Commit 8beb3300 authored by James Bottomley's avatar James Bottomley Committed by Martin K. Petersen

53c700: fix BUG on untagged commands

The untagged command case in the 53c700 driver has been broken since
host wide tags were enabled because the replaced scsi_find_tag()
function had a special case for the tag value SCSI_NO_TAG to retrieve
sdev->current_cmnd.  The replacement function scsi_host_find_tag() has
no such special case and returns NULL causing untagged commands to
trigger a BUG() in the driver.  Inspection shows that the 53c700 is the
only driver using this SCSI_NO_TAG case, so a local fix in the driver
suffices to fix this problem globally.

Fixes: 64d513ac - "scsi: use host wide tags by default"
Cc: stable@vger.kernel.org	# 4.4+
Reported-by: default avatarHelge Deller <deller@gmx.de>
Tested-by: default avatarHelge Deller <deller@gmx.de>
Signed-off-by: default avatarJames Bottomley <jejb@linux.vnet.ibm.com>
Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: default avatarEwan D. Milne <emilne@redhat.com>
Acked-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 72d8c36e
...@@ -1122,7 +1122,7 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp, ...@@ -1122,7 +1122,7 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
} else { } else {
struct scsi_cmnd *SCp; struct scsi_cmnd *SCp;
SCp = scsi_host_find_tag(SDp->host, SCSI_NO_TAG); SCp = SDp->current_cmnd;
if(unlikely(SCp == NULL)) { if(unlikely(SCp == NULL)) {
sdev_printk(KERN_ERR, SDp, sdev_printk(KERN_ERR, SDp,
"no saved request for untagged cmd\n"); "no saved request for untagged cmd\n");
...@@ -1826,7 +1826,7 @@ NCR_700_queuecommand_lck(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *) ...@@ -1826,7 +1826,7 @@ NCR_700_queuecommand_lck(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *)
slot->tag, slot); slot->tag, slot);
} else { } else {
slot->tag = SCSI_NO_TAG; slot->tag = SCSI_NO_TAG;
/* must populate current_cmnd for scsi_host_find_tag to work */ /* save current command for reselection */
SCp->device->current_cmnd = SCp; SCp->device->current_cmnd = SCp;
} }
/* sanity check: some of the commands generated by the mid-layer /* sanity check: some of the commands generated by the mid-layer
......
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