1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
6 #include <linux/slab.h>
7 #include <asm/unaligned.h>
8 #include <linux/buffer_head.h>
10 #include "exfat_raw.h"
13 static int exfat_mirror_bh(struct super_block *sb, sector_t sec,
14 struct buffer_head *bh)
16 struct buffer_head *c_bh;
17 struct exfat_sb_info *sbi = EXFAT_SB(sb);
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);
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);
37 static int __exfat_ent_get(struct super_block *sb, unsigned int loc,
38 unsigned int *content)
42 struct buffer_head *bh;
44 sec = FAT_ENT_OFFSET_SECTOR(sb, loc);
45 off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc);
47 bh = sb_bread(sb, sec);
51 *content = le32_to_cpu(*(__le32 *)(&bh->b_data[off]));
53 /* remap reserved clusters to simplify code */
54 if (*content > EXFAT_BAD_CLUSTER)
55 *content = EXFAT_EOF_CLUSTER;
61 int exfat_ent_set(struct super_block *sb, unsigned int loc,
67 struct buffer_head *bh;
69 sec = FAT_ENT_OFFSET_SECTOR(sb, loc);
70 off = FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc);
72 bh = sb_bread(sb, sec);
76 fat_entry = (__le32 *)&(bh->b_data[off]);
77 *fat_entry = cpu_to_le32(content);
78 exfat_update_bh(bh, sb->s_flags & SB_SYNCHRONOUS);
79 exfat_mirror_bh(sb, sec, bh);
84 static inline bool is_valid_cluster(struct exfat_sb_info *sbi,
87 if (clus < EXFAT_FIRST_CLUSTER || sbi->num_clusters <= clus)
92 int exfat_ent_get(struct super_block *sb, unsigned int loc,
93 unsigned int *content)
95 struct exfat_sb_info *sbi = EXFAT_SB(sb);
98 if (!is_valid_cluster(sbi, loc)) {
99 exfat_fs_error(sb, "invalid access to FAT (entry 0x%08x)",
104 err = __exfat_ent_get(sb, loc, content);
107 "failed to access to FAT (entry 0x%08x, err:%d)",
112 if (*content == EXFAT_FREE_CLUSTER) {
114 "invalid access to FAT free cluster (entry 0x%08x)",
119 if (*content == EXFAT_BAD_CLUSTER) {
121 "invalid access to FAT bad cluster (entry 0x%08x)",
126 if (*content != EXFAT_EOF_CLUSTER && !is_valid_cluster(sbi, *content)) {
128 "invalid access to FAT (entry 0x%08x) bogus content (0x%08x)",
136 int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
143 if (exfat_ent_set(sb, chain, chain + 1))
149 if (exfat_ent_set(sb, chain, EXFAT_EOF_CLUSTER))
154 int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain)
156 unsigned int num_clusters = 0;
158 struct super_block *sb = inode->i_sb;
159 struct exfat_sb_info *sbi = EXFAT_SB(sb);
160 int cur_cmap_i, next_cmap_i;
162 /* invalid cluster number */
163 if (p_chain->dir == EXFAT_FREE_CLUSTER ||
164 p_chain->dir == EXFAT_EOF_CLUSTER ||
165 p_chain->dir < EXFAT_FIRST_CLUSTER)
168 /* no cluster to truncate */
169 if (p_chain->size == 0)
172 /* check cluster validation */
173 if (!is_valid_cluster(sbi, p_chain->dir)) {
174 exfat_err(sb, "invalid start cluster (%u)", p_chain->dir);
180 cur_cmap_i = next_cmap_i =
181 BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(clu));
183 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
184 unsigned int last_cluster = p_chain->dir + p_chain->size - 1;
188 if (clu < last_cluster)
190 BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(clu+1));
192 /* flush bitmap only if index would be changed or for last cluster */
193 if (clu == last_cluster || cur_cmap_i != next_cmap_i) {
195 cur_cmap_i = next_cmap_i;
198 exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)));
201 } while (num_clusters < p_chain->size);
205 unsigned int n_clu = clu;
206 int err = exfat_get_next_cluster(sb, &n_clu);
208 if (err || n_clu == EXFAT_EOF_CLUSTER)
212 BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(n_clu));
214 if (cur_cmap_i != next_cmap_i) {
216 cur_cmap_i = next_cmap_i;
219 exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)));
225 } while (clu != EXFAT_EOF_CLUSTER);
229 sbi->used_clusters -= num_clusters;
233 int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
234 unsigned int *ret_clu)
236 unsigned int clu, next;
237 unsigned int count = 0;
240 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
