text: /*
   * Copyright (c) 2000-2006 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_BMAP_H__
  #define	__XFS_BMAP_H__
  
  struct getbmap;
  struct xfs_bmbt_irec;
  struct xfs_ifork;
  struct xfs_inode;
  struct xfs_mount;
  struct xfs_trans;
  
  extern kmem_zone_t	*xfs_bmap_free_item_zone;
  
  /*
   * List of extents to be free "later".
   * The list is kept sorted on xbf_startblock.
   */
  typedef struct xfs_bmap_free_item
  {
  	xfs_fsblock_t		xbfi_startblock;/* starting fs block number */
  	xfs_extlen_t		xbfi_blockcount;/* number of blocks in extent */
  	struct xfs_bmap_free_item *xbfi_next;	/* link to next entry */
  } xfs_bmap_free_item_t;
  
  /*
   * Header for free extent list.
   *
   * xbf_low is used by the allocator to activate the lowspace algorithm -
   * when free space is running low the extent allocator may choose to
   * allocate an extent from an AG without leaving sufficient space for
   * a btree split when inserting the new extent.  In this case the allocator
   * will enable the lowspace algorithm which is supposed to allow further
   * allocations (such as btree splits and newroots) to allocate from
   * sequential AGs.  In order to avoid locking AGs out of order the lowspace
   * algorithm will start searching for free space from AG 0.  If the correct
   * transaction reservations have been made then this algorithm will eventually
   * find all the space it needs.
   */
  typedef	struct xfs_bmap_free
  {
  	xfs_bmap_free_item_t	*xbf_first;	/* list of to-be-free extents */
  	int			xbf_count;	/* count of items on list */
  	int			xbf_low;	/* alloc in low mode */
  } xfs_bmap_free_t;
  
  #define	XFS_BMAP_MAX_NMAP	4
  
  /*
   * Flags for xfs_bmapi_*
   */
  #define XFS_BMAPI_ENTIRE	0x001	/* return entire extent, not trimmed */
  #define XFS_BMAPI_METADATA	0x002	/* mapping metadata not user data */
  #define XFS_BMAPI_ATTRFORK	0x004	/* use attribute fork not data */
  #define XFS_BMAPI_PREALLOC	0x008	/* preallocation op: unwritten space */
  #define XFS_BMAPI_IGSTATE	0x010	/* Ignore state - */
  					/* combine contig. space */
  #define XFS_BMAPI_CONTIG	0x020	/* must allocate only one extent */
  /*
   * unwritten extent conversion - this needs write cache flushing and no additional
   * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
   * from written to unwritten, otherwise convert from unwritten to written.
   */
  #define XFS_BMAPI_CONVERT	0x040
  
  #define XFS_BMAPI_FLAGS \
  	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
  	{ XFS_BMAPI_METADATA,	"METADATA" }, \
  	{ XFS_BMAPI_ATTRFORK,	"ATTRFORK" }, \
  	{ XFS_BMAPI_PREALLOC,	"PREALLOC" }, \
  	{ XFS_BMAPI_IGSTATE,	"IGSTATE" }, \
  	{ XFS_BMAPI_CONTIG,	"CONTIG" }, \
  	{ XFS_BMAPI_CONVERT,	"CONVERT" }
  
  
  static inline int xfs_bmapi_aflag(int w)
  {
  	return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
  }
  
  /*
   * Special values for xfs_bmbt_irec_t br_startblock field.
   */
  #define	DELAYSTARTBLOCK		((xfs_fsblock_t)-1LL)
  #define	HOLESTARTBLOCK		((xfs_fsblock_t)-2LL)
  
  static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
  {
  	((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
  		(flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
  }
  
  /*
   * Flags for xfs_bmap_add_extent*.
   */
  #define BMAP_LEFT_CONTIG	(1 << 0)
  #define BMAP_RIGHT_CONTIG	(1 << 1)
  #define BMAP_LEFT_FILLING	(1 << 2)
  #define BMAP_RIGHT_FILLING	(1 << 3)
  #define BMAP_LEFT_DELAY		(1 << 4)
  #define BMAP_RIGHT_DELAY	(1 << 5)
  #define BMAP_LEFT_VALID		(1 << 6)
  #define BMAP_RIGHT_VALID	(1 << 7)
  #define BMAP_ATTRFORK		(1 << 8)
  
  #define XFS_BMAP_EXT_FLAGS \
  	{ BMAP_LEFT_CONTIG,	"LC" }, \
  	{ BMAP_RIGHT_CONTIG,	"RC" }, \
  	{ BMAP_LEFT_FILLING,	"LF" }, \
  	{ BMAP_RIGHT_FILLING,	"RF" }, \
  	{ BMAP_ATTRFORK,	"ATTR" }
  
  
  /*
   * This macro is used to determine how many extents will be shifted
   * in one write transaction. We could require two splits,
   * an extent move on the first and an extent merge on the second,
   * So it is proper that one extent is shifted inside write transaction
   * at a time.
   */
  #define XFS_BMAP_MAX_SHIFT_EXTENTS	1
  
  #ifdef DEBUG
  void	xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
  		int whichfork, unsigned long caller_ip);
  #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)	\
  	xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
  #else
  #define	XFS_BMAP_TRACE_EXLIST(ip,c,w)
  #endif
  
  int	xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
  void	xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
  void	xfs_bmap_add_free(xfs_fsblock_t bno, xfs_filblks_t len,
  		struct xfs_bmap_free *flist, struct xfs_mount *mp);
  void	xfs_bmap_cancel(struct xfs_bmap_free *flist);
  void	xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
  int	xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
  		xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
  int	xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
  		xfs_fileoff_t *last_block, int whichfork);
  int	xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
  		int whichfork);
  int	xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
  int	xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
  		int whichfork);
  int	xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
  		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
  		int *nmap, int flags);
  int	xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
  		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
  		int *nmap, int flags);
  int	xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
  		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
  		xfs_fsblock_t *firstblock, xfs_extlen_t total,
  		struct xfs_bmbt_irec *mval, int *nmap,
  		struct xfs_bmap_free *flist);
  int	xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
  		xfs_fileoff_t bno, xfs_filblks_t len, int flags,
  		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
  		struct xfs_bmap_free *flist, int *done);
  int	xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
  		xfs_extnum_t num);
  uint	xfs_default_attroffset(struct xfs_inode *ip);
  int	xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
  		xfs_fileoff_t start_fsb, xfs_fileoff_t offset_shift_fsb,
  		int *done, xfs_fileoff_t *next_fsb, xfs_fsblock_t *firstblock,
  		struct xfs_bmap_free *flist, int num_exts);
  
  #endif	/* __XFS_BMAP_H__ */
  