/*

   * Copyright (c) 2000,2002-2003,2005 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_ATTR_H__
  #define	__XFS_ATTR_H__

  struct xfs_inode;
  struct xfs_da_args;
  struct xfs_attr_list_context;

  /*

   * Large attribute lists are structured around Btrees where all the data
   * elements are in the leaf nodes.  Attribute names are hashed into an int,
   * then that int is used as the index into the Btree.  Since the hashval
   * of an attribute name may not be unique, we may have duplicate keys.
   * The internal links in the Btree are logical block offsets into the file.
   *
   * Small attribute lists use a different format and are packed as tightly
   * as possible so as to fit into the literal area of the inode.
   */
  
  /*========================================================================
   * External interfaces
   *========================================================================*/

  
  #define ATTR_DONTFOLLOW	0x0001	/* -- unused, from IRIX -- */
  #define ATTR_ROOT	0x0002	/* use attrs in root (trusted) namespace */
  #define ATTR_TRUST	0x0004	/* -- unused, from IRIX -- */
  #define ATTR_SECURE	0x0008	/* use attrs in security namespace */
  #define ATTR_CREATE	0x0010	/* pure create: fail if attr already exists */
  #define ATTR_REPLACE	0x0020	/* pure set: fail if attr does not exist */

  #define ATTR_KERNOTIME	0x1000	/* [kernel] don't update inode timestamps */
  #define ATTR_KERNOVAL	0x2000	/* [kernel] get attr size only, not value */

  #define XFS_ATTR_FLAGS \
  	{ ATTR_DONTFOLLOW, 	"DONTFOLLOW" }, \
  	{ ATTR_ROOT,		"ROOT" }, \
  	{ ATTR_TRUST,		"TRUST" }, \
  	{ ATTR_SECURE,		"SECURE" }, \
  	{ ATTR_CREATE,		"CREATE" }, \
  	{ ATTR_REPLACE,		"REPLACE" }, \
  	{ ATTR_KERNOTIME,	"KERNOTIME" }, \
  	{ ATTR_KERNOVAL,	"KERNOVAL" }

  /*
   * The maximum size (into the kernel or returned from the kernel) of an
   * attribute value or the buffer used for an attr_list() call.  Larger
   * sizes will result in an ERANGE return code.
   */
  #define	ATTR_MAX_VALUELEN	(64*1024)	/* max length of a value */
  
  /*
   * Define how lists of attribute names are returned to the user from
   * the attr_list() call.  A large, 32bit aligned, buffer is passed in
   * along with its size.  We put an array of offsets at the top that each
   * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
   */
  typedef struct attrlist {
  	__s32	al_count;	/* number of entries in attrlist */
  	__s32	al_more;	/* T/F: more attrs (do call again) */
  	__s32	al_offset[1];	/* byte offsets of attrs [var-sized] */
  } attrlist_t;
  
  /*
   * Show the interesting info about one attribute.  This is what the
   * al_offset[i] entry points to.
   */
  typedef struct attrlist_ent {	/* data from attr_list() */
  	__u32	a_valuelen;	/* number bytes in value of attr */
  	char	a_name[1];	/* attr name (NULL terminated) */
  } attrlist_ent_t;
  
  /*
   * Given a pointer to the (char*) buffer containing the attr_list() result,
   * and an index, return a pointer to the indicated attribute in the buffer.
   */
  #define	ATTR_ENTRY(buffer, index)		\
  	((attrlist_ent_t *)			\
  	 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ])
  
  /*

   * Kernel-internal version of the attrlist cursor.
   */
  typedef struct attrlist_cursor_kern {
  	__u32	hashval;	/* hash value of next entry to add */
  	__u32	blkno;		/* block containing entry (suggestion) */
  	__u32	offset;		/* offset in list of equal-hashvals */
  	__u16	pad1;		/* padding to match user-level */
  	__u8	pad2;		/* padding to match user-level */
  	__u8	initted;	/* T/F: cursor has been initialized */
  } attrlist_cursor_kern_t;
  
  
  /*========================================================================

   * Structure used to pass context around among the routines.

   *========================================================================*/

  
  typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int,

  			      unsigned char *, int, int, unsigned char *);

  
  typedef struct xfs_attr_list_context {
  	struct xfs_inode		*dp;		/* inode */
  	struct attrlist_cursor_kern	*cursor;	/* position in list */
  	char				*alist;		/* output buffer */
  	int				seen_enough;	/* T/F: seen enough of list? */

  	ssize_t				count;		/* num used entries */

  	int				dupcnt;		/* count dup hashvals seen */
  	int				bufsize;	/* total buffer size */
  	int				firstu;		/* first used byte in buffer */
  	int				flags;		/* from VOP call */
  	int				resynch;	/* T/F: resynch with cursor */
  	int				put_value;	/* T/F: need value for listent */
  	put_listent_func_t		put_listent;	/* list output fmt function */
  	int				index;		/* index into output buffer */
  } xfs_attr_list_context_t;
  
  
  /*========================================================================
   * Function prototypes for the kernel.
   *========================================================================*/

  
  /*
   * Overall external interface routines.
   */

  int xfs_attr_inactive(struct xfs_inode *dp);

  int xfs_attr_rmtval_get(struct xfs_da_args *args);

  int xfs_attr_list_int(struct xfs_attr_list_context *);

  
  #endif	/* __XFS_ATTR_H__ */