]> www.infradead.org Git - users/jedix/linux-maple.git/commitdiff
qla2xxx: added sess generations to detect RSCN update races
authorAlexei Potashnik <alexei@purestorage.com>
Tue, 14 Jul 2015 20:00:46 +0000 (16:00 -0400)
committerBrian Maly <brian.maly@oracle.com>
Thu, 2 Nov 2017 18:14:13 +0000 (14:14 -0400)
Orabug: 2684419726923029

RSCN processing in qla2xxx driver can run in parallel with ELS/IO
processing. As such the decision to remove disappeared fc port's
session could be stale, because a new login sequence has occurred
since and created a brand new session.

Previous mechanism of dealing with this by delaying deletion request
was prone to erroneous deletions if the event that was supposed to
cancel the deletion never arrived or has been delayed in processing.

New mechanism relies on a time-like generation counter to serialize
RSCN updates relative to ELS/IO updates.

Cc: <stable@vger.kernel.org> # v3.18+
Signed-off-by: Alexei Potashnik <alexei@purestorage.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
drivers/scsi/qla2xxx/qla_dbg.c
drivers/scsi/qla2xxx/qla_def.h
drivers/scsi/qla2xxx/qla_init.c
drivers/scsi/qla2xxx/qla_os.c
drivers/scsi/qla2xxx/qla_target.c
drivers/scsi/qla2xxx/qla_target.h

index 8d11529babe93615edc216c235555bfaa56cf814..1e3c010751310bb7a60faebe0d205b3cfb9cc8ed 100644 (file)
@@ -67,7 +67,7 @@
  * |                              |                    | 0xd101-0xd1fe |
  * |                              |                    | 0xd214-0xd2fe |
  * | Target Mode                 |       0xe080       |                |
- * | Target Mode Management      |       0xf091       | 0xf002         |
+ * | Target Mode Management      |       0xf096       | 0xf002         |
  * |                              |                    | 0xf046-0xf049  |
  * | Target Mode Task Management  |      0x1000d      |                |
  * ----------------------------------------------------------------------
index c4c2f02100ac3250787e3c7cf755ae269cd8516b..fd46fce57267c57a16d5e9aaacb311b71d5a5393 100644 (file)
@@ -3697,6 +3697,11 @@ typedef struct scsi_qla_host {
        struct list_head        qla_sess_op_cmd_list;
        spinlock_t              cmd_list_lock;
 
+       /* Counter to detect races between ELS and RSCN events */
+       atomic_t                generation_tick;
+       /* Time when global fcport update has been scheduled */
+       int                     total_fcport_update_gen;
+
        uint32_t        vp_abort_cnt;
 
        struct fc_vport *fc_vport;      /* holds fc_vport * for each vport */
index ddd6e244a91b31defde76f3136ab3ca285c1a859..9e8e36c598c3273efc650e199d0cb4c969e5bf52 100644 (file)
@@ -2951,24 +2951,14 @@ qla2x00_rport_del(void *data)
 {
        fc_port_t *fcport = data;
        struct fc_rport *rport;
-       scsi_qla_host_t *vha = fcport->vha;
        unsigned long flags;
-       unsigned long vha_flags;
 
        spin_lock_irqsave(fcport->vha->host->host_lock, flags);
        rport = fcport->drport ? fcport->drport: fcport->rport;
        fcport->drport = NULL;
        spin_unlock_irqrestore(fcport->vha->host->host_lock, flags);
-       if (rport) {
+       if (rport)
                fc_remote_port_delete(rport);
-               /*
-                * Release the target mode FC NEXUS in qla_target.c code
-                * if target mod is enabled.
-                */
-               spin_lock_irqsave(&vha->hw->hardware_lock, vha_flags);
-               qlt_fc_port_deleted(vha, fcport);
-               spin_unlock_irqrestore(&vha->hw->hardware_lock, vha_flags);
-       }
 }
 
 /**
@@ -3408,6 +3398,7 @@ qla2x00_configure_fabric(scsi_qla_host_t *vha)
        LIST_HEAD(new_fcports);
        struct qla_hw_data *ha = vha->hw;
        struct scsi_qla_host *base_vha = pci_get_drvdata(ha->pdev);
+       int             discovery_gen;
 
