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path: root/drivers/usb/storage/scsiglue.c
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Diffstat (limited to 'drivers/usb/storage/scsiglue.c')
-rw-r--r--drivers/usb/storage/scsiglue.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index d34dc9f417f0..4837524eada7 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -227,42 +227,42 @@ static int queuecommand(struct scsi_cmnd *srb,
***********************************************************************/
/* Command timeout and abort */
-/* This is always called with scsi_lock(host) held */
static int command_abort(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
US_DEBUGP("%s called\n", __FUNCTION__);
+ /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
+ * bits are protected by the host lock. */
+ scsi_lock(us_to_host(us));
+
/* Is this command still active? */
if (us->srb != srb) {
+ scsi_unlock(us_to_host(us));
US_DEBUGP ("-- nothing to abort\n");
return FAILED;
}
/* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
* a device reset isn't already in progress (to avoid interfering
- * with the reset). To prevent races with auto-reset, we must
- * stop any ongoing USB transfers while still holding the host
- * lock. */
+ * with the reset). Note that we must retain the host lock while
+ * calling usb_stor_stop_transport(); otherwise it might interfere
+ * with an auto-reset that begins as soon as we release the lock. */
set_bit(US_FLIDX_TIMED_OUT, &us->flags);
if (!test_bit(US_FLIDX_RESETTING, &us->flags)) {
set_bit(US_FLIDX_ABORTING, &us->flags);
usb_stor_stop_transport(us);
}
+ scsi_unlock(us_to_host(us));
/* Wait for the aborted command to finish */
wait_for_completion(&us->notify);
-
- /* Reacquire the lock and allow USB transfers to resume */
- clear_bit(US_FLIDX_ABORTING, &us->flags);
- clear_bit(US_FLIDX_TIMED_OUT, &us->flags);
return SUCCESS;
}
/* This invokes the transport reset mechanism to reset the state of the
* device */
-/* This is always called with scsi_lock(host) held */
static int device_reset(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
@@ -279,7 +279,6 @@ static int device_reset(struct scsi_cmnd *srb)
}
/* Simulate a SCSI bus reset by resetting the device's USB port. */
-/* This is always called with scsi_lock(host) held */
static int bus_reset(struct scsi_cmnd *srb)
{
struct us_data *us = host_to_us(srb->device->host);
@@ -291,7 +290,6 @@ static int bus_reset(struct scsi_cmnd *srb)
result = usb_stor_port_reset(us);
up(&(us->dev_semaphore));
- /* lock the host for the return */
return result < 0 ? FAILED : SUCCESS;
}