RO_COMPAT_VERSION
);
232 dbg_gen("default superblock created at LEB 0:0");
234 /* Create default master node */
236 mst
->ch
.node_type
= UBIFS_MST_NODE
;
237 mst
->log_lnum
= cpu_to_le32(UBIFS_LOG_LNUM
);
238 mst
->highest_inum
= cpu_to_le64(UBIFS_FIRST_INO
);
240 mst
->root_lnum
= cpu_to_le32(main_first
+ DEFAULT_IDX_LEB
);
242 tmp
= ubifs_idx_node_sz(c
, 1);
243 mst
->root_len
= cpu_to_le32(tmp
);
244 mst
->gc_lnum
= cpu_to_le32(main_first
+ DEFAULT_GC_LEB
);
245 mst
->ihead_lnum
= cpu_to_le32(main_first
+ DEFAULT_IDX_LEB
);
246 mst
->ihead_offs
= cpu_to_le32(ALIGN(tmp
, c
->min_io_size
));
247 mst
->index_size
= cpu_to_le64(ALIGN(tmp
, 8));
248 mst
->lpt_lnum
= cpu_to_le32(c
->lpt_lnum
);
249 mst
->lpt_offs
= cpu_to_le32(c
->lpt_offs
);
250 mst
->nhead_lnum
= cpu_to_le32(c
->nhead_lnum
);
251 mst
->nhead_offs
= cpu_to_le32(c
->nhead_offs
);
252 mst
->ltab_lnum
= cpu_to_le32(c
->ltab_lnum
);
253 mst
->ltab_offs
= cpu_to_le32(c
->ltab_offs
);
254 mst
->lsave_lnum
= cpu_to_le32(c
->lsave_lnum
);
255 mst
->lsave_offs
= cpu_to_le32(c
->lsave_offs
);
256 mst
->lscan_lnum
= cpu_to_le32(main_first
);
257 mst
->empty_lebs
= cpu_to_le32(main_lebs
- 2);
258 mst
->idx_lebs
= cpu_to_le32(1);
259 mst
->leb_cnt
= cpu_to_le32(c
->leb_cnt
);
260 ubifs_copy_hash(c
, hash_lpt
, mst
->hash_lpt
);
262 /* Calculate lprops statistics */
264 tmp64
-= ALIGN(ubifs_idx_node_sz(c
, 1), c
->min_io_size
);
265 tmp64
-= ALIGN(UBIFS_INO_NODE_SZ
, c
->min_io_size
);
266 mst
->total_free
= cpu_to_le64(tmp64
);
268 tmp64
= ALIGN(ubifs_idx_node_sz(c
, 1), c
->min_io_size
);
269 ino_waste
= ALIGN(UBIFS_INO_NODE_SZ
, c
->min_io_size
) -
272 tmp64
-= ALIGN(ubifs_idx_node_sz(c
, 1), 8);
273 mst
->total_dirty
= cpu_to_le64(tmp64
);
275 /* The indexing LEB does not contribute to dark space */
276 tmp64
= ((long long)(c
->main_lebs
- 1) * c
->dark_wm
);
277 mst
->total_dark
= cpu_to_le64(tmp64
);
279 mst
->total_used
= cpu_to_le64(UBIFS_INO_NODE_SZ
);
281 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM
);
283 /* Create the root indexing node */
285 c
->key_fmt
= UBIFS_SIMPLE_KEY_FMT
;
286 c
->key_hash
= key_r5_hash
;
288 idx
->ch
.node_type
= UBIFS_IDX_NODE
;
289 idx
->child_cnt
= cpu_to_le16(1);
290 ino_key_init(c
, &key
, UBIFS_ROOT_INO
);
291 br
= ubifs_idx_branch(c
, idx
, 0);
292 key_write_idx(c
, &key
, &br
->key
);
293 br
->lnum
= cpu_to_le32(main_first
+ DEFAULT_DATA_LEB
);
294 br
->len
= cpu_to_le32(UBIFS_INO_NODE_SZ
);
296 dbg_gen("default root indexing node created LEB %d:0",
297 main_first
+ DEFAULT_IDX_LEB
);
299 /* Create default root inode */
301 ino_key_init_flash(c
, &ino
->key
, UBIFS_ROOT_INO
);
302 ino
->ch
.node_type
= UBIFS_INO_NODE
;
303 ino
->creat_sqnum
= cpu_to_le64(++c
->max_sqnum
);
304 ino
->nlink
= cpu_to_le32(2);
306 ktime_get_real_ts64(&ts
);
307 ts
= timespec64_trunc(ts
, DEFAULT_TIME_GRAN
);
308 tmp_le64
= cpu_to_le64(ts
.tv_sec
);
309 ino
->atime_sec
= tmp_le64
;
310 ino
->ctime_sec
= tmp_le64
;
311 ino
->mtime_sec
= tmp_le64
;
312 tmp_le32
= cpu_to_le32(ts
.tv_nsec
);
313 ino
->atime_nsec
= tmp_le32
;
314 ino
->ctime_nsec
= tmp_le32
;
315 ino
->mtime_nsec
= tmp_le32
;
316 ino
->mode
= cpu_to_le32(S_IFDIR
| S_IRUGO
| S_IWUSR
| S_IXUGO
);
317 ino
->size
= cpu_to_le64(UBIFS_INO_NODE_SZ
);
319 /* Set compression enabled by default */
320 ino
->flags
= cpu_to_le32(UBIFS_COMPR_FL
);
322 dbg_gen("root inode created at LEB %d:0",
323 main_first
+ DEFAULT_DATA_LEB
);
326 * The first node in the log has to be the commit start node. This is
327 * always the case during normal file-system operation. Write a fake
328 * commit start node to the log.
