linux-kernel - [PATCH 4/7] libnvdimm, dax: record the specified alignment of a dax-device instance

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 08 May 2016 15:35:31 -0700
From:	Dan Williams <dan.j.williams@...el.com>
To:	linux-nvdimm@...ts.01.org
Cc:	linux-block@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 4/7] libnvdimm,
 dax: record the specified alignment of a dax-device instance

We want to use the alignment as the allocation and mapping unit.
Previously this information was only useful for establishing the data
offset, but now it is important to remember the granularity for the
later use.

Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
 drivers/nvdimm/pfn.h      |    4 +++-
 drivers/nvdimm/pfn_devs.c |    8 ++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 8e343a3ca873..9d2704c83fa7 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -33,7 +33,9 @@ struct nd_pfn_sb {
 	/* minor-version-1 additions for section alignment */
 	__le32 start_pad;
 	__le32 end_trunc;
-	u8 padding[4004];
+	/* minor-version-2 record the base alignment of the mapping */
+	__le32 align;
+	u8 padding[4000];
 	__le64 checksum;
 };
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index ca396c8f2cd5..58740d7ce81b 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -394,6 +394,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		pfn_sb->end_trunc = 0;
 	}
 
+	if (__le16_to_cpu(pfn_sb->version_minor) < 2)
+		pfn_sb->align = 0;
+
 	switch (le32_to_cpu(pfn_sb->mode)) {
 	case PFN_MODE_RAM:
 	case PFN_MODE_PMEM:
@@ -433,7 +436,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 		return -EBUSY;
 	}
 
-	nd_pfn->align = 1UL << ilog2(offset);
+	nd_pfn->align = le32_to_cpu(pfn_sb->align);
 	if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
 		dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
 				offset);
@@ -629,9 +632,10 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 	memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 	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(1);
+	pfn_sb->version_minor = cpu_to_le16(2);
 	pfn_sb->start_pad = cpu_to_le32(start_pad);
 	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);