Re: [PATCH 14/22] xfs: scrub inode block mappings

[Allison Henderson <allison.henderson@oracle.com>]

On 7/20/2017 9:40 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Scrub an individual inode's block mappings to make sure they make sense.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/Makefile        |    1
>  fs/xfs/libxfs/xfs_fs.h |    5 +
>  fs/xfs/scrub/bmap.c    |  378 ++++++++++++++++++++++++++++++++++++++++++++++++
>  fs/xfs/scrub/common.c  |   12 ++
>  fs/xfs/scrub/common.h  |    5 +
>  fs/xfs/xfs_trace.h     |    5 +
>  6 files changed, 404 insertions(+), 2 deletions(-)
>  create mode 100644 fs/xfs/scrub/bmap.c
>
>
> diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
> index 2ba33ad..89c67e1a 100644
> --- a/fs/xfs/Makefile
> +++ b/fs/xfs/Makefile
> @@ -142,6 +142,7 @@ ifeq ($(CONFIG_XFS_ONLINE_SCRUB),y)
>  xfs-y				+= $(addprefix scrub/, \
>  				   agheader.o \
>  				   alloc.o \
> +				   bmap.o \
>  				   btree.o \
>  				   common.o \
>  				   ialloc.o \
> diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> index 277b528..d762277 100644
> --- a/fs/xfs/libxfs/xfs_fs.h
> +++ b/fs/xfs/libxfs/xfs_fs.h
> @@ -494,7 +494,10 @@ struct xfs_scrub_metadata {
>  #define XFS_SCRUB_TYPE_RMAPBT	10	/* reverse mapping btree */
>  #define XFS_SCRUB_TYPE_REFCNTBT	11	/* reference count btree */
>  #define XFS_SCRUB_TYPE_INODE	12	/* inode record */
> -#define XFS_SCRUB_TYPE_MAX	12
> +#define XFS_SCRUB_TYPE_BMBTD	13	/* data fork block mapping */
> +#define XFS_SCRUB_TYPE_BMBTA	14	/* attr fork block mapping */
> +#define XFS_SCRUB_TYPE_BMBTC	15	/* CoW fork block mapping */
> +#define XFS_SCRUB_TYPE_MAX	15
>
>  /* i: repair this metadata */
>  #define XFS_SCRUB_FLAG_REPAIR		(1 << 0)
> diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c
> new file mode 100644
> index 0000000..731f026
> --- /dev/null
> +++ b/fs/xfs/scrub/bmap.c
> @@ -0,0 +1,378 @@
> +/*
> + * Copyright (C) 2017 Oracle.  All Rights Reserved.
> + *
> + * Author: Darrick J. Wong <darrick.wong@oracle.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it would be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write the Free Software Foundation,
> + * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
> + */
> +#include "xfs.h"
> +#include "xfs_fs.h"
> +#include "xfs_shared.h"
> +#include "xfs_format.h"
> +#include "xfs_trans_resv.h"
> +#include "xfs_mount.h"
> +#include "xfs_defer.h"
> +#include "xfs_btree.h"
> +#include "xfs_bit.h"
> +#include "xfs_log_format.h"
> +#include "xfs_trans.h"
> +#include "xfs_trace.h"
> +#include "xfs_sb.h"
> +#include "xfs_inode.h"
> +#include "xfs_inode_fork.h"
> +#include "xfs_bmap.h"
> +#include "xfs_bmap_util.h"
> +#include "xfs_bmap_btree.h"
> +#include "xfs_rmap.h"
> +#include "scrub/common.h"
> +#include "scrub/btree.h"
> +
> +/* Set us up with an inode's bmap. */
> +STATIC int
> +__xfs_scrub_setup_inode_bmap(
> +	struct xfs_scrub_context	*sc,
> +	struct xfs_inode		*ip,
> +	bool				flush_data)
> +{
> +	struct xfs_mount		*mp = sc->mp;
> +	int				error;
> +
> +	error = xfs_scrub_get_inode(sc, ip);
> +	if (error)
> +		return error;
> +
> +	sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
> +	xfs_ilock(sc->ip, sc->ilock_flags);
> +
> +	/*
> +	 * We don't want any ephemeral data fork updates sitting around
> +	 * while we inspect block mappings, so wait for directio to finish
> +	 * and flush dirty data if we have delalloc reservations.
