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authorNeilBrown <neilb@suse.de>2023-05-09 09:42:47 +1000
committerChuck Lever <chuck.lever@oracle.com>2023-05-14 15:55:02 -0400
commit948f072ada23e0a504c5e4d7d71d4c83bd0785ec (patch)
tree35e02b9a854af2107953dc9e7150bc98be37e453 /net
parenteb8d3a2c809abd73ab0a060fe971d6b9019aa3c1 (diff)
SUNRPC: always free ctxt when freeing deferred request
Since the ->xprt_ctxt pointer was added to svc_deferred_req, it has not been sufficient to use kfree() to free a deferred request. We may need to free the ctxt as well. As freeing the ctxt is all that ->xpo_release_rqst() does, we repurpose it to explicit do that even when the ctxt is not stored in an rqst. So we now have ->xpo_release_ctxt() which is given an xprt and a ctxt, which may have been taken either from an rqst or from a dreq. The caller is now responsible for clearing that pointer after the call to ->xpo_release_ctxt. We also clear dr->xprt_ctxt when the ctxt is moved into a new rqst when revisiting a deferred request. This ensures there is only one pointer to the ctxt, so the risk of double freeing in future is reduced. The new code in svc_xprt_release which releases both the ctxt and any rq_deferred depends on this. Fixes: 773f91b2cf3f ("SUNRPC: Fix NFSD's request deferral on RDMA transports") Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'net')
-rw-r--r--net/sunrpc/svc_xprt.c23
-rw-r--r--net/sunrpc/svcsock.c30
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_recvfrom.c11
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_transport.c2
4 files changed, 39 insertions, 27 deletions
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 5fd94f6bdc75..13a14897bc17 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -532,13 +532,23 @@ void svc_reserve(struct svc_rqst *rqstp, int space)
}
EXPORT_SYMBOL_GPL(svc_reserve);
+static void free_deferred(struct svc_xprt *xprt, struct svc_deferred_req *dr)
+{
+ if (!dr)
+ return;
+
+ xprt->xpt_ops->xpo_release_ctxt(xprt, dr->xprt_ctxt);
+ kfree(dr);
+}
+
static void svc_xprt_release(struct svc_rqst *rqstp)
{
struct svc_xprt *xprt = rqstp->rq_xprt;
- xprt->xpt_ops->xpo_release_rqst(rqstp);
+ xprt->xpt_ops->xpo_release_ctxt(xprt, rqstp->rq_xprt_ctxt);
+ rqstp->rq_xprt_ctxt = NULL;
- kfree(rqstp->rq_deferred);
+ free_deferred(xprt, rqstp->rq_deferred);
rqstp->rq_deferred = NULL;
svc_rqst_release_pages(rqstp);
@@ -1054,7 +1064,7 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
spin_unlock_bh(&serv->sv_lock);
while ((dr = svc_deferred_dequeue(xprt)) != NULL)
- kfree(dr);
+ free_deferred(xprt, dr);
call_xpt_users(xprt);
svc_xprt_put(xprt);
@@ -1176,8 +1186,8 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
spin_unlock(&xprt->xpt_lock);
trace_svc_defer_drop(dr);
+ free_deferred(xprt, dr);
svc_xprt_put(xprt);
- kfree(dr);
return;
}
dr->xprt = NULL;
@@ -1222,14 +1232,13 @@ static struct cache_deferred_req *svc_defer(struct cache_req *req)
dr->addrlen = rqstp->rq_addrlen;
dr->daddr = rqstp->rq_daddr;
dr->argslen = rqstp->rq_arg.len >> 2;
- dr->xprt_ctxt = rqstp->rq_xprt_ctxt;
/* back up head to the start of the buffer and copy */
skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
dr->argslen << 2);
}
- WARN_ON_ONCE(rqstp->rq_xprt_ctxt != dr->xprt_ctxt);
+ dr->xprt_ctxt = rqstp->rq_xprt_ctxt;
rqstp->rq_xprt_ctxt = NULL;
trace_svc_defer(rqstp);
svc_xprt_get(rqstp->rq_xprt);
@@ -1263,6 +1272,8 @@ static noinline int svc_deferred_recv(struct svc_rqst *rqstp)
rqstp->rq_daddr = dr->daddr;
rqstp->rq_respages = rqstp->rq_pages;
rqstp->rq_xprt_ctxt = dr->xprt_ctxt;
+
+ dr->xprt_ctxt = NULL;
svc_xprt_received(rqstp->rq_xprt);
return dr->argslen << 2;
}
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 9989194446a5..63fe7a338992 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -121,27 +121,27 @@ static void svc_reclassify_socket(struct socket *sock)
#endif
/**
