exfat: use exfat_cluster_walk helper

Replace the custom exfat_walk_fat_chain() function and open-coded
FAT chain walking logic with the exfat_cluster_walk() helper across
exfat_find_location, __exfat_get_dentry_set, and exfat_map_cluster.

Suggested-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

diff --git a/fs/exfat/dir.c b/fs/exfat/dir.c
index 7619410d668e8209ebdcac2fa0c7420042c6813b..ca5827046a1f90bbd126a1097c681d2326eca3aa 100644 (file)
--- a/fs/exfat/dir.c
+++ b/fs/exfat/dir.c
@@ -562,38 +562,6 @@ int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync)
        return err;
 }
 
-static int exfat_walk_fat_chain(struct super_block *sb,
-               struct exfat_chain *p_dir, unsigned int byte_offset,
-               unsigned int *clu)
-{
-       struct exfat_sb_info *sbi = EXFAT_SB(sb);
-       unsigned int clu_offset;
-       unsigned int cur_clu;
-
-       clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi);
-       cur_clu = p_dir->dir;
-
-       if (p_dir->flags == ALLOC_NO_FAT_CHAIN) {
-               cur_clu += clu_offset;
-       } else {
-               while (clu_offset > 0) {
-                       if (exfat_get_next_cluster(sb, &cur_clu))
-                               return -EIO;
-                       if (cur_clu == EXFAT_EOF_CLUSTER) {
-                               exfat_fs_error(sb,
-                                       "invalid dentry access beyond EOF (clu : %u, eidx : %d)",
-                                       p_dir->dir,
-                                       EXFAT_B_TO_DEN(byte_offset));
-                               return -EIO;
-                       }
-                       clu_offset--;
-               }
-       }
-
-       *clu = cur_clu;
-       return 0;
-}
-
 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
                               int entry, sector_t *sector, int *offset)
 {
@@ -603,10 +571,19 @@ static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir
 
        off = EXFAT_DEN_TO_B(entry);
 
-       ret = exfat_walk_fat_chain(sb, p_dir, off, &clu);
+       clu = p_dir->dir;
+       ret = exfat_cluster_walk(sb, &clu, EXFAT_B_TO_CLU(off, sbi), p_dir->flags);
        if (ret)
                return ret;
 
+       if (clu == EXFAT_EOF_CLUSTER) {
+               exfat_fs_error(sb,
+                       "unexpected early break in cluster chain (clu : %u, len : %d)",
+                       p_dir->dir,
+                       EXFAT_B_TO_CLU(off, sbi));
+               return -EIO;
+       }
+
        if (!exfat_test_bitmap(sb, clu)) {
                exfat_err(sb, "failed to test cluster bit(%u)", clu);
                return -EIO;
@@ -792,9 +769,7 @@ static int __exfat_get_dentry_set(struct exfat_entry_set_cache *es,
                if (exfat_is_last_sector_in_cluster(sbi, sec)) {
                        unsigned int clu = exfat_sector_to_cluster(sbi, sec);
 
-                       if (p_dir->flags == ALLOC_NO_FAT_CHAIN)
-                               clu++;
-                       else if (exfat_get_next_cluster(sb, &clu))
+                       if (exfat_cluster_walk(sb, &clu, 1, p_dir->flags))
                                goto put_es;
                        sec = exfat_cluster_to_sector(sbi, clu);
                } else {

diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index beb9ea7cca9f9df4854ed59a770565194a62e985..cde2eb0f31ad775754b60d545c4f23f8c50e3db2 100644 (file)
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -225,15 +225,8 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
                 * *clu = (the first cluster of the allocated chain) =>
                 * (the last cluster of ...)
                 */
-               if (ei->flags == ALLOC_NO_FAT_CHAIN) {
-                       *clu += num_to_be_allocated - 1;
-               } else {
-                       while (num_to_be_allocated > 1) {
-                               if (exfat_get_next_cluster(sb, clu))
-                                       return -EIO;
-                               num_to_be_allocated--;
-                       }
-               }
+               if (exfat_cluster_walk(sb, clu, num_to_be_allocated - 1, ei->flags))
+                       return -EIO;
                *count = 1;
        }