From: Benjamin Coddington Date: Fri, 28 Jul 2017 16:33:54 +0000 (-0400) Subject: NFSv4.1: Fix a race where CB_NOTIFY_LOCK fails to wake a waiter X-Git-Tag: v4.9.41~94 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7d2a354861e9257824a201d39a11e6a4d2a60cb4;p=platform%2Fkernel%2Flinux-amlogic.git NFSv4.1: Fix a race where CB_NOTIFY_LOCK fails to wake a waiter commit b7dbcc0e433f0f61acb89ed9861ec996be4f2b38 upstream. 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 Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 401ea6e..46ca788 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6419,7 +6419,7 @@ 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);