blob: fa6ea6407992a0315c9fac0851b851af46f416bd [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "xfs_bit.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_bmap.h"
#include "xfs_bmap_btree.h"
#include "xfs_rmap.h"
#include "xfs_rmap_btree.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/btree.h"
/* Set us up with an inode's bmap. */
int
xchk_setup_inode_bmap(
struct xfs_scrub *sc,
struct xfs_inode *ip)
{
int error;
error = xchk_get_inode(sc, ip);
if (error)
goto out;
sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
xfs_ilock(sc->ip, sc->ilock_flags);
/*
* We don't want any ephemeral data fork updates sitting around
* while we inspect block mappings, so wait for directio to finish
* and flush dirty data if we have delalloc reservations.
*/
if (S_ISREG(VFS_I(sc->ip)->i_mode) &&
sc->sm->sm_type == XFS_SCRUB_TYPE_BMBTD) {
inode_dio_wait(VFS_I(sc->ip));
error = filemap_write_and_wait(VFS_I(sc->ip)->i_mapping);
if (error)
goto out;
}
/* Got the inode, lock it and we're ready to go. */
error = xchk_trans_alloc(sc, 0);
if (error)
goto out;
sc->ilock_flags |= XFS_ILOCK_EXCL;
xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
out:
/* scrub teardown will unlock and release the inode */
return error;
}
/*
* Inode fork block mapping (BMBT) scrubber.
* More complex than the others because we have to scrub
* all the extents regardless of whether or not the fork
* is in btree format.
*/
struct xchk_bmap_info {
struct xfs_scrub *sc;
xfs_fileoff_t lastoff;
bool is_rt;
bool is_shared;
bool was_loaded;
int whichfork;
};
/* Look for a corresponding rmap for this irec. */
static inline bool
xchk_bmap_get_rmap(
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec,
xfs_agblock_t agbno,
uint64_t owner,
struct xfs_rmap_irec *rmap)
{
xfs_fileoff_t offset;
unsigned int rflags = 0;
int has_rmap;
int error;
if (info->whichfork == XFS_ATTR_FORK)
rflags |= XFS_RMAP_ATTR_FORK;
/*
* CoW staging extents are owned (on disk) by the refcountbt, so
* their rmaps do not have offsets.
*/
if (info->whichfork == XFS_COW_FORK)
offset = 0;
else
offset = irec->br_startoff;
/*
* If the caller thinks this could be a shared bmbt extent (IOWs,
* any data fork extent of a reflink inode) then we have to use the
* range rmap lookup to make sure we get the correct owner/offset.
*/
if (info->is_shared) {
error = xfs_rmap_lookup_le_range(info->sc->sa.rmap_cur, agbno,
owner, offset, rflags, rmap, &has_rmap);
if (!xchk_should_check_xref(info->sc, &error,
&info->sc->sa.rmap_cur))
return false;
goto out;
}
/*
* Otherwise, use the (faster) regular lookup.
*/
error = xfs_rmap_lookup_le(info->sc->sa.rmap_cur, agbno, 0, owner,
offset, rflags, &has_rmap);
if (!xchk_should_check_xref(info->sc, &error,
&info->sc->sa.rmap_cur))
return false;
if (!has_rmap)
goto out;
error = xfs_rmap_get_rec(info->sc->sa.rmap_cur, rmap, &has_rmap);
if (!xchk_should_check_xref(info->sc, &error,
&info->sc->sa.rmap_cur))
return false;
out:
if (!has_rmap)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
return has_rmap;
}
/* Make sure that we have rmapbt records for this extent. */
STATIC void
xchk_bmap_xref_rmap(
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec,
xfs_agblock_t agbno)
{
struct xfs_rmap_irec rmap;
unsigned long long rmap_end;
uint64_t owner;
if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm))
return;
if (info->whichfork == XFS_COW_FORK)
owner = XFS_RMAP_OWN_COW;
else
owner = info->sc->ip->i_ino;
/* Find the rmap record for this irec. */
if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap))
return;
/* Check the rmap. */
rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount;
if (rmap.rm_startblock > agbno ||
agbno + irec->br_blockcount > rmap_end)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/*
* Check the logical offsets if applicable. CoW staging extents
* don't track logical offsets since the mappings only exist in
* memory.