        /* If FL port exists, then SNS is present */
        if (IS_FWI2_CAPABLE(ha))
@@ -3478,6 +3469,14 @@ qla2x00_configure_fabric(scsi_qla_host_t *vha)
                        fcport->scan_state = QLA_FCPORT_SCAN;
                }
 
+               /* Mark the time right before querying FW for connected ports.
+                * This process is long, asynchronous and by the time it's done,
+                * collected information might not be accurate anymore. E.g.
+                * disconnected port might have re-connected and a brand new
+                * session has been created. In this case session's generation
+                * will be newer than discovery_gen. */
+               qlt_do_generation_tick(vha, &discovery_gen);
+
                rval = qla2x00_find_all_fabric_devs(vha, &new_fcports);
                if (rval != QLA_SUCCESS)
                        break;
@@ -3529,7 +3528,8 @@ qla2x00_configure_fabric(scsi_qla_host_t *vha)
                                            atomic_read(&fcport->state),
                                            fcport->flags, fcport->fc4_type,
                                            fcport->scan_state);
-                                       qlt_fc_port_deleted(vha, fcport);
+                                       qlt_fc_port_deleted(vha, fcport,
+                                           discovery_gen);
                                }
                        }
                }
@@ -4301,6 +4301,14 @@ qla2x00_update_fcports(scsi_qla_host_t *base_vha)
                            atomic_read(&fcport->state) != FCS_UNCONFIGURED) {
                                spin_unlock_irqrestore(&ha->vport_slock, flags);
                                qla2x00_rport_del(fcport);
+
+                               /*
+                                * Release the target mode FC NEXUS in
+                                * qla_target.c, if target mod is enabled.
+                                */
+                               qlt_fc_port_deleted(vha, fcport,
+                                   base_vha->total_fcport_update_gen);
+
                                spin_lock_irqsave(&ha->vport_slock, flags);
                        }
                }
index 9964ae7f715f3ae3c3b860a87533cf800163fdc8..b0f348789edb30652a0c77c85a2fb1294cb8982e 100644 (file)
@@ -3482,11 +3482,14 @@ qla2x00_schedule_rport_del(struct scsi_qla_host *vha, fc_port_t *fcport,
                spin_lock_irqsave(vha->host->host_lock, flags);
                fcport->drport = rport;
                spin_unlock_irqrestore(vha->host->host_lock, flags);
+               qlt_do_generation_tick(vha, &base_vha->total_fcport_update_gen);
                set_bit(FCPORT_UPDATE_NEEDED, &base_vha->dpc_flags);
                qla2xxx_wake_dpc(base_vha);
        } else {
+               int now;
                fc_remote_port_delete(rport);
-               qlt_fc_port_deleted(vha, fcport);
+               qlt_do_generation_tick(vha, &now);
+               qlt_fc_port_deleted(vha, fcport, now);
        }
 }
 
index 4bfd20e7615811dc6d5d248ee8f18a9a497fefcf..39a92cf8b86bfb71c6a42b00b4144765371cb459 100644 (file)
@@ -127,6 +127,16 @@ static struct workqueue_struct *qla_tgt_wq;
 static DEFINE_MUTEX(qla_tgt_mutex);
 static LIST_HEAD(qla_tgt_glist);
 
+/* This API intentionally takes dest as a parameter, rather than returning
+ * int value to avoid caller forgetting to issue wmb() after the store */
+void qlt_do_generation_tick(struct scsi_qla_host *vha, int *dest)
+{
+       scsi_qla_host_t *base_vha = pci_get_drvdata(vha->hw->pdev);
+       *dest = atomic_inc_return(&base_vha->generation_tick);
+       /* memory barrier */
+       wmb();
+}
+
 /* ha->hardware_lock supposed to be held on entry (to protect tgt->sess_list) */
 static struct qla_tgt_sess *qlt_find_sess_by_port_name(
        struct qla_tgt *tgt,
@@ -576,10 +586,12 @@ static void qlt_schedule_sess_for_deletion(struct qla_tgt_sess *sess,
        sess->expires = jiffies + dev_loss_tmo * HZ;
 
