blob: 52db611d1c7bf60301b8fb743f8672518c4c711a [file] [log] [blame]
Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Stefan Roese9eefe2a2009-03-19 15:35:05 +01002/*
3 * This file is part of UBIFS.
4 *
5 * Copyright (C) 2006-2008 Nokia Corporation.
6 *
Stefan Roese9eefe2a2009-03-19 15:35:05 +01007 * Authors: Artem Bityutskiy (Битюцкий Артём)
8 * Adrian Hunter
9 */
10
11/*
12 * This file implements UBIFS superblock. The superblock is stored at the first
13 * LEB of the volume and is never changed by UBIFS. Only user-space tools may
14 * change it. The superblock node mostly contains geometry information.
15 */
16
17#include "ubifs.h"
Heiko Schocherff94bc42014-06-24 10:10:04 +020018#ifndef __UBOOT__
19#include <linux/slab.h>
20#include <linux/random.h>
21#include <linux/math64.h>
22#else
23
24#include <linux/compat.h>
25#include <linux/err.h>
26#include <ubi_uboot.h>
27#include <linux/stat.h>
28#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +010029
30/*
31 * Default journal size in logical eraseblocks as a percent of total
32 * flash size.
33 */
34#define DEFAULT_JNL_PERCENT 5
35
36/* Default maximum journal size in bytes */
37#define DEFAULT_MAX_JNL (32*1024*1024)
38
39/* Default indexing tree fanout */
40#define DEFAULT_FANOUT 8
41
42/* Default number of data journal heads */
43#define DEFAULT_JHEADS_CNT 1
44
45/* Default positions of different LEBs in the main area */
46#define DEFAULT_IDX_LEB 0
47#define DEFAULT_DATA_LEB 1
48#define DEFAULT_GC_LEB 2
49
50/* Default number of LEB numbers in LPT's save table */
51#define DEFAULT_LSAVE_CNT 256
52
53/* Default reserved pool size as a percent of maximum free space */
54#define DEFAULT_RP_PERCENT 5
55
56/* The default maximum size of reserved pool in bytes */
57#define DEFAULT_MAX_RP_SIZE (5*1024*1024)
58
59/* Default time granularity in nanoseconds */
60#define DEFAULT_TIME_GRAN 1000000000
61
Heiko Schocherff94bc42014-06-24 10:10:04 +020062#ifndef __UBOOT__
63/**
64 * create_default_filesystem - format empty UBI volume.
65 * @c: UBIFS file-system description object
66 *
67 * This function creates default empty file-system. Returns zero in case of
68 * success and a negative error code in case of failure.
69 */
70static int create_default_filesystem(struct ubifs_info *c)
71{
72 struct ubifs_sb_node *sup;
73 struct ubifs_mst_node *mst;
74 struct ubifs_idx_node *idx;
75 struct ubifs_branch *br;
76 struct ubifs_ino_node *ino;
77 struct ubifs_cs_node *cs;
78 union ubifs_key key;
79 int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;
80 int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
81 int min_leb_cnt = UBIFS_MIN_LEB_CNT;
82 long long tmp64, main_bytes;
83 __le64 tmp_le64;
84
85 /* Some functions called from here depend on the @c->key_len filed */
86 c->key_len = UBIFS_SK_LEN;
87
88 /*
89 * First of all, we have to calculate default file-system geometry -
90 * log size, journal size, etc.
91 */
92 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
93 /* We can first multiply then divide and have no overflow */
94 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
95 else
96 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
97
98 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
99 jnl_lebs = UBIFS_MIN_JNL_LEBS;
100 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
101 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
102
103 /*
104 * The log should be large enough to fit reference nodes for all bud
105 * LEBs. Because buds do not have to start from the beginning of LEBs
106 * (half of the LEB may contain committed data), the log should
107 * generally be larger, make it twice as large.
108 */
109 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
110 log_lebs = tmp / c->leb_size;
111 /* Plus one LEB reserved for commit */
112 log_lebs += 1;
113 if (c->leb_cnt - min_leb_cnt > 8) {
114 /* And some extra space to allow writes while committing */
115 log_lebs += 1;
116 min_leb_cnt += 1;
117 }
118
119 max_buds = jnl_lebs - log_lebs;
120 if (max_buds < UBIFS_MIN_BUD_LEBS)
121 max_buds = UBIFS_MIN_BUD_LEBS;
122
123 /*
124 * Orphan nodes are stored in a separate area. One node can store a lot
125 * of orphan inode numbers, but when new orphan comes we just add a new
126 * orphan node. At some point the nodes are consolidated into one
127 * orphan node.
