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31023864 NJ |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. | |
4 | */ | |
5 | ||
6 | #include <linux/slab.h> | |
7 | #include <asm/unaligned.h> | |
8 | #include <linux/buffer_head.h> | |
9 | ||
10 | #include "exfat_raw.h" | |
11 | #include "exfat_fs.h" | |
12 | ||
13 | static int exfat_mirror_bh(struct super_block *sb, sector_t sec, | |
14 | struct buffer_head *bh) | |
15 | { | |
16 | struct buffer_head *c_bh; | |
17 | struct exfat_sb_info *sbi = EXFAT_SB(sb); | |
18 | sector_t sec2; | |
19 | int err = 0; | |
20 | ||
21 | if (sbi->FAT2_start_sector != sbi->FAT1_start_sector) { | |
22 | sec2 = sec - sbi->FAT1_start_sector + sbi->FAT2_start_sector; | |
23 | c_bh = sb_getblk(sb, sec2); | |
24 | if (!c_bh) | |
25 | return -ENOMEM; | |
26 | memcpy(c_bh->b_data, bh->b_data, sb->s_blocksize); | |
27 | set_buffer_uptodate(c_bh); | |
28 | mark_buffer_dirty(c_bh); | |
29 | if (sb->s_flags & SB_SYNCHRONOUS) | |
30 | err = sync_dirty_buffer(c_bh); | |
31 | brelse(c_bh); | |
32 | } | |
33 | ||
34 | return err; | |
35 | } | |
36 | ||
37 | static int __exfat_ent_get(struct super_block *sb, unsigned int loc, | |
38 | unsigned int *content) | |
39 | { | |
40 | unsigned int off; | |
41 | sector_t sec; | |
42 | struct buffer_head *bh; | |
43 | ||
44 | sec = FAT_ENT_OFFSET_SECTOR(sb, loc); | |
45 | off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc); | |
46 | ||
47 | bh = sb_bread(sb, sec); | |
48 | if (!bh) | |
49 | return -EIO; | |
50 | ||
51 | *content = le32_to_cpu(*(__le32 *)(&bh->b_data[off])); | |
52 | ||
53 | /* remap reserved clusters to simplify code */ | |
54 | if (*content > EXFAT_BAD_CLUSTER) | |
55 | *content = EXFAT_EOF_CLUSTER; | |
56 | ||
57 | brelse(bh); | |
58 | return 0; | |
59 | } | |
60 | ||
61 | int exfat_ent_set(struct super_block *sb, unsigned int loc, | |
62 | unsigned int content) | |
63 | { | |
64 | unsigned int off; | |
65 | sector_t sec; | |
66 | __le32 *fat_entry; | |
67 | struct buffer_head *bh; | |
68 | ||
69 | sec = FAT_ENT_OFFSET_SECTOR(sb, loc); | |
70 | off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc); | |
71 | ||
72 | bh = sb_bread(sb, sec); | |
73 | if (!bh) | |
74 | return -EIO; | |
75 | ||
76 | fat_entry = (__le32 *)&(bh->b_data[off]); | |
77 | *fat_entry = cpu_to_le32(content); | |
78 | exfat_update_bh(sb, bh, sb->s_flags & SB_SYNCHRONOUS); | |
79 | exfat_mirror_bh(sb, sec, bh); | |
80 | brelse(bh); | |
81 | return 0; | |
82 | } | |
83 | ||
84 | static inline bool is_valid_cluster(struct exfat_sb_info *sbi, | |
85 | unsigned int clus) | |
86 | { | |
87 | if (clus < EXFAT_FIRST_CLUSTER || sbi->num_clusters <= clus) | |
88 | return false; | |
89 | return true; | |
90 | } | |
91 | ||
92 | int exfat_ent_get(struct super_block *sb, unsigned int loc, | |
93 | unsigned int *content) | |
94 | { | |
95 | struct exfat_sb_info *sbi = EXFAT_SB(sb); | |
96 | int err; | |
97 | ||
98 | if (!is_valid_cluster(sbi, loc)) { | |
99 | exfat_fs_error(sb, "invalid access to FAT (entry 0x%08x)", | |
100 | loc); | |
101 | return -EIO; | |
102 | } | |
103 | ||
104 | err = __exfat_ent_get(sb, loc, content); | |
105 | if (err) { | |
106 | exfat_fs_error(sb, | |
107 | "failed to access to FAT (entry 0x%08x, err:%d)", | |
108 | loc, err); | |
109 | return err; | |
110 | } | |
111 | ||
112 | if (*content == EXFAT_FREE_CLUSTER) { | |
113 | exfat_fs_error(sb, | |
114 | "invalid access to FAT free cluster (entry 0x%08x)", | |
