blob: 7c7d92a6031ef93088432817cd292dff121204a2 [file] [log] [blame]
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
Heiko Schocherff94bc42014-06-24 10:10:04 +02006 * SPDX-License-Identifier: GPL-2.0+
Stefan Roese9eefe2a2009-03-19 15:35:05 +01007 *
8 * Authors: Artem Bityutskiy (Битюцкий Артём)
9 * Adrian Hunter
10 */
11
12/*
13 * This file implements UBIFS superblock. The superblock is stored at the first
14 * LEB of the volume and is never changed by UBIFS. Only user-space tools may
15 * change it. The superblock node mostly contains geometry information.
16 */
17
18#include "ubifs.h"
Heiko Schocherff94bc42014-06-24 10:10:04 +020019#ifndef __UBOOT__
20#include <linux/slab.h>
21#include <linux/random.h>
22#include <linux/math64.h>
23#else
24
25#include <linux/compat.h>
26#include <linux/err.h>
27#include <ubi_uboot.h>
28#include <linux/stat.h>
29#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +010030
31/*
32 * Default journal size in logical eraseblocks as a percent of total
33 * flash size.
34 */
35#define DEFAULT_JNL_PERCENT 5
36
37/* Default maximum journal size in bytes */
38#define DEFAULT_MAX_JNL (32*1024*1024)
39
40/* Default indexing tree fanout */
41#define DEFAULT_FANOUT 8
42
43/* Default number of data journal heads */
44#define DEFAULT_JHEADS_CNT 1
45
46/* Default positions of different LEBs in the main area */
47#define DEFAULT_IDX_LEB 0
48#define DEFAULT_DATA_LEB 1
49#define DEFAULT_GC_LEB 2
50
51/* Default number of LEB numbers in LPT's save table */
52#define DEFAULT_LSAVE_CNT 256
53
54/* Default reserved pool size as a percent of maximum free space */
55#define DEFAULT_RP_PERCENT 5
56
57/* The default maximum size of reserved pool in bytes */
58#define DEFAULT_MAX_RP_SIZE (5*1024*1024)
59
60/* Default time granularity in nanoseconds */
61#define DEFAULT_TIME_GRAN 1000000000
62
Heiko Schocherff94bc42014-06-24 10:10:04 +020063#ifndef __UBOOT__
64/**
65 * create_default_filesystem - format empty UBI volume.
66 * @c: UBIFS file-system description object
67 *
68 * This function creates default empty file-system. Returns zero in case of
69 * success and a negative error code in case of failure.
70 */
71static int create_default_filesystem(struct ubifs_info *c)
72{
73 struct ubifs_sb_node *sup;
74 struct ubifs_mst_node *mst;
75 struct ubifs_idx_node *idx;
76 struct ubifs_branch *br;
77 struct ubifs_ino_node *ino;
78 struct ubifs_cs_node *cs;
79 union ubifs_key key;
80 int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;
81 int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
82 int min_leb_cnt = UBIFS_MIN_LEB_CNT;
83 long long tmp64, main_bytes;
84 __le64 tmp_le64;
85
86 /* Some functions called from here depend on the @c->key_len filed */
87 c->key_len = UBIFS_SK_LEN;
88
89 /*
90 * First of all, we have to calculate default file-system geometry -
91 * log size, journal size, etc.
92 */
93 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
94 /* We can first multiply then divide and have no overflow */
95 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
96 else
97 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
98
99 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
100 jnl_lebs = UBIFS_MIN_JNL_LEBS;
101 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
102 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
103
104 /*
105 * The log should be large enough to fit reference nodes for all bud
106 * LEBs. Because buds do not have to start from the beginning of LEBs
107 * (half of the LEB may contain committed data), the log should
108 * generally be larger, make it twice as large.
