diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b3a6187..8129889 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1393,6 +1393,11 @@ running once the system is up. scsi_logging= [SCSI] + scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are + discovered. async scans them in kernel threads, + allowing boot to proceed. none ignores them, expecting + user space to do the scan. + selinux [SELINUX] Disable or enable SELinux at boot time. Format: { "0" | "1" } See security/selinux/Kconfig help text. diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig index a480a37..63c2710 100644 --- a/drivers/scsi/Kconfig +++ b/drivers/scsi/Kconfig @@ -209,6 +209,23 @@ config SCSI_LOGGING there should be no noticeable performance impact as long as you have logging turned off. +config SCSI_SCAN_ASYNC + bool "Asynchronous SCSI scanning" + depends on SCSI + help + The SCSI subsystem can probe for devices while the rest of the + system continues booting, and even probe devices on different + busses in parallel, leading to a significant speed-up. + If you have built SCSI as modules, enabling this option can + be a problem as the devices may not have been found by the + time your system expects them to have been. You can load the + scsi_wait_scan module to ensure that all scans have completed. + If you build your SCSI drivers into the kernel, then everything + will work fine if you say Y here. + + You can override this choice by specifying scsi_mod.scan="sync" + or "async" on the kernel's command line. + menu "SCSI Transport Attributes" depends on SCSI diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile index 81803a1..fbd88cb 100644 --- a/drivers/scsi/Makefile +++ b/drivers/scsi/Makefile @@ -149,6 +149,8 @@ obj-$(CONFIG_CHR_DEV_SCH) += ch.o # This goes last, so that "real" scsi devices probe earlier obj-$(CONFIG_SCSI_DEBUG) += scsi_debug.o +obj-$(CONFIG_SCSI) += scsi_wait_scan.o + scsi_mod-y += scsi.o hosts.o scsi_ioctl.o constants.o \ scsicam.o scsi_error.o scsi_lib.o \ scsi_scan.o scsi_sysfs.o \ diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 584fe5d..3c185af 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -83,6 +83,7 @@ MODULE_PARM_DESC(ql2xprocessrscn, static int qla2xxx_slave_configure(struct scsi_device * device); static int qla2xxx_slave_alloc(struct scsi_device *); static void qla2xxx_slave_destroy(struct scsi_device *); +static int qla2xxx_scan_finished(struct Scsi_Host *); static int qla2x00_queuecommand(struct scsi_cmnd *cmd, void (*fn)(struct scsi_cmnd *)); static int qla24xx_queuecommand(struct scsi_cmnd *cmd, @@ -111,6 +112,7 @@ static struct scsi_host_template qla2x00 .slave_alloc = qla2xxx_slave_alloc, .slave_destroy = qla2xxx_slave_destroy, + .scan_finished = qla2x00_scan_finished, .change_queue_depth = qla2x00_change_queue_depth, .change_queue_type = qla2x00_change_queue_type, .this_id = -1, @@ -1321,6 +1323,20 @@ qla24xx_disable_intrs(scsi_qla_host_t *h spin_unlock_irqrestore(&ha->hardware_lock, flags); } +static int qla2x00_scan_finished(struct Scsi_Host *shost, unsigned long time) +{ + scsi_qla_host_t *ha = (scsi_qla_host_t *)shost->hostdata; + + if (time > ha->loop_reset_delay * HZ) + return 1; + + qla2x00_check_fabric_devices(ha); + + if (ha->device_flags & (DFLG_NO_CABLE | DFLG_FABRIC_DEVICES)) + return 1; + return !(ha->device_flags & SWITCH_FOUND); +} + /* * PCI driver interface */ @@ -1330,8 +1346,7 @@ int qla2x00_probe_one(struct pci_dev *pd device_reg_t __iomem *reg; struct Scsi_Host *host; scsi_qla_host_t *ha; - unsigned long flags = 0; - unsigned long wait_switch = 0; + unsigned long flags; char pci_info[20]; char fw_str[30]; fc_port_t *fcport; @@ -1591,22 +1606,6 @@ #endif ha->isp_ops.enable_intrs(ha); - /* v2.19.5b6 */ - /* - * Wait around max loop_reset_delay secs for the devices to come - * on-line. We don't want Linux scanning before we are ready. - * - */ - for (wait_switch = jiffies + (ha->loop_reset_delay * HZ); - time_before(jiffies,wait_switch) && - !