1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * This file is part of UBIFS. |
4 | * |
5 | * Copyright (C) 2006-2008 Nokia Corporation. |
6 | * |
7 | * 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" |
18 | #include <linux/slab.h> |
19 | #include <linux/math64.h> |
20 | #include <linux/uuid.h> |
21 | |
22 | /* |
23 | * Default journal size in logical eraseblocks as a percent of total |
24 | * flash size. |
25 | */ |
26 | #define DEFAULT_JNL_PERCENT 5 |
27 | |
28 | /* Default maximum journal size in bytes */ |
29 | #define DEFAULT_MAX_JNL (32*1024*1024) |
30 | |
31 | /* Default indexing tree fanout */ |
32 | #define DEFAULT_FANOUT 8 |
33 | |
34 | /* Default number of data journal heads */ |
35 | #define DEFAULT_JHEADS_CNT 1 |
36 | |
37 | /* Default positions of different LEBs in the main area */ |
38 | #define DEFAULT_IDX_LEB 0 |
39 | #define DEFAULT_DATA_LEB 1 |
40 | #define DEFAULT_GC_LEB 2 |
41 | |
42 | /* Default number of LEB numbers in LPT's save table */ |
43 | #define DEFAULT_LSAVE_CNT 256 |
44 | |
45 | /* Default reserved pool size as a percent of maximum free space */ |
46 | #define DEFAULT_RP_PERCENT 5 |
47 | |
48 | /* The default maximum size of reserved pool in bytes */ |
49 | #define DEFAULT_MAX_RP_SIZE (5*1024*1024) |
50 | |
51 | /* Default time granularity in nanoseconds */ |
52 | #define DEFAULT_TIME_GRAN 1000000000 |
53 | |
54 | static int get_default_compressor(struct ubifs_info *c) |
55 | { |
56 | if (ubifs_compr_present(c, compr_type: UBIFS_COMPR_ZSTD)) |
57 | return UBIFS_COMPR_ZSTD; |
58 | |
59 | if (ubifs_compr_present(c, compr_type: UBIFS_COMPR_LZO)) |
60 | return UBIFS_COMPR_LZO; |
61 | |
62 | if (ubifs_compr_present(c, compr_type: UBIFS_COMPR_ZLIB)) |
63 | return UBIFS_COMPR_ZLIB; |
64 | |
65 | return UBIFS_COMPR_NONE; |
66 | } |
67 | |
68 | /** |
69 | * create_default_filesystem - format empty UBI volume. |
70 | * @c: UBIFS file-system description object |
71 | * |
72 | * This function creates default empty file-system. Returns zero in case of |
73 | * success and a negative error code in case of failure. |
74 | */ |
75 | static int create_default_filesystem(struct ubifs_info *c) |
76 | { |
77 | struct ubifs_sb_node *sup; |
78 | struct ubifs_mst_node *mst; |
79 | struct ubifs_idx_node *idx; |
80 | struct ubifs_branch *br; |
81 | struct ubifs_ino_node *ino; |
82 | struct ubifs_cs_node *cs; |
83 | union ubifs_key key; |
84 | int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; |
85 | int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; |
86 | int min_leb_cnt = UBIFS_MIN_LEB_CNT; |
87 | int idx_node_size; |
88 | long long tmp64, main_bytes; |
89 | __le64 tmp_le64; |
90 | struct timespec64 ts; |
91 | u8 hash[UBIFS_HASH_ARR_SZ]; |
92 | u8 hash_lpt[UBIFS_HASH_ARR_SZ]; |
93 | |
94 | /* Some functions called from here depend on the @c->key_len filed */ |
95 | c->key_len = UBIFS_SK_LEN; |
96 | |
97 | /* |
98 | * First of all, we have to calculate default file-system geometry - |
99 | * log size, journal size, etc. |
100 | */ |
101 | if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) |
102 | /* We can first multiply then divide and have no overflow */ |
103 | jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; |
104 | else |
105 | jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; |
106 | |
107 | if (jnl_lebs < UBIFS_MIN_JNL_LEBS) |
108 | jnl_lebs = UBIFS_MIN_JNL_LEBS; |
109 | if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) |
110 | jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; |
111 | |
112 | /* |
113 | * The log should be large enough to fit reference nodes for all bud |
114 | * LEBs. Because buds do not have to start from the beginning of LEBs |
115 | * (half of the LEB may contain committed data), the log should |
116 | * generally be larger, make it twice as large. |
117 | */ |
118 | tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; |
119 | log_lebs = tmp / c->leb_size; |
120 | /* Plus one LEB reserved for commit */ |
121 | log_lebs += 1; |
122 | if (c->leb_cnt - min_leb_cnt > 8) { |
123 | /* And some extra space to allow writes while committing */ |
124 | log_lebs += 1; |
125 | min_leb_cnt += 1; |
