fs/xfs/scrub/attr.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Copyright (C) 2019 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5  */
   6 #ifndef __XFS_SCRUB_ATTR_H__
   7 #define __XFS_SCRUB_ATTR_H__
   8
   9 /*
  10  * Temporary storage for online scrub and repair of extended attributes.
  11  */
  12 struct xchk_xattr_buf {
  13         /* Size of @buf, in bytes. */
  14         size_t                  sz;
  15
  16         /*
  17          * Memory buffer -- either used for extracting attr values while
  18          * walking the attributes; or for computing attr block bitmaps when
  19          * checking the attribute tree.
  20          *
  21          * Each bitmap contains enough bits to track every byte in an attr
  22          * block (rounded up to the size of an unsigned long).  The attr block
  23          * used space bitmap starts at the beginning of the buffer; the free
  24          * space bitmap follows immediately after; and we have a third buffer
  25          * for storing intermediate bitmap results.
  26          */
  27         uint8_t                 buf[0];
  28 };
  29
  30 /* A place to store attribute values. */
  31 static inline uint8_t *
  32 xchk_xattr_valuebuf(
  33         struct xfs_scrub        *sc)
  34 {
  35         struct xchk_xattr_buf   *ab = sc->buf;
  36
  37         return ab->buf;
  38 }
  39
  40 /* A bitmap of space usage computed by walking an attr leaf block. */
  41 static inline unsigned long *
  42 xchk_xattr_usedmap(
  43         struct xfs_scrub        *sc)
  44 {
  45         struct xchk_xattr_buf   *ab = sc->buf;
  46
  47         return (unsigned long *)ab->buf;
  48 }
  49
  50 /* A bitmap of free space computed by walking attr leaf block free info. */
  51 static inline unsigned long *
  52 xchk_xattr_freemap(
  53         struct xfs_scrub        *sc)
  54 {
  55         return xchk_xattr_usedmap(sc) +
  56                         BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
  57 }
  58
  59 /* A bitmap used to hold temporary results. */
  60 static inline unsigned long *
  61 xchk_xattr_dstmap(
  62         struct xfs_scrub        *sc)
  63 {
  64         return xchk_xattr_freemap(sc) +
  65                         BITS_TO_LONGS(sc->mp->m_attr_geo->blksize);
  66 }
  67
  68 int xchk_setup_xattr_buf(struct xfs_scrub *sc, size_t value_size,
  69                 xfs_km_flags_t flags);
  70
  71 #endif  /* __XFS_SCRUB_ATTR_H__ */