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

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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: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2013-06-07 17:47:46 -07:00
parent c0add7fd05
commit 4824d3bfb9
1 changed files with 21 additions and 12 deletions
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33
drivers/vhost/scsi.c
View file

@ -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,
exp_data_len, data_direction);
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);