blob: 4c37607a958e037f7242b2f01ef9d69dd836512b [file] [log] [blame]
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/*
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"
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090030#include <linux/slab.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030031#include <linux/random.h>
Artem Bityutskiy4d61db42008-12-18 14:06:51 +020032#include <linux/math64.h>
Artem Bityutskiy1e517642008-07-14 19:08:37 +030033
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;
Artem Bityutskiy4d61db42008-12-18 14:06:51 +020085 long long tmp64, main_bytes;
Harvey Harrison0ecb9522008-10-24 10:52:57 -070086 __le64 tmp_le64;
Artem Bityutskiy1e517642008-07-14 19:08:37 +030087
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;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300133 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;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300140
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
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200163 tmp64 = (long long)max_buds * c->leb_size;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300164 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);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300182 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
Artem Bityutskiy553dea42008-11-01 14:57:49 +0200183 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);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300187
188 generate_random_uuid(sup->uuid);
189
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200190 main_bytes = (long long)main_lebs * c->leb_size;
191 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300192 if (tmp64 > DEFAULT_MAX_RP_SIZE)
193 tmp64 = DEFAULT_MAX_RP_SIZE;
194 sup->rp_size = cpu_to_le64(tmp64);
Artem Bityutskiy963f0cf2009-03-26 12:51:21 +0200195 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300196
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200197 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300198 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 */
srimugunthan dhandapani7606f852011-08-26 16:08:39 +0530248 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300249 mst->total_dark = cpu_to_le64(tmp64);
250
251 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
252
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200253 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300254 if (err) {
255 kfree(mst);
256 return err;
257 }
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200258 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
259 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300260 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);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200282 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300283 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);
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700300 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;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300304 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,
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200314 main_first + DEFAULT_DATA_LEB, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300315 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;
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200333 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300334 kfree(cs);
335
336 ubifs_msg("default file-system created");
337 return 0;
338}
339
340/**
341 * validate_sb - validate superblock node.
342 * @c: UBIFS file-system description object
343 * @sup: superblock node
344 *
345 * This function validates superblock node @sup. Since most of data was read
346 * from the superblock and stored in @c, the function validates fields in @c
347 * instead. Returns zero in case of success and %-EINVAL in case of validation
348 * failure.
349 */
350static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
351{
352 long long max_bytes;
353 int err = 1, min_leb_cnt;
354
355 if (!c->key_hash) {
356 err = 2;
357 goto failed;
358 }
359
360 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
361 err = 3;
362 goto failed;
363 }
364
365 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
366 ubifs_err("min. I/O unit mismatch: %d in superblock, %d real",
367 le32_to_cpu(sup->min_io_size), c->min_io_size);
368 goto failed;
369 }
370
371 if (le32_to_cpu(sup->leb_size) != c->leb_size) {
372 ubifs_err("LEB size mismatch: %d in superblock, %d real",
373 le32_to_cpu(sup->leb_size), c->leb_size);
374 goto failed;
375 }
376
377 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
378 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
379 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
380 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
381 err = 4;
382 goto failed;
383 }
384
385 /*
386 * Calculate minimum allowed amount of main area LEBs. This is very
387 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
388 * have just read from the superblock.
