From patchwork Tue May 12 09:25:30 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Nicholas A. 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[67.23.28.174]) by mx.google.com with ESMTPSA id z133sm10658470oif.14.2015.05.12.02.28.05 (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 12 May 2015 02:28:05 -0700 (PDT) From: "Nicholas A. Bellinger" To: target-devel Cc: linux-scsi , linux-kernel , Hannes Reinecke , Christoph Hellwig , Sagi Grimberg , Nicholas Bellinger Subject: [PATCH 06/12] target/pr: Convert se_dev_entry to kref for RCU Date: Tue, 12 May 2015 09:25:30 +0000 Message-Id: <1431422736-29125-7-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-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Nicholas Bellinger This patch converts se_dev_entry->pr_ref_count access to use modern struct kref counting. It updates core_enable_device_list_for_node() to kref_init() when se_dev_entry is being enabled, and updates core_disable_device_list_for_node() to kref_put() and blocks on ->pr_comp waiting for outstanding PR references to drop. Also, go ahead and convert core_get_se_deve_from_rtpi() code to use pr_kref for RELATIVE TARGET PORT IDENTIFIER lookup. Cc: Hannes Reinecke Cc: Christoph Hellwig Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 27 ++++++++---- drivers/target/target_core_internal.h | 1 + drivers/target/target_core_pr.c | 78 ++++++++++++++++++++++------------- include/target/target_core_base.h | 4 +- 4 files changed, 71 insertions(+), 39 deletions(-) diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 36e7d13..911758b 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -203,7 +203,7 @@ EXPORT_SYMBOL(transport_lookup_tmr_lun); /* * This function is called from core_scsi3_emulate_pro_register_and_move() - * and core_scsi3_decode_spec_i_port(), and will increment &deve->pr_ref_count + * and core_scsi3_decode_spec_i_port(), and will increment &deve->pr_kref * when a matching rtpi is found. */ struct se_dev_entry *core_get_se_deve_from_rtpi( @@ -237,7 +237,7 @@ struct se_dev_entry *core_get_se_deve_from_rtpi( if (port->sep_rtpi != rtpi) continue; - atomic_inc_mb(&deve->pr_ref_count); + kref_get(&deve->pr_kref); rcu_read_unlock(); return deve; @@ -323,6 +323,13 @@ struct se_dev_entry *target_nacl_find_deve(struct se_node_acl *nacl, u32 mapped_ } EXPORT_SYMBOL(target_nacl_find_deve); +void target_pr_kref_release(struct kref *kref) +{ + struct se_dev_entry *deve = container_of(kref, struct se_dev_entry, + pr_kref); + complete(&deve->pr_comp); +} + /* core_enable_device_list_for_node(): * * @@ -353,6 +360,9 @@ int core_enable_device_list_for_node( new->mapped_lun = mapped_lun; new->lun_flags |= TRANSPORT_LUNFLAGS_INITIATOR_ACCESS; + kref_init(&new->pr_kref); + init_completion(&new->pr_comp); + if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) new->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE; else @@ -377,6 +387,9 @@ int core_enable_device_list_for_node( list_add_tail(&new->alua_port_list, &port->sep_alua_list); spin_unlock_bh(&port->sep_alua_lock); + kref_put(&orig->pr_kref, target_pr_kref_release); + wait_for_completion(&orig->pr_comp); + call_rcu(&orig->rcu_head, target_nacl_deve_callrcu); return 0; } @@ -432,13 +445,6 @@ int core_disable_device_list_for_node( 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(&orig->pr_ref_count) != 0) - cpu_relax(); - - /* * Disable struct se_dev_entry LUN ACL mapping */ core_scsi3_ua_release_all(orig); @@ -450,6 +456,9 @@ int core_disable_device_list_for_node( hlist_del_rcu(&orig->link); mutex_unlock(&nacl->lun_entry_mutex); + kref_put(&orig->pr_kref, target_pr_kref_release); + wait_for_completion(&orig->pr_comp); + /* * Fire