From: Theodore Ts'o <tytso(a)mit.edu>
mainline inclusion
from mainline-5.15-rc1
commit 308c57ccf4318236be75dfa251c84713e694457b
category: bugfix
bugzilla: 109297
CVE: NA
---------------------------
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(a)huawei.com>
Signed-off-by: Theodore Ts'o <tytso(a)mit.edu>
Signed-off-by: yangerkun <yangerkun(a)huawei.com>
Reviewed-by: Zhang Yi <yi.zhang(a)huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
---
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 fc00a78163117..10298c13a67d7 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3696,7 +3696,7 @@ 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 <
@@ -3710,7 +3710,7 @@ 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;
@@ -3719,6 +3719,7 @@ 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)
--
2.25.1