From: "Nicholas A. Bellinger" <nab@daterainc.com>
To: target-devel <target-devel@vger.kernel.org>
Cc: linux-scsi <linux-scsi@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>,
Sagi Grimberg <sagig@mellanox.com>,
Nicholas Bellinger <nab@linux-iscsi.org>
Subject: [PATCH 04/12] target: Convert UNIT_ATTENTION logic to RCU reader
Date: Tue, 12 May 2015 09:25:28 +0000 [thread overview]
Message-ID: <1431422736-29125-5-git-send-email-nab@daterainc.com> (raw)
In-Reply-To: <1431422736-29125-1-git-send-email-nab@daterainc.com>
From: Nicholas Bellinger <nab@linux-iscsi.org>
This patch converts target_core_ua.c code to use RCU read path locks
for se_node_acl->lun_entry_hlist access.
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
drivers/target/target_core_ua.c | 51 ++++++++++++++++++++++++++++-------------
1 file changed, 35 insertions(+), 16 deletions(-)
diff --git a/drivers/target/target_core_ua.c b/drivers/target/target_core_ua.c
index a0bf0d1..6c9616d 100644
--- a/drivers/target/target_core_ua.c
+++ b/drivers/target/target_core_ua.c
@@ -50,9 +50,17 @@ target_scsi3_ua_check(struct se_cmd *cmd)
if (!nacl)
return 0;
- deve = nacl->device_list[cmd->orig_fe_lun];
- if (!atomic_read(&deve->ua_count))
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
+ if (!deve) {
+ rcu_read_unlock();
return 0;
+ }
+ if (!atomic_read(&deve->ua_count)) {
+ rcu_read_unlock();
+ return 0;
+ }
+ rcu_read_unlock();
/*
* From sam4r14, section 5.14 Unit attention condition:
*
@@ -103,9 +111,12 @@ int core_scsi3_ua_allocate(
ua->ua_asc = asc;
ua->ua_ascq = ascq;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[unpacked_lun];
-
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, unpacked_lun);
+ if (!deve) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
spin_lock(&deve->ua_lock);
list_for_each_entry_safe(ua_p, ua_tmp, &deve->ua_list, ua_nacl_list) {
/*
@@ -113,7 +124,7 @@ int core_scsi3_ua_allocate(
*/
if ((ua_p->ua_asc == asc) && (ua_p->ua_ascq == ascq)) {
spin_unlock(&deve->ua_lock);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
kmem_cache_free(se_ua_cache, ua);
return 0;
}
@@ -158,14 +169,13 @@ int core_scsi3_ua_allocate(
list_add_tail(&ua->ua_nacl_list,
&deve->ua_list);
spin_unlock(&deve->ua_lock);
- spin_unlock_irq(&nacl->device_list_lock);
atomic_inc_mb(&deve->ua_count);
+ rcu_read_unlock();
return 0;
}
list_add_tail(&ua->ua_nacl_list, &deve->ua_list);
spin_unlock(&deve->ua_lock);
- spin_unlock_irq(&nacl->device_list_lock);
pr_debug("[%s]: Allocated UNIT ATTENTION, mapped LUN: %u, ASC:"
" 0x%02x, ASCQ: 0x%02x\n",
@@ -173,6 +183,7 @@ int core_scsi3_ua_allocate(
asc, ascq);
atomic_inc_mb(&deve->ua_count);
+ rcu_read_unlock();
return 0;
}
@@ -210,10 +221,14 @@ void core_scsi3_ua_for_check_condition(
if (!nacl)
return;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[cmd->orig_fe_lun];
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
+ if (!deve) {
+ rcu_read_unlock();
+ return;
+ }
if (!atomic_read(&deve->ua_count)) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return;
}
/*
@@ -249,7 +264,7 @@ void core_scsi3_ua_for_check_condition(
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
pr_debug("[%s]: %s UNIT ATTENTION condition with"
" INTLCK_CTRL: %d, mapped LUN: %u, got CDB: 0x%02x"
@@ -278,10 +293,14 @@ int core_scsi3_ua_clear_for_request_sense(