389 */
390 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
391 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
392
393 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
Artem Bityutskiy79fda512012-08-27 13:34:09 +0300394 ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
395 c->leb_cnt, c->vi.size, min_leb_cnt);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300396 goto failed;
397 }
398
399 if (c->max_leb_cnt < c->leb_cnt) {
400 ubifs_err("max. LEB count %d less than LEB count %d",
401 c->max_leb_cnt, c->leb_cnt);
402 goto failed;
403 }
404
405 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
Artem Bityutskiy5a1f36c2012-03-07 16:29:45 +0200406 ubifs_err("too few main LEBs count %d, must be at least %d",
407 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300408 goto failed;
409 }
410
Artem Bityutskiy5a1f36c2012-03-07 16:29:45 +0200411 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
412 if (c->max_bud_bytes < max_bytes) {
Artem Bityutskiy79fda512012-08-27 13:34:09 +0300413 ubifs_err("too small journal (%lld bytes), must be at least %lld bytes",
414 c->max_bud_bytes, max_bytes);
Artem Bityutskiy5a1f36c2012-03-07 16:29:45 +0200415 goto failed;
416 }
417
418 max_bytes = (long long)c->leb_size * c->main_lebs;
419 if (c->max_bud_bytes > max_bytes) {
Artem Bityutskiy79fda512012-08-27 13:34:09 +0300420 ubifs_err("too large journal size (%lld bytes), only %lld bytes available in the main area",
Artem Bityutskiy5a1f36c2012-03-07 16:29:45 +0200421 c->max_bud_bytes, max_bytes);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300422 goto failed;
423 }
424
425 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
426 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
427 err = 9;
428 goto failed;
429 }
430
431 if (c->fanout < UBIFS_MIN_FANOUT ||
432 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
433 err = 10;
434 goto failed;
435 }
436
437 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
438 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
439 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
440 err = 11;
441 goto failed;
442 }
443
444 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
445 c->orph_lebs + c->main_lebs != c->leb_cnt) {
446 err = 12;
447 goto failed;
448 }
449
450 if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
451 err = 13;
452 goto failed;
453 }
454
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300455 if (c->rp_size < 0 || max_bytes < c->rp_size) {
456 err = 14;
457 goto failed;
458 }
459
460 if (le32_to_cpu(sup->time_gran) > 1000000000 ||
461 le32_to_cpu(sup->time_gran) < 1) {
462 err = 15;
463 goto failed;
464 }
465
466 return 0;
467
468failed:
469 ubifs_err("bad superblock, error %d", err);
Artem Bityutskiyedf6be22012-05-16 19:15:56 +0300470 ubifs_dump_node(c, sup);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300471 return -EINVAL;
472}
473
474/**
475 * ubifs_read_sb_node - read superblock node.
476 * @c: UBIFS file-system description object
477 *
478 * This function returns a pointer to the superblock node or a negative error
Artem Bityutskiyeaeee242011-05-06 17:08:56 +0300479 * code. Note, the user of this function is responsible of kfree()'ing the
480 * returned superblock buffer.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300481 */
482struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
483{
484 struct ubifs_sb_node *sup;
485 int err;
486
487 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
488 if (!sup)
489 return ERR_PTR(-ENOMEM);
490
491 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
492 UBIFS_SB_LNUM, 0);
493 if (err) {
494 kfree(sup);
495 return ERR_PTR(err);
496 }
497
498 return sup;
499}
500
501/**
502 * ubifs_write_sb_node - write superblock node.
503 * @c: UBIFS file-system description object
504 * @sup: superblock node read with 'ubifs_read_sb_node()'
505 *
506 * This function returns %0 on success and a negative error code on failure.
507 */
508int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
509{
510 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
511
512 ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200513 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300514}
515
516/**
517 * ubifs_read_superblock - read superblock.
518 * @c: UBIFS file-system description object
519 *
520 * This function finds, reads and checks the superblock. If an empty UBI volume
521 * is being mounted, this function creates default superblock. Returns zero in
522 * case of success, and a negative error code in case of failure.
523 */
524int ubifs_read_superblock(struct ubifs_info *c)
525{
526 int err, sup_flags;
527 struct ubifs_sb_node *sup;
528
529 if (c->empty) {
530 err = create_default_filesystem(c);
531 if (err)
532 return err;
533 }
534
535 sup = ubifs_read_sb_node(c);
536 if (IS_ERR(sup))
537 return PTR_ERR(sup);
538
Artem Bityutskiy963f0cf2009-03-26 12:51:21 +0200539 c->fmt_version = le32_to_cpu(sup->fmt_version);
540 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
541
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300542 /*
543 * The software supports all previous versions but not future versions,
544 * due to the unavailability of time-travelling equipment.
