ext2: check xattr name_len before acquiring xattr_sem in ext2_xattr_get
In ext2_xattr_get(), the code will acquire xattr_sem first, later checks
the length of xattr name_len > 255. It's unnecessarily time consuming and
also ext2_xattr_set() checks the length before other checks. So move the
check before acquiring xattr_sem to make these two functions consistent.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index 5299706..d27b71f 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -161,6 +161,10 @@
if (name == NULL)
return -EINVAL;
+ name_len = strlen(name);
+ if (name_len > 255)
+ return -ERANGE;
+
down_read(&EXT2_I(inode)->xattr_sem);
error = -ENODATA;
if (!EXT2_I(inode)->i_file_acl)
@@ -181,12 +185,8 @@
error = -EIO;
goto cleanup;
}
- /* find named attribute */
- name_len = strlen(name);
- error = -ERANGE;
- if (name_len > 255)
- goto cleanup;
+ /* find named attribute */
entry = FIRST_ENTRY(bh);
while (!IS_LAST_ENTRY(entry)) {
struct ext2_xattr_entry *next =