126 | } |
127 | |
128 | max_buds = jnl_lebs - log_lebs; |
129 | if (max_buds < UBIFS_MIN_BUD_LEBS) |
130 | max_buds = UBIFS_MIN_BUD_LEBS; |
131 | |
132 | /* |
133 | * Orphan nodes are stored in a separate area. One node can store a lot |
134 | * of orphan inode numbers, but when new orphan comes we just add a new |
135 | * orphan node. At some point the nodes are consolidated into one |
136 | * orphan node. |
137 | */ |
138 | orph_lebs = UBIFS_MIN_ORPH_LEBS; |
139 | if (c->leb_cnt - min_leb_cnt > 1) |
140 | /* |
141 | * For debugging purposes it is better to have at least 2 |
142 | * orphan LEBs, because the orphan subsystem would need to do |
143 | * consolidations and would be stressed more. |
144 | */ |
145 | orph_lebs += 1; |
146 | |
147 | main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; |
148 | main_lebs -= orph_lebs; |
149 | |
150 | lpt_first = UBIFS_LOG_LNUM + log_lebs; |
151 | c->lsave_cnt = DEFAULT_LSAVE_CNT; |
152 | c->max_leb_cnt = c->leb_cnt; |
153 | err = ubifs_create_dflt_lpt(c, main_lebs: &main_lebs, lpt_first, lpt_lebs: &lpt_lebs, |
154 | big_lpt: &big_lpt, hash: hash_lpt); |
155 | if (err) |
156 | return err; |
157 | |
158 | dbg_gen("LEB Properties Tree created (LEBs %d-%d)" , lpt_first, |
159 | lpt_first + lpt_lebs - 1); |
160 | |
161 | main_first = c->leb_cnt - main_lebs; |
162 | |
163 | sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL); |
164 | mst = kzalloc(size: c->mst_node_alsz, GFP_KERNEL); |
165 | idx_node_size = ubifs_idx_node_sz(c, child_cnt: 1); |
166 | idx = kzalloc(ALIGN(idx_node_size, c->min_io_size), GFP_KERNEL); |
167 | ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); |
168 | cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL); |
169 | |
170 | if (!sup || !mst || !idx || !ino || !cs) { |
171 | err = -ENOMEM; |
172 | goto out; |
173 | } |
174 | |
175 | /* Create default superblock */ |
176 | |
177 | tmp64 = (long long)max_buds * c->leb_size; |
178 | if (big_lpt) |
179 | sup_flags |= UBIFS_FLG_BIGLPT; |
180 | if (ubifs_default_version > 4) |
181 | sup_flags |= UBIFS_FLG_DOUBLE_HASH; |
182 | |
183 | if (ubifs_authenticated(c)) { |
184 | sup_flags |= UBIFS_FLG_AUTHENTICATION; |
185 | sup->hash_algo = cpu_to_le16(c->auth_hash_algo); |
186 | err = ubifs_hmac_wkm(c, hmac: sup->hmac_wkm); |
187 | if (err) |
188 | goto out; |
189 | } else { |
190 | sup->hash_algo = cpu_to_le16(0xffff); |
191 | } |
192 | |
193 | sup->ch.node_type = UBIFS_SB_NODE; |
194 | sup->key_hash = UBIFS_KEY_HASH_R5; |
195 | sup->flags = cpu_to_le32(sup_flags); |
196 | sup->min_io_size = cpu_to_le32(c->min_io_size); |
197 | sup->leb_size = cpu_to_le32(c->leb_size); |
198 | sup->leb_cnt = cpu_to_le32(c->leb_cnt); |
199 | sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); |
200 | sup->max_bud_bytes = cpu_to_le64(tmp64); |
201 | sup->log_lebs = cpu_to_le32(log_lebs); |
202 | sup->lpt_lebs = cpu_to_le32(lpt_lebs); |
203 | sup->orph_lebs = cpu_to_le32(orph_lebs); |
204 | sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); |
205 | sup->fanout = cpu_to_le32(DEFAULT_FANOUT); |
206 | sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); |
207 | sup->fmt_version = cpu_to_le32(ubifs_default_version); |
208 | sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); |
209 | if (c->mount_opts.override_compr) |
210 | sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); |
211 | else |
212 | sup->default_compr = cpu_to_le16(get_default_compressor(c)); |
213 | |
214 | generate_random_uuid(uuid: sup->uuid); |
215 | |
216 | main_bytes = (long long)main_lebs * c->leb_size; |
217 | tmp64 = div_u64(dividend: main_bytes * DEFAULT_RP_PERCENT, divisor: 100); |
218 | if (tmp64 > DEFAULT_MAX_RP_SIZE) |
219 | tmp64 = DEFAULT_MAX_RP_SIZE; |
220 | sup->rp_size = cpu_to_le64(tmp64); |
221 | sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); |
222 | |
223 | dbg_gen("default superblock created at LEB 0:0" ); |
224 | |
225 | /* Create default master node */ |
226 | |
227 | mst->ch.node_type = UBIFS_MST_NODE; |
228 | mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); |
229 | mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); |
