diff options
Diffstat (limited to 'drivers/scsi/device_handler/scsi_dh_alua.c')
| -rw-r--r-- | drivers/scsi/device_handler/scsi_dh_alua.c | 81 |
1 files changed, 73 insertions, 8 deletions
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index efa8c0381476..37d06f993b76 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -88,6 +88,7 @@ struct alua_dh_data { struct scsi_device *sdev; int init_error; struct mutex init_mutex; + bool disabled; }; struct alua_queue_data { @@ -517,7 +518,8 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) int len, k, off, bufflen = ALUA_RTPG_SIZE; int group_id_old, state_old, pref_old, valid_states_old; unsigned char *desc, *buff; - unsigned err, retval; + unsigned err; + int retval; unsigned int tpg_desc_tbl_off; unsigned char orig_transition_tmo; unsigned long flags; @@ -562,13 +564,15 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) kfree(buff); return SCSI_DH_OK; } - if (!scsi_sense_valid(&sense_hdr)) { + if (retval < 0 || !scsi_sense_valid(&sense_hdr)) { sdev_printk(KERN_INFO, sdev, "%s: rtpg failed, result %d\n", ALUA_DH_NAME, retval); kfree(buff); - if (driver_byte(retval) == DRIVER_ERROR) + if (retval < 0) return SCSI_DH_DEV_TEMP_BUSY; + if (host_byte(retval) == DID_NO_CONNECT) + return SCSI_DH_RES_TEMP_UNAVAIL; return SCSI_DH_IO; } @@ -791,11 +795,11 @@ static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) retval = submit_stpg(sdev, pg->group_id, &sense_hdr); if (retval) { - if (!scsi_sense_valid(&sense_hdr)) { + if (retval < 0 || !scsi_sense_valid(&sense_hdr)) { sdev_printk(KERN_INFO, sdev, "%s: stpg failed, result %d", ALUA_DH_NAME, retval); - if (driver_byte(retval) == DRIVER_ERROR) + if (retval < 0) return SCSI_DH_DEV_TEMP_BUSY; } else { sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n", @@ -807,6 +811,51 @@ static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) return SCSI_DH_RETRY; } +static bool alua_rtpg_select_sdev(struct alua_port_group *pg) +{ + struct alua_dh_data *h; + struct scsi_device *sdev = NULL; + + lockdep_assert_held(&pg->lock); + if (WARN_ON(!pg->rtpg_sdev)) + return false; + + /* + * RCU protection isn't necessary for dh_list here + * as we hold pg->lock, but for access to h->pg. + */ + rcu_read_lock(); + list_for_each_entry_rcu(h, &pg->dh_list, node) { + if (!h->sdev) + continue; + if (h->sdev == pg->rtpg_sdev) { + h->disabled = true; + continue; + } + if (rcu_dereference(h->pg) == pg && + !h->disabled && + !scsi_device_get(h->sdev)) { + sdev = h->sdev; + break; + } + } + rcu_read_unlock(); + + if (!sdev) { + pr_warn("%s: no device found for rtpg\n", + (pg->device_id_len ? + (char *)pg->device_id_str : "(nameless PG)")); + return false; + } + + sdev_printk(KERN_INFO, sdev, "rtpg retry on different device\n"); + + scsi_device_put(pg->rtpg_sdev); + pg->rtpg_sdev = sdev; + + return true; +} + static void alua_rtpg_work(struct work_struct *work) { struct alua_port_group *pg = @@ -815,6 +864,7 @@ static void alua_rtpg_work(struct work_struct *work) LIST_HEAD(qdata_list); int err = SCSI_DH_OK; struct alua_queue_data *qdata, *tmp; + struct alua_dh_data *h; unsigned long flags; spin_lock_irqsave(&pg->lock, flags); @@ -848,9 +898,18 @@ static void alua_rtpg_work(struct work_struct *work) } err = alua_rtpg(sdev, pg); spin_lock_irqsave(&pg->lock, flags); - if (err == SCSI_DH_RETRY || pg->flags & ALUA_PG_RUN_RTPG) { + + /* If RTPG failed on the current device, try using another */ + if (err == SCSI_DH_RES_TEMP_UNAVAIL && + alua_rtpg_select_sdev(pg)) + err = SCSI_DH_IMM_RETRY; + + if (err == SCSI_DH_RETRY || err == SCSI_DH_IMM_RETRY || + pg->flags & ALUA_PG_RUN_RTPG) { pg->flags &= ~ALUA_PG_RUNNING; - if (!pg->interval && !(pg->flags & ALUA_PG_RUN_RTPG)) + if (err == SCSI_DH_IMM_RETRY) + pg->interval = 0; + else if (!pg->interval && !(pg->flags & ALUA_PG_RUN_RTPG)) pg->interval = ALUA_RTPG_RETRY_DELAY; pg->flags |= ALUA_PG_RUN_RTPG; spin_unlock_irqrestore(&pg->lock, flags); @@ -878,6 +937,12 @@ static void alua_rtpg_work(struct work_struct *work) } list_splice_init(&pg->rtpg_list, &qdata_list); + /* + * We went through an RTPG, for good or bad. + * Re-enable all devices for the next attempt. + */ + list_for_each_entry(h, &pg->dh_list, node) + h->disabled = false; pg->rtpg_sdev = NULL; spin_unlock_irqrestore(&pg->lock, flags); @@ -962,6 +1027,7 @@ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) int err = SCSI_DH_DEV_UNSUPP, tpgs; mutex_lock(&h->init_mutex); + h->disabled = false; tpgs = alua_check_tpgs(sdev); if (tpgs != TPGS_MODE_NONE) err = alua_check_vpd(sdev, h, tpgs); @@ -1080,7 +1146,6 @@ static void alua_check(struct scsi_device *sdev, bool force) return; } rcu_read_unlock(); - alua_rtpg_queue(pg, sdev, NULL, force); kref_put(&pg->kref, release_port_group); } |