xref: /openbmc/linux/fs/ubifs/sb.c (revision f30828a6)
1 /*
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"
30 #include <linux/random.h>
31 
32 /*
33  * Default journal size in logical eraseblocks as a percent of total
34  * flash size.
35  */
36 #define DEFAULT_JNL_PERCENT 5
37 
38 /* Default maximum journal size in bytes */
39 #define DEFAULT_MAX_JNL (32*1024*1024)
40 
41 /* Default indexing tree fanout */
42 #define DEFAULT_FANOUT 8
43 
44 /* Default number of data journal heads */
45 #define DEFAULT_JHEADS_CNT 1
46 
47 /* Default positions of different LEBs in the main area */
48 #define DEFAULT_IDX_LEB  0
49 #define DEFAULT_DATA_LEB 1
50 #define DEFAULT_GC_LEB   2
51 
52 /* Default number of LEB numbers in LPT's save table */
53 #define DEFAULT_LSAVE_CNT 256
54 
55 /* Default reserved pool size as a percent of maximum free space */
56 #define DEFAULT_RP_PERCENT 5
57 
58 /* The default maximum size of reserved pool in bytes */
59 #define DEFAULT_MAX_RP_SIZE (5*1024*1024)
60 
61 /* Default time granularity in nanoseconds */
62 #define DEFAULT_TIME_GRAN 1000000000
63 
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  */
71 static 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 	uint64_t tmp64, main_bytes;
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 #ifdef CONFIG_UBIFS_FS_DEBUG
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 #endif
139 
140 	main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
141 	main_lebs -= orph_lebs;
142 
143 	lpt_first = UBIFS_LOG_LNUM + log_lebs;
144 	c->lsave_cnt = DEFAULT_LSAVE_CNT;
145 	c->max_leb_cnt = c->leb_cnt;
146 	err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
147 				    &big_lpt);
148 	if (err)
149 		return err;
150 
151 	dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
152 		lpt_first + lpt_lebs - 1);
153 
154 	main_first = c->leb_cnt - main_lebs;
155 
156 	/* Create default superblock */
157 	tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
158 	sup = kzalloc(tmp, GFP_KERNEL);
159 	if (!sup)
160 		return -ENOMEM;
161 
162 	tmp64 = (uint64_t)max_buds * c->leb_size;
163 	if (big_lpt)
164 		sup_flags |= UBIFS_FLG_BIGLPT;
165 
166 	sup->ch.node_type  = UBIFS_SB_NODE;
167 	sup->key_hash      = UBIFS_KEY_HASH_R5;
168 	sup->flags         = cpu_to_le32(sup_flags);
169 	sup->min_io_size   = cpu_to_le32(c->min_io_size);
170 	sup->leb_size      = cpu_to_le32(c->leb_size);
171 	sup->leb_cnt       = cpu_to_le32(c->leb_cnt);
172 	sup->max_leb_cnt   = cpu_to_le32(c->max_leb_cnt);
173 	sup->max_bud_bytes = cpu_to_le64(tmp64);
174 	sup->log_lebs      = cpu_to_le32(log_lebs);
175 	sup->lpt_lebs      = cpu_to_le32(lpt_lebs);
176 	sup->orph_lebs     = cpu_to_le32(orph_lebs);
177 	sup->jhead_cnt     = cpu_to_le32(DEFAULT_JHEADS_CNT);
178 	sup->fanout        = cpu_to_le32(DEFAULT_FANOUT);
179 	sup->lsave_cnt     = cpu_to_le32(c->lsave_cnt);
180 	sup->fmt_version   = cpu_to_le32(UBIFS_FORMAT_VERSION);
181 	sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
182 	sup->time_gran     = cpu_to_le32(DEFAULT_TIME_GRAN);
183 
184 	generate_random_uuid(sup->uuid);
185 
186 	main_bytes = (uint64_t)main_lebs * c->leb_size;
187 	tmp64 = main_bytes * DEFAULT_RP_PERCENT;
188 	do_div(tmp64, 100);
189 	if (tmp64 > DEFAULT_MAX_RP_SIZE)