128 */
129 orph_lebs = UBIFS_MIN_ORPH_LEBS;
130 if (c->leb_cnt - min_leb_cnt > 1)
131 /*
132 * For debugging purposes it is better to have at least 2
133 * orphan LEBs, because the orphan subsystem would need to do
134 * consolidations and would be stressed more.
135 */
136 orph_lebs += 1;
137
138 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
139 main_lebs -= orph_lebs;
140
141 lpt_first = UBIFS_LOG_LNUM + log_lebs;
142 c->lsave_cnt = DEFAULT_LSAVE_CNT;
143 c->max_leb_cnt = c->leb_cnt;
144 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
145 &big_lpt);
146 if (err)
147 return err;
148
149 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
150 lpt_first + lpt_lebs - 1);
151
152 main_first = c->leb_cnt - main_lebs;
153
154 /* Create default superblock */
155 tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
156 sup = kzalloc(tmp, GFP_KERNEL);
157 if (!sup)
158 return -ENOMEM;
159
160 tmp64 = (long long)max_buds * c->leb_size;
161 if (big_lpt)
162 sup_flags |= UBIFS_FLG_BIGLPT;
163
164 sup->ch.node_type = UBIFS_SB_NODE;
165 sup->key_hash = UBIFS_KEY_HASH_R5;
166 sup->flags = cpu_to_le32(sup_flags);
167 sup->min_io_size = cpu_to_le32(c->min_io_size);
168 sup->leb_size = cpu_to_le32(c->leb_size);
169 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
170 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
171 sup->max_bud_bytes = cpu_to_le64(tmp64);
172 sup->log_lebs = cpu_to_le32(log_lebs);
173 sup->lpt_lebs = cpu_to_le32(lpt_lebs);
174 sup->orph_lebs = cpu_to_le32(orph_lebs);
175 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
176 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
177 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
178 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
179 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
180 if (c->mount_opts.override_compr)
181 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
182 else
183 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
184
185 generate_random_uuid(sup->uuid);
186
187 main_bytes = (long long)main_lebs * c->leb_size;
188 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
189 if (tmp64 > DEFAULT_MAX_RP_SIZE)
190 tmp64 = DEFAULT_MAX_RP_SIZE;
191 sup->rp_size = cpu_to_le64(tmp64);
192 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);
193
194 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0);
195 kfree(sup);
196 if (err)
197 return err;
198
199 dbg_gen("default superblock created at LEB 0:0");
200
201 /* Create default master node */
202 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
203 if (!mst)
204 return -ENOMEM;
205
206 mst->ch.node_type = UBIFS_MST_NODE;
207 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
208 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
209 mst->cmt_no = 0;
210 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
211 mst->root_offs = 0;
212 tmp = ubifs_idx_node_sz(c, 1);
213 mst->root_len = cpu_to_le32(tmp);
214 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
215 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
216 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
217 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
218 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
219 mst->lpt_offs = cpu_to_le32(c->lpt_offs);
220 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
221 mst->nhead_offs = cpu_to_le32(c->nhead_offs);
222 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
223 mst->ltab_offs = cpu_to_le32(c->ltab_offs);
224 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
225 mst->lsave_offs = cpu_to_le32(c->lsave_offs);
226 mst->lscan_lnum = cpu_to_le32(main_first);
227 mst->empty_lebs = cpu_to_le32(main_lebs - 2);
228 mst->idx_lebs = cpu_to_le32(1);
229 mst->leb_cnt = cpu_to_le32(c->leb_cnt);
230
231 /* Calculate lprops statistics */
232 tmp64 = main_bytes;
233 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
234 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
235 mst->total_free = cpu_to_le64(tmp64);
236
237 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
238 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
239 UBIFS_INO_NODE_SZ;
240 tmp64 += ino_waste;
241 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
242 mst->total_dirty = cpu_to_le64(tmp64);
243
244 /* The indexing LEB does not contribute to dark space */
245 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);
246 mst->total_dark = cpu_to_le64(tmp64);
247
248 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
249
250 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0);
251 if (err) {
252 kfree(mst);
253 return err;
254 }
255 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,
256 0);
257 kfree(mst);
258 if (err)
259 return err;
260
261 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
262
263 /* Create the root indexing node */
264 tmp = ubifs_idx_node_sz(c, 1);
265 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
266 if (!idx)
267 return -ENOMEM;
268
269 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
270 c->key_hash = key_r5_hash;
271
272 idx->ch.node_type = UBIFS_IDX_NODE;
273 idx->child_cnt = cpu_to_le16(1);
274 ino_key_init(c, &key, UBIFS_ROOT_INO);
275 br = ubifs_idx_branch(c, idx, 0);
276 key_write_idx(c, &key, &br->key);
277 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
278 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
279 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0);
280 kfree(idx);
281 if (err)
282 return err;
283
284 dbg_gen("default root indexing node created LEB %d:0",
285 main_first + DEFAULT_IDX_LEB);
286
287 /* Create default root inode */
288 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
