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-rw-r--r--drivers/vhost/scsi.c136
1 files changed, 103 insertions, 33 deletions
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 0c27c7d..4b79a1f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1,12 +1,12 @@
/*******************************************************************************
* Vhost kernel TCM fabric driver for virtio SCSI initiators
*
- * (C) Copyright 2010-2012 RisingTide Systems LLC.
+ * (C) Copyright 2010-2013 Datera, Inc.
* (C) Copyright 2010-2012 IBM Corp.
*
* Licensed to the Linux Foundation under the General Public License (GPL) version 2.
*
- * Authors: Nicholas A. Bellinger <nab@risingtidesystems.com>
+ * Authors: Nicholas A. Bellinger <nab@daterainc.com>
* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
@@ -48,12 +48,16 @@
#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
+#define TCM_VHOST_PREALLOC_SGLS 2048
+#define TCM_VHOST_PREALLOC_PAGES 2048
struct vhost_scsi_inflight {
/* Wait for the flush operation to finish */
@@ -79,6 +83,7 @@ struct tcm_vhost_cmd {
u32 tvc_lun;
/* Pointer to the SGL formatted memory from virtio-scsi */
struct scatterlist *tvc_sgl;
+ struct page **tvc_upages;
/* Pointer to response */
struct virtio_scsi_cmd_resp __user *tvc_resp;
/* Pointer to vhost_scsi for our device */
@@ -450,17 +455,16 @@ 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;
for (i = 0; i < tv_cmd->tvc_sgl_count; i++)
put_page(sg_page(&tv_cmd->tvc_sgl[i]));
-
- kfree(tv_cmd->tvc_sgl);
}
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 +708,7 @@ 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 +716,27 @@ vhost_scsi_allocate_cmd(struct vhost_virtqueue *vq,
{
struct tcm_vhost_cmd *cmd;
struct tcm_vhost_nexus *tv_nexus;
+ struct se_session *se_sess;
+ struct scatterlist *sg;
+ struct page **pages;
+ 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];
+ sg = cmd->tvc_sgl;
+ pages = cmd->tvc_upages;
+ memset(cmd, 0, sizeof(struct tcm_vhost_cmd));
+
+ cmd->tvc_sgl = sg;
+ cmd->tvc_upages = pages;
+ 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;
@@ -740,7 +753,8 @@ vhost_scsi_allocate_cmd(struct vhost_virtqueue *vq,
* Returns the number of scatterlist entries used or -errno on error.
*/
static int
-vhost_scsi_map_to_sgl(struct scatterlist *sgl,
+vhost_scsi_map_to_sgl(struct tcm_vhost_cmd *tv_cmd,
+ struct scatterlist *sgl,
unsigned int sgl_count,
struct iovec *iov,
int write)
@@ -752,13 +766,25 @@ vhost_scsi_map_to_sgl(struct scatterlist *sgl,
struct page **pages;
int ret, i;
+ if (sgl_count > TCM_VHOST_PREALLOC_SGLS) {
+ pr_err("vhost_scsi_map_to_sgl() psgl_count: %u greater than"
+ " preallocated TCM_VHOST_PREALLOC_SGLS: %u\n",
+ sgl_count, TCM_VHOST_PREALLOC_SGLS);
+ return -ENOBUFS;
+ }
+
pages_nr = iov_num_pages(iov);
if (pages_nr > sgl_count)
return -ENOBUFS;
- pages = kmalloc(pages_nr * sizeof(struct page *), GFP_KERNEL);
- if (!pages)
- return -ENOMEM;
+ if (pages_nr > TCM_VHOST_PREALLOC_PAGES) {
+ pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"
+ " preallocated TCM_VHOST_PREALLOC_PAGES: %u\n",
+ pages_nr, TCM_VHOST_PREALLOC_PAGES);
+ return -ENOBUFS;
+ }
+
+ pages = tv_cmd->tvc_upages;
ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);
/* No pages were pinned */
@@ -783,7 +809,6 @@ vhost_scsi_map_to_sgl(struct scatterlist *sgl,
}
out:
- kfree(pages);
return ret;
}
@@ -807,24 +832,20 @@ vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd,
/* TODO overflow checking */