> +	 */
> +	if (S_ISREG(VFS_I(sc->ip)->i_mode) && flush_data) {
> +		inode_dio_wait(VFS_I(sc->ip));
> +		error = filemap_write_and_wait(VFS_I(sc->ip)->i_mapping);
> +		if (error)
> +			goto out_unlock;
> +		error = invalidate_inode_pages2(VFS_I(sc->ip)->i_mapping);
> +		if (error)
> +			goto out_unlock;
> +	}
> +
> +	/* Got the inode, lock it and we're ready to go. */
> +	error = xfs_scrub_trans_alloc(sc->sm, mp, &M_RES(mp)->tr_itruncate,
> +			0, 0, 0, &sc->tp);
> +	if (error)
> +		goto out_unlock;
> +	sc->ilock_flags |= XFS_ILOCK_EXCL;
> +	xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
> +
> +	return 0;
> +out_unlock:
> +	xfs_iunlock(sc->ip, sc->ilock_flags);
> +	if (sc->ip != ip)
> +		IRELE(sc->ip);
> +	sc->ip = NULL;
> +	return error;
> +}
> +
> +/* Set us up to scrub the data fork. */
> +int
> +xfs_scrub_setup_inode_bmap_data(
> +	struct xfs_scrub_context	*sc,
> +	struct xfs_inode		*ip)
> +{
> +	return __xfs_scrub_setup_inode_bmap(sc, ip, true);
> +}
> +
> +/* Set us up to scrub the attr or CoW fork. */
> +int
> +xfs_scrub_setup_inode_bmap(
> +	struct xfs_scrub_context	*sc,
> +	struct xfs_inode		*ip)
> +{
> +	return __xfs_scrub_setup_inode_bmap(sc, ip, false);
> +}
> +
> +/*
> + * Inode fork block mapping (BMBT) scrubber.
> + * More complex than the others because we have to scrub
> + * all the extents regardless of whether or not the fork
> + * is in btree format.
> + */
> +
> +struct xfs_scrub_bmap_info {
> +	struct xfs_scrub_context	*sc;
> +	const char			*type;
> +	xfs_daddr_t			eofs;
> +	xfs_fileoff_t			lastoff;
> +	bool				is_rt;
> +	bool				is_shared;
> +	int				whichfork;
> +};
> +
> +#define XFS_SCRUB_BMAP_CHECK(fs_ok) \
> +	XFS_SCRUB_INO_CHECK(info->sc, info->sc->ip->i_ino, bp, info->type, fs_ok)
> +#define XFS_SCRUB_BMAP_GOTO(fs_ok, label) \
> +	XFS_SCRUB_INO_GOTO(info->sc, info->sc->ip->i_ino, bp, info->type, fs_ok, label)
> +#define XFS_SCRUB_BMAP_OP_ERROR_GOTO(label) \
> +	XFS_SCRUB_OP_ERROR_GOTO(info->sc, agno, 0, "bmap", &error, label)
> +/* Scrub a single extent record. */
> +STATIC int
> +xfs_scrub_bmap_extent(
> +	struct xfs_inode		*ip,
> +	struct xfs_btree_cur		*cur,
> +	struct xfs_scrub_bmap_info	*info,
> +	struct xfs_bmbt_irec		*irec)
> +{
> +	struct xfs_scrub_ag		sa = { 0 };
> +	struct xfs_mount		*mp = info->sc->mp;
> +	struct xfs_buf			*bp = NULL;
> +	xfs_daddr_t			daddr;
> +	xfs_daddr_t			dlen;
> +	xfs_fsblock_t			bno;
> +	xfs_agnumber_t			agno;
> +	int				error = 0;
> +
> +	if (cur)
> +		xfs_btree_get_block(cur, 0, &bp);
> +
> +	XFS_SCRUB_BMAP_CHECK(irec->br_startoff >= info->lastoff);
> +	XFS_SCRUB_BMAP_CHECK(irec->br_startblock != HOLESTARTBLOCK);
> +	XFS_SCRUB_BMAP_CHECK(!isnullstartblock(irec->br_startblock));
> +
> +	/* Actual mapping, so check the block ranges. */
> +	if (info->is_rt) {
> +		daddr = XFS_FSB_TO_BB(mp, irec->br_startblock);
> +		agno = NULLAGNUMBER;
