Commit 35e3b9a1 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: standardize ondisk to incore conversion for free space btrees 



Create a xfs_alloc_btrec_to_irec function to convert an ondisk record to
an incore record, and a xfs_alloc_check_irec function to detect
corruption.  Replace all the open-coded logic with calls to the new
helpers and bubble up corruption reports.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent 88accf17

fs/xfs/libxfs/xfs_alloc.c

+43 −13
Original line number Diff line number Diff line
@@ -233,6 +233,34 @@ xfs_alloc_update( 
	return xfs_btree_update(cur, &rec);

}



/* Convert the ondisk btree record to its incore representation. */

void

xfs_alloc_btrec_to_irec(

	const union xfs_btree_rec	*rec,

	struct xfs_alloc_rec_incore	*irec)

{

	irec->ar_startblock = be32_to_cpu(rec->alloc.ar_startblock);

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

}



/* Simple checks for free space records. */

xfs_failaddr_t

xfs_alloc_check_irec(

	struct xfs_btree_cur		*cur,

	const struct xfs_alloc_rec_incore *irec)

{

	struct xfs_perag		*pag = cur->bc_ag.pag;



	if (irec->ar_blockcount == 0)

		return __this_address;



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

	if (!xfs_verify_agbext(pag, irec->ar_startblock, irec->ar_blockcount))

		return __this_address;



	return NULL;

}



/*

 * Get the data from the pointed-to record.

 */
@@ -243,34 +271,34 @@ xfs_alloc_get_rec( 
	xfs_extlen_t		*len,	/* output: length of extent */

	int			*stat)	/* output: success/failure */

{

	struct xfs_alloc_rec_incore irec;

	struct xfs_mount	*mp = cur->bc_mp;

	struct xfs_perag	*pag = cur->bc_ag.pag;

	union xfs_btree_rec	*rec;

	xfs_failaddr_t		fa;

	int			error;



	error = xfs_btree_get_rec(cur, &rec, stat);

	if (error || !(*stat))

		return error;



	*bno = be32_to_cpu(rec->alloc.ar_startblock);

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



	if (*len == 0)

		goto out_bad_rec;



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

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

	xfs_alloc_btrec_to_irec(rec, &irec);

	fa = xfs_alloc_check_irec(cur, &irec);

	if (fa)

		goto out_bad_rec;



	*bno = irec.ar_startblock;

	*len = irec.ar_blockcount;

	return 0;



out_bad_rec:

	xfs_warn(mp,

		"%s Freespace BTree record corruption in AG %d detected!",

		"%s Freespace BTree record corruption in AG %d detected at %pS!",

		cur->bc_btnum == XFS_BTNUM_BNO ? "Block" : "Size",

		pag->pag_agno);

		pag->pag_agno, fa);

	xfs_warn(mp,

		"start block 0x%x block count 0x%x", *bno, *len);

		"start block 0x%x block count 0x%x", irec.ar_startblock,

		irec.ar_blockcount);

	return -EFSCORRUPTED;

}
@@ -3665,8 +3693,10 @@ xfs_alloc_query_range_helper( 
	struct xfs_alloc_query_range_info	*query = priv;

	struct xfs_alloc_rec_incore		irec;



	irec.ar_startblock = be32_to_cpu(rec->alloc.ar_startblock);

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

	xfs_alloc_btrec_to_irec(rec, &irec);

	if (xfs_alloc_check_irec(cur, &irec) != NULL)

		return -EFSCORRUPTED;



	return query->fn(cur, &irec, query->priv);

}

fs/xfs/libxfs/xfs_alloc.h

+6 −0
Original line number Diff line number Diff line
@@ -181,6 +181,12 @@ xfs_alloc_get_rec( 
	xfs_extlen_t		*len,	/* output: length of extent */

	int			*stat);	/* output: success/failure */



union xfs_btree_rec;

void xfs_alloc_btrec_to_irec(const union xfs_btree_rec *rec,

		struct xfs_alloc_rec_incore *irec);

xfs_failaddr_t xfs_alloc_check_irec(struct xfs_btree_cur *cur,

		const struct xfs_alloc_rec_incore *irec);



int xfs_read_agf(struct xfs_perag *pag, struct xfs_trans *tp, int flags,

		struct xfs_buf **agfbpp);

int xfs_alloc_read_agf(struct xfs_perag *pag, struct xfs_trans *tp, int flags,

fs/xfs/scrub/alloc.c

+12 −12
Original line number Diff line number Diff line
@@ -78,9 +78,11 @@ xchk_allocbt_xref_other( 
STATIC void

xchk_allocbt_xref(

	struct xfs_scrub	*sc,

	xfs_agblock_t		agbno,

	xfs_extlen_t		len)

	const struct xfs_alloc_rec_incore *irec)

{

	xfs_agblock_t		agbno = irec->ar_startblock;

	xfs_extlen_t		len = irec->ar_blockcount;



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

		return;
@@ -96,17 +98,15 @@ xchk_allocbt_rec( 
	struct xchk_btree		*bs,

	const union xfs_btree_rec	*rec)

{

	struct xfs_perag	*pag = bs->cur->bc_ag.pag;

	xfs_agblock_t		bno;

	xfs_extlen_t		len;

	struct xfs_alloc_rec_incore	irec;



	bno = be32_to_cpu(rec->alloc.ar_startblock);

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



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

	xfs_alloc_btrec_to_irec(rec, &irec);

	if (xfs_alloc_check_irec(bs->cur, &irec) != NULL) {

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

		return 0;

	}



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

	xchk_allocbt_xref(bs->sc, &irec);



	return 0;

}