- * svc_tcp_release_rqst - Release transport-related resources
- * @rqstp: request structure with resources to be released
+ * svc_tcp_release_ctxt - Release transport-related resources
+ * @xprt: the transport which owned the context
+ * @ctxt: the context from rqstp->rq_xprt_ctxt or dr->xprt_ctxt
*
*/
-static void svc_tcp_release_rqst(struct svc_rqst *rqstp)
+static void svc_tcp_release_ctxt(struct svc_xprt *xprt, void *ctxt)
{
}
/**
- * svc_udp_release_rqst - Release transport-related resources
- * @rqstp: request structure with resources to be released
+ * svc_udp_release_ctxt - Release transport-related resources
+ * @xprt: the transport which owned the context
+ * @ctxt: the context from rqstp->rq_xprt_ctxt or dr->xprt_ctxt
*
*/
-static void svc_udp_release_rqst(struct svc_rqst *rqstp)
+static void svc_udp_release_ctxt(struct svc_xprt *xprt, void *ctxt)
{
- struct sk_buff *skb = rqstp->rq_xprt_ctxt;
+ struct sk_buff *skb = ctxt;
- if (skb) {
- rqstp->rq_xprt_ctxt = NULL;
+ if (skb)
consume_skb(skb);
- }
}
union svc_pktinfo_u {
@@ -696,7 +696,8 @@ static int svc_udp_sendto(struct svc_rqst *rqstp)
unsigned int sent;
int err;
- svc_udp_release_rqst(rqstp);
+ svc_udp_release_ctxt(xprt, rqstp->rq_xprt_ctxt);
+ rqstp->rq_xprt_ctxt = NULL;
svc_set_cmsg_data(rqstp, cmh);
@@ -768,7 +769,7 @@ static const struct svc_xprt_ops svc_udp_ops = {
.xpo_recvfrom = svc_udp_recvfrom,
.xpo_sendto = svc_udp_sendto,
.xpo_result_payload = svc_sock_result_payload,
- .xpo_release_rqst = svc_udp_release_rqst,
+ .xpo_release_ctxt = svc_udp_release_ctxt,
.xpo_detach = svc_sock_detach,
.xpo_free = svc_sock_free,
.xpo_has_wspace = svc_udp_has_wspace,
@@ -1301,7 +1302,8 @@ static int svc_tcp_sendto(struct svc_rqst *rqstp)
unsigned int sent;
int err;
- svc_tcp_release_rqst(rqstp);
+ svc_tcp_release_ctxt(xprt, rqstp->rq_xprt_ctxt);
+ rqstp->rq_xprt_ctxt = NULL;
atomic_inc(&svsk->sk_sendqlen);
mutex_lock(&xprt->xpt_mutex);
@@ -1346,7 +1348,7 @@ static const struct svc_xprt_ops svc_tcp_ops = {
.xpo_recvfrom = svc_tcp_recvfrom,
.xpo_sendto = svc_tcp_sendto,
.xpo_result_payload = svc_sock_result_payload,
- .xpo_release_rqst = svc_tcp_release_rqst,
+ .xpo_release_ctxt = svc_tcp_release_ctxt,
.xpo_detach = svc_tcp_sock_detach,
.xpo_free = svc_sock_free,
.xpo_has_wspace = svc_tcp_has_wspace,
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 1c658fa43063..a22fe7587fa6 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -239,21 +239,20 @@ void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma,
}
/**
- * svc_rdma_release_rqst - Release transport-specific per-rqst resources
- * @rqstp: svc_rqst being released
+ * svc_rdma_release_ctxt - Release transport-specific per-rqst resources
+ * @xprt: the transport which owned the context
+ * @vctxt: the context from rqstp->rq_xprt_ctxt or dr->xprt_ctxt
*
* Ensure that the recv_ctxt is released whether or not a Reply
* was sent. For example, the client could close the connection,
* or svc_process could drop an RPC, before the Reply is sent.
*/
-void svc_rdma_release_rqst(struct svc_rqst *rqstp)
+void svc_rdma_release_ctxt(struct svc_xprt *xprt, void *vctxt)
{
- struct svc_rdma_recv_ctxt *ctxt = rqstp->rq_xprt_ctxt;
- struct svc_xprt *xprt = rqstp->rq_xprt;
+ struct svc_rdma_recv_ctxt *ctxt = vctxt;
struct svcxprt_rdma *rdma =
container_of(xprt, struct svcxprt_rdma, sc_xprt);
- rqstp->rq_xprt_ctxt = NULL;
if (ctxt)
svc_rdma_recv_ctxt_put(rdma, ctxt);
}
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 416b298f74dd..ca04f7a6a085 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -80,7 +80,7 @@ static const struct svc_xprt_ops svc_rdma_ops = {
.xpo_recvfrom = svc_rdma_recvfrom,
.xpo_sendto = svc_rdma_sendto,
.xpo_result_payload = svc_rdma_result_payload,
- .xpo_release_rqst = svc_rdma_release_rqst,
+ .xpo_release_ctxt = svc_rdma_release_ctxt,
.xpo_detach = svc_rdma_detach,
.xpo_free = svc_rdma_free,
.xpo_has_wspace = svc_rdma_has_wspace,