xfs_inode.h

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/*
 * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 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.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */
#ifndef	__XFS_INODE_H__
#define	__XFS_INODE_H__

/*
 * File incore extent information, present for each of data & attr forks.
 */
#define	XFS_INLINE_EXTS	2
#define	XFS_INLINE_DATA	32
typedef struct xfs_ifork {
	int			if_bytes;	/* bytes in if_u1 */
	int			if_real_bytes;	/* bytes allocated in if_u1 */
	xfs_bmbt_block_t	*if_broot;	/* file's incore btree root */
	short			if_broot_bytes;	/* bytes allocated for root */
	unsigned char		if_flags;	/* per-fork flags */
	unsigned char		if_ext_max;	/* max # of extent records */
	xfs_extnum_t		if_lastex;	/* last if_extents used */
	union {
		xfs_bmbt_rec_t	*if_extents;	/* linear map file exts */
		char		*if_data;	/* inline file data */
	} if_u1;
	union {
		xfs_bmbt_rec_t	if_inline_ext[XFS_INLINE_EXTS];
						/* very small file extents */
		char		if_inline_data[XFS_INLINE_DATA];
						/* very small file data */
		xfs_dev_t	if_rdev;	/* dev number if special */
		uuid_t		if_uuid;	/* mount point value */
	} if_u2;
} xfs_ifork_t;

/*
 * Flags for xfs_ichgtime().
 */
#define	XFS_ICHGTIME_MOD	0x1	/* data fork modification timestamp */
#define	XFS_ICHGTIME_ACC	0x2	/* data fork access timestamp */
#define	XFS_ICHGTIME_CHG	0x4	/* inode field change timestamp */

/*
 * Per-fork incore inode flags.
 */
#define	XFS_IFINLINE	0x0001	/* Inline data is read in */
#define	XFS_IFEXTENTS	0x0002	/* All extent pointers are read in */
#define	XFS_IFBROOT	0x0004	/* i_broot points to the bmap b-tree root */

/*
 * Flags for xfs_imap() and xfs_dilocate().
 */
#define	XFS_IMAP_LOOKUP		0x1

/*
 * Maximum number of extent pointers in if_u1.if_extents.
 */
#define	XFS_MAX_INCORE_EXTENTS	32768


#ifdef __KERNEL__
struct bhv_desc;
struct cred;
struct ktrace;
struct vnode;
struct xfs_buf;
struct xfs_bmap_free;
struct xfs_bmbt_irec;
struct xfs_bmbt_block;
struct xfs_inode;
struct xfs_inode_log_item;
struct xfs_mount;
struct xfs_trans;
struct xfs_dquot;

#if defined(XFS_ILOCK_TRACE)
#define XFS_ILOCK_KTRACE_SIZE	32
extern ktrace_t *xfs_ilock_trace_buf;
extern void xfs_ilock_trace(struct xfs_inode *, int, unsigned int, inst_t *);
#else
#define	xfs_ilock_trace(i,n,f,ra)
#endif

/*
 * This structure is used to communicate which extents of a file
 * were holes when a write started from xfs_write_file() to
 * xfs_strat_read().  This is necessary so that we can know which
 * blocks need to be zeroed when they are read in in xfs_strat_read()
 * if they weren\'t allocated when the buffer given to xfs_strat_read()
 * was mapped.
 *
 * We keep a list of these attached to the inode.  The list is
 * protected by the inode lock and the fact that the io lock is
 * held exclusively by writers.
 */
typedef struct xfs_gap {
	struct xfs_gap	*xg_next;
	xfs_fileoff_t	xg_offset_fsb;
	xfs_extlen_t	xg_count_fsb;
} xfs_gap_t;

typedef struct dm_attrs_s {
	__uint32_t	da_dmevmask;	/* DMIG event mask */
	__uint16_t	da_dmstate;	/* DMIG state info */
	__uint16_t	da_pad;		/* DMIG extra padding */
} dm_attrs_t;

typedef struct xfs_iocore {
	void			*io_obj;	/* pointer to container
						 * inode or dcxvn structure */
	struct xfs_mount	*io_mount;	/* fs mount struct ptr */
#ifdef DEBUG
	mrlock_t		*io_lock;	/* inode IO lock */
	mrlock_t		*io_iolock;	/* inode IO lock */
#endif

	/* I/O state */
	xfs_fsize_t		io_new_size;	/* sz when write completes */

	/* Miscellaneous state. */
	unsigned int		io_flags;	/* IO related flags */

	/* DMAPI state */
	dm_attrs_t		io_dmattrs;

} xfs_iocore_t;

#define        io_dmevmask     io_dmattrs.da_dmevmask
#define        io_dmstate      io_dmattrs.da_dmstate

#define XFS_IO_INODE(io)	((xfs_inode_t *) ((io)->io_obj))
#define XFS_IO_DCXVN(io)	((dcxvn_t *) ((io)->io_obj))

