The C and C++ Include Header Files

/usr/include/linux/raid/md_p.h


$ cat -n /usr/include/linux/raid/md_p.h

     1	/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
     2	/*
     3	   md_p.h : physical layout of Linux RAID devices
     4	          Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
     5	
     6	   This program is free software; you can redistribute it and/or modify
     7	   it under the terms of the GNU General Public License as published by
     8	   the Free Software Foundation; either version 2, or (at your option)
     9	   any later version.
    10	*/
    11	
    12	#ifndef _MD_P_H
    13	#define _MD_P_H
    14	
    15	#include <linux/types.h>
    16	#include <asm/byteorder.h>
    17	
    18	/*
    19	 * RAID superblock.
    20	 *
    21	 * The RAID superblock maintains some statistics on each RAID configuration.
    22	 * Each real device in the RAID set contains it near the end of the device.
    23	 * Some of the ideas are copied from the ext2fs implementation.
    24	 *
    25	 * We currently use 4096 bytes as follows:
    26	 *
    27	 *	word offset	function
    28	 *
    29	 *	   0  -    31	Constant generic RAID device information.
    30	 *        32  -    63   Generic state information.
    31	 *	  64  -   127	Personality specific information.
    32	 *	 128  -   511	12 32-words descriptors of the disks in the raid set.
    33	 *	 512  -   911	Reserved.
    34	 *	 912  -  1023	Disk specific descriptor.
    35	 */
    36	
    37	/*
    38	 * If x is the real device size in bytes, we return an apparent size of:
    39	 *
    40	 *	y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES
    41	 *
    42	 * and place the 4kB superblock at offset y.
    43	 */
    44	#define MD_RESERVED_BYTES		(64 * 1024)
    45	#define MD_RESERVED_SECTORS		(MD_RESERVED_BYTES / 512)
    46	
    47	#define MD_NEW_SIZE_SECTORS(x)		((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS)
    48	
    49	#define MD_SB_BYTES			4096
    50	#define MD_SB_WORDS			(MD_SB_BYTES / 4)
    51	#define MD_SB_SECTORS			(MD_SB_BYTES / 512)
    52	
    53	/*
    54	 * The following are counted in 32-bit words
    55	 */
    56	#define	MD_SB_GENERIC_OFFSET		0
    57	#define MD_SB_PERSONALITY_OFFSET	64
    58	#define MD_SB_DISKS_OFFSET		128
    59	#define MD_SB_DESCRIPTOR_OFFSET		992
    60	
    61	#define MD_SB_GENERIC_CONSTANT_WORDS	32
    62	#define MD_SB_GENERIC_STATE_WORDS	32
    63	#define MD_SB_GENERIC_WORDS		(MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS)
    64	#define MD_SB_PERSONALITY_WORDS		64
    65	#define MD_SB_DESCRIPTOR_WORDS		32
    66	#define MD_SB_DISKS			27
    67	#define MD_SB_DISKS_WORDS		(MD_SB_DISKS*MD_SB_DESCRIPTOR_WORDS)
    68	#define MD_SB_RESERVED_WORDS		(1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS)
    69	#define MD_SB_EQUAL_WORDS		(MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS)
    70	
    71	/*
    72	 * Device "operational" state bits
    73	 */
    74	#define MD_DISK_FAULTY		0 /* disk is faulty / operational */
    75	#define MD_DISK_ACTIVE		1 /* disk is running or spare disk */
    76	#define MD_DISK_SYNC		2 /* disk is in sync with the raid set */
    77	#define MD_DISK_REMOVED		3 /* disk is in sync with the raid set */
    78	#define MD_DISK_CLUSTER_ADD     4 /* Initiate a disk add across the cluster
    79					   * For clustered enviroments only.
    80					   */
    81	#define MD_DISK_CANDIDATE	5 /* disk is added as spare (local) until confirmed
    82					   * For clustered enviroments only.
    83					   */
    84	#define MD_DISK_FAILFAST	10 /* Send REQ_FAILFAST if there are multiple
    85					    * devices available - and don't try to
    86					    * correct read errors.
    87					    */
    88	
    89	#define	MD_DISK_WRITEMOSTLY	9 /* disk is "write-mostly" is RAID1 config.