190 		tmp64 = DEFAULT_MAX_RP_SIZE;
191 	sup->rp_size = cpu_to_le64(tmp64);
192 
193 	err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM);
194 	kfree(sup);
195 	if (err)
196 		return err;
197 
198 	dbg_gen("default superblock created at LEB 0:0");
199 
200 	/* Create default master node */
201 	mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
202 	if (!mst)
203 		return -ENOMEM;
204 
205 	mst->ch.node_type = UBIFS_MST_NODE;
206 	mst->log_lnum     = cpu_to_le32(UBIFS_LOG_LNUM);
207 	mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
208 	mst->cmt_no       = 0;
209 	mst->root_lnum    = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
210 	mst->root_offs    = 0;
211 	tmp = ubifs_idx_node_sz(c, 1);
212 	mst->root_len     = cpu_to_le32(tmp);
213 	mst->gc_lnum      = cpu_to_le32(main_first + DEFAULT_GC_LEB);
214 	mst->ihead_lnum   = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
215 	mst->ihead_offs   = cpu_to_le32(ALIGN(tmp, c->min_io_size));
216 	mst->index_size   = cpu_to_le64(ALIGN(tmp, 8));
217 	mst->lpt_lnum     = cpu_to_le32(c->lpt_lnum);
218 	mst->lpt_offs     = cpu_to_le32(c->lpt_offs);
219 	mst->nhead_lnum   = cpu_to_le32(c->nhead_lnum);
220 	mst->nhead_offs   = cpu_to_le32(c->nhead_offs);
221 	mst->ltab_lnum    = cpu_to_le32(c->ltab_lnum);
222 	mst->ltab_offs    = cpu_to_le32(c->ltab_offs);
223 	mst->lsave_lnum   = cpu_to_le32(c->lsave_lnum);
224 	mst->lsave_offs   = cpu_to_le32(c->lsave_offs);
225 	mst->lscan_lnum   = cpu_to_le32(main_first);
226 	mst->empty_lebs   = cpu_to_le32(main_lebs - 2);
227 	mst->idx_lebs     = cpu_to_le32(1);
228 	mst->leb_cnt      = cpu_to_le32(c->leb_cnt);
229 
230 	/* Calculate lprops statistics */
231 	tmp64 = main_bytes;
232 	tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
233 	tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
234 	mst->total_free = cpu_to_le64(tmp64);
235 
236 	tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
237 	ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
238 			  UBIFS_INO_NODE_SZ;
239 	tmp64 += ino_waste;
240 	tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
241 	mst->total_dirty = cpu_to_le64(tmp64);
242 
243 	/*  The indexing LEB does not contribute to dark space */
244 	tmp64 = (c->main_lebs - 1) * c->dark_wm;
245 	mst->total_dark = cpu_to_le64(tmp64);
246 
247 	mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
248 
249 	err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
250 			       UBI_UNKNOWN);
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, 0,
256 			       UBI_UNKNOWN);
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 			       UBI_UNKNOWN);
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 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
299 	ino->atime_sec   = tmp;
300 	ino->ctime_sec   = tmp;
301 	ino->mtime_sec   = tmp;
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 			       UBI_UNKNOWN);
314 	kfree(ino);
315 	if (err)
316 		return err;
317 
318 	dbg_gen("root inode created at LEB %d:0",
319 		main_first + DEFAULT_DATA_LEB);
320 
321 	/*
322 	 * The first node in the log has to be the commit start node. This is
323 	 * always the case during normal file-system operation. Write a fake
324 	 * commit start node to the log.
