* Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>:
> 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.
>
Hi:
I think the fix below looks fine. However, this comment doesn't look right
to me. Are you really seeing delayed_allocation_blocks values that remain
incorrectly elevated across last closes (or across file system unmounts and
remounts)? s_dirtyclusters_counter isn't written out to stable storage -
it's an in-memory only variable that's created when a file is first opened
and destroyed on last close.
Eric
> 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
>
