5.15-stable review patch. If anyone has any objections, please let me know.
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From: Namjae Jeon linkinjeon@kernel.org
[ Upstream commit 9da33619e0ca53627641bc97d1b93ec741299111 ]
bitmap clear loop will take long time in __exfat_free_cluster() if data size of file/dir enty is invalid. If cluster bit in bitmap is already clear, stop clearing bitmap go to out of loop.
Fixes: 31023864e67a ("exfat: add fat entry operations") Reported-by: Kun Hu huk23@m.fudan.edu.cn, Jiaji Qin jjtan24@m.fudan.edu.cn Reviewed-by: Sungjong Seo sj1557.seo@samsung.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/exfat/balloc.c | 10 ++++++++-- fs/exfat/exfat_fs.h | 2 +- fs/exfat/fatent.c | 11 +++++++---- 3 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/fs/exfat/balloc.c b/fs/exfat/balloc.c index 144617066a2bf..26808f0d3e9ff 100644 --- a/fs/exfat/balloc.c +++ b/fs/exfat/balloc.c @@ -160,7 +160,7 @@ int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync) return 0; }
-void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync) +int exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync) { int i, b; unsigned int ent_idx; @@ -169,13 +169,17 @@ void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync) struct exfat_mount_options *opts = &sbi->options;
if (!is_valid_cluster(sbi, clu)) - return; + return -EIO;
ent_idx = CLUSTER_TO_BITMAP_ENT(clu); i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx); b = BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent_idx);
+ if (!test_bit_le(b, sbi->vol_amap[i]->b_data)) + return -EIO; + clear_bit_le(b, sbi->vol_amap[i]->b_data); + exfat_update_bh(sbi->vol_amap[i], sync);
if (opts->discard) { @@ -190,6 +194,8 @@ void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync) opts->discard = 0; } } + + return 0; }
/* diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index 58816ee3162c4..e242d7758f782 100644 --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -420,7 +420,7 @@ int exfat_count_num_clusters(struct super_block *sb, int exfat_load_bitmap(struct super_block *sb); void exfat_free_bitmap(struct exfat_sb_info *sbi); int exfat_set_bitmap(struct inode *inode, unsigned int clu, bool sync); -void exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync); +int exfat_clear_bitmap(struct inode *inode, unsigned int clu, bool sync); unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu); int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count); int exfat_trim_fs(struct inode *inode, struct fstrim_range *range); diff --git a/fs/exfat/fatent.c b/fs/exfat/fatent.c index 8f07504e53458..9c116a58544da 100644 --- a/fs/exfat/fatent.c +++ b/fs/exfat/fatent.c @@ -174,6 +174,7 @@ 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; @@ -188,7 +189,9 @@ 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); @@ -209,12 +212,13 @@ 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) { /* @@ -228,7 +232,6 @@ static int __exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain } while (clu != EXFAT_EOF_CLUSTER); }
-dec_used_clus: sbi->used_clusters -= num_clusters; return 0; }