325 	 */
326 	tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
327 	cs = kzalloc(tmp, GFP_KERNEL);
328 	if (!cs)
329 		return -ENOMEM;
330 
331 	cs->ch.node_type = UBIFS_CS_NODE;
332 	err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM,
333 			       0, UBI_UNKNOWN);
334 	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  */
350 static 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) {
394 		ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, "
395 			  "%d minimum required", c->leb_cnt, c->vi.size,
396 			  min_leb_cnt);
397 		goto failed;
398 	}
399 
400 	if (c->max_leb_cnt < c->leb_cnt) {
401 		ubifs_err("max. LEB count %d less than LEB count %d",
402 			  c->max_leb_cnt, c->leb_cnt);
403 		goto failed;
404 	}
405 
406 	if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
407 		err = 7;
408 		goto failed;
409 	}
410 
411 	if (c->max_bud_bytes < (long long)c->leb_size * UBIFS_MIN_BUD_LEBS ||
412 	    c->max_bud_bytes > (long long)c->leb_size * c->main_lebs) {
413 		err = 8;
414 		goto failed;
415 	}
416 
417 	if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
418 	    c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
419 		err = 9;
420 		goto failed;
421 	}
422 
423 	if (c->fanout < UBIFS_MIN_FANOUT ||
424 	    ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
425 		err = 10;
426 		goto failed;
427 	}
428 
429 	if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
430 	    c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
431 	    c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
432 		err = 11;
433 		goto failed;
434 	}
435 
436 	if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
437 	    c->orph_lebs + c->main_lebs != c->leb_cnt) {
438 		err = 12;
439 		goto failed;
440 	}
441 
442 	if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
443 		err = 13;
444 		goto failed;
445 	}
446 
447 	max_bytes = c->main_lebs * (long long)c->leb_size;
448 	if (c->rp_size < 0 || max_bytes < c->rp_size) {
449 		err = 14;
450 		goto failed;
451 	}
452 
453 	if (le32_to_cpu(sup->time_gran) > 1000000000 ||
454 	    le32_to_cpu(sup->time_gran) < 1) {
455 		err = 15;
456 		goto failed;
457 	}
458 
459 	return 0;
460 
461 failed:
462 	ubifs_err("bad superblock, error %d", err);
463 	dbg_dump_node(c, sup);
464 	return -EINVAL;
465 }
466 
467 /**
468  * ubifs_read_sb_node - read superblock node.
469  * @c: UBIFS file-system description object
470  *
471  * This function returns a pointer to the superblock node or a negative error
472  * code.
473  */
474 struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
475 {
476 	struct ubifs_sb_node *sup;
477 	int err;
478 
479 	sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
480 	if (!sup)
481 		return ERR_PTR(-ENOMEM);
482 
483 	err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
484 			      UBIFS_SB_LNUM, 0);
485 	if (err) {
486 		kfree(sup);
487 		return ERR_PTR(err);
488 	}
489 
490 	return sup;
491 }
492 
493 /**
494  * ubifs_write_sb_node - write superblock node.
495  * @c: UBIFS file-system description object
496  * @sup: superblock node read with 'ubifs_read_sb_node()'
497  *
498  * This function returns %0 on success and a negative error code on failure.
499  */
500 int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
501 {
502 	int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
503 
504 	ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
505 	return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM);
506 }
507 
508 /**
509  * ubifs_read_superblock - read superblock.
510  * @c: UBIFS file-system description object
511  *
512  * This function finds, reads and checks the superblock. If an empty UBI volume
513  * is being mounted, this function creates default superblock. Returns zero in
514  * case of success, and a negative error code in case of failure.
515  */
516 int ubifs_read_superblock(struct ubifs_info *c)
517 {
518 	int err, sup_flags;
519 	struct ubifs_sb_node *sup;
520 
521 	if (c->empty) {
522 		err = create_default_filesystem(c);
523 		if (err)
524 			return err;
525 	}
526 
527 	sup = ubifs_read_sb_node(c);
528 	if (IS_ERR(sup))
529 		return PTR_ERR(sup);
530 
531 	/*
532 	 * The software supports all previous versions but not future versions,
533 	 * due to the unavailability of time-travelling equipment.