if (!nacl)
return -EINVAL;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[cmd->orig_fe_lun];
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun);
+ if (!deve) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
if (!atomic_read(&deve->ua_count)) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return -EPERM;
}
/*
@@ -307,7 +326,7 @@ int core_scsi3_ua_clear_for_request_sense(
atomic_dec_mb(&deve->ua_count);
}
spin_unlock(&deve->ua_lock);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
pr_debug("[%s]: Released UNIT ATTENTION condition, mapped"
" LUN: %u, got REQUEST_SENSE reported ASC: 0x%02x,"
--
1.9.1
next prev parent reply other threads:[~2015-05-12 9:36 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-12 9:25 [PATCH 00/12] target: TPG/NodeACL LUN table conversion to RCU hlist Nicholas A. Bellinger
2015-05-12 9:25 ` [PATCH 01/12] target: Convert se_node_acl->device_list[] " Nicholas A. Bellinger
2015-05-12 20:58 ` Andy Grover
2015-05-13 5:08 ` Nicholas A. Bellinger
2015-05-13 5:32 ` Christoph Hellwig
2015-05-13 5:41 ` Nicholas A. Bellinger
2015-05-13 5:46 ` Christoph Hellwig
2015-05-13 6:20 ` Nicholas A. Bellinger
2015-05-13 6:48 ` Christoph Hellwig
2015-05-13 6:35 ` Christoph Hellwig
2015-05-13 8:46 ` Nicholas A. Bellinger
2015-05-17 16:51 ` Christoph Hellwig
2015-05-18 7:17 ` Nicholas A. Bellinger
2015-05-18 7:41 ` Christoph Hellwig
2015-05-18 8:01 ` Christoph Hellwig
2015-05-19 6:05 ` Nicholas A. Bellinger
2015-05-19 6:22 ` Christoph Hellwig
2015-05-21 17:03 ` Christoph Hellwig
2015-05-21 18:10 ` Nicholas A. Bellinger
2015-05-12 9:25 ` [PATCH 02/12] target: Convert REPORT_LUN + MODE_SENSE to RCU reader Nicholas A. Bellinger
2015-05-13 5:47 ` Christoph Hellwig
2015-05-13 8:10 ` Nicholas A. Bellinger
2015-05-12 9:25 ` [PATCH 03/12] target/configfs: Convert mappedlun + SCSI MIBs " Nicholas A. Bellinger
2015-05-12 20:58 ` Andy Grover
2015-05-13 5:09 ` Nicholas A. Bellinger
2015-05-13 5:49 ` Christoph Hellwig
2015-05-12 9:25 ` Nicholas A. Bellinger [this message]
2015-05-12 9:25 ` [PATCH 05/12] target: Convert transport_lookup_*_lun " Nicholas A. Bellinger
2015-05-13 5:55 ` Christoph Hellwig
2015-05-13 7:42 ` Nicholas A. Bellinger
2015-05-12 9:25 ` [PATCH 06/12] target/pr: Convert se_dev_entry to kref for RCU Nicholas A. Bellinger
2015-05-13 5:59 ` Christoph Hellwig
2015-05-12 9:25 ` [PATCH 07/12] target/pr: Convert registration check to RCU pointer Nicholas A. Bellinger
2015-05-13 6:13 ` Christoph Hellwig
2015-05-12 9:25 ` [PATCH 08/12] target/pr: Change alloc_registration to avoid pr_reg_tg_pt_lun Nicholas A. Bellinger
2015-05-12 9:25 ` [PATCH 09/12] target: Convert se_portal_group->tpg_lun_list[] to RCU hlist Nicholas A. Bellinger
2015-05-13 6:24 ` Christoph Hellwig
2015-05-13 7:22 ` Juergen Gross
2015-05-13 7:53 ` Christoph Hellwig
2015-05-19 6:46 ` Christoph Hellwig
2015-05-12 9:25 ` [PATCH 10/12] target: Convert se_tpg->acl_node_lock to ->acl_node_mutex Nicholas A. Bellinger
2015-05-12 9:25 ` [PATCH 11/12] target: Convert core_tpg_deregister to use list splice Nicholas A. Bellinger
2015-05-12 9:25 ` [PATCH 12/12] target: Drop unused se_lun->lun_acl_list Nicholas A. Bellinger
2015-05-13 6:29 ` [PATCH 00/12] target: TPG/NodeACL LUN table conversion to RCU hlist Christoph Hellwig
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