(ha->device_flags & (DFLG_NO_CABLE | DFLG_FABRIC_DEVICES)) - && (ha->device_flags & SWITCH_FOUND) ;) { - - qla2x00_check_fabric_devices(ha); - - msleep(10); - } - pci_set_drvdata(pdev, ha); ha->flags.init_done = 1; num_hosts++; @@ -1614,6 +1613,7 @@ #endif ret = scsi_add_host(host, &pdev->dev); if (ret) goto probe_failed; + scsi_scan_host(host); qla2x00_alloc_sysfs_attr(ha); diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 27c4827..ab833c0 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -49,6 +49,9 @@ static inline void scsi_log_completion(s { }; #endif +/* scsi_scan.c */ +int scsi_complete_async_scans(void); + /* scsi_devinfo.c */ extern int scsi_get_device_flags(struct scsi_device *sdev, const unsigned char *vendor, diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 1a5474b..efd130b 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -30,7 +30,9 @@ #include #include #include #include -#include +#include +#include +#include #include #include @@ -88,6 +90,17 @@ module_param_named(max_luns, max_scsi_lu MODULE_PARM_DESC(max_luns, "last scsi LUN (should be between 1 and 2^32-1)"); +#ifdef CONFIG_SCSI_SCAN_ASYNC +#define SCSI_SCAN_TYPE_DEFAULT "async" +#else +#define SCSI_SCAN_TYPE_DEFAULT "sync" +#endif + +static char scsi_scan_type[6] = 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"); + /* * max_scsi_report_luns: the maximum number of LUNS that will be * returned from the REPORT LUNS command. 8 times this value must @@ -109,6 +122,68 @@ MODULE_PARM_DESC(inq_timeout, "Timeout (in seconds) waiting for devices to answer INQUIRY." " Default is 5. Some non-compliant devices need more."); +static DEFINE_SPINLOCK(async_scan_lock); +static LIST_HEAD(scanning_hosts); + +struct async_scan_data { + struct list_head list; + struct Scsi_Host *shost; + struct completion prev_finished; +}; + +/** + * scsi_complete_async_scans - Wait for asynchronous scans to complete + * + * Asynchronous scans add themselves to the scanning_hosts list. Once + * that list is empty, we know that the scans are complete. Rather than + * waking up periodically to check the state of the list, we pretend to be + * a scanning task by adding ourselves at the end of the list and going to + * sleep. When the task before us wakes us up, we take ourselves off the + * list and return. + */ +int scsi_complete_async_scans(void) +{ + struct async_scan_data *data; + + do { + if (list_empty(&scanning_hosts)) + return 0; + /* If we can't get memory immediately, that's OK. Just + * sleep a little. Even if we never get memory, the async + * scans will finish eventually. + */ + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + msleep(1); + } while (!data); + + data->shost = NULL; + init_completion(&data->prev_finished); + + spin_lock(&async_scan_lock); + /* Check that there's still somebody else on the list */ + if (list_empty(&scanning_hosts)) + goto done; + list_add_tail(&data->list, &scanning_hosts); + spin_unlock(&async_scan_lock); + + printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); + wait_for_completion(&data->prev_finished); + + spin_lock(&async_scan_lock); + list_del(&data->list); + done: + spin_unlock(&async_scan_lock); + + kfree(data); + return 0; +} + +#ifdef MODULE +/* Only exported for the benefit of scsi_wait_scan */ +EXPORT_SYMBOL_GPL(scsi_complete_async_scans); +#endif + /** * scsi_unlock_floptical - unlock device via a special MODE SENSE command * @sdev: scsi device to send command to @@ -629,7 +704,8 @@ static int scsi_probe_lun(struct scsi_de * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized **/ -static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags) +static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, + int *bflags, int async) { /* * XXX do not save the inquiry, since it can change underneath us, @@ -802,7 +878,7 @@ static int scsi_add_lun(struct