Commit fed050f3 authored by Darrick J. Wong's avatar Darrick J. Wong

xfs: cross-reference rmap records with ag btrees

Strengthen the rmap btree record checker a little more by comparing
OWN_FS and OWN_LOG reverse mappings against the AG headers and internal
logs, respectively.
Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent a47bd1e0
......@@ -148,6 +148,7 @@ xfs-y += $(addprefix scrub/, \
agheader.o \
alloc.o \
attr.o \
bitmap.o \
bmap.o \
btree.o \
common.o \
......@@ -172,7 +173,6 @@ xfs-$(CONFIG_XFS_QUOTA) += scrub/quota.o
ifeq ($(CONFIG_XFS_ONLINE_REPAIR),y)
xfs-y += $(addprefix scrub/, \
agheader_repair.o \
bitmap.o \
repair.o \
)
endif
......
......@@ -396,3 +396,25 @@ xbitmap_empty(
{
return bitmap->xb_root.rb_root.rb_node == NULL;
}
/* Is the start of the range set or clear? And for how long? */
bool
xbitmap_test(
struct xbitmap *bitmap,
uint64_t start,
uint64_t *len)
{
struct xbitmap_node *bn;
uint64_t last = start + *len - 1;
bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
if (!bn)
return false;
if (bn->bn_start <= start) {
if (bn->bn_last < last)
*len = bn->bn_last - start + 1;
return true;
}
*len = bn->bn_start - start;
return false;
}
......@@ -38,6 +38,7 @@ int xbitmap_walk_bits(struct xbitmap *bitmap, xbitmap_walk_bits_fn fn,
void *priv);
bool xbitmap_empty(struct xbitmap *bitmap);
bool xbitmap_test(struct xbitmap *bitmap, uint64_t start, uint64_t *len);
/* Bitmaps, but for type-checked for xfs_agblock_t */
......@@ -66,6 +67,26 @@ static inline int xagb_bitmap_set(struct xagb_bitmap *bitmap,
return xbitmap_set(&bitmap->agbitmap, start, len);
}
static inline bool
xagb_bitmap_test(
struct xagb_bitmap *bitmap,
xfs_agblock_t start,
xfs_extlen_t *len)
{
uint64_t biglen = *len;
bool ret;
ret = xbitmap_test(&bitmap->agbitmap, start, &biglen);
if (start + biglen >= UINT_MAX) {
ASSERT(0);
biglen = UINT_MAX - start;
}
*len = biglen;
return ret;
}
static inline int xagb_bitmap_disunion(struct xagb_bitmap *bitmap,
struct xagb_bitmap *sub)
{
......
......@@ -12,10 +12,12 @@
#include "xfs_btree.h"
#include "xfs_rmap.h"
#include "xfs_refcount.h"
#include "xfs_ag.h"
#include "xfs_bit.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/btree.h"
#include "xfs_ag.h"
#include "scrub/bitmap.h"
/*
* Set us up to scrub reverse mapping btrees.
......@@ -45,6 +47,13 @@ struct xchk_rmap {
* that could be one.
*/
struct xfs_rmap_irec prev_rec;
/* Bitmaps containing all blocks for each type of AG metadata. */
struct xagb_bitmap fs_owned;
struct xagb_bitmap log_owned;
/* Did we complete the AG space metadata bitmaps? */
bool bitmaps_complete;
};
/* Cross-reference a rmap against the refcount btree. */
......@@ -249,6 +258,68 @@ xchk_rmapbt_check_mergeable(
memcpy(&cr->prev_rec, irec, sizeof(struct xfs_rmap_irec));
}
/* Compare an rmap for AG metadata against the metadata walk. */
STATIC int
xchk_rmapbt_mark_bitmap(
struct xchk_btree *bs,
struct xchk_rmap *cr,
const struct xfs_rmap_irec *irec)
{
struct xfs_scrub *sc = bs->sc;
struct xagb_bitmap *bmp = NULL;
xfs_extlen_t fsbcount = irec->rm_blockcount;
/*
* Skip corrupt records. It is essential that we detect records in the
* btree that cannot overlap but do, flag those as CORRUPT, and skip
* the bitmap comparison to avoid generating false XCORRUPT reports.
*/
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return 0;
/*
* If the AG metadata walk didn't complete, there's no point in
* comparing against partial results.