109 */
110 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
111 log_lebs = tmp / c->leb_size;
112 /* Plus one LEB reserved for commit */
113 log_lebs += 1;
114 if (c->leb_cnt - min_leb_cnt > 8) {
115 /* And some extra space to allow writes while committing */
116 log_lebs += 1;
117 min_leb_cnt += 1;
118 }
119
120 max_buds = jnl_lebs - log_lebs;
121 if (max_buds < UBIFS_MIN_BUD_LEBS)
122 max_buds = UBIFS_MIN_BUD_LEBS;
123
124 /*
125 * Orphan nodes are stored in a separate area. One node can store a lot
126 * of orphan inode numbers, but when new orphan comes we just add a new
127 * orphan node. At some point the nodes are consolidated into one
128 * orphan node.
129 */
130 orph_lebs = UBIFS_MIN_ORPH_LEBS;
131 if (c->leb_cnt - min_leb_cnt > 1)
132 /*
133 * For debugging purposes it is better to have at least 2
134 * orphan LEBs, because the orphan subsystem would need to do
135 * consolidations and would be stressed more.
136 */
137 orph_lebs += 1;
138
139 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
140 main_lebs -= orph_lebs;
141
142 lpt_first = UBIFS_LOG_LNUM + log_lebs;
143 c->lsave_cnt = DEFAULT_LSAVE_CNT;
144 c->max_leb_cnt = c->leb_cnt;
145 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
146 &big_lpt);
147 if (err)
148 return err;
149
150 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
151 lpt_first + lpt_lebs - 1);
152
153 main_first = c->leb_cnt - main_lebs;
154
155 /* Create default superblock */
156 tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
157 sup = kzalloc(tmp, GFP_KERNEL);
158 if (!sup)
159 return -ENOMEM;
160
161 tmp64 = (long long)max_buds * c->leb_size;
162 if (big_lpt)
163 sup_flags |= UBIFS_FLG_BIGLPT;
164
165 sup->ch.node_type = UBIFS_SB_NODE;
166 sup->key_hash = UBIFS_KEY_HASH_R5;
167 sup->flags = cpu_to_le32(sup_flags);
168 sup->min_io_size = cpu_to_le32(c->min_io_size);
169 sup->leb_size = cpu_to_le32(c->leb_size);
170 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
171 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
172 sup->max_bud_bytes = cpu_to_le64(tmp64);
173 sup->log_lebs = cpu_to_le32(log_lebs);
174 sup->lpt_lebs = cpu_to_le32(lpt_lebs);
175 sup->orph_lebs = cpu_to_le32(orph_lebs);
176 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
177 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
178 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
179 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
180 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
181 if (c->mount_opts.override_compr)
182 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
183 else
184 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
185
186 generate_random_uuid(sup->uuid);
187
188 main_bytes = (long long)main_lebs * c->leb_size;
189 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
190 if (tmp64 > DEFAULT_MAX_RP_SIZE)
191 tmp64 = DEFAULT_MAX_RP_SIZE;
192 sup->rp_size = cpu_to_le64(tmp64);
193 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
194
195 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0);
196 kfree(sup);
197 if (err)
198 return err;
199
200 dbg_gen("default superblock created at LEB 0:0");
201
202 /* Create default master node */
203 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
204 if (!mst)
205 return -ENOMEM;
206
207 mst->ch.node_type = UBIFS_MST_NODE;
208 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
209 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
210 mst->cmt_no = 0;
211 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
212 mst->root_offs = 0;
213 tmp = ubifs_idx_node_sz(c, 1);
214 mst->root_len = cpu_to_le32(tmp);
215 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
216 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
217 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
218 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
219 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
220 mst->lpt_offs = cpu_to_le32(c->lpt_offs);
221 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
222 mst->nhead_offs = cpu_to_le32(c->nhead_offs);
223 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
224 mst->ltab_offs = cpu_to_le32(c->ltab_offs);
225 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
226 mst->lsave_offs = cpu_to_le32(c->lsave_offs);
227 mst->lscan_lnum = cpu_to_le32(main_first);
228 mst->empty_lebs = cpu_to_le32(main_lebs - 2);
229 mst->idx_lebs = cpu_to_le32(1);
230 mst->leb_cnt = cpu_to_le32(c->leb_cnt);
231
232 /* Calculate lprops statistics */
233 tmp64 = main_bytes;
234 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
235 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
236 mst->total_free = cpu_to_le64(tmp64);
237
238 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
239 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
240 UBIFS_INO_NODE_SZ;
241 tmp64 += ino_waste;
