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>

1 files changed, 5 insertions, 5 deletions

diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index 529970617a21..d27b71f1d183 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -161,6 +161,10 @@ ext2_xattr_get(struct inode *inode, int name_index, const char *name,
 
         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 @@ bad_block:	ext2_error(inode->i_sb, "ext2_xattr_get",
                 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 =