[PATCH v3 2/2] ext4: restore len when ext4_ext_insert_extent failed

[zhanchengbin <zhanchengbin1@huawei.com>]

Inside the ext4_ext_insert_extent function, every error returned will
not destroy the consistency of the tree. Even if it fails after changing
half of the tree, can also ensure that the tree is self-consistent, like
function ext4_ext_create_new_leaf.
After ext4_ext_insert_extent fails, update extent status tree depends on
the incoming split_flag. So restore the len of extent to be split when
ext4_ext_insert_extent return failed in ext4_split_extent_at.

Signed-off-by: zhanchengbin <zhanchengbin1@huawei.com>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 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 3559ea6b0781..b926fef73de4 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");
 			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 && err != -ENOMEM)
+	if (!err)
 		goto out;
 
 	if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
-- 
2.31.1