From: Theodore Ts'o tytso@mit.edu
[ Upstream commit 308c57ccf4318236be75dfa251c84713e694457b ]
If the underlying storage device is using thin-provisioning, it's possible for a zeroout operation to return ENOSPC.
Commit df22291ff0fd ("ext4: Retry block allocation if we have free blocks left") added logic to retry block allocation since we might get free block after we commit a transaction. But the ENOSPC from thin-provisioning will confuse ext4, and lead to an infinite loop.
Since using zeroout instead of splitting the extent node is an optimization, if it fails, we might as well fall back to splitting the extent node.
Reported-by: yangerkun yangerkun@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/extents.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 1293de50c8d4..ea699ce9ff5e 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3568,7 +3568,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, split_map.m_len - ee_block); err = ext4_ext_zeroout(inode, &zero_ex1); if (err) - goto out; + goto fallback; split_map.m_len = allocated; } if (split_map.m_lblk - ee_block + split_map.m_len < @@ -3582,7 +3582,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, ext4_ext_pblock(ex)); err = ext4_ext_zeroout(inode, &zero_ex2); if (err) - goto out; + goto fallback; }
split_map.m_len += split_map.m_lblk - ee_block; @@ -3591,6 +3591,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, } }
+fallback: err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag, flags); if (err > 0)