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authorDan Williams <dan.j.williams@intel.com>2015-06-09 16:09:36 -0400
committerDan Williams <dan.j.williams@intel.com>2015-06-24 21:24:10 -0400
commit4a826c83db4edc040da3a66dbefd53f0cfcf457d (patch)
treeff26d9df31e46d3f7d8ff12fa288982460beacc3 /drivers/nvdimm/label.h
parenteaf961536e1622ad21247ac8d44acd48ba65566e (diff)
libnvdimm: namespace indices: read and validate
This on media label format [1] consists of two index blocks followed by an array of labels. None of these structures are ever updated in place. A sequence number tracks the current active index and the next one to write, while labels are written to free slots. +------------+ | | | nsindex0 | | | +------------+ | | | nsindex1 | | | +------------+ | label0 | +------------+ | label1 | +------------+ | | ....nslot... | | +------------+ | labelN | +------------+ After reading valid labels, store the dpa ranges they claim into per-dimm resource trees. [1]: http://pmem.io/documents/NVDIMM_Namespace_Spec.pdf Cc: Neil Brown <neilb@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/label.h')
-rw-r--r--drivers/nvdimm/label.h128
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/nvdimm/label.h b/drivers/nvdimm/label.h
new file mode 100644
index 000000000000..d6aa0d5c6b4e
--- /dev/null
+++ b/drivers/nvdimm/label.h
@@ -0,0 +1,128 @@
+/*
+ * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#ifndef __LABEL_H__
+#define __LABEL_H__
+
+#include <linux/ndctl.h>
+#include <linux/sizes.h>
+#include <linux/io.h>
+
+enum {
+ NSINDEX_SIG_LEN = 16,
+ NSINDEX_ALIGN = 256,
+ NSINDEX_SEQ_MASK = 0x3,
+ NSLABEL_UUID_LEN = 16,
+ NSLABEL_NAME_LEN = 64,
+ NSLABEL_FLAG_ROLABEL = 0x1, /* read-only label */
+ NSLABEL_FLAG_LOCAL = 0x2, /* DIMM-local namespace */
+ NSLABEL_FLAG_BTT = 0x4, /* namespace contains a BTT */
+ NSLABEL_FLAG_UPDATING = 0x8, /* label being updated */
+ BTT_ALIGN = 4096, /* all btt structures */
+ BTTINFO_SIG_LEN = 16,
+ BTTINFO_UUID_LEN = 16,
+ BTTINFO_FLAG_ERROR = 0x1, /* error state (read-only) */
+ BTTINFO_MAJOR_VERSION = 1,
+ ND_LABEL_MIN_SIZE = 512 * 129, /* see sizeof_namespace_index() */
+ ND_LABEL_ID_SIZE = 50,
+};
+
+static const char NSINDEX_SIGNATURE[] = "NAMESPACE_INDEX\0";
+
+/**
+ * struct nd_namespace_index - label set superblock
+ * @sig: NAMESPACE_INDEX\0
+ * @flags: placeholder
+ * @seq: sequence number for this index
+ * @myoff: offset of this index in label area
+ * @mysize: size of this index struct
+ * @otheroff: offset of other index
+ * @labeloff: offset of first label slot
+ * @nslot: total number of label slots
+ * @major: label area major version
+ * @minor: label area minor version
+ * @checksum: fletcher64 of all fields
+ * @free[0]: bitmap, nlabel bits
+ *
+ * The size of free[] is rounded up so the total struct size is a
+ * multiple of NSINDEX_ALIGN bytes. Any bits this allocates beyond
+ * nlabel bits must be zero.
+ */
+struct nd_namespace_index {
+ u8 sig[NSINDEX_SIG_LEN];
+ __le32 flags;
+ __le32 seq;
+ __le64 myoff;
+ __le64 mysize;
+ __le64 otheroff;
+ __le64 labeloff;
+ __le32 nslot;
+ __le16 major;
+ __le16 minor;
+ __le64 checksum;
+ u8 free[0];
+};
+
+/**
+ * struct nd_namespace_label - namespace superblock
+ * @uuid: UUID per RFC 4122
+ * @name: optional name (NULL-terminated)
+ * @flags: see NSLABEL_FLAG_*
+ * @nlabel: num labels to describe this ns
+ * @position: labels position in set
+ * @isetcookie: interleave set cookie
+ * @lbasize: LBA size in bytes or 0 for pmem
+ * @dpa: DPA of NVM range on this DIMM
+ * @rawsize: size of namespace
+ * @slot: slot of this label in label area
+ * @unused: must be zero
+ */
+struct nd_namespace_label {
+ u8 uuid[NSLABEL_UUID_LEN];
+ u8 name[NSLABEL_NAME_LEN];
+ __le32 flags;
+ __le16 nlabel;
+ __le16 position;
+ __le64 isetcookie;
+ __le64 lbasize;
+ __le64 dpa;
+ __le64 rawsize;
+ __le32 slot;
+ __le32 unused;
+};
+
+/**
+ * struct nd_label_id - identifier string for dpa allocation
+ * @id: "{blk|pmem}-<namespace uuid>"
+ */
+struct nd_label_id {
+ char id[ND_LABEL_ID_SIZE];
+};
+
+/*
+ * If the 'best' index is invalid, so is the 'next' index. Otherwise,
+ * the next index is MOD(index+1, 2)
+ */
+static inline int nd_label_next_nsindex(int index)
+{
+ if (index < 0)
+ return -1;
+
+ return (index + 1) % 2;
+}
+
+struct nvdimm_drvdata;
+int nd_label_validate(struct nvdimm_drvdata *ndd);
+void nd_label_copy(struct nvdimm_drvdata *ndd, struct nd_namespace_index *dst,
+ struct nd_namespace_index *src);
+size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd);
+#endif /* __LABEL_H__ */

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