Return to xfs_ialloc.h CVS log

Up to [Development] / xfs-linux-nodel

Change "functional" macros' names from lower to uppercase, for consistency
with everything else.

#ifndef _FS_XFS_IALLOC_H
#define	_FS_XFS_IALLOC_H

#ident	"$Revision: 1.16 $"

/*
 * Allocation parameters.
 * These control how many inodes are allocated at once.
 */
#define	XFS_IALLOC_MAX_EVER_BLOCKS	16
#define	XFS_IALLOC_MAX_EVER_INODES	256
#define	XFS_IALLOC_MAX_EVER(mp,a)	\
	XFS_EXTLEN_MIN(XFS_IALLOC_MAX_EVER_BLOCKS, \
		XFS_IALLOC_MAX_EVER_INODES >> (mp)->m_sb.sb_inopblog)

#define	XFS_IALLOC_MIN_ALLOC(mp,a)	1
#define XFS_IALLOC_MAX_ALLOC(mp,a)	\
	(((a)->agi_count >> (mp)->m_sb.sb_inopblog) >= \
	 XFS_IALLOC_MAX_EVER(mp,a) ? \
		XFS_IALLOC_MAX_EVER(mp,a) : \
		((a)->agi_count ? \
			((a)->agi_count >> (mp)->m_sb.sb_inopblog) : 1))

/*
 * Make an inode pointer out of the buffer/offset.
 */
#define	XFS_MAKE_IPTR(mp,b,o) \
	((xfs_dinode_t *)((b)->b_un.b_addr + ((o) << (mp)->m_sb.sb_inodelog)))

/*
 * Prototypes for visible xfs_ialloc.c routines.
 */

/*
 * Inode allocation takes place in 2 parts: xfs_dialloc_ino() and
 * xfs_dialloc_finish().  xfs_dialloc_ino() takes care of allocating
 * any space needed for new inodes and picks the inode to be allocated.
 * It then returns the inode number of the chosen inode and the agi buf
 * for the allocation group of the chosen inode.  The second part is
 * a call to xfs_dialloc_finish() to actually mark the chosen inode
 * allocated on disk.  This separation is needed for lock ordering between
 * the in-core inode and the on-disk inode buffer as described below.
 *
 * Mode is used to tell whether the new inode will need space, and whether
 * it is a directory.
 * The sameag flag is used by mkfs only, to force the root directory
 * inode into the first allocation group.
 *
 * To work within the constraint of one allocation per transaction,
 * xfs_dialloc_ino() is designed to be called twice if it has to do an
 * allocation to replenish the inode freelist.  If an inode is 
 * available without an allocation, agbuf would be set to the current
 * agbuf and alloc_done set to false.
 * If an allocation needed to be done, agbuf would be set to the
 * header of the freelist and alloc_done set to true.  The caller
 * should then commit the current transaction and allocate a new
 * transaction.  xfs_dialloc_ino() should then be called again with
 * the agbuf value returned from the previous call.
 *
 * Once we successfully pick an inode its number is returned and the
 * IO_agbuf parameter contains the ag_buf for the inode's ag.  The caller
 * should get its reference to the in-core inode/vnode for the given ino
 * and then call xfs_dialloc_finish() to finalize the allocation.  This
 * must be done to satisfy the ordering of the inode/vnode locking with
 * that of the on-disk inode's buffer.  Since xfs_reclaim() must be able
 * to flush a potentially free inode, it forces the order of inode/vnode
 * locking before inode buffer locking.
 *
 * agbuf should be set to NULL on the first call.
 */
xfs_ino_t				/* inode number allocated */
xfs_dialloc_ino(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_ino_t	parent,		/* parent inode (directory) */
	int		sameag,		/* 1 => must be in same a.g. */
	mode_t		mode,		/* mode bits for new inode */
	buf_t		**agbuf,	/* buf for ag.inode freelist header */
	boolean_t	*alloc_done);	/* an allocation was done to replenish
					   the inode freelist. */
/*
 * Finalize the allocation of an on-disk inode.  We need the
 * inode number returned by a previous call to xfs_dialloc_ino()
 * and the agi buffer returned in that call as well.  Here we
 * actually remove the on-disk inode from the free list and modify
 * the count of free inodes in the agi.
 *
 * We didn't do this earlier as part of xfs_dialloc_ino(), because the
 * in-core inode must be obtained BEFORE the on-disk buffer.  This
 * ordering is forced by xfs_reclaim() needing to flush out a dirty
 * inode (thereby locking the buffer for its on-disk copy) after the
 * vnode's RECLAIM bit is set and the inode is locked.
 */
void
xfs_dialloc_finish(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_ino_t	ino,		/* ino returned by xfs_dialloc_ino */
	buf_t		*agbuf);	/* agi buf from xfs_dialloc_ino */
					   
/*
 * Return the next (past agino) inode on the freelist for this allocation group
 * (given by agbuf).  Used to traverse the whole list, e.g. for printing.
 */
xfs_agino_t				/* a.g. inode next on freelist */
xfs_dialloc_next_free(
	xfs_mount_t	*mp,		/* filesystem mount structure */
	xfs_trans_t	*tp,		/* transaction pointer */
	buf_t		*agbuf,		/* buffer for ag.inode header */
	xfs_agino_t	agino);		/* inode to get next free for */

/*
 * Free disk inode.  Carefully avoids touching the incore inode, all
 * manipulations incore are the caller's responsibility.
 */
void
xfs_difree(
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_ino_t	inode);		/* inode to be freed */

/*
 * Return the location of the inode in bno/off, for mapping it into a buffer.
 */
void
xfs_dilocate(
	xfs_mount_t	*mp,		/* file system mount structure */
	xfs_trans_t	*tp,		/* transaction pointer */
	xfs_ino_t	ino,		/* inode to locate */
	xfs_fsblock_t	*bno,		/* output: block containing inode */
	int		*off);		/* output: index in block of inode */

#endif	/* !_FS_XFS_IALLOC_H */