fs: take the ACL checks to common code

Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 9508ad1..65a735d 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -30,7 +30,7 @@
 
 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 
-static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
+struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
 {
 	int size;
 	const char *name;
@@ -195,22 +195,6 @@
 	return ret;
 }
 
-int btrfs_check_acl(struct inode *inode, int mask)
-{
-	int error = -EAGAIN;
-	struct posix_acl *acl;
-
-	acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
-	if (IS_ERR(acl))
-		return PTR_ERR(acl);
-	if (acl) {
-		error = posix_acl_permission(inode, acl, mask);
-		posix_acl_release(acl);
-	}
-
-	return error;
-}
-
 /*
  * btrfs_init_acl is already generally called under fs_mutex, so the locking
  * stuff has been fixed to work with that.  If the locking stuff changes, we