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Code Issues Releases Wiki Activity

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@primarydata.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Trond Myklebust 2014-11-12 18:04:04 -05:00 committed by J. Bruce Fields
parent 6d0ba0432a
commit 093a1468b6
1 changed files with 16 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
net/sunrpc/svcsock.c
View File

@ -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)