restore/inomap.h

/*
 * Copyright (c) 2000-2001 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef INOMAP_H
#define INOMAP_H

/* inomap.[hc] - inode map abstraction
 *
 * an inode map describes the inode numbers (inos) in a file system dump.
 * the map identifies which inos are in-use by the fs, which of those are
 * directories, and which are dumped.
 *
 * the map is represented as a list of map segments. a map segment is
 * a 64-bit starting ino and two 64-bit bitmaps. the bitmaps describe
 * the 64 inos beginning with the starting ino. two bits are available
 * for each ino.
 */

/* map state values
 */
#define MAP_INO_UNUSED	0       /* ino not in use by fs */
#define MAP_DIR_NOCHNG	1       /* dir, ino in use by fs, but not dumped */
#define MAP_NDR_NOCHNG	2       /* non-dir, ino in use by fs, but not dumped */
#define MAP_DIR_CHANGE	3       /* dir, changed since last dump */
#define MAP_NDR_CHANGE	4       /* non-dir, changed since last dump */
#define MAP_DIR_SUPPRT	5       /* dir, unchanged but needed for hierarchy */
#define MAP_NDR_NOREST	6       /* was MAP_NDR_CHANGE, but not to be restored */
#define MAP_RESERVED2	7       /* this state currently not used */

/* the inomap is implemented as a linked list of chunks. each chunk contains
 * an array of map segments. a map segment contains a start ino and a
 * bitmap of 64 3-bit state values (see MAP_... in inomap.h). the SEG_macros
 * index and manipulate the 3-bit state values.
 */
struct seg {
	xfs_ino_t base;
	uint64_t lobits;
	uint64_t mebits;
	uint64_t hibits;
};

typedef struct seg seg_t;

#define INOPERSEG	(sizeofmember(seg_t, lobits) * NBBY)

#define HNKSZ		(4 * PGSZ)
#define SEGPERHNK	((HNKSZ / sizeof(seg_t)) - 1)

struct hnk {
	seg_t seg[SEGPERHNK];
	xfs_ino_t maxino;
	struct hnk *nextp;
	char pad[sizeof(seg_t) - sizeof(xfs_ino_t) - sizeof(struct hnk *)];
};

typedef struct hnk hnk_t;

extern bool_t inomap_sync_pers(char *hkdir);
extern rv_t inomap_restore_pers(drive_t *drivep,
				 content_inode_hdr_t *scrhdrp,
				 char *hkdir);
extern void inomap_del_pers(char *hkdir);
extern void inomap_sanitize(void);
extern bool_t inomap_rst_needed(xfs_ino_t begino, xfs_ino_t endino);
extern void inomap_rst_add(xfs_ino_t ino);
extern void inomap_rst_del(xfs_ino_t ino);
extern rv_t inomap_discard(drive_t *drivep, content_inode_hdr_t *scrhdrp);
extern void inomap_cbiter(int mapstatemask,
			   bool_t (*cbfunc)(void *ctxp, xfs_ino_t ino),
			   void *ctxp);

#endif /* INOMAP_H */