blob: 771f7fb6ce92a32b038bd63e1e1fca540493ab60 [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;
133#ifdef CONFIG_UBIFS_FS_DEBUG
134 if (c->leb_cnt - min_leb_cnt > 1)
135 /*
136 * For debugging purposes it is better to have at least 2
137 * orphan LEBs, because the orphan subsystem would need to do
138 * consolidations and would be stressed more.
139 */
140 orph_lebs += 1;
141#endif
142
143 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
144 main_lebs -= orph_lebs;
145
146 lpt_first = UBIFS_LOG_LNUM + log_lebs;
147 c->lsave_cnt = DEFAULT_LSAVE_CNT;
148 c->max_leb_cnt = c->leb_cnt;
149 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
150 &big_lpt);
151 if (err)
152 return err;
153
154 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
155 lpt_first + lpt_lebs - 1);
156
157 main_first = c->leb_cnt - main_lebs;
158
159 /* Create default superblock */
160 tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
161 sup = kzalloc(tmp, GFP_KERNEL);
162 if (!sup)
163 return -ENOMEM;
164
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200165 tmp64 = (long long)max_buds * c->leb_size;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300166 if (big_lpt)
167 sup_flags |= UBIFS_FLG_BIGLPT;
168
169 sup->ch.node_type = UBIFS_SB_NODE;
170 sup->key_hash = UBIFS_KEY_HASH_R5;
171 sup->flags = cpu_to_le32(sup_flags);
172 sup->min_io_size = cpu_to_le32(c->min_io_size);
173 sup->leb_size = cpu_to_le32(c->leb_size);
174 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
175 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
176 sup->max_bud_bytes = cpu_to_le64(tmp64);
177 sup->log_lebs = cpu_to_le32(log_lebs);
178 sup->lpt_lebs = cpu_to_le32(lpt_lebs);
179 sup->orph_lebs = cpu_to_le32(orph_lebs);
180 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
181 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
182 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
183 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300184 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
Artem Bityutskiy553dea42008-11-01 14:57:49 +0200185 if (c->mount_opts.override_compr)
186 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
187 else
188 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300189
190 generate_random_uuid(sup->uuid);
191
Artem Bityutskiy4d61db42008-12-18 14:06:51 +0200192 main_bytes = (long long)main_lebs * c->leb_size;
193 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300194 if (tmp64 > DEFAULT_MAX_RP_SIZE)
195 tmp64 = DEFAULT_MAX_RP_SIZE;
196 sup->rp_size = cpu_to_le64(tmp64);
Artem Bityutskiy963f0cf2009-03-26 12:51:21 +0200197 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300198
199 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM);
200 kfree(sup);
201 if (err)
202 return err;
203
204 dbg_gen("default superblock created at LEB 0:0");
205
206 /* Create default master node */
207 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
208 if (!mst)
209 return -ENOMEM;
210
211 mst->ch.node_type = UBIFS_MST_NODE;
212 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
213 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
214 mst->cmt_no = 0;
215 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
216 mst->root_offs = 0;
217 tmp = ubifs_idx_node_sz(c, 1);
218 mst->root_len = cpu_to_le32(tmp);
219 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
220 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
221 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
222 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
223 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
224 mst->lpt_offs = cpu_to_le32(c->lpt_offs);
225 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
226 mst->nhead_offs = cpu_to_le32(c->nhead_offs);
227 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
228 mst->ltab_offs = cpu_to_le32(c->ltab_offs);
229 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
230 mst->lsave_offs = cpu_to_le32(c->lsave_offs);
231 mst->lscan_lnum = cpu_to_le32(main_first);
232 mst->empty_lebs = cpu_to_le32(main_lebs - 2);
233 mst->idx_lebs = cpu_to_le32(1);
234 mst->leb_cnt = cpu_to_le32(c->leb_cnt);
235
236 /* Calculate lprops statistics */
237 tmp64 = main_bytes;
238 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
239 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
240 mst->total_free = cpu_to_le64(tmp64);
241
242 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
243 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
244 UBIFS_INO_NODE_SZ;
245 tmp64 += ino_waste;
246 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
247 mst->total_dirty = cpu_to_le64(tmp64);
248
