diff options
| -rw-r--r-- | include/linux/sunrpc/xprt.h | 3 | ||||
| -rw-r--r-- | net/sunrpc/backchannel_rqst.c | 37 | ||||
| -rw-r--r-- | net/sunrpc/svc.c | 6 |
3 files changed, 31 insertions, 15 deletions
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 8b93ef5..bc9c39d 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -212,7 +212,8 @@ struct rpc_xprt { #if defined(CONFIG_SUNRPC_BACKCHANNEL) struct svc_serv *bc_serv; /* The RPC service which will */ /* process the callback */ - unsigned int bc_alloc_count; /* Total number of preallocs */ + int bc_alloc_count; /* Total number of preallocs */ + atomic_t bc_free_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 1baa410..9825ff0 100644 --- a/net/sunrpc/backchannel_rqst.c +++ b/net/sunrpc/backchannel_rqst.c @@ -37,16 +37,18 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ static inline int xprt_need_to_requeue(struct rpc_xprt *xprt) { - return xprt->bc_alloc_count > 0; + 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; } @@ -232,9 +234,15 @@ static struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt, __be32 xid) struct rpc_rqst *req = NULL; dprintk("RPC: allocate a backchannel request\n"); - if (list_empty(&xprt->bc_pa_list)) + if (atomic_read(&xprt->bc_free_slots) <= 0) goto not_found; - + if (list_empty(&xprt->bc_pa_list)) { + req = xprt_alloc_bc_req(xprt, GFP_ATOMIC); + if (!req) + goto not_found; + /* Note: this 'free' request adds it to xprt->bc_pa_list */ + xprt_free_bc_request(req); + } req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst, rq_bc_pa_list); req->rq_reply_bytes_recvd = 0; @@ -260,11 +268,21 @@ void xprt_free_bc_request(struct rpc_rqst *req) req->rq_connect_cookie = xprt->connect_cookie - 1; smp_mb__before_atomic(); - WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state)); clear_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); smp_mb__after_atomic(); - if (!xprt_need_to_requeue(xprt)) { + /* + * Return it to the list of preallocations so that it + * may be reused by a new callback request. + */ + spin_lock_bh(&xprt->bc_pa_lock); + if (xprt_need_to_requeue(xprt)) { + list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list); + xprt->bc_alloc_count++; + req = NULL; + } + spin_unlock_bh(&xprt->bc_pa_lock); + if (req != NULL) { /* * The last remaining session was destroyed while this * entry was in use. Free the entry and don't attempt @@ -275,14 +293,6 @@ void xprt_free_bc_request(struct rpc_rqst *req) xprt_free_allocation(req); return; } - - /* - * Return it to the list of preallocations so that it - * may be reused by a new callback request. - */ - spin_lock_bh(&xprt->bc_pa_lock); - list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list); - spin_unlock_bh(&xprt->bc_pa_lock); } /* @@ -326,6 +336,7 @@ 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->bc_alloc_count--; spin_unlock(&xprt->bc_pa_lock); req->rq_private_buf.len = copied; diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index 51c8cad..b47f02f 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c @@ -1351,6 +1351,7 @@ bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req, struct kvec *argv = &rqstp->rq_arg.head[0]; struct kvec *resv = &rqstp->rq_res.head[0]; struct rpc_task *task; + int proc_error; int error; dprintk("svc: %s(%p)\n", __func__, req); @@ -1382,7 +1383,10 @@ bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req, svc_getnl(argv); /* CALLDIR */ /* Parse and execute the bc call */ - if (!svc_process_common(rqstp, argv, resv)) { + proc_error = svc_process_common(rqstp, argv, resv); + + atomic_inc(&req->rq_xprt->bc_free_slots); + if (!proc_error) { /* Processing error: drop the request */ xprt_free_bc_request(req); return 0; |