[SCSI] scsi_debug: fix logical block provisioning support when unmap_alignment != 0
authorAkinobu Mita <akinobu.mita@gmail.com>
Mon, 26 Aug 2013 13:08:41 +0000 (22:08 +0900)
committerJames Bottomley <JBottomley@Parallels.com>
Tue, 3 Sep 2013 14:28:08 +0000 (07:28 -0700)
commita027b5b90eb6b5ec5c5890a5e4e198f458ae94cb
treed8406f527912266c7568a8d6f7e9eb64f92e14c9
parent150c3544b1d317fe32b1f279917c08638dad363f
[SCSI] scsi_debug: fix logical block provisioning support when unmap_alignment != 0

Commit b90ebc3d5c41c9164ae04efd2e4f8204c2a186f1 ("[SCSI] scsi_debug:
fix logical block provisioning support") fixed several issues with
logical block provisioning support, but it still doesn't properly fix
the cases when unmap_alignment > 0.

For example, load scsi_debug module with the following module parameters
and make all blocks mapped by filling the storage with zero.

        # modprobe scsi_debug lbpu=1 unmap_alignment=1 unmap_granularity=4
        # dd if=/dev/zero of=$DEV

Then, try to unmap the first unmappable blocks at lba=1, but GET LBA STATUS
unexpectedly reports that the last UNMAP has done nothing.

        # sg_unmap --lba=1 --num=4 $DEV
        # sg_get_lba_status --lba=1 $DEV
        descriptor LBA: 0x0000000000000001  blocks: 16383  mapped

The problem is in map_index_to_lba(), which should return the first
LBA which is corresponding to a given index of provisioning map
(map_storep).

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
drivers/scsi/scsi_debug.c