*/
if (!cr->bitmaps_complete)
return 0;
switch (irec->rm_owner) {
case XFS_RMAP_OWN_FS:
bmp = &cr->fs_owned;
break;
case XFS_RMAP_OWN_LOG:
bmp = &cr->log_owned;
break;
}
if (!bmp)
return 0;
if (xagb_bitmap_test(bmp, irec->rm_startblock, &fsbcount)) {
/*
* The start of this reverse mapping corresponds to a set
* region in the bitmap. If the mapping covers more area than
* the set region, then it covers space that wasn't found by
* the AG metadata walk.
*/
if (fsbcount < irec->rm_blockcount)
xchk_btree_xref_set_corrupt(bs->sc,
bs->sc->sa.rmap_cur, 0);
} else {
/*
* The start of this reverse mapping does not correspond to a
* completely set region in the bitmap. The region wasn't
* fully set by walking the AG metadata, so this is a
* cross-referencing corruption.
*/
xchk_btree_xref_set_corrupt(bs->sc, bs->sc->sa.rmap_cur, 0);
}
/* Unset the region so that we can detect missing rmap records. */
return xagb_bitmap_clear(bmp, irec->rm_startblock, irec->rm_blockcount);
}
/* Scrub an rmapbt record. */
STATIC int
xchk_rmapbt_rec(
......@@ -268,9 +339,80 @@ xchk_rmapbt_rec(
xchk_rmapbt_check_mergeable(bs, cr, &irec);
xchk_rmapbt_check_overlapping(bs, cr, &irec);
xchk_rmapbt_xref(bs->sc, &irec);
return xchk_rmapbt_mark_bitmap(bs, cr, &irec);
}
/*
* Set up bitmaps mapping all the AG metadata to compare with the rmapbt
* records.
*/
STATIC int
xchk_rmapbt_walk_ag_metadata(
struct xfs_scrub *sc,
struct xchk_rmap *cr)
{
struct xfs_mount *mp = sc->mp;
int error;
/* OWN_FS: AG headers */
error = xagb_bitmap_set(&cr->fs_owned, XFS_SB_BLOCK(mp),
XFS_AGFL_BLOCK(mp) - XFS_SB_BLOCK(mp) + 1);
if (error)
goto out;
/* OWN_LOG: Internal log */
if (xfs_ag_contains_log(mp, sc->sa.pag->pag_agno)) {
error = xagb_bitmap_set(&cr->log_owned,
XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart),
mp->m_sb.sb_logblocks);
if (error)
goto out;
}
out:
/*
* If there's an error, set XFAIL and disable the bitmap
* cross-referencing checks, but proceed with the scrub anyway.
*/
if (error)
xchk_btree_xref_process_error(sc, sc->sa.rmap_cur,
sc->sa.rmap_cur->bc_nlevels - 1, &error);
else
cr->bitmaps_complete = true;
return 0;
}
/*
* Check for set regions in the bitmaps; if there are any, the rmap records do
* not describe all the AG metadata.
*/
STATIC void
xchk_rmapbt_check_bitmaps(
struct xfs_scrub *sc,
struct xchk_rmap *cr)
{
struct xfs_btree_cur *cur = sc->sa.rmap_cur;
unsigned int level;
if (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
XFS_SCRUB_OFLAG_XFAIL))
return;
if (!cur)
return;
level = cur->bc_nlevels - 1;
/*
* Any bitmap with bits still set indicates that the reverse mapping
* doesn't cover the entire primary structure.
*/
if (xagb_bitmap_hweight(&cr->fs_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
if (xagb_bitmap_hweight(&cr->log_owned) != 0)
xchk_btree_xref_set_corrupt(sc, cur, level);
}
/* Scrub the rmap btree for some AG. */
int
xchk_rmapbt(
......@@ -283,8 +425,23 @@ xchk_rmapbt(
if (!cr)
return -ENOMEM;
xagb_bitmap_init(&cr->fs_owned);
xagb_bitmap_init(&cr->log_owned);
error = xchk_rmapbt_walk_ag_metadata(sc, cr);
if (error)
goto out;
error = xchk_btree(sc, sc->sa.rmap_cur, xchk_rmapbt_rec,
&XFS_RMAP_OINFO_AG, cr);
if (error)
goto out;
xchk_rmapbt_check_bitmaps(sc, cr);
out:
xagb_bitmap_destroy(&cr->log_owned);
xagb_bitmap_destroy(&cr->fs_owned);
kfree(cr);
return error;
}
......
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