230 | mst->cmt_no = 0; |
231 | mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); |
232 | mst->root_offs = 0; |
233 | tmp = ubifs_idx_node_sz(c, child_cnt: 1); |
234 | mst->root_len = cpu_to_le32(tmp); |
235 | mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); |
236 | mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); |
237 | mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); |
238 | mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); |
239 | mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); |
240 | mst->lpt_offs = cpu_to_le32(c->lpt_offs); |
241 | mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); |
242 | mst->nhead_offs = cpu_to_le32(c->nhead_offs); |
243 | mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); |
244 | mst->ltab_offs = cpu_to_le32(c->ltab_offs); |
245 | mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); |
246 | mst->lsave_offs = cpu_to_le32(c->lsave_offs); |
247 | mst->lscan_lnum = cpu_to_le32(main_first); |
248 | mst->empty_lebs = cpu_to_le32(main_lebs - 2); |
249 | mst->idx_lebs = cpu_to_le32(1); |
250 | mst->leb_cnt = cpu_to_le32(c->leb_cnt); |
251 | ubifs_copy_hash(c, from: hash_lpt, to: mst->hash_lpt); |
252 | |
253 | /* Calculate lprops statistics */ |
254 | tmp64 = main_bytes; |
255 | tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); |
256 | tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); |
257 | mst->total_free = cpu_to_le64(tmp64); |
258 | |
259 | tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); |
260 | ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - |
261 | UBIFS_INO_NODE_SZ; |
262 | tmp64 += ino_waste; |
263 | tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); |
264 | mst->total_dirty = cpu_to_le64(tmp64); |
265 | |
266 | /* The indexing LEB does not contribute to dark space */ |
267 | tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); |
268 | mst->total_dark = cpu_to_le64(tmp64); |
269 | |
270 | mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); |
271 | |
272 | dbg_gen("default master node created at LEB %d:0" , UBIFS_MST_LNUM); |
273 | |
274 | /* Create the root indexing node */ |
275 | |
276 | c->key_fmt = UBIFS_SIMPLE_KEY_FMT; |
277 | c->key_hash = key_r5_hash; |
278 | |
279 | idx->ch.node_type = UBIFS_IDX_NODE; |
280 | idx->child_cnt = cpu_to_le16(1); |
281 | ino_key_init(c, key: &key, UBIFS_ROOT_INO); |
282 | br = ubifs_idx_branch(c, idx, bnum: 0); |
283 | key_write_idx(c, from: &key, to: &br->key); |
284 | br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); |
285 | br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); |
286 | |
287 | dbg_gen("default root indexing node created LEB %d:0" , |
288 | main_first + DEFAULT_IDX_LEB); |
289 | |
290 | /* Create default root inode */ |
291 | |
292 | ino_key_init_flash(c, k: &ino->key, UBIFS_ROOT_INO); |
293 | ino->ch.node_type = UBIFS_INO_NODE; |
294 | ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); |
295 | ino->nlink = cpu_to_le32(2); |
296 | |
297 | ktime_get_coarse_real_ts64(ts: &ts); |
298 | tmp_le64 = cpu_to_le64(ts.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 | dbg_gen("root inode created at LEB %d:0" , |
312 | main_first + DEFAULT_DATA_LEB); |
313 | |
314 | /* |
315 | * The first node in the log has to be the commit start node. This is |
316 | * always the case during normal file-system operation. Write a fake |
317 | * commit start node to the log. |
318 | */ |
319 | |
320 | cs->ch.node_type = UBIFS_CS_NODE; |
321 | |
322 | err = ubifs_write_node_hmac(c, buf: sup, UBIFS_SB_NODE_SZ, lnum: 0, offs: 0, |
323 | offsetof(struct ubifs_sb_node, hmac)); |
324 | if (err) |
325 | goto out; |
326 | |
327 | err = ubifs_write_node(c, node: ino, UBIFS_INO_NODE_SZ, |
328 | lnum: main_first + DEFAULT_DATA_LEB, offs: 0); |
329 | if (err) |
330 | goto out; |
331 | |
332 | ubifs_node_calc_hash(c, buf: ino, hash); |
333 | ubifs_copy_hash(c, from: hash, to: ubifs_branch_hash(c, br)); |
334 | |
335 | err = ubifs_write_node(c, node: idx, len: idx_node_size, lnum: main_first + DEFAULT_IDX_LEB, offs: 0); |
336 | if (err) |
337 | goto out; |
338 | |
339 | ubifs_node_calc_hash(c, buf: idx, hash); |