249 /* The indexing LEB does not contribute to dark space */
srimugunthan dhandapani7606f852011-08-26 16:08:39 +0530250 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300251 mst->total_dark = cpu_to_le64(tmp64);
252
253 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
254
255 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
256 UBI_UNKNOWN);
257 if (err) {
258 kfree(mst);
259 return err;
260 }
261 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0,
262 UBI_UNKNOWN);
263 kfree(mst);
264 if (err)
265 return err;
266
267 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
268
269 /* Create the root indexing node */
270 tmp = ubifs_idx_node_sz(c, 1);
271 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
272 if (!idx)
273 return -ENOMEM;
274
275 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
276 c->key_hash = key_r5_hash;
277
278 idx->ch.node_type = UBIFS_IDX_NODE;
279 idx->child_cnt = cpu_to_le16(1);
280 ino_key_init(c, &key, UBIFS_ROOT_INO);
281 br = ubifs_idx_branch(c, idx, 0);
282 key_write_idx(c, &key, &br->key);
283 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
284 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
285 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0,
286 UBI_UNKNOWN);
287 kfree(idx);
288 if (err)
289 return err;
290
291 dbg_gen("default root indexing node created LEB %d:0",
292 main_first + DEFAULT_IDX_LEB);
293
294 /* Create default root inode */
295 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
296 ino = kzalloc(tmp, GFP_KERNEL);
297 if (!ino)
298 return -ENOMEM;
299
300 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
301 ino->ch.node_type = UBIFS_INO_NODE;
302 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
303 ino->nlink = cpu_to_le32(2);
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700304 tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
305 ino->atime_sec = tmp_le64;
306 ino->ctime_sec = tmp_le64;
307 ino->mtime_sec = tmp_le64;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300308 ino->atime_nsec = 0;
309 ino->ctime_nsec = 0;
310 ino->mtime_nsec = 0;
311 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
312 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
313
314 /* Set compression enabled by default */
315 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
316
317 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
318 main_first + DEFAULT_DATA_LEB, 0,
319 UBI_UNKNOWN);
320 kfree(ino);
321 if (err)
322 return err;
323
324 dbg_gen("root inode created at LEB %d:0",
325 main_first + DEFAULT_DATA_LEB);
326
327 /*
328 * The first node in the log has to be the commit start node. This is
329 * always the case during normal file-system operation. Write a fake
330 * commit start node to the log.
331 */
332 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
333 cs = kzalloc(tmp, GFP_KERNEL);
334 if (!cs)
335 return -ENOMEM;
336
337 cs->ch.node_type = UBIFS_CS_NODE;
338 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM,
339 0, UBI_UNKNOWN);
340 kfree(cs);
341
342 ubifs_msg("default file-system created");
343 return 0;
344}
345
346/**
347 * validate_sb - validate superblock node.
348 * @c: UBIFS file-system description object
349 * @sup: superblock node
350 *
351 * This function validates superblock node @sup. Since most of data was read
352 * from the superblock and stored in @c, the function validates fields in @c
353 * instead. Returns zero in case of success and %-EINVAL in case of validation
354 * failure.
355 */
356static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
357{
358 long long max_bytes;
359 int err = 1, min_leb_cnt;
360
361 if (!c->key_hash) {
362 err = 2;
363 goto failed;
364 }
365
366 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
367 err = 3;
368 goto failed;
369 }
370
371 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
372 ubifs_err("min. I/O unit mismatch: %d in superblock, %d real",
373 le32_to_cpu(sup->min_io_size), c->min_io_size);
374 goto failed;
375 }
376
377 if (le32_to_cpu(sup->leb_size) != c->leb_size) {
378 ubifs_err("LEB size mismatch: %d in superblock, %d real",
379 le32_to_cpu(sup->leb_size), c->leb_size);
380 goto failed;
381 }
382
383 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
384 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
385 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
386 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
387 err = 4;
388 goto failed;
389 }
390
391 /*
392 * Calculate minimum allowed amount of main area LEBs. This is very
393 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
394 * have just read from the superblock.
