fs/freevxfs/vxfs_dir.h

Source file repositories/reference/linux-study-clean/fs/freevxfs/vxfs_dir.h

File Facts

System
Linux kernel
Corpus path
fs/freevxfs/vxfs_dir.h
Extension
.h
Size
1893 bytes
Lines
69
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 vxfs_dirblk {
	__fs16		d_free;		/* free space in dirblock */
	__fs16		d_nhash;	/* no of hash chains */
	__fs16		d_hash[];	/* hash chain */
};

/*
 * VXFS_NAMELEN is the maximum length of the d_name field
 *	of an VxFS directory entry.
 */
#define VXFS_NAMELEN	256

/*
 * VxFS directory entry.
 */
struct vxfs_direct {
	__fs32		d_ino;			/* inode number */
	__fs16		d_reclen;		/* record length */
	__fs16		d_namelen;		/* d_name length */
	__fs16		d_hashnext;		/* next hash entry */
	char		d_name[VXFS_NAMELEN];	/* name */
};

/*
 * VXFS_DIRPAD defines the directory entry boundaries, is _must_ be
 *	a multiple of four.
 * VXFS_NAMEMIN is the length of a directory entry with a NULL d_name.
 * VXFS_DIRROUND is an internal macros that rounds a length to a value
 *	usable for directory sizes.
 * VXFS_DIRLEN calculates the directory entry size for an entry with
 *	a d_name with size len.
 */
#define VXFS_DIRPAD		4
#define VXFS_NAMEMIN		offsetof(struct vxfs_direct, d_name)
#define VXFS_DIRROUND(len)	((VXFS_DIRPAD + (len) - 1) & ~(VXFS_DIRPAD -1))
#define VXFS_DIRLEN(len)	(VXFS_DIRROUND(VXFS_NAMEMIN + (len)))

/*
 * VXFS_DIRBLKOV is the overhead of a specific dirblock.
 */
#define VXFS_DIRBLKOV(sbi, dbp)	\
	((sizeof(short) * fs16_to_cpu(sbi, dbp->d_nhash)) + 4)

#endif /* _VXFS_DIR_H_ */

Annotation

Implementation Notes