From 274b924088e93593c76fb122d24bc0ef18d0ddf4 Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Wed, 28 Aug 2019 11:49:46 -0400 Subject: [PATCH] libnvdimm/pfn: Fix namespace creation on misaligned addresses Yi reported[1] that after commit a3619190d62e ("libnvdimm/pfn: stop padding pmem namespaces to section alignment"), it was no longer possible to create a device dax namespace with a 1G alignment. The reason was that the pmem region was not itself 1G-aligned. The code happily skips past the first 512M, but fails to account for a now misaligned end offset (since space was allocated starting at that misaligned address, and extending for size GBs). Reintroduce end_trunc, so that the code correctly handles the misaligned end address. This results in the same behavior as before the introduction of the offending commit. [1] https://lists.01.org/pipermail/linux-nvdimm/2019-July/022813.html Fixes: a3619190d62e ("libnvdimm/pfn: stop padding pmem namespaces ...") Reported-and-tested-by: Yi Zhang Signed-off-by: Jeff Moyer Link: https://lore.kernel.org/r/x49ftll8f39.fsf@segfault.boston.devel.redhat.com Signed-off-by: Dan Williams --- drivers/nvdimm/pfn_devs.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 3e7b11c..cb98b8f 100644 --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -655,6 +655,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) resource_size_t start, size; struct nd_region *nd_region; unsigned long npfns, align; + u32 end_trunc; struct nd_pfn_sb *pfn_sb; phys_addr_t offset; const char *sig; @@ -696,6 +697,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) size = resource_size(&nsio->res); npfns = PHYS_PFN(size - SZ_8K); align = max(nd_pfn->align, (1UL << SUBSECTION_SHIFT)); + end_trunc = start + size - ALIGN_DOWN(start + size, align); if (nd_pfn->mode == PFN_MODE_PMEM) { /* * The altmap should be padded out to the block size used @@ -714,7 +716,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) return -ENXIO; } - npfns = PHYS_PFN(size - offset); + npfns = PHYS_PFN(size - offset - end_trunc); pfn_sb->mode = cpu_to_le32(nd_pfn->mode); pfn_sb->dataoff = cpu_to_le64(offset); pfn_sb->npfns = cpu_to_le64(npfns); @@ -723,6 +725,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16); pfn_sb->version_major = cpu_to_le16(1); pfn_sb->version_minor = cpu_to_le16(3); + pfn_sb->end_trunc = cpu_to_le32(end_trunc); pfn_sb->align = cpu_to_le32(nd_pfn->align); checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb); pfn_sb->checksum = cpu_to_le64(checksum); -- 2.7.4