Commit b6c1beb9 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: create helpers to scan an allocation group 



Add some helpers to enable us to lock an AG's headers, create btree
cursors for all btrees in that allocation group, and clean up
afterwards.

Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent 37f3fa7f

fs/xfs/scrub/common.c

+179 −0
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 
#include "scrub/scrub.h"

#include "scrub/common.h"

#include "scrub/trace.h"

#include "scrub/btree.h"



/* Common code for the metadata scrubbers. */
@@ -237,6 +238,184 @@ xfs_scrub_set_incomplete( 
	trace_xfs_scrub_incomplete(sc, __return_address);

}



/*

 * AG scrubbing

 *

 * These helpers facilitate locking an allocation group's header

 * buffers, setting up cursors for all btrees that are present, and

 * cleaning everything up once we're through.

 */



/*

 * Grab all the headers for an AG.

 *

 * The headers should be released by xfs_scrub_ag_free, but as a fail

 * safe we attach all the buffers we grab to the scrub transaction so

 * they'll all be freed when we cancel it.

 */

int

xfs_scrub_ag_read_headers(

	struct xfs_scrub_context	*sc,

	xfs_agnumber_t			agno,

	struct xfs_buf			**agi,

	struct xfs_buf			**agf,

	struct xfs_buf			**agfl)

{

	struct xfs_mount		*mp = sc->mp;

	int				error;



	error = xfs_ialloc_read_agi(mp, sc->tp, agno, agi);

	if (error)

		goto out;



	error = xfs_alloc_read_agf(mp, sc->tp, agno, 0, agf);

	if (error)

		goto out;

	if (!*agf) {

		error = -ENOMEM;

		goto out;

	}



	error = xfs_alloc_read_agfl(mp, sc->tp, agno, agfl);

	if (error)

		goto out;



out:

	return error;

}



/* Release all the AG btree cursors. */

void

xfs_scrub_ag_btcur_free(

	struct xfs_scrub_ag		*sa)

{

	if (sa->refc_cur)

		xfs_btree_del_cursor(sa->refc_cur, XFS_BTREE_ERROR);

	if (sa->rmap_cur)

		xfs_btree_del_cursor(sa->rmap_cur, XFS_BTREE_ERROR);

	if (sa->fino_cur)

		xfs_btree_del_cursor(sa->fino_cur, XFS_BTREE_ERROR);

	if (sa->ino_cur)

		xfs_btree_del_cursor(sa->ino_cur, XFS_BTREE_ERROR);

	if (sa->cnt_cur)

		xfs_btree_del_cursor(sa->cnt_cur, XFS_BTREE_ERROR);

	if (sa->bno_cur)

		xfs_btree_del_cursor(sa->bno_cur, XFS_BTREE_ERROR);



	sa->refc_cur = NULL;

	sa->rmap_cur = NULL;

	sa->fino_cur = NULL;

	sa->ino_cur = NULL;

	sa->bno_cur = NULL;

	sa->cnt_cur = NULL;

}



/* Initialize all the btree cursors for an AG. */

int

xfs_scrub_ag_btcur_init(

	struct xfs_scrub_context	*sc,

	struct xfs_scrub_ag		*sa)

{

	struct xfs_mount		*mp = sc->mp;

	xfs_agnumber_t			agno = sa->agno;



	if (sa->agf_bp) {

		/* Set up a bnobt cursor for cross-referencing. */

		sa->bno_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,

				agno, XFS_BTNUM_BNO);

		if (!sa->bno_cur)

			goto err;



		/* Set up a cntbt cursor for cross-referencing. */

		sa->cnt_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,

				agno, XFS_BTNUM_CNT);

		if (!sa->cnt_cur)

			goto err;

	}



	/* Set up a inobt cursor for cross-referencing. */

	if (sa->agi_bp) {

		sa->ino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,

					agno, XFS_BTNUM_INO);

		if (!sa->ino_cur)

			goto err;

	}



	/* Set up a finobt cursor for cross-referencing. */

	if (sa->agi_bp && xfs_sb_version_hasfinobt(&mp->m_sb)) {

		sa->fino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,

				agno, XFS_BTNUM_FINO);

		if (!sa->fino_cur)

			goto err;

	}



	/* Set up a rmapbt cursor for cross-referencing. */

	if (sa->agf_bp && xfs_sb_version_hasrmapbt(&mp->m_sb)) {

		sa->rmap_cur = xfs_rmapbt_init_cursor(mp, sc->tp, sa->agf_bp,

				agno);

		if (!sa->rmap_cur)

			goto err;

	}



	/* Set up a refcountbt cursor for cross-referencing. */

	if (sa->agf_bp && xfs_sb_version_hasreflink(&mp->m_sb)) {

		sa->refc_cur = xfs_refcountbt_init_cursor(mp, sc->tp,

				sa->agf_bp, agno, NULL);

		if (!sa->refc_cur)

			goto err;

