#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/blkdev.h>
-#include <asm/semaphore.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/spinlock.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#define SCSI_TIMEOUT (2*HZ)
/*
- * Prefix values for the SCSI id's (stored in driverfs name field)
+ * Prefix values for the SCSI id's (stored in sysfs name field)
*/
#define SCSI_UID_SER_NUM 'S'
#define SCSI_UID_UNKNOWN 'Z'
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
"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
+ *
+ * When this function returns, any host which started scanning before
+ * this function was called will have finished its scan. Hosts which
+ * started scanning after this function was called may or may not have
+ * finished.
+ */
+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);
+ if (!list_empty(&scanning_hosts)) {
+ struct async_scan_data *next = list_entry(scanning_hosts.next,
+ struct async_scan_data, list);
+ complete(&next->prev_finished);
+ }
+ done:
+ spin_unlock(&async_scan_lock);
+
+ kfree(data);
+ return 0;
+}
+
+/* Only exported for the benefit of scsi_wait_scan */
+EXPORT_SYMBOL_GPL(scsi_complete_async_scans);
+
+#ifndef MODULE
+/*
+ * For async scanning we need to wait for all the scans to complete before
+ * trying to mount the root fs. Otherwise non-modular drivers may not be ready
+ * yet.
+ */
+late_initcall(scsi_complete_async_scans);
+#endif
+
/**
* scsi_unlock_floptical - unlock device via a special MODE SENSE command
* @sdev: scsi device to send command to
return found_starget;
}
+/**
+ * scsi_alloc_target - allocate a new or find an existing target
+ * @parent: parent of the target (need not be a scsi host)
+ * @channel: target channel number (zero if no channels)
+ * @id: target id number
+ *
+ * Return an existing target if one exists, provided it hasn't already
+ * gone into STARGET_DEL state, otherwise allocate a new target.
+ *
+ * The target is returned with an incremented reference, so the caller
+ * is responsible for both reaping and doing a last put
+ */
static struct scsi_target *scsi_alloc_target(struct device *parent,
int channel, uint id)
{
INIT_LIST_HEAD(&starget->siblings);
INIT_LIST_HEAD(&starget->devices);
starget->state = STARGET_RUNNING;
+ starget->scsi_level = SCSI_2;
retry:
spin_lock_irqsave(shost->host_lock, flags);
return NULL;
}
}
+ get_device(dev);
return starget;
found:
found_target->reap_ref++;
spin_unlock_irqrestore(shost->host_lock, flags);
- put_device(parent);
if (found_target->state != STARGET_DEL) {
+ put_device(parent);
kfree(starget);
return found_target;
}
goto retry;
}
-static void scsi_target_reap_usercontext(void *data)
+static void scsi_target_reap_usercontext(struct work_struct *work)
{
- struct scsi_target *starget = data;
+ struct scsi_target *starget =
+ container_of(work, struct scsi_target, ew.work);
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
unsigned long flags;
starget->state = STARGET_DEL;
spin_unlock_irqrestore(shost->host_lock, flags);
execute_in_process_context(scsi_target_reap_usercontext,
- starget, &starget->ew);
+ &starget->ew);
return;
}
* short INQUIRY), an abort here prevents any further use of the
* device, including spin up.
*
+ * On the whole, the best approach seems to be to assume the first
+ * 36 bytes are valid no matter what the device says. That's
+ * better than copying < 36 bytes to the inquiry-result buffer
+ * and displaying garbage for the Vendor, Product, or Revision
+ * strings.
+ */
+ if (sdev->inquiry_len < 36) {
+ printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
+ " using 36\n", sdev->inquiry_len);
+ sdev->inquiry_len = 36;
+ }
+
+ /*
* Related to the above issue:
*
* XXX Devices (disk or all?) should be sent a TEST UNIT READY,
/**
* scsi_add_lun - allocate and fully initialze a scsi_device
- * @sdevscan: holds information to be stored in the new scsi_device
- * @sdevnew: store the address of the newly allocated scsi_device
+ * @sdev: holds information to be stored in the new scsi_device
* @inq_result: holds the result of a previous INQUIRY to the LUN
* @bflags: black/white list flag
+ * @async: 1 if this device is being scanned asynchronously
*
* Description:
- * Allocate and initialize a scsi_device matching sdevscan. Optionally
- * set fields based on values in *@bflags. If @sdevnew is not
- * NULL, store the address of the new scsi_device in *@sdevnew (needed
- * when scanning a particular LUN).
+ * Initialize the scsi_device @sdev. Optionally set fields based
+ * on values in *@bflags.
*
* Return:
* 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, unsigned char *inq_result,
- int *bflags)
+ int *bflags, int async)
{
/*
* XXX do not save the inquiry, since it can change underneath us,
* scanning run at their own risk, or supply a user level program
* that can correctly scan.
*/
- sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
- if (sdev->inquiry == NULL) {
+
+ /*
+ * Copy at least 36 bytes of INQUIRY data, so that we don't
+ * dereference unallocated memory when accessing the Vendor,
+ * Product, and Revision strings. Badly behaved devices may set
+ * the INQUIRY Additional Length byte to a small value, indicating
+ * these strings are invalid, but often they contain plausible data
+ * nonetheless. It doesn't matter if the device sent < 36 bytes
+ * total, since scsi_probe_lun() initializes inq_result with 0s.