scsi_devi * register it and tell the rest of the kernel * about it. */ - if (scsi_sysfs_add_sdev(sdev) != 0) + if (!async && scsi_sysfs_add_sdev(sdev) != 0) return SCSI_SCAN_NO_RESPONSE; return SCSI_SCAN_LUN_PRESENT; @@ -914,7 +990,7 @@ static int scsi_probe_and_add_lun(struct goto out_free_result; } - res = scsi_add_lun(sdev, result, &bflags); + res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); if (res == SCSI_SCAN_LUN_PRESENT) { if (bflags & BLIST_KEY) { sdev->lockable = 0; @@ -1427,6 +1503,12 @@ void scsi_scan_target(struct device *par { struct Scsi_Host *shost = dev_to_shost(parent); + if (strncmp(scsi_scan_type, "none", 4) == 0) + return; + + if (!shost->async_scan) + scsi_complete_async_scans(); + mutex_lock(&shost->scan_mutex); if (scsi_host_scan_allowed(shost)) __scsi_scan_target(parent, channel, id, lun, rescan); @@ -1472,6 +1554,9 @@ int scsi_scan_host_selected(struct Scsi_ "%s: <%u:%u:%u>\n", __FUNCTION__, channel, id, lun)); + if (!shost->async_scan) + scsi_complete_async_scans(); + if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || ((id != SCAN_WILD_CARD) && (id > shost->max_id)) || ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun))) @@ -1492,14 +1577,140 @@ int scsi_scan_host_selected(struct Scsi_ return 0; } +static void scsi_sysfs_add_devices(struct Scsi_Host *shost) +{ + struct scsi_device *sdev; + shost_for_each_device(sdev, shost) { + if (scsi_sysfs_add_sdev(sdev) != 0) + scsi_destroy_sdev(sdev); + } +} + +/** + * scsi_prep_async_scan - prepare for an async scan + * @shost: the host which will be scanned + * Returns: a cookie to be passed to scsi_finish_async_scan() + * + * Tells the midlayer this host is going to do an asynchronous scan. + * It reserves the host's position in the scanning list and ensures + * that other asynchronous scans started after this one won't affect the + * ordering of the discovered devices. + */ +struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) +{ + struct async_scan_data *data; + + if (strncmp(scsi_scan_type, "sync", 4) == 0) + return NULL; + + if (shost->async_scan) { + printk("%s called twice for host %d", __FUNCTION__, + shost->host_no); + dump_stack(); + return NULL; + } + + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + goto err; + data->shost = scsi_host_get(shost); + if (!data->shost) + goto err; + init_completion(&data->prev_finished); + + spin_lock(&async_scan_lock); + shost->async_scan = 1; + if (list_empty(&scanning_hosts)) + complete(&data->prev_finished); + list_add_tail(&data->list, &scanning_hosts); + spin_unlock(&async_scan_lock); + + return data; + + err: + kfree(data); + return NULL; +} + +/** + * scsi_finish_async_scan - asynchronous scan has finished + * @data: cookie returned from earlier call to scsi_prep_async_scan() + * + * All the devices currently attached to this host have been found. + * This function announces all the devices it has found to the rest + * of the system. + */ +void scsi_finish_async_scan(struct async_scan_data *data) +{ + struct Scsi_Host *shost; + + if (!data) + return; + + shost = data->shost; + if (!shost->async_scan) { + printk("%s called twice for host %d", __FUNCTION__, + shost->host_no); + dump_stack(); + return; + } + + wait_for_completion(&data->prev_finished); + + scsi_sysfs_add_devices(shost); + + spin_lock(&async_scan_lock); + shost->async_scan = 0; + list_del(&data->list); + if (!list_empty(&scanning_hosts)) { + struct async_scan_data *next = list_entry(scanning_hosts.next, + struct async_scan_data, list); + complete(&next->prev_finished); + } + spin_unlock(&async_scan_lock); + + scsi_host_put(shost); + kfree(data); +} + +static void do_scsi_scan_host(struct Scsi_Host *shost) +{ + if (shost->hostt->scan_finished) { + unsigned long start = jiffies; + while (!shost->hostt->scan_finished(shost, jiffies - start)) + msleep(10); + } else { + scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, + SCAN_WILD_CARD, 