395 */
396 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
397 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
398
399 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
400 ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, "
401 "%d minimum required", c->leb_cnt, c->vi.size,
402 min_leb_cnt);
403 goto failed;
404 }
405
406 if (c->max_leb_cnt < c->leb_cnt) {
407 ubifs_err("max. LEB count %d less than LEB count %d",
408 c->max_leb_cnt, c->leb_cnt);
409 goto failed;
410 }
411
412 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
Artem Bityutskiy5a1f36c2012-03-07 16:29:45 +0200413 ubifs_err("too few main LEBs count %d, must be at least %d",
414 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300415 goto failed;
416 }
417
Artem Bityutskiy5a1f36c2012-03-07 16:29:45 +0200418 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
419 if (c->max_bud_bytes < max_bytes) {
420 ubifs_err("too small journal (%lld bytes), must be at least "
421 "%lld bytes", c->max_bud_bytes, max_bytes);
422 goto failed;
423 }
424
425 max_bytes = (long long)c->leb_size * c->main_lebs;
426 if (c->max_bud_bytes > max_bytes) {
427 ubifs_err("too large journal size (%lld bytes), only %lld bytes"
428 "available in the main area",
429 c->max_bud_bytes, max_bytes);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300430 goto failed;
431 }
432
433 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
434 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
435 err = 9;
436 goto failed;
437 }
438
439 if (c->fanout < UBIFS_MIN_FANOUT ||
440 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
441 err = 10;
442 goto failed;
443 }
444
445 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
446 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
447 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
448 err = 11;
449 goto failed;
450 }
451
452 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
453 c->orph_lebs + c->main_lebs != c->leb_cnt) {
454 err = 12;
455 goto failed;
456 }
457
458 if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
459 err = 13;
460 goto failed;
461 }
462
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300463 if (c->rp_size < 0 || max_bytes < c->rp_size) {
464 err = 14;
465 goto failed;
466 }
467
468 if (le32_to_cpu(sup->time_gran) > 1000000000 ||
469 le32_to_cpu(sup->time_gran) < 1) {
470 err = 15;
471 goto failed;
472 }
473
474 return 0;
475
476failed:
477 ubifs_err("bad superblock, error %d", err);
478 dbg_dump_node(c, sup);
479 return -EINVAL;
480}
481
482/**
483 * ubifs_read_sb_node - read superblock node.
484 * @c: UBIFS file-system description object
485 *
486 * This function returns a pointer to the superblock node or a negative error
Artem Bityutskiyeaeee242011-05-06 17:08:56 +0300487 * code. Note, the user of this function is responsible of kfree()'ing the
488 * returned superblock buffer.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300489 */
490struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
491{
492 struct ubifs_sb_node *sup;
493 int err;
494
495 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
496 if (!sup)
497 return ERR_PTR(-ENOMEM);
498
499 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
500 UBIFS_SB_LNUM, 0);
501 if (err) {
502 kfree(sup);
503 return ERR_PTR(err);
504 }
505
506 return sup;
507}
508
509/**
510 * ubifs_write_sb_node - write superblock node.
511 * @c: UBIFS file-system description object
512 * @sup: superblock node read with 'ubifs_read_sb_node()'
513 *
514 * This function returns %0 on success and a negative error code on failure.
515 */
516int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
517{
518 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
519
520 ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
521 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM);
522}
523
524/**
525 * ubifs_read_superblock - read superblock.
526 * @c: UBIFS file-system description object
527 *
528 * This function finds, reads and checks the superblock. If an empty UBI volume
529 * is being mounted, this function creates default superblock. Returns zero in
530 * case of success, and a negative error code in case of failure.
531 */
532int ubifs_read_superblock(struct ubifs_info *c)
533{
534 int err, sup_flags;
535 struct ubifs_sb_node *sup;
536
537 if (c->empty) {
538 err = create_default_filesystem(c);
539 if (err)
540 return err;
541 }
542
543 sup = ubifs_read_sb_node(c);
544 if (IS_ERR(sup))
545 return PTR_ERR(sup);
546
Artem Bityutskiy963f0cf2009-03-26 12:51:21 +0200547 c->fmt_version = le32_to_cpu(sup->fmt_version);
548 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
549
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300550 /*
551 * The software supports all previous versions but not future versions,
552 * due to the unavailability of time-travelling equipment.
