ext4: drop extent cache when splitting extent fails

commit 79b592e upstream.

When the split extent fails, we might leave some extents still being
processed and return an error directly, which will result in stale
extent entries remaining in the extent status tree. So drop all of the
remaining potentially stale extents if the splitting fails.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Cc: stable@kernel.org
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Message-ID: <20251129103247.686136-8-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: zhangyi089

fs/ext4/extents.c

@@ -3267,7 +3267,7 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
 
 	err = PTR_ERR(path);
 	if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
-		return path;
+		goto out_path;
 
 	/*
 	 * Get a new path to try to zeroout or fix the extent length.
@@ -3281,7 +3281,7 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
 	if (IS_ERR(path)) {
 		EXT4_ERROR_INODE(inode, "Failed split extent on %u, err %ld",
 				 split, PTR_ERR(path));
-		return path;
+		goto out_path;
 	}
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
@@ -3358,6 +3358,10 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
 		ext4_free_ext_path(path);
 		path = ERR_PTR(err);
 	}
+out_path:
+	if (IS_ERR(path))
+		/* Remove all remaining potentially stale extents. */
+		ext4_es_remove_extent(inode, ee_block, ee_len);
 	ext4_ext_show_leaf(inode, path);
 	return path;
 }