115 | loc); | |
116 | return -EIO; | |
117 | } | |
118 | ||
119 | if (*content == EXFAT_BAD_CLUSTER) { | |
120 | exfat_fs_error(sb, | |
121 | "invalid access to FAT bad cluster (entry 0x%08x)", | |
122 | loc); | |
123 | return -EIO; | |
124 | } | |
125 | ||
126 | if (*content != EXFAT_EOF_CLUSTER && !is_valid_cluster(sbi, *content)) { | |
127 | exfat_fs_error(sb, | |
128 | "invalid access to FAT (entry 0x%08x) bogus content (0x%08x)", | |
129 | loc, *content); | |
130 | return -EIO; | |
131 | } | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain, | |
137 | unsigned int len) | |
138 | { | |
139 | if (!len) | |
140 | return 0; | |
141 | ||
142 | while (len > 1) { | |
143 | if (exfat_ent_set(sb, chain, chain + 1)) | |
144 | return -EIO; | |
145 | chain++; | |
146 | len--; | |
147 | } | |
148 | ||
149 | if (exfat_ent_set(sb, chain, EXFAT_EOF_CLUSTER)) | |
150 | return -EIO; | |
151 | return 0; | |
152 | } | |
153 | ||
154 | int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain) | |
155 | { | |
156 | unsigned int num_clusters = 0; | |
157 | unsigned int clu; | |
158 | struct super_block *sb = inode->i_sb; | |
159 | struct exfat_sb_info *sbi = EXFAT_SB(sb); | |
160 | ||
161 | /* invalid cluster number */ | |
162 | if (p_chain->dir == EXFAT_FREE_CLUSTER || | |
163 | p_chain->dir == EXFAT_EOF_CLUSTER || | |
164 | p_chain->dir < EXFAT_FIRST_CLUSTER) | |
165 | return 0; | |
166 | ||
167 | /* no cluster to truncate */ | |
168 | if (p_chain->size == 0) | |
169 | return 0; | |
170 | ||
171 | /* check cluster validation */ | |
172 | if (p_chain->dir < 2 && p_chain->dir >= sbi->num_clusters) { | |
173 | exfat_msg(sb, KERN_ERR, "invalid start cluster (%u)", | |
174 | p_chain->dir); | |
175 | return -EIO; | |
176 | } | |
177 | ||
178 | set_bit(EXFAT_SB_DIRTY, &sbi->s_state); | |
179 | clu = p_chain->dir; | |
180 | ||
181 | if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { | |
182 | do { | |
183 | exfat_clear_bitmap(inode, clu); | |
184 | clu++; | |
185 | ||
186 | num_clusters++; | |
187 | } while (num_clusters < p_chain->size); | |
188 | } else { | |
189 | do { | |
190 | exfat_clear_bitmap(inode, clu); | |
191 | ||
192 | if (exfat_get_next_cluster(sb, &clu)) | |
193 | goto dec_used_clus; | |
194 | ||
195 | num_clusters++; | |
196 | } while (clu != EXFAT_EOF_CLUSTER); | |
197 | } | |
198 | ||
199 | dec_used_clus: | |
200 | sbi->used_clusters -= num_clusters; | |
201 | return 0; | |
202 | } | |
203 | ||
204 | int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain, | |
205 | unsigned int *ret_clu) | |
206 | { | |
207 | unsigned int clu, next; | |
208 | unsigned int count = 0; | |
209 | ||
210 | next = p_chain->dir; | |
211 | if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { | |
212 | *ret_clu = next + p_chain->size - 1; | |
213 | return 0; | |
214 | } | |
215 | ||
216 | do { | |
217 | count++; | |
218 | clu = next; | |
219 | if (exfat_ent_get(sb, clu, &next)) | |
220 | return -EIO; | |
221 | } while (next != EXFAT_EOF_CLUSTER); | |
222 | ||
223 | if (p_chain->size != count) { | |
224 | exfat_fs_error(sb, | |
225 | "bogus directory size (clus : ondisk(%d) != counted(%d))", | |
226 | p_chain->size, count); | |
227 | return -EIO; | |
228 | } | |
229 | ||
230 | *ret_clu = clu; | |
231 | return 0; | |
232 | } | |
233 | ||
234 | static inline int exfat_sync_bhs(struct buffer_head **bhs, int nr_bhs) | |
235 | { | |
236 | int i, err = 0; | |
237 | ||
238 | for (i = 0; i < nr_bhs; i++) | |
