[PATCH 6.1.y 6/6] ext4: drop extent cache when splitting extent fails

[Sasha Levin <sashal@kernel.org>]

From: Zhang Yi <yi.zhang@huawei.com>

[ Upstream commit 79b592e8f1b435796cbc2722190368e3e8ffd7a1 ]

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: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 476fa4bc351a0..90f0610cfbc0c 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3243,7 +3243,7 @@ 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.
@@ -3257,7 +3257,7 @@ 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;
@@ -3317,6 +3317,10 @@ 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;
 }
-- 
2.51.0