331 cs
->ch
.node_type
= UBIFS_CS_NODE
;
333 err
= ubifs_write_node_hmac(c
, sup
, UBIFS_SB_NODE_SZ
, 0, 0,
334 offsetof(struct ubifs_sb_node
, hmac
));
338 err
= ubifs_write_node(c
, ino
, UBIFS_INO_NODE_SZ
,
339 main_first
+ DEFAULT_DATA_LEB
, 0);
343 ubifs_node_calc_hash(c
, ino
, hash
);
344 ubifs_copy_hash(c
, hash
, ubifs_branch_hash(c
, br
));
346 err
= ubifs_write_node(c
, idx
, idx_node_size
, main_first
+ DEFAULT_IDX_LEB
, 0);
350 ubifs_node_calc_hash(c
, idx
, hash
);
351 ubifs_copy_hash(c
, hash
, mst
->hash_root_idx
);
353 err
= ubifs_write_node_hmac(c
, mst
, UBIFS_MST_NODE_SZ
, UBIFS_MST_LNUM
, 0,
354 offsetof(struct ubifs_mst_node
, hmac
));
358 err
= ubifs_write_node_hmac(c
, mst
, UBIFS_MST_NODE_SZ
, UBIFS_MST_LNUM
+ 1,
359 0, offsetof(struct ubifs_mst_node
, hmac
));
363 err
= ubifs_write_node(c
, cs
, UBIFS_CS_NODE_SZ
, UBIFS_LOG_LNUM
, 0);
367 ubifs_msg(c
, "default file-system created");
381 * validate_sb - validate superblock node.
382 * @c: UBIFS file-system description object
383 * @sup: superblock node
385 * This function validates superblock node @sup. Since most of data was read
386 * from the superblock and stored in @c, the function validates fields in @c
387 * instead. Returns zero in case of success and %-EINVAL in case of validation
390 static int validate_sb(struct ubifs_info
*c
, struct ubifs_sb_node
*sup
)
393 int err
= 1, min_leb_cnt
;
400 if (sup
->key_fmt
!= UBIFS_SIMPLE_KEY_FMT
) {
405 if (le32_to_cpu(sup
->min_io_size
) != c
->min_io_size
) {
406 ubifs_err(c
, "min. I/O unit mismatch: %d in superblock, %d real",
407 le32_to_cpu(sup
->min_io_size
), c
->min_io_size
);
411 if (le32_to_cpu(sup
->leb_size
) != c
->leb_size
) {
412 ubifs_err(c
, "LEB size mismatch: %d in superblock, %d real",
413 le32_to_cpu(sup
->leb_size
), c
->leb_size
);
417 if (c
->log_lebs
< UBIFS_MIN_LOG_LEBS
||
418 c
->lpt_lebs
< UBIFS_MIN_LPT_LEBS
||
419 c
->orph_lebs
< UBIFS_MIN_ORPH_LEBS
||
420 c
->main_lebs
< UBIFS_MIN_MAIN_LEBS
) {
426 * Calculate minimum allowed amount of main area LEBs. This is very
427 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
428 * have just read from the superblock.