- sg = kmalloc(sizeof(cmd->tvc_sgl[0]) * sgl_count, GFP_ATOMIC);
- if (!sg)
- return -ENOMEM;
- pr_debug("%s sg %p sgl_count %u is_err %d\n", __func__,
- sg, sgl_count, !sg);
+ sg = cmd->tvc_sgl;
+ pr_debug("%s sg %p sgl_count %u\n", __func__, sg, sgl_count);
sg_init_table(sg, sgl_count);
- cmd->tvc_sgl = sg;
cmd->tvc_sgl_count = sgl_count;
pr_debug("Mapping %u iovecs for %u pages\n", niov, sgl_count);
for (i = 0; i < niov; i++) {
- ret = vhost_scsi_map_to_sgl(sg, sgl_count, &iov[i], write);
+ ret = vhost_scsi_map_to_sgl(cmd, sg, sgl_count, &iov[i],
+ write);
if (ret < 0) {
for (i = 0; i < cmd->tvc_sgl_count; i++)
put_page(sg_page(&cmd->tvc_sgl[i]));
- kfree(cmd->tvc_sgl);
- cmd->tvc_sgl = NULL;
+
cmd->tvc_sgl_count = 0;
return ret;
}
@@ -989,10 +1010,10 @@ 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;
}
@@ -1654,11 +1675,31 @@ static void tcm_vhost_drop_nodeacl(struct se_node_acl *se_acl)
kfree(nacl);
}
+static void tcm_vhost_free_cmd_map_res(struct tcm_vhost_nexus *nexus,
+ struct se_session *se_sess)
+{
+ struct tcm_vhost_cmd *tv_cmd;
+ unsigned int i;
+
+ if (!se_sess->sess_cmd_map)
+ return;
+
+ for (i = 0; i < TCM_VHOST_DEFAULT_TAGS; i++) {
+ tv_cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[i];
+
+ kfree(tv_cmd->tvc_sgl);
+ kfree(tv_cmd->tvc_upages);
+ }
+}
+
static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,
const char *name)
{
struct se_portal_group *se_tpg;
+ struct se_session *se_sess;
struct tcm_vhost_nexus *tv_nexus;
+ struct tcm_vhost_cmd *tv_cmd;
+ unsigned int i;
mutex_lock(&tpg->tv_tpg_mutex);
if (tpg->tpg_nexus) {
@@ -1675,14 +1716,37 @@ 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);
return -ENOMEM;
}
+ se_sess = tv_nexus->tvn_se_sess;
+ for (i = 0; i < TCM_VHOST_DEFAULT_TAGS; i++) {
+ tv_cmd = &((struct tcm_vhost_cmd *)se_sess->sess_cmd_map)[i];
+
+ tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *
+ TCM_VHOST_PREALLOC_SGLS, GFP_KERNEL);
+ if (!tv_cmd->tvc_sgl) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
+ goto out;
+ }
+
+ tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *
+ TCM_VHOST_PREALLOC_PAGES, GFP_KERNEL);
+ if (!tv_cmd->tvc_upages) {
+ mutex_unlock(&tpg->tv_tpg_mutex);
+ pr_err("Unable to allocate tv_cmd->tvc_upages\n");
+ goto out;
+ }
+ }
/*
* Since we are running in 'demo mode' this call with generate a
* struct se_node_acl for the tcm_vhost struct se_portal_group with
@@ -1694,9 +1758,7 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,
mutex_unlock(&tpg->tv_tpg_mutex);
pr_debug("core_tpg_check_initiator_node_acl() failed"
" for %s\n", name);
- transport_free_session(tv_nexus->tvn_se_sess);
- kfree(tv_nexus);
- return -ENOMEM;
+ goto out;
}
/*
* Now register the TCM vhost virtual I_T Nexus as active with the
@@ -1708,6 +1770,12 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,
mutex_unlock(&tpg->tv_tpg_mutex);
return 0;
+
+out:
+ tcm_vhost_free_cmd_map_res(tv_nexus, se_sess);
+ transport_free_session(se_sess);
+ kfree(tv_nexus);
+ return -ENOMEM;
}
static int tcm_vhost_drop_nexus(struct tcm_vhost_tpg *tpg)
@@ -1747,6 +1815,8 @@ static int tcm_vhost_drop_nexus(struct tcm_vhost_tpg *tpg)
pr_debug("TCM_vhost_ConfigFS: Removing I_T Nexus to emulated"
" %s Initiator Port: %s\n", tcm_vhost_dump_proto_id(tpg->tport),
tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
+
+ tcm_vhost_free_cmd_map_res(tv_nexus, se_sess);
/*
* Release the SCSI I_T Nexus to the emulated vhost Target Port
*/
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