289 ino = kzalloc(tmp, GFP_KERNEL);
290 if (!ino)
291 return -ENOMEM;
292
293 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
294 ino->ch.node_type = UBIFS_INO_NODE;
295 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
296 ino->nlink = cpu_to_le32(2);
297 tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
298 ino->atime_sec = tmp_le64;
299 ino->ctime_sec = tmp_le64;
300 ino->mtime_sec = tmp_le64;
301 ino->atime_nsec = 0;
302 ino->ctime_nsec = 0;
303 ino->mtime_nsec = 0;
304 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
305 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
306
307 /* Set compression enabled by default */
308 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
309
310 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
311 main_first + DEFAULT_DATA_LEB, 0);
312 kfree(ino);
313 if (err)
314 return err;
315
316 dbg_gen("root inode created at LEB %d:0",
317 main_first + DEFAULT_DATA_LEB);
318
319 /*
320 * The first node in the log has to be the commit start node. This is
321 * always the case during normal file-system operation. Write a fake
322 * commit start node to the log.
323 */
324 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
325 cs = kzalloc(tmp, GFP_KERNEL);
326 if (!cs)
327 return -ENOMEM;
328
329 cs->ch.node_type = UBIFS_CS_NODE;
330 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);
331 kfree(cs);
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200332 if (err)
333 return err;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200334
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200335 ubifs_msg(c, "default file-system created");
Heiko Schocherff94bc42014-06-24 10:10:04 +0200336 return 0;
337}
338#endif
339
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100340/**
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) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200366 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100367 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) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200372 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100373 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) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200394 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200395 c->leb_cnt, c->vi.size, min_leb_cnt);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100396 goto failed;
397 }
398
399 if (c->max_leb_cnt < c->leb_cnt) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200400 ubifs_err(c, "max. LEB count %d less than LEB count %d",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100401 c->max_leb_cnt, c->leb_cnt);
402 goto failed;
403 }
404
405 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200406 ubifs_err(c, "too few main LEBs count %d, must be at least %d",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200407 c->main_lebs, UBIFS_MIN_MAIN_LEBS);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100408 goto failed;
409 }
410
Heiko Schocherff94bc42014-06-24 10:10:04 +0200411 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;
412 if (c->max_bud_bytes < max_bytes) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200413 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200414 c->max_bud_bytes, max_bytes);
415 goto failed;
416 }
417
418 max_bytes = (long long)c->leb_size * c->main_lebs;
419 if (c->max_bud_bytes > max_bytes) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200420 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area",
Heiko Schocherff94bc42014-06-24 10:10:04 +0200421 c->max_bud_bytes, max_bytes);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100422 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
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200450 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100451 err = 13;
452 goto failed;
453 }
454
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100455 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:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200469 ubifs_err(c, "bad superblock, error %d", err);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200470 ubifs_dump_node(c, sup);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100471 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
Heiko Schocherff94bc42014-06-24 10:10:04 +0200479 * code. Note, the user of this function is responsible of kfree()'ing the
480 * returned superblock buffer.
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100481 */
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/**
Heiko Schocherff94bc42014-06-24 10:10:04 +0200502 * 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);
513 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);
514}
515
516/**
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100517 * 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) {
Heiko Schocherff94bc42014-06-24 10:10:04 +0200530#ifndef __UBOOT__
531 err = create_default_filesystem(c);
532 if (err)
533 return err;
534#else
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100535 printf("No UBIFS filesystem found!\n");
536 return -1;
Heiko Schocherff94bc42014-06-24 10:10:04 +0200537#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100538 }
539
540 sup = ubifs_read_sb_node(c);
541 if (IS_ERR(sup))
542 return PTR_ERR(sup);
543
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100544 c->fmt_version = le32_to_cpu(sup->fmt_version);
545 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);
546
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100547 /*
548 * The software supports all previous versions but not future versions,
549 * due to the unavailability of time-travelling equipment.
