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);