*/
if (info->whichfork != XFS_COW_FORK) {
rmap_end = (unsigned long long)rmap.rm_offset +
rmap.rm_blockcount;
if (rmap.rm_offset > irec->br_startoff ||
irec->br_startoff + irec->br_blockcount > rmap_end)
xchk_fblock_xref_set_corrupt(info->sc,
info->whichfork, irec->br_startoff);
}
if (rmap.rm_owner != owner)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/*
* Check for discrepancies between the unwritten flag in the irec and
* the rmap. Note that the (in-memory) CoW fork distinguishes between
* unwritten and written extents, but we don't track that in the rmap
* records because the blocks are owned (on-disk) by the refcountbt,
* which doesn't track unwritten state.
*/
if (owner != XFS_RMAP_OWN_COW &&
irec->br_state == XFS_EXT_UNWRITTEN &&
!(rmap.rm_flags & XFS_RMAP_UNWRITTEN))
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (info->whichfork == XFS_ATTR_FORK &&
!(rmap.rm_flags & XFS_RMAP_ATTR_FORK))
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK)
xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
}
/* Cross-reference a single rtdev extent record. */
STATIC void
xchk_bmap_rt_iextent_xref(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
xchk_xref_is_used_rt_space(info->sc, irec->br_startblock,
irec->br_blockcount);
}
/* Cross-reference a single datadev extent record. */
STATIC void
xchk_bmap_iextent_xref(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_mount *mp = info->sc->mp;
xfs_agnumber_t agno;
xfs_agblock_t agbno;
xfs_extlen_t len;
int error;
agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock);
agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
len = irec->br_blockcount;
error = xchk_ag_init(info->sc, agno, &info->sc->sa);
if (!xchk_fblock_process_error(info->sc, info->whichfork,
irec->br_startoff, &error))
return;
xchk_xref_is_used_space(info->sc, agbno, len);
xchk_xref_is_not_inode_chunk(info->sc, agbno, len);
xchk_bmap_xref_rmap(info, irec, agbno);
switch (info->whichfork) {
case XFS_DATA_FORK:
if (xfs_is_reflink_inode(info->sc->ip))
break;
/* fall through */
case XFS_ATTR_FORK:
xchk_xref_is_not_shared(info->sc, agbno,
irec->br_blockcount);
break;
case XFS_COW_FORK:
xchk_xref_is_cow_staging(info->sc, agbno,
irec->br_blockcount);
break;
}
xchk_ag_free(info->sc, &info->sc->sa);
}
/*
* Directories and attr forks should never have blocks that can't be addressed
* by a xfs_dablk_t.
*/
STATIC void
xchk_bmap_dirattr_extent(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_mount *mp = ip->i_mount;
xfs_fileoff_t off;
if (!S_ISDIR(VFS_I(ip)->i_mode) && info->whichfork != XFS_ATTR_FORK)
return;
if (!xfs_verify_dablk(mp, irec->br_startoff))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
off = irec->br_startoff + irec->br_blockcount - 1;
if (!xfs_verify_dablk(mp, off))
xchk_fblock_set_corrupt(info->sc, info->whichfork, off);
}
/* Scrub a single extent record. */
STATIC int
xchk_bmap_iextent(
struct xfs_inode *ip,
struct xchk_bmap_info *info,
struct xfs_bmbt_irec *irec)
{
struct xfs_mount *mp = info->sc->mp;
xfs_filblks_t end;
int error = 0;
/*
* Check for out-of-order extents. This record could have come
* from the incore list, for which there is no ordering check.
*/
if (irec->br_startoff < info->lastoff)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
xchk_bmap_dirattr_extent(ip, info, irec);
/* There should never be a "hole" extent in either extent list. */
if (irec->br_startblock == HOLESTARTBLOCK)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/*
* Check for delalloc extents. We never iterate the ones in the
* in-core extent scan, and we should never see these in the bmbt.