    90					   * read requests will only be sent here in
    91					   * dire need
    92					   */
    93	#define MD_DISK_JOURNAL		18 /* disk is used as the write journal in RAID-5/6 */
    94	
    95	#define MD_DISK_ROLE_SPARE	0xffff
    96	#define MD_DISK_ROLE_FAULTY	0xfffe
    97	#define MD_DISK_ROLE_JOURNAL	0xfffd
    98	#define MD_DISK_ROLE_MAX	0xff00 /* max value of regular disk role */
    99	
   100	typedef struct mdp_device_descriptor_s {
   101		__u32 number;		/* 0 Device number in the entire set	      */
   102		__u32 major;		/* 1 Device major number		      */
   103		__u32 minor;		/* 2 Device minor number		      */
   104		__u32 raid_disk;	/* 3 The role of the device in the raid set   */
   105		__u32 state;		/* 4 Operational state			      */
   106		__u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5];
   107	} mdp_disk_t;
   108	
   109	#define MD_SB_MAGIC		0xa92b4efc
   110	
   111	/*
   112	 * Superblock state bits
   113	 */
   114	#define MD_SB_CLEAN		0
   115	#define MD_SB_ERRORS		1
   116	
   117	#define	MD_SB_CLUSTERED		5 /* MD is clustered */
   118	#define	MD_SB_BITMAP_PRESENT	8 /* bitmap may be present nearby */
   119	
   120	/*
   121	 * Notes:
   122	 * - if an array is being reshaped (restriped) in order to change
   123	 *   the number of active devices in the array, 'raid_disks' will be
   124	 *   the larger of the old and new numbers.  'delta_disks' will
   125	 *   be the "new - old".  So if +ve, raid_disks is the new value, and
   126	 *   "raid_disks-delta_disks" is the old.  If -ve, raid_disks is the
   127	 *   old value and "raid_disks+delta_disks" is the new (smaller) value.
   128	 */
   129	
   130	
   131	typedef struct mdp_superblock_s {
   132		/*
   133		 * Constant generic information
   134		 */
   135		__u32 md_magic;		/*  0 MD identifier 			      */
   136		__u32 major_version;	/*  1 major version to which the set conforms */
   137		__u32 minor_version;	/*  2 minor version ...			      */
   138		__u32 patch_version;	/*  3 patchlevel version ...		      */
   139		__u32 gvalid_words;	/*  4 Number of used words in this section    */
   140		__u32 set_uuid0;	/*  5 Raid set identifier		      */
   141		__u32 ctime;		/*  6 Creation time			      */
   142		__u32 level;		/*  7 Raid personality			      */
   143		__u32 size;		/*  8 Apparent size of each individual disk   */
   144		__u32 nr_disks;		/*  9 total disks in the raid set	      */
   145		__u32 raid_disks;	/* 10 disks in a fully functional raid set    */
   146		__u32 md_minor;		/* 11 preferred MD minor device number	      */
   147		__u32 not_persistent;	/* 12 does it have a persistent superblock    */
   148		__u32 set_uuid1;	/* 13 Raid set identifier #2		      */
   149		__u32 set_uuid2;	/* 14 Raid set identifier #3		      */
   150		__u32 set_uuid3;	/* 15 Raid set identifier #4		      */
   151		__u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 16];
   152	
   153		/*
   154		 * Generic state information
   155		 */
   156		__u32 utime;		/*  0 Superblock update time		      */
   157		__u32 state;		/*  1 State bits (clean, ...)		      */
   158		__u32 active_disks;	/*  2 Number of currently active disks	      */
   159		__u32 working_disks;	/*  3 Number of working disks		      */
   160		__u32 failed_disks;	/*  4 Number of failed disks		      */
   161		__u32 spare_disks;	/*  5 Number of spare disks		      */
   162		__u32 sb_csum;		/*  6 checksum of the whole superblock        */
   163	#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
   164		__u32 events_hi;	/*  7 high-order of superblock update count   */
   165		__u32 events_lo;	/*  8 low-order of superblock update count    */
   166		__u32 cp_events_hi;	/*  9 high-order of checkpoint update count   */
   167		__u32 cp_events_lo;	/* 10 low-order of checkpoint update count    */
   168	#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