430 min_leb_cnt
= UBIFS_SB_LEBS
+ UBIFS_MST_LEBS
+ c
->log_lebs
;
431 min_leb_cnt
+= c
->lpt_lebs
+ c
->orph_lebs
+ c
->jhead_cnt
+ 6;
433 if (c
->leb_cnt
< min_leb_cnt
|| c
->leb_cnt
> c
->vi
.size
) {
434 ubifs_err(c
, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
435 c
->leb_cnt
, c
->vi
.size
, min_leb_cnt
);
439 if (c
->max_leb_cnt
< c
->leb_cnt
) {
440 ubifs_err(c
, "max. LEB count %d less than LEB count %d",
441 c
->max_leb_cnt
, c
->leb_cnt
);
445 if (c
->main_lebs
< UBIFS_MIN_MAIN_LEBS
) {
446 ubifs_err(c
, "too few main LEBs count %d, must be at least %d",
447 c
->main_lebs
, UBIFS_MIN_MAIN_LEBS
);
451 max_bytes
= (long long)c
->leb_size
* UBIFS_MIN_BUD_LEBS
;
452 if (c
->max_bud_bytes
< max_bytes
) {
453 ubifs_err(c
, "too small journal (%lld bytes), must be at least %lld bytes",
454 c
->max_bud_bytes
, max_bytes
);
458 max_bytes
= (long long)c
->leb_size
* c
->main_lebs
;
459 if (c
->max_bud_bytes
> max_bytes
) {
460 ubifs_err(c
, "too large journal size (%lld bytes), only %lld bytes available in the main area",
461 c
->max_bud_bytes
, max_bytes
);
465 if (c
->jhead_cnt
< NONDATA_JHEADS_CNT
+ 1 ||
466 c
->jhead_cnt
> NONDATA_JHEADS_CNT
+ UBIFS_MAX_JHEADS
) {
471 if (c
->fanout
< UBIFS_MIN_FANOUT
||
472 ubifs_idx_node_sz(c
, c
->fanout
) > c
->leb_size
) {
477 if (c
->lsave_cnt
< 0 || (c
->lsave_cnt
> DEFAULT_LSAVE_CNT
&&
478 c
->lsave_cnt
> c
->max_leb_cnt
- UBIFS_SB_LEBS
- UBIFS_MST_LEBS
-
479 c
->log_lebs
- c
->lpt_lebs
- c
->orph_lebs
)) {
484 if (UBIFS_SB_LEBS
+ UBIFS_MST_LEBS
+ c
->log_lebs
+ c
->lpt_lebs
+
485 c
->orph_lebs
+ c
->main_lebs
!= c
->leb_cnt
) {
490 if (c
->default_compr
>= UBIFS_COMPR_TYPES_CNT
) {
495 if (c
->rp_size
< 0 || max_bytes
< c
->rp_size
) {
500 if (le32_to_cpu(sup
->time_gran
) > 1000000000 ||
501 le32_to_cpu(sup
->time_gran
) < 1) {
506 if (!c
->double_hash
&& c
->fmt_version
>= 5) {
511 if (c
->encrypted
&& c
->fmt_version
< 5) {
519 ubifs_err(c
, "bad superblock, error %d", err
);
520 ubifs_dump_node(c
, sup
);
525 * ubifs_read_sb_node - read superblock node.
526 * @c: UBIFS file-system description object
528 * This function returns a pointer to the superblock node or a negative error
529 * code. Note, the user of this function is responsible of kfree()'ing the
530 * returned superblock buffer.
