[PATCH 15/18] flag parameters: NONBLOCK in timerfd_create

Ulrich Drepper
2008-05-06T21:25:24Z

This patch adds support for the TFD_NONBLOCK flag to timerfd_create. The
additional changes needed are minimal.

The following test must be adjusted for architectures other than x86 and
x86-64 and in case the syscall numbers changed.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <sys/syscall.h>

#ifndef __NR_timerfd_create
# ifdef __x86_64__
# define __NR_timerfd_create 283
# elif defined __i386__
# define __NR_timerfd_create 322
# else
# error "need __NR_timerfd_create"
# endif
#endif

#define TFD_NONBLOCK O_NONBLOCK

int
main (void)
{
int fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, 0);
if (fd == -1)
{
puts ("timerfd_create(0) failed");
return 1;
}
int fl = fcntl (fd, F_GETFL);
if (fl == -1)
{
puts ("fcntl failed");
return 1;
}
if (fl & O_NONBLOCK)
{
puts ("timerfd_create(0) set non-blocking mode");
return 1;
}
close (fd);

fd = syscall (__NR_timerfd_create, CLOCK_REALTIME, TFD_NONBLOCK);
if (fd == -1)
{
puts ("timerfd_create(TFD_NONBLOCK) failed");
return 1;
}
fl = fcntl (fd, F_GETFL);
if (fl == -1)
{
puts ("fcntl failed");
return 1;
}
if ((fl & O_NONBLOCK) == 0)
{
puts ("timerfd_create(TFD_NONBLOCK) set non-blocking mode");
return 1;
}
close (fd);

puts ("OK");

return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

fs/timerfd.c | 4 ++--
include/linux/timerfd.h | 3 ++-
2 files changed, 4 insertions(+), 3 deletions(-)

Signed-off-by: Ulrich Drepper <drepper@redhat.com>

diff --git a/fs/timerfd.c b/fs/timerfd.c
index c6ef5e3..75d44ef 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -184,7 +184,7 @@ asmlinkage long sys_timerfd_create(int clockid, int flags)
int ufd;
struct timerfd_ctx *ctx;

- if (flags & ~TFD_CLOEXEC)
+ if (flags & ~(TFD_CLOEXEC | TFD_NONBLOCK))
return -EINVAL;
if (clockid != CLOCK_MONOTONIC &&
clockid != CLOCK_REALTIME)
@@ -199,7 +199,7 @@ asmlinkage long sys_timerfd_create(int clockid, int flags)
hrtimer_init(&ctx->tmr, clockid, HRTIMER_MODE_ABS);

ufd = anon_inode_getfd("[timerfd]", &timerfd_fops, ctx,
- flags & O_CLOEXEC);
+ flags & (O_CLOEXEC | O_NONBLOCK));
if (ufd < 0)
kfree(ctx);

diff --git a/include/linux/timerfd.h b/include/linux/timerfd.h
index 96ed97d..86cb050 100644
--- a/include/linux/timerfd.h
+++ b/include/linux/timerfd.h
@@ -8,7 +8,7 @@
#ifndef _LINUX_TIMERFD_H
#define _LINUX_TIMERFD_H

-/* For O_CLOEXEC */
+/* For O_CLOEXEC and O_NONBLOCK */
#include <linux/fcntl.h>

/* Flags for timerfd_settime. */
@@ -16,6 +16,7 @@

/* Flags for timerfd_create. */
#define TFD_CLOEXEC O_CLOEXEC
+#define TFD_NONBLOCK O_NONBLOCK

#endif /* _LINUX_TIMERFD_H */