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>

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index e5c90afb40e676025d193374079752efbabe2838..73675eec740d698d3e48dd265fed262f82fc511d 100644 (file)
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -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);

diff --git a/drivers/target/target_core_ua.c b/drivers/target/target_core_ua.c
index 9399b38339f98d44b66392adde1bb5ac111a1f17..c8ac242ce888ecbc802b03a4c96464b21ec52568 100644 (file)
--- a/drivers/target/target_core_ua.c
+++ b/drivers/target/target_core_ua.c
@@ -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();

diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index ca59e065c1fd0465a76480d8cfcc586b913720fd..7a4ee7852ca486396b819c2cfb3334ce4756a997 100644 (file)
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -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;