[PATCH] ext4: fix reserved space counter leakage
From: Jeffle Xu <jefflexu@linux.alibaba.com>
Date: 2021-08-19 09:13:57
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
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: <redacted>
Reported-by: Gao Xiang <redacted>
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
---
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