3.2.99-rc1 review patch. If anyone has any objections, please let me know.
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From: Tuomas Tynkkynen tuomas@tuxera.com
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 --- --- a/net/9p/client.c +++ b/net/9p/client.c @@ -740,8 +740,7 @@ p9_client_rpc(struct p9_client *c, int8_ 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); --- 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 vi * 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 */