550 */
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100551 if (c->fmt_version > UBIFS_FORMAT_VERSION) {
Heiko Schocherff94bc42014-06-24 10:10:04 +0200552 ubifs_assert(!c->ro_media || c->ro_mount);
553 if (!c->ro_mount ||
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100554 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200555 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 +0200556 c->fmt_version, c->ro_compat_version,
557 UBIFS_FORMAT_VERSION,
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100558 UBIFS_RO_COMPAT_VERSION);
559 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200560 ubifs_msg(c, "only R/O mounting is possible");
Artem Bityutskiyfebd7e42009-03-27 10:21:14 +0100561 err = -EROFS;
562 } else
563 err = -EINVAL;
564 goto out;
565 }
566
567 /*
568 * The FS is mounted R/O, and the media format is
569 * R/O-compatible with the UBIFS implementation, so we can
570 * mount.
571 */
572 c->rw_incompat = 1;
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100573 }
574
575 if (c->fmt_version < 3) {
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200576 ubifs_err(c, "on-flash format version %d is not supported",
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100577 c->fmt_version);
578 err = -EINVAL;
579 goto out;
580 }
581
582 switch (sup->key_hash) {
583 case UBIFS_KEY_HASH_R5:
584 c->key_hash = key_r5_hash;
585 c->key_hash_type = UBIFS_KEY_HASH_R5;
586 break;
587
588 case UBIFS_KEY_HASH_TEST:
589 c->key_hash = key_test_hash;
590 c->key_hash_type = UBIFS_KEY_HASH_TEST;
591 break;
592 };
593
594 c->key_fmt = sup->key_fmt;
595
596 switch (c->key_fmt) {
597 case UBIFS_SIMPLE_KEY_FMT:
598 c->key_len = UBIFS_SK_LEN;
599 break;
600 default:
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200601 ubifs_err(c, "unsupported key format");
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100602 err = -EINVAL;
603 goto out;
604 }
605
606 c->leb_cnt = le32_to_cpu(sup->leb_cnt);
607 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
608 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
609 c->log_lebs = le32_to_cpu(sup->log_lebs);
610 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
611 c->orph_lebs = le32_to_cpu(sup->orph_lebs);
612 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
613 c->fanout = le32_to_cpu(sup->fanout);
614 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100615 c->rp_size = le64_to_cpu(sup->rp_size);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200616#ifndef __UBOOT__
617 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));
618 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));
619#else
620 c->rp_uid.val = le32_to_cpu(sup->rp_uid);
621 c->rp_gid.val = le32_to_cpu(sup->rp_gid);
622#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100623 sup_flags = le32_to_cpu(sup->flags);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200624 if (!c->mount_opts.override_compr)
625 c->default_compr = le16_to_cpu(sup->default_compr);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100626
627 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
628 memcpy(&c->uuid, &sup->uuid, 16);
629 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200630 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100631
632 /* Automatically increase file system size to the maximum size */
633 c->old_leb_cnt = c->leb_cnt;
634 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
635 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
Heiko Schocherff94bc42014-06-24 10:10:04 +0200636 if (c->ro_mount)
637 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
638 c->old_leb_cnt, c->leb_cnt);
639#ifndef __UBOOT__
640 else {
641 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
642 c->old_leb_cnt, c->leb_cnt);
643 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
644 err = ubifs_write_sb_node(c, sup);
645 if (err)
646 goto out;
647 c->old_leb_cnt = c->leb_cnt;
648 }
649#endif
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100650 }
651
652 c->log_bytes = (long long)c->log_lebs * c->leb_size;
653 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
654 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
655 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
656 c->orph_first = c->lpt_last + 1;
657 c->orph_last = c->orph_first + c->orph_lebs - 1;
658 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
659 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
660 c->main_first = c->leb_cnt - c->main_lebs;
Stefan Roese9eefe2a2009-03-19 15:35:05 +0100661
662 err = validate_sb(c, sup);
663out:
664 kfree(sup);
665 return err;
666}
Heiko Schocherff94bc42014-06-24 10:10:04 +0200667
668/**
669 * fixup_leb - fixup/unmap an LEB containing free space.
670 * @c: UBIFS file-system description object
671 * @lnum: the LEB number to fix up
672 * @len: number of used bytes in LEB (starting at offset 0)
673 *
674 * This function reads the contents of the given LEB number @lnum, then fixes
675 * it up, so that empty min. I/O units in the end of LEB are actually erased on
676 * flash (rather than being just all-0xff real data). If the LEB is completely
677 * empty, it is simply unmapped.
