diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2020-01-30 12:06:23 -0800 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2020-03-17 12:23:21 -0700 |
| commit | 2522afb86a8cceba0f67dbf05772d21b76d79f06 (patch) | |
| tree | 43ea32614b10933889836813b187d1e52eaf766d /drivers/nvdimm/namespace_devs.c | |
| parent | a0e374525def2ef18a078523e1faefb5ce2b05e5 (diff) | |
| download | linux-2522afb86a8cceba0f67dbf05772d21b76d79f06.tar.gz | |
libnvdimm/region: Introduce an 'align' attribute
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>
Diffstat (limited to 'drivers/nvdimm/namespace_devs.c')
| -rw-r--r-- | drivers/nvdimm/namespace_devs.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index 01f6c22f0d1a..ae155e860fdc 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -542,6 +542,11 @@ static void space_valid(struct nd_region *nd_region, struct nvdimm_drvdata *ndd, { bool is_reserve = strcmp(label_id->id, "pmem-reserve") == 0; bool is_pmem = strncmp(label_id->id, "pmem", 4) == 0; + unsigned long align; + + align = nd_region->align / nd_region->ndr_mappings; + valid->start = ALIGN(valid->start, align); + valid->end = ALIGN_DOWN(valid->end + 1, align) - 1; if (valid->start >= valid->end) goto invalid; @@ -981,10 +986,10 @@ static ssize_t __size_store(struct device *dev, unsigned long long val) return -ENXIO; } - div_u64_rem(val, PAGE_SIZE * nd_region->ndr_mappings, &remainder); + div_u64_rem(val, nd_region->align, &remainder); if (remainder) { dev_dbg(dev, "%llu is not %ldK aligned\n", val, - (PAGE_SIZE * nd_region->ndr_mappings) / SZ_1K); + nd_region->align / SZ_1K); return -EINVAL; } |