scsi_scan: Restrict sequential scan to 256 LUNs

Sequential scan for more than 256 LUNs is very fragile as
LUNs might not be numbered sequentially after that point.

SAM revisions later than SCSI-3 impose a structure on
LUNs larger than 256, making LUN numbers between 256
and 16384 illegal.
SCSI-3, however allows for plain 64-bit numbers with
no internal structure.

So restrict sequential LUN scan to 256 LUNs and add a
new blacklist flag 'BLIST_SCSI3LUN' to scan up to
max_lun devices.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Hannes Reinecke
2014-06-03 10:58:53 +02:00
committed by Christoph Hellwig
parent c309b35171
commit 22ffeb48b7
2 changed files with 8 additions and 0 deletions

View File

@@ -1234,6 +1234,12 @@ static void scsi_sequential_lun_scan(struct scsi_target *starget,
if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
max_dev_lun = min(8U, max_dev_lun);
/*
* Stop scanning at 255 unless BLIST_SCSI3LUN
*/
if (!(bflags & BLIST_SCSI3LUN))
max_dev_lun = min(256U, max_dev_lun);
/*
* We have already scanned LUN 0, so start at LUN 1. Keep scanning
* until we reach the max, or no LUN is found and we are not