From 3a18ef5c1b3935cb05888fc37964321f7bd6231d Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 11 Mar 2018 11:34:40 +0100 Subject: fs: add ksys_umount() helper; remove in-kernel call to sys_umount() Using this helper allows us to avoid the in-kernel call to the sys_umount() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as ksys_umount(). In the near future, the only fs-external caller of ksys_umount() should be converted to call do_umount() directly. Then, ksys_umount() can be moved within sys_umount() again. 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 Cc: Alexander Viro Signed-off-by: Dominik Brodowski --- fs/namespace.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'fs/namespace.c') diff --git a/fs/namespace.c b/fs/namespace.c index 642b8b229944..e398f32d7541 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1680,7 +1680,7 @@ static inline bool may_mandlock(void) * unixes. Our API is identical to OSF/1 to avoid making a mess of AMD */ -SYSCALL_DEFINE2(umount, char __user *, name, int, flags) +int ksys_umount(char __user *name, int flags) { struct path path; struct mount *mnt; @@ -1720,6 +1720,11 @@ out: return retval; } +SYSCALL_DEFINE2(umount, char __user *, name, int, flags) +{ + return ksys_umount(name, flags); +} + #ifdef __ARCH_WANT_SYS_OLDUMOUNT /* @@ -1727,7 +1732,7 @@ out: */ SYSCALL_DEFINE1(oldumount, char __user *, name) { - return sys_umount(name, 0); + return ksys_umount(name, 0); } #endif -- cgit