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Diffstat (limited to 'net/sunrpc/backchannel_rqst.c')
-rw-r--r--net/sunrpc/backchannel_rqst.c144
1 files changed, 75 insertions, 69 deletions
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index ac701c28f44f..caa94cf57123 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
(c) 2007 Network Appliance, Inc. All Rights Reserved.
(c) 2009 NetApp. All Rights Reserved.
-NetApp provides this source code under the GPL v2 License.
-The GPL v2 license is available at
-http://opensource.org/licenses/gpl-license.php.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
-CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
-EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
-PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
-LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
******************************************************************************/
@@ -31,25 +17,20 @@ 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;
}
/*
@@ -69,6 +50,17 @@ static void xprt_free_allocation(struct rpc_rqst *req)
kfree(req);
}
+static void xprt_bc_reinit_xdr_buf(struct xdr_buf *buf)
+{
+ buf->head[0].iov_len = PAGE_SIZE;
+ buf->tail[0].iov_len = 0;
+ buf->pages = NULL;
+ buf->page_len = 0;
+ buf->flags = 0;
+ buf->len = 0;
+ buf->buflen = PAGE_SIZE;
+}
+
static int xprt_alloc_xdr_buf(struct xdr_buf *buf, gfp_t gfp_flags)
{
struct page *page;
@@ -80,9 +72,9 @@ static int xprt_alloc_xdr_buf(struct xdr_buf *buf, gfp_t gfp_flags)
return 0;
}
-static
-struct rpc_rqst *xprt_alloc_bc_req(struct rpc_xprt *xprt, gfp_t gfp_flags)
+static struct rpc_rqst *xprt_alloc_bc_req(struct rpc_xprt *xprt)
{
+ gfp_t gfp_flags = GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN;
struct rpc_rqst *req;
/* Pre-allocate one backchannel rpc_rqst */
@@ -91,8 +83,6 @@ struct rpc_rqst *xprt_alloc_bc_req(struct rpc_xprt *xprt, gfp_t gfp_flags)
return NULL;
req->rq_xprt = xprt;
- INIT_LIST_HEAD(&req->rq_list);
- INIT_LIST_HEAD(&req->rq_bc_list);
/* Preallocate one XDR receive buffer */
if (xprt_alloc_xdr_buf(&req->rq_rcv_buf, gfp_flags) < 0) {
@@ -117,7 +107,7 @@ out_free:
* by the backchannel. This function can be called multiple times
* when creating new sessions that use the same rpc_xprt. The
* preallocated buffers are added to the pool of resources used by
- * the rpc_xprt. Anyone of these resources may be used used by an
+ * the rpc_xprt. Any one of these resources may be used by an
* incoming callback request. It's up to the higher levels in the
* stack to enforce that the maximum number of session slots is not
* being exceeded.
@@ -146,6 +136,9 @@ 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
@@ -157,7 +150,7 @@ int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
INIT_LIST_HEAD(&tmp_list);
for (i = 0; i < min_reqs; i++) {
/* Pre-allocate one backchannel rpc_rqst */
- req = xprt_alloc_bc_req(xprt, GFP_KERNEL);
+ req = xprt_alloc_bc_req(xprt);
if (req == NULL) {
printk(KERN_ERR "Failed to create bc rpc_rqst\n");
goto out_free;
@@ -171,10 +164,12 @@ int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
/*
* Add the temporary list to the backchannel preallocation list
*/
- spin_lock_bh(&xprt->bc_pa_lock);
+ spin_lock(&xprt->bc_pa_lock);
list_splice(&tmp_list, &xprt->bc_pa_list);
- xprt_inc_alloc_count(xprt, min_reqs);
- spin_unlock_bh(&xprt->bc_pa_lock);
+ 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");
return 0;
@@ -198,7 +193,7 @@ out_free:
/**
* xprt_destroy_backchannel - Destroys the backchannel preallocated structures.
