scsi: split scsi_nonblockable_ioctl

The calling conventions for this function are bad as it could return
-ENODEV both for a device not currently online and a not recognized ioctl.

Add a new scsi_ioctl_block_when_processing_errors function that wraps
scsi_block_when_processing_errors with the a special case for the
SG_SCSI_RESET ioctl command, and handle the SG_SCSI_RESET case itself
in scsi_ioctl.  All callers of scsi_ioctl now must call the above helper
to check for the EH state, so that the ioctl handler itself doesn't
have to.

Reported-by: Robert Elliott <Elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

1 files changed, 15 insertions, 18 deletions

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 7c55cacceb7c..b14f64cb9724 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1071,16 +1071,6 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 		if (atomic_read(&sdp->detaching))
 			return -ENODEV;
 		return put_user(sdp->device->host->hostt->emulated, ip);
-	case SG_SCSI_RESET:
-		if (atomic_read(&sdp->detaching))
-			return -ENODEV;
-		if (filp->f_flags & O_NONBLOCK) {
-			if (scsi_host_in_recovery(sdp->device->host))
-				return -EBUSY;
-		} else if (!scsi_block_when_processing_errors(sdp->device))
-			return -EBUSY;
-
-		return scsi_ioctl_reset(sdp->device, ip);
 	case SCSI_IOCTL_SEND_COMMAND:
 		if (atomic_read(&sdp->detaching))
 			return -ENODEV;
@@ -1100,13 +1090,6 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 			return result;
 		sdp->sgdebug = (char) val;
 		return 0;
-	case SCSI_IOCTL_GET_IDLUN:
-	case SCSI_IOCTL_GET_BUS_NUMBER:
-	case SCSI_IOCTL_PROBE_HOST:
-	case SG_GET_TRANSFORM:
-		if (atomic_read(&sdp->detaching))
-			return -ENODEV;
-		return scsi_ioctl(sdp->device, cmd_in, p);
 	case BLKSECTGET:
 		return put_user(max_sectors_bytes(sdp->device->request_queue),
 				ip);
@@ -1122,11 +1105,25 @@ sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
 		return blk_trace_startstop(sdp->device->request_queue, 0);
 	case BLKTRACETEARDOWN:
 		return blk_trace_remove(sdp->device->request_queue);
+	case SCSI_IOCTL_GET_IDLUN:
+	case SCSI_IOCTL_GET_BUS_NUMBER:
+	case SCSI_IOCTL_PROBE_HOST:
+	case SG_GET_TRANSFORM:
+	case SG_SCSI_RESET:
+		if (atomic_read(&sdp->detaching))
+			return -ENODEV;
+		break;
 	default:
 		if (read_only)
 			return -EPERM;	/* don't know so take safe approach */
-		return scsi_ioctl(sdp->device, cmd_in, p);
+		break;
 	}
+
+	result = scsi_ioctl_block_when_processing_errors(sdp->device,
+			cmd_in, filp->f_flags & O_NDELAY);
+	if (result)
+		return result;
+	return scsi_ioctl(sdp->device, cmd_in, p);
 }
 
 #ifdef CONFIG_COMPAT