fanotify: add do_fanotify_mark() helper; remove in-kernel call to syscall

Using the fs-internal do_fanotify_mark() helper allows us to get rid of
the fs-internal call to the sys_fanotify_mark() syscall.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Acked-by: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index c07eb3d..fa803a5 100644 (file)
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -820,9 +820,8 @@ out_destroy_group:
        return fd;
 }
 
-SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
-                             __u64, mask, int, dfd,
-                             const char  __user *, pathname)
+static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
+                           int dfd, const char  __user *pathname)
 {
        struct inode *inode = NULL;
        struct vfsmount *mnt = NULL;
@@ -928,13 +927,20 @@ fput_and_out:
        return ret;
 }
 
+SYSCALL_DEFINE5(fanotify_mark, int, fanotify_fd, unsigned int, flags,
+                             __u64, mask, int, dfd,
+                             const char  __user *, pathname)
+{
+       return do_fanotify_mark(fanotify_fd, flags, mask, dfd, pathname);
+}
+
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE6(fanotify_mark,
                                int, fanotify_fd, unsigned int, flags,
                                __u32, mask0, __u32, mask1, int, dfd,
                                const char  __user *, pathname)
 {
-       return sys_fanotify_mark(fanotify_fd, flags,
+       return do_fanotify_mark(fanotify_fd, flags,
 #ifdef __BIG_ENDIAN
                                ((__u64)mask0 << 32) | mask1,
 #else