diff options
author | Dan Williams <dan.j.williams@intel.com> | 2015-06-09 23:09:36 +0300 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2015-06-25 04:24:10 +0300 |
commit | 4a826c83db4edc040da3a66dbefd53f0cfcf457d (patch) | |
tree | ff26d9df31e46d3f7d8ff12fa288982460beacc3 /drivers/nvdimm/label.h | |
parent | eaf961536e1622ad21247ac8d44acd48ba65566e (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.h | 128 |
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__ */ |