532 static struct ubifs_sb_node
*ubifs_read_sb_node(struct ubifs_info
*c
)
534 struct ubifs_sb_node
*sup
;
537 sup
= kmalloc(ALIGN(UBIFS_SB_NODE_SZ
, c
->min_io_size
), GFP_NOFS
);
539 return ERR_PTR(-ENOMEM
);
541 err
= ubifs_read_node(c
, sup
, UBIFS_SB_NODE
, UBIFS_SB_NODE_SZ
,
551 static int authenticate_sb_node(struct ubifs_info
*c
,
552 const struct ubifs_sb_node
*sup
)
554 unsigned int sup_flags
= le32_to_cpu(sup
->flags
);
555 u8 hmac_wkm
[UBIFS_HMAC_ARR_SZ
];
556 int authenticated
= !!(sup_flags
& UBIFS_FLG_AUTHENTICATION
);
560 if (c
->authenticated
&& !authenticated
) {
561 ubifs_err(c
, "authenticated FS forced, but found FS without authentication");
565 if (!c
->authenticated
&& authenticated
) {
566 ubifs_err(c
, "authenticated FS found, but no key given");
570 ubifs_msg(c
, "Mounting in %sauthenticated mode",
571 c
->authenticated
? "" : "un");
573 if (!c
->authenticated
)
576 if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION
))
579 hash_algo
= le16_to_cpu(sup
->hash_algo
);
580 if (hash_algo
>= HASH_ALGO__LAST
) {
581 ubifs_err(c
, "superblock uses unknown hash algo %d",
586 if (strcmp(hash_algo_name
[hash_algo
], c
->auth_hash_name
)) {
587 ubifs_err(c
, "This filesystem uses %s for hashing,"
588 " but %s is specified", hash_algo_name
[hash_algo
],
593 err
= ubifs_hmac_wkm(c
, hmac_wkm
);
597 if (ubifs_check_hmac(c
, hmac_wkm
, sup
->hmac_wkm
)) {
598 ubifs_err(c
, "provided key does not fit");
602 err
= ubifs_node_verify_hmac(c
, sup
, sizeof(*sup
),
603 offsetof(struct ubifs_sb_node
, hmac
));
605 ubifs_err(c
, "Failed to authenticate superblock: %d", err
);
611 * ubifs_write_sb_node - write superblock node.
612 * @c: UBIFS file-system description object
613 * @sup: superblock node read with 'ubifs_read_sb_node()'
615 * This function returns %0 on success and a negative error code on failure.
617 int ubifs_write_sb_node(struct ubifs_info
*c
, struct ubifs_sb_node
*sup
)
619 int len
= ALIGN(UBIFS_SB_NODE_SZ
, c
->min_io_size
);
622 err
= ubifs_prepare_node_hmac(c
, sup
, UBIFS_SB_NODE_SZ
,
623 offsetof(struct ubifs_sb_node
, hmac
), 1);
627 return ubifs_leb_change(c
, UBIFS_SB_LNUM
, sup
, len
);
631 * ubifs_read_superblock - read superblock.
632 * @c: UBIFS file-system description object
634 * This function finds, reads and checks the superblock. If an empty UBI volume
635 * is being mounted, this function creates default superblock. Returns zero in
636 * case of success, and a negative error code in case of failure.
638 int ubifs_read_superblock(struct ubifs_info
*c
)
641 struct ubifs_sb_node
*sup
;
644 err
= create_default_filesystem(c
);
649 sup
= ubifs_read_sb_node(c
);
655 c
->fmt_version
= le32_to_cpu(sup
->fmt_version
);
656 c
->ro_compat_version
= le32_to_cpu(sup
->ro_compat_version
);
659 * The software supports all previous versions but not future versions,
660 * due to the unavailability of time-travelling equipment.
662 if (c
->fmt_version
> UBIFS_FORMAT_VERSION
) {
663 ubifs_assert(c
, !c
->ro_media
|| c
->ro_mount
);
665 c
->ro_compat_version
> UBIFS_RO_COMPAT_VERSION
) {
666 ubifs_err(c
, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
667 c
->fmt_version
, c
->ro_compat_version
,
668 UBIFS_FORMAT_VERSION
,
669 UBIFS_RO_COMPAT_VERSION
);
670 if (c
->ro_compat_version
<= UBIFS_RO_COMPAT_VERSION
) {
671 ubifs_msg(c
, "only R/O mounting is possible");
679 * The FS is mounted R/O, and the media format is
680 * R/O-compatible with the UBIFS implementation, so we can
686 if (c
->fmt_version
< 3) {
687 ubifs_err(c
