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>

1 files changed, 25 insertions, 49 deletions

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index e4e3f04803ca..a9d8b0ced4e9 100644
--- 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;