242 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
243 mst->total_dirty = cpu_to_le64(tmp64);
244
245 /* The indexing LEB does not contribute to dark space */
246 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
247 mst->total_dark = cpu_to_le64(tmp64);
248
249 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
250
251 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0);
252 if (err) {
253 kfree(mst);
254 return err;
255 }
256 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
257 0);
258 kfree(mst);
259 if (err)
260 return err;
261
262 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
263
264 /* Create the root indexing node */
265 tmp = ubifs_idx_node_sz(c, 1);
266 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
267 if (!idx)
268 return -ENOMEM;
269
270 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
271 c->key_hash = key_r5_hash;
272
273 idx->ch.node_type = UBIFS_IDX_NODE;
274 idx->child_cnt = cpu_to_le16(1);
275 ino_key_init(c, &key, UBIFS_ROOT_INO);
276 br = ubifs_idx_branch(c, idx, 0);
277 key_write_idx(c, &key, &br->key);
278 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
279 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
280 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0);
281 kfree(idx);
282 if (err)
283 return err;
284
285 dbg_gen("default root indexing node created LEB %d:0",
286 main_first + DEFAULT_IDX_LEB);
287
288 /* Create default root inode */
289 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
290 ino = kzalloc(tmp, GFP_KERNEL);
291 if (!ino)
292 return -ENOMEM;
293
294 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
295 ino->ch.node_type = UBIFS_INO_NODE;
296 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
297 ino->nlink = cpu_to_le32(2);
298 tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
299 ino->atime_sec = tmp_le64;
300 ino->ctime_sec = tmp_le64;
301 ino->mtime_sec = tmp_le64;
302 ino->atime_nsec = 0;
303 ino->ctime_nsec = 0;
304 ino->mtime_nsec = 0;
305 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
306 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
307
308 /* Set compression enabled by default */
309 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
310
311 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
312 main_first + DEFAULT_DATA_LEB, 0);
313 kfree(ino);
314 if (err)
315 return err;
316
317 dbg_gen("root inode created at LEB %d:0",
318 main_first + DEFAULT_DATA_LEB);
319
320 /*
321 * The first node in the log has to be the commit start node. This is
322 * always the case during normal file-system operation. Write a fake
323 * commit start node to the log.
324 */
325 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
326 cs = kzalloc(tmp, GFP_KERNEL);
327 if (!cs)
328 return -ENOMEM;
329
330 cs->ch.node_type = UBIFS_CS_NODE;
331 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
332 kfree(cs);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200333 if (err)
334 return err;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200335
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200336 ubifs_msg(c, "default file-system created");
Heiko Schocherff94bc42014-06-24 10:10:04 +0200337 return 0;
338}
339#endif
340
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100341/**
342 * validate_sb - validate superblock node.
343 * @c: UBIFS file-system description object
344 * @sup: superblock node
345 *
346 * This function validates superblock node @sup. Since most of data was read
347 * from the superblock and stored in @c, the function validates fields in @c
348 * instead. Returns zero in case of success and %-EINVAL in case of validation
349 * failure.
350 */
351static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
352{
353 long long max_bytes;
354 int err = 1, min_leb_cnt;
355
356 if (!c->key_hash) {
357 err = 2;
358 goto failed;
359 }
360
361 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
362 err = 3;
363 goto failed;
364 }
365
366 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200367 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100368 le32_to_cpu(sup->min_io_size), c->min_io_size);
369 goto failed;
370 }
371
372 if (le32_to_cpu(sup->leb_size) != c->leb_size) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200373 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100374 le32_to_cpu(sup->leb_size), c->leb_size);
375 goto failed;
376 }
377
378 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
379 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
380 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
381 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
382 err = 4;
383 goto failed;
384 }
385
386 /*
387 * Calculate minimum allowed amount of main area LEBs. This is very
388 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
389 * have just read from the superblock.
