From 29a05deebf6c2e3010934fb78ee65cab3d329470 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sun, 22 Mar 2015 20:42:19 -0700 Subject: 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 Cc: Christoph Hellwig Cc: Sagi Grimberg Cc: Paul E. McKenney Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_stat.c | 197 +++++++++++++++++++------------------- 1 file changed, 100 insertions(+), 97 deletions(-) (limited to 'drivers/target/target_core_stat.c') diff --git a/drivers/target/target_core_stat.c b/drivers/target/target_core_stat.c index 64efee2fba52..ea1287940a7c 100644 --- a/drivers/target/target_core_stat.c +++ b/drivers/target/target_core_stat.c @@ -1084,17 +1084,17 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_inst( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_dev( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_port( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_indx( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_dev_or_port( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_intr_name( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_map_indx( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_att_count( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_num_cmds( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_read_mbytes( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_write_mbytes( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_hs_num_cmds( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_creation_time( 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 @@ static ssize_t target_stat_scsi_auth_intr_show_attr_row_status( 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 @@ static ssize_t target_stat_scsi_att_intr_port_show_attr_inst( 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 @@ static ssize_t target_stat_scsi_att_intr_port_show_attr_dev( 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 @@ static ssize_t target_stat_scsi_att_intr_port_show_attr_port( 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 @@ static ssize_t target_stat_scsi_att_intr_port_show_attr_port_auth_indx( 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); -- cgit v1.2.3-55-g7522