553 */
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300554 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300555 ubifs_assert(!c->ro_media || c->ro_mount);
556 if (!c->ro_mount ||
Artem Bityutskiy963f0cf2009-03-26 12:51:21 +0200557 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
558 ubifs_err("on-flash format version is w%d/r%d, but "
559 "software only supports up to version "
560 "w%d/r%d", c->fmt_version,
561 c->ro_compat_version, UBIFS_FORMAT_VERSION,
562 UBIFS_RO_COMPAT_VERSION);
563 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
564 ubifs_msg("only R/O mounting is possible");
565 err = -EROFS;
566 } else
567 err = -EINVAL;
568 goto out;
569 }
570
571 /*
572 * The FS is mounted R/O, and the media format is
573 * R/O-compatible with the UBIFS implementation, so we can
574 * mount.
575 */
576 c->rw_incompat = 1;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300577 }
578
579 if (c->fmt_version < 3) {
580 ubifs_err("on-flash format version %d is not supported",
581 c->fmt_version);
582 err = -EINVAL;
583 goto out;
584 }
585
586 switch (sup->key_hash) {
587 case UBIFS_KEY_HASH_R5:
588 c->key_hash = key_r5_hash;
589 c->key_hash_type = UBIFS_KEY_HASH_R5;
590 break;
591
592 case UBIFS_KEY_HASH_TEST:
593 c->key_hash = key_test_hash;
594 c->key_hash_type = UBIFS_KEY_HASH_TEST;
595 break;
596 };
597
598 c->key_fmt = sup->key_fmt;
599
600 switch (c->key_fmt) {
601 case UBIFS_SIMPLE_KEY_FMT:
602 c->key_len = UBIFS_SK_LEN;
603 break;
604 default:
605 ubifs_err("unsupported key format");
606 err = -EINVAL;
607 goto out;
608 }
609
610 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
611 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
612 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
613 c->log_lebs = le32_to_cpu(sup->log_lebs);
614 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
615 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
616 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
617 c->fanout = le32_to_cpu(sup->fanout);
618 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300619 c->rp_size = le64_to_cpu(sup->rp_size);
620 c->rp_uid = le32_to_cpu(sup->rp_uid);
621 c->rp_gid = le32_to_cpu(sup->rp_gid);
622 sup_flags = le32_to_cpu(sup->flags);
Artem Bityutskiy553dea42008-11-01 14:57:49 +0200623 if (!c->mount_opts.override_compr)
624 c->default_compr = le16_to_cpu(sup->default_compr);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300625
626 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300627 memcpy(&c->uuid, &sup->uuid, 16);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300628 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
Matthew L. Creech9f58d352011-05-05 16:33:20 -0400629 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300630
631 /* Automatically increase file system size to the maximum size */
632 c->old_leb_cnt = c->leb_cnt;
633 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
634 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
Artem Bityutskiy2ef13292010-09-19 18:34:26 +0300635 if (c->ro_mount)
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300636 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
637 c->old_leb_cnt, c->leb_cnt);
638 else {
639 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
640 c->old_leb_cnt, c->leb_cnt);
641 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
642 err = ubifs_write_sb_node(c, sup);
643 if (err)
644 goto out;
645 c->old_leb_cnt = c->leb_cnt;
646 }
647 }
648
649 c->log_bytes = (long long)c->log_lebs * c->leb_size;
650 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
651 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
652 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
653 c->orph_first = c->lpt_last + 1;
654 c->orph_last = c->orph_first + c->orph_lebs - 1;
655 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
656 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
657 c->main_first = c->leb_cnt - c->main_lebs;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300658
659 err = validate_sb(c, sup);
660out:
661 kfree(sup);
662 return err;
663}
Matthew L. Creech6554a652011-05-06 18:58:22 -0400664
665/**
666 * fixup_leb - fixup/unmap an LEB containing free space.
667 * @c: UBIFS file-system description object
668 * @lnum: the LEB number to fix up
669 * @len: number of used bytes in LEB (starting at offset 0)
670 *
671 * This function reads the contents of the given LEB number @lnum, then fixes
672 * it up, so that empty min. I/O units in the end of LEB are actually erased on
673 * flash (rather than being just all-0xff real data). If the LEB is completely
674 * empty, it is simply unmapped.
