include/uapi/linux/gfs2_ondisk.h

Source file repositories/reference/linux-study-clean/include/uapi/linux/gfs2_ondisk.h

File Facts

System
Linux kernel
Corpus path
include/uapi/linux/gfs2_ondisk.h
Extension
.h
Size
14769 bytes
Lines
543
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct gfs2_inum {
	__be64 no_formal_ino;
	__be64 no_addr;
};

/*
 * Generic metadata head structure
 * Every inplace buffer logged in the journal must start with this.
 */

#define GFS2_METATYPE_NONE	0
#define GFS2_METATYPE_SB	1
#define GFS2_METATYPE_RG	2
#define GFS2_METATYPE_RB	3
#define GFS2_METATYPE_DI	4
#define GFS2_METATYPE_IN	5
#define GFS2_METATYPE_LF	6
#define GFS2_METATYPE_JD	7
#define GFS2_METATYPE_LH	8
#define GFS2_METATYPE_LD	9
#define GFS2_METATYPE_LB	12
#define GFS2_METATYPE_EA	10
#define GFS2_METATYPE_ED	11
#define GFS2_METATYPE_QC	14

struct gfs2_meta_header {
	__be32 mh_magic;
	__be32 mh_type;
	__be64 __pad0;		/* Was generation number in gfs1 */
	__be32 mh_format;
	/* This union is to keep userspace happy */
	union {
		__be32 mh_jid;		/* Was incarnation number in gfs1 */
		__be32 __pad1;
	};
};

/*
 * super-block structure
 *
 * It's probably good if SIZEOF_SB <= GFS2_BASIC_BLOCK (512 bytes)
 *
 * Order is important, need to be able to read old superblocks to do on-disk
 * version upgrades.
 */

/* Address of superblock in GFS2 basic blocks */
#define GFS2_SB_ADDR		128

/* The lock number for the superblock (must be zero) */
#define GFS2_SB_LOCK		0

/* Requirement:  GFS2_LOCKNAME_LEN % 8 == 0
   Includes: the fencing zero at the end */
#define GFS2_LOCKNAME_LEN	64

struct gfs2_sb {
	struct gfs2_meta_header sb_header;

	__be32 sb_fs_format;
	__be32 sb_multihost_format;
	__u32  __pad0;	/* Was superblock flags in gfs1 */

	__be32 sb_bsize;
	__be32 sb_bsize_shift;
	__u32 __pad1;	/* Was journal segment size in gfs1 */

	struct gfs2_inum sb_master_dir; /* Was jindex dinode in gfs1 */
	struct gfs2_inum __pad2; /* Was rindex dinode in gfs1 */
	struct gfs2_inum sb_root_dir;

	char sb_lockproto[GFS2_LOCKNAME_LEN];
	char sb_locktable[GFS2_LOCKNAME_LEN];

	struct gfs2_inum __pad3; /* Was quota inode in gfs1 */
	struct gfs2_inum __pad4; /* Was licence inode in gfs1 */
#define GFS2_HAS_UUID 1
	__u8 sb_uuid[16]; /* The UUID, maybe 0 for backwards compat */
};

/*
 * resource index structure
 */

struct gfs2_rindex {
	__be64 ri_addr;	/* grp block disk address */
	__be32 ri_length;	/* length of rgrp header in fs blocks */
	__u32 __pad;

	__be64 ri_data0;	/* first data location */

Annotation

Implementation Notes