Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932742AbbELJh4 (ORCPT ); Tue, 12 May 2015 05:37:56 -0400 Received: from mail-ob0-f182.google.com ([209.85.214.182]:36848 "EHLO mail-ob0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932339AbbELJ17 (ORCPT ); Tue, 12 May 2015 05:27:59 -0400 From: "Nicholas A. Bellinger" To: target-devel Cc: linux-scsi , linux-kernel , Hannes Reinecke , Christoph Hellwig , Sagi Grimberg , Nicholas Bellinger Subject: [PATCH 01/12] target: Convert se_node_acl->device_list[] to RCU hlist Date: Tue, 12 May 2015 09:25:25 +0000 Message-Id: <1431422736-29125-2-git-send-email-nab@daterainc.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1431422736-29125-1-git-send-email-nab@daterainc.com> References: <1431422736-29125-1-git-send-email-nab@daterainc.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 15314 Lines: 471 From: Nicholas Bellinger 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. This includes changes to core_[enable,disable]_device_list_for_node() rcu_assign_pointer() and invokes call_rcu() for releasing memory, along with a number of RCU read path conversions in target_core_device.c code. Required for subsequent conversion of transport_lookup_cmd() to lock-less RCU read path. Cc: Hannes Reinecke Cc: Christoph Hellwig Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 218 +++++++++++++++++++--------------- drivers/target/target_core_internal.h | 1 + drivers/target/target_core_tpg.c | 23 ++-- include/target/target_core_base.h | 7 +- 4 files changed, 137 insertions(+), 112 deletions(-) diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 6e58976..1df14ce 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -198,12 +198,9 @@ struct se_dev_entry *core_get_se_deve_from_rtpi( struct se_lun *lun; struct se_port *port; struct se_portal_group *tpg = nacl->se_tpg; - u32 i; - - 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(); + hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) { if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS)) continue; @@ -225,11 +222,11 @@ struct se_dev_entry *core_get_se_deve_from_rtpi( continue; atomic_inc_mb(&deve->pr_ref_count); - spin_unlock_irq(&nacl->device_list_lock); + rcu_read_unlock(); return deve; } - spin_unlock_irq(&nacl->device_list_lock); + rcu_read_unlock(); return NULL; } @@ -240,18 +237,12 @@ int core_free_device_list_for_node( { struct se_dev_entry *deve; struct se_lun *lun; - u32 i; - - if (!nacl->device_list) - return 0; - - spin_lock_irq(&nacl->device_list_lock); - for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) { - deve = nacl->device_list[i]; + u32 mapped_lun; + rcu_read_lock(); + hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) { if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS)) continue; - if (!deve->se_lun) { pr_err("%s device entries device pointer is" " NULL, but Initiator has access.\n", @@ -259,16 +250,14 @@ int core_free_device_list_for_node( 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); + rcu_read_lock(); } - spin_unlock_irq(&nacl->device_list_lock); - - array_free(nacl->device_list, TRANSPORT_MAX_LUNS_PER_TPG); - nacl->device_list = NULL; + rcu_read_unlock(); return 0; } @@ -280,18 +269,44 @@ void core_update_device_list_access( { struct se_dev_entry *deve; - spin_lock_irq(&nacl->device_list_lock); - deve = nacl->device_list[mapped_lun]; - if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) { - deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY; - deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE; - } else { - deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE; - deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY; + spin_lock_irq(&nacl->lun_entry_lock); + deve = target_nacl_find_deve(nacl, mapped_lun); + if (deve) { + if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) { + deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY; + deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE; + } else { + 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(); +} + +static void target_nacl_deve_callrcu(struct rcu_head *head) +{ + struct se_dev_entry *deve = container_of(head, struct se_dev_entry, + rcu_head); + kfree(deve); } +/* + * Called with rcu_read_lock or nacl->device_list_lock held. + */ +struct se_dev_entry *target_nacl_find_deve(struct se_node_acl *nacl, u32 mapped_lun) +{ + struct se_dev_entry *deve; + + hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) + if (deve->mapped_lun == mapped_lun) + return deve; + + return NULL; +} +EXPORT_SYMBOL(target_nacl_find_deve); + /* core_enable_device_list_for_node(): * * @@ -305,67 +320,61 @@ int core_enable_device_list_for_node( struct se_portal_group *tpg) { struct se_port *port = lun->lun_sep; - struct se_dev_entry *deve; + struct se_dev_entry *orig, *new; - spin_lock_irq(&nacl->device_list_lock); + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) { + pr_err("Unable to allocate se_dev_entry memory\n"); + return -ENOMEM; + } - deve = nacl->device_list[mapped_lun]; + new->se_node_acl = nacl; + atomic_set(&new->ua_count, 0); + spin_lock_init(&new->ua_lock); + INIT_LIST_HEAD(&new->alua_port_list); + INIT_LIST_HEAD(&new->ua_list); - /* - * Check if the call is handling demo mode -> explicit LUN ACL - * transition. This transition must be for the same struct se_lun - * + mapped_lun that was setup in demo mode.. - */ - if (deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS) { - if (deve->se_lun_acl != NULL) { - pr_err("struct se_dev_entry->se_lun_acl" - " already set for demo mode -> explicit" - " LUN ACL transition\n"); - spin_unlock_irq(&nacl->device_list_lock); - return -EINVAL; - } - if (deve->se_lun != lun) { - pr_err("struct se_dev_entry->se_lun does" - " match passed struct se_lun for demo mode" - " -> explicit LUN ACL transition\n"); - spin_unlock_irq(&nacl->device_list_lock); - return -EINVAL; - } - deve->se_lun_acl = lun_acl; + new->mapped_lun = mapped_lun; + new->lun_flags |= TRANSPORT_LUNFLAGS_INITIATOR_ACCESS; - if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) { - deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY; - deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE; - } else { - deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE; - deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY; - } + if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) + new->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE; + else + new->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY; + + new->creation_time = get_jiffies_64(); + new->attach_count++; + spin_lock_irq(&nacl->device_list_lock); + orig = target_nacl_find_deve(nacl, mapped_lun); + if (orig && orig->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS) { + BUG_ON(orig->se_lun_acl != NULL); + BUG_ON(orig->se_lun != lun); + + rcu_assign_pointer(new->se_lun, lun); + rcu_assign_pointer(new->se_lun_acl, lun_acl); + hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist); spin_unlock_irq(&nacl->device_list_lock); - return 0; - } - deve->se_lun = lun; - deve->se_lun_acl = lun_acl; - deve->mapped_lun = mapped_lun; - deve->lun_flags |= TRANSPORT_LUNFLAGS_INITIATOR_ACCESS; + spin_lock_bh(&port->sep_alua_lock); + list_del(&orig->alua_port_list); + list_add_tail(&new->alua_port_list, &port->sep_alua_list); + spin_unlock_bh(&port->sep_alua_lock); - if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) { - deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY; - deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE; - } else { - deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE; - deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY; + call_rcu(&orig->rcu_head, target_nacl_deve_callrcu); + return 0; } - deve->creation_time = get_jiffies_64(); - deve->attach_count++; + rcu_assign_pointer(new->se_lun, lun); + rcu_assign_pointer(new->se_lun_acl, lun_acl); + hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist); spin_unlock_irq(&nacl->device_list_lock); spin_lock_bh(&port->sep_alua_lock); - list_add_tail(&deve->alua_port_list, &port->sep_alua_list); + list_add_tail(&new->alua_port_list, &port->sep_alua_list); spin_unlock_bh(&port->sep_alua_lock); + synchronize_rcu(); return 0; } @@ -382,8 +391,14 @@ int core_disable_device_list_for_node( struct se_portal_group *tpg) { struct se_port *port = lun->lun_sep; - struct se_dev_entry *deve = nacl->device_list[mapped_lun]; + struct se_dev_entry *orig; + spin_lock_irq(&nacl->device_list_lock); + orig = target_nacl_find_deve(nacl, mapped_lun); + if (!orig) { + spin_unlock_irq(&nacl->device_list_lock); + return 0; + } /* * If the MappedLUN entry is being disabled, the entry in * port->sep_alua_list must be removed now before clearing the @@ -398,27 +413,33 @@ int core_disable_device_list_for_node( * MappedLUN *deve will be released below.. */ spin_lock_bh(&port->sep_alua_lock); - list_del(&deve->alua_port_list); + list_del(&orig->alua_port_list); spin_unlock_bh(&port->sep_alua_lock); /* * Wait for any in process SPEC_I_PT=1 or REGISTER_AND_MOVE * PR operation to complete. */ - while (atomic_read(&deve->pr_ref_count) != 0) + while (atomic_read(&orig->pr_ref_count) != 0) cpu_relax(); - spin_lock_irq(&nacl->device_list_lock); /* * Disable struct se_dev_entry LUN ACL mapping */ - core_scsi3_ua_release_all(deve); - deve->se_lun = NULL; - deve->se_lun_acl = NULL; - deve->lun_flags = 0; - deve->creation_time = 0; - deve->attach_count--; + core_scsi3_ua_release_all(orig); + rcu_assign_pointer(orig->se_lun, NULL); + rcu_assign_pointer(orig->se_lun_acl, NULL); + orig->lun_flags = 0; + orig->creation_time = 0; + orig->attach_count--; + hlist_del_rcu(&orig->link); spin_unlock_irq(&nacl->device_list_lock); + /* + * Fire off RCU callback to wait for any in process SPEC_I_PT=1 + * or REGISTER_AND_MOVE PR operation to complete. + */ + call_rcu(&orig->rcu_head, target_nacl_deve_callrcu); + core_scsi3_free_pr_reg_from_nacl(lun->lun_se_dev, nacl); return 0; } @@ -431,26 +452,25 @@ 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 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]; + rcu_read_lock(); + hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) { if (lun != deve->se_lun) 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); + rcu_read_lock(); } - spin_unlock_irq(&nacl->device_list_lock); + rcu_read_unlock(); spin_lock_irq(&tpg->acl_node_lock); } diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h index d0344ad..9c4bce0 100644 --- a/drivers/target/target_core_internal.h +++ b/drivers/target/target_core_internal.h @@ -12,6 +12,7 @@ struct se_dev_entry *core_get_se_deve_from_rtpi(struct se_node_acl *, u16); int core_free_device_list_for_node(struct se_node_acl *, struct se_portal_group *); void core_update_device_list_access(u32, u32, struct se_node_acl *); +struct se_dev_entry *target_nacl_find_deve(struct se_node_acl *, u32); int core_enable_device_list_for_node(struct se_lun *, struct se_lun_acl *, u32, u32, struct se_node_acl *, struct se_portal_group *); int core_disable_device_list_for_node(struct se_lun *, struct se_lun_acl *, diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index c0c1f67..dbdd3e3 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -55,32 +55,29 @@ 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 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(); + hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) { if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS)) 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()); 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); + rcu_read_lock(); } - spin_unlock_irq(&nacl->device_list_lock); + rcu_read_unlock(); } /* __core_tpg_get_initiator_node_acl(): @@ -266,10 +263,12 @@ static struct se_node_acl *target_alloc_node_acl(struct se_portal_group *tpg, INIT_LIST_HEAD(&acl->acl_list); INIT_LIST_HEAD(&acl->acl_sess_list); + INIT_HLIST_HEAD(&acl->lun_entry_hlist); kref_init(&acl->acl_kref); init_completion(&acl->acl_free_comp); spin_lock_init(&acl->device_list_lock); spin_lock_init(&acl->nacl_sess_lock); + spin_lock_init(&acl->lun_entry_lock); atomic_set(&acl->acl_pr_ref_count, 0); if (tpg->se_tpg_tfo->tpg_get_default_depth) acl->queue_depth = tpg->se_tpg_tfo->tpg_get_default_depth(tpg); diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 042a734..6fb38df 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -584,10 +584,12 @@ struct se_node_acl { char acl_tag[MAX_ACL_TAG_SIZE]; /* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */ atomic_t acl_pr_ref_count; + struct hlist_head lun_entry_hlist; struct se_dev_entry **device_list; struct se_session *nacl_sess; struct se_portal_group *se_tpg; spinlock_t device_list_lock; + spinlock_t lun_entry_lock; spinlock_t nacl_sess_lock; struct config_group acl_group; struct config_group acl_attrib_group; @@ -653,11 +655,14 @@ struct se_dev_entry { atomic_t ua_count; /* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */ atomic_t pr_ref_count; - struct se_lun_acl *se_lun_acl; + struct se_node_acl *se_node_acl; + struct se_lun_acl __rcu *se_lun_acl; spinlock_t ua_lock; struct se_lun *se_lun; struct list_head alua_port_list; struct list_head ua_list; + struct hlist_node link; + struct rcu_head rcu_head; }; struct se_dev_attrib { -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/