*/
if (isnullstartblock(irec->br_startblock))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/* Make sure the extent points to a valid place. */
if (irec->br_blockcount > MAXEXTLEN)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (irec->br_startblock + irec->br_blockcount <= irec->br_startblock)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
end = irec->br_startblock + irec->br_blockcount - 1;
if (info->is_rt &&
(!xfs_verify_rtbno(mp, irec->br_startblock) ||
!xfs_verify_rtbno(mp, end)))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (!info->is_rt &&
(!xfs_verify_fsbno(mp, irec->br_startblock) ||
!xfs_verify_fsbno(mp, end) ||
XFS_FSB_TO_AGNO(mp, irec->br_startblock) !=
XFS_FSB_TO_AGNO(mp, end)))
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
/* We don't allow unwritten extents on attr forks. */
if (irec->br_state == XFS_EXT_UNWRITTEN &&
info->whichfork == XFS_ATTR_FORK)
xchk_fblock_set_corrupt(info->sc, info->whichfork,
irec->br_startoff);
if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return 0;
if (info->is_rt)
xchk_bmap_rt_iextent_xref(ip, info, irec);
else
xchk_bmap_iextent_xref(ip, info, irec);
info->lastoff = irec->br_startoff + irec->br_blockcount;
return error;
}
/* Scrub a bmbt record. */
STATIC int
xchk_bmapbt_rec(
struct xchk_btree *bs,
union xfs_btree_rec *rec)
{
struct xfs_bmbt_irec irec;
struct xfs_bmbt_irec iext_irec;
struct xfs_iext_cursor icur;
struct xchk_bmap_info *info = bs->private;
struct xfs_inode *ip = bs->cur->bc_private.b.ip;
struct xfs_buf *bp = NULL;
struct xfs_btree_block *block;
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, info->whichfork);
uint64_t owner;
int i;
/*
* Check the owners of the btree blocks up to the level below
* the root since the verifiers don't do that.
*/
if (xfs_sb_version_hascrc(&bs->cur->bc_mp->m_sb) &&
bs->cur->bc_ptrs[0] == 1) {
for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
block = xfs_btree_get_block(bs->cur, i, &bp);
owner = be64_to_cpu(block->bb_u.l.bb_owner);
if (owner != ip->i_ino)
xchk_fblock_set_corrupt(bs->sc,
info->whichfork, 0);
}
}
/*
* Check that the incore extent tree contains an extent that matches
* this one exactly. We validate those cached bmaps later, so we don't
* need to check them here. If the incore extent tree was just loaded
* from disk by the scrubber, we assume that its contents match what's
* on disk (we still hold the ILOCK) and skip the equivalence check.
*/
if (!info->was_loaded)
return 0;
xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur,
&iext_irec) ||
irec.br_startoff != iext_irec.br_startoff ||
irec.br_startblock != iext_irec.br_startblock ||
irec.br_blockcount != iext_irec.br_blockcount ||
irec.br_state != iext_irec.br_state)
xchk_fblock_set_corrupt(bs->sc, info->whichfork,
irec.br_startoff);
return 0;
}
/* Scan the btree records. */
STATIC int
xchk_bmap_btree(
struct xfs_scrub *sc,
int whichfork,
struct xchk_bmap_info *info)
{
struct xfs_owner_info oinfo;
struct xfs_ifork *ifp = XFS_IFORK_PTR(sc->ip, whichfork);
struct xfs_mount *mp = sc->mp;
struct xfs_inode *ip = sc->ip;
struct xfs_btree_cur *cur;
int error;
/* Load the incore bmap cache if it's not loaded. */
info->was_loaded = ifp->if_flags & XFS_IFEXTENTS;
if (!info->was_loaded) {
error = xfs_iread_extents(sc->tp, ip, whichfork);
if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
goto out;
}
/* Check the btree structure. */
cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info);
xfs_btree_del_cursor(cur, error);
out:
return error;
}
struct xchk_bmap_check_rmap_info {
struct xfs_scrub *sc;
int whichfork;
struct xfs_iext_cursor icur;
};
/* Can we find bmaps that fit this rmap? */
STATIC int
xchk_bmap_check_rmap(
struct xfs_btree_cur *cur,
struct xfs_rmap_irec *rec,
void *priv)
{
struct xfs_bmbt_irec irec;
struct xchk_bmap_check_rmap_info *sbcri = priv;
struct xfs_ifork *ifp;
struct xfs_scrub *sc = sbcri->sc;
bool have_map;
/* Is this even the right fork? */
if (rec->rm_owner != sc->ip->i_ino)
return 0;
if ((sbcri->whichfork == XFS_ATTR_FORK) ^
!!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
return 0;
if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
return 0;
/* Now look up the bmbt record. */
ifp = XFS_IFORK_PTR(sc->ip, sbcri->whichfork);
if (!ifp) {
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
goto out;
}
have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
&sbcri->icur, &irec);
if (!have_map)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
/*
* bmap extent record lengths are constrained to 2^21 blocks in length
* because of space constraints in the on-disk metadata structure.
