| Message ID | 14a33c6c2f7502313c7c46a0b1fd977b0b9ccad2.1501258923.git.bcodding@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 2017-07-28 at 12:33 -0400, Benjamin Coddington wrote: > nfs4_retry_setlk() sets the task's state to TASK_INTERRUPTIBLE within the > same region protected by the wait_queue's lock after checking for a > notification from CB_NOTIFY_LOCK callback. However, after releasing that > lock, a wakeup for that task may race in before the call to > freezable_schedule_timeout_interruptible() and set TASK_WAKING, then > freezable_schedule_timeout_interruptible() will set the state back to > TASK_INTERRUPTIBLE before the task will sleep. The result is that the task > will sleep for the entire duration of the timeout. > > Since we've already set TASK_INTERRUPTIBLE in the locked section, just use > freezable_schedule_timout() instead. > > Fixes: a1d617d8f134 ("nfs: allow blocking locks to be awoken by lock callbacks") > Signed-off-by: Benjamin Coddington <bcodding@redhat.com> > --- > fs/nfs/nfs4proc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index dbfa18900e25..f5a7faac39a7 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -6441,7 +6441,7 @@ nfs4_retry_setlk(struct nfs4_state *state, int cmd, struct file_lock *request) > set_current_state(TASK_INTERRUPTIBLE); > spin_unlock_irqrestore(&q->lock, flags); > > - freezable_schedule_timeout_interruptible(NFS4_LOCK_MAXTIMEOUT); > + freezable_schedule_timeout(NFS4_LOCK_MAXTIMEOUT); > } > > finish_wait(q, &wait); Nice catch! Reviewed-by: Jeff Layton <jlayton@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index dbfa18900e25..f5a7faac39a7 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6441,7 +6441,7 @@ nfs4_retry_setlk(struct nfs4_state *state, int cmd, struct file_lock *request) set_current_state(TASK_INTERRUPTIBLE); spin_unlock_irqrestore(&q->lock, flags); - freezable_schedule_timeout_interruptible(NFS4_LOCK_MAXTIMEOUT); + freezable_schedule_timeout(NFS4_LOCK_MAXTIMEOUT); } finish_wait(q, &wait);
nfs4_retry_setlk() sets the task's state to TASK_INTERRUPTIBLE within the same region protected by the wait_queue's lock after checking for a notification from CB_NOTIFY_LOCK callback. However, after releasing that lock, a wakeup for that task may race in before the call to freezable_schedule_timeout_interruptible() and set TASK_WAKING, then freezable_schedule_timeout_interruptible() will set the state back to TASK_INTERRUPTIBLE before the task will sleep. The result is that the task will sleep for the entire duration of the timeout. Since we've already set TASK_INTERRUPTIBLE in the locked section, just use freezable_schedule_timout() instead. Fixes: a1d617d8f134 ("nfs: allow blocking locks to be awoken by lock callbacks") Signed-off-by: Benjamin Coddington <bcodding@redhat.com> --- fs/nfs/nfs4proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)