dm: merge max_hw_sector
Make sure dm honours max_hw_sectors of underlying devices
We still have no firm testing evidence in support of this patch but
believe it may help to resolve some bug reports. - agk
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index f3f952e..47818d8 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -99,6 +99,9 @@
lhs->max_segment_size =
min_not_zero(lhs->max_segment_size, rhs->max_segment_size);
+ lhs->max_hw_sectors =
+ min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors);
+
lhs->seg_boundary_mask =
min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask);
@@ -566,6 +569,9 @@
rs->max_segment_size =
min_not_zero(rs->max_segment_size, q->max_segment_size);
+ rs->max_hw_sectors =
+ min_not_zero(rs->max_hw_sectors, q->max_hw_sectors);
+
rs->seg_boundary_mask =
min_not_zero(rs->seg_boundary_mask,
q->seg_boundary_mask);
@@ -703,6 +709,8 @@
{
if (!rs->max_sectors)
rs->max_sectors = SAFE_MAX_SECTORS;
+ if (!rs->max_hw_sectors)
+ rs->max_hw_sectors = SAFE_MAX_SECTORS;
if (!rs->max_phys_segments)
rs->max_phys_segments = MAX_PHYS_SEGMENTS;
if (!rs->max_hw_segments)
@@ -901,6 +909,7 @@
q->max_hw_segments = t->limits.max_hw_segments;
q->hardsect_size = t->limits.hardsect_size;
q->max_segment_size = t->limits.max_segment_size;
+ q->max_hw_sectors = t->limits.max_hw_sectors;
q->seg_boundary_mask = t->limits.seg_boundary_mask;
q->bounce_pfn = t->limits.bounce_pfn;
if (t->limits.no_cluster)
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index b8b7c51..e765e19 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -115,6 +115,7 @@
unsigned short max_hw_segments;
unsigned short hardsect_size;
unsigned int max_segment_size;
+ unsigned int max_hw_sectors;
unsigned long seg_boundary_mask;
unsigned long bounce_pfn;
unsigned char no_cluster; /* inverted so that 0 is default */