[PATCH] 9pnet: Use list_del_init when removing req_list elements

[Tom Tucker <tom@opengridcomputing.com>]

The p9_req_t structures are reused when tags are reused. For this reason,
the req_list list heads need to be re-initialized when deleted or a
subsequent list_add can corrupt the list and/or BUG_ON if list debug is
enabled.
    
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
---
 net/9p/trans_fd.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 1df0356..fc78336 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -213,7 +213,7 @@ static void p9_conn_cancel(struct p9_conn *m, int err)
 	spin_unlock_irqrestore(&m->client->lock, flags);
 
 	list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
-		list_del(&req->req_list);
+		list_del_init(&req->req_list);
 		P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
 		p9_client_cb(m->client, req);
 	}
@@ -361,7 +361,7 @@ static void p9_read_work(struct work_struct *work)
 	if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
 		P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
 		spin_lock(&m->client->lock);
-		list_del(&m->req->req_list);
+		list_del_init(&m->req->req_list);
 		spin_unlock(&m->client->lock);
 		p9_client_cb(m->client, m->req);
 
@@ -683,7 +683,7 @@ static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
 	P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 
 	spin_lock(&client->lock);
-	list_del(&req->req_list);
+	list_del_init(&req->req_list);
 
 	if (req->status == REQ_STATUS_UNSENT) {
 		req->status = REQ_STATUS_FLSHD;