From: Neil Brown 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 Signed-off-by: Alasdair G Kergon --- drivers/md/dm-table.c | 9 +++++++++ include/linux/device-mapper.h | 1 + 2 files changed, 10 insertions(+) Index: linux-2.6.24-rc5/drivers/md/dm-table.c =================================================================== --- linux-2.6.24-rc5.orig/drivers/md/dm-table.c 2007-12-12 15:43:06.000000000 +0000 +++ linux-2.6.24-rc5/drivers/md/dm-table.c 2007-12-13 13:25:45.000000000 +0000 @@ -99,6 +99,9 @@ static void combine_restrictions_low(str 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 @@ void dm_set_device_limits(struct dm_targ 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 @@ static void check_for_valid_limits(struc { 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 @@ void dm_table_set_restrictions(struct dm 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) Index: linux-2.6.24-rc5/include/linux/device-mapper.h =================================================================== --- linux-2.6.24-rc5.orig/include/linux/device-mapper.h 2007-12-12 15:40:33.000000000 +0000 +++ linux-2.6.24-rc5/include/linux/device-mapper.h 2007-12-13 13:25:44.000000000 +0000 @@ -115,6 +115,7 @@ struct io_restrictions { 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 */