target: Convert se_node_acl->device_list[] to RCU hlist
This patch converts se_node_acl->device_list[] table for mappedluns
to modern RCU hlist_head usage in order to support an arbitrary number
of node_acl lun mappings.
It converts transport_lookup_*_lun() fast-path code to use RCU read path
primitives when looking up se_dev_entry. It adds a new hlist_head at
se_node_acl->lun_entry_hlist for this purpose.
For transport_lookup_cmd_lun() code, it works with existing per-cpu
se_lun->lun_ref when associating se_cmd with se_lun + se_device.
Also, go ahead and update core_create_device_list_for_node() +
core_free_device_list_for_node() to use ->lun_entry_hlist.
It also converts se_dev_entry->pr_ref_count access to use modern
struct kref counting, and updates core_disable_device_list_for_node()
to kref_put() and block on se_deve->pr_comp waiting for outstanding PR
special-case PR references to drop, then invoke kfree_rcu() to wait
for the RCU grace period to complete before releasing memory.
So now that se_node_acl->lun_entry_hlist fast path access uses RCU
protected pointers, go ahead and convert remaining non-fast path
RCU updater code using ->lun_entry_lock to struct mutex to allow
callers to block while walking se_node_acl->lun_entry_hlist.
Finally drop the left-over core_clear_initiator_node_from_tpg() that
originally cleared lun_access during se_node_acl shutdown, as post
RCU conversion it now becomes duplicated logic.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_stat.c b/drivers/target/target_core_stat.c
index 64efee2..ea12879 100644
--- a/drivers/target/target_core_stat.c
+++ b/drivers/target/target_core_stat.c
@@ -1084,17 +1084,17 @@
struct se_portal_group *tpg;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
tpg = nacl->se_tpg;
/* scsiInstIndex */
ret = snprintf(page, PAGE_SIZE, "%u\n",
tpg->se_tpg_tfo->tpg_get_inst_index(tpg));
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(inst);
@@ -1109,16 +1109,16 @@
struct se_lun *lun;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
- lun = deve->se_lun;
+ lun = rcu_dereference(deve->se_lun);
/* scsiDeviceIndex */
- ret = snprintf(page, PAGE_SIZE, "%u\n", lun->lun_se_dev->dev_index);
- spin_unlock_irq(&nacl->device_list_lock);
+ ret = snprintf(page, PAGE_SIZE, "%u\n", lun->lun_index);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(dev);
@@ -1133,16 +1133,16 @@
struct se_portal_group *tpg;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
tpg = nacl->se_tpg;
/* scsiAuthIntrTgtPortIndex */
ret = snprintf(page, PAGE_SIZE, "%u\n", tpg->se_tpg_tfo->tpg_get_tag(tpg));
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(port);
@@ -1156,15 +1156,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrIndex */
ret = snprintf(page, PAGE_SIZE, "%u\n", nacl->acl_index);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(indx);
@@ -1178,15 +1178,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrDevOrPort */
ret = snprintf(page, PAGE_SIZE, "%u\n", 1);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(dev_or_port);
@@ -1200,15 +1200,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrName */
ret = snprintf(page, PAGE_SIZE, "%s\n", nacl->initiatorname);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(intr_name);
@@ -1222,15 +1222,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* FIXME: scsiAuthIntrLunMapIndex */
ret = snprintf(page, PAGE_SIZE, "%u\n", 0);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(map_indx);
@@ -1244,15 +1244,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrAttachedTimes */
ret = snprintf(page, PAGE_SIZE, "%u\n", deve->attach_count);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(att_count);
@@ -1266,15 +1266,16 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrOutCommands */
- ret = snprintf(page, PAGE_SIZE, "%u\n", deve->total_cmds);
- spin_unlock_irq(&nacl->device_list_lock);
+ ret = snprintf(page, PAGE_SIZE, "%lu\n",
+ atomic_long_read(&deve->total_cmds));
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(num_cmds);
@@ -1288,15 +1289,16 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrReadMegaBytes */
- ret = snprintf(page, PAGE_SIZE, "%u\n", (u32)(deve->read_bytes >> 20));
- spin_unlock_irq(&nacl->device_list_lock);
+ ret = snprintf(page, PAGE_SIZE, "%u\n",
+ (u32)(atomic_long_read(&deve->read_bytes) >> 20));
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(read_mbytes);
@@ -1310,15 +1312,16 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrWrittenMegaBytes */
- ret = snprintf(page, PAGE_SIZE, "%u\n", (u32)(deve->write_bytes >> 20));
- spin_unlock_irq(&nacl->device_list_lock);
+ ret = snprintf(page, PAGE_SIZE, "%u\n",
+ (u32)(atomic_long_read(&deve->write_bytes) >> 20));
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(write_mbytes);
@@ -1332,15 +1335,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* FIXME: scsiAuthIntrHSOutCommands */
ret = snprintf(page, PAGE_SIZE, "%u\n", 0);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(hs_num_cmds);
@@ -1354,16 +1357,16 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAuthIntrLastCreation */
ret = snprintf(page, PAGE_SIZE, "%u\n", (u32)(((u32)deve->creation_time -
INITIAL_JIFFIES) * 100 / HZ));
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(creation_time);
@@ -1377,15 +1380,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* FIXME: scsiAuthIntrRowStatus */
ret = snprintf(page, PAGE_SIZE, "Ready\n");
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_AUTH_INTR_ATTR_RO(row_status);
@@ -1450,17 +1453,17 @@
struct se_portal_group *tpg;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
tpg = nacl->se_tpg;
/* scsiInstIndex */
ret = snprintf(page, PAGE_SIZE, "%u\n",
tpg->se_tpg_tfo->tpg_get_inst_index(tpg));
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_ATTR_INTR_PORT_ATTR_RO(inst);
@@ -1475,16 +1478,16 @@
struct se_lun *lun;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
- lun = deve->se_lun;
+ lun = rcu_dereference(deve->se_lun);
/* scsiDeviceIndex */
- ret = snprintf(page, PAGE_SIZE, "%u\n", lun->lun_se_dev->dev_index);
- spin_unlock_irq(&nacl->device_list_lock);
+ ret = snprintf(page, PAGE_SIZE, "%u\n", lun->lun_index);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_ATTR_INTR_PORT_ATTR_RO(dev);
@@ -1499,16 +1502,16 @@
struct se_portal_group *tpg;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
tpg = nacl->se_tpg;
/* scsiPortIndex */
ret = snprintf(page, PAGE_SIZE, "%u\n", tpg->se_tpg_tfo->tpg_get_tag(tpg));
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_ATTR_INTR_PORT_ATTR_RO(port);
@@ -1548,15 +1551,15 @@
struct se_dev_entry *deve;
ssize_t ret;
- spin_lock_irq(&nacl->device_list_lock);
- deve = nacl->device_list[lacl->mapped_lun];
- if (!deve->se_lun || !deve->se_lun_acl) {
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_lock();
+ deve = target_nacl_find_deve(nacl, lacl->mapped_lun);
+ if (!deve) {
+ rcu_read_unlock();
return -ENODEV;
}
/* scsiAttIntrPortAuthIntrIdx */
ret = snprintf(page, PAGE_SIZE, "%u\n", nacl->acl_index);
- spin_unlock_irq(&nacl->device_list_lock);
+ rcu_read_unlock();
return ret;
}
DEV_STAT_SCSI_ATTR_INTR_PORT_ATTR_RO(port_auth_indx);