        ql_dbg(ql_dbg_tgt, sess->vha, 0xe048,
-           "qla_target(%d): session for port %8phC (loop ID %d) scheduled for "
-           "deletion in %u secs (expires: %lu) immed: %d, logout: %d\n",
-           sess->vha->vp_idx, sess->port_name, sess->loop_id, dev_loss_tmo,
-           sess->expires, immediate, sess->logout_on_delete);
+           "qla_target(%d): session for port %8phC (loop ID %d s_id %02x:%02x:%02x)"
+           " scheduled for deletion in %u secs (expires: %lu) immed: %d, logout: %d, gen: %#x\n",
+           sess->vha->vp_idx, sess->port_name, sess->loop_id,
+           sess->s_id.b.domain, sess->s_id.b.area, sess->s_id.b.al_pa,
+           dev_loss_tmo, sess->expires, immediate, sess->logout_on_delete,
+           sess->generation);
 
        if (immediate)
                mod_delayed_work(system_wq, &tgt->sess_del_work, 0);
@@ -734,6 +746,9 @@ static struct qla_tgt_sess *qlt_create_sess(
 
                        if (sess->local && !local)
                                sess->local = 0;
+
+                       qlt_do_generation_tick(vha, &sess->generation);
+
                        spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
                        return sess;
@@ -795,6 +810,7 @@ static struct qla_tgt_sess *qlt_create_sess(
        spin_lock_irqsave(&ha->hardware_lock, flags);
        list_add_tail(&sess->sess_list_entry, &vha->vha_tgt.qla_tgt->sess_list);
        vha->vha_tgt.qla_tgt->sess_count++;
+       qlt_do_generation_tick(vha, &sess->generation);
        spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf04b,
@@ -808,7 +824,7 @@ static struct qla_tgt_sess *qlt_create_sess(
 }
 
 /*
- * Called from drivers/scsi/qla2xxx/qla_init.c:qla2x00_reg_remote_port()
+ * Called from qla2x00_reg_remote_port()
  */
 void qlt_fc_port_added(struct scsi_qla_host *vha, fc_port_t *fcport)
 {
@@ -874,7 +890,12 @@ void qlt_fc_port_added(struct scsi_qla_host *vha, fc_port_t *fcport)
        spin_unlock_irqrestore(&ha->hardware_lock, flags);
 }
 
-void qlt_fc_port_deleted(struct scsi_qla_host *vha, fc_port_t *fcport)
+/*
+ * max_gen - specifies maximum session generation
+ * at which this deletion requestion is still valid
+ */
+void
+qlt_fc_port_deleted(struct scsi_qla_host *vha, fc_port_t *fcport, int max_gen)
 {
        struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
        struct qla_tgt_sess *sess;
@@ -893,6 +914,15 @@ void qlt_fc_port_deleted(struct scsi_qla_host *vha, fc_port_t *fcport)
                return;
        }
 
+       if (max_gen - sess->generation < 0) {
+               ql_dbg(ql_dbg_tgt_mgt, vha, 0xf092,
+                   "Ignoring stale deletion request for se_sess %p / sess %p"
+                   " for port %8phC, req_gen %d, sess_gen %d\n",
+                   sess->se_sess, sess, sess->port_name, max_gen,
+                   sess->generation);
+               return;
+       }
+
        ql_dbg(ql_dbg_tgt_mgt, vha, 0xf008, "qla_tgt_fc_port_deleted %p", sess);
 
        sess->local = 1;
@@ -3971,7 +4001,7 @@ void qlt_logo_completion_handler(fc_port_t *fcport, int rc)
 {
        if (fcport->tgt_session) {
                if (rc != MBS_COMMAND_COMPLETE) {
-                       ql_dbg(ql_dbg_tgt_mgt, fcport->vha, 0xf088,
+                       ql_dbg(ql_dbg_tgt_mgt, fcport->vha, 0xf093,
                                "%s: se_sess %p / sess %p from"
                                " port %8phC loop_id %#04x s_id %02x:%02x:%02x"
                                " LOGO failed: %#x\n",
@@ -4100,6 +4130,7 @@ static int qlt_24xx_handle_els(struct scsi_qla_host *vha,
        struct imm_ntfy_from_isp *iocb)
 {
        struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
+       struct qla_hw_data *ha = vha->hw;
        struct qla_tgt_sess *sess = NULL;
        uint64_t wwn;
        port_id_t port_id;
@@ -4145,7 +4176,7 @@ static int qlt_24xx_handle_els(struct scsi_qla_host *vha,
                         * without acking, new one will get acked when session
                         * deletion completes.
                         */
-                       ql_log(ql_log_warn, sess->vha, 0xf089,
+                       ql_log(ql_log_warn, sess->vha, 0xf094,
                            "sess %p received double plogi.\n", sess);
 