675 */
676static int fixup_leb(struct ubifs_info *c, int lnum, int len)
677{
678 int err;
679
680 ubifs_assert(len >= 0);
681 ubifs_assert(len % c->min_io_size == 0);
682 ubifs_assert(len < c->leb_size);
683
684 if (len == 0) {
685 dbg_mnt("unmap empty LEB %d", lnum);
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300686 return ubifs_leb_unmap(c, lnum);
Matthew L. Creech6554a652011-05-06 18:58:22 -0400687 }
688
689 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
Artem Bityutskiyd3048202011-06-03 14:03:25 +0300690 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
Matthew L. Creech6554a652011-05-06 18:58:22 -0400691 if (err)
692 return err;
693
Artem Bityutskiyd3b25782011-06-03 14:22:05 +0300694 return ubifs_leb_change(c, lnum, c->sbuf, len, UBI_UNKNOWN);
Matthew L. Creech6554a652011-05-06 18:58:22 -0400695}
696
697/**
698 * fixup_free_space - find & remap all LEBs containing free space.
699 * @c: UBIFS file-system description object
700 *
701 * This function walks through all LEBs in the filesystem and fiexes up those
702 * containing free/empty space.
703 */
704static int fixup_free_space(struct ubifs_info *c)
705{
706 int lnum, err = 0;
707 struct ubifs_lprops *lprops;
708
709 ubifs_get_lprops(c);
710
711 /* Fixup LEBs in the master area */
712 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
713 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
714 if (err)
715 goto out;
716 }
717
718 /* Unmap unused log LEBs */
719 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
720 while (lnum != c->ltail_lnum) {
721 err = fixup_leb(c, lnum, 0);
722 if (err)
723 goto out;
724 lnum = ubifs_next_log_lnum(c, lnum);
725 }
726
727 /* Fixup the current log head */
728 err = fixup_leb(c, c->lhead_lnum, c->lhead_offs);
729 if (err)
730 goto out;
731
732 /* Fixup LEBs in the LPT area */
733 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
734 int free = c->ltab[lnum - c->lpt_first].free;
735
736 if (free > 0) {
737 err = fixup_leb(c, lnum, c->leb_size - free);
738 if (err)
739 goto out;
740 }
741 }
742
743 /* Unmap LEBs in the orphans area */
744 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
745 err = fixup_leb(c, lnum, 0);
746 if (err)
747 goto out;
748 }
749
750 /* Fixup LEBs in the main area */
751 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
752 lprops = ubifs_lpt_lookup(c, lnum);
753 if (IS_ERR(lprops)) {
754 err = PTR_ERR(lprops);
755 goto out;
756 }
757
758 if (lprops->free > 0) {
759 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
760 if (err)
761 goto out;
762 }
763 }
764
765out:
766 ubifs_release_lprops(c);
767 return err;
768}
769
770/**
771 * ubifs_fixup_free_space - find & fix all LEBs with free space.
772 * @c: UBIFS file-system description object
773 *
774 * This function fixes up LEBs containing free space on first mount, if the
775 * appropriate flag was set when the FS was created. Each LEB with one or more
776 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
777 * the free space is actually erased. E.g., this is necessary for some NAND
778 * chips, since the free space may have been programmed like real "0xff" data
779 * (generating a non-0xff ECC), causing future writes to the not-really-erased
780 * NAND pages to behave badly. After the space is fixed up, the superblock flag
781 * is cleared, so that this is skipped for all future mounts.
782 */
783int ubifs_fixup_free_space(struct ubifs_info *c)
784{
785 int err;
786 struct ubifs_sb_node *sup;
787
788 ubifs_assert(c->space_fixup);
789 ubifs_assert(!c->ro_mount);
790
791 ubifs_msg("start fixing up free space");
792
793 err = fixup_free_space(c);
794 if (err)
795 return err;
796
797 sup = ubifs_read_sb_node(c);
798 if (IS_ERR(sup))
799 return PTR_ERR(sup);
800
801 /* Free-space fixup is no longer required */
802 c->space_fixup = 0;
803 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
804
805 err = ubifs_write_sb_node(c, sup);
806 kfree(sup);
807 if (err)
808 return err;
809
810 ubifs_msg("free space fixup complete");
811 return err;
812}