[PATCH 5.10.y] 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>
[ bring error handling pattern closer to upstream ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 12da59c03c7cf..5572d2404eb3b 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3228,7 +3228,9 @@ 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 && err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
+		goto out_err;
+	if (!err)
 		goto out;
 
 	/*
@@ -3244,7 +3246,8 @@ static int 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 PTR_ERR(path);
+		err = PTR_ERR(path);
+		goto out_err;
 	}
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
@@ -3300,6 +3303,9 @@ static int ext4_split_extent_at(handle_t *handle,
 	 */
 	ext4_ext_dirty(handle, inode, path + path->p_depth);
 	return err;
+out_err:
+	/* Remove all remaining potentially stale extents. */
+	ext4_es_remove_extent(inode, ee_block, ee_len);
 out:
 	ext4_ext_show_leaf(inode, *ppath);
 	return err;
-- 
2.51.0