678 */
679static int fixup_leb(struct ubifs_info *c, int lnum, int len)
680{
681 int err;
682
683 ubifs_assert(len >= 0);
684 ubifs_assert(len % c->min_io_size == 0);
685 ubifs_assert(len < c->leb_size);
686
687 if (len == 0) {
688 dbg_mnt("unmap empty LEB %d", lnum);
689 return ubifs_leb_unmap(c, lnum);
690 }
691
692 dbg_mnt("fixup LEB %d, data len %d", lnum, len);
693 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);
694 if (err)
695 return err;
696
697 return ubifs_leb_change(c, lnum, c->sbuf, len);
698}
699
700/**
701 * fixup_free_space - find & remap all LEBs containing free space.
702 * @c: UBIFS file-system description object
703 *
704 * This function walks through all LEBs in the filesystem and fiexes up those
705 * containing free/empty space.
706 */
707static int fixup_free_space(struct ubifs_info *c)
708{
709 int lnum, err = 0;
710 struct ubifs_lprops *lprops;
711
712 ubifs_get_lprops(c);
713
714 /* Fixup LEBs in the master area */
715 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {
716 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);
717 if (err)
718 goto out;
719 }
720
721 /* Unmap unused log LEBs */
722 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);
723 while (lnum != c->ltail_lnum) {
724 err = fixup_leb(c, lnum, 0);
725 if (err)
726 goto out;
727 lnum = ubifs_next_log_lnum(c, lnum);
728 }
729
730 /*
731 * Fixup the log head which contains the only a CS node at the
732 * beginning.
733 */
734 err = fixup_leb(c, c->lhead_lnum,
735 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));
736 if (err)
737 goto out;
738
739 /* Fixup LEBs in the LPT area */
740 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
741 int free = c->ltab[lnum - c->lpt_first].free;
742
743 if (free > 0) {
744 err = fixup_leb(c, lnum, c->leb_size - free);
745 if (err)
746 goto out;
747 }
748 }
749
750 /* Unmap LEBs in the orphans area */
751 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
752 err = fixup_leb(c, lnum, 0);
753 if (err)
754 goto out;
755 }
756
757 /* Fixup LEBs in the main area */
758 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
759 lprops = ubifs_lpt_lookup(c, lnum);
760 if (IS_ERR(lprops)) {
761 err = PTR_ERR(lprops);
762 goto out;
763 }
764
765 if (lprops->free > 0) {
766 err = fixup_leb(c, lnum, c->leb_size - lprops->free);
767 if (err)
768 goto out;
769 }
770 }
771
772out:
773 ubifs_release_lprops(c);
774 return err;
775}
776
777/**
778 * ubifs_fixup_free_space - find & fix all LEBs with free space.
779 * @c: UBIFS file-system description object
780 *
781 * This function fixes up LEBs containing free space on first mount, if the
782 * appropriate flag was set when the FS was created. Each LEB with one or more
783 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure
784 * the free space is actually erased. E.g., this is necessary for some NAND
785 * chips, since the free space may have been programmed like real "0xff" data
786 * (generating a non-0xff ECC), causing future writes to the not-really-erased
787 * NAND pages to behave badly. After the space is fixed up, the superblock flag
788 * is cleared, so that this is skipped for all future mounts.
789 */
790int ubifs_fixup_free_space(struct ubifs_info *c)
791{
792 int err;
793 struct ubifs_sb_node *sup;
794
795 ubifs_assert(c->space_fixup);
796 ubifs_assert(!c->ro_mount);
797
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200798 ubifs_msg(c, "start fixing up free space");
Heiko Schocherff94bc42014-06-24 10:10:04 +0200799
800 err = fixup_free_space(c);
801 if (err)
802 return err;
803
804 sup = ubifs_read_sb_node(c);
805 if (IS_ERR(sup))
806 return PTR_ERR(sup);
807
808 /* Free-space fixup is no longer required */
809 c->space_fixup = 0;
810 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);
811
812 err = ubifs_write_sb_node(c, sup);
813 kfree(sup);
814 if (err)
815 return err;
816
Heiko Schocher0195a7b2015-10-22 06:19:21 +0200817 ubifs_msg(c, "free space fixup complete");
Heiko Schocherff94bc42014-06-24 10:10:04 +0200818 return err;
819}