340 | ubifs_copy_hash(c, from: hash, to: mst->hash_root_idx); |
341 | |
342 | err = ubifs_write_node_hmac(c, buf: mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, offs: 0, |
343 | offsetof(struct ubifs_mst_node, hmac)); |
344 | if (err) |
345 | goto out; |
346 | |
347 | err = ubifs_write_node_hmac(c, buf: mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, |
348 | offs: 0, offsetof(struct ubifs_mst_node, hmac)); |
349 | if (err) |
350 | goto out; |
351 | |
352 | err = ubifs_write_node(c, node: cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, offs: 0); |
353 | if (err) |
354 | goto out; |
355 | |
356 | ubifs_msg(c, fmt: "default file-system created" ); |
357 | |
358 | err = 0; |
359 | out: |
360 | kfree(objp: sup); |
361 | kfree(objp: mst); |
362 | kfree(objp: idx); |
363 | kfree(objp: ino); |
364 | kfree(objp: cs); |
365 | |
366 | return err; |
367 | } |
368 | |
369 | /** |
370 | * validate_sb - validate superblock node. |
371 | * @c: UBIFS file-system description object |
372 | * @sup: superblock node |
373 | * |
374 | * This function validates superblock node @sup. Since most of data was read |
375 | * from the superblock and stored in @c, the function validates fields in @c |
376 | * instead. Returns zero in case of success and %-EINVAL in case of validation |
377 | * failure. |
378 | */ |
379 | static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) |
380 | { |
381 | long long max_bytes; |
382 | int err = 1, min_leb_cnt; |
383 | |
384 | if (!c->key_hash) { |
385 | err = 2; |
386 | goto failed; |
387 | } |
388 | |
389 | if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { |
390 | err = 3; |
391 | goto failed; |
392 | } |
393 | |
394 | if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { |
395 | ubifs_err(c, fmt: "min. I/O unit mismatch: %d in superblock, %d real" , |
396 | le32_to_cpu(sup->min_io_size), c->min_io_size); |
397 | goto failed; |
398 | } |
399 | |
400 | if (le32_to_cpu(sup->leb_size) != c->leb_size) { |
401 | ubifs_err(c, fmt: "LEB size mismatch: %d in superblock, %d real" , |
402 | le32_to_cpu(sup->leb_size), c->leb_size); |
403 | goto failed; |
404 | } |
405 | |
406 | if (c->log_lebs < UBIFS_MIN_LOG_LEBS || |
407 | c->lpt_lebs < UBIFS_MIN_LPT_LEBS || |
408 | c->orph_lebs < UBIFS_MIN_ORPH_LEBS || |
409 | c->main_lebs < UBIFS_MIN_MAIN_LEBS) { |
410 | err = 4; |
411 | goto failed; |
412 | } |
413 | |
414 | /* |
415 | * Calculate minimum allowed amount of main area LEBs. This is very |
416 | * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we |
417 | * have just read from the superblock. |
418 | */ |
419 | min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; |
420 | min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; |
421 | |
422 | if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { |
423 | ubifs_err(c, fmt: "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required" , |
424 | c->leb_cnt, c->vi.size, min_leb_cnt); |
425 | goto failed; |
426 | } |
427 | |
428 | if (c->max_leb_cnt < c->leb_cnt) { |
429 | ubifs_err(c, fmt: "max. LEB count %d less than LEB count %d" , |
430 | c->max_leb_cnt, c->leb_cnt); |
431 | goto failed; |
432 | } |
433 | |
434 | if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { |
435 | ubifs_err(c, fmt: "too few main LEBs count %d, must be at least %d" , |
436 | c->main_lebs, UBIFS_MIN_MAIN_LEBS); |
437 | goto failed; |
438 | } |
439 | |
440 | max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; |
441 | if (c->max_bud_bytes < max_bytes) { |
442 | ubifs_err(c, fmt: "too small journal (%lld bytes), must be at least %lld bytes" , |
443 | c->max_bud_bytes, max_bytes); |
444 | goto failed; |
445 | } |
446 | |
447 | max_bytes = (long long)c->leb_size * c->main_lebs; |
448 | if (c->max_bud_bytes > max_bytes) { |
449 | ubifs_err(c, fmt: "too large journal size (%lld bytes), only %lld bytes available in the main area" , |
450 | c->max_bud_bytes, max_bytes); |
451 | goto failed; |
452 | } |
453 | |
454 | if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || |
455 | c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { |
456 | err = 9; |
457 | goto failed; |
458 | } |
459 | |
