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2522afb86a
The align attribute applies an alignment constraint for namespace creation in a region. Whereas the 'align' attribute of a namespace applied alignment padding via an info block, the 'align' attribute applies alignment constraints to the free space allocation. The default for 'align' is the maximum known memremap_compat_align() across all archs (16MiB from PowerPC at time of writing) multiplied by the number of interleave ways if there is blk-aliasing. The minimum is PAGE_SIZE and allows for the creation of cross-arch incompatible namespaces, just as previous kernels allowed, but the expectation is cross-arch and mode-independent compatibility by default. The regression risk with this change is limited to cases that were dependent on the ability to create unaligned namespaces, *and* for some reason are unable to opt-out of aligned namespaces by writing to 'regionX/align'. If such a scenario arises the default can be flipped from opt-out to opt-in of compat-aligned namespace creation, but that is a last resort. The kernel will otherwise continue to support existing defined misaligned namespaces. Unfortunately this change needs to touch several parts of the implementation at once: - region/available_size: expand busy extents to current align - region/max_available_extent: expand busy extents to current align - namespace/size: trim free space to current align ...to keep the free space accounting conforming to the dynamic align setting. Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reported-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Link: https://lore.kernel.org/r/158041478371.3889308.14542630147672668068.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> |
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| .. | ||
| badrange.c | ||
| blk.c | ||
| btt.c | ||
| btt.h | ||
| btt_devs.c | ||
| bus.c | ||
| claim.c | ||
| core.c | ||
| dax_devs.c | ||
| dimm.c | ||
| dimm_devs.c | ||
| e820.c | ||
| Kconfig | ||
| label.c | ||
| label.h | ||
| Makefile | ||
| namespace_devs.c | ||
| nd-core.h | ||
| nd.h | ||
| nd_virtio.c | ||
| of_pmem.c | ||
| pfn.h | ||
| pfn_devs.c | ||
| pmem.c | ||
| pmem.h | ||
| region.c | ||
| region_devs.c | ||
| security.c | ||
| virtio_pmem.c | ||
| virtio_pmem.h | ||