ib_srpt: Convert to percpu_ida tag allocation

This patch converts ib_srpt to use existing percpu_ida tag
pre-allocation for struct srpt_send_ioctx.

This allows ib_srpt to drop it's internal pre-allocation
mechanisms with the extra spin_lock_irqsave, and use
percpu_ida common code for doing this.

Cc: Vu Pham <vu@mellanox.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 72a671e..b0707a7 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -1261,40 +1261,26 @@ free_mem:
  */
 static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
 {
+       struct se_session *se_sess;
        struct srpt_send_ioctx *ioctx;
-       unsigned long flags;
+       int tag;
 
        BUG_ON(!ch);
+       se_sess = ch->sess;
 
-       ioctx = NULL;
-       spin_lock_irqsave(&ch->spinlock, flags);
-       if (!list_empty(&ch->free_list)) {
-               ioctx = list_first_entry(&ch->free_list,
-                                        struct srpt_send_ioctx, free_list);
-               list_del(&ioctx->free_list);
+       tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+       if (tag < 0) {
+               pr_err("Unable to obtain tag for srpt_send_ioctx\n");
+               return NULL;
        }
-       spin_unlock_irqrestore(&ch->spinlock, flags);
-
-       if (!ioctx)
-               return ioctx;
-
-       BUG_ON(ioctx->ch != ch);
+       ioctx = &((struct srpt_send_ioctx *)se_sess->sess_cmd_map)[tag];
+       memset(ioctx, 0, sizeof(struct srpt_send_ioctx));
+       ioctx->ch = ch;
        spin_lock_init(&ioctx->spinlock);
        ioctx->state = SRPT_STATE_NEW;
-       ioctx->n_rbuf = 0;
-       ioctx->rbufs = NULL;
-       ioctx->n_rdma = 0;
-       ioctx->n_rdma_wrs = 0;
-       ioctx->rdma_wrs = NULL;
-       ioctx->mapped_sg_count = 0;
        init_completion(&ioctx->tx_done);
-       ioctx->queue_status_only = false;
-       /*
-        * transport_init_se_cmd() does not initialize all fields, so do it
-        * here.
-        */
-       memset(&ioctx->cmd, 0, sizeof(ioctx->cmd));
-       memset(&ioctx->sense_data, 0, sizeof(ioctx->sense_data));
+
+       ioctx->cmd.map_tag = tag;
 
        return ioctx;
 }
@@ -2241,7 +2227,7 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
        struct ib_cm_rep_param *rep_param;
        struct srpt_rdma_ch *ch, *tmp_ch;
        u32 it_iu_len;
-       int i, ret = 0;
+       int ret = 0;
        unsigned char *p;
 
        WARN_ON_ONCE(irqs_disabled());
@@ -2370,12 +2356,6 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
        if (!ch->ioctx_ring)
                goto free_ch;
 
-       INIT_LIST_HEAD(&ch->free_list);
-       for (i = 0; i < ch->rq_size; i++) {
-               ch->ioctx_ring[i]->ch = ch;
-               list_add_tail(&ch->ioctx_ring[i]->free_list, &ch->free_list);
-       }
-
        ret = srpt_create_ch_ib(ch);
        if (ret) {
                rej->reason = cpu_to_be32(
@@ -2406,7 +2386,8 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
        p = &ch->sess_name[0];
 
 try_again:
-       ch->sess = target_alloc_session(&sport->port_tpg_1, 0, 0,
+       ch->sess = target_alloc_session(&sport->port_tpg_1, ch->rq_size,
+                                       sizeof(struct srpt_send_ioctx),
                                        TARGET_PROT_NORMAL, p, ch, NULL);
        if (IS_ERR(ch->sess)) {
                pr_info("Rejected login because no ACL has been"
@@ -3194,7 +3175,7 @@ static void srpt_release_cmd(struct se_cmd *se_cmd)
        struct srpt_send_ioctx *ioctx = container_of(se_cmd,
                                struct srpt_send_ioctx, cmd);
        struct srpt_rdma_ch *ch = ioctx->ch;
-       unsigned long flags;
+       struct se_session *se_sess = ch->sess;
 
        WARN_ON(ioctx->state != SRPT_STATE_DONE);
        WARN_ON(ioctx->mapped_sg_count != 0);
@@ -3205,9 +3186,7 @@ static void srpt_release_cmd(struct se_cmd *se_cmd)
                ioctx->n_rbuf = 0;
        }
 
-       spin_lock_irqsave(&ch->spinlock, flags);
-       list_add(&ioctx->free_list, &ch->free_list);
-       spin_unlock_irqrestore(&ch->spinlock, flags);
+       percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);
 }
 
 /**

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.h b/drivers/infiniband/ulp/srpt/ib_srpt.h
index 09037f2..6fbb6e7 100644 (file)
--- a/drivers/infiniband/ulp/srpt/ib_srpt.h
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.h
@@ -179,7 +179,6 @@ struct srpt_recv_ioctx {
  * struct srpt_send_ioctx - SRPT send I/O context.
  * @ioctx:       See above.
  * @ch:          Channel pointer.
- * @free_list:   Node in srpt_rdma_ch.free_list.
  * @n_rbuf:      Number of data buffers in the received SRP command.
  * @rbufs:       Pointer to SRP data buffer array.
  * @single_rbuf: SRP data buffer if the command has only a single buffer.
@@ -202,7 +201,6 @@ struct srpt_send_ioctx {
        struct srp_direct_buf   *rbufs;
        struct srp_direct_buf   single_rbuf;
        struct scatterlist      *sg;
-       struct list_head        free_list;
        spinlock_t              spinlock;
        enum srpt_command_state state;
        struct se_cmd           cmd;