Using this helper allows us to avoid the in-kernel calls to the sys_sync() 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 sys_sync(). 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@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- arch/sparc/kernel/setup_32.c | 2 +- drivers/tty/sysrq.c | 2 +- fs/sync.c | 7 ++++++- include/linux/syscalls.h | 1 + kernel/power/hibernate.c | 2 +- kernel/power/suspend.c | 2 +- kernel/power/user.c | 2 +- 7 files changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c index 2e3a3e203061..13664c377196 100644 --- a/arch/sparc/kernel/setup_32.c +++ b/arch/sparc/kernel/setup_32.c @@ -86,7 +86,7 @@ static void prom_sync_me(void) show_free_areas(0, NULL); if (!is_idle_task(current)) { local_irq_enable(); - sys_sync(); + ksys_sync(); local_irq_disable(); } prom_printf("Returning to prom\n"); diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c index b674793be478..6364890575ec 100644 --- a/drivers/tty/sysrq.c +++ b/drivers/tty/sysrq.c @@ -660,7 +660,7 @@ static void sysrq_do_reset(struct timer_list *t) state->reset_requested = true; - sys_sync(); + ksys_sync(); kernel_restart(NULL); } diff --git a/fs/sync.c b/fs/sync.c index 6e0a2cbaf6de..602ae94bb67e 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -105,7 +105,7 @@ static void fdatawait_one_bdev(struct block_device *bdev, void *arg) * just write metadata (such as inodes or bitmaps) to block device page cache * and do not sync it on their own in ->sync_fs(). */ -SYSCALL_DEFINE0(sync) +void ksys_sync(void) { int nowait = 0, wait = 1; @@ -117,6 +117,11 @@ SYSCALL_DEFINE0(sync) iterate_bdevs(fdatawait_one_bdev, NULL); if (unlikely(laptop_mode)) laptop_sync_completion(); +} + +SYSCALL_DEFINE0(sync) +{ + ksys_sync(); return 0; } diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 3a2e90842ff8..0a9942b3e718 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -960,6 +960,7 @@ int ksys_getdents64(unsigned int fd, struct linux_dirent64 __user *dirent, int ksys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg); off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence); ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count); +void ksys_sync(void); /* * The following kernel syscall equivalents are just wrappers to fs-internal diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index a5c36e9c56a6..4710f1b142fc 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -701,7 +701,7 @@ int hibernate(void) } pr_info("Syncing filesystems ... \n"); - sys_sync(); + ksys_sync(); pr_info("done.\n"); error = freeze_processes(); diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 0685c4499431..4c10be0f4843 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -560,7 +560,7 @@ static int enter_state(suspend_state_t state) #ifndef CONFIG_SUSPEND_SKIP_SYNC trace_suspend_resume(TPS("sync_filesystems"), 0, true); pr_info("Syncing filesystems ... "); - sys_sync(); + ksys_sync(); pr_cont("done.\n"); trace_suspend_resume(TPS("sync_filesystems"), 0, false); #endif diff --git a/kernel/power/user.c b/kernel/power/user.c index 22df9f7ff672..75c959de4b29 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -224,7 +224,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, break; printk("Syncing filesystems ... "); - sys_sync(); + ksys_sync(); printk("done.\n"); error = freeze_processes(); -- 2.16.3
