scsi: core: Reshuffle response handling in scsi_mode_sense()

Reshuffle response handling in scsi_mode_sense() to make the code easier to
follow.

[mkp: fix build]

Link: https://lore.kernel.org/r/20210427083046.31620-5-hare@suse.de
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8614f61e385df5461649f78a1c400a9caef8ffe9..e763d368b892a1d5c3235cf15cf4d3f4bacfa20d 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2148,54 +2148,53 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
         * byte as the problem.  MODE_SENSE commands can return
         * ILLEGAL REQUEST if the code page isn't supported */
 
-       if (use_10_for_ms && !scsi_status_is_good(result) &&
-           driver_byte(result) == DRIVER_SENSE) {
-               if (scsi_sense_valid(sshdr)) {
+       if (!scsi_status_is_good(result)) {
+               if (driver_byte(result) == DRIVER_SENSE &&
+                   scsi_sense_valid(sshdr)) {
                        if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
                            (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
                                /*
                                 * Invalid command operation code
                                 */
-                               sdev->use_10_for_ms = 0;
+                               if (use_10_for_ms) {
+                                       sdev->use_10_for_ms = 0;
+                                       goto retry;
+                               }
+                       }
+                       if ((status_byte(result) == CHECK_CONDITION) &&
+                           sshdr->sense_key == UNIT_ATTENTION &&
+                           retry_count) {
+                               retry_count--;
                                goto retry;
                        }
                }
+               return -EIO;
+       }
+       if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
+                    (modepage == 6 || modepage == 8))) {
+               /* Initio breakage? */
+               header_length = 0;
+               data->length = 13;
+               data->medium_type = 0;
+               data->device_specific = 0;
+               data->longlba = 0;
+               data->block_descriptor_length = 0;
+       } else if (use_10_for_ms) {
+               data->length = buffer[0]*256 + buffer[1] + 2;
+               data->medium_type = buffer[2];
+               data->device_specific = buffer[3];
+               data->longlba = buffer[4] & 0x01;
+               data->block_descriptor_length = buffer[6]*256
+                       + buffer[7];
+       } else {
+               data->length = buffer[0] + 1;
+               data->medium_type = buffer[1];
+               data->device_specific = buffer[2];
+               data->block_descriptor_length = buffer[3];
        }
+       data->header_length = header_length;
 
-       if (scsi_status_is_good(result)) {
-               if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
-                            (modepage == 6 || modepage == 8))) {
-                       /* Initio breakage? */
-                       header_length = 0;
-                       data->length = 13;
-                       data->medium_type = 0;
-                       data->device_specific = 0;
-                       data->longlba = 0;
-                       data->block_descriptor_length = 0;
-               } else if (use_10_for_ms) {
-                       data->length = buffer[0]*256 + buffer[1] + 2;
-                       data->medium_type = buffer[2];
-                       data->device_specific = buffer[3];
-                       data->longlba = buffer[4] & 0x01;
-                       data->block_descriptor_length = buffer[6]*256
-                               + buffer[7];
-               } else {
-                       data->length = buffer[0] + 1;
-                       data->medium_type = buffer[1];
-                       data->device_specific = buffer[2];
-                       data->block_descriptor_length = buffer[3];
-               }
-               data->header_length = header_length;
-               result = 0;
-       } else if ((status_byte(result) == CHECK_CONDITION) &&
-                  scsi_sense_valid(sshdr) &&
-                  sshdr->sense_key == UNIT_ATTENTION && retry_count) {
-               retry_count--;
-               goto retry;
-       }
-       if (result > 0)
-               result = -EIO;
-       return result;
+       return 0;
 }
 EXPORT_SYMBOL(scsi_mode_sense);