off RCU callback to wait for any in process SPEC_I_PT=1 * or REGISTER_AND_MOVE PR operation to complete. diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h index 9c4bce0..f57bb61 100644 --- a/drivers/target/target_core_internal.h +++ b/drivers/target/target_core_internal.h @@ -9,6 +9,7 @@ extern struct mutex g_device_mutex; extern struct list_head g_device_list; struct se_dev_entry *core_get_se_deve_from_rtpi(struct se_node_acl *, u16); +void target_pr_kref_release(struct kref *); 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 *); diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c index 721b664..c0b593a 100644 --- a/drivers/target/target_core_pr.c +++ b/drivers/target/target_core_pr.c @@ -48,7 +48,7 @@ struct pr_transport_id_holder { struct t10_pr_registration *dest_pr_reg; struct se_portal_group *dest_tpg; struct se_node_acl *dest_node_acl; - struct se_dev_entry *dest_se_deve; + struct se_dev_entry __rcu *dest_se_deve; struct list_head dest_list; }; @@ -232,7 +232,7 @@ target_scsi2_reservation_release(struct se_cmd *cmd) tpg = sess->se_tpg; pr_debug("SCSI-2 Released reservation for %s LUN: %u ->" " MAPPED LUN: %u for %s\n", tpg->se_tpg_tfo->get_fabric_name(), - cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun, + cmd->se_lun->unpacked_lun, cmd->orig_fe_lun, sess->se_node_acl->initiatorname); out_unlock: @@ -281,7 +281,7 @@ target_scsi2_reservation_reserve(struct se_cmd *cmd) dev->dev_reserved_node_acl->initiatorname); pr_err("Current attempt - LUN: %u -> MAPPED LUN: %u" " from %s \n", cmd->se_lun->unpacked_lun, - cmd->se_deve->mapped_lun, + cmd->orig_fe_lun, sess->se_node_acl->initiatorname); ret = TCM_RESERVATION_CONFLICT; goto out_unlock; @@ -295,7 +295,7 @@ target_scsi2_reservation_reserve(struct se_cmd *cmd) } pr_debug("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u" " for %s\n", tpg->se_tpg_tfo->get_fabric_name(), - cmd->se_lun->unpacked_lun, cmd->se_deve->mapped_lun, + cmd->se_lun->unpacked_lun, cmd->orig_fe_lun, sess->se_node_acl->initiatorname); out_unlock: @@ -320,6 +320,7 @@ static int core_scsi3_pr_seq_non_holder( unsigned char *cdb = cmd->t_task_cdb; struct se_dev_entry *se_deve; struct se_session *se_sess = cmd->se_sess; + struct se_node_acl *nacl = se_sess->se_node_acl; int other_cdb = 0, ignore_reg; int registered_nexus = 0, ret = 1; /* Conflict by default */ int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */ @@ -327,7 +328,8 @@ static int core_scsi3_pr_seq_non_holder( int legacy = 0; /* Act like a legacy device and return * RESERVATION CONFLICT on some CDBs */ - se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun]; + rcu_read_lock(); + se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun); /* * Determine if the registration should be ignored due to * non-matching ISIDs in target_scsi3_pr_reservation_check(). @@ -368,8 +370,10 @@ static int core_scsi3_pr_seq_non_holder( registered_nexus = 1; break; default: + rcu_read_unlock(); return -EINVAL; } + rcu_read_unlock(); /* * Referenced from spc4r17 table 45 for *NON* PR holder access */ @@ -735,7 +739,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration( if (strcmp(nacl->initiatorname, nacl_tmp->initiatorname)) continue; - atomic_inc_mb(&deve_tmp->pr_ref_count); + kref_get(&deve_tmp->pr_kref); spin_unlock_bh(&port->sep_alua_lock); /* * Grab a configfs group dependency that is released @@ -748,7 +752,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration( pr_err("core_scsi3_lunacl_depend" "_item() failed\n"); atomic_dec_mb(&port->sep_tg_pt_ref_cnt); - atomic_dec_mb(&deve_tmp->pr_ref_count); + kref_put(&deve_tmp->pr_kref, target_pr_kref_release); goto