ext4: return error on ext4_find_inline_entry

In case of errors when reading an inode from disk or traversing inline
directory entries, return an error-encoded ERR_PTR instead of returning
NULL. ext4_find_inline_entry only caller, __ext4_find_entry already returns
such encoded errors.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Link: https://patch.msgid.link/20240821152324.3621860-3-cascardo@igalia.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/inline.c

@@ -1669,8 +1669,9 @@ struct buffer_head *ext4_find_inline_entry(struct inode *dir,
 	void *inline_start;
 	int inline_size;
 
-	if (ext4_get_inode_loc(dir, &iloc))
-		return NULL;
+	ret = ext4_get_inode_loc(dir, &iloc);
+	if (ret)
+		return ERR_PTR(ret);
 
 	down_read(&EXT4_I(dir)->xattr_sem);
 	if (!ext4_has_inline_data(dir)) {
@@ -1701,7 +1702,10 @@ struct buffer_head *ext4_find_inline_entry(struct inode *dir,
 
 out:
 	brelse(iloc.bh);
-	iloc.bh = NULL;
+	if (ret < 0)
+		iloc.bh = ERR_PTR(ret);
+	else
+		iloc.bh = NULL;
 out_find:
 	up_read(&EXT4_I(dir)->xattr_sem);
 	return iloc.bh;