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, 13 insertions, 34 deletions

diff --git a/drivers/scsi/scsi_ioctl.c b/drivers/scsi/scsi_ioctl.c
index 5ddc08f39987..712f159ebb69 100644
--- a/drivers/scsi/scsi_ioctl.c
+++ b/drivers/scsi/scsi_ioctl.c
@@ -200,19 +200,6 @@ int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 {
 	char scsi_cmd[MAX_COMMAND_SIZE];
 
-	/* No idea how this happens.... */
-	if (!sdev)
-		return -ENXIO;
-
-	/*
-	 * If we are in the middle of error recovery, don't let anyone
-	 * else try and use this device.  Also, if error recovery fails, it
-	 * may try and take the device offline, in which case all further
-	 * access to the device is prohibited.
-	 */
-	if (!scsi_block_when_processing_errors(sdev))
-		return -ENODEV;
-
 	/* Check for deprecated ioctls ... all the ioctls which don't
 	 * follow the new unique numbering scheme are deprecated */
 	switch (cmd) {
@@ -273,6 +260,8 @@ int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 				     START_STOP_TIMEOUT, NORMAL_RETRIES);
         case SCSI_IOCTL_GET_PCI:
                 return scsi_ioctl_get_pci(sdev, arg);
+	case SG_SCSI_RESET:
+		return scsi_ioctl_reset(sdev, arg);
 	default:
 		if (sdev->host->hostt->ioctl)
 			return sdev->host->hostt->ioctl(sdev, cmd, arg);
@@ -281,30 +270,20 @@ int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 }
 EXPORT_SYMBOL(scsi_ioctl);
 
-/**
- * scsi_nonblockable_ioctl() - Handle SG_SCSI_RESET
- * @sdev: scsi device receiving ioctl
- * @cmd: Must be SC_SCSI_RESET
- * @arg: pointer to int containing SG_SCSI_RESET_{DEVICE,TARGET,BUS,HOST}
- *       possibly OR-ed with SG_SCSI_RESET_NO_ESCALATE
- * @ndelay: file mode O_NDELAY flag
+/*
+ * We can process a reset even when a device isn't fully operable.
  */
-int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
-			    void __user *arg, int ndelay)
+int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
+		bool ndelay)
 {
-	/* The first set of iocts may be executed even if we're doing
-	 * error processing, as long as the device was opened
-	 * non-blocking */
-	if (ndelay) {
+	if (cmd == SG_SCSI_RESET && ndelay) {
 		if (scsi_host_in_recovery(sdev->host))
 			return -ENODEV;
-	} else if (!scsi_block_when_processing_errors(sdev))
-		return -ENODEV;
-
-	switch (cmd) {
-	case SG_SCSI_RESET:
-		return scsi_ioctl_reset(sdev, arg);
+	} else {
+		if (!scsi_block_when_processing_errors(sdev))
+			return -ENODEV;
 	}
-	return -ENODEV;
+
+	return 0;
 }
-EXPORT_SYMBOL(scsi_nonblockable_ioctl);
+EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);