   169		__u32 events_lo;	/*  7 low-order of superblock update count    */
   170		__u32 events_hi;	/*  8 high-order of superblock update count   */
   171		__u32 cp_events_lo;	/*  9 low-order of checkpoint update count    */
   172		__u32 cp_events_hi;	/* 10 high-order of checkpoint update count   */
   173	#else
   174	#error unspecified endianness
   175	#endif
   176		__u32 recovery_cp;	/* 11 recovery checkpoint sector count	      */
   177		/* There are only valid for minor_version > 90 */
   178		__u64 reshape_position;	/* 12,13 next address in array-space for reshape */
   179		__u32 new_level;	/* 14 new level we are reshaping to	      */
   180		__u32 delta_disks;	/* 15 change in number of raid_disks	      */
   181		__u32 new_layout;	/* 16 new layout			      */
   182		__u32 new_chunk;	/* 17 new chunk size (bytes)		      */
   183		__u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 18];
   184	
   185		/*
   186		 * Personality information
   187		 */
   188		__u32 layout;		/*  0 the array's physical layout	      */
   189		__u32 chunk_size;	/*  1 chunk size in bytes		      */
   190		__u32 root_pv;		/*  2 LV root PV */
   191		__u32 root_block;	/*  3 LV root block */
   192		__u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 4];
   193	
   194		/*
   195		 * Disks information
   196		 */
   197		mdp_disk_t disks[MD_SB_DISKS];
   198	
   199		/*
   200		 * Reserved
   201		 */
   202		__u32 reserved[MD_SB_RESERVED_WORDS];
   203	
   204		/*
   205		 * Active descriptor
   206		 */
   207		mdp_disk_t this_disk;
   208	
   209	} mdp_super_t;
   210	
   211	static __inline__ __u64 md_event(mdp_super_t *sb) {
   212		__u64 ev = sb->events_hi;
   213		return (ev<<32)| sb->events_lo;
   214	}
   215	
   216	#define MD_SUPERBLOCK_1_TIME_SEC_MASK ((1ULL<<40) - 1)
   217	
   218	/*
   219	 * The version-1 superblock :
   220	 * All numeric fields are little-endian.
   221	 *
   222	 * total size: 256 bytes plus 2 per device.
   223	 *  1K allows 384 devices.
   224	 */
   225	struct mdp_superblock_1 {
   226		/* constant array information - 128 bytes */
   227		__le32	magic;		/* MD_SB_MAGIC: 0xa92b4efc - little endian */
   228		__le32	major_version;	/* 1 */
   229		__le32	feature_map;	/* bit 0 set if 'bitmap_offset' is meaningful */
   230		__le32	pad0;		/* always set to 0 when writing */
   231	
   232		__u8	set_uuid[16];	/* user-space generated. */
   233		char	set_name[32];	/* set and interpreted by user-space */
   234	
   235		__le64	ctime;		/* lo 40 bits are seconds, top 24 are microseconds or 0*/
   236		__le32	level;		/* 0,1,4,5 */
   237		__le32	layout;		/* only for raid5 and raid10 currently */
   238		__le64	size;		/* used size of component devices, in 512byte sectors */
   239	
   240		__le32	chunksize;	/* in 512byte sectors */
   241		__le32	raid_disks;
   242		union {
   243			__le32	bitmap_offset;	/* sectors after start of superblock that bitmap starts
   244						 * NOTE: signed, so bitmap can be before superblock
   245						 * only meaningful of feature_map[0] is set.
   246						 */
   247	
   248			/* only meaningful when feature_map[MD_FEATURE_PPL] is set */
   249			struct {
   250				__le16 offset; /* sectors from start of superblock that ppl starts (signed) */
   251				__le16 size; /* ppl size in sectors */
   252			} ppl;
   253		};
   254	
   255		/* These are only valid with feature bit '4' */
   256		__le32	new_level;	/* new level we are reshaping to		*/
   257		__le64	reshape_position;	/* next address in array-space for reshape */
   258		__le32	delta_disks;	/* change in number of raid_disks		*/
   259		__le32	new_layout;	/* new layout					*/
   260		__le32	new_chunk;	/* new chunk size (512byte sectors)		*/
   261		__le32  new_offset;	/* signed number to add to data_offset in new
   262					 * layout.  0 == no-change.  This can be
   263					 * different on each device in the array.