                        qlt_swap_imm_ntfy_iocb(iocb, &sess->tm_iocb);
@@ -4202,7 +4233,7 @@ static int qlt_24xx_handle_els(struct scsi_qla_host *vha,
                                 * PLOGI could finish. Will force him to re-try,
                                 * while last one finishes.
                                 */
-                               ql_log(ql_log_warn, sess->vha, 0xf090,
+                               ql_log(ql_log_warn, sess->vha, 0xf095,
                                    "sess %p PRLI received, before plogi ack.\n",
                                    sess);
                                qlt_send_term_imm_notif(vha, iocb, 1);
@@ -4214,7 +4245,7 @@ static int qlt_24xx_handle_els(struct scsi_qla_host *vha,
                         * This shouldn't happen under normal circumstances,
                         * since we have deleted the old session during PLOGI
                         */
-                       ql_dbg(ql_dbg_tgt_mgt, vha, 0xf091,
+                       ql_dbg(ql_dbg_tgt_mgt, vha, 0xf096,
                            "PRLI (loop_id %#04x) for existing sess %p (loop_id %#04x)\n",
                            sess->loop_id, sess, iocb->u.isp24.nport_handle);
 
@@ -4225,7 +4256,14 @@ static int qlt_24xx_handle_els(struct scsi_qla_host *vha,
                        if (wd3_lo & BIT_7)
                                sess->conf_compl_supported = 1;
 
-                       res = 1;
+               }
+               res = 1; /* send notify ack */
+
+               /* Make session global (not used in fabric mode) */
+               if (ha->current_topology != ISP_CFG_F) {
+                       set_bit(LOOP_RESYNC_NEEDED, &vha->dpc_flags);
+                       set_bit(LOCAL_LOOP_UPDATE, &vha->dpc_flags);
+                       qla2xxx_wake_dpc(vha);
                } else {
                        /* todo: else - create sess here. */
                        res = 1; /* send notify ack */
index 13b3b0d9b819983b03f48245b3118013ee41560a..dfc60c78102d98908db381b860f29a6d87133131 100644 (file)
@@ -919,6 +919,8 @@ struct qla_tgt_sess {
 
        unsigned char logout_completed;
 
+       int generation;
+
        struct se_session *se_sess;
        struct scsi_qla_host *vha;
        struct qla_tgt *tgt;
@@ -1084,7 +1086,7 @@ extern int qlt_lport_register(void *, u64, u64, u64,
 extern void qlt_lport_deregister(struct scsi_qla_host *);
 extern void qlt_unreg_sess(struct qla_tgt_sess *);
 extern void qlt_fc_port_added(struct scsi_qla_host *, fc_port_t *);
-extern void qlt_fc_port_deleted(struct scsi_qla_host *, fc_port_t *);
+extern void qlt_fc_port_deleted(struct scsi_qla_host *, fc_port_t *, int);
 extern int __init qlt_init(void);
 extern void qlt_exit(void);
 extern void qlt_update_vp_map(struct scsi_qla_host *, int);
@@ -1161,5 +1163,6 @@ extern irqreturn_t qla83xx_msix_atio_q(int, void *);
 extern void qlt_83xx_iospace_config(struct qla_hw_data *);
 extern int qlt_free_qfull_cmds(struct scsi_qla_host *);
 extern void qlt_logo_completion_handler(fc_port_t *, int);
+extern void qlt_do_generation_tick(struct scsi_qla_host *, int *);
 
 #endif /* __QLA_TARGET_H */