460 | if (c->fanout < UBIFS_MIN_FANOUT || |
461 | ubifs_idx_node_sz(c, child_cnt: c->fanout) > c->leb_size) { |
462 | err = 10; |
463 | goto failed; |
464 | } |
465 | |
466 | if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && |
467 | c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - |
468 | c->log_lebs - c->lpt_lebs - c->orph_lebs)) { |
469 | err = 11; |
470 | goto failed; |
471 | } |
472 | |
473 | if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + |
474 | c->orph_lebs + c->main_lebs != c->leb_cnt) { |
475 | err = 12; |
476 | goto failed; |
477 | } |
478 | |
479 | if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { |
480 | err = 13; |
481 | goto failed; |
482 | } |
483 | |
484 | if (c->rp_size < 0 || max_bytes < c->rp_size) { |
485 | err = 14; |
486 | goto failed; |
487 | } |
488 | |
489 | if (le32_to_cpu(sup->time_gran) > 1000000000 || |
490 | le32_to_cpu(sup->time_gran) < 1) { |
491 | err = 15; |
492 | goto failed; |
493 | } |
494 | |
495 | if (!c->double_hash && c->fmt_version >= 5) { |
496 | err = 16; |
497 | goto failed; |
498 | } |
499 | |
500 | if (c->encrypted && c->fmt_version < 5) { |
501 | err = 17; |
502 | goto failed; |
503 | } |
504 | |
505 | return 0; |
506 | |
507 | failed: |
508 | ubifs_err(c, fmt: "bad superblock, error %d" , err); |
509 | ubifs_dump_node(c, node: sup, ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size)); |
510 | return -EINVAL; |
511 | } |
512 | |
513 | /** |
514 | * ubifs_read_sb_node - read superblock node. |
515 | * @c: UBIFS file-system description object |
516 | * |
517 | * This function returns a pointer to the superblock node or a negative error |
518 | * code. Note, the user of this function is responsible of kfree()'ing the |
519 | * returned superblock buffer. |
520 | */ |
521 | static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) |
522 | { |
523 | struct ubifs_sb_node *sup; |
524 | int err; |
525 | |
526 | sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); |
527 | if (!sup) |
528 | return ERR_PTR(error: -ENOMEM); |
529 | |
530 | err = ubifs_read_node(c, buf: sup, type: UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, |
531 | UBIFS_SB_LNUM, offs: 0); |
532 | if (err) { |
533 | kfree(objp: sup); |
534 | return ERR_PTR(error: err); |
535 | } |
536 | |
537 | return sup; |
538 | } |
539 | |
540 | static int authenticate_sb_node(struct ubifs_info *c, |
541 | const struct ubifs_sb_node *sup) |
542 | { |
543 | unsigned int sup_flags = le32_to_cpu(sup->flags); |
544 | u8 hmac_wkm[UBIFS_HMAC_ARR_SZ]; |
545 | int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION); |
546 | int hash_algo; |
547 | int err; |
548 | |
549 | if (c->authenticated && !authenticated) { |
550 | ubifs_err(c, fmt: "authenticated FS forced, but found FS without authentication" ); |
551 | return -EINVAL; |
552 | } |
553 | |
554 | if (!c->authenticated && authenticated) { |
555 | ubifs_err(c, fmt: "authenticated FS found, but no key given" ); |
556 | return -EINVAL; |
557 | } |
558 | |
559 | ubifs_msg(c, fmt: "Mounting in %sauthenticated mode" , |
560 | c->authenticated ? "" : "un" ); |
561 | |
562 | if (!c->authenticated) |
563 | return 0; |
564 | |
565 | if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) |
566 | return -EOPNOTSUPP; |
567 | |
568 | hash_algo = le16_to_cpu(sup->hash_algo); |
569 | if (hash_algo >= HASH_ALGO__LAST) { |
570 | ubifs_err(c, fmt: "superblock uses unknown hash algo %d" , |
571 | hash_algo); |
572 | return -EINVAL; |
573 | } |
574 | |
575 | if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) { |
576 | ubifs_err(c, fmt: "This filesystem uses %s for hashing," |
577 | " but %s is specified" , hash_algo_name[hash_algo], |
578 | c->auth_hash_name); |
579 | return -EINVAL; |
580 | } |
581 | |
582 | /* |
583 | * The super block node can either be authenticated by a HMAC or |
584 | * by a signature in a ubifs_sig_node directly following the |
585 | * super block node to support offline image creation. |
586 | */ |
587 | if (ubifs_hmac_zero(c, hmac: sup->hmac)) { |
588 | err = ubifs_sb_verify_signature(c, sup); |
589 | } else { |
590 | err = ubifs_hmac_wkm(c, hmac: hmac_wkm); |
