diff options
| author | Benjamin Coddington <bcodding@redhat.com> | 2017-07-28 12:33:54 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-06 18:59:40 -0700 |
| commit | 7d2a354861e9257824a201d39a11e6a4d2a60cb4 (patch) | |
| tree | 29da0e252c4e96f3da4d15db1708de15151f391e | |
| parent | b087b8b11e52f3ae9278d01f62db7cddb7236fee (diff) | |
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 <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/nfs/nfs4proc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 401ea6e4cab8..46ca7881d80d 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); |