mqueue: Convert message queue timeout to use hrtimers

The message queue functions mq_timedsend() and mq_timedreceive()
have not yet been converted to use the hrtimer interface.

This patch replaces the call to schedule_timeout() by a call to
schedule_hrtimeout() and transforms the expiration time from
timespec to ktime as required.

[ tglx: Fixed whitespace wreckage ]

Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Tested-by: Pradyumna Sampath <pradysam@gmail.com>
Cc: Arjan van de Veen <arjan@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20100402204331.715783034@osadl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index e4e3f04803ca9ec103da18837104042cc303e908..a9d8b0ced4e92d6d81700cf8cc53df7f20438081 100644 (file)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -428,7 +428,7 @@ static void wq_add(struct mqueue_inode_info *info, int sr,
  * sr: SEND or RECV
  */
 static int wq_sleep(struct mqueue_inode_info *info, int sr,
-                       long timeout, struct ext_wait_queue *ewp)
+                   ktime_t *timeout, struct ext_wait_queue *ewp)
 {
        int retval;
        signed long time;
@@ -439,7 +439,8 @@ static int wq_sleep(struct mqueue_inode_info *info, int sr,
                set_current_state(TASK_INTERRUPTIBLE);
 
                spin_unlock(&info->lock);
-               time = schedule_timeout(timeout);
+               time = schedule_hrtimeout_range_clock(timeout,
+                   HRTIMER_MODE_ABS, 0, CLOCK_REALTIME);
 
                while (ewp->state == STATE_PENDING)
                        cpu_relax();
@@ -551,31 +552,16 @@ static void __do_notify(struct mqueue_inode_info *info)
        wake_up(&info->wait_q);
 }
 
-static long prepare_timeout(struct timespec *p)
+static int prepare_timeout(const struct timespec __user *u_abs_timeout,
+                          ktime_t *expires, struct timespec *ts)
 {
-       struct timespec nowts;
-       long timeout;
-
-       if (p) {
-               if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0
-                       || p->tv_nsec >= NSEC_PER_SEC))
-                       return -EINVAL;
-               nowts = CURRENT_TIME;
-               /* first subtract as jiffies can't be too big */
-               p->tv_sec -= nowts.tv_sec;
-               if (p->tv_nsec < nowts.tv_nsec) {
-                       p->tv_nsec += NSEC_PER_SEC;
-                       p->tv_sec--;
-               }
-               p->tv_nsec -= nowts.tv_nsec;
-               if (p->tv_sec < 0)
-                       return 0;
-
-               timeout = timespec_to_jiffies(p) + 1;
-       } else
-               return MAX_SCHEDULE_TIMEOUT;
+       if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec)))
+               return -EFAULT;
+       if (!timespec_valid(ts))
+               return -EINVAL;
 
-       return timeout;
+       *expires = timespec_to_ktime(*ts);
+       return 0;
 }
 
 static void remove_notification(struct mqueue_inode_info *info)
@@ -861,22 +847,21 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
        struct ext_wait_queue *receiver;
        struct msg_msg *msg_ptr;
        struct mqueue_inode_info *info;
-       struct timespec ts, *p = NULL;
-       long timeout;
+       ktime_t expires, *timeout = NULL;
+       struct timespec ts;
        int ret;
 
        if (u_abs_timeout) {
-               if (copy_from_user(&ts, u_abs_timeout, 
-                                       sizeof(struct timespec)))
-                       return -EFAULT;
-               p = &ts;
+               int res = prepare_timeout(u_abs_timeout, &expires, &ts);
+               if (res)
+                       return res;
+               timeout = &expires;
        }
 
        if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
                return -EINVAL;
 
-       audit_mq_sendrecv(mqdes, msg_len, msg_prio, p);
-       timeout = prepare_timeout(p);
+       audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL);
 
        filp = fget(mqdes);
        if (unlikely(!filp)) {
@@ -918,9 +903,6 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
                if (filp->f_flags & O_NONBLOCK) {
                        spin_unlock(&info->lock);
                        ret = -EAGAIN;
-               } else if (unlikely(timeout < 0)) {
-                       spin_unlock(&info->lock);
-                       ret = timeout;
                } else {
                        wait.task = current;
                        wait.msg = (void *) msg_ptr;
@@ -953,24 +935,23 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
                size_t, msg_len, unsigned int __user *, u_msg_prio,
                const struct timespec __user *, u_abs_timeout)
 {
-       long timeout;
        ssize_t ret;
        struct msg_msg *msg_ptr;
        struct file *filp;
        struct inode *inode;
        struct mqueue_inode_info *info;
        struct ext_wait_queue wait;
-       struct timespec ts, *p = NULL;
+       ktime_t expires, *timeout = NULL;
+       struct timespec ts;
 
        if (u_abs_timeout) {
-               if (copy_from_user(&ts, u_abs_timeout, 
-                                       sizeof(struct timespec)))
-                       return -EFAULT;
-               p = &ts;
+               int res = prepare_timeout(u_abs_timeout, &expires, &ts);
+               if (res)
+                       return res;
+               timeout = &expires;
        }
 
-       audit_mq_sendrecv(mqdes, msg_len, 0, p);
-       timeout = prepare_timeout(p);
+       audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL);
 
        filp = fget(mqdes);
        if (unlikely(!filp)) {
@@ -1002,11 +983,6 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
                if (filp->f_flags & O_NONBLOCK) {
                        spin_unlock(&info->lock);
                        ret = -EAGAIN;
-                       msg_ptr = NULL;
-               } else if (unlikely(timeout < 0)) {
-                       spin_unlock(&info->lock);
-                       ret = timeout;
-                       msg_ptr = NULL;
                } else {
                        wait.task = current;
                        wait.state = STATE_NONE;