591 | if (err) |
592 | return err; |
593 | if (ubifs_check_hmac(c, expected: hmac_wkm, got: sup->hmac_wkm)) { |
594 | ubifs_err(c, fmt: "provided key does not fit" ); |
595 | return -ENOKEY; |
596 | } |
597 | err = ubifs_node_verify_hmac(c, buf: sup, len: sizeof(*sup), |
598 | offsetof(struct ubifs_sb_node, |
599 | hmac)); |
600 | } |
601 | |
602 | if (err) |
603 | ubifs_err(c, fmt: "Failed to authenticate superblock: %d" , err); |
604 | |
605 | return err; |
606 | } |
607 | |
608 | /** |
609 | * ubifs_write_sb_node - write superblock node. |
610 | * @c: UBIFS file-system description object |
611 | * @sup: superblock node read with 'ubifs_read_sb_node()' |
612 | * |
613 | * This function returns %0 on success and a negative error code on failure. |
614 | */ |
615 | int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) |
616 | { |
617 | int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); |
618 | int err; |
619 | |
620 | err = ubifs_prepare_node_hmac(c, node: sup, UBIFS_SB_NODE_SZ, |
621 | offsetof(struct ubifs_sb_node, hmac), pad: 1); |
622 | if (err) |
623 | return err; |
624 | |
625 | return ubifs_leb_change(c, UBIFS_SB_LNUM, buf: sup, len); |
626 | } |
627 | |
628 | /** |
629 | * ubifs_read_superblock - read superblock. |
630 | * @c: UBIFS file-system description object |
631 | * |
632 | * This function finds, reads and checks the superblock. If an empty UBI volume |
633 | * is being mounted, this function creates default superblock. Returns zero in |
634 | * case of success, and a negative error code in case of failure. |
635 | */ |
636 | int ubifs_read_superblock(struct ubifs_info *c) |
637 | { |
638 | int err, sup_flags; |
639 | struct ubifs_sb_node *sup; |
640 | |
641 | if (c->empty) { |
642 | err = create_default_filesystem(c); |
643 | if (err) |
644 | return err; |
645 | } |
646 | |
647 | sup = ubifs_read_sb_node(c); |
648 | if (IS_ERR(ptr: sup)) |
649 | return PTR_ERR(ptr: sup); |
650 | |
651 | c->sup_node = sup; |
652 | |
653 | c->fmt_version = le32_to_cpu(sup->fmt_version); |
654 | c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); |
655 | |
656 | /* |
657 | * The software supports all previous versions but not future versions, |
658 | * due to the unavailability of time-travelling equipment. |
659 | */ |
660 | if (c->fmt_version > UBIFS_FORMAT_VERSION) { |
661 | ubifs_assert(c, !c->ro_media || c->ro_mount); |
662 | if (!c->ro_mount || |
663 | c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { |
664 | ubifs_err(c, fmt: "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d" , |
665 | c->fmt_version, c->ro_compat_version, |
666 | UBIFS_FORMAT_VERSION, |
667 | UBIFS_RO_COMPAT_VERSION); |
668 | if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { |
669 | ubifs_msg(c, fmt: "only R/O mounting is possible" ); |
670 | err = -EROFS; |
671 | } else |
672 | err = -EINVAL; |
673 | goto out; |
674 | } |
675 | |
676 | /* |
677 | * The FS is mounted R/O, and the media format is |
678 | * R/O-compatible with the UBIFS implementation, so we can |
679 | * mount. |
680 | */ |
681 | c->rw_incompat = 1; |
682 | } |
683 | |
684 | if (c->fmt_version < 3) { |
685 | ubifs_err(c, fmt: "on-flash format version %d is not supported" , |
686 | c->fmt_version); |
687 | err = -EINVAL; |
688 | goto out; |
689 | } |
690 | |
691 | switch (sup->key_hash) { |
692 | case UBIFS_KEY_HASH_R5: |
693 | c->key_hash = key_r5_hash; |
694 | c->key_hash_type = UBIFS_KEY_HASH_R5; |
695 | break; |
696 | |
697 | case UBIFS_KEY_HASH_TEST: |
698 | c->key_hash = key_test_hash; |
699 | c->key_hash_type = UBIFS_KEY_HASH_TEST; |
700 | break; |
701 | } |
702 | |
703 | c->key_fmt = sup->key_fmt; |
704 | |
705 | switch (c->key_fmt) { |
706 | case UBIFS_SIMPLE_KEY_FMT: |
707 | c->key_len = UBIFS_SK_LEN; |
708 | break; |
709 | default: |
710 | ubifs_err(c, fmt: "unsupported key format" ); |
711 | err = -EINVAL; |
712 | goto out; |
713 | } |
714 | |
715 | c->leb_cnt = le32_to_cpu(sup->leb_cnt); |
716 | c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); |
717 | c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); |
718 | c->log_lebs = le32_to_cpu(sup->log_lebs); |
