text: /* SPDX-License-Identifier: GPL-2.0-or-later */
  /*
   * Copyright (C) 2019 Oracle.  All Rights Reserved.
   * Author: Darrick J. Wong <darrick.wong@oracle.com>
   */
  #ifndef __XFS_SCRUB_ATTR_H__
  #define __XFS_SCRUB_ATTR_H__
  
  /*
   * Temporary storage for online scrub and repair of extended attributes.
   */
  struct xchk_xattr_buf {
  	/* Size of @buf, in bytes. */
  	size_t			sz;
  
  	/*
  	 * Memory buffer -- either used for extracting attr values while
  	 * walking the attributes; or for computing attr block bitmaps when
  	 * checking the attribute tree.
  	 *
  	 * Each bitmap contains enough bits to track every byte in an attr
  	 * block (rounded up to the size of an unsigned long).  The attr block
  	 * used space bitmap starts at the beginning of the buffer; the free
  	 * space bitmap follows immediately after; and we have a third buffer
  	 * for storing intermediate bitmap results.
  	 */
  	uint8_t			buf[];
  };
  
  /* A place to store attribute values. */
  static inline uint8_t *
  xchk_xattr_valuebuf(
  	struct xfs_scrub	*sc)
  {
  	struct xchk_xattr_buf	*ab = sc->buf;
  
  	return ab->buf;
  }
  
  /* A bitmap of space usage computed by walking an attr leaf block. */
  static inline unsigned long *
  xchk_xattr_usedmap(
  	struct xfs_scrub	*sc)
  {
  	struct xchk_xattr_buf	*ab = sc->buf;
  
  	return (unsigned long *)ab->buf;
  }
  
  /* A bitmap of free space computed by walking attr leaf block free info. */
  static inline unsigned long *
  xchk_xattr_freemap(
  	struct xfs_scrub	*sc)
  {
  	return xchk_xattr_usedmap(sc) +
  			BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
  }
  
  /* A bitmap used to hold temporary results. */
  static inline unsigned long *
  xchk_xattr_dstmap(
  	struct xfs_scrub	*sc)
  {
  	return xchk_xattr_freemap(sc) +
  			BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
  }
  
  #endif	/* __XFS_SCRUB_ATTR_H__ */
  