545 */
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300546 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300547 ubifs_assert(!c->ro_media || c->ro_mount);
548 if (!c->ro_mount ||
Artem Bityutskiy963f0cf2009-03-26 12:51:21 +0200549 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
Artem Bityutskiy79fda512012-08-27 13:34:09 +0300550 ubifs_err("on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
551 c->fmt_version, c->ro_compat_version,
552 UBIFS_FORMAT_VERSION,
Artem Bityutskiy963f0cf2009-03-26 12:51:21 +0200553 UBIFS_RO_COMPAT_VERSION);
554 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
555 ubifs_msg("only R/O mounting is possible");
556 err = -EROFS;
557 } else
558 err = -EINVAL;
559 goto out;
560 }
561
562 /*
563 * The FS is mounted R/O, and the media format is
564 * R/O-compatible with the UBIFS implementation, so we can
565 * mount.
566 */
567 c->rw_incompat = 1;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300568 }
569
570 if (c->fmt_version < 3) {
571 ubifs_err("on-flash format version %d is not supported",
572 c->fmt_version);
573 err = -EINVAL;
574 goto out;
575 }
576
577 switch (sup->key_hash) {
578 case UBIFS_KEY_HASH_R5:
579 c->key_hash = key_r5_hash;
580 c->key_hash_type = UBIFS_KEY_HASH_R5;
581 break;
582
583 case UBIFS_KEY_HASH_TEST:
584 c->key_hash = key_test_hash;
585 c->key_hash_type = UBIFS_KEY_HASH_TEST;
586 break;
587 };
588
589 c->key_fmt = sup->key_fmt;
590
591 switch (c->key_fmt) {
592 case UBIFS_SIMPLE_KEY_FMT:
593 c->key_len = UBIFS_SK_LEN;
594 break;
595 default:
596 ubifs_err("unsupported key format");
597 err = -EINVAL;
598 goto out;
599 }
600
601 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
602 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
603 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
604 c->log_lebs = le32_to_cpu(sup->log_lebs);
605 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
606 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
607 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
608 c->fanout = le32_to_cpu(sup->fanout);
609 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300610 c->rp_size = le64_to_cpu(sup->rp_size);
Eric W. Biederman39241be2012-02-07 15:50:56 -0800611 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
612 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300613 sup_flags = le32_to_cpu(sup->flags);
Artem Bityutskiy553dea42008-11-01 14:57:49 +0200614 if (!c->mount_opts.override_compr)
615 c->default_compr = le16_to_cpu(sup->default_compr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300616
617 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300618 memcpy(&c->uuid, &sup->uuid, 16);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300619 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
Matthew L. Creech9f58d352011-05-05 16:33:20 -0400620 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300621
622 /* Automatically increase file system size to the maximum size */
623 c->old_leb_cnt = c->leb_cnt;
624 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
625 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300626 if (c->ro_mount)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300627 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
628 c->old_leb_cnt, c->leb_cnt);
629 else {
630 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
631 c->old_leb_cnt, c->leb_cnt);
632 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
633 err = ubifs_write_sb_node(c, sup);
634 if (err)
635 goto out;
636 c->old_leb_cnt = c->leb_cnt;
637 }
638 }
639
640 c->log_bytes = (long long)c->log_lebs * c->leb_size;
641 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
642 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
643 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
644 c->orph_first = c->lpt_last + 1;
645 c->orph_last = c->orph_first + c->orph_lebs - 1;
646 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
647 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
648 c->main_first = c->leb_cnt - c->main_lebs;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300649
650 err = validate_sb(c, sup);
651out:
652 kfree(sup);
653 return err;
654}
Matthew L. Creech6554a652011-05-06 18:58:22 -0400655
656/**
657 * fixup_leb - fixup/unmap an LEB containing free space.
658 * @c: UBIFS file-system description object
659 * @lnum: the LEB number to fix up
660 * @len: number of used bytes in LEB (starting at offset 0)
661 *
662 * This function reads the contents of the given LEB number @lnum, then fixes
663 * it up, so that empty min. I/O units in the end of LEB are actually erased on
664 * flash (rather than being just all-0xff real data). If the LEB is completely
665 * empty, it is simply unmapped.