* However, rmap extent record lengths are constrained only by AG
* length, so we have to loop through the bmbt to make sure that the
* entire rmap is covered by bmbt records.
*/
while (have_map) {
if (irec.br_startoff != rec->rm_offset)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
cur->bc_private.a.agno, rec->rm_startblock))
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
if (irec.br_blockcount > rec->rm_blockcount)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
break;
rec->rm_startblock += irec.br_blockcount;
rec->rm_offset += irec.br_blockcount;
rec->rm_blockcount -= irec.br_blockcount;
if (rec->rm_blockcount == 0)
break;
have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
if (!have_map)
xchk_fblock_set_corrupt(sc, sbcri->whichfork,
rec->rm_offset);
}
out:
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return -ECANCELED;
return 0;
}
/* Make sure each rmap has a corresponding bmbt entry. */
STATIC int
xchk_bmap_check_ag_rmaps(
struct xfs_scrub *sc,
int whichfork,
xfs_agnumber_t agno)
{
struct xchk_bmap_check_rmap_info sbcri;
struct xfs_btree_cur *cur;
struct xfs_buf *agf;
int error;
error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf);
if (error)
return error;
cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, agno);
if (!cur) {
error = -ENOMEM;
goto out_agf;
}
sbcri.sc = sc;
sbcri.whichfork = whichfork;
error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri);
if (error == -ECANCELED)
error = 0;
xfs_btree_del_cursor(cur, error);
out_agf:
xfs_trans_brelse(sc->tp, agf);
return error;
}
/* Make sure each rmap has a corresponding bmbt entry. */
STATIC int
xchk_bmap_check_rmaps(
struct xfs_scrub *sc,
int whichfork)
{
loff_t size;
xfs_agnumber_t agno;
int error;
if (!xfs_sb_version_hasrmapbt(&sc->mp->m_sb) ||
whichfork == XFS_COW_FORK ||
(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
return 0;
/* Don't support realtime rmap checks yet. */
if (XFS_IS_REALTIME_INODE(sc->ip) && whichfork == XFS_DATA_FORK)
return 0;
/*
* Only do this for complex maps that are in btree format, or for
* situations where we would seem to have a size but zero extents.
* The inode repair code can zap broken iforks, which means we have
* to flag this bmap as corrupt if there are rmaps that need to be
* reattached.
*/
switch (whichfork) {
case XFS_DATA_FORK:
size = i_size_read(VFS_I(sc->ip));
break;
case XFS_ATTR_FORK:
size = XFS_IFORK_Q(sc->ip);
break;
default:
size = 0;
break;
}
if (XFS_IFORK_FORMAT(sc->ip, whichfork) != XFS_DINODE_FMT_BTREE &&
(size == 0 || XFS_IFORK_NEXTENTS(sc->ip, whichfork) > 0))
return 0;
for (agno = 0; agno < sc->mp->m_sb.sb_agcount; agno++) {
error = xchk_bmap_check_ag_rmaps(sc, whichfork, agno);
if (error)
return error;
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
break;
}
return 0;
}
/*
* Scrub an inode fork's block mappings.
