[SCSI] Fix printing of failed 32-byte commands

Having the large CDB allocation logic in sd.c means that
scsi_io_completion does not have access to the command buffer. That in
turn causes garbage to be printed when a 32-byte command fails. Move the
command printing to sd_done where the command buffer is intact.  Clear
the command buffer pointer after the extended CDB has been freed.

Make scsi_print_command ignore commands with NULL CDB pointers to
inhibit printing of garbled command strings.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 15 insertions, 1 deletions

diff --git a/drivers/scsi/constants.c b/drivers/scsi/constants.c
index 7092ff67ecd3..cd05e049d5f6 100644
--- a/drivers/scsi/constants.c
+++ b/drivers/scsi/constants.c
@@ -346,6 +346,9 @@ void scsi_print_command(struct scsi_cmnd *cmd)
 {
         int k;
 
+        if (cmd->cmnd == NULL)
+                return;
+
         scmd_printk(KERN_INFO, cmd, "CDB: ");
         print_opcode_name(cmd->cmnd, cmd->cmd_len);
 
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 908d400b601a..1dd4d8407694 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1209,8 +1209,19 @@ static int sd_done(struct scsi_cmnd *SCpnt)
                 sd_dif_complete(SCpnt, good_bytes);
 
         if (scsi_host_dif_capable(sdkp->device->host, sdkp->protection_type)
-            == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd)
+            == SD_DIF_TYPE2_PROTECTION && SCpnt->cmnd != SCpnt->request->cmd) {
+
+                /* We have to print a failed command here as the
+                 * extended CDB gets freed before scsi_io_completion()
+                 * is called.
+                 */
+                if (result)
+                        scsi_print_command(SCpnt);
+
                 mempool_free(SCpnt->cmnd, sd_cdb_pool);
+                SCpnt->cmnd = NULL;
+                SCpnt->cmd_len = 0;
+        }
 
         return good_bytes;
 }