666 */
667static int fixup_leb(struct ubifs_info *c, int lnum, int len)
668{
669 int err;
670
671 ubifs_assert(len >= 0);
672 ubifs_assert(len % c->min_io_size == 0);
673 ubifs_assert(len < c->leb_size);
674
675 if (len == 0) {
676 dbg_mnt("unmap empty LEB %d", lnum);
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300677 return ubifs_leb_unmap(c, lnum);
Matthew L. Creech6554a652011-05-06 18:58:22 -0400678 }
679
680 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
Artem Bityutskiyd3048202011-06-03 14:03:25 +0300681 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
Matthew L. Creech6554a652011-05-06 18:58:22 -0400682 if (err)
683 return err;
684
Richard Weinbergerb36a2612012-05-14 17:55:51 +0200685 return ubifs_leb_change(c, lnum, c->sbuf, len);
Matthew L. Creech6554a652011-05-06 18:58:22 -0400686}
687
688/**
689 * fixup_free_space - find & remap all LEBs containing free space.
690 * @c: UBIFS file-system description object
691 *
692 * This function walks through all LEBs in the filesystem and fiexes up those
693 * containing free/empty space.
694 */
695static int fixup_free_space(struct ubifs_info *c)
696{
697 int lnum, err = 0;
698 struct ubifs_lprops *lprops;
699
700 ubifs_get_lprops(c);
701
702 /* Fixup LEBs in the master area */
703 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
704 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
705 if (err)
706 goto out;
707 }
708
709 /* Unmap unused log LEBs */
710 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
711 while (lnum != c->ltail_lnum) {
712 err = fixup_leb(c, lnum, 0);
713 if (err)
714 goto out;
715 lnum = ubifs_next_log_lnum(c, lnum);
716 }
717
Artem Bityutskiyc6727932012-07-14 14:33:09 +0300718 /*
719 * Fixup the log head which contains the only a CS node at the
720 * beginning.
721 */
722 err = fixup_leb(c, c->lhead_lnum,
723 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
Matthew L. Creech6554a652011-05-06 18:58:22 -0400724 if (err)
725 goto out;
726
727 /* Fixup LEBs in the LPT area */
728 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
729 int free = c->ltab[lnum - c->lpt_first].free;
730
731 if (free > 0) {
732 err = fixup_leb(c, lnum, c->leb_size - free);
733 if (err)
734 goto out;
735 }
736 }
737
738 /* Unmap LEBs in the orphans area */
739 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
740 err = fixup_leb(c, lnum, 0);
741 if (err)
742 goto out;
743 }
744
745 /* Fixup LEBs in the main area */
746 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
747 lprops = ubifs_lpt_lookup(c, lnum);
748 if (IS_ERR(lprops)) {
749 err = PTR_ERR(lprops);
750 goto out;
751 }
752
753 if (lprops->free > 0) {
754 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
755 if (err)
756 goto out;
757 }
758 }
759
760out:
761 ubifs_release_lprops(c);
762 return err;
763}
764
765/**
766 * ubifs_fixup_free_space - find & fix all LEBs with free space.
767 * @c: UBIFS file-system description object
768 *
769 * This function fixes up LEBs containing free space on first mount, if the
770 * appropriate flag was set when the FS was created. Each LEB with one or more
771 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
772 * the free space is actually erased. E.g., this is necessary for some NAND
773 * chips, since the free space may have been programmed like real "0xff" data
774 * (generating a non-0xff ECC), causing future writes to the not-really-erased
775 * NAND pages to behave badly. After the space is fixed up, the superblock flag
776 * is cleared, so that this is skipped for all future mounts.
777 */
778int ubifs_fixup_free_space(struct ubifs_info *c)
779{
780 int err;
781 struct ubifs_sb_node *sup;
782
783 ubifs_assert(c->space_fixup);
784 ubifs_assert(!c->ro_mount);
785
786 ubifs_msg("start fixing up free space");
787
788 err = fixup_free_space(c);
789 if (err)
790 return err;
791
792 sup = ubifs_read_sb_node(c);
793 if (IS_ERR(sup))
794 return PTR_ERR(sup);
795
796 /* Free-space fixup is no longer required */
797 c->space_fixup = 0;
798 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
799
800 err = ubifs_write_sb_node(c, sup);
801 kfree(sup);
802 if (err)
803 return err;
804
805 ubifs_msg("free space fixup complete");
806 return err;
807}