From: Long Li <[email protected]> Create recevie buffers to handling SMBD response messages. Each SMBD response message is assocated with a receive buffer, where the message payload is received. The number of receive buffer is determine after negotiating SMBD transport with the server.
Signed-off-by: Long Li <[email protected]> --- fs/cifs/cifsrdma.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/cifs/cifsrdma.h | 3 ++ 2 files changed, 92 insertions(+) diff --git a/fs/cifs/cifsrdma.c b/fs/cifs/cifsrdma.c index 1636304..b3e43b1 100644 --- a/fs/cifs/cifsrdma.c +++ b/fs/cifs/cifsrdma.c @@ -54,6 +54,14 @@ #include "cifsrdma.h" +static struct cifs_rdma_response* get_receive_buffer( + struct cifs_rdma_info *info); +static void put_receive_buffer( + struct cifs_rdma_info *info, + struct cifs_rdma_response *response); +static int allocate_receive_buffers(struct cifs_rdma_info *info, int num_buf); +static void destroy_receive_buffers(struct cifs_rdma_info *info); + /* * Per RDMA transport connection parameters * as defined in [MS-SMBD] 3.1.1.1 @@ -280,6 +288,85 @@ static int cifs_rdma_ia_open( return rc; } +/* + * Receive buffer operations. + * For each remote send, we need to post a receive. The receive buffers are + * pre-allocated in advance. + */ +static struct cifs_rdma_response* get_receive_buffer(struct cifs_rdma_info *info) +{ + struct cifs_rdma_response *ret = NULL; + unsigned long flags; + + spin_lock_irqsave(&info->receive_queue_lock, flags); + if (!list_empty(&info->receive_queue)) { + ret = list_first_entry( + &info->receive_queue, + struct cifs_rdma_response, list); + list_del(&ret->list); + info->count_receive_buffer--; + info->count_get_receive_buffer++; + } + spin_unlock_irqrestore(&info->receive_queue_lock, flags); + + return ret; +} + +static void put_receive_buffer( + struct cifs_rdma_info *info, struct cifs_rdma_response *response) +{ + unsigned long flags; + + ib_dma_unmap_single(info->id->device, response->sge.addr, + response->sge.length, DMA_FROM_DEVICE); + + spin_lock_irqsave(&info->receive_queue_lock, flags); + list_add_tail(&response->list, &info->receive_queue); + info->count_receive_buffer++; + info->count_put_receive_buffer++; + spin_unlock_irqrestore(&info->receive_queue_lock, flags); +} + +static int allocate_receive_buffers(struct cifs_rdma_info *info, int num_buf) +{ + int i; + struct cifs_rdma_response *response; + + INIT_LIST_HEAD(&info->receive_queue); + spin_lock_init(&info->receive_queue_lock); + + for (i=0; i<num_buf; i++) { + response = mempool_alloc(info->response_mempool, GFP_KERNEL); + if (!response) + goto allocate_failed; + + response->info = info; + list_add_tail(&response->list, &info->receive_queue); + info->count_receive_buffer++; + } + + return 0; + +allocate_failed: + while (!list_empty(&info->receive_queue)) { + response = list_first_entry( + &info->receive_queue, + struct cifs_rdma_response, list); + list_del(&response->list); + info->count_receive_buffer--; + + mempool_free(response, info->response_mempool); + } + return -ENOMEM; +} + +static void destroy_receive_buffers(struct cifs_rdma_info *info) +{ + struct cifs_rdma_response *response; + while ((response = get_receive_buffer(info))) + mempool_free(response, info->response_mempool); +} + struct cifs_rdma_info* cifs_create_rdma_session( struct TCP_Server_Info *server, struct sockaddr *dstaddr) { @@ -383,6 +470,8 @@ struct cifs_rdma_info* cifs_create_rdma_session( info->response_mempool = mempool_create(info->receive_credit_max, mempool_alloc_slab, mempool_free_slab, info->response_cache); + + allocate_receive_buffers(info, info->receive_credit_max); out2: rdma_destroy_id(info->id); diff --git a/fs/cifs/cifsrdma.h b/fs/cifs/cifsrdma.h index 41ae61a..78ce2bf 100644 --- a/fs/cifs/cifsrdma.h +++ b/fs/cifs/cifsrdma.h @@ -59,6 +59,9 @@ struct cifs_rdma_info { atomic_t receive_credits; atomic_t receive_credit_target; + struct list_head receive_queue; + spinlock_t receive_queue_lock; + // response pool for RDMA receive struct kmem_cache *response_cache; mempool_t *response_mempool; -- 2.7.4
