From: Tuomas Tynkkynen <tuomas@tuxera.com>
Date: Wed, 6 Sep 2017 14:59:08 +0000 (+0300)
Subject: net/9p: Switch to wait_event_killable()
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=78124e9bcc8c39afbcda2f0500b868dd0b159d40;p=pandora-kernel.git

net/9p: Switch to wait_event_killable()

commit 9523feac272ccad2ad8186ba4fcc89103754de52 upstream.

Because userspace gets Very Unhappy when calls like stat() and execve()
return -EINTR on 9p filesystem mounts. For instance, when bash is
looking in PATH for things to execute and some SIGCHLD interrupts
stat(), bash can throw a spurious 'command not found' since it doesn't
retry the stat().

In practice, hitting the problem is rare and needs a really
slow/bogged down 9p server.

Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2:
 - Drop changes in trans_xen.c
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/net/9p/client.c b/net/9p/client.c
index 87173bb26410..3e61ba193bd9 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -740,8 +740,7 @@ p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 		goto reterr;
 	}
 	/* Wait for the response */
-	err = wait_event_interruptible(*req->wq,
-				       req->status >= REQ_STATUS_RCVD);
+	err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
 
 	if (req->status == REQ_STATUS_ERROR) {
 		P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 55f0c09da5a4..0a05ac1056ef 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -276,8 +276,8 @@ req_retry:
 		if (err == -ENOSPC) {
 			chan->ring_bufs_avail = 0;
 			spin_unlock_irqrestore(&chan->lock, flags);
-			err = wait_event_interruptible(*chan->vc_wq,
-							chan->ring_bufs_avail);
+			err = wait_event_killable(*chan->vc_wq,
+						  chan->ring_bufs_avail);
 			if (err  == -ERESTARTSYS)
 				return err;
 
@@ -309,7 +309,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
 		 * Other zc request to finish here
 		 */
 		if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
-			err = wait_event_interruptible(vp_wq,
+			err = wait_event_killable(vp_wq,
 			      (atomic_read(&vp_pinned) < chan->p9_max_pages));
 			if (err == -ERESTARTSYS)
 				return err;
@@ -419,8 +419,8 @@ req_retry_pinned:
 		if (err == -ENOSPC) {
 			chan->ring_bufs_avail = 0;
 			spin_unlock_irqrestore(&chan->lock, flags);
-			err = wait_event_interruptible(*chan->vc_wq,
-						       chan->ring_bufs_avail);
+			err = wait_event_killable(*chan->vc_wq,
+						  chan->ring_bufs_avail);
 			if (err  == -ERESTARTSYS)
 				goto err_out;
 
@@ -438,8 +438,7 @@ req_retry_pinned:
 	virtqueue_kick(chan->vq);
 	spin_unlock_irqrestore(&chan->lock, flags);
 	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");
-	err = wait_event_interruptible(*req->wq,
-				       req->status >= REQ_STATUS_RCVD);
+	err = wait_event_killable(*req->wq, req->status >= REQ_STATUS_RCVD);
 	/*
 	 * Non kernel buffers are pinned, unpin them
 	 */