390 */
391 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
392 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
393
394 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200395 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200396 c->leb_cnt, c->vi.size, min_leb_cnt);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100397 goto failed;
398 }
399
400 if (c->max_leb_cnt < c->leb_cnt) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200401 ubifs_err(c, "max. LEB count %d less than LEB count %d",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100402 c->max_leb_cnt, c->leb_cnt);
403 goto failed;
404 }
405
406 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200407 ubifs_err(c, "too few main LEBs count %d, must be at least %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200408 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100409 goto failed;
410 }
411
Heiko Schocherff94bc42014-06-24 10:10:04 +0200412 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
413 if (c->max_bud_bytes < max_bytes) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200414 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200415 c->max_bud_bytes, max_bytes);
416 goto failed;
417 }
418
419 max_bytes = (long long)c->leb_size * c->main_lebs;
420 if (c->max_bud_bytes > max_bytes) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200421 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200422 c->max_bud_bytes, max_bytes);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100423 goto failed;
424 }
425
426 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
427 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
428 err = 9;
429 goto failed;
430 }
431
432 if (c->fanout < UBIFS_MIN_FANOUT ||
433 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
434 err = 10;
435 goto failed;
436 }
437
438 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
439 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
440 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
441 err = 11;
442 goto failed;
443 }
444
445 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
446 c->orph_lebs + c->main_lebs != c->leb_cnt) {
447 err = 12;
448 goto failed;
449 }
450
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200451 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100452 err = 13;
453 goto failed;
454 }
455
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100456 if (c->rp_size < 0 || max_bytes < c->rp_size) {
457 err = 14;
458 goto failed;
459 }
460
461 if (le32_to_cpu(sup->time_gran) > 1000000000 ||
462 le32_to_cpu(sup->time_gran) < 1) {
463 err = 15;
464 goto failed;
465 }
466
467 return 0;
468
469failed:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200470 ubifs_err(c, "bad superblock, error %d", err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200471 ubifs_dump_node(c, sup);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100472 return -EINVAL;
473}
474
475/**
476 * ubifs_read_sb_node - read superblock node.
477 * @c: UBIFS file-system description object
478 *
479 * This function returns a pointer to the superblock node or a negative error
Heiko Schocherff94bc42014-06-24 10:10:04 +0200480 * code. Note, the user of this function is responsible of kfree()'ing the
481 * returned superblock buffer.
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100482 */
483struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
484{
485 struct ubifs_sb_node *sup;
486 int err;
487
488 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
489 if (!sup)
490 return ERR_PTR(-ENOMEM);
491
492 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
493 UBIFS_SB_LNUM, 0);
494 if (err) {
495 kfree(sup);
496 return ERR_PTR(err);
497 }
498
499 return sup;
500}
501
502/**
Heiko Schocherff94bc42014-06-24 10:10:04 +0200503 * ubifs_write_sb_node - write superblock node.
504 * @c: UBIFS file-system description object
505 * @sup: superblock node read with 'ubifs_read_sb_node()'
506 *
507 * This function returns %0 on success and a negative error code on failure.
508 */
509int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
510{
511 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
512
513 ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
514 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);
515}
516
517/**
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100518 * ubifs_read_superblock - read superblock.
519 * @c: UBIFS file-system description object
520 *
521 * This function finds, reads and checks the superblock. If an empty UBI volume
522 * is being mounted, this function creates default superblock. Returns zero in
523 * case of success, and a negative error code in case of failure.
524 */
525int ubifs_read_superblock(struct ubifs_info *c)
526{
527 int err, sup_flags;
528 struct ubifs_sb_node *sup;
529
530 if (c->empty) {
Heiko Schocherff94bc42014-06-24 10:10:04 +0200531#ifndef __UBOOT__
532 err = create_default_filesystem(c);
533 if (err)
534 return err;
535#else
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100536 printf("No UBIFS filesystem found!\n");
537 return -1;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200538#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100539 }
540
541 sup = ubifs_read_sb_node(c);
542 if (IS_ERR(sup))
543 return PTR_ERR(sup);
544
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100545 c->fmt_version = le32_to_cpu(sup->fmt_version);
546 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
547
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100548 /*
549 * The software supports all previous versions but not future versions,
550 * due to the unavailability of time-travelling equipment.
