fs/xfs/scrub/health.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_btree.h"
  11 #include "xfs_sb.h"
  12 #include "xfs_health.h"
  13 #include "scrub/scrub.h"
  14 #include "scrub/health.h"
  15
  16 /*
  17  * Scrub and In-Core Filesystem Health Assessments
  18  * ===============================================
  19  *
  20  * Online scrub and repair have the time and the ability to perform stronger
  21  * checks than we can do from the metadata verifiers, because they can
  22  * cross-reference records between data structures.  Therefore, scrub is in a
  23  * good position to update the online filesystem health assessments to reflect
  24  * the good/bad state of the data structure.
  25  *
  26  * We therefore extend scrub in the following ways to achieve this:
  27  *
  28  * 1. Create a "sick_mask" field in the scrub context.  When we're setting up a
  29  * scrub call, set this to the default XFS_SICK_* flag(s) for the selected
  30  * scrub type (call it A).  Scrub and repair functions can override the default
  31  * sick_mask value if they choose.
  32  *
  33  * 2. If the scrubber returns a runtime error code, we exit making no changes
  34  * to the incore sick state.
  35  *
  36  * 3. If the scrubber finds that A is clean, use sick_mask to clear the incore
  37  * sick flags before exiting.
  38  *
  39  * 4. If the scrubber finds that A is corrupt, use sick_mask to set the incore
  40  * sick flags.  If the user didn't want to repair then we exit, leaving the
  41  * metadata structure unfixed and the sick flag set.
  42  *
  43  * 5. Now we know that A is corrupt and the user wants to repair, so run the
  44  * repairer.  If the repairer returns an error code, we exit with that error
  45  * code, having made no further changes to the incore sick state.
  46  *
  47  * 6. If repair rebuilds A correctly and the subsequent re-scrub of A is clean,
  48  * use sick_mask to clear the incore sick flags.  This should have the effect
  49  * that A is no longer marked sick.
  50  *
  51  * 7. If repair rebuilds A incorrectly, the re-scrub will find it corrupt and
  52  * use sick_mask to set the incore sick flags.  This should have no externally
  53  * visible effect since we already set them in step (4).
  54  *
  55  * There are some complications to this story, however.  For certain types of
  56  * complementary metadata indices (e.g. inobt/finobt), it is easier to rebuild
  57  * both structures at the same time.  The following principles apply to this
  58  * type of repair strategy:
  59  *
  60  * 8. Any repair function that rebuilds multiple structures should update
  61  * sick_mask_visible to reflect whatever other structures are rebuilt, and
  62  * verify that all the rebuilt structures can pass a scrub check.  The outcomes
  63  * of 5-7 still apply, but with a sick_mask that covers everything being
  64  * rebuilt.
  65  */
  66
  67 /* Map our scrub type to a sick mask and a set of health update functions. */
  68
  69 enum xchk_health_group {
  70         XHG_FS = 1,
  71         XHG_RT,
  72         XHG_AG,
  73         XHG_INO,
  74 };
  75
  76 struct xchk_health_map {
  77         enum xchk_health_group  group;
  78         unsigned int            sick_mask;
  79 };
  80
  81 static const struct xchk_health_map type_to_health_flag[XFS_SCRUB_TYPE_NR] = {
  82         [XFS_SCRUB_TYPE_SB]             = { XHG_AG,  XFS_SICK_AG_SB },
  83         [XFS_SCRUB_TYPE_AGF]            = { XHG_AG,  XFS_SICK_AG_AGF },
  84         [XFS_SCRUB_TYPE_AGFL]           = { XHG_AG,  XFS_SICK_AG_AGFL },
  85         [XFS_SCRUB_TYPE_AGI]            = { XHG_AG,  XFS_SICK_AG_AGI },
  86         [XFS_SCRUB_TYPE_BNOBT]          = { XHG_AG,  XFS_SICK_AG_BNOBT },
  87         [XFS_SCRUB_TYPE_CNTBT]          = { XHG_AG,  XFS_SICK_AG_CNTBT },
  88         [XFS_SCRUB_TYPE_INOBT]          = { XHG_AG,  XFS_SICK_AG_INOBT },
  89         [XFS_SCRUB_TYPE_FINOBT]         = { XHG_AG,  XFS_SICK_AG_FINOBT },
  90         [XFS_SCRUB_TYPE_RMAPBT]         = { XHG_AG,  XFS_SICK_AG_RMAPBT },
  91         [XFS_SCRUB_TYPE_REFCNTBT]       = { XHG_AG,  XFS_SICK_AG_REFCNTBT },
  92         [XFS_SCRUB_TYPE_INODE]          = { XHG_INO, XFS_SICK_INO_CORE },
  93         [XFS_SCRUB_TYPE_BMBTD]          = { XHG_INO, XFS_SICK_INO_BMBTD },
  94         [XFS_SCRUB_TYPE_BMBTA]          = { XHG_INO, XFS_SICK_INO_BMBTA },
  95         [XFS_SCRUB_TYPE_BMBTC]          = { XHG_INO, XFS_SICK_INO_BMBTC },
  96         [XFS_SCRUB_TYPE_DIR]            = { XHG_INO, XFS_SICK_INO_DIR },
  97         [XFS_SCRUB_TYPE_XATTR]          = { XHG_INO, XFS_SICK_INO_XATTR },
  98         [XFS_SCRUB_TYPE_SYMLINK]        = { XHG_INO, XFS_SICK_INO_SYMLINK },
  99         [XFS_SCRUB_TYPE_PARENT]         = { XHG_INO, XFS_SICK_INO_PARENT },
 100         [XFS_SCRUB_TYPE_RTBITMAP]       = { XHG_RT,  XFS_SICK_RT_BITMAP },
 101         [XFS_SCRUB_TYPE_RTSUM]          = { XHG_RT,  XFS_SICK_RT_SUMMARY },
 102         [XFS_SCRUB_TYPE_UQUOTA]         = { XHG_FS,  XFS_SICK_FS_UQUOTA },
 103         [XFS_SCRUB_TYPE_GQUOTA]         = { XHG_FS,  XFS_SICK_FS_GQUOTA },
 104         [XFS_SCRUB_TYPE_PQUOTA]         = { XHG_FS,  XFS_SICK_FS_PQUOTA },
 105         [XFS_SCRUB_TYPE_FSCOUNTERS]     = { XHG_FS,  XFS_SICK_FS_COUNTERS },
 106 };
 107
 108 /* Return the health status mask for this scrub type. */
 109 unsigned int
 110 xchk_health_mask_for_scrub_type(
 111         __u32                   scrub_type)
 112 {
 113         return type_to_health_flag[scrub_type].sick_mask;
 114 }
 115
 116 /*
 117  * Update filesystem health assessments based on what we found and did.
