[PATCH 0/2] scsi_debug: bug fixes for certain module parameters

[PATCH 0/2] scsi_debug: bug fixes for certain module parameters

[Akinobu Mita]

Hi James,

Please consider to apply these patches to your tree.  These patches are
subset of the patch set I sent before:
http://marc.info/?l=linux-scsi&m=137388918402750&w=2
I'm sending the patches which have been acked by the appropriate reviewers.
The rest of the patches need some rework, and I'll try to submit next time.

Akinobu Mita (2):
  scsi_debug: fix endianness bug in sdebug_build_parts()
  scsi_debug: fix logical block provisioning support when
    unmap_alignment != 0

 drivers/scsi/scsi_debug.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
-- 
1.8.3.1

[PATCH 1/2] scsi_debug: fix endianness bug in sdebug_build_parts()

[Akinobu Mita]

With module parameter num_parts > 0, partition table is built on the
ramdisk storage when loading the driver.  Unfortunately, there is an
endianness bug in sdebug_build_parts().  So the partition table is not
correctly initialized on big-endian systems.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: linux-scsi@vger.kernel.org
---
 drivers/scsi/scsi_debug.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index cb4fefa..2f39b13 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -2659,8 +2659,8 @@ static void __init sdebug_build_parts(unsigned char *ramp,
 			       / sdebug_sectors_per;
 		pp->end_sector = (end_sec % sdebug_sectors_per) + 1;
 
-		pp->start_sect = start_sec;
-		pp->nr_sects = end_sec - start_sec + 1;
+		pp->start_sect = cpu_to_le32(start_sec);
+		pp->nr_sects = cpu_to_le32(end_sec - start_sec + 1);
 		pp->sys_ind = 0x83;	/* plain Linux partition */
 	}
 }
-- 
1.8.3.1

[PATCH 2/2] scsi_debug: fix logical block provisioning support when unmap_alignment != 0

[Akinobu Mita]

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: Douglas Gilbert <dgilbert@interlog.com>
Acked-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
---
 drivers/scsi/scsi_debug.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 2f39b13..01c0ffa 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1997,8 +1997,14 @@ static unsigned long lba_to_map_index(sector_t lba)
 
 static sector_t map_index_to_lba(unsigned long index)
 {
-	return index * scsi_debug_unmap_granularity -
-		scsi_debug_unmap_alignment;
+	sector_t lba = index * scsi_debug_unmap_granularity;
+
+	if (scsi_debug_unmap_alignment) {
+		lba -= scsi_debug_unmap_granularity -
+			scsi_debug_unmap_alignment;
+	}
+
+	return lba;
 }
 
 static unsigned int map_state(sector_t lba, unsigned int *num)
-- 
1.8.3.1