> +		bno = irec->br_startblock;
> +	} else {
> +		daddr = XFS_FSB_TO_DADDR(mp, irec->br_startblock);
> +		agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock);
> +		XFS_SCRUB_BMAP_GOTO(agno < mp->m_sb.sb_agcount, out);
> +		bno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
> +		XFS_SCRUB_BMAP_CHECK(bno < mp->m_sb.sb_agblocks);
> +	}
> +	dlen = XFS_FSB_TO_BB(mp, irec->br_blockcount);
> +	XFS_SCRUB_BMAP_CHECK(irec->br_blockcount > 0);
> +	XFS_SCRUB_BMAP_CHECK(irec->br_blockcount <= MAXEXTLEN);
> +	XFS_SCRUB_BMAP_CHECK(daddr < info->eofs);
> +	XFS_SCRUB_BMAP_CHECK(daddr + dlen <= info->eofs);
> +	XFS_SCRUB_BMAP_CHECK(irec->br_state != XFS_EXT_UNWRITTEN ||
> +			xfs_sb_version_hasextflgbit(&mp->m_sb));
> +	if (error)
> +		goto out;
> +
> +	/* Set ourselves up for cross-referencing later. */
> +	if (!info->is_rt) {
> +		error = xfs_scrub_ag_init(info->sc, agno, &sa);
> +		XFS_SCRUB_BMAP_OP_ERROR_GOTO(out);
> +	}
> +
> +	xfs_scrub_ag_free(info->sc, &sa);
> +out:
> +	info->lastoff = irec->br_startoff + irec->br_blockcount;
> +	return error;
> +}
> +#undef XFS_SCRUB_BMAP_OP_ERROR_GOTO
> +#undef XFS_SCRUB_BMAP_GOTO
> +
> +/* Scrub a bmbt record. */
> +STATIC int
> +xfs_scrub_bmapbt_helper(
> +	struct xfs_scrub_btree		*bs,
> +	union xfs_btree_rec		*rec)
> +{
> +	struct xfs_bmbt_rec_host	ihost;
> +	struct xfs_bmbt_irec		irec;
> +	struct xfs_scrub_bmap_info	*info = bs->private;
> +	struct xfs_inode		*ip = bs->cur->bc_private.b.ip;
> +	struct xfs_buf			*bp = NULL;
> +	struct xfs_btree_block		*block;
> +	uint64_t			owner;
> +	int				i;
> +
> +	/*
> +	 * Check the owners of the btree blocks up to the level below
> +	 * the root since the verifiers don't do that.
> +	 */
> +	if (xfs_sb_version_hascrc(&bs->cur->bc_mp->m_sb) &&
> +	    bs->cur->bc_ptrs[0] == 1) {
> +		for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
> +			block = xfs_btree_get_block(bs->cur, i, &bp);
> +			owner = be64_to_cpu(block->bb_u.l.bb_owner);
> +			XFS_SCRUB_BMAP_CHECK(owner == ip->i_ino);
> +		}
> +	}
> +
> +	/* Set up the in-core record and scrub it. */
> +	ihost.l0 = be64_to_cpu(rec->bmbt.l0);
> +	ihost.l1 = be64_to_cpu(rec->bmbt.l1);
> +	xfs_bmbt_get_all(&ihost, &irec);
> +	return xfs_scrub_bmap_extent(ip, bs->cur, info, &irec);
> +}
> +#undef XFS_SCRUB_BMAP_CHECK
> +
> +#define XFS_SCRUB_FORK_CHECK(fs_ok) \
> +	XFS_SCRUB_INO_CHECK(sc, ip->i_ino, NULL, info.type, fs_ok)
> +#define XFS_SCRUB_FORK_GOTO(fs_ok, label) \
> +	XFS_SCRUB_INO_GOTO(sc, ip->i_ino, NULL, info.type, fs_ok, label)
> +#define XFS_SCRUB_FORK_OP_ERROR_GOTO(label) \
> +	XFS_SCRUB_OP_ERROR_GOTO(sc, \
> +			XFS_INO_TO_AGNO(mp, ip->i_ino), \
> +			XFS_INO_TO_AGBNO(mp, ip->i_ino), \
> +			info.type, &error, label)
> +/* Scrub an inode fork's block mappings. */
> +STATIC int
> +xfs_scrub_bmap(
> +	struct xfs_scrub_context	*sc,
> +	int				whichfork)