   264					 */
   265	
   266		/* constant this-device information - 64 bytes */
   267		__le64	data_offset;	/* sector start of data, often 0 */
   268		__le64	data_size;	/* sectors in this device that can be used for data */
   269		__le64	super_offset;	/* sector start of this superblock */
   270		union {
   271			__le64	recovery_offset;/* sectors before this offset (from data_offset) have been recovered */
   272			__le64	journal_tail;/* journal tail of journal device (from data_offset) */
   273		};
   274		__le32	dev_number;	/* permanent identifier of this  device - not role in raid */
   275		__le32	cnt_corrected_read; /* number of read errors that were corrected by re-writing */
   276		__u8	device_uuid[16]; /* user-space setable, ignored by kernel */
   277		__u8	devflags;	/* per-device flags.  Only two defined...*/
   278	#define	WriteMostly1	1	/* mask for writemostly flag in above */
   279	#define	FailFast1	2	/* Should avoid retries and fixups and just fail */
   280		/* Bad block log.  If there are any bad blocks the feature flag is set.
   281		 * If offset and size are non-zero, that space is reserved and available
   282		 */
   283		__u8	bblog_shift;	/* shift from sectors to block size */
   284		__le16	bblog_size;	/* number of sectors reserved for list */
   285		__le32	bblog_offset;	/* sector offset from superblock to bblog,
   286					 * signed - not unsigned */
   287	
   288		/* array state information - 64 bytes */
   289		__le64	utime;		/* 40 bits second, 24 bits microseconds */
   290		__le64	events;		/* incremented when superblock updated */
   291		__le64	resync_offset;	/* data before this offset (from data_offset) known to be in sync */
   292		__le32	sb_csum;	/* checksum up to devs[max_dev] */
   293		__le32	max_dev;	/* size of devs[] array to consider */
   294		__u8	pad3[64-32];	/* set to 0 when writing */
   295	
   296		/* device state information. Indexed by dev_number.
   297		 * 2 bytes per device
   298		 * Note there are no per-device state flags. State information is rolled
   299		 * into the 'roles' value.  If a device is spare or faulty, then it doesn't
   300		 * have a meaningful role.
   301		 */
   302		__le16	dev_roles[];	/* role in array, or 0xffff for a spare, or 0xfffe for faulty */
   303	};
   304	
   305	/* feature_map bits */
   306	#define MD_FEATURE_BITMAP_OFFSET	1
   307	#define	MD_FEATURE_RECOVERY_OFFSET	2 /* recovery_offset is present and
   308						   * must be honoured
   309						   */
   310	#define	MD_FEATURE_RESHAPE_ACTIVE	4
   311	#define	MD_FEATURE_BAD_BLOCKS		8 /* badblock list is not empty */
   312	#define	MD_FEATURE_REPLACEMENT		16 /* This device is replacing an
   313						    * active device with same 'role'.
   314						    * 'recovery_offset' is also set.
   315						    */
   316	#define	MD_FEATURE_RESHAPE_BACKWARDS	32 /* Reshape doesn't change number
   317						    * of devices, but is going
   318						    * backwards anyway.
   319						    */
   320	#define	MD_FEATURE_NEW_OFFSET		64 /* new_offset must be honoured */
   321	#define	MD_FEATURE_RECOVERY_BITMAP	128 /* recovery that is happening
   322						     * is guided by bitmap.