out; } /* @@ -763,7 +767,6 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration( sa_res_key, all_tg_pt, aptpl); if (!pr_reg_atp) { atomic_dec_mb(&port->sep_tg_pt_ref_cnt); - atomic_dec_mb(&deve_tmp->pr_ref_count); core_scsi3_lunacl_undepend_item(deve_tmp); goto out; } @@ -896,7 +899,7 @@ static int __core_scsi3_check_aptpl_registration( struct se_lun *lun, u32 target_lun, struct se_node_acl *nacl, - struct se_dev_entry *deve) + u32 mapped_lun) { struct t10_pr_registration *pr_reg, *pr_reg_tmp; struct t10_reservation *pr_tmpl = &dev->t10_pr; @@ -924,13 +927,12 @@ static int __core_scsi3_check_aptpl_registration( pr_reg_aptpl_list) { if (!strcmp(pr_reg->pr_iport, i_port) && - (pr_reg->pr_res_mapped_lun == deve->mapped_lun) && + (pr_reg->pr_res_mapped_lun == mapped_lun) && !(strcmp(pr_reg->pr_tport, t_port)) && (pr_reg->pr_reg_tpgt == tpgt) && (pr_reg->pr_aptpl_target_lun == target_lun)) { pr_reg->pr_reg_nacl = nacl; - pr_reg->pr_reg_deve = deve; pr_reg->pr_reg_tg_pt_lun = lun; list_del(&pr_reg->pr_reg_aptpl_list); @@ -968,13 +970,12 @@ int core_scsi3_check_aptpl_registration( struct se_node_acl *nacl, u32 mapped_lun) { - struct se_dev_entry *deve = nacl->device_list[mapped_lun]; - if (dev->dev_reservation_flags & DRF_SPC2_RESERVATIONS) return 0; return __core_scsi3_check_aptpl_registration(dev, tpg, lun, - lun->unpacked_lun, nacl, deve); + lun->unpacked_lun, nacl, + mapped_lun); } static void __core_scsi3_dump_registration( @@ -1409,27 +1410,35 @@ static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve) static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve) { - struct se_lun_acl *lun_acl = se_deve->se_lun_acl; + struct se_lun_acl *lun_acl; struct se_node_acl *nacl; struct se_portal_group *tpg; + + if (!se_deve) { + pr_err("core_scsi3_lunacl_undepend_item passed NULL se_deve\n"); + dump_stack(); + return; + } /* * For nacl->dynamic_node_acl=1 */ + lun_acl = se_deve->se_lun_acl; if (!lun_acl) { - atomic_dec_mb(&se_deve->pr_ref_count); + kref_put(&se_deve->pr_kref, target_pr_kref_release); return; } nacl = lun_acl->se_lun_nacl; tpg = nacl->se_tpg; target_undepend_item(&lun_acl->se_lun_group.cg_item); - atomic_dec_mb(&se_deve->pr_ref_count); + kref_put(&se_deve->pr_kref, target_pr_kref_release); } static sense_reason_t core_scsi3_decode_spec_i_port( struct se_cmd *cmd, struct se_portal_group *tpg, + struct se_dev_entry *local_se_deve, unsigned char *l_isid, u64 sa_res_key, int all_tg_pt, @@ -1440,7 +1449,7 @@ core_scsi3_decode_spec_i_port( struct se_portal_group *dest_tpg = NULL, *tmp_tpg; struct se_session *se_sess = cmd->se_sess; struct se_node_acl *dest_node_acl = NULL; - struct se_dev_entry *dest_se_deve = NULL, *local_se_deve; + struct se_dev_entry __rcu *dest_se_deve = NULL; struct t10_pr_registration *dest_pr_reg, *local_pr_reg, *pr_reg_e; struct t10_pr_registration *pr_reg_tmp, *pr_reg_tmp_safe; LIST_HEAD(tid_dest_list); @@ -1453,7 +1462,6 @@ core_scsi3_decode_spec_i_port( int dest_local_nexus; u32 dest_rtpi = 0; - local_se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun]; /* * Allocate a struct pr_transport_id_holder and setup the * local_node_acl and local_se_deve pointers and add to @@ -1468,7 +1476,6 @@ core_scsi3_decode_spec_i_port( INIT_LIST_HEAD(&tidh_new->dest_list); tidh_new->dest_tpg = tpg; tidh_new->dest_node_acl = se_sess->se_node_acl; - tidh_new->dest_se_deve = local_se_deve; local_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev, se_sess->se_node_acl, local_se_deve, l_isid, @@ -1477,6 +1484,7 @@ core_scsi3_decode_spec_i_port( kfree(tidh_new); return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } + rcu_assign_pointer(tidh_new->dest_se_deve, local_se_deve); tidh_new->dest_pr_reg = local_pr_reg; /* * The local I_T nexus does not hold any configfs dependances, @@ -1636,7 +1644,7 @@ core_scsi3_decode_spec_i_port( if (core_scsi3_lunacl_depend_item(dest_se_deve)) { pr_err("core_scsi3_lunacl_depend_item()" " failed\n"); - atomic_dec_mb(&dest_se_deve->pr_ref_count); + kref_put(&dest_se_deve->pr_kref, target_pr_kref_release); core_scsi3_nodeacl_undepend_item(dest_node_acl); core_scsi3_tpg_undepend_item(dest_tpg); ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; @@ -1991,6 +1999,7 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, bool aptpl, bool all_tg_pt, bool spec_i_pt, enum register_type register_type) { struct se_session *se_sess = cmd->se_sess; + struct se_node_acl *nacl = se_sess->se_node_acl; struct se_device *dev = cmd->se_dev; struct se_dev_entry *se_deve; struct se_lun *se_lun = cmd->se_lun; @@ -2006,7 +2015,14 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } se_tpg = se_sess->se_tpg; - se_deve = se_sess->se_node_acl->device_list[cmd->orig_fe_lun]; + + rcu_read_lock(); + se_deve = target_nacl_find_deve(nacl, cmd->orig_fe_lun); + if (!se_deve) { + pr_err("Unable to locate se_deve for PRO-REGISTER\n"); + rcu_read_unlock(); + return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + } if (se_tpg->se_tpg_tfo->sess_get_initiator_sid) { memset(&isid_buf[0], 0, PR_REG_ISID_LEN); @@ -2022,14 +2038,16 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, if (res_key) { pr_warn("SPC-3 PR: Reservation Key non-zero" " for SA REGISTER, returning CONFLICT\n"); + rcu_read_unlock(); return TCM_RESERVATION_CONFLICT; } /* * Do nothing but return GOOD status. */ - if (!sa_res_key) + if (!sa_res_key) { + rcu_read_unlock(); return 0; - + } if (!spec_i_pt) { /* * Perform the Service Action REGISTER on the Initiator @@ -2042,6 +2060,7 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, register_type, 0)) { pr_err("Unable to allocate" " struct t10_pr_registration\n"); + rcu_read_unlock(); return TCM_INVALID_PARAMETER_LIST; } } else { @@ -2053,14 +2072,17 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, * logic from of core_scsi3_alloc_registration() for * each TransportID provided SCSI Initiator Port/Device */ - ret = core_scsi3_decode_spec_i_port(cmd, se_tpg, + ret = core_scsi3_decode_spec_i_port(cmd, se_tpg, se_deve, isid_ptr, sa_res_key, all_tg_pt, aptpl); - if (ret != 0) + if (ret != 0) { + rcu_read_unlock(); return ret; + } } - + rcu_read_unlock(); return core_scsi3_update_and_write_aptpl(dev, aptpl); } + rcu_read_unlock(); /* ok, existing registration */ @@ -3322,7 +3344,7 @@ after_iport_check: if (core_scsi3_lunacl_depend_item(dest_se_deve)) { pr_err("core_scsi3_lunacl_depend_item() failed\n"); - atomic_dec_mb(&dest_se_deve->pr_ref_count); + kref_put(&dest_se_deve->pr_kref, target_pr_kref_release); dest_se_deve = NULL; ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; goto out; diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 3057eff..1b06d27 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -585,7 +585,6 @@ struct se_node_acl { /* 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; struct mutex lun_entry_mutex; @@ -653,7 +652,8 @@ struct se_dev_entry { u64 write_bytes; atomic_t ua_count; /* Used for PR SPEC_I_PT=1 and REGISTER_AND_MOVE */ - atomic_t pr_ref_count; + struct kref pr_kref; + struct completion pr_comp; struct se_node_acl *se_node_acl; struct se_lun_acl __rcu *se_lun_acl; spinlock_t ua_lock;