From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch converts various target_core_device.c to RCU reader path
to extract deve->mapped_lun before rcu_read_unlock() ahead of invoking
core_disable_device_list_for_node() to trigger subsequent RCU updater
code.
It includes core_free_device_list_for_node(), core_clear_lun_from_tpg(),
core_clear_initiator_node_from_tpg(), and core_update_device_list_access()
updates.
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_device.c | 52 +++++++++++++++++++------------------
drivers/target/target_core_tpg.c | 22 ++++++++--------
2 files changed, 38 insertions(+), 36 deletions(-)
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 9385e16..1053a2d 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -257,32 +257,33 @@ int core_free_device_list_for_node(
{
struct se_dev_entry *deve;
struct se_lun *lun;
- u32 i;
+ u32 i, mapped_lun;
- if (!nacl->device_list)
+ if (!nacl->lun_entry_hlist)
return 0;
- spin_lock_irq(&nacl->device_list_lock);
for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
- deve = nacl->device_list[i];
+ rcu_read_lock();
+ deve = rcu_dereference(nacl->lun_entry_hlist[i]);
- if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS))
+ if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS)) {
+ rcu_read_unlock();
continue;
-
+ }
if (!deve->se_lun) {
pr_err("%s device entries device pointer is"
" NULL, but Initiator has access.\n",
tpg->se_tpg_tfo->get_fabric_name());
+ rcu_read_unlock();
continue;
}
lun = deve->se_lun;
+ mapped_lun = deve->mapped_lun;
+ rcu_read_unlock();
- spin_unlock_irq(&nacl->device_list_lock);
- core_disable_device_list_for_node(lun, NULL, deve->mapped_lun,
- TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg);
- spin_lock_irq(&nacl->device_list_lock);
+ core_disable_device_list_for_node(lun, NULL, mapped_lun,
+ TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg);
}
- spin_unlock_irq(&nacl->device_list_lock);
array_free(nacl->lun_entry_hlist, TRANSPORT_MAX_LUNS_PER_TPG);
nacl->lun_entry_hlist = NULL;
@@ -297,8 +298,8 @@ void core_update_device_list_access(
{
struct se_dev_entry *deve;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[mapped_lun];
+ spin_lock_irq(&nacl->lun_entry_lock);
+ deve = rcu_dereference(nacl->lun_entry_hlist[mapped_lun]);
if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) {
deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY;
deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE;
@@ -306,7 +307,9 @@ void core_update_device_list_access(
deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE;
deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY;
}
- spin_unlock_irq(&nacl->device_list_lock);
+ spin_unlock_irq(&nacl->lun_entry_lock);
+
+ synchronize_rcu();
}
/* core_enable_device_list_for_node():
@@ -442,26 +445,25 @@ void core_clear_lun_from_tpg(struct se_lun *lun, struct se_portal_group *tpg)
{
struct se_node_acl *nacl;
struct se_dev_entry *deve;
- u32 i;
+ u32 i, mapped_lun;
spin_lock_irq(&tpg->acl_node_lock);
list_for_each_entry(nacl, &tpg->acl_node_list, acl_list) {
spin_unlock_irq(&tpg->acl_node_lock);
- spin_lock_irq(&nacl->device_list_lock);
for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
- deve = nacl->device_list[i];
- if (lun != deve->se_lun)
+ rcu_read_lock();
+ deve = rcu_dereference(nacl->lun_entry_hlist[i]);
+ if (!deve || lun != deve->se_lun) {
+ rcu_read_unlock();
continue;
- spin_unlock_irq(&nacl->device_list_lock);
-
- core_disable_device_list_for_node(lun, NULL,
- deve->mapped_lun, TRANSPORT_LUNFLAGS_NO_ACCESS,
- nacl, tpg);
+ }
+ mapped_lun = deve->mapped_lun;
+ rcu_read_unlock();
- spin_lock_irq(&nacl->device_list_lock);
+ core_disable_device_list_for_node(lun, NULL, mapped_lun,
+ TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg);
}
- spin_unlock_irq(&nacl->device_list_lock);
spin_lock_irq(&tpg->acl_node_lock);
}
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index b2fdba5..15a683b 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -55,32 +55,32 @@ static void core_clear_initiator_node_from_tpg(
struct se_node_acl *nacl,
struct se_portal_group *tpg)
{
- int i;
struct se_dev_entry *deve;
struct se_lun *lun;
+ u32 i, mapped_lun;
- spin_lock_irq(&nacl->device_list_lock);
for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
- deve = nacl->device_list[i];
+ rcu_read_lock();
+ deve = rcu_dereference(nacl->lun_entry_hlist[i]);
- if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS))
+ if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS)) {
+ rcu_read_unlock();
continue;
-
+ }
if (!deve->se_lun) {
pr_err("%s device entries device pointer is"
" NULL, but Initiator has access.\n",
tpg->se_tpg_tfo->get_fabric_name());
+ rcu_read_unlock();
continue;
}
-
lun = deve->se_lun;
- spin_unlock_irq(&nacl->device_list_lock);
- core_disable_device_list_for_node(lun, NULL, deve->mapped_lun,
- TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg);
+ mapped_lun = deve->mapped_lun;
+ rcu_read_unlock();
- spin_lock_irq(&nacl->device_list_lock);
+ core_disable_device_list_for_node(lun, NULL, mapped_lun,
+ TRANSPORT_LUNFLAGS_NO_ACCESS, nacl, tpg);
}
- spin_unlock_irq(&nacl->device_list_lock);
}
/* __core_tpg_get_initiator_node_acl():
--
1.9.1
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