vfs: Distinguish between full xattr names and proper prefixes

Add an additional "name" field to struct xattr_handler.  When the name
is set, the handler matches attributes with exactly that name.  When the
prefix is set instead, the handler matches attributes with the given
prefix and with a non-empty suffix.

This patch should avoid bugs like the one fixed in commit c361016a in
the future.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 0 insertions, 6 deletions

diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 7288795718c9..36a43851aac0 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -39,9 +39,6 @@ xfs_xattr_get(const struct xattr_handler *handler, struct dentry *dentry,
         struct xfs_inode *ip = XFS_I(d_inode(dentry));
         int error, asize = size;
 
-        if (strcmp(name, "") == 0)
-                return -EINVAL;
-
         /* Convert Linux syscall to XFS internal ATTR flags */
         if (!size) {
                 xflags |= ATTR_KERNOVAL;
@@ -84,9 +81,6 @@ xfs_xattr_set(const struct xattr_handler *handler, struct dentry *dentry,
         struct xfs_inode        *ip = XFS_I(d_inode(dentry));
         int                     error;
 
-        if (strcmp(name, "") == 0)
-                return -EINVAL;
-
         /* Convert Linux syscall to XFS internal ATTR flags */
         if (flags & XATTR_CREATE)
                 xflags |= ATTR_CREATE;