vhost/scsi: Add pre-allocation for tv_cmd SGL + upages memory (3aee26b4) · Commits · 戴 / test

drivers/vhost/scsi.c

+80 −19

Original line number	Diff line number	Diff line
		@@ -56,6 +56,8 @@
		#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 */
		@@ -81,6 +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 */
		@@ -458,8 +461,6 @@ static void tcm_vhost_release_cmd(struct se_cmd *se_cmd)
		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);
		@@ -716,6 +717,8 @@ vhost_scsi_get_tag(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;
		@@ -727,8 +730,12 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq,

		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;
		@@ -746,7 +753,8 @@ vhost_scsi_get_tag(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)
		@@ -758,13 +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 */
		@@ -789,7 +809,6 @@ vhost_scsi_map_to_sgl(struct scatterlist *sgl,
		}

		out:
		kfree(pages);
		return ret;
		}

		@@ -813,24 +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;
		}
		@@ -1660,11 +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) {
		@@ -1692,6 +1727,26 @@ static int tcm_vhost_make_nexus(struct tcm_vhost_tpg *tpg,
		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
		@@ -1703,9 +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
		@@ -1717,6 +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)
		@@ -1756,6 +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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