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(sb, 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);
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)
167 /* no cluster to truncate */
168 if (p_chain->size == 0)
171 /* check cluster validation */
172 if (!is_valid_cluster(sbi, p_chain->dir)) {
173 exfat_err(sb, "invalid start cluster (%u)", p_chain->dir);
177 set_bit(EXFAT_SB_DIRTY, &sbi->s_state);
180 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
182 exfat_clear_bitmap(inode, clu);
186 } while (num_clusters < p_chain->size);
189 exfat_clear_bitmap(inode, clu);
191 if (exfat_get_next_cluster(sb, &clu))
195 } while (clu != EXFAT_EOF_CLUSTER);
199 sbi->used_clusters -= num_clusters;
203 int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
204 unsigned int *ret_clu)
206 unsigned int clu, next;
207 unsigned int count = 0;
210 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
211 *ret_clu = next + p_chain->size - 1;
218 if (exfat_ent_get(sb, clu, &next))
220 } while (next != EXFAT_EOF_CLUSTER);
222 if (p_chain->size != count) {
224 "bogus directory size (clus : ondisk(%d) != counted(%d))",
225 p_chain->size, count);
233 static inline int exfat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
237 for (i = 0; i < nr_bhs; i++)
238 write_dirty_buffer(bhs[i], 0);
240 for (i = 0; i < nr_bhs; i++) {
241 wait_on_buffer(bhs[i]);
242 if (!err && !buffer_uptodate(bhs[i]))
248 int exfat_zeroed_cluster(struct inode *dir, unsigned int clu)
250 struct super_block *sb = dir->i_sb;
251 struct exfat_sb_info *sbi = EXFAT_SB(sb);
252 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
253 int nr_bhs = MAX_BUF_PER_PAGE;
254 sector_t blknr, last_blknr;
257 blknr = exfat_cluster_to_sector(sbi, clu);
258 last_blknr = blknr + sbi->sect_per_clus;
260 if (last_blknr > sbi->num_sectors && sbi->num_sectors > 0) {
261 exfat_fs_error_ratelimit(sb,
262 "%s: out of range(sect:%llu len:%u)",
263 __func__, (unsigned long long)blknr,
268 /* Zeroing the unused blocks on this cluster */
270 while (blknr < last_blknr) {
271 bhs[n] = sb_getblk(sb, blknr);
276 memset(bhs[n]->b_data, 0, sb->s_blocksize);
277 exfat_update_bh(sb, bhs[n], 0);
283 if (IS_DIRSYNC(dir)) {
284 err = exfat_sync_bhs(bhs, n);
289 for (i = 0; i < n; i++)
295 if (IS_DIRSYNC(dir)) {
296 err = exfat_sync_bhs(bhs, n);
301 for (i = 0; i < n; i++)
307 exfat_err(sb, "failed zeroed sect %llu\n", (unsigned long long)blknr);
308 for (i = 0; i < n; i++)
313 int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
314 struct exfat_chain *p_chain)
317 unsigned int num_clusters = 0, total_cnt;
318 unsigned int hint_clu, new_clu, last_clu = EXFAT_EOF_CLUSTER;
319 struct super_block *sb = inode->i_sb;
320 struct exfat_sb_info *sbi = EXFAT_SB(sb);
322 total_cnt = EXFAT_DATA_CLUSTER_COUNT(sbi);
324 if (unlikely(total_cnt < sbi->used_clusters)) {
325 exfat_fs_error_ratelimit(sb,
326 "%s: invalid used clusters(t:%u,u:%u)\n",
327 __func__, total_cnt, sbi->used_clusters);
331 if (num_alloc > total_cnt - sbi->used_clusters)
334 hint_clu = p_chain->dir;
335 /* find new cluster */
336 if (hint_clu == EXFAT_EOF_CLUSTER) {
337 if (sbi->clu_srch_ptr < EXFAT_FIRST_CLUSTER) {
338 exfat_err(sb, "sbi->clu_srch_ptr is invalid (%u)\n",
340 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
343 hint_clu = exfat_find_free_bitmap(sb, sbi->clu_srch_ptr);
344 if (hint_clu == EXFAT_EOF_CLUSTER)
348 /* check cluster validation */
349 if (!is_valid_cluster(sbi, hint_clu)) {
350 exfat_err(sb, "hint_cluster is invalid (%u)",
352 hint_clu = EXFAT_FIRST_CLUSTER;
353 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
354 if (exfat_chain_cont_cluster(sb, p_chain->dir,
357 p_chain->flags = ALLOC_FAT_CHAIN;
361 set_bit(EXFAT_SB_DIRTY, &sbi->s_state);
363 p_chain->dir = EXFAT_EOF_CLUSTER;
365 while ((new_clu = exfat_find_free_bitmap(sb, hint_clu)) !=
367 if (new_clu != hint_clu &&
368 p_chain->flags == ALLOC_NO_FAT_CHAIN) {
369 if (exfat_chain_cont_cluster(sb, p_chain->dir,
374 p_chain->flags = ALLOC_FAT_CHAIN;
377 /* update allocation bitmap */
378 if (exfat_set_bitmap(inode, new_clu)) {
385 /* update FAT table */
386 if (p_chain->flags == ALLOC_FAT_CHAIN) {
387 if (exfat_ent_set(sb, new_clu, EXFAT_EOF_CLUSTER)) {
393 if (p_chain->dir == EXFAT_EOF_CLUSTER) {
394 p_chain->dir = new_clu;
395 } else if (p_chain->flags == ALLOC_FAT_CHAIN) {
396 if (exfat_ent_set(sb, last_clu, new_clu)) {
403 if (--num_alloc == 0) {
404 sbi->clu_srch_ptr = hint_clu;
405 sbi->used_clusters += num_clusters;
407 p_chain->size += num_clusters;
411 hint_clu = new_clu + 1;
412 if (hint_clu >= sbi->num_clusters) {
413 hint_clu = EXFAT_FIRST_CLUSTER;
415 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
416 if (exfat_chain_cont_cluster(sb, p_chain->dir,
421 p_chain->flags = ALLOC_FAT_CHAIN;
427 exfat_free_cluster(inode, p_chain);
431 int exfat_count_num_clusters(struct super_block *sb,
432 struct exfat_chain *p_chain, unsigned int *ret_count)
434 unsigned int i, count;
436 struct exfat_sb_info *sbi = EXFAT_SB(sb);
438 if (!p_chain->dir || p_chain->dir == EXFAT_EOF_CLUSTER) {
443 if (p_chain->flags == ALLOC_NO_FAT_CHAIN) {
444 *ret_count = p_chain->size;
450 for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters; i++) {
452 if (exfat_ent_get(sb, clu, &clu))
454 if (clu == EXFAT_EOF_CLUSTER)