This is a note to let you know that I've just added the patch titled
nvdimm/region: Fix default alignment for small regions
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nvdimm-region-fix-default-alignment-for-small-region.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e881748f0a7449f715a42831dfe61009f6f3ff4d
Author: Dan Williams <dan.j.williams@xxxxxxxxx>
Date: Wed Mar 9 19:49:21 2022 -0800
nvdimm/region: Fix default alignment for small regions
[ Upstream commit d9d290d7e659e9db3e4518040cc18b97f5535f4a ]
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 <hch@xxxxxx>
Link: https://lore.kernel.org/r/164688416128.2879318.17890707310125575258.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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)
