Commit 7aab8a05 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

Merge tag 'scrub-fscounters-enhancements-6.2_2022-11-16' of... 

Merge tag 'scrub-fscounters-enhancements-6.2_2022-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux

 into xfs-6.2-mergeA

xfs: enhance fs summary counter scrubber

This series makes two changes to the fs summary counter scrubber: first,
we should mark the scrub incomplete when we can't read the AG headers.
Second, it fixes a functionality gap where we don't actually check the
free rt extent count.

v23.2: fix pointless inline

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>

* tag 'scrub-fscounters-enhancements-6.2_2022-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: online checking of the free rt extent count
  xfs: skip fscounters comparisons when the scan is incomplete
parents b76f593b e74331d6

fs/xfs/scrub/fscounters.c

+104 −3
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 
#include "xfs_health.h"

#include "xfs_btree.h"

#include "xfs_ag.h"

#include "xfs_rtalloc.h"

#include "xfs_inode.h"

#include "scrub/scrub.h"

#include "scrub/common.h"

#include "scrub/trace.h"
@@ -43,6 +45,16 @@ 
 * our tolerance for mismatch between expected and actual counter values.

 */



struct xchk_fscounters {

	struct xfs_scrub	*sc;

	uint64_t		icount;

	uint64_t		ifree;

	uint64_t		fdblocks;

	uint64_t		frextents;

	unsigned long long	icount_min;

	unsigned long long	icount_max;

};



/*

 * Since the expected value computation is lockless but only browses incore

 * values, the percpu counters should be fairly close to each other.  However,
@@ -120,6 +132,7 @@ xchk_setup_fscounters( 
	if (!sc->buf)

		return -ENOMEM;

	fsc = sc->buf;

	fsc->sc = sc;



	xfs_icount_range(sc->mp, &fsc->icount_min, &fsc->icount_max);
@@ -138,6 +151,18 @@ xchk_setup_fscounters( 
	return xchk_trans_alloc(sc, 0);

}



/*

 * Part 1: Collecting filesystem summary counts.  For each AG, we add its

 * summary counts (total inodes, free inodes, free data blocks) to an incore

 * copy of the overall filesystem summary counts.

 *

 * To avoid false corruption reports in part 2, any failure in this part must

 * set the INCOMPLETE flag even when a negative errno is returned.  This care

 * must be taken with certain errno values (i.e. EFSBADCRC, EFSCORRUPTED,

 * ECANCELED) that are absorbed into a scrub state flag update by

 * xchk_*_process_error.

 */



/* Count free space btree blocks manually for pre-lazysbcount filesystems. */

static int

xchk_fscount_btreeblks(
@@ -225,8 +250,10 @@ xchk_fscount_aggregate_agcounts( 
	}

	if (pag)

		xfs_perag_put(pag);

	if (error)

	if (error) {

		xchk_set_incomplete(sc);

		return error;

	}



	/*

	 * The global incore space reservation is taken from the incore
@@ -267,6 +294,64 @@ xchk_fscount_aggregate_agcounts( 
	return 0;

}



#ifdef CONFIG_XFS_RT

STATIC int

xchk_fscount_add_frextent(

	struct xfs_mount		*mp,

	struct xfs_trans		*tp,

	const struct xfs_rtalloc_rec	*rec,

	void				*priv)

{

	struct xchk_fscounters		*fsc = priv;

	int				error = 0;



	fsc->frextents += rec->ar_extcount;



	xchk_should_terminate(fsc->sc, &error);

	return error;

}



/* Calculate the number of free realtime extents from the realtime bitmap. */

STATIC int

xchk_fscount_count_frextents(

	struct xfs_scrub	*sc,

	struct xchk_fscounters	*fsc)

{

	struct xfs_mount	*mp = sc->mp;

	int			error;



	fsc->frextents = 0;

	if (!xfs_has_realtime(mp))

		return 0;



	xfs_ilock(sc->mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);

	error = xfs_rtalloc_query_all(sc->mp, sc->tp,

			xchk_fscount_add_frextent, fsc);

	if (error) {

		xchk_set_incomplete(sc);

		goto out_unlock;

	}



out_unlock:

	xfs_iunlock(sc->mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);

	return error;

}

#else

STATIC int

xchk_fscount_count_frextents(

	struct xfs_scrub	*sc,

	struct xchk_fscounters	*fsc)

{

	fsc->frextents = 0;

	return 0;

}

#endif /* CONFIG_XFS_RT */



/*

 * Part 2: Comparing filesystem summary counters.  All we have to do here is

 * sum the percpu counters and compare them to what we've observed.

 */



/*

 * Is the @counter reasonably close to the @expected value?

 *
@@ -333,16 +418,17 @@ xchk_fscounters( 
{

	struct xfs_mount	*mp = sc->mp;

	struct xchk_fscounters	*fsc = sc->buf;

	int64_t			icount, ifree, fdblocks;

	int64_t			icount, ifree, fdblocks, frextents;

	int			error;



	/* Snapshot the percpu counters. */

	icount = percpu_counter_sum(&mp->m_icount);

	ifree = percpu_counter_sum(&mp->m_ifree);

	fdblocks = percpu_counter_sum(&mp->m_fdblocks);

	frextents = percpu_counter_sum(&mp->m_frextents);



	/* No negative values, please! */

	if (icount < 0 || ifree < 0 || fdblocks < 0)

	if (icount < 0 || ifree < 0 || fdblocks < 0 || frextents < 0)

		xchk_set_corrupt(sc);



	/* See if icount is obviously wrong. */
@@ -353,6 +439,10 @@ xchk_fscounters( 
	if (fdblocks > mp->m_sb.sb_dblocks)

		xchk_set_corrupt(sc);



	/* See if frextents is obviously wrong. */

	if (frextents > mp->m_sb.sb_rextents)

		xchk_set_corrupt(sc);



	/*

	 * If ifree exceeds icount by more than the minimum variance then

	 * something's probably wrong with the counters.
@@ -367,6 +457,13 @@ xchk_fscounters( 
	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_INCOMPLETE)

		return 0;



	/* Count the free extents counter for rt volumes. */

	error = xchk_fscount_count_frextents(sc, fsc);

	if (!xchk_process_error(sc, 0, XFS_SB_BLOCK(mp), &error))

		return error;

	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_INCOMPLETE)

		return 0;



	/* Compare the in-core counters with whatever we counted. */

	if (!xchk_fscount_within_range(sc, icount, &mp->m_icount, fsc->icount))

		xchk_set_corrupt(sc);
@@ -378,5 +475,9 @@ xchk_fscounters( 
			fsc->fdblocks))

		xchk_set_corrupt(sc);



	if (!xchk_fscount_within_range(sc, frextents, &mp->m_frextents,

			fsc->frextents))

		xchk_set_corrupt(sc);



	return 0;

}

fs/xfs/scrub/scrub.h

+0 −8
Original line number Diff line number Diff line
@@ -169,12 +169,4 @@ void xchk_xref_is_used_rt_space(struct xfs_scrub *sc, xfs_rtblock_t rtbno, 
# define xchk_xref_is_used_rt_space(sc, rtbno, len) do { } while (0)

#endif



struct xchk_fscounters {

	uint64_t		icount;

	uint64_t		ifree;

	uint64_t		fdblocks;

	unsigned long long	icount_min;

	unsigned long long	icount_max;

};



#endif	/* __XFS_SCRUB_SCRUB_H__ */