From d9d290d7e659e9db3e4518040cc18b97f5535f4a Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 9 Mar 2022 19:49:21 -0800 Subject: nvdimm/region: Fix default alignment for small regions In preparation for removing BLK aperture support the NVDIMM unit tests discovered that the default alignment can be set higher than the capacity of the region. Fall back to PAGE_SIZE in that case. Given this has not been seen in the wild, elide notifying -stable. Fixes: 2522afb86a8c ("libnvdimm/region: Introduce an 'align' attribute") Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/164688416128.2879318.17890707310125575258.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams --- drivers/nvdimm/region_devs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index 9ccf3d608799..70ad891a76ba 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -1025,6 +1025,9 @@ static unsigned long default_align(struct nd_region *nd_region) } } + if (nd_region->ndr_size < MEMREMAP_COMPAT_ALIGN_MAX) + align = PAGE_SIZE; + mappings = max_t(u16, 1, nd_region->ndr_mappings); div_u64_rem(align, mappings, &remainder); if (remainder) -- cgit v1.2.3