Commit f492135d authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: refactor domain and refcount checking 



Create a helper function to ensure that CoW staging extent records have
a single refcount and that shared extent records have more than 1
refcount.  We'll put this to more use in the next patch.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent 571423a1

fs/xfs/libxfs/xfs_refcount.c

+1 −4
Original line number Diff line number Diff line
@@ -142,10 +142,7 @@ xfs_refcount_get_rec( 
	if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN)

		goto out_bad_rec;



	/* handle special COW-staging domain */

	if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)

		goto out_bad_rec;

	if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)

	if (!xfs_refcount_check_domain(irec))

		goto out_bad_rec;



	/* check for valid extent range, including overflow */

fs/xfs/libxfs/xfs_refcount.h

+12 −0
Original line number Diff line number Diff line
@@ -55,6 +55,18 @@ struct xfs_refcount_intent { 
	xfs_fsblock_t				ri_startblock;

};



/* Check that the refcount is appropriate for the record domain. */

static inline bool

xfs_refcount_check_domain(

	const struct xfs_refcount_irec	*irec)

{

	if (irec->rc_domain == XFS_REFC_DOMAIN_COW && irec->rc_refcount != 1)

		return false;

	if (irec->rc_domain == XFS_REFC_DOMAIN_SHARED && irec->rc_refcount < 2)

		return false;

	return true;

}



void xfs_refcount_increase_extent(struct xfs_trans *tp,

		struct xfs_bmbt_irec *irec);

void xfs_refcount_decrease_extent(struct xfs_trans *tp,

fs/xfs/scrub/refcount.c

+4 −6
Original line number Diff line number Diff line
@@ -337,14 +337,12 @@ xchk_refcountbt_rec( 


	xfs_refcount_btrec_to_irec(rec, &irec);



	/* Only CoW records can have refcount == 1. */

	if (irec.rc_domain == XFS_REFC_DOMAIN_SHARED && irec.rc_refcount == 1)

		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);

	if (irec.rc_domain == XFS_REFC_DOMAIN_COW) {

		if (irec.rc_refcount != 1)

	/* Check the domain and refcount are not incompatible. */

	if (!xfs_refcount_check_domain(&irec))

		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);



	if (irec.rc_domain == XFS_REFC_DOMAIN_COW)

		(*cow_blocks) += irec.rc_blockcount;

	}



	/* Check the extent. */

	if (!xfs_verify_agbext(pag, irec.rc_startblock, irec.rc_blockcount))