The patch below does not apply to the 3.17-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 093a1468b6edb0e568be7311b8d2228d205702db Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date: Wed, 12 Nov 2014 18:04:04 -0500
Subject: [PATCH] SUNRPC: Fix locking around callback channel reply receive
Both xprt_lookup_rqst() and xprt_complete_rqst() require that you
take the transport lock in order to avoid races with xprt_transmit().
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 3f959c681885..f9c052d508f0 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1019,17 +1019,12 @@ static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
xid = *p++;
calldir = *p;
- if (bc_xprt)
- req = xprt_lookup_rqst(bc_xprt, xid);
-
- if (!req) {
- printk(KERN_NOTICE
- "%s: Got unrecognized reply: "
- "calldir 0x%x xpt_bc_xprt %p xid %08x\n",
- __func__, ntohl(calldir),
- bc_xprt, ntohl(xid));
+ if (!bc_xprt)
return -EAGAIN;
- }
+ spin_lock_bh(&bc_xprt->transport_lock);
+ req = xprt_lookup_rqst(bc_xprt, xid);
+ if (!req)
+ goto unlock_notfound;
memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
/*
@@ -1040,11 +1035,21 @@ static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
dst = &req->rq_private_buf.head[0];
src = &rqstp->rq_arg.head[0];
if (dst->iov_len < src->iov_len)
- return -EAGAIN; /* whatever; just giving up. */
+ goto unlock_eagain; /* whatever; just giving up. */
memcpy(dst->iov_base, src->iov_base, src->iov_len);
xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
rqstp->rq_arg.len = 0;
+ spin_unlock_bh(&bc_xprt->transport_lock);
return 0;
+unlock_notfound:
+ printk(KERN_NOTICE
+ "%s: Got unrecognized reply: "
+ "calldir 0x%x xpt_bc_xprt %p xid %08x\n",
+ __func__, ntohl(calldir),
+ bc_xprt, ntohl(xid));
+unlock_eagain:
+ spin_unlock_bh(&bc_xprt->transport_lock);
+ return -EAGAIN;
}
static int copy_pages_to_kvecs(struct kvec *vec, struct page **pages, int len)
--
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