scsi: target: Remove se_dev_entry.ua_count

se_dev_entry.ua_count is only used to check whether or not
se_dev_entry.ua_list is empty. Use list_empty_careful() instead.  Checking
whether or not ua_list is empty without holding the lock that protects that
list is fine because the code that dequeues from that list will check again
whether or not that list is empty.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bart Van Assche 2018-06-22 14:53:07 -07:00 committed by Martin K. Petersen
parent 325c1e8b24
commit e936a38ac9
3 changed files with 2 additions and 12 deletions

View File

@ -336,7 +336,6 @@ int core_enable_device_list_for_node(
return -ENOMEM;
}
atomic_set(&new->ua_count, 0);
spin_lock_init(&new->ua_lock);
INIT_LIST_HEAD(&new->ua_list);
INIT_LIST_HEAD(&new->lun_link);

View File

@ -55,7 +55,7 @@ target_scsi3_ua_check(struct se_cmd *cmd)
rcu_read_unlock();
return 0;
}
if (!atomic_read(&deve->ua_count)) {
if (list_empty_careful(&deve->ua_list)) {
rcu_read_unlock();
return 0;
}
@ -154,7 +154,6 @@ int core_scsi3_ua_allocate(
&deve->ua_list);
spin_unlock(&deve->ua_lock);
atomic_inc_mb(&deve->ua_count);
return 0;
}
list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
@ -164,7 +163,6 @@ int core_scsi3_ua_allocate(
" 0x%02x, ASCQ: 0x%02x\n", deve->mapped_lun,
asc, ascq);
atomic_inc_mb(&deve->ua_count);
return 0;
}
@ -196,8 +194,6 @@ void core_scsi3_ua_release_all(
list_for_each_entry_safe(ua, ua_p, &deve->ua_list, ua_nacl_list) {
list_del(&ua->ua_nacl_list);
kmem_cache_free(se_ua_cache, ua);
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
}
@ -263,8 +259,6 @@ bool core_scsi3_ua_for_check_condition(struct se_cmd *cmd, u8 *key, u8 *asc,
}
list_del(&ua->ua_nacl_list);
kmem_cache_free(se_ua_cache, ua);
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
rcu_read_unlock();
@ -304,7 +298,7 @@ int core_scsi3_ua_clear_for_request_sense(
rcu_read_unlock();
return -EINVAL;
}
if (!atomic_read(&deve->ua_count)) {
if (list_empty_careful(&deve->ua_list)) {
rcu_read_unlock();
return -EPERM;
}
@ -327,8 +321,6 @@ int core_scsi3_ua_clear_for_request_sense(
}
list_del(&ua->ua_nacl_list);
kmem_cache_free(se_ua_cache, ua);
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
rcu_read_unlock();

View File

@ -638,7 +638,6 @@ struct se_dev_entry {
atomic_long_t total_cmds;
atomic_long_t read_bytes;
atomic_long_t write_bytes;
atomic_t ua_count;
/* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */
struct kref pr_kref;
struct completion pr_comp;