When ext4_es_insert_delayed_block() returns error, e.g., ENOMEM,
previously reserved space is not released as the error handling,
in which case @s_dirtyclusters_counter is left over. Since this delayed
extent failes to be inserted into extent status tree, when inode is
written back, the extra @s_dirtyclusters_counter won't be subtracted and
remains there forever.
This can leads to /sys/fs/ext4/<dev>/delayed_allocation_blocks remains
non-zero even when syncfs is executed on the filesystem.
Fixes: 51865fda28e5 ("ext4: let ext4 maintain extent status tree")
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Signed-off-by: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 82087657860b..7f15da370281 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1650,6 +1650,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
int ret;
bool allocated = false;
+ bool reserved = false;
/*
* If the cluster containing lblk is shared with a delayed,
@@ -1666,6 +1667,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
ret = ext4_da_reserve_space(inode);
if (ret != 0) /* ENOSPC */
goto errout;
+ reserved = true;
} else { /* bigalloc */
if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) {
if (!ext4_es_scan_clu(inode,
@@ -1678,6 +1680,7 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
ret = ext4_da_reserve_space(inode);
if (ret != 0) /* ENOSPC */
goto errout;
+ reserved = true;
} else {
allocated = true;
}
@@ -1688,6 +1691,8 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
}
ret = ext4_es_insert_delayed_block(inode, lblk, allocated);
+ if (ret && reserved)
+ ext4_da_release_space(inode, 1);
errout:
return ret;
--
2.27.0