/*
 * Flags in the flags field
 */

#define XFS_IOCORE_RT		0x1

/*
 * xfs_iocore prototypes
 */

extern void xfs_iocore_inode_init(struct xfs_inode *);
extern void xfs_iocore_inode_reinit(struct xfs_inode *);


/*
 * This is the type used in the xfs inode hash table.
 * An array of these is allocated for each mounted
 * file system to hash the inodes for that file system.
 */
typedef struct xfs_ihash {
	struct xfs_inode	*ih_next;
	rwlock_t		ih_lock;
	uint			ih_version;
} xfs_ihash_t;

/*
 * Inode hashing and hash bucket locking.
 */
#define XFS_BUCKETS(mp) (37*(mp)->m_sb.sb_agcount-1)
#define XFS_IHASH(mp,ino) ((mp)->m_ihash + (((uint)(ino)) % (mp)->m_ihsize))

/*
 * This is the xfs inode cluster hash.  This hash is used by xfs_iflush to
 * find inodes that share a cluster and can be flushed to disk at the same
 * time.
 */

typedef struct xfs_chashlist {
	struct xfs_chashlist	*chl_next;
	struct xfs_inode	*chl_ip;
	xfs_daddr_t		chl_blkno;	/* starting block number of
						 * the cluster */
	struct xfs_buf		*chl_buf;	/* the inode buffer */
} xfs_chashlist_t;

typedef struct xfs_chash {
	xfs_chashlist_t		*ch_list;
	lock_t			ch_lock;
} xfs_chash_t;


/*
 * This is the xfs in-core inode structure.
 * Most of the on-disk inode is embedded in the i_d field.
 *
 * The extent pointers/inline file space, however, are managed
 * separately.  The memory for this information is pointed to by
 * the if_u1 unions depending on the type of the data.
 * This is used to linearize the array of extents for fast in-core
 * access.  This is used until the file's number of extents
 * surpasses XFS_MAX_INCORE_EXTENTS, at which point all extent pointers
 * are accessed through the buffer cache.
 *
 * Other state kept in the in-core inode is used for identification,
 * locking, transactional updating, etc of the inode.
 *
 * Generally, we do not want to hold the i_rlock while holding the
 * i_ilock. Hierarchy is i_iolock followed by i_rlock.
 *
 * xfs_iptr_t contains all the inode fields upto and including the
 * i_mnext and i_mprev fields, it is used as a marker in the inode
 * chain off the mount structure by xfs_sync calls.
 */

typedef struct {
	struct xfs_ihash	*ip_hash;	/* pointer to hash header */
	struct xfs_inode	*ip_next;	/* inode hash link forw */
	struct xfs_inode	*ip_mnext;	/* next inode in mount list */
	struct xfs_inode	*ip_mprev;	/* ptr to prev inode */
	struct xfs_inode	**ip_prevp;	/* ptr to prev i_next */
	struct xfs_mount	*ip_mount;	/* fs mount struct ptr */
} xfs_iptr_t;

typedef struct xfs_inode {
	/* Inode linking and identification information. */
	struct xfs_ihash	*i_hash;	/* pointer to hash header */
	struct xfs_inode	*i_next;	/* inode hash link forw */
	struct xfs_inode	*i_mnext;	/* next inode in mount list */
	struct xfs_inode	*i_mprev;	/* ptr to prev inode */
	struct xfs_inode	**i_prevp;	/* ptr to prev i_next */
	struct xfs_mount	*i_mount;	/* fs mount struct ptr */
	struct list_head	i_reclaim;	/* reclaim list */
	struct bhv_desc		i_bhv_desc;	/* inode behavior descriptor*/
	struct xfs_dquot	*i_udquot;	/* user dquot */
	struct xfs_dquot	*i_gdquot;	/* group dquot */

	/* Inode location stuff */
	xfs_ino_t		i_ino;		/* inode number (agno/agino)*/
	xfs_daddr_t		i_blkno;	/* blkno of inode buffer */
	ushort			i_len;		/* len of inode buffer */
	ushort			i_boffset;	/* off of inode in buffer */

	/* Extent information. */
	xfs_ifork_t		*i_afp;		/* attribute fork pointer */
	xfs_ifork_t		i_df;		/* data fork */

	/* Transaction and locking information. */
	struct xfs_trans	*i_transp;	/* ptr to owning transaction*/
	struct xfs_inode_log_item *i_itemp;	/* logging information */
	mrlock_t		i_lock;		/* inode lock */
	mrlock_t		i_iolock;	/* inode IO lock */
	sema_t			i_flock;	/* inode flush lock */
	atomic_t		i_pincount;	/* inode pin count */
	wait_queue_head_t	i_ipin_wait;	/* inode pinning wait queue */
#ifdef HAVE_REFCACHE
	struct xfs_inode	**i_refcache;	/* ptr to entry in ref cache */
	struct xfs_inode	*i_release;	/* inode to unref */
#endif
	/* I/O state */
	xfs_iocore_t		i_iocore;	/* I/O core */