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authorVenkateswararao Jujjuri (JV) <jvrao@linux.vnet.ibm.com>2010-09-29 18:06:54 -0700
committerEric Van Hensbergen <ericvh@gmail.com>2010-10-28 09:08:48 -0500
commit419b39561e698d73a42f8010655d22e0134486da (patch)
tree76b6bd98dcaaa89d27b2d804d1ed67f049f070bd /net
parent329176cc2c50e63c580ddaabb385876db5af1360 (diff)
downloadlinux-2.6.38-lt-ux500-419b39561e698d73a42f8010655d22e0134486da.tar.gz
[net/9p]Serialize virtqueue operations to make VirtIO transport SMP safe.
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'net')
-rw-r--r--net/9p/trans_virtio.c34
1 files changed, 24 insertions, 10 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index b88515936e4..8ae08596aad 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -134,16 +134,24 @@ static void req_done(struct virtqueue *vq)
struct p9_fcall *rc;
unsigned int len;
struct p9_req_t *req;
+ unsigned long flags;
P9_DPRINTK(P9_DEBUG_TRANS, ": request done\n");
- while ((rc = virtqueue_get_buf(chan->vq, &len)) != NULL) {
- P9_DPRINTK(P9_DEBUG_TRANS, ": rc %p\n", rc);
- P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);
- req = p9_tag_lookup(chan->client, rc->tag);
- req->status = REQ_STATUS_RCVD;
- p9_client_cb(chan->client, req);
- }
+ do {
+ spin_lock_irqsave(&chan->lock, flags);
+ rc = virtqueue_get_buf(chan->vq, &len);
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ if (rc != NULL) {
+ P9_DPRINTK(P9_DEBUG_TRANS, ": rc %p\n", rc);
+ P9_DPRINTK(P9_DEBUG_TRANS, ": lookup tag %d\n",
+ rc->tag);
+ req = p9_tag_lookup(chan->client, rc->tag);
+ req->status = REQ_STATUS_RCVD;
+ p9_client_cb(chan->client, req);
+ }
+ } while (rc != NULL);
}
/**
@@ -199,23 +207,29 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
int in, out;
struct virtio_chan *chan = client->trans;
char *rdata = (char *)req->rc+sizeof(struct p9_fcall);
+ unsigned long flags;
+ int err;
P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request\n");
+ req->status = REQ_STATUS_SENT;
+
+ spin_lock_irqsave(&chan->lock, flags);
out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, req->tc->sdata,
req->tc->size);
in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata,
client->msize);
- req->status = REQ_STATUS_SENT;
-
- if (virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc) < 0) {
+ err = virtqueue_add_buf(chan->vq, chan->sg, out, in, req->tc);
+ if (err < 0) {
+ spin_unlock_irqrestore(&chan->lock, flags);
P9_DPRINTK(P9_DEBUG_TRANS,
"9p debug: virtio rpc add_buf returned failure");
return -EIO;
}
virtqueue_kick(chan->vq);
+ spin_unlock_irqrestore(&chan->lock, flags);
P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio request kicked\n");
return 0;