On larger installations it is useful to disable automatic LUN scanning, and only add the required LUNs via udev rules. This can speed up bootup dramatically.
This patch introduces a scan_type 'disabled', which work like 'none', but can be overriden by setting the 'rescan' value from scsi_scan_target to '2'. And it updates all relevant callers to set the 'rescan' value to '2' if invoked via the 'scan' option in sysfs. Signed-off-by: Hannes Reinecke <h...@suse.de> --- drivers/scsi/scsi_scan.c | 17 ++++++++++++----- drivers/scsi/scsi_sysfs.c | 2 +- drivers/scsi/scsi_transport_fc.c | 2 +- drivers/scsi/scsi_transport_iscsi.c | 2 +- drivers/scsi/scsi_transport_sas.c | 2 +- 5 files changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 97074c9..929204b 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -96,10 +96,11 @@ MODULE_PARM_DESC(max_luns, #define SCSI_SCAN_TYPE_DEFAULT "sync" #endif -char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT; +char scsi_scan_type[9] = SCSI_SCAN_TYPE_DEFAULT; -module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO); -MODULE_PARM_DESC(scan, "sync, async or none"); +module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), + S_IRUGO|S_IWUSR); +MODULE_PARM_DESC(scan, "sync, async, disabled, or none"); static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18; @@ -1604,7 +1605,9 @@ static void __scsi_scan_target(struct device *parent, unsigned int channel, * @channel: channel to scan * @id: target id to scan * @lun: Specific LUN to scan or SCAN_WILD_CARD - * @rescan: passed to LUN scanning routines + * @rescan: passed to LUN scanning routines; 0 for no rescan, 1 to rescan + * existing LUNs, and 2 to override any 'scan_disabled' setting + * from the host. * * Description: * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, @@ -1621,6 +1624,9 @@ void scsi_scan_target(struct device *parent, unsigned int channel, if (strncmp(scsi_scan_type, "none", 4) == 0) return; + if (rescan < 2 && strncmp(scsi_scan_type, "disabled", 8) == 0) + return; + mutex_lock(&shost->scan_mutex); if (!shost->async_scan) scsi_complete_async_scans(); @@ -1844,7 +1850,8 @@ void scsi_scan_host(struct Scsi_Host *shost) { struct async_scan_data *data; - if (strncmp(scsi_scan_type, "none", 4) == 0) + if (strncmp(scsi_scan_type, "none", 4) == 0 || + strncmp(scsi_scan_type, "disabled", 8) == 0) return; if (scsi_autopm_get_host(shost) < 0) return; diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 92ffd24..d805d55 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -143,7 +143,7 @@ static int scsi_scan(struct Scsi_Host *shost, const char *str) if (shost->transportt->user_scan) res = shost->transportt->user_scan(shost, channel, id, lun); else - res = scsi_scan_host_selected(shost, channel, id, lun, 1); + res = scsi_scan_host_selected(shost, channel, id, lun, 2); return res; } diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 8a88226..018b2da 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -2110,7 +2110,7 @@ fc_user_scan_tgt(struct Scsi_Host *shost, uint channel, uint id, u64 lun) if ((channel == rport->channel) && (id == rport->scsi_target_id)) { spin_unlock_irqrestore(shost->host_lock, flags); - scsi_scan_target(&rport->dev, channel, id, lun, 1); + scsi_scan_target(&rport->dev, channel, id, lun, 2); return; } } diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 4414816..2941598 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -1819,7 +1819,7 @@ static int iscsi_user_scan_session(struct device *dev, void *data) (scan_data->id == SCAN_WILD_CARD || scan_data->id == id)) scsi_scan_target(&session->dev, 0, id, - scan_data->lun, 1); + scan_data->lun, 2); } user_scan_exit: diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c index deb3fde..1e0664f 100644 --- a/drivers/scsi/scsi_transport_sas.c +++ b/drivers/scsi/scsi_transport_sas.c @@ -1740,7 +1740,7 @@ static int sas_user_scan(struct Scsi_Host *shost, uint channel, if ((channel == SCAN_WILD_CARD || channel == 0) && (id == SCAN_WILD_CARD || id == rphy->scsi_target_id)) { scsi_scan_target(&rphy->dev, 0, - rphy->scsi_target_id, lun, 1); + rphy->scsi_target_id, lun, 2); } } mutex_unlock(&sas_host->lock); -- 1.8.5.6 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html