*
* First we scan every record in every btree block, if applicable.
* Then we unconditionally scan the incore extent cache.
*/
STATIC int
xchk_bmap(
struct xfs_scrub *sc,
int whichfork)
{
struct xfs_bmbt_irec irec;
struct xchk_bmap_info info = { NULL };
struct xfs_mount *mp = sc->mp;
struct xfs_inode *ip = sc->ip;
struct xfs_ifork *ifp;
xfs_fileoff_t endoff;
struct xfs_iext_cursor icur;
int error = 0;
ifp = XFS_IFORK_PTR(ip, whichfork);
info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip);
info.whichfork = whichfork;
info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
info.sc = sc;
switch (whichfork) {
case XFS_COW_FORK:
/* Non-existent CoW forks are ignorable. */
if (!ifp)
goto out;
/* No CoW forks on non-reflink inodes/filesystems. */
if (!xfs_is_reflink_inode(ip)) {
xchk_ino_set_corrupt(sc, sc->ip->i_ino);
goto out;
}
break;
case XFS_ATTR_FORK:
if (!ifp)
goto out_check_rmap;
if (!xfs_sb_version_hasattr(&mp->m_sb) &&
!xfs_sb_version_hasattr2(&mp->m_sb))
xchk_ino_set_corrupt(sc, sc->ip->i_ino);
break;
default:
ASSERT(whichfork == XFS_DATA_FORK);
break;
}
/* Check the fork values */
switch (XFS_IFORK_FORMAT(ip, whichfork)) {
case XFS_DINODE_FMT_UUID:
case XFS_DINODE_FMT_DEV:
case XFS_DINODE_FMT_LOCAL:
/* No mappings to check. */
goto out;
case XFS_DINODE_FMT_EXTENTS:
if (!(ifp->if_flags & XFS_IFEXTENTS)) {
xchk_fblock_set_corrupt(sc, whichfork, 0);
goto out;
}
break;
case XFS_DINODE_FMT_BTREE:
if (whichfork == XFS_COW_FORK) {
xchk_fblock_set_corrupt(sc, whichfork, 0);
goto out;
}
error = xchk_bmap_btree(sc, whichfork, &info);
if (error)
goto out;
break;
default:
xchk_fblock_set_corrupt(sc, whichfork, 0);
goto out;
}
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
goto out;
/* Find the offset of the last extent in the mapping. */
error = xfs_bmap_last_offset(ip, &endoff, whichfork);
if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
goto out;
/* Scrub extent records. */
info.lastoff = 0;
ifp = XFS_IFORK_PTR(ip, whichfork);
for_each_xfs_iext(ifp, &icur, &irec) {
if (xchk_should_terminate(sc, &error) ||
(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
goto out;
if (isnullstartblock(irec.br_startblock))
continue;
if (irec.br_startoff >= endoff) {
xchk_fblock_set_corrupt(sc, whichfork,
irec.br_startoff);
goto out;
}
error = xchk_bmap_iextent(ip, &info, &irec);
if (error)
goto out;
}
out_check_rmap:
error = xchk_bmap_check_rmaps(sc, whichfork);
if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error))
goto out;
out:
return error;
}
/* Scrub an inode's data fork. */
int
xchk_bmap_data(
struct xfs_scrub *sc)
{
return xchk_bmap(sc, XFS_DATA_FORK);
}
/* Scrub an inode's attr fork. */
int
xchk_bmap_attr(
struct xfs_scrub *sc)
{
return xchk_bmap(sc, XFS_ATTR_FORK);
}
/* Scrub an inode's CoW fork. */
int
xchk_bmap_cow(
struct xfs_scrub *sc)
{
if (!xfs_is_reflink_inode(sc->ip))
return -ENOENT;
return xchk_bmap(sc, XFS_COW_FORK);
}