241 *ret_clu = next + p_chain->size - 1;
248 if (exfat_ent_get(sb, clu, &next))
250 } while (next != EXFAT_EOF_CLUSTER);
252 if (p_chain->size != count) {
254 "bogus directory size (clus : ondisk(%d) != counted(%d))",
255 p_chain->size, count);
263 int exfat_zeroed_cluster(struct inode *dir, unsigned int clu)
265 struct super_block *sb = dir->i_sb;
266 struct exfat_sb_info *sbi = EXFAT_SB(sb);
267 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
268 int nr_bhs = MAX_BUF_PER_PAGE;
269 sector_t blknr, last_blknr;
272 blknr = exfat_cluster_to_sector(sbi, clu);
273 last_blknr = blknr + sbi->sect_per_clus;
275 if (last_blknr > sbi->num_sectors && sbi->num_sectors > 0) {
276 exfat_fs_error_ratelimit(sb,
277 "%s: out of range(sect:%llu len:%u)",
278 __func__, (unsigned long long)blknr,
283 /* Zeroing the unused blocks on this cluster */
284 while (blknr < last_blknr) {
285 for (n = 0; n < nr_bhs && blknr < last_blknr; n++, blknr++) {
286 bhs[n] = sb_getblk(sb, blknr);
291 memset(bhs[n]->b_data, 0, sb->s_blocksize);
294 err = exfat_update_bhs(bhs, n, IS_DIRSYNC(dir));
298 for (i = 0; i < n; i++)
304 exfat_err(sb, "failed zeroed sect %llu\n", (unsigned long long)blknr);
305 for (i = 0; i < n; i++)
310 int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
311 struct exfat_chain *p_chain)
314 unsigned int num_clusters = 0, total_cnt;
315 unsigned int hint_clu, new_clu, last_clu = EXFAT_EOF_CLUSTER;
316 struct super_block *sb = inode->i_sb;
317 struct exfat_sb_info *sbi = EXFAT_SB(sb);
319 total_cnt = EXFAT_DATA_CLUSTER_COUNT(sbi);
321 if (unlikely(total_cnt < sbi->used_clusters)) {
322 exfat_fs_error_ratelimit(sb,
323 "%s: invalid used clusters(t:%u,u:%u)\n",
324 __func__, total_cnt, sbi->used_clusters);
328 if (num_alloc > total_cnt - sbi->used_clusters)
331 hint_clu = p_chain->dir;
332 /* find new cluster */
333 if (hint_clu == EXFAT_EOF_CLUSTER) {
334 if (sbi->clu_srch_ptr < EXFAT_FIRST_CLUSTER) {
335 exfat_err(sb, "sbi->clu_srch_ptr is invalid (%u)\n",
337 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
340 hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr);
341 if (hint_clu == EXFAT_EOF_CLUSTER)
345 /* check cluster validation */
346 if (!is_valid_cluster(sbi, hint_clu)) {
347 exfat_err(sb, "hint_cluster is invalid (%u)",
349 hint_clu = EXFAT_FIRST_CLUSTER;
350 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
351 if (exfat_chain_cont_cluster(sb, p_chain->dir,
354 p_chain->flags = ALLOC_FAT_CHAIN;
358 p_chain->dir = EXFAT_EOF_CLUSTER;
360 while ((new_clu = exfat_find_free_bitmap(sb, hint_clu)) !=
362 if (new_clu != hint_clu &&
363 p_chain->flags == ALLOC_NO_FAT_CHAIN) {
364 if (exfat_chain_cont_cluster(sb, p_chain->dir,
369 p_chain->flags = ALLOC_FAT_CHAIN;
372 /* update allocation bitmap */
373 if (exfat_set_bitmap(inode, new_clu)) {
380 /* update FAT table */
381 if (p_chain->flags == ALLOC_FAT_CHAIN) {
382 if (exfat_ent_set(sb, new_clu, EXFAT_EOF_CLUSTER)) {
388 if (p_chain->dir == EXFAT_EOF_CLUSTER) {
389 p_chain->dir = new_clu;
390 } else if (p_chain->flags == ALLOC_FAT_CHAIN) {
391 if (exfat_ent_set(sb, last_clu, new_clu)) {
398 if (--num_alloc == 0) {
399 sbi->clu_srch_ptr = hint_clu;
400 sbi->used_clusters += num_clusters;
402 p_chain->size += num_clusters;
406 hint_clu = new_clu + 1;
407 if (hint_clu >= sbi->num_clusters) {
408 hint_clu = EXFAT_FIRST_CLUSTER;
410 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
411 if (exfat_chain_cont_cluster(sb, p_chain->dir,
416 p_chain->flags = ALLOC_FAT_CHAIN;
422 exfat_free_cluster(inode, p_chain);
426 int exfat_count_num_clusters(struct super_block *sb,
427 struct exfat_chain *p_chain, unsigned int *ret_count)
429 unsigned int i, count;
431 struct exfat_sb_info *sbi = EXFAT_SB(sb);
433 if (!p_chain->dir || p_chain->dir == EXFAT_EOF_CLUSTER) {
438 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
439 *ret_count = p_chain->size;
445 for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters; i++) {
447 if (exfat_ent_get(sb, clu, &clu))
449 if (clu == EXFAT_EOF_CLUSTER)