scsi: retry MODE SENSE on unit attention
authorHannes Reinecke <hare@suse.de>
Fri, 12 Jun 2015 14:12:48 +0000 (16:12 +0200)
committerJames Bottomley <JBottomley@Odin.com>
Thu, 30 Jul 2015 19:37:20 +0000 (12:37 -0700)
The 'sd' driver is calling scsi_mode_sense() to figure out
internal details. But scsi_mode_sense() never checks for
any pending unit attentions, so we're getting annoying error
messages like:

MODE SENSE: unimplemented page/subpage: 0x00/0x00

and a possible wrong decision for device cache handling.

Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
drivers/scsi/scsi_lib.c

index 448ebdaa3d694758dd899b1c06ce379d0676898a..dffa91c67f5b9f5ca8a8e848481cf78174958745 100644 (file)
@@ -2423,7 +2423,7 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
        unsigned char cmd[12];
        int use_10_for_ms;
        int header_length;
-       int result;
+       int result, retry_count = retries;
        struct scsi_sense_hdr my_sshdr;
 
        memset(data, 0, sizeof(*data));
@@ -2502,6 +2502,11 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
                        data->block_descriptor_length = buffer[3];
                }
                data->header_length = header_length;
+       } else if ((status_byte(result) == CHECK_CONDITION) &&
+                  scsi_sense_valid(sshdr) &&
+                  sshdr->sense_key == UNIT_ATTENTION && retry_count) {
+               retry_count--;
+               goto retry;
        }
 
        return result;