linux/drivers/nvdimm/label.h
Dan Williams 0ba1c63489 libnvdimm: write blk label set
After 'uuid', 'size', 'sector_size', and optionally 'alt_name' have been
set to valid values the labels on the dimm can be updated.  The
difference with the pmem case is that blk namespaces are limited to one
dimm and can cover discontiguous ranges in dpa space.

Also, after allocating label slots, it is useful for userspace to know
how many slots are left.  Export this information in sysfs.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-24 21:24:10 -04:00

142 lines
4.1 KiB
C

/*
* 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,
ND_NSINDEX_INIT = 0x1,
};
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);
int nd_label_active_count(struct nvdimm_drvdata *ndd);
struct nd_namespace_label *nd_label_active(struct nvdimm_drvdata *ndd, int n);
u32 nd_label_alloc_slot(struct nvdimm_drvdata *ndd);
bool nd_label_free_slot(struct nvdimm_drvdata *ndd, u32 slot);
u32 nd_label_nfree(struct nvdimm_drvdata *ndd);
struct nd_region;
struct nd_namespace_pmem;
struct nd_namespace_blk;
int nd_pmem_namespace_label_update(struct nd_region *nd_region,
struct nd_namespace_pmem *nspm, resource_size_t size);
int nd_blk_namespace_label_update(struct nd_region *nd_region,
struct nd_namespace_blk *nsblk, resource_size_t size);
#endif /* __LABEL_H__ */