/*

   * Copyright (c) 2000,2005 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 __XFS_IALLOC_H__
  #define	__XFS_IALLOC_H__
  
  struct xfs_buf;
  struct xfs_dinode;
  struct xfs_mount;
  struct xfs_trans;
  
  /*
   * Allocation parameters for inode allocation.
   */

  #define	XFS_IALLOC_INODES(mp)	(mp)->m_ialloc_inos
  #define	XFS_IALLOC_BLOCKS(mp)	(mp)->m_ialloc_blks

  
  /*
   * For small block file systems, move inodes in clusters of this size.
   * When we don't have a lot of memory, however, we go a bit smaller
   * to reduce the number of AGI and ialloc btree blocks we need to keep
   * around for xfs_dilocate().  We choose which one to use in
   * xfs_mount_int().
   */
  #define	XFS_INODE_BIG_CLUSTER_SIZE	8192
  #define	XFS_INODE_SMALL_CLUSTER_SIZE	4096
  #define	XFS_INODE_CLUSTER_SIZE(mp)	(mp)->m_inode_cluster_size
  
  /*
   * Make an inode pointer out of the buffer/offset.
   */

  #define	XFS_MAKE_IPTR(mp,b,o)		xfs_make_iptr(mp,b,o)

  static inline struct xfs_dinode *
  xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
  {
  	return (xfs_dinode_t *)
  		(xfs_buf_offset(b, o << (mp)->m_sb.sb_inodelog));
  }

  
  /*
   * Find a free (set) bit in the inode bitmask.
   */

  #define	XFS_IALLOC_FIND_FREE(fp)	xfs_ialloc_find_free(fp)

  static inline int xfs_ialloc_find_free(xfs_inofree_t *fp)
  {
  	return xfs_lowbit64(*fp);
  }

  
  
  #ifdef __KERNEL__

  /*
   * Allocate an inode on disk.
   * Mode is used to tell whether the new inode will need space, and whether
   * it is a directory.
   *
   * To work within the constraint of one allocation per transaction,
   * xfs_dialloc() is designed to be called twice if it has to do an
   * allocation to make more free inodes.  If an inode is
   * available without an allocation, agbp would be set to the current
   * agbp and alloc_done set to false.
   * If an allocation needed to be done, agbp would be set to the
   * inode header of the allocation group and alloc_done set to true.
   * The caller should then commit the current transaction and allocate a new
   * transaction.  xfs_dialloc() should then be called again with
   * the agbp value returned from the previous call.
   *
   * Once we successfully pick an inode its number is returned and the
   * on-disk data structures are updated.  The inode itself is not read
   * in, since doing so would break ordering constraints with xfs_reclaim.
   *
   * *agbp should be set to NULL on the first call, *alloc_done set to FALSE.
   */
  int					/* error */
  xfs_dialloc(
  	struct xfs_trans *tp,		/* transaction pointer */
  	xfs_ino_t	parent,		/* parent inode (directory) */
  	mode_t		mode,		/* mode bits for new inode */
  	int		okalloc,	/* ok to allocate more space */
  	struct xfs_buf	**agbp,		/* buf for a.g. inode header */
  	boolean_t	*alloc_done,	/* an allocation was done to replenish
  					   the free inodes */
  	xfs_ino_t	*inop);		/* inode number allocated */
  
  /*
   * Free disk inode.  Carefully avoids touching the incore inode, all
   * manipulations incore are the caller's responsibility.
   * The on-disk inode is not changed by this operation, only the
   * btree (free inode mask) is changed.
   */
  int					/* error */
  xfs_difree(
  	struct xfs_trans *tp,		/* transaction pointer */
  	xfs_ino_t	inode,		/* inode to be freed */
  	struct xfs_bmap_free *flist,	/* extents to free */
  	int		*delete,	/* set if inode cluster was deleted */
  	xfs_ino_t	*first_ino);	/* first inode in deleted cluster */
  
  /*
   * Return the location of the inode in bno/len/off,
   * for mapping it into a buffer.
   */
  int
  xfs_dilocate(
  	struct xfs_mount *mp,		/* file system mount structure */
  	struct xfs_trans *tp,		/* transaction pointer */
  	xfs_ino_t	ino,		/* inode to locate */
  	xfs_fsblock_t	*bno,		/* output: block containing inode */
  	int		*len,		/* output: num blocks in cluster*/
  	int		*off,		/* output: index in block of inode */
  	uint		flags);		/* flags for inode btree lookup */
  
  /*
   * Compute and fill in value of m_in_maxlevels.
   */
  void
  xfs_ialloc_compute_maxlevels(
  	struct xfs_mount *mp);		/* file system mount structure */
  
  /*
   * Log specified fields for the ag hdr (inode section)
   */
  void
  xfs_ialloc_log_agi(
  	struct xfs_trans *tp,		/* transaction pointer */
  	struct xfs_buf	*bp,		/* allocation group header buffer */
  	int		fields);	/* bitmask of fields to log */
  
  /*
   * Read in the allocation group header (inode allocation section)
   */
  int					/* error */
  xfs_ialloc_read_agi(
  	struct xfs_mount *mp,		/* file system mount structure */
  	struct xfs_trans *tp,		/* transaction pointer */
  	xfs_agnumber_t	agno,		/* allocation group number */
  	struct xfs_buf	**bpp);		/* allocation group hdr buf */

  /*
   * Read in the allocation group header to initialise the per-ag data
   * in the mount structure
   */
  int
  xfs_ialloc_pagi_init(
  	struct xfs_mount *mp,		/* file system mount structure */
  	struct xfs_trans *tp,		/* transaction pointer */
          xfs_agnumber_t  agno);		/* allocation group number */

  #endif	/* __KERNEL__ */
  
  #endif	/* __XFS_IALLOC_H__ */