534 	 */
535 	c->fmt_version = le32_to_cpu(sup->fmt_version);
536 	if (c->fmt_version > UBIFS_FORMAT_VERSION) {
537 		ubifs_err("on-flash format version is %d, but software only "
538 			  "supports up to version %d", c->fmt_version,
539 			  UBIFS_FORMAT_VERSION);
540 		err = -EINVAL;
541 		goto out;
542 	}
543 
544 	if (c->fmt_version < 3) {
545 		ubifs_err("on-flash format version %d is not supported",
546 			  c->fmt_version);
547 		err = -EINVAL;
548 		goto out;
549 	}
550 
551 	switch (sup->key_hash) {
552 	case UBIFS_KEY_HASH_R5:
553 		c->key_hash = key_r5_hash;
554 		c->key_hash_type = UBIFS_KEY_HASH_R5;
555 		break;
556 
557 	case UBIFS_KEY_HASH_TEST:
558 		c->key_hash = key_test_hash;
559 		c->key_hash_type = UBIFS_KEY_HASH_TEST;
560 		break;
561 	};
562 
563 	c->key_fmt = sup->key_fmt;
564 
565 	switch (c->key_fmt) {
566 	case UBIFS_SIMPLE_KEY_FMT:
567 		c->key_len = UBIFS_SK_LEN;
568 		break;
569 	default:
570 		ubifs_err("unsupported key format");
571 		err = -EINVAL;
572 		goto out;
573 	}
574 
575 	c->leb_cnt       = le32_to_cpu(sup->leb_cnt);
576 	c->max_leb_cnt   = le32_to_cpu(sup->max_leb_cnt);
577 	c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
578 	c->log_lebs      = le32_to_cpu(sup->log_lebs);
579 	c->lpt_lebs      = le32_to_cpu(sup->lpt_lebs);
580 	c->orph_lebs     = le32_to_cpu(sup->orph_lebs);
581 	c->jhead_cnt     = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
582 	c->fanout        = le32_to_cpu(sup->fanout);
583 	c->lsave_cnt     = le32_to_cpu(sup->lsave_cnt);
584 	c->default_compr = le16_to_cpu(sup->default_compr);
585 	c->rp_size       = le64_to_cpu(sup->rp_size);
586 	c->rp_uid        = le32_to_cpu(sup->rp_uid);
587 	c->rp_gid        = le32_to_cpu(sup->rp_gid);
588 	sup_flags        = le32_to_cpu(sup->flags);
589 
590 	c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
591 
592 	memcpy(&c->uuid, &sup->uuid, 16);
593 
594 	c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
595 
596 	/* Automatically increase file system size to the maximum size */
597 	c->old_leb_cnt = c->leb_cnt;
598 	if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
599 		c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
600 		if (c->vfs_sb->s_flags & MS_RDONLY)
601 			dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
602 				c->old_leb_cnt,	c->leb_cnt);
603 		else {
604 			dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
605 				c->old_leb_cnt, c->leb_cnt);
606 			sup->leb_cnt = cpu_to_le32(c->leb_cnt);
607 			err = ubifs_write_sb_node(c, sup);
608 			if (err)
609 				goto out;
610 			c->old_leb_cnt = c->leb_cnt;
611 		}
612 	}
613 
614 	c->log_bytes = (long long)c->log_lebs * c->leb_size;
615 	c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
616 	c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
617 	c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
618 	c->orph_first = c->lpt_last + 1;
619 	c->orph_last = c->orph_first + c->orph_lebs - 1;
620 	c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
621 	c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
622 	c->main_first = c->leb_cnt - c->main_lebs;
623 	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
624 
625 	err = validate_sb(c, sup);
626 out:
627 	kfree(sup);
628 	return err;
629 }
630