fs/nilfs2/segbuf.h

Source file repositories/reference/linux-study-clean/fs/nilfs2/segbuf.h

File Facts

System
Linux kernel
Corpus path
fs/nilfs2/segbuf.h
Extension
.h
Size
5631 bytes
Lines
173
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 nilfs_segsum_info {
	unsigned int		flags;
	unsigned long		nfinfo;
	unsigned long		nblocks;
	unsigned long		nsumblk;
	unsigned long		sumbytes;
	unsigned long		nfileblk;
	u64			seg_seq;
	__u64			cno;
	time64_t		ctime;
	sector_t		next;
};

/**
 * struct nilfs_segment_buffer - Segment buffer
 * @sb_super: back pointer to a superblock struct
 * @sb_list: List head to chain this structure
 * @sb_sum: On-memory segment summary
 * @sb_segnum: Index number of the full segment
 * @sb_nextnum: Index number of the next full segment
 * @sb_fseg_start: Start block number of the full segment
 * @sb_fseg_end: End block number of the full segment
 * @sb_pseg_start: Disk block number of partial segment
 * @sb_rest_blocks: Number of residual blocks in the current segment
 * @sb_segsum_buffers: List of buffers for segment summaries
 * @sb_payload_buffers: List of buffers for segment payload
 * @sb_super_root: Pointer to buffer storing a super root block (if exists)
 * @sb_nbio: Number of flying bio requests
 * @sb_err: I/O error status
 * @sb_bio_event: Completion event of log writing
 */
struct nilfs_segment_buffer {
	struct super_block     *sb_super;
	struct list_head	sb_list;

	/* Segment information */
	struct nilfs_segsum_info sb_sum;
	__u64			sb_segnum;
	__u64			sb_nextnum;
	sector_t		sb_fseg_start, sb_fseg_end;
	sector_t		sb_pseg_start;
	unsigned int		sb_rest_blocks;

	/* Buffers */
	struct list_head	sb_segsum_buffers;
	struct list_head	sb_payload_buffers; /* including super root */
	struct buffer_head     *sb_super_root;

	/* io status */
	int			sb_nbio;
	atomic_t		sb_err;
	struct completion	sb_bio_event;
};

#define NILFS_LIST_SEGBUF(head)  \
	list_entry((head), struct nilfs_segment_buffer, sb_list)
#define NILFS_NEXT_SEGBUF(segbuf)  NILFS_LIST_SEGBUF((segbuf)->sb_list.next)
#define NILFS_PREV_SEGBUF(segbuf)  NILFS_LIST_SEGBUF((segbuf)->sb_list.prev)
#define NILFS_LAST_SEGBUF(head)    NILFS_LIST_SEGBUF((head)->prev)
#define NILFS_FIRST_SEGBUF(head)   NILFS_LIST_SEGBUF((head)->next)
#define NILFS_SEGBUF_IS_LAST(segbuf, head)  ((segbuf)->sb_list.next == (head))

#define nilfs_for_each_segbuf_before(s, t, h) \
	for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \
	     (s) = NILFS_NEXT_SEGBUF(s))

#define NILFS_SEGBUF_FIRST_BH(head)  \
	(list_entry((head)->next, struct buffer_head, b_assoc_buffers))
#define NILFS_SEGBUF_NEXT_BH(bh)  \
	(list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \
		    b_assoc_buffers))
#define NILFS_SEGBUF_BH_IS_LAST(bh, head)  ((bh)->b_assoc_buffers.next == head)

extern struct kmem_cache *nilfs_segbuf_cachep;

struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *);
void nilfs_segbuf_free(struct nilfs_segment_buffer *);
void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
		      struct the_nilfs *);
void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
			   struct nilfs_segment_buffer *prev);
void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
				  struct the_nilfs *);
int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned int, time64_t,
		       __u64);
int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *);
int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *,
				struct buffer_head **);
void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *);

Annotation

Implementation Notes