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Commit 1fc25f51 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: sanity check ag header values in xrep_calc_ag_resblks 



Check the values we read in from the AG headers when calculating the
block reservations for a repair transaction.  If they're obviously
wrong, substitute worst case assumptions (rather than ENOSPC on a bogus
reservation request).

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarAllison Henderson <allison.henderson@oracle.com>
Reviewed-by: default avatarCarlos Maiolino <cmaiolino@redhat.com>
parent 00d22a1c

fs/xfs/scrub/repair.c

+27 −19
Original line number Diff line number Diff line
@@ -195,8 +195,8 @@ xrep_calc_ag_resblks( 
	struct xfs_scrub_metadata	*sm = sc->sm;

	struct xfs_perag		*pag;

	struct xfs_buf			*bp;

	xfs_agino_t			icount = 0;

	xfs_extlen_t			aglen = 0;

	xfs_agino_t			icount = NULLAGINO;

	xfs_extlen_t			aglen = NULLAGBLOCK;

	xfs_extlen_t			usedlen;

	xfs_extlen_t			freelen;

	xfs_extlen_t			bnobt_sz;
@@ -208,20 +208,14 @@ xrep_calc_ag_resblks( 
	if (!(sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))

		return 0;



	/* Use in-core counters if possible. */

	pag = xfs_perag_get(mp, sm->sm_agno);

	if (pag->pagi_init)

	if (pag->pagi_init) {

		/* Use in-core icount if possible. */

		icount = pag->pagi_count;



	/*

	 * Otherwise try to get the actual counters from disk; if not, make

	 * some worst case assumptions.

	 */

	if (icount == 0) {

		error = xfs_ialloc_read_agi(mp, NULL, sm->sm_agno, &bp);

		if (error) {

			icount = mp->m_sb.sb_agblocks / mp->m_sb.sb_inopblock;

	} else {

		/* Try to get the actual counters from disk. */

		error = xfs_ialloc_read_agi(mp, NULL, sm->sm_agno, &bp);

		if (!error) {

			icount = pag->pagi_count;

			xfs_buf_relse(bp);

		}
@@ -229,18 +223,32 @@ xrep_calc_ag_resblks( 


	/* Now grab the block counters from the AGF. */

	error = xfs_alloc_read_agf(mp, NULL, sm->sm_agno, 0, &bp);

	if (error) {

		aglen = mp->m_sb.sb_agblocks;

		freelen = aglen;

		usedlen = aglen;

	} else {

	if (!error) {

		aglen = be32_to_cpu(XFS_BUF_TO_AGF(bp)->agf_length);

		freelen = pag->pagf_freeblks;

		freelen = be32_to_cpu(XFS_BUF_TO_AGF(bp)->agf_freeblks);

		usedlen = aglen - freelen;

		xfs_buf_relse(bp);

	}

	xfs_perag_put(pag);



	/* If the icount is impossible, make some worst-case assumptions. */

	if (icount == NULLAGINO ||

	    !xfs_verify_agino(mp, sm->sm_agno, icount)) {

		xfs_agino_t	first, last;



		xfs_agino_range(mp, sm->sm_agno, &first, &last);

		icount = last - first + 1;

	}



	/* If the block counts are impossible, make worst-case assumptions. */

	if (aglen == NULLAGBLOCK ||

	    aglen != xfs_ag_block_count(mp, sm->sm_agno) ||

	    freelen >= aglen) {

		aglen = xfs_ag_block_count(mp, sm->sm_agno);

		freelen = aglen;

		usedlen = aglen;

	}



	trace_xrep_calc_ag_resblks(mp, sm->sm_agno, icount, aglen,

			freelen, usedlen);