719 | c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); |
720 | c->orph_lebs = le32_to_cpu(sup->orph_lebs); |
721 | c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; |
722 | c->fanout = le32_to_cpu(sup->fanout); |
723 | c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); |
724 | c->rp_size = le64_to_cpu(sup->rp_size); |
725 | c->rp_uid = make_kuid(from: &init_user_ns, le32_to_cpu(sup->rp_uid)); |
726 | c->rp_gid = make_kgid(from: &init_user_ns, le32_to_cpu(sup->rp_gid)); |
727 | sup_flags = le32_to_cpu(sup->flags); |
728 | if (!c->mount_opts.override_compr) |
729 | c->default_compr = le16_to_cpu(sup->default_compr); |
730 | |
731 | c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); |
732 | memcpy(&c->uuid, &sup->uuid, 16); |
733 | c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); |
734 | c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); |
735 | c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); |
736 | c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); |
737 | |
738 | err = authenticate_sb_node(c, sup); |
739 | if (err) |
740 | goto out; |
741 | |
742 | if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { |
743 | ubifs_err(c, fmt: "Unknown feature flags found: %#x" , |
744 | sup_flags & ~UBIFS_FLG_MASK); |
745 | err = -EINVAL; |
746 | goto out; |
747 | } |
748 | |
749 | if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) { |
750 | ubifs_err(c, fmt: "file system contains encrypted files but UBIFS" |
751 | " was built without crypto support." ); |
752 | err = -EINVAL; |
753 | goto out; |
754 | } |
755 | |
756 | /* Automatically increase file system size to the maximum size */ |
757 | if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { |
758 | int old_leb_cnt = c->leb_cnt; |
759 | |
760 | c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); |
761 | sup->leb_cnt = cpu_to_le32(c->leb_cnt); |
762 | |
763 | c->superblock_need_write = 1; |
764 | |
765 | dbg_mnt("Auto resizing from %d LEBs to %d LEBs" , |
766 | old_leb_cnt, c->leb_cnt); |
767 | } |
768 | |
769 | c->log_bytes = (long long)c->log_lebs * c->leb_size; |
770 | c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; |
771 | c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; |
772 | c->lpt_last = c->lpt_first + c->lpt_lebs - 1; |
773 | c->orph_first = c->lpt_last + 1; |
774 | c->orph_last = c->orph_first + c->orph_lebs - 1; |
775 | c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; |
776 | c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; |
777 | c->main_first = c->leb_cnt - c->main_lebs; |
778 | |
779 | err = validate_sb(c, sup); |
780 | out: |
781 | return err; |
782 | } |
783 | |
784 | /** |
785 | * fixup_leb - fixup/unmap an LEB containing free space. |
786 | * @c: UBIFS file-system description object |
787 | * @lnum: the LEB number to fix up |
788 | * @len: number of used bytes in LEB (starting at offset 0) |
789 | * |
790 | * This function reads the contents of the given LEB number @lnum, then fixes |
791 | * it up, so that empty min. I/O units in the end of LEB are actually erased on |
792 | * flash (rather than being just all-0xff real data). If the LEB is completely |
793 | * empty, it is simply unmapped. |
794 | */ |
795 | static int fixup_leb(struct ubifs_info *c, int lnum, int len) |
796 | { |
797 | int err; |
798 | |
799 | ubifs_assert(c, len >= 0); |
800 | ubifs_assert(c, len % c->min_io_size == 0); |
801 | ubifs_assert(c, len < c->leb_size); |
802 | |
803 | if (len == 0) { |
804 | dbg_mnt("unmap empty LEB %d" , lnum); |
805 | return ubifs_leb_unmap(c, lnum); |
806 | } |
807 | |
808 | dbg_mnt("fixup LEB %d, data len %d" , lnum, len); |
809 | err = ubifs_leb_read(c, lnum, buf: c->sbuf, offs: 0, len, even_ebadmsg: 1); |
810 | if (err) |
811 | return err; |
812 | |
813 | return ubifs_leb_change(c, lnum, buf: c->sbuf, len); |
814 | } |
815 | |
816 | /** |
817 | * fixup_free_space - find & remap all LEBs containing free space. |
818 | * @c: UBIFS file-system description object |
819 | * |
820 | * This function walks through all LEBs in the filesystem and fiexes up those |
821 | * containing free/empty space. |
822 | */ |
823 | static int fixup_free_space(struct ubifs_info *c) |