> +{
> +	struct xfs_bmbt_irec		irec;
> +	struct xfs_scrub_bmap_info	info = {0};
> +	struct xfs_owner_info		oinfo;
> +	struct xfs_mount		*mp = sc->mp;
> +	struct xfs_inode		*ip = sc->ip;
> +	struct xfs_ifork		*ifp;
> +	struct xfs_btree_cur		*cur;
> +	xfs_fileoff_t			endoff;
> +	xfs_extnum_t			idx;
> +	bool				found;
> +	int				error = 0;
> +	int				err2 = 0;
> +
> +	switch (whichfork) {
> +	case XFS_DATA_FORK:
> +		info.type = "data fork";
> +		break;
> +	case XFS_ATTR_FORK:
> +		info.type = "attr fork";
> +		break;
> +	case XFS_COW_FORK:
> +		info.type = "CoW fork";
> +		break;
> +	}
> +	ifp = XFS_IFORK_PTR(ip, whichfork);
> +
> +	info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip);
> +	info.eofs = XFS_FSB_TO_BB(mp, info.is_rt ? mp->m_sb.sb_rblocks :
> +					      mp->m_sb.sb_dblocks);
> +	info.whichfork = whichfork;
> +	info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
> +	info.sc = sc;
> +
> +	switch (whichfork) {
> +	case XFS_COW_FORK:
> +		/* Non-existent CoW forks are ignorable. */
> +		if (!ifp)
> +			goto out_unlock;
> +		/* No CoW forks on non-reflink inodes/filesystems. */
> +		XFS_SCRUB_FORK_GOTO(xfs_is_reflink_inode(ip), out_unlock);
> +		break;
> +	case XFS_ATTR_FORK:
> +		if (!ifp)
> +			goto out_unlock;
> +		XFS_SCRUB_FORK_CHECK(xfs_sb_version_hasattr(&mp->m_sb) ||
> +				     xfs_sb_version_hasattr2(&mp->m_sb));
> +		break;
> +	}
> +
> +	/* Check the fork values */
> +	switch (XFS_IFORK_FORMAT(ip, whichfork)) {
> +	case XFS_DINODE_FMT_UUID:
> +	case XFS_DINODE_FMT_DEV:
> +	case XFS_DINODE_FMT_LOCAL:
> +		/* No mappings to check. */
> +		goto out_unlock;
> +	case XFS_DINODE_FMT_EXTENTS:
> +		XFS_SCRUB_FORK_GOTO(ifp->if_flags & XFS_IFEXTENTS, out_unlock);
> +		break;
> +	case XFS_DINODE_FMT_BTREE:
> +		XFS_SCRUB_FORK_CHECK(whichfork != XFS_COW_FORK);
> +		/* Scan the btree records. */
> +		cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
> +		xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
> +		err2 = xfs_scrub_btree(sc, cur, xfs_scrub_bmapbt_helper,
> +				&oinfo, &info);
> +		xfs_btree_del_cursor(cur, err2 ? XFS_BTREE_ERROR :
> +						 XFS_BTREE_NOERROR);
> +		if (err2 == -EDEADLOCK)
> +			return err2;
> +		else if (err2)
> +			goto out_unlock;
> +		break;
> +	default:
> +		XFS_SCRUB_FORK_GOTO(false, out_unlock);
> +		break;
> +	}
> +
> +	/* Extent data is in memory, so scrub that. */
> +
> +	/* Find the offset of the last extent in the mapping. */
> +	error = xfs_bmap_last_offset(ip, &endoff, whichfork);
> +	XFS_SCRUB_FORK_OP_ERROR_GOTO(out_unlock);
> +
> +	/* Scrub extent records. */
> +	info.lastoff = 0;
> +	ifp = XFS_IFORK_PTR(ip, whichfork);
> +	for (found = xfs_iext_lookup_extent(ip, ifp, 0, &idx, &irec);
> +	     found;
Did you mean to have the found; without an assignment here?  Not sure if 
that was intentional or a typo.

Otherwise looks good.