, "on-flash format version %d is not supported",
693 switch (sup
->key_hash
) {
694 case UBIFS_KEY_HASH_R5
:
695 c
->key_hash
= key_r5_hash
;
696 c
->key_hash_type
= UBIFS_KEY_HASH_R5
;
699 case UBIFS_KEY_HASH_TEST
:
700 c
->key_hash
= key_test_hash
;
701 c
->key_hash_type
= UBIFS_KEY_HASH_TEST
;
705 c
->key_fmt
= sup
->key_fmt
;
707 switch (c
->key_fmt
) {
708 case UBIFS_SIMPLE_KEY_FMT
:
709 c
->key_len
= UBIFS_SK_LEN
;
712 ubifs_err(c
, "unsupported key format");
717 c
->leb_cnt
= le32_to_cpu(sup
->leb_cnt
);
718 c
->max_leb_cnt
= le32_to_cpu(sup
->max_leb_cnt
);
719 c
->max_bud_bytes
= le64_to_cpu(sup
->max_bud_bytes
);
720 c
->log_lebs
= le32_to_cpu(sup
->log_lebs
);
721 c
->lpt_lebs
= le32_to_cpu(sup
->lpt_lebs
);
722 c
->orph_lebs
= le32_to_cpu(sup
->orph_lebs
);
723 c
->jhead_cnt
= le32_to_cpu(sup
->jhead_cnt
) + NONDATA_JHEADS_CNT
;
724 c
->fanout
= le32_to_cpu(sup
->fanout
);
725 c
->lsave_cnt
= le32_to_cpu(sup
->lsave_cnt
);
726 c
->rp_size
= le64_to_cpu(sup
->rp_size
);
727 c
->rp_uid
= make_kuid(&init_user_ns
, le32_to_cpu(sup
->rp_uid
));
728 c
->rp_gid
= make_kgid(&init_user_ns
, le32_to_cpu(sup
->rp_gid
));
729 sup_flags
= le32_to_cpu(sup
->flags
);
730 if (!c
->mount_opts
.override_compr
)
731 c
->default_compr
= le16_to_cpu(sup
->default_compr
);
733 c
->vfs_sb
->s_time_gran
= le32_to_cpu(sup
->time_gran
);
734 memcpy(&c
->uuid
, &sup
->uuid
, 16);
735 c
->big_lpt
= !!(sup_flags
& UBIFS_FLG_BIGLPT
);
736 c
->space_fixup
= !!(sup_flags
& UBIFS_FLG_SPACE_FIXUP
);
737 c
->double_hash
= !!(sup_flags
& UBIFS_FLG_DOUBLE_HASH
);
738 c
->encrypted
= !!(sup_flags
& UBIFS_FLG_ENCRYPTION
);
740 err
= authenticate_sb_node(c
, sup
);
744 if ((sup_flags
& ~UBIFS_FLG_MASK
) != 0) {
745 ubifs_err(c
, "Unknown feature flags found: %#x",
746 sup_flags
& ~UBIFS_FLG_MASK
);
751 if (!IS_ENABLED(CONFIG_UBIFS_FS_ENCRYPTION
) && c
->encrypted
) {
752 ubifs_err(c
, "file system contains encrypted files but UBIFS"
753 " was built without crypto support.");
758 /* Automatically increase file system size to the maximum size */
759 c
->old_leb_cnt
= c
->leb_cnt
;
760 if (c
->leb_cnt
< c
->vi
.size
&& c
->leb_cnt
< c
->max_leb_cnt
) {
761 c
->leb_cnt
= min_t(int, c
->max_leb_cnt
, c
->vi
.size
);
763 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
764 c
->old_leb_cnt
, c
->leb_cnt
);
766 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
767 c
->old_leb_cnt
, c
->leb_cnt
);
768 sup
->leb_cnt
= cpu_to_le32(c
->leb_cnt
);
769 err
= ubifs_write_sb_node(c
, sup
);
772 c
->old_leb_cnt
= c
->leb_cnt
;
776 c
->log_bytes
= (long long)c
->log_lebs
* c
->leb_size
;
777 c
->log_last
= UBIFS_LOG_LNUM
+ c
->log_lebs
- 1;
778 c
->lpt_first
= UBIFS_LOG_LNUM
+ c
->log_lebs
;
779 c
->lpt_last
= c
->lpt_first
+ c
->lpt_lebs
- 1;
780 c
->orph_first
= c
->lpt_last
+ 1;
781 c
->orph_last
= c
->orph_first
+ c
->orph_lebs
- 1;
782 c
->main_lebs
= c
->leb_cnt
- UBIFS_SB_LEBS
- UBIFS_MST_LEBS
;
783 c
->main_lebs
-= c
->log_lebs
+ c
->lpt_lebs
+ c
->orph_lebs
;
784 c
->main_first
= c
->leb_cnt
- c
->main_lebs
;
786 err
= validate_sb(c
, sup
);
792 * fixup_leb - fixup/unmap an LEB containing free space.
793 * @c: UBIFS file-system description object
794 * @lnum: the LEB number to fix up
795 * @len: number of used bytes in LEB (starting at offset 0)
797 * This function reads the contents of the given LEB number @lnum, then fixes
798 * it up, so that empty min. I/O units in the end of LEB are actually erased on
799 * flash (rather than being just all-0xff real data). If the LEB is completely
800 * empty, it is simply unmapped.
