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Commit c0add7fd authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Add transport_init_session_tags using per-cpu ida 



This patch adds lib/idr.c based transport_init_session_tags() logic
that allows fabric drivers to setup a per-cpu se_sess->sess_tag_pool
and associated se_sess->sess_cmd_map for basic tagged pre-allocation
of fabric descriptor sized memory.

v5 changes:
  - Convert to percpu_ida.h include

v4 changes:
  - Add transport_alloc_session_tags() for fabrics that need early
    transport_init_session()

v3 changes:
  - Update to percpu-ida usage

Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Asias He <asias@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarAsias He <asias@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 798ab48e

drivers/target/target_core_transport.c

+48 −0
Original line number Diff line number Diff line
@@ -232,6 +232,50 @@ struct se_session *transport_init_session(void) 
}

EXPORT_SYMBOL(transport_init_session);



int transport_alloc_session_tags(struct se_session *se_sess,

			         unsigned int tag_num, unsigned int tag_size)

{

	int rc;



	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size, GFP_KERNEL);

	if (!se_sess->sess_cmd_map) {

		pr_err("Unable to allocate se_sess->sess_cmd_map\n");

		return -ENOMEM;

	}



	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);

	if (rc < 0) {

		pr_err("Unable to init se_sess->sess_tag_pool,"

			" tag_num: %u\n", tag_num);

		kfree(se_sess->sess_cmd_map);

		se_sess->sess_cmd_map = NULL;

		return -ENOMEM;

	}



	return 0;

}

EXPORT_SYMBOL(transport_alloc_session_tags);



struct se_session *transport_init_session_tags(unsigned int tag_num,

					       unsigned int tag_size)

{

	struct se_session *se_sess;

	int rc;



	se_sess = transport_init_session();

	if (IS_ERR(se_sess))

		return se_sess;



	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);

	if (rc < 0) {

		transport_free_session(se_sess);

		return ERR_PTR(-ENOMEM);

	}



	return se_sess;

}

EXPORT_SYMBOL(transport_init_session_tags);



/*

 * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.

 */
@@ -367,6 +411,10 @@ EXPORT_SYMBOL(transport_deregister_session_configfs); 


void transport_free_session(struct se_session *se_sess)

{

	if (se_sess->sess_cmd_map) {

		percpu_ida_destroy(&se_sess->sess_tag_pool);

		kfree(se_sess->sess_cmd_map);

	}

	kmem_cache_free(se_sess_cache, se_sess);

}

EXPORT_SYMBOL(transport_free_session);

include/target/target_core_base.h

+5 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/configfs.h>

#include <linux/dma-mapping.h>

#include <linux/blkdev.h>

#include <linux/percpu_ida.h>

#include <scsi/scsi_cmnd.h>

#include <net/sock.h>

#include <net/tcp.h>
@@ -415,6 +416,8 @@ struct se_cmd { 
	enum dma_data_direction	data_direction;

	/* For SAM Task Attribute */

	int			sam_task_attr;

	/* Used for se_sess->sess_tag_pool */

	unsigned int		map_tag;

	/* Transport protocol dependent state, see transport_state_table */

	enum transport_state_table t_state;

	unsigned		cmd_wait_set:1;
@@ -536,6 +539,8 @@ struct se_session { 
	struct list_head	sess_wait_list;

	spinlock_t		sess_cmd_lock;

	struct kref		sess_kref;

	void			*sess_cmd_map;

	struct percpu_ida	sess_tag_pool;

};



struct se_device;

include/target/target_core_fabric.h

+3 −0
Original line number Diff line number Diff line
@@ -84,6 +84,9 @@ struct target_core_fabric_ops { 
};



struct se_session *transport_init_session(void);

int transport_alloc_session_tags(struct se_session *, unsigned int,

		unsigned int);

struct se_session *transport_init_session_tags(unsigned int, unsigned int);

void	__transport_register_session(struct se_portal_group *,

		struct se_node_acl *, struct se_session *, void *);

void	transport_register_session(struct se_portal_group *,