fs/jfs/jfs_dinode.h

Source file repositories/reference/linux-study-clean/fs/jfs/jfs_dinode.h

File Facts

System
Linux kernel
Corpus path
fs/jfs/jfs_dinode.h
Extension
.h
Size
5097 bytes
Lines
170
Domain
Core OS
Bucket
VFS And Filesystem Core
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 dinode {
	/*
	 *	I. base area (128 bytes)
	 *	------------------------
	 *
	 * define generic/POSIX attributes
	 */
	__le32 di_inostamp;	/* 4: stamp to show inode belongs to fileset */
	__le32 di_fileset;	/* 4: fileset number */
	__le32 di_number;	/* 4: inode number, aka file serial number */
	__le32 di_gen;		/* 4: inode generation number */

	pxd_t di_ixpxd;		/* 8: inode extent descriptor */

	__le64 di_size;		/* 8: size */
	__le64 di_nblocks;	/* 8: number of blocks allocated */

	__le32 di_nlink;	/* 4: number of links to the object */

	__le32 di_uid;		/* 4: user id of owner */
	__le32 di_gid;		/* 4: group id of owner */

	__le32 di_mode;		/* 4: attribute, format and permission */

	struct timestruc_t di_atime;	/* 8: time last data accessed */
	struct timestruc_t di_ctime;	/* 8: time last status changed */
	struct timestruc_t di_mtime;	/* 8: time last data modified */
	struct timestruc_t di_otime;	/* 8: time created */

	dxd_t di_acl;		/* 16: acl descriptor */

	dxd_t di_ea;		/* 16: ea descriptor */

	__le32 di_next_index;	/* 4: Next available dir_table index */

	__le32 di_acltype;	/* 4: Type of ACL */

	/*
	 *	Extension Areas.
	 *
	 *	Historically, the inode was partitioned into 4 128-byte areas,
	 *	the last 3 being defined as unions which could have multiple
	 *	uses.  The first 96 bytes had been completely unused until
	 *	an index table was added to the directory.  It is now more
	 *	useful to describe the last 3/4 of the inode as a single
	 *	union.  We would probably be better off redesigning the
	 *	entire structure from scratch, but we don't want to break
	 *	commonality with OS/2's JFS at this time.
	 */
	union {
		struct {
			/*
			 * This table contains the information needed to
			 * find a directory entry from a 32-bit index.
			 * If the index is small enough, the table is inline,
			 * otherwise, an x-tree root overlays this table
			 */
			struct dir_table_slot _table[12]; /* 96: inline */

			dtroot_t _dtroot;		/* 288: dtree root */
		} _dir;					/* (384) */
#define di_dirtable	u._dir._table
#define di_dtroot	u._dir._dtroot
#define di_parent	di_dtroot.header.idotdot
#define di_DASD		di_dtroot.header.DASD

		struct {
			union {
				u8 _data[96];		/* 96: unused */
				struct {
					void *_imap;	/* 4: unused */
					__le32 _gengen;	/* 4: generator */
				} _imap;
			} _u1;				/* 96: */
#define di_gengen	u._file._u1._imap._gengen

			union {
				xtroot_t _xtroot;
				struct {
					u8 unused[16];	/* 16: */
					dxd_t _dxd;	/* 16: */
					union {
						/*
						 * The fast symlink area
						 * is expected to overflow
						 * into _inlineea when
						 * needed (which will clear
						 * INLINEEA).
						 */
						struct {

Annotation

Implementation Notes