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 new scan module parameter value 'manual', which works like 'none', but can be overriden by setting the 'rescan' value from scsi_scan_target to 'SCSI_SCAN_MANUAL'. And it updates all relevant callers to set the 'rescan' value to 'SCSI_SCAN_MANUAL' if invoked via the 'scan' option in sysfs. Signed-off-by: Hannes Reinecke <[email protected]> --- drivers/scsi/scsi_scan.c | 25 ++++++++++++++++++------- drivers/scsi/scsi_sysfs.c | 3 ++- drivers/scsi/scsi_transport_fc.c | 3 ++- drivers/scsi/scsi_transport_iscsi.c | 2 +- drivers/scsi/scsi_transport_sas.c | 4 ++-- include/scsi/scsi_device.h | 6 ++++++ 6 files changed, 31 insertions(+), 12 deletions(-) diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 97074c9..54dc517 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -96,10 +96,13 @@ 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[7] = 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, manual, or none. " + "Setting to 'manual' disables automatic scanning, but allows " + "for manual device scan via the 'scan' sysfs attribute."); static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18; @@ -1040,7 +1043,8 @@ static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, * @lun: LUN of target device * @bflagsp: store bflags here if not NULL * @sdevp: probe the LUN corresponding to this scsi_device - * @rescan: if nonzero skip some code only needed on first scan + * @rescan: if greater than SCSI_SCAN_NONE skip some code only + * needed on first scan * @hostdata: passed to scsi_alloc_sdev() * * Description: @@ -1069,7 +1073,7 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget, */ sdev = scsi_device_lookup_by_target(starget, lun); if (sdev) { - if (rescan || !scsi_device_created(sdev)) { + if (rescan > SCSI_SCAN_NONE || !scsi_device_created(sdev)) { SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, "scsi scan: device exists on %s\n", dev_name(&sdev->sdev_gendev))); @@ -1604,7 +1608,9 @@ 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; SCSI_SCAN_NONE for no rescan, + * SCSI_SCAN_RESCAN to rescan existing LUNs, and SCSI_SCAN_MANUAL + * to force scanning even if 'scan=manual' is set. * * Description: * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, @@ -1621,6 +1627,10 @@ void scsi_scan_target(struct device *parent, unsigned int channel, if (strncmp(scsi_scan_type, "none", 4) == 0) return; + if (rescan < SCSI_SCAN_MANUAL && + strncmp(scsi_scan_type, "manual", 6) == 0) + return; + mutex_lock(&shost->scan_mutex); if (!shost->async_scan) scsi_complete_async_scans(); @@ -1844,7 +1854,8 @@ 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, "manual", 6) == 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..3b2045f 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -143,7 +143,8 @@ 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, + SCSI_SCAN_MANUAL); return res; } diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 8a88226..3482a55 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -2110,7 +2110,8 @@ 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, + SCSI_SCAN_MANUAL); return; } } diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 4414816..f4c16dc 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, SCSI_SCAN_MANUAL); } user_scan_exit: diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c index b6f958193..d8d38e6 100644 --- a/drivers/scsi/scsi_transport_sas.c +++ b/drivers/scsi/scsi_transport_sas.c @@ -1739,8 +1739,8 @@ 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); + scsi_scan_target(&rphy->dev, 0, rphy->scsi_target_id, + lun, SCSI_SCAN_MANUAL); } } mutex_unlock(&sas_host->lock); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index c067019..f954272 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -50,6 +50,12 @@ enum scsi_device_state { SDEV_CREATED_BLOCK, /* same as above but for created devices */ }; +enum scsi_scan_mode { + SCSI_SCAN_NONE = 0, + SCSI_SCAN_RESCAN, + SCSI_SCAN_MANUAL, +}; + enum scsi_device_event { SDEV_EVT_MEDIA_CHANGE = 1, /* media has changed */ SDEV_EVT_INQUIRY_CHANGE_REPORTED, /* 3F 03 UA reported */ -- 1.8.5.6 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