0); + } +} + +static int do_scan_async(void *_data) +{ + struct async_scan_data *data = _data; + do_scsi_scan_host(data->shost); + scsi_finish_async_scan(data); + return 0; +} + /** * scsi_scan_host - scan the given adapter * @shost: adapter to scan **/ void scsi_scan_host(struct Scsi_Host *shost) { - scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, - SCAN_WILD_CARD, 0); + struct async_scan_data *data; + + if (strncmp(scsi_scan_type, "none", 4) == 0) + return; + + data = scsi_prep_async_scan(shost); + if (!data) { + do_scsi_scan_host(shost); + return; + } + + kthread_run(do_scan_async, data, "scsi_scan_%d", shost->host_no); } EXPORT_SYMBOL(scsi_scan_host); diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 895d212..0f75a48 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -223,13 +223,13 @@ extern struct scsi_device *__scsi_iterat struct scsi_device *); /** - * shost_for_each_device - iterate over all devices of a host - * @sdev: iterator - * @host: host whiches devices we want to iterate over + * shost_for_each_device - iterate over all devices of a host + * @sdev: the &struct scsi_device to use as a cursor + * @shost: the &struct scsi_host to iterate over * - * This traverses over each devices of @shost. The devices have - * a reference that must be released by scsi_host_put when breaking - * out of the loop. + * Iterator that returns each device attached to @shost. This loop + * takes a reference on each device and releases it at the end. If + * you break out of the loop, you must call scsi_device_put(sdev). */ #define shost_for_each_device(sdev, shost) \ for ((sdev) = __scsi_iterate_devices((shost), NULL); \ @@ -237,17 +237,17 @@ #define shost_for_each_device(sdev, shos (sdev) = __scsi_iterate_devices((shost), (sdev))) /** - * __shost_for_each_device - iterate over all devices of a host (UNLOCKED) - * @sdev: iterator - * @host: host whiches devices we want to iterate over + * __shost_for_each_device - iterate over all devices of a host (UNLOCKED) + * @sdev: the &struct scsi_device to use as a cursor + * @shost: the &struct scsi_host to iterate over * - * This traverses over each devices of @shost. It does _not_ take a - * reference on the scsi_device, thus it the whole loop must be protected - * by shost->host_lock. + * Iterator that returns each device attached to @shost. It does _not_ + * take a reference on the scsi_device, so the whole loop must be + * protected by shost->host_lock. * - * Note: The only reason why drivers would want to use this is because - * they're need to access the device list in irq context. Otherwise you - * really want to use shost_for_each_device instead. + * Note: The only reason to use this is because you need to access the + * device list in interrupt context. Otherwise you really want to use + * shost_for_each_device instead. */ #define __shost_for_each_device(sdev, shost) \ list_for_each_entry((sdev), &((shost)->__devices), siblings) diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index de6ce54..c5e78d9 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -240,6 +240,17 @@ #endif void (* target_destroy)(struct scsi_target *); /* + * If a host has the ability to discover targets on its own instead + * of scanning the entire bus, it can fill in this function and + * call scsi_scan_host(). This function will be called periodically + * until it returns 1 with the scsi_host and the elapsed time of + * the scan in jiffies. + * + * Status: OPTIONAL + */ + int (* scan_finished)(struct Scsi_Host *, unsigned long); + + /* * fill in this function to allow the queue depth of this host * to be changeable (on a per device basis). returns either * the current queue depth setting (may be different from what @@ -552,6 +563,9 @@ struct Scsi_Host { */ unsigned int host_blocked; + /* Asynchronous scan in progress */ + unsigned async_scan:1; + /* * Value host_blocked counts down from */