fs/ext4/fsmap.h

Source file repositories/reference/linux-study-clean/fs/ext4/fsmap.h

File Facts

System
Linux kernel
Corpus path
fs/ext4/fsmap.h
Extension
.h
Size
2042 bytes
Lines
57
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 ext4_fsmap {
	struct list_head	fmr_list;
	dev_t		fmr_device;	/* device id */
	uint32_t	fmr_flags;	/* mapping flags */
	uint64_t	fmr_physical;	/* device offset of segment */
	uint64_t	fmr_owner;	/* owner id */
	uint64_t	fmr_length;	/* length of segment, blocks */
};

struct ext4_fsmap_head {
	uint32_t	fmh_iflags;	/* control flags */
	uint32_t	fmh_oflags;	/* output flags */
	unsigned int	fmh_count;	/* # of entries in array incl. input */
	unsigned int	fmh_entries;	/* # of entries filled in (output). */

	struct ext4_fsmap fmh_keys[2];	/* low and high keys */
};

void ext4_fsmap_from_internal(struct super_block *sb, struct fsmap *dest,
		struct ext4_fsmap *src);
void ext4_fsmap_to_internal(struct super_block *sb, struct ext4_fsmap *dest,
		struct fsmap *src);

/* fsmap to userspace formatter - copy to user & advance pointer */
typedef int (*ext4_fsmap_format_t)(struct ext4_fsmap *, void *);

int ext4_getfsmap(struct super_block *sb, struct ext4_fsmap_head *head,
		ext4_fsmap_format_t formatter, void *arg);

#define EXT4_QUERY_RANGE_ABORT		1
#define EXT4_QUERY_RANGE_CONTINUE	0

/*	fmr_owner special values for FS_IOC_GETFSMAP; some share w/ XFS */
#define EXT4_FMR_OWN_FREE	FMR_OWN_FREE      /* free space */
#define EXT4_FMR_OWN_UNKNOWN	FMR_OWN_UNKNOWN   /* unknown owner */
#define EXT4_FMR_OWN_FS		FMR_OWNER('X', 1) /* static fs metadata */
#define EXT4_FMR_OWN_LOG	FMR_OWNER('X', 2) /* journalling log */
#define EXT4_FMR_OWN_INODES	FMR_OWNER('X', 5) /* inodes */
#define EXT4_FMR_OWN_GDT	FMR_OWNER('f', 1) /* group descriptors */
#define EXT4_FMR_OWN_RESV_GDT	FMR_OWNER('f', 2) /* reserved gdt blocks */
#define EXT4_FMR_OWN_BLKBM	FMR_OWNER('f', 3) /* block bitmap */
#define EXT4_FMR_OWN_INOBM	FMR_OWNER('f', 4) /* inode bitmap */

#endif /* __EXT4_FSMAP_H__ */

Annotation

Implementation Notes