   323						     */
   324	#define	MD_FEATURE_CLUSTERED		256 /* clustered MD */
   325	#define	MD_FEATURE_JOURNAL		512 /* support write cache */
   326	#define	MD_FEATURE_PPL			1024 /* support PPL */
   327	#define	MD_FEATURE_MULTIPLE_PPLS	2048 /* support for multiple PPLs */
   328	#define	MD_FEATURE_RAID0_LAYOUT		4096 /* layout is meaningful for RAID0 */
   329	#define	MD_FEATURE_ALL			(MD_FEATURE_BITMAP_OFFSET	\
   330						|MD_FEATURE_RECOVERY_OFFSET	\
   331						|MD_FEATURE_RESHAPE_ACTIVE	\
   332						|MD_FEATURE_BAD_BLOCKS		\
   333						|MD_FEATURE_REPLACEMENT		\
   334						|MD_FEATURE_RESHAPE_BACKWARDS	\
   335						|MD_FEATURE_NEW_OFFSET		\
   336						|MD_FEATURE_RECOVERY_BITMAP	\
   337						|MD_FEATURE_CLUSTERED		\
   338						|MD_FEATURE_JOURNAL		\
   339						|MD_FEATURE_PPL			\
   340						|MD_FEATURE_MULTIPLE_PPLS	\
   341						|MD_FEATURE_RAID0_LAYOUT	\
   342						)
   343	
   344	struct r5l_payload_header {
   345		__le16 type;
   346		__le16 flags;
   347	} __attribute__ ((__packed__));
   348	
   349	enum r5l_payload_type {
   350		R5LOG_PAYLOAD_DATA = 0,
   351		R5LOG_PAYLOAD_PARITY = 1,
   352		R5LOG_PAYLOAD_FLUSH = 2,
   353	};
   354	
   355	struct r5l_payload_data_parity {
   356		struct r5l_payload_header header;
   357		__le32 size;		/* sector. data/parity size. each 4k
   358					 * has a checksum */
   359		__le64 location;	/* sector. For data, it's raid sector. For
   360					 * parity, it's stripe sector */
   361		__le32 checksum[];
   362	} __attribute__ ((__packed__));
   363	
   364	enum r5l_payload_data_parity_flag {
   365		R5LOG_PAYLOAD_FLAG_DISCARD = 1, /* payload is discard */
   366		/*
   367		 * RESHAPED/RESHAPING is only set when there is reshape activity. Note,
   368		 * both data/parity of a stripe should have the same flag set
   369		 *
   370		 * RESHAPED: reshape is running, and this stripe finished reshape
   371		 * RESHAPING: reshape is running, and this stripe isn't reshaped
   372		 */
   373		R5LOG_PAYLOAD_FLAG_RESHAPED = 2,
   374		R5LOG_PAYLOAD_FLAG_RESHAPING = 3,
   375	};
   376	
   377	struct r5l_payload_flush {
   378		struct r5l_payload_header header;
   379		__le32 size; /* flush_stripes size, bytes */
   380		__le64 flush_stripes[];
   381	} __attribute__ ((__packed__));
   382	
   383	enum r5l_payload_flush_flag {
   384		R5LOG_PAYLOAD_FLAG_FLUSH_STRIPE = 1, /* data represents whole stripe */
   385	};
   386	
   387	struct r5l_meta_block {
   388		__le32 magic;
   389		__le32 checksum;
   390		__u8 version;
   391		__u8 __zero_pading_1;
   392		__le16 __zero_pading_2;
   393		__le32 meta_size; /* whole size of the block */
   394	
   395		__le64 seq;
   396		__le64 position; /* sector, start from rdev->data_offset, current position */
   397		struct r5l_payload_header payloads[];
   398	} __attribute__ ((__packed__));
   399	
   400	#define R5LOG_VERSION 0x1
   401	#define R5LOG_MAGIC 0x6433c509
   402	
   403	struct ppl_header_entry {
   404		__le64 data_sector;	/* raid sector of the new data */
   405		__le32 pp_size;		/* length of partial parity */
   406		__le32 data_size;	/* length of data */
   407		__le32 parity_disk;	/* member disk containing parity */
   408		__le32 checksum;	/* checksum of partial parity data for this
   409					 * entry (~crc32c) */
   410	} __attribute__ ((__packed__));
   411	
   412	#define PPL_HEADER_SIZE 4096
   413	#define PPL_HDR_RESERVED 512
   414	#define PPL_HDR_ENTRY_SPACE \
   415		(PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(__le32) - sizeof(__le64))
   416	#define PPL_HDR_MAX_ENTRIES \
   417		(PPL_HDR_ENTRY_SPACE / sizeof(struct ppl_header_entry))
   418	
   419	struct ppl_header {
   420		__u8 reserved[PPL_HDR_RESERVED];/* reserved space, fill with 0xff */
   421		__le32 signature;		/* signature (family number of volume) */
   422		__le32 padding;			/* zero pad */
   423		__le64 generation;		/* generation number of the header */
   424		__le32 entries_count;		/* number of entries in entry array */
   425		__le32 checksum;		/* checksum of the header (~crc32c) */
   426		struct ppl_header_entry entries[PPL_HDR_MAX_ENTRIES];
   427	} __attribute__ ((__packed__));
   428	
   429	#endif