+ */
+ sdev->inquiry = kmemdup(inq_result,
+ max_t(size_t, sdev->inquiry_len, 36),
+ GFP_ATOMIC);
+ if (sdev->inquiry == NULL)
return SCSI_SCAN_NO_RESPONSE;
- }
- memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
sdev->vendor = (char *) (sdev->inquiry + 8);
sdev->model = (char *) (sdev->inquiry + 16);
sdev->rev = (char *) (sdev->inquiry + 32);
if (*bflags & BLIST_ISROM) {
- /*
- * It would be better to modify sdev->type, and set
- * sdev->removable; this can now be done since
- * print_inquiry has gone away.
- */
- inq_result[0] = TYPE_ROM;
- inq_result[1] |= 0x80; /* removable */
- } else if (*bflags & BLIST_NO_ULD_ATTACH)
- sdev->no_uld_attach = 1;
+ sdev->type = TYPE_ROM;
+ sdev->removable = 1;
+ } else {
+ sdev->type = (inq_result[0] & 0x1f);
+ sdev->removable = (inq_result[1] & 0x80) >> 7;
+ }
- switch (sdev->type = (inq_result[0] & 0x1f)) {
+ switch (sdev->type) {
+ case TYPE_RBC:
case TYPE_TAPE:
case TYPE_DISK:
case TYPE_PRINTER:
case TYPE_ENCLOSURE:
case TYPE_COMM:
case TYPE_RAID:
- case TYPE_RBC:
sdev->writeable = 1;
break;
- case TYPE_WORM:
case TYPE_ROM:
+ case TYPE_WORM:
sdev->writeable = 0;
break;
default:
printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
}
+ if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
+ /* RBC and MMC devices can return SCSI-3 compliance and yet
+ * still not support REPORT LUNS, so make them act as
+ * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
+ * specifically set */
+ if ((*bflags & BLIST_REPORTLUN2) == 0)
+ *bflags |= BLIST_NOREPORTLUN;
+ }
+
/*
* For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
* spec says: The device server is capable of supporting the
*/
sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
- sdev->removable = (0x80 & inq_result[1]) >> 7;
sdev->lockable = sdev->removable;
sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
- if (sdev->scsi_level >= SCSI_3 || (sdev->inquiry_len > 56 &&
- inq_result[56] & 0x04))
+ if (sdev->scsi_level >= SCSI_3 ||
+ (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
sdev->ppr = 1;
if (inq_result[7] & 0x60)
sdev->wdtr = 1;
sdev->inq_periph_qual, inq_result[2] & 0x07,
(inq_result[3] & 0x0f) == 1 ? " CCS" : "");
- /*
- * End sysfs code.
- */
-
if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
!(*bflags & BLIST_NOTQ))
sdev->tagged_supported = 1;
+
/*
* Some devices (Texel CD ROM drives) have handshaking problems
* when used with the Seagate controllers. borken is initialized
if ((*bflags & BLIST_BORKEN) == 0)
sdev->borken = 0;
+ if (*bflags & BLIST_NO_ULD_ATTACH)
+ sdev->no_uld_attach = 1;
+
/*
* Apparently some really broken devices (contrary to the SCSI
* standards) need to be selected without asserting ATN
if (*bflags & BLIST_SINGLELUN)
sdev->single_lun = 1;
-
sdev->use_10_for_rw = 1;
if (*bflags & BLIST_MS_SKIP_PAGE_08)
* 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;
sdev_printk(KERN_INFO, sdev,
"scsi scan: consider passing scsi_mod."
- "dev_flags=%s:%s:0x240 or 0x800240\n",
+ "dev_flags=%s:%s:0x240 or 0x1000240\n",
scsi_inq_str(vend, result, 8, 16),
scsi_inq_str(mod, result, 16, 32));
});
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;
* Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
* the integer: 0x0b030a04
**/
-static int scsilun_to_int(struct scsi_lun *scsilun)
+int scsilun_to_int(struct scsi_lun *scsilun)
{
int i;
unsigned int lun;
scsilun->scsi_lun[i + 1]) << (i * 8));
return lun;
}
+EXPORT_SYMBOL(scsilun_to_int);
/**
* int_to_scsilun: reverts an int into a scsi_lun
struct device *parent = &shost->shost_gendev;
struct scsi_target *starget;
+ if (strncmp(scsi_scan_type, "none", 4) == 0)
+ return ERR_PTR(-ENODEV);
+
+ if (!shost->async_scan)
+ scsi_complete_async_scans();
+
starget = scsi_alloc_target(parent, channel, id);
if (!starget)
return ERR_PTR(-ENOMEM);
- get_device(&starget->dev);
mutex_lock(&shost->scan_mutex);
if (scsi_host_scan_allowed(shost))
scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
if (!starget)
return;
- get_device(&starget->dev);
if (lun != SCAN_WILD_CARD) {
/*
* Scan for a specific host/chan/id/lun.
{
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);
"%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)))
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.
+ */
+static 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.
+ */
+static 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;
+ if (shost->hostt->scan_start)
+ shost->hostt->scan_start(shost);
+
+ 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);
if (sdev) {
sdev->sdev_gendev.parent = get_device(&starget->dev);
sdev->borken = 0;
- }
+ } else
+ scsi_target_reap(starget);
put_device(&starget->dev);
out:
mutex_unlock(&shost->scan_mutex);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff