#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>
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;
+}
+
+#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
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)
{
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;
}
* 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);
sdev->no_uld_attach = 1;
switch (sdev->type = (inq_result[0] & 0x1f)) {
+ case TYPE_RBC:
+ /* RBC 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;
+ /* fall through */
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:
+ /* 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;
+ /* fall through */
+ case TYPE_WORM:
sdev->writeable = 0;
break;
default:
* 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;
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;
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.openpandora.org / pandora-kernel.git / blobdiff