551 */
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100552 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
Heiko Schocherff94bc42014-06-24 10:10:04 +0200553 ubifs_assert(!c->ro_media || c->ro_mount);
554 if (!c->ro_mount ||
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100555 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200556 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200557 c->fmt_version, c->ro_compat_version,
558 UBIFS_FORMAT_VERSION,
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100559 UBIFS_RO_COMPAT_VERSION);
560 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200561 ubifs_msg(c, "only R/O mounting is possible");
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100562 err = -EROFS;
563 } else
564 err = -EINVAL;
565 goto out;
566 }
567
568 /*
569 * The FS is mounted R/O, and the media format is
570 * R/O-compatible with the UBIFS implementation, so we can
571 * mount.
572 */
573 c->rw_incompat = 1;
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100574 }
575
576 if (c->fmt_version < 3) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200577 ubifs_err(c, "on-flash format version %d is not supported",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100578 c->fmt_version);
579 err = -EINVAL;
580 goto out;
581 }
582
583 switch (sup->key_hash) {
584 case UBIFS_KEY_HASH_R5:
585 c->key_hash = key_r5_hash;
586 c->key_hash_type = UBIFS_KEY_HASH_R5;
587 break;
588
589 case UBIFS_KEY_HASH_TEST:
590 c->key_hash = key_test_hash;
591 c->key_hash_type = UBIFS_KEY_HASH_TEST;
592 break;
593 };
594
595 c->key_fmt = sup->key_fmt;
596
597 switch (c->key_fmt) {
598 case UBIFS_SIMPLE_KEY_FMT:
599 c->key_len = UBIFS_SK_LEN;
600 break;
601 default:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200602 ubifs_err(c, "unsupported key format");
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100603 err = -EINVAL;
604 goto out;
605 }
606
607 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
608 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
609 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
610 c->log_lebs = le32_to_cpu(sup->log_lebs);
611 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
612 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
613 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
614 c->fanout = le32_to_cpu(sup->fanout);
615 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100616 c->rp_size = le64_to_cpu(sup->rp_size);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200617#ifndef __UBOOT__
618 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
619 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
620#else
621 c->rp_uid.val = le32_to_cpu(sup->rp_uid);
622 c->rp_gid.val = le32_to_cpu(sup->rp_gid);
623#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100624 sup_flags = le32_to_cpu(sup->flags);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200625 if (!c->mount_opts.override_compr)
626 c->default_compr = le16_to_cpu(sup->default_compr);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100627
628 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
629 memcpy(&c->uuid, &sup->uuid, 16);
630 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200631 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100632
633 /* Automatically increase file system size to the maximum size */
634 c->old_leb_cnt = c->leb_cnt;
635 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
636 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200637 if (c->ro_mount)
638 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
639 c->old_leb_cnt, c->leb_cnt);
640#ifndef __UBOOT__
641 else {
642 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
643 c->old_leb_cnt, c->leb_cnt);
644 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
645 err = ubifs_write_sb_node(c, sup);
646 if (err)
647 goto out;
648 c->old_leb_cnt = c->leb_cnt;
649 }
650#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100651 }
652
653 c->log_bytes = (long long)c->log_lebs * c->leb_size;
654 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
655 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
656 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
657 c->orph_first = c->lpt_last + 1;
658 c->orph_last = c->orph_first + c->orph_lebs - 1;
659 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
660 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
661 c->main_first = c->leb_cnt - c->main_lebs;
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100662
663 err = validate_sb(c, sup);
664out:
665 kfree(sup);
666 return err;
667}
Heiko Schocherff94bc42014-06-24 10:10:04 +0200668
669/**
670 * fixup_leb - fixup/unmap an LEB containing free space.
671 * @c: UBIFS file-system description object
672 * @lnum: the LEB number to fix up
673 * @len: number of used bytes in LEB (starting at offset 0)
674 *
675 * This function reads the contents of the given LEB number @lnum, then fixes
676 * it up, so that empty min. I/O units in the end of LEB are actually erased on
677 * flash (rather than being just all-0xff real data). If the LEB is completely
678 * empty, it is simply unmapped.
679 */
680static int fixup_leb(struct ubifs_info *c, int lnum, int len)
681{
682 int err;
683
684 ubifs_assert(len >= 0);
685 ubifs_assert(len % c->min_io_size == 0);
686 ubifs_assert(len < c->leb_size);
687
688 if (len == 0) {
689 dbg_mnt("unmap empty LEB %d", lnum);
690 return ubifs_leb_unmap(c, lnum);
691 }
692
693 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
694 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
695 if (err)
696 return err;
697
698 return ubifs_leb_change(c, lnum, c->sbuf, len);
699}
700
701/**
702 * fixup_free_space - find & remap all LEBs containing free space.
703 * @c: UBIFS file-system description object
704 *
705 * This function walks through all LEBs in the filesystem and fiexes up those
706 * containing free/empty space.
707 */
708static int fixup_free_space(struct ubifs_info *c)
709{
710 int lnum, err = 0;
711 struct ubifs_lprops *lprops;
712
713 ubifs_get_lprops(c);
714
715 /* Fixup LEBs in the master area */
716 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
717 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
718 if (err)
719 goto out;
720 }
721
722 /* Unmap unused log LEBs */
723 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
724 while (lnum != c->ltail_lnum) {
725 err = fixup_leb(c, lnum, 0);
726 if (err)
727 goto out;
728 lnum = ubifs_next_log_lnum(c, lnum);
729 }
730
731 /*
732 * Fixup the log head which contains the only a CS node at the
733 * beginning.
734 */
735 err = fixup_leb(c, c->lhead_lnum,
736 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
737 if (err)
738 goto out;
739
740 /* Fixup LEBs in the LPT area */
741 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
742 int free = c->ltab[lnum - c->lpt_first].free;
743
744 if (free > 0) {
745 err = fixup_leb(c, lnum, c->leb_size - free);
746 if (err)
747 goto out;
748 }
749 }
750
751 /* Unmap LEBs in the orphans area */
752 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
753 err = fixup_leb(c, lnum, 0);
754 if (err)
755 goto out;
756 }
757
758 /* Fixup LEBs in the main area */
759 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
760 lprops = ubifs_lpt_lookup(c, lnum);
761 if (IS_ERR(lprops)) {
762 err = PTR_ERR(lprops);
763 goto out;
764 }
765
766 if (lprops->free > 0) {
767 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
768 if (err)
769 goto out;
770 }
771 }
772
773out:
774 ubifs_release_lprops(c);
775 return err;
776}
777
778/**
779 * ubifs_fixup_free_space - find & fix all LEBs with free space.
780 * @c: UBIFS file-system description object
781 *
782 * This function fixes up LEBs containing free space on first mount, if the
783 * appropriate flag was set when the FS was created. Each LEB with one or more
784 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
785 * the free space is actually erased. E.g., this is necessary for some NAND
786 * chips, since the free space may have been programmed like real "0xff" data
787 * (generating a non-0xff ECC), causing future writes to the not-really-erased
788 * NAND pages to behave badly. After the space is fixed up, the superblock flag
789 * is cleared, so that this is skipped for all future mounts.
790 */
791int ubifs_fixup_free_space(struct ubifs_info *c)
792{
793 int err;
794 struct ubifs_sb_node *sup;
795
796 ubifs_assert(c->space_fixup);
797 ubifs_assert(!c->ro_mount);
798
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200799 ubifs_msg(c, "start fixing up free space");
Heiko Schocherff94bc42014-06-24 10:10:04 +0200800
801 err = fixup_free_space(c);
802 if (err)
803 return err;
804
805 sup = ubifs_read_sb_node(c);
806 if (IS_ERR(sup))
807 return PTR_ERR(sup);
808
809 /* Free-space fixup is no longer required */
810 c->space_fixup = 0;
811 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
812
813 err = ubifs_write_sb_node(c, sup);
814 kfree(sup);
815 if (err)
816 return err;
817
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200818 ubifs_msg(c, "free space fixup complete");
Heiko Schocherff94bc42014-06-24 10:10:04 +0200819 return err;
820}