Reviewed by: Allison Henderson <allison.henderson@oracle.com>
> +	     found = xfs_iext_get_extent(ifp, ++idx, &irec)) {
> +		if (xfs_scrub_should_terminate(&error))
> +			break;
> +		if (isnullstartblock(irec.br_startblock))
> +			continue;
> +		XFS_SCRUB_FORK_CHECK(irec.br_startoff < endoff);
> +		err2 = xfs_scrub_bmap_extent(ip, NULL, &info, &irec);
> +		if (err2 == -EDEADLOCK)
> +			return err2;
> +		else if (!error && err2)
> +			error = err2;
> +	}
> +
> +out_unlock:
> +	if (error == 0 && err2 != 0)
> +		error = err2;
> +	return error;
> +}
> +#undef XFS_SCRUB_FORK_CHECK
> +#undef XFS_SCRUB_FORK_GOTO
> +
> +/* Scrub an inode's data fork. */
> +int
> +xfs_scrub_bmap_data(
> +	struct xfs_scrub_context	*sc)
> +{
> +	return xfs_scrub_bmap(sc, XFS_DATA_FORK);
> +}
> +
> +/* Scrub an inode's attr fork. */
> +int
> +xfs_scrub_bmap_attr(
> +	struct xfs_scrub_context	*sc)
> +{
> +	return xfs_scrub_bmap(sc, XFS_ATTR_FORK);
> +}
> +
> +/* Scrub an inode's CoW fork. */
> +int
> +xfs_scrub_bmap_cow(
> +	struct xfs_scrub_context	*sc)
> +{
> +	if (!xfs_is_reflink_inode(sc->ip))
> +		return -ENOENT;
> +
> +	return xfs_scrub_bmap(sc, XFS_COW_FORK);
> +}
> diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
> index 066fd3e..da3c006 100644
> --- a/fs/xfs/scrub/common.c
> +++ b/fs/xfs/scrub/common.c
> @@ -795,6 +795,18 @@ static const struct xfs_scrub_meta_fns meta_scrub_fns[] = {
>  		.setup	= xfs_scrub_setup_inode,
>  		.scrub	= xfs_scrub_inode,
>  	},
> +	{ /* inode data fork */
> +		.setup	= xfs_scrub_setup_inode_bmap_data,
> +		.scrub	= xfs_scrub_bmap_data,
> +	},
> +	{ /* inode attr fork */
> +		.setup	= xfs_scrub_setup_inode_bmap,
> +		.scrub	= xfs_scrub_bmap_attr,
> +	},
> +	{ /* inode CoW fork */
> +		.setup	= xfs_scrub_setup_inode_bmap,
> +		.scrub	= xfs_scrub_bmap_cow,
> +	},
>  };
>
>  /* Dispatch metadata scrubbing. */
> diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
> index 5caa6c9..1025466 100644
> --- a/fs/xfs/scrub/common.h
> +++ b/fs/xfs/scrub/common.h
> @@ -216,6 +216,8 @@ SETUP_FN(xfs_scrub_setup_ag_iallocbt);
>  SETUP_FN(xfs_scrub_setup_ag_rmapbt);
>  SETUP_FN(xfs_scrub_setup_ag_refcountbt);
>  SETUP_FN(xfs_scrub_setup_inode);
> +SETUP_FN(xfs_scrub_setup_inode_bmap_data);
> +SETUP_FN(xfs_scrub_setup_inode_bmap);
>  #undef SETUP_FN
>
>  /* Metadata scrubbers */
> @@ -234,6 +236,9 @@ SCRUB_FN(xfs_scrub_finobt);
>  SCRUB_FN(xfs_scrub_rmapbt);
>  SCRUB_FN(xfs_scrub_refcountbt);
>  SCRUB_FN(xfs_scrub_inode);
> +SCRUB_FN(xfs_scrub_bmap_data);
> +SCRUB_FN(xfs_scrub_bmap_attr);
> +SCRUB_FN(xfs_scrub_bmap_cow);
>  #undef SCRUB_FN
>
>  #endif	/* __XFS_REPAIR_COMMON_H__ */
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index 950e2c8..edfa4c7 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -3324,7 +3324,10 @@ DEFINE_GETFSMAP_EVENT(xfs_getfsmap_mapping);
>  	{ XFS_SCRUB_TYPE_FINOBT,	"finobt" }, \
>  	{ XFS_SCRUB_TYPE_RMAPBT,	"rmapbt" }, \
>  	{ XFS_SCRUB_TYPE_REFCNTBT,	"refcountbt" }, \
> -	{ XFS_SCRUB_TYPE_INODE,		"inode" }
> +	{ XFS_SCRUB_TYPE_INODE,		"inode" }, \
> +	{ XFS_SCRUB_TYPE_BMBTD,		"bmapbtd" }, \
> +	{ XFS_SCRUB_TYPE_BMBTA,		"bmapbta" }, \
> +	{ XFS_SCRUB_TYPE_BMBTC,		"bmapbtc" }
>  DECLARE_EVENT_CLASS(xfs_scrub_class,
>  	TP_PROTO(struct xfs_inode *ip, struct xfs_scrub_metadata *sm,
>  		 int error),
>
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