Add a per-transport maximum limit in the socket case, and add
helpers to allow the NFSv4 code to discover that limit.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 3 +++
include/linux/sunrpc/bc_xprt.h | 1 +
include/linux/sunrpc/clnt.h | 1 +
include/linux/sunrpc/xprt.h | 6 +++--
net/sunrpc/backchannel_rqst.c | 40 +++++++++++++++++--------------
net/sunrpc/clnt.c | 13 ++++++++++
net/sunrpc/svc.c | 2 +-
net/sunrpc/xprtrdma/backchannel.c | 7 ++++++
net/sunrpc/xprtrdma/transport.c | 1 +
net/sunrpc/xprtrdma/xprt_rdma.h | 1 +
net/sunrpc/xprtsock.c | 1 +
11 files changed, 55 insertions(+), 21 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 52de7245a2ee..39896afc6edf 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -8380,6 +8380,7 @@ static void nfs4_init_channel_attrs(struct nfs41_create_session_args *args,
{
unsigned int max_rqst_sz, max_resp_sz;
unsigned int max_bc_payload = rpc_max_bc_payload(clnt);
+ unsigned int max_bc_slots = rpc_num_bc_slots(clnt);
max_rqst_sz = NFS_MAX_FILE_IO_SIZE + nfs41_maxwrite_overhead;
max_resp_sz = NFS_MAX_FILE_IO_SIZE + nfs41_maxread_overhead;
@@ -8402,6 +8403,8 @@ static void nfs4_init_channel_attrs(struct nfs41_create_session_args *args,
args->bc_attrs.max_resp_sz_cached = 0;
args->bc_attrs.max_ops = NFS4_MAX_BACK_CHANNEL_OPS;
args->bc_attrs.max_reqs = max_t(unsigned short, max_session_cb_slots, 1);
+ if (args->bc_attrs.max_reqs > max_bc_slots)
+ args->bc_attrs.max_reqs = max_bc_slots;
dprintk("%s: Back Channel : max_rqst_sz=%u max_resp_sz=%u "
"max_resp_sz_cached=%u max_ops=%u max_reqs=%u\n",
diff --git a/include/linux/sunrpc/bc_xprt.h b/include/linux/sunrpc/bc_xprt.h
index d4229a78524a..87d27e13d885 100644
--- a/include/linux/sunrpc/bc_xprt.h
+++ b/include/linux/sunrpc/bc_xprt.h
@@ -43,6 +43,7 @@ void xprt_destroy_backchannel(struct rpc_xprt *, unsigned int max_reqs);
int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs);
void xprt_destroy_bc(struct rpc_xprt *xprt, unsigned int max_reqs);
void xprt_free_bc_rqst(struct rpc_rqst *req);
+unsigned int xprt_bc_max_slots(struct rpc_xprt *xprt);
/*
* Determine if a shared backchannel is in use
diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h
index 4e070e00c143..abc63bd1be2b 100644
--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -194,6 +194,7 @@ void rpc_setbufsize(struct rpc_clnt *, unsigned int, unsigned int);
struct net * rpc_net_ns(struct rpc_clnt *);
size_t rpc_max_payload(struct rpc_clnt *);
size_t rpc_max_bc_payload(struct rpc_clnt *);
+unsigned int rpc_num_bc_slots(struct rpc_clnt *);
void rpc_force_rebind(struct rpc_clnt *);
size_t rpc_peeraddr(struct rpc_clnt *, struct sockaddr *, size_t);
const char *rpc_peeraddr2str(struct rpc_clnt *, enum rpc_display_format_t);
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index ed76e5fb36c1..13e108bcc9eb 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -158,6 +158,7 @@ struct rpc_xprt_ops {
int (*bc_setup)(struct rpc_xprt *xprt,
unsigned int min_reqs);
size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
+ unsigned int (*bc_num_slots)(struct rpc_xprt *xprt);
void (*bc_free_rqst)(struct rpc_rqst *rqst);
void (*bc_destroy)(struct rpc_xprt *xprt,
unsigned int max_reqs);
@@ -251,8 +252,9 @@ struct rpc_xprt {
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
struct svc_serv *bc_serv; /* The RPC service which will */
/* process the callback */
- int bc_alloc_count; /* Total number of preallocs */
- atomic_t bc_free_slots;
+ unsigned int bc_alloc_max;
+ unsigned int bc_alloc_count; /* Total number of preallocs */
+ atomic_t bc_slot_count; /* Number of allocated slots */
spinlock_t bc_pa_lock; /* Protects the preallocated
* items */
struct list_head bc_pa_list; /* List of preallocated
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index c47d82622fd1..339e8c077c2d 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -31,25 +31,20 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#define RPCDBG_FACILITY RPCDBG_TRANS
#endif
+#define BC_MAX_SLOTS 64U
+
+unsigned int xprt_bc_max_slots(struct rpc_xprt *xprt)
+{
+ return BC_MAX_SLOTS;
+}
+
/*
* Helper routines that track the number of preallocation elements
* on the transport.
*/
static inline int xprt_need_to_requeue(struct rpc_xprt *xprt)
{
- return xprt->bc_alloc_count < atomic_read(&xprt->bc_free_slots);
-}
-
-static inline void xprt_inc_alloc_count(struct rpc_xprt *xprt, unsigned int n)
-{
- atomic_add(n, &xprt->bc_free_slots);
- xprt->bc_alloc_count += n;
-}
-
-static inline int xprt_dec_alloc_count(struct rpc_xprt *xprt, unsigned int n)
-{
- atomic_sub(n, &xprt->bc_free_slots);
- return xprt->bc_alloc_count -= n;
+ return xprt->bc_alloc_count < xprt->bc_alloc_max;
}
/*
@@ -145,6 +140,9 @@ int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
dprintk("RPC: setup backchannel transport\n");
+ if (min_reqs > BC_MAX_SLOTS)
+ min_reqs = BC_MAX_SLOTS;
+
/*
* We use a temporary list to keep track of the preallocated
* buffers. Once we're done building the list we splice it
@@ -172,7 +170,9 @@ int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
*/
spin_lock(&xprt->bc_pa_lock);
list_splice(&tmp_list, &xprt->bc_pa_list);
- xprt_inc_alloc_count(xprt, min_reqs);
+ xprt->bc_alloc_count += min_reqs;
+ xprt->bc_alloc_max += min_reqs;
+ atomic_add(min_reqs, &xprt->bc_slot_count);
spin_unlock(&xprt->bc_pa_lock);
dprintk("RPC: setup backchannel transport done\n");
@@ -220,11 +220,13 @@ void xprt_destroy_bc(struct rpc_xprt *xprt, unsigned int max_reqs)
goto out;
spin_lock_bh(&xprt->bc_pa_lock);
- xprt_dec_alloc_count(xprt, max_reqs);
+ xprt->bc_alloc_max -= max_reqs;
list_for_each_entry_safe(req, tmp, &xprt->bc_pa_list, rq_bc_pa_list) {
dprintk("RPC: req=%p\n", req);
list_del(&req->rq_bc_pa_list);
xprt_free_allocation(req);
+ xprt->bc_alloc_count--;
+ atomic_dec(&xprt->bc_slot_count);
if (--max_reqs == 0)
break;
}
@@ -241,13 +243,14 @@ static struct rpc_rqst *xprt_get_bc_request(struct rpc_xprt *xprt, __be32 xid,
struct rpc_rqst *req = NULL;
dprintk("RPC: allocate a backchannel request\n");
- if (atomic_read(&xprt->bc_free_slots) <= 0)
- goto not_found;
if (list_empty(&xprt->bc_pa_list)) {
if (!new)
goto not_found;
+ if (atomic_read(&xprt->bc_slot_count) >= BC_MAX_SLOTS)
+ goto not_found;
list_add_tail(&new->rq_bc_pa_list, &xprt->bc_pa_list);
xprt->bc_alloc_count++;
+ atomic_inc(&xprt->bc_slot_count);
}
req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst,
rq_bc_pa_list);
@@ -291,6 +294,7 @@ void xprt_free_bc_rqst(struct rpc_rqst *req)
if (xprt_need_to_requeue(xprt)) {
list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
xprt->bc_alloc_count++;
+ atomic_inc(&xprt->bc_slot_count);
req = NULL;
}
spin_unlock_bh(&xprt->bc_pa_lock);
@@ -357,7 +361,7 @@ void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
spin_lock(&xprt->bc_pa_lock);
list_del(&req->rq_bc_pa_list);
- xprt_dec_alloc_count(xprt, 1);
+ xprt->bc_alloc_count--;
spin_unlock(&xprt->bc_pa_lock);
req->rq_private_buf.len = copied;
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 383555d2b522..79c849391cb9 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1526,6 +1526,19 @@ size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
}
EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
+unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
+{
+ struct rpc_xprt *xprt;
+ unsigned int ret;
+
+ rcu_read_lock();
+ xprt = rcu_dereference(clnt->cl_xprt);
+ ret = xprt->ops->bc_num_slots(xprt);
+ rcu_read_unlock();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
+
/**
* rpc_force_rebind - force transport to check that remote port is unchanged
* @clnt: client to rebind
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index e15cb704453e..220b79988000 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1595,7 +1595,7 @@ bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
/* Parse and execute the bc call */
proc_error = svc_process_common(rqstp, argv, resv);
- atomic_inc(&req->rq_xprt->bc_free_slots);
+ atomic_dec(&req->rq_xprt->bc_slot_count);
if (!proc_error) {
/* Processing error: drop the request */
xprt_free_bc_request(req);
diff --git a/net/sunrpc/xprtrdma/backchannel.c b/net/sunrpc/xprtrdma/backchannel.c
index ce986591f213..59e624b1d7a0 100644
--- a/net/sunrpc/xprtrdma/backchannel.c
+++ b/net/sunrpc/xprtrdma/backchannel.c
@@ -52,6 +52,13 @@ size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *xprt)
return maxmsg - RPCRDMA_HDRLEN_MIN;
}
+unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *xprt)
+{
+ struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+
+ return r_xprt->rx_buf.rb_bc_srv_max_requests;
+}
+
static int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
{
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 4993aa49ecbe..52abddac19e5 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -812,6 +812,7 @@ static const struct rpc_xprt_ops xprt_rdma_procs = {
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
.bc_setup = xprt_rdma_bc_setup,
.bc_maxpayload = xprt_rdma_bc_maxpayload,
+ .bc_num_slots = xprt_rdma_bc_max_slots,
.bc_free_rqst = xprt_rdma_bc_free_rqst,
.bc_destroy = xprt_rdma_bc_destroy,
#endif
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 8378f45d2da7..92ce09fcea74 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -605,6 +605,7 @@ void xprt_rdma_cleanup(void);
#if defined(CONFIG_SUNRPC_BACKCHANNEL)
int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
+unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 3c2cc96afcaa..6b1fca51028a 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2788,6 +2788,7 @@ static const struct rpc_xprt_ops xs_tcp_ops = {
#ifdef CONFIG_SUNRPC_BACKCHANNEL
.bc_setup = xprt_setup_bc,
.bc_maxpayload = xs_tcp_bc_maxpayload,
+ .bc_num_slots = xprt_bc_max_slots,
.bc_free_rqst = xprt_free_bc_rqst,
.bc_destroy = xprt_destroy_bc,
#endif
--
2.21.0
