Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4824d3bf authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

vhost/scsi: Convert to per-cpu ida_alloc + ida_free command map 



This patch changes vhost/scsi to use transport_init_session_tags()
pre-allocation logic for per-cpu session tag pooling with internal
ida_alloc() + ida_free() calls based upon the saved se_cmd->map_tag id.

FIXME: Make transport_init_session_tags() number of tags setup
configurable per vring client setting via configfs

v5 changes:
 - Convert to percpu_ida.h include

v3 changes:
 - Update to percpu-ida usage
 - Rebase to v3.11-rc5 code

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Asias He <asias@redhat.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent c0add7fd

drivers/vhost/scsi.c

+21 −12
Original line number Diff line number Diff line
@@ -48,12 +48,14 @@ 
#include <linux/virtio_scsi.h>

#include <linux/llist.h>

#include <linux/bitmap.h>

#include <linux/percpu_ida.h>



#include "vhost.h"



#define TCM_VHOST_VERSION  "v0.1"

#define TCM_VHOST_NAMELEN 256

#define TCM_VHOST_MAX_CDB_SIZE 32

#define TCM_VHOST_DEFAULT_TAGS 256



struct vhost_scsi_inflight {

	/* Wait for the flush operation to finish */
@@ -450,6 +452,7 @@ static void tcm_vhost_release_cmd(struct se_cmd *se_cmd) 
{

	struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd,

				struct tcm_vhost_cmd, tvc_se_cmd);

	struct se_session *se_sess = se_cmd->se_sess;



	if (tv_cmd->tvc_sgl_count) {

		u32 i;
@@ -460,7 +463,7 @@ static void tcm_vhost_release_cmd(struct se_cmd *se_cmd) 
        }



	tcm_vhost_put_inflight(tv_cmd->inflight);

	kfree(tv_cmd);

	percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);

}



static int tcm_vhost_shutdown_session(struct se_session *se_sess)
@@ -704,7 +707,7 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) 
}



static struct tcm_vhost_cmd *

vhost_scsi_allocate_cmd(struct vhost_virtqueue *vq,

vhost_scsi_get_tag(struct vhost_virtqueue *vq,

			struct tcm_vhost_tpg *tpg,

			struct virtio_scsi_cmd_req *v_req,

			u32 exp_data_len,
@@ -712,18 +715,21 @@ vhost_scsi_allocate_cmd(struct vhost_virtqueue *vq, 
{

	struct tcm_vhost_cmd *cmd;

	struct tcm_vhost_nexus *tv_nexus;

	struct se_session *se_sess;

	int tag;



	tv_nexus = tpg->tpg_nexus;

	if (!tv_nexus) {

		pr_err("Unable to locate active struct tcm_vhost_nexus\n");

		return ERR_PTR(-EIO);

	}

	se_sess = tv_nexus->tvn_se_sess;



	cmd = kzalloc(sizeof(struct tcm_vhost_cmd), GFP_ATOMIC);

	if (!cmd) {

		pr_err("Unable to allocate struct tcm_vhost_cmd\n");

		return ERR_PTR(-ENOMEM);

	}

	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_KERNEL);

	cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[tag];

	memset(cmd, 0, sizeof(struct tcm_vhost_cmd));



	cmd->tvc_se_cmd.map_tag = tag;

	cmd->tvc_tag = v_req->tag;

	cmd->tvc_task_attr = v_req->task_attr;

	cmd->tvc_exp_data_len = exp_data_len;
@@ -989,10 +995,10 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) 
		for (i = 0; i < data_num; i++)

			exp_data_len += vq->iov[data_first + i].iov_len;



		cmd = vhost_scsi_allocate_cmd(vq, tpg, &v_req,

		cmd = vhost_scsi_get_tag(vq, tpg, &v_req,

					 exp_data_len, data_direction);

		if (IS_ERR(cmd)) {

			vq_err(vq, "vhost_scsi_allocate_cmd failed %ld\n",

			vq_err(vq, "vhost_scsi_get_tag failed %ld\n",

					PTR_ERR(cmd));

			goto err_cmd;

		}
@@ -1675,9 +1681,12 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg, 
		return -ENOMEM;

	}

	/*

	 *  Initialize the struct se_session pointer

	 *  Initialize the struct se_session pointer and setup tagpool

	 *  for struct tcm_vhost_cmd descriptors

	 */

	tv_nexus->tvn_se_sess = transport_init_session();

	tv_nexus->tvn_se_sess = transport_init_session_tags(

					TCM_VHOST_DEFAULT_TAGS,

					sizeof(struct tcm_vhost_cmd));

	if (IS_ERR(tv_nexus->tvn_se_sess)) {

		mutex_unlock(&tpg->tv_tpg_mutex);

		kfree(tv_nexus);