Commit b65e08f8 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: create a predicate to verify per-AG extents 



Create a predicate function to verify that a given agbno/blockcount pair
fit entirely within a single allocation group and don't suffer
mathematical overflows.  Refactor the existng open-coded logic; we're
going to add more calls to this function in the next patch.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent f850995f

fs/xfs/libxfs/xfs_ag.h

+15 −0
Original line number Diff line number Diff line
@@ -133,6 +133,21 @@ xfs_verify_agbno(struct xfs_perag *pag, xfs_agblock_t agbno) 
	return true;

}



static inline bool

xfs_verify_agbext(

	struct xfs_perag	*pag,

	xfs_agblock_t		agbno,

	xfs_agblock_t		len)

{

	if (agbno + len <= agbno)

		return false;



	if (!xfs_verify_agbno(pag, agbno))

		return false;



	return xfs_verify_agbno(pag, agbno + len - 1);

}



/*

 * Verify that an AG inode number pointer neither points outside the AG

 * nor points at static metadata.

fs/xfs/libxfs/xfs_alloc.c

+1 −5
Original line number Diff line number Diff line
@@ -263,11 +263,7 @@ xfs_alloc_get_rec( 
		goto out_bad_rec;



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

	if (!xfs_verify_agbno(pag, *bno))

		goto out_bad_rec;

	if (*bno > *bno + *len)

		goto out_bad_rec;

	if (!xfs_verify_agbno(pag, *bno + *len - 1))

	if (!xfs_verify_agbext(pag, *bno, *len))

		goto out_bad_rec;



	return 0;

fs/xfs/libxfs/xfs_refcount.c

+1 −5
Original line number Diff line number Diff line
@@ -135,11 +135,7 @@ xfs_refcount_get_rec( 
	}



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

	if (!xfs_verify_agbno(pag, realstart))

		goto out_bad_rec;

	if (realstart > realstart + irec->rc_blockcount)

		goto out_bad_rec;

	if (!xfs_verify_agbno(pag, realstart + irec->rc_blockcount - 1))

	if (!xfs_verify_agbext(pag, realstart, irec->rc_blockcount))

		goto out_bad_rec;



	if (irec->rc_refcount == 0 || irec->rc_refcount > MAXREFCOUNT)

fs/xfs/libxfs/xfs_rmap.c

+2 −7
Original line number Diff line number Diff line
@@ -235,13 +235,8 @@ xfs_rmap_get_rec( 
			goto out_bad_rec;

	} else {

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

		if (!xfs_verify_agbno(pag, irec->rm_startblock))

			goto out_bad_rec;

		if (irec->rm_startblock >

				irec->rm_startblock + irec->rm_blockcount)

			goto out_bad_rec;

		if (!xfs_verify_agbno(pag,

				irec->rm_startblock + irec->rm_blockcount - 1))

		if (!xfs_verify_agbext(pag, irec->rm_startblock,

					    irec->rm_blockcount))

			goto out_bad_rec;

	}

fs/xfs/scrub/alloc.c

+1 −3
Original line number Diff line number Diff line
@@ -100,9 +100,7 @@ xchk_allocbt_rec( 
	bno = be32_to_cpu(rec->alloc.ar_startblock);

	len = be32_to_cpu(rec->alloc.ar_blockcount);



	if (bno + len <= bno ||

	    !xfs_verify_agbno(pag, bno) ||

	    !xfs_verify_agbno(pag, bno + len - 1))

	if (!xfs_verify_agbext(pag, bno, len))

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



	xchk_allocbt_xref(bs->sc, bno, len);