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: Asias He <asias@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2013-06-07 17:38:58 -07:00
parent 798ab48eec
commit c0add7fd05
3 changed files with 56 additions and 0 deletions

View File

@ -232,6 +232,50 @@ struct se_session *transport_init_session(void)
} }
EXPORT_SYMBOL(transport_init_session); 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. * 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) 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); kmem_cache_free(se_sess_cache, se_sess);
} }
EXPORT_SYMBOL(transport_free_session); EXPORT_SYMBOL(transport_free_session);

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@ -5,6 +5,7 @@
#include <linux/configfs.h> #include <linux/configfs.h>
#include <linux/dma-mapping.h> #include <linux/dma-mapping.h>
#include <linux/blkdev.h> #include <linux/blkdev.h>
#include <linux/percpu_ida.h>
#include <scsi/scsi_cmnd.h> #include <scsi/scsi_cmnd.h>
#include <net/sock.h> #include <net/sock.h>
#include <net/tcp.h> #include <net/tcp.h>
@ -415,6 +416,8 @@ struct se_cmd {
enum dma_data_direction data_direction; enum dma_data_direction data_direction;
/* For SAM Task Attribute */ /* For SAM Task Attribute */
int sam_task_attr; int sam_task_attr;
/* Used for se_sess->sess_tag_pool */
unsigned int map_tag;
/* Transport protocol dependent state, see transport_state_table */ /* Transport protocol dependent state, see transport_state_table */
enum transport_state_table t_state; enum transport_state_table t_state;
unsigned cmd_wait_set:1; unsigned cmd_wait_set:1;
@ -536,6 +539,8 @@ struct se_session {
struct list_head sess_wait_list; struct list_head sess_wait_list;
spinlock_t sess_cmd_lock; spinlock_t sess_cmd_lock;
struct kref sess_kref; struct kref sess_kref;
void *sess_cmd_map;
struct percpu_ida sess_tag_pool;
}; };
struct se_device; struct se_device;

View File

@ -84,6 +84,9 @@ struct target_core_fabric_ops {
}; };
struct se_session *transport_init_session(void); 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 *, void __transport_register_session(struct se_portal_group *,
struct se_node_acl *, struct se_session *, void *); struct se_node_acl *, struct se_session *, void *);
void transport_register_session(struct se_portal_group *, void transport_register_session(struct se_portal_group *,