	}



	return 0;

err:

	return -ENOMEM;

}



/* Release the AG header context and btree cursors. */

void

xfs_scrub_ag_free(

	struct xfs_scrub_context	*sc,

	struct xfs_scrub_ag		*sa)

{

	xfs_scrub_ag_btcur_free(sa);

	if (sa->agfl_bp) {

		xfs_trans_brelse(sc->tp, sa->agfl_bp);

		sa->agfl_bp = NULL;

	}

	if (sa->agf_bp) {

		xfs_trans_brelse(sc->tp, sa->agf_bp);

		sa->agf_bp = NULL;

	}

	if (sa->agi_bp) {

		xfs_trans_brelse(sc->tp, sa->agi_bp);

		sa->agi_bp = NULL;

	}

	sa->agno = NULLAGNUMBER;

}



/*

 * For scrub, grab the AGI and the AGF headers, in that order.  Locking

 * order requires us to get the AGI before the AGF.  We use the

 * transaction to avoid deadlocking on crosslinked metadata buffers;

 * either the caller passes one in (bmap scrub) or we have to create a

 * transaction ourselves.

 */

int

xfs_scrub_ag_init(

	struct xfs_scrub_context	*sc,

	xfs_agnumber_t			agno,

	struct xfs_scrub_ag		*sa)

{

	int				error;



	sa->agno = agno;

	error = xfs_scrub_ag_read_headers(sc, agno, &sa->agi_bp,

			&sa->agf_bp, &sa->agfl_bp);

	if (error)

		return error;



	return xfs_scrub_ag_btcur_init(sc, sa);

}



/* Per-scrubber setup functions */



/* Set us up with a transaction and an empty context. */

fs/xfs/scrub/common.h

+10 −0
Original line number Diff line number Diff line
@@ -77,4 +77,14 @@ void xfs_scrub_set_incomplete(struct xfs_scrub_context *sc); 
/* Setup functions */

int xfs_scrub_setup_fs(struct xfs_scrub_context *sc, struct xfs_inode *ip);



void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);

int xfs_scrub_ag_init(struct xfs_scrub_context *sc, xfs_agnumber_t agno,

		      struct xfs_scrub_ag *sa);

int xfs_scrub_ag_read_headers(struct xfs_scrub_context *sc, xfs_agnumber_t agno,

			      struct xfs_buf **agi, struct xfs_buf **agf,

			      struct xfs_buf **agfl);

void xfs_scrub_ag_btcur_free(struct xfs_scrub_ag *sa);

int xfs_scrub_ag_btcur_init(struct xfs_scrub_context *sc,

			    struct xfs_scrub_ag *sa);



#endif	/* __XFS_SCRUB_COMMON_H__ */

fs/xfs/scrub/scrub.c

+4 −0
Original line number Diff line number Diff line
@@ -44,6 +44,8 @@ 
#include "scrub/scrub.h"

#include "scrub/common.h"

#include "scrub/trace.h"

#include "scrub/scrub.h"

#include "scrub/btree.h"



/*

 * Online Scrub and Repair
@@ -141,6 +143,7 @@ xfs_scrub_teardown( 
	struct xfs_scrub_context	*sc,

	int				error)

{

	xfs_scrub_ag_free(sc, &sc->sa);

	if (sc->tp) {

		xfs_trans_cancel(sc->tp);

		sc->tp = NULL;
@@ -241,6 +244,7 @@ xfs_scrub_metadata( 
	sc.sm = sm;

	sc.ops = ops;

	sc.try_harder = try_harder;

	sc.sa.agno = NULLAGNUMBER;

	error = sc.ops->setup(&sc, ip);

	if (error)

		goto out_teardown;

fs/xfs/scrub/scrub.h

+21 −0
Original line number Diff line number Diff line
@@ -34,6 +34,24 @@ struct xfs_scrub_meta_ops { 
	bool		(*has)(struct xfs_sb *);

};



/* Buffer pointers and btree cursors for an entire AG. */

struct xfs_scrub_ag {

	xfs_agnumber_t			agno;



	/* AG btree roots */

	struct xfs_buf			*agf_bp;

	struct xfs_buf			*agfl_bp;

	struct xfs_buf			*agi_bp;



	/* AG btrees */

	struct xfs_btree_cur		*bno_cur;

	struct xfs_btree_cur		*cnt_cur;

	struct xfs_btree_cur		*ino_cur;

	struct xfs_btree_cur		*fino_cur;

	struct xfs_btree_cur		*rmap_cur;

	struct xfs_btree_cur		*refc_cur;

};



struct xfs_scrub_context {

	/* General scrub state. */

	struct xfs_mount		*mp;
@@ -42,6 +60,9 @@ struct xfs_scrub_context { 
	struct xfs_trans		*tp;

	struct xfs_inode		*ip;

	bool				try_harder;



	/* State tracking for single-AG operations. */

	struct xfs_scrub_ag		sa;

};



/* Metadata scrubbers */