802 static int fixup_leb(struct ubifs_info
*c
, int lnum
, int len
)
806 ubifs_assert(c
, len
>= 0);
807 ubifs_assert(c
, len
% c
->min_io_size
== 0);
808 ubifs_assert(c
, len
< c
->leb_size
);
811 dbg_mnt("unmap empty LEB %d", lnum
);
812 return ubifs_leb_unmap(c
, lnum
);
815 dbg_mnt("fixup LEB %d, data len %d", lnum
, len
);
816 err
= ubifs_leb_read(c
, lnum
, c
->sbuf
, 0, len
, 1);
820 return ubifs_leb_change(c
, lnum
, c
->sbuf
, len
);
824 * fixup_free_space - find & remap all LEBs containing free space.
825 * @c: UBIFS file-system description object
827 * This function walks through all LEBs in the filesystem and fiexes up those
828 * containing free/empty space.
830 static int fixup_free_space(struct ubifs_info
*c
)
833 struct ubifs_lprops
*lprops
;
837 /* Fixup LEBs in the master area */
838 for (lnum
= UBIFS_MST_LNUM
; lnum
< UBIFS_LOG_LNUM
; lnum
++) {
839 err
= fixup_leb(c
, lnum
, c
->mst_offs
+ c
->mst_node_alsz
);
844 /* Unmap unused log LEBs */
845 lnum
= ubifs_next_log_lnum(c
, c
->lhead_lnum
);
846 while (lnum
!= c
->ltail_lnum
) {
847 err
= fixup_leb(c
, lnum
, 0);
850 lnum
= ubifs_next_log_lnum(c
, lnum
);
854 * Fixup the log head which contains the only a CS node at the
857 err
= fixup_leb(c
, c
->lhead_lnum
,
858 ALIGN(UBIFS_CS_NODE_SZ
, c
->min_io_size
));
862 /* Fixup LEBs in the LPT area */
863 for (lnum
= c
->lpt_first
; lnum
<= c
->lpt_last
; lnum
++) {
864 int free
= c
->ltab
[lnum
- c
->lpt_first
].free
;
867 err
= fixup_leb(c
, lnum
, c
->leb_size
- free
);
873 /* Unmap LEBs in the orphans area */
874 for (lnum
= c
->orph_first
; lnum
<= c
->orph_last
; lnum
++) {
875 err
= fixup_leb(c
, lnum
, 0);
880 /* Fixup LEBs in the main area */
881 for (lnum
= c
->main_first
; lnum
< c
->leb_cnt
; lnum
++) {
882 lprops
= ubifs_lpt_lookup(c
, lnum
);
883 if (IS_ERR(lprops
)) {
884 err
= PTR_ERR(lprops
);
888 if (lprops
->free
> 0) {
889 err
= fixup_leb(c
, lnum
, c
->leb_size
- lprops
->free
);
896 ubifs_release_lprops(c
);
901 * ubifs_fixup_free_space - find & fix all LEBs with free space.
902 * @c: UBIFS file-system description object
904 * This function fixes up LEBs containing free space on first mount, if the
905 * appropriate flag was set when the FS was created. Each LEB with one or more
906 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
907 * the free space is actually erased. E.g., this is necessary for some NAND
908 * chips, since the free space may have been programmed like real "0xff" data
909 * (generating a non-0xff ECC), causing future writes to the not-really-erased
910 * NAND pages to behave badly. After the space is fixed up, the superblock flag
911 * is cleared, so that this is skipped for all future mounts.
913 int ubifs_fixup_free_space(struct ubifs_info
*c
)
916 struct ubifs_sb_node
*sup
= c
->sup_node
;
918 ubifs_assert(c
, c
->space_fixup
);
919 ubifs_assert(c
, !c
->ro_mount
);
921 ubifs_msg(c
, "start fixing up free space");
923 err
= fixup_free_space(c
);
927 /* Free-space fixup is no longer required */
929 sup
->flags
&= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP
);
931 err
= ubifs_write_sb_node(c
, sup
);
935 ubifs_msg(c
, "free space fixup complete");
939 int ubifs_enable_encryption(struct ubifs_info
*c
)
942 struct ubifs_sb_node
*sup
= c
->sup_node
;
944 if (!IS_ENABLED(CONFIG_UBIFS_FS_ENCRYPTION
))
950 if (c
->ro_mount
|| c
->ro_media
)
953 if (c
->fmt_version
< 5) {
954 ubifs_err(c
, "on-flash format version 5 is needed for encryption");
958 sup
->flags
|= cpu_to_le32(UBIFS_FLG_ENCRYPTION
);
960 err
= ubifs_write_sb_node(c
, sup
);