diff options
Diffstat (limited to 'fs/exfat/fatent.c')
| -rw-r--r-- | fs/exfat/fatent.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c index 56b870d9cc0d..0c60ddc24c54 100644 --- a/fs/exfat/fatent.c +++ b/fs/exfat/fatent.c @@ -4,7 +4,7 @@ */ #include <linux/slab.h> -#include <asm/unaligned.h> +#include <linux/unaligned.h> #include <linux/buffer_head.h> #include <linux/blkdev.h> @@ -175,6 +175,7 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain BITMAP_OFFSET_SECTOR_INDEX(sb, CLUSTER_TO_BITMAP_ENT(clu)); if (p_chain->flags == ALLOC_NO_FAT_CHAIN) { + int err; unsigned int last_cluster = p_chain->dir + p_chain->size - 1; do { bool sync = false; @@ -189,7 +190,9 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain cur_cmap_i = next_cmap_i; } - exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode))); + err = exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode))); + if (err) + break; clu++; num_clusters++; } while (num_clusters < p_chain->size); @@ -210,16 +213,26 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain cur_cmap_i = next_cmap_i; } - exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode))); + if (exfat_clear_bitmap(inode, clu, (sync && IS_DIRSYNC(inode)))) + break; clu = n_clu; num_clusters++; if (err) - goto dec_used_clus; + break; + + if (num_clusters >= sbi->num_clusters - EXFAT_FIRST_CLUSTER) { + /* + * The cluster chain includes a loop, scan the + * bitmap to get the number of used clusters. + */ + exfat_count_used_clusters(sb, &sbi->used_clusters); + + return 0; + } } while (clu != EXFAT_EOF_CLUSTER); } -dec_used_clus: sbi->used_clusters -= num_clusters; return 0; } @@ -252,7 +265,7 @@ int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain, clu = next; if (exfat_ent_get(sb, clu, &next)) return -EIO; - } while (next != EXFAT_EOF_CLUSTER); + } while (next != EXFAT_EOF_CLUSTER && count <= p_chain->size); if (p_chain->size != count) { exfat_fs_error(sb, @@ -448,5 +461,15 @@ int exfat_count_num_clusters(struct super_block *sb, } *ret_count = count; + + /* + * since exfat_count_used_clusters() is not called, sbi->used_clusters + * cannot be used here. + */ + if (unlikely(i == sbi->num_clusters && clu != EXFAT_EOF_CLUSTER)) { + exfat_fs_error(sb, "The cluster chain has a loop"); + return -EIO; + } + return 0; } |