824 | { |
825 | int lnum, err = 0; |
826 | struct ubifs_lprops *lprops; |
827 | |
828 | ubifs_get_lprops(c); |
829 | |
830 | /* Fixup LEBs in the master area */ |
831 | for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { |
832 | err = fixup_leb(c, lnum, len: c->mst_offs + c->mst_node_alsz); |
833 | if (err) |
834 | goto out; |
835 | } |
836 | |
837 | /* Unmap unused log LEBs */ |
838 | lnum = ubifs_next_log_lnum(c, lnum: c->lhead_lnum); |
839 | while (lnum != c->ltail_lnum) { |
840 | err = fixup_leb(c, lnum, len: 0); |
841 | if (err) |
842 | goto out; |
843 | lnum = ubifs_next_log_lnum(c, lnum); |
844 | } |
845 | |
846 | /* |
847 | * Fixup the log head which contains the only a CS node at the |
848 | * beginning. |
849 | */ |
850 | err = fixup_leb(c, lnum: c->lhead_lnum, |
851 | ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); |
852 | if (err) |
853 | goto out; |
854 | |
855 | /* Fixup LEBs in the LPT area */ |
856 | for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { |
857 | int free = c->ltab[lnum - c->lpt_first].free; |
858 | |
859 | if (free > 0) { |
860 | err = fixup_leb(c, lnum, len: c->leb_size - free); |
861 | if (err) |
862 | goto out; |
863 | } |
864 | } |
865 | |
866 | /* Unmap LEBs in the orphans area */ |
867 | for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { |
868 | err = fixup_leb(c, lnum, len: 0); |
869 | if (err) |
870 | goto out; |
871 | } |
872 | |
873 | /* Fixup LEBs in the main area */ |
874 | for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { |
875 | lprops = ubifs_lpt_lookup(c, lnum); |
876 | if (IS_ERR(ptr: lprops)) { |
877 | err = PTR_ERR(ptr: lprops); |
878 | goto out; |
879 | } |
880 | |
881 | if (lprops->free > 0) { |
882 | err = fixup_leb(c, lnum, len: c->leb_size - lprops->free); |
883 | if (err) |
884 | goto out; |
885 | } |
886 | } |
887 | |
888 | out: |
889 | ubifs_release_lprops(c); |
890 | return err; |
891 | } |
892 | |
893 | /** |
894 | * ubifs_fixup_free_space - find & fix all LEBs with free space. |
895 | * @c: UBIFS file-system description object |
896 | * |
897 | * This function fixes up LEBs containing free space on first mount, if the |
898 | * appropriate flag was set when the FS was created. Each LEB with one or more |
899 | * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure |
900 | * the free space is actually erased. E.g., this is necessary for some NAND |
901 | * chips, since the free space may have been programmed like real "0xff" data |
902 | * (generating a non-0xff ECC), causing future writes to the not-really-erased |
903 | * NAND pages to behave badly. After the space is fixed up, the superblock flag |
904 | * is cleared, so that this is skipped for all future mounts. |
905 | */ |
906 | int ubifs_fixup_free_space(struct ubifs_info *c) |
907 | { |
908 | int err; |
909 | struct ubifs_sb_node *sup = c->sup_node; |
910 | |
911 | ubifs_assert(c, c->space_fixup); |
912 | ubifs_assert(c, !c->ro_mount); |
913 | |
914 | ubifs_msg(c, fmt: "start fixing up free space" ); |
915 | |
916 | err = fixup_free_space(c); |
917 | if (err) |
918 | return err; |
919 | |
920 | /* Free-space fixup is no longer required */ |
921 | c->space_fixup = 0; |
922 | sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); |
923 | |
924 | c->superblock_need_write = 1; |
925 | |
926 | ubifs_msg(c, fmt: "free space fixup complete" ); |
927 | return err; |
928 | } |
929 | |
930 | int ubifs_enable_encryption(struct ubifs_info *c) |
931 | { |
932 | int err; |
933 | struct ubifs_sb_node *sup = c->sup_node; |
934 | |
935 | if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) |
936 | return -EOPNOTSUPP; |
937 | |
938 | if (c->encrypted) |
939 | return 0; |
940 | |
941 | if (c->ro_mount || c->ro_media) |
942 | return -EROFS; |
943 | |
944 | if (c->fmt_version < 5) { |
945 | ubifs_err(c, fmt: "on-flash format version 5 is needed for encryption" ); |
946 | return -EINVAL; |
947 | } |
948 | |
949 | sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION); |
950 | |
951 | err = ubifs_write_sb_node(c, sup); |
952 | if (!err) |
953 | c->encrypted = 1; |
954 | |
955 | return err; |
956 | } |
957 | |