 118  *
 119  * If the scrubber finds errors, we mark sick whatever's mentioned in
 120  * sick_mask, no matter whether this is a first scan or an
 121  * evaluation of repair effectiveness.
 122  *
 123  * Otherwise, no direct corruption was found, so mark whatever's in
 124  * sick_mask as healthy.
 125  */
 126 void
 127 xchk_update_health(
 128         struct xfs_scrub        *sc)
 129 {
 130         struct xfs_perag        *pag;
 131         bool                    bad;
 132
 133         if (!sc->sick_mask)
 134                 return;
 135
 136         bad = (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT);
 137         switch (type_to_health_flag[sc->sm->sm_type].group) {
 138         case XHG_AG:
 139                 pag = xfs_perag_get(sc->mp, sc->sm->sm_agno);
 140                 if (bad)
 141                         xfs_ag_mark_sick(pag, sc->sick_mask);
 142                 else
 143                         xfs_ag_mark_healthy(pag, sc->sick_mask);
 144                 xfs_perag_put(pag);
 145                 break;
 146         case XHG_INO:
 147                 if (!sc->ip)
 148                         return;
 149                 if (bad)
 150                         xfs_inode_mark_sick(sc->ip, sc->sick_mask);
 151                 else
 152                         xfs_inode_mark_healthy(sc->ip, sc->sick_mask);
 153                 break;
 154         case XHG_FS:
 155                 if (bad)
 156                         xfs_fs_mark_sick(sc->mp, sc->sick_mask);
 157                 else
 158                         xfs_fs_mark_healthy(sc->mp, sc->sick_mask);
 159                 break;
 160         case XHG_RT:
 161                 if (bad)
 162                         xfs_rt_mark_sick(sc->mp, sc->sick_mask);
 163                 else
 164                         xfs_rt_mark_healthy(sc->mp, sc->sick_mask);
 165                 break;
 166         default:
 167                 ASSERT(0);
 168                 break;
 169         }
 170 }
 171
 172 /* Is the given per-AG btree healthy enough for scanning? */
 173 bool
 174 xchk_ag_btree_healthy_enough(
 175         struct xfs_scrub        *sc,
 176         struct xfs_perag        *pag,
 177         xfs_btnum_t             btnum)
 178 {
 179         unsigned int            mask = 0;
 180
 181         /*
 182          * We always want the cursor if it's the same type as whatever we're
 183          * scrubbing, even if we already know the structure is corrupt.
 184          *
 185          * Otherwise, we're only interested in the btree for cross-referencing.
 186          * If we know the btree is bad then don't bother, just set XFAIL.
 187          */
 188         switch (btnum) {
 189         case XFS_BTNUM_BNO:
 190                 if (sc->sm->sm_type == XFS_SCRUB_TYPE_BNOBT)
 191                         return true;
 192                 mask = XFS_SICK_AG_BNOBT;
 193                 break;
 194         case XFS_BTNUM_CNT:
 195                 if (sc->sm->sm_type == XFS_SCRUB_TYPE_CNTBT)
 196                         return true;
 197                 mask = XFS_SICK_AG_CNTBT;
 198                 break;
 199         case XFS_BTNUM_INO:
 200                 if (sc->sm->sm_type == XFS_SCRUB_TYPE_INOBT)
 201                         return true;
 202                 mask = XFS_SICK_AG_INOBT;
 203                 break;
 204         case XFS_BTNUM_FINO:
 205                 if (sc->sm->sm_type == XFS_SCRUB_TYPE_FINOBT)
 206                         return true;
 207                 mask = XFS_SICK_AG_FINOBT;
 208                 break;
 209         case XFS_BTNUM_RMAP:
 210                 if (sc->sm->sm_type == XFS_SCRUB_TYPE_RMAPBT)
 211                         return true;
 212                 mask = XFS_SICK_AG_RMAPBT;
 213                 break;
 214         case XFS_BTNUM_REFC:
 215                 if (sc->sm->sm_type == XFS_SCRUB_TYPE_REFCNTBT)
 216                         return true;
 217                 mask = XFS_SICK_AG_REFCNTBT;
 218                 break;
 219         default:
 220                 ASSERT(0);
 221                 return true;
 222         }
 223
 224         if (xfs_ag_has_sickness(pag, mask)) {
 225                 sc->sm->sm_flags |= XFS_SCRUB_OFLAG_XFAIL;
 226                 return false;
 227         }
 228
 229         return true;
 230 }