diff options
Diffstat (limited to 'drivers/usb/storage/scsiglue.c')
| -rw-r--r-- | drivers/usb/storage/scsiglue.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index d34dc9f417f..4837524eada 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; } |