On 2023/2/14 19:48, Jan Kara wrote:
On Mon 13-02-23 12:05:21, zhanchengbin wrote:
If ENOMEM fails when the extent is splitting, we need to restore the length
of the split extent.
In the call stack of the ext4_split_extent_at function, only in
ext4_ext_create_new_leaf will it alloc memory and change the shape of the
extent tree,even if an ENOMEM is returned at this time, the extent tree is
still self-consistent, Just restore the split extent lens in the function
ext4_split_extent_at.
ext4_split_extent_at
ext4_ext_insert_extent
ext4_ext_create_new_leaf
1)ext4_ext_split
ext4_find_extent
2)ext4_ext_grow_indepth
ext4_find_extent
Signed-off-by: zhanchengbin <zhanchengbin1@xxxxxxxxxx>
---
fs/ext4/extents.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 9de1c9d1a13d..0f95e857089e 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -935,6 +935,7 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
bh = read_extent_tree_block(inode, path[ppos].p_idx, --i, flags);
if (IS_ERR(bh)) {
+ EXT4_ERROR_INODE(inode, "IO error reading extent block");
Why have you added this? Usually we don't log any additional errors for IO
errors because the storage layer already reports it... Furthermore this
would potentialy panic the system / remount the fs RO which we also usually
don't do in case of IO errors, only in case of FS corruption.
Honza
Because failure of read_extent_tree_block indirectly leads to filesystem
inconsistency in ext4_split_extent_at, I want the filesystem to become
read-only after failure.
- bin.
ret = PTR_ERR(bh);
goto err;
}
@@ -3251,7 +3252,7 @@ static int ext4_split_extent_at(handle_t *handle,
ext4_ext_mark_unwritten(ex2);
err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
- if (err != -ENOSPC && err != -EDQUOT)
+ if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
goto out;
if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
--
2.31.1