* @xprt: the transport holding the preallocated strucures
- * @max_reqs the maximum number of preallocated structures to destroy
+ * @max_reqs: the maximum number of preallocated structures to destroy
*
* Since these structures may have been allocated by multiple calls
* to xprt_setup_backchannel, we only destroy up to the maximum number
@@ -221,11 +216,13 @@ 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 -= min(max_reqs, xprt->bc_alloc_max);
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;
}
@@ -236,30 +233,30 @@ out:
list_empty(&xprt->bc_pa_list) ? "true" : "false");
}
-static struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt, __be32 xid)
+static struct rpc_rqst *xprt_get_bc_request(struct rpc_xprt *xprt, __be32 xid,
+ struct rpc_rqst *new)
{
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)) {
- req = xprt_alloc_bc_req(xprt, GFP_ATOMIC);
- if (!req)
+ if (!new)
goto not_found;
- list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list);
+ 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);
req->rq_reply_bytes_recvd = 0;
- req->rq_bytes_sent = 0;
memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
sizeof(req->rq_private_buf));
req->rq_xid = xid;
req->rq_connect_cookie = xprt->connect_cookie;
-not_found:
dprintk("RPC: backchannel req=%p\n", req);
+not_found:
return req;
}
@@ -291,8 +288,12 @@ void xprt_free_bc_rqst(struct rpc_rqst *req)
*/
spin_lock_bh(&xprt->bc_pa_lock);
if (xprt_need_to_requeue(xprt)) {
+ xprt_bc_reinit_xdr_buf(&req->rq_snd_buf);
+ xprt_bc_reinit_xdr_buf(&req->rq_rcv_buf);
+ req->rq_rcv_buf.len = PAGE_SIZE;
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);
@@ -305,8 +306,8 @@ void xprt_free_bc_rqst(struct rpc_rqst *req)
*/
dprintk("RPC: Last session removed req=%p\n", req);
xprt_free_allocation(req);
- return;
}
+ xprt_put(xprt);
}
/*
@@ -322,26 +323,33 @@ void xprt_free_bc_rqst(struct rpc_rqst *req)
*/
struct rpc_rqst *xprt_lookup_bc_request(struct rpc_xprt *xprt, __be32 xid)
{
- struct rpc_rqst *req;
-
- spin_lock(&xprt->bc_pa_lock);
- list_for_each_entry(req, &xprt->bc_pa_list, rq_bc_pa_list) {
- if (req->rq_connect_cookie != xprt->connect_cookie)
- continue;
- if (req->rq_xid == xid)
- goto found;
- }
- req = xprt_alloc_bc_request(xprt, xid);
+ struct rpc_rqst *req, *new = NULL;
+
+ do {
+ spin_lock(&xprt->bc_pa_lock);
+ list_for_each_entry(req, &xprt->bc_pa_list, rq_bc_pa_list) {
+ if (req->rq_connect_cookie != xprt->connect_cookie)
+ continue;
+ if (req->rq_xid == xid)
+ goto found;
+ }
+ req = xprt_get_bc_request(xprt, xid, new);
found:
- spin_unlock(&xprt->bc_pa_lock);
+ spin_unlock(&xprt->bc_pa_lock);
+ if (new) {
+ if (req != new)
+ xprt_free_allocation(new);
+ break;
+ } else if (req)
+ break;
+ new = xprt_alloc_bc_req(xprt);
+ } while (new);
return req;
}
/*
- * Add callback request to callback list. The callback
- * service sleeps on the sv_cb_waitq waiting for new
- * requests. Wake it up after adding enqueing the
- * request.
+ * Add callback request to callback list. Wake a thread
+ * on the first pool (usually the only pool) to handle it.
*/
void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
{
@@ -350,16 +358,14 @@ 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;
set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
dprintk("RPC: add callback request to list\n");
- spin_lock(&bc_serv->sv_cb_lock);
- list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
- wake_up(&bc_serv->sv_cb_waitq);
- spin_unlock(&bc_serv->sv_cb_lock);
+ xprt_get(xprt);
+ lwq_enqueue(&req->rq_bc_list, &bc_serv->sv_cb_list);
+ svc_pool_wake_idle_thread(&bc_serv->sv_pools[0]);
}
-
generated by cgit (git 2.34.1) at 2025-12-25 16:02:32 +0000