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, 3 insertions, 4 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 63c35ed3c88d..7d2e036c75c1 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -3376,11 +3376,10 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
 	 * may try and take the device offline, in which case all further
 	 * access to the device is prohibited.
 	 */
-	retval = scsi_nonblockable_ioctl(STp->device, cmd_in, p,
-					file->f_flags & O_NDELAY);
-	if (!scsi_block_when_processing_errors(STp->device) || retval != -ENODEV)
+	retval = scsi_ioctl_block_when_processing_errors(STp->device, cmd_in,
+			file->f_flags & O_NDELAY);
+	if (retval)
 		goto out;
-	retval = 0;
 
 	cmd_type = _IOC_TYPE(cmd_in);
 	cmd_nr = _IOC_NR(cmd_in);