239 | write_dirty_buffer(bhs[i], 0); | |
240 | ||
241 | for (i = 0; i < nr_bhs; i++) { | |
242 | wait_on_buffer(bhs[i]); | |
243 | if (!err && !buffer_uptodate(bhs[i])) | |
244 | err = -EIO; | |
245 | } | |
246 | return err; | |
247 | } | |
248 | ||
249 | int exfat_zeroed_cluster(struct inode *dir, unsigned int clu) | |
250 | { | |
251 | struct super_block *sb = dir->i_sb; | |
252 | struct exfat_sb_info *sbi = EXFAT_SB(sb); | |
253 | struct buffer_head *bhs[MAX_BUF_PER_PAGE]; | |
254 | int nr_bhs = MAX_BUF_PER_PAGE; | |
255 | sector_t blknr, last_blknr; | |
256 | int err, i, n; | |
257 | ||
258 | blknr = exfat_cluster_to_sector(sbi, clu); | |
259 | last_blknr = blknr + sbi->sect_per_clus; | |
260 | ||
261 | if (last_blknr > sbi->num_sectors && sbi->num_sectors > 0) { | |
262 | exfat_fs_error_ratelimit(sb, | |
263 | "%s: out of range(sect:%llu len:%u)", | |
264 | __func__, (unsigned long long)blknr, | |
265 | sbi->sect_per_clus); | |
266 | return -EIO; | |
267 | } | |
268 | ||
269 | /* Zeroing the unused blocks on this cluster */ | |
270 | n = 0; | |
271 | while (blknr < last_blknr) { | |
272 | bhs[n] = sb_getblk(sb, blknr); | |
273 | if (!bhs[n]) { | |
274 | err = -ENOMEM; | |
275 | goto release_bhs; | |
276 | } | |
277 | memset(bhs[n]->b_data, 0, sb->s_blocksize); | |
278 | exfat_update_bh(sb, bhs[n], 0); | |
279 | ||
280 | n++; | |
281 | blknr++; | |
282 | ||
283 | if (n == nr_bhs) { | |
284 | if (IS_DIRSYNC(dir)) { | |
285 | err = exfat_sync_bhs(bhs, n); | |
286 | if (err) | |
287 | goto release_bhs; | |
288 | } | |
289 | ||
290 | for (i = 0; i < n; i++) | |
291 | brelse(bhs[i]); | |
292 | n = 0; | |
293 | } | |
294 | } | |
295 | ||
296 | if (IS_DIRSYNC(dir)) { | |
297 | err = exfat_sync_bhs(bhs, n); | |
298 | if (err) | |
299 | goto release_bhs; | |
300 | } | |
301 | ||
302 | for (i = 0; i < n; i++) | |
303 | brelse(bhs[i]); | |
304 | ||
305 | return 0; | |
306 | ||
307 | release_bhs: | |
308 | exfat_msg(sb, KERN_ERR, "failed zeroed sect %llu\n", | |
309 | (unsigned long long)blknr); | |
310 | for (i = 0; i < n; i++) | |
311 | bforget(bhs[i]); | |
312 | return err; | |
313 | } | |
314 | ||
315 | int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc, | |
316 | struct exfat_chain *p_chain) | |
317 | { | |
318 | int ret = -ENOSPC; | |
319 | unsigned int num_clusters = 0, total_cnt; | |
320 | unsigned int hint_clu, new_clu, last_clu = EXFAT_EOF_CLUSTER; | |
321 | struct super_block *sb = inode->i_sb; | |
322 | struct exfat_sb_info *sbi = EXFAT_SB(sb); | |
323 | ||
324 | total_cnt = EXFAT_DATA_CLUSTER_COUNT(sbi); | |
325 | ||
326 | if (unlikely(total_cnt < sbi->used_clusters)) { | |
327 | exfat_fs_error_ratelimit(sb, | |
328 | "%s: invalid used clusters(t:%u,u:%u)\n", | |
329 | __func__, total_cnt, sbi->used_clusters); | |
330 | return -EIO; | |
331 | } | |
332 | ||
333 | if (num_alloc > total_cnt - sbi->used_clusters) | |
334 | return -ENOSPC; | |
335 | ||
336 | hint_clu = p_chain->dir; | |
337 | /* find new cluster */ | |
338 | if (hint_clu == EXFAT_EOF_CLUSTER) { | |
339 | if (sbi->clu_srch_ptr < EXFAT_FIRST_CLUSTER) { | |
340 | exfat_msg(sb, KERN_ERR, | |
341 | "sbi->clu_srch_ptr is invalid (%u)\n", | |
342 | sbi->clu_srch_ptr); | |
343 | sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER; | |
344 | } | |
345 | ||
346 | hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr); | |
347 | if (hint_clu == EXFAT_EOF_CLUSTER) | |
348 | return -ENOSPC; | |
349 | } | |
350 | ||
351 | /* check cluster validation */ | |
352 | if (hint_clu < EXFAT_FIRST_CLUSTER && hint_clu >= sbi->num_clusters) { | |
353 | exfat_msg(sb, KERN_ERR, "hint_cluster is invalid (%u)\n", | |
354 | hint_clu); | |
355 | hint_clu = EXFAT_FIRST_CLUSTER; | |
356 | if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { | |
357 | if (exfat_chain_cont_cluster(sb, p_chain->dir, | |
358 | num_clusters)) | |
359 | return -EIO; | |
360 | p_chain->flags = ALLOC_FAT_CHAIN; | |
361 | } | |
362 | } | |
363 | ||
364 | set_bit(EXFAT_SB_DIRTY, &sbi->s_state); | |
365 | ||
366 | p_chain->dir = EXFAT_EOF_CLUSTER; | |
367 | ||
368 | while ((new_clu = exfat_find_free_bitmap(sb, hint_clu)) != | |
369 | EXFAT_EOF_CLUSTER) { | |
370 | if (new_clu != hint_clu && | |
371 | p_chain->flags == ALLOC_NO_FAT_CHAIN) { | |
372 | if (exfat_chain_cont_cluster(sb, p_chain->dir, | |
373 | num_clusters)) { | |
374 | ret = -EIO; | |
375 | goto free_cluster; | |
376 | } | |
377 | p_chain->flags = ALLOC_FAT_CHAIN; | |
378 | } | |
379 | ||
380 | /* update allocation bitmap */ | |
381 | if (exfat_set_bitmap(inode, new_clu)) { | |
382 | ret = -EIO; | |
383 | goto free_cluster; | |
384 | } | |
385 | ||
386 | num_clusters++; | |
387 | ||
388 | /* update FAT table */ | |
389 | if (p_chain->flags == ALLOC_FAT_CHAIN) { | |
390 | if (exfat_ent_set(sb, new_clu, EXFAT_EOF_CLUSTER)) { | |
391 | ret = -EIO; | |
392 | goto free_cluster; | |
393 | } | |
394 | } | |
395 | ||
396 | if (p_chain->dir == EXFAT_EOF_CLUSTER) { | |
397 | p_chain->dir = new_clu; | |
398 | } else if (p_chain->flags == ALLOC_FAT_CHAIN) { | |
399 | if (exfat_ent_set(sb, last_clu, new_clu)) { | |
400 | ret = -EIO; | |
401 | goto free_cluster; | |
402 | } | |
403 | } | |
404 | last_clu = new_clu; | |
405 | ||
406 | if (--num_alloc == 0) { | |
407 | sbi->clu_srch_ptr = hint_clu; | |
408 | sbi->used_clusters += num_clusters; | |
409 | ||
410 | p_chain->size += num_clusters; | |
411 | return 0; | |
412 | } | |
413 | ||
414 | hint_clu = new_clu + 1; | |
415 | if (hint_clu >= sbi->num_clusters) { | |
416 | hint_clu = EXFAT_FIRST_CLUSTER; | |
417 | ||
418 | if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { | |
419 | if (exfat_chain_cont_cluster(sb, p_chain->dir, | |
420 | num_clusters)) { | |
421 | ret = -EIO; | |
422 | goto free_cluster; | |
423 | } | |
424 | p_chain->flags = ALLOC_FAT_CHAIN; | |
425 | } | |
426 | } | |
427 | } | |
428 | free_cluster: | |
429 | if (num_clusters) | |
430 | exfat_free_cluster(inode, p_chain); | |
431 | return ret; | |
432 | } | |
433 | ||
434 | int exfat_count_num_clusters(struct super_block *sb, | |
435 | struct exfat_chain *p_chain, unsigned int *ret_count) | |
436 | { | |
437 | unsigned int i, count; | |
438 | unsigned int clu; | |
439 | struct exfat_sb_info *sbi = EXFAT_SB(sb); | |
440 | ||
441 | if (!p_chain->dir || p_chain->dir == EXFAT_EOF_CLUSTER) { | |
442 | *ret_count = 0; | |
443 | return 0; | |
444 | } | |
445 | ||
446 | if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { | |
447 | *ret_count = p_chain->size; | |
448 | return 0; | |
449 | } | |
450 | ||
451 | clu = p_chain->dir; | |
452 | count = 0; | |
453 | for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters; i++) { | |
454 | count++; | |
455 | if (exfat_ent_get(sb, clu, &clu)) | |
456 | return -EIO; | |
457 | if (clu == EXFAT_EOF_CLUSTER) | |
458 | break; | |
459 | } | |
460 | ||
461 | *ret_count = count; | |
462 | return 0; | |
463 | } |