Commit 04f0c326 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: check rt summary file geometry more thoroughly 



I forgot that the xfs_mount tracks the size and number of levels in the
realtime summary file, and that the rt summary file can have more blocks
mapped to the data fork than m_rsumsize implies if growfsrt fails.

So.  Add to the rtsummary scrubber an explicit check that all the
summary geometry values are correct, then adjust the rtsummary i_size
checks to allow for the growfsrt failure case.  Finally, flag post-eof
blocks in the summary file.

While we're at it, split the extent map checking so that we only call
xfs_bmapi_read once per extent instead of once per rtsummary block.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 41991cf2

fs/xfs/scrub/rtsummary.c

+110 −27
Original line number Diff line number Diff line
@@ -31,6 +31,18 @@ 
 * (potentially large) amount of data in pageable memory.

 */



struct xchk_rtsummary {

	struct xfs_rtalloc_args	args;



	uint64_t		rextents;

	uint64_t		rbmblocks;

	uint64_t		rsumsize;

	unsigned int		rsumlevels;



	/* Memory buffer for the summary comparison. */

	union xfs_suminfo_raw	words[];

};



/* Set us up to check the rtsummary file. */

int

xchk_setup_rtsummary(
@@ -38,8 +50,15 @@ xchk_setup_rtsummary( 
{

	struct xfs_mount	*mp = sc->mp;

	char			*descr;

	struct xchk_rtsummary	*rts;

	int			error;



	rts = kvzalloc(struct_size(rts, words, mp->m_blockwsize),

			XCHK_GFP_FLAGS);

	if (!rts)

		return -ENOMEM;

	sc->buf = rts;



	/*

	 * Create an xfile to construct a new rtsummary file.  The xfile allows

	 * us to avoid pinning kernel memory for this purpose.
@@ -54,11 +73,6 @@ xchk_setup_rtsummary( 
	if (error)

		return error;



	/* Allocate a memory buffer for the summary comparison. */

	sc->buf = kvmalloc(mp->m_sb.sb_blocksize, XCHK_GFP_FLAGS);

	if (!sc->buf)

		return -ENOMEM;



	error = xchk_install_live_inode(sc, mp->m_rsumip);

	if (error)

		return error;
@@ -75,13 +89,29 @@ xchk_setup_rtsummary( 
	 */

	xfs_ilock(mp->m_rbmip, XFS_ILOCK_SHARED | XFS_ILOCK_RTBITMAP);

	xchk_ilock(sc, XFS_ILOCK_EXCL | XFS_ILOCK_RTSUM);



	/*

	 * Now that we've locked the rtbitmap and rtsummary, we can't race with

	 * growfsrt trying to expand the summary or change the size of the rt

	 * volume.  Hence it is safe to compute and check the geometry values.

	 */

	if (mp->m_sb.sb_rblocks) {

		xfs_filblks_t	rsumblocks;

		int		rextslog;



		rts->rextents = xfs_rtb_to_rtx(mp, mp->m_sb.sb_rblocks);

		rextslog = xfs_compute_rextslog(rts->rextents);

		rts->rsumlevels = rextslog + 1;

		rts->rbmblocks = xfs_rtbitmap_blockcount(mp, rts->rextents);

		rsumblocks = xfs_rtsummary_blockcount(mp, rts->rsumlevels,

				rts->rbmblocks);

		rts->rsumsize = XFS_FSB_TO_B(mp, rsumblocks);

	}

	return 0;

}



/* Helper functions to record suminfo words in an xfile. */



typedef unsigned int xchk_rtsumoff_t;



static inline int

xfsum_load(

	struct xfs_scrub	*sc,
@@ -192,28 +222,37 @@ STATIC int 
xchk_rtsum_compare(

	struct xfs_scrub	*sc)

{

	struct xfs_rtalloc_args args = {

		.mp		= sc->mp,

		.tp		= sc->tp,

	};

	struct xfs_mount	*mp = sc->mp;

	struct xfs_bmbt_irec	map;

	xfs_fileoff_t		off;

	xchk_rtsumoff_t		sumoff = 0;

	int			nmap;

	struct xfs_iext_cursor	icur;



	for (off = 0; off < XFS_B_TO_FSB(mp, mp->m_rsumsize); off++) {

		union xfs_suminfo_raw *ondisk_info;

	struct xfs_mount	*mp = sc->mp;

	struct xfs_inode	*ip = sc->ip;

	struct xchk_rtsummary	*rts = sc->buf;

	xfs_fileoff_t		off = 0;

	xfs_fileoff_t		endoff;

	xfs_rtsumoff_t		sumoff = 0;

	int			error = 0;



	rts->args.mp = sc->mp;

	rts->args.tp = sc->tp;



	/* Mappings may not cross or lie beyond EOF. */

	endoff = XFS_B_TO_FSB(mp, ip->i_disk_size);

	if (xfs_iext_lookup_extent(ip, &ip->i_df, endoff, &icur, &map)) {

		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, endoff);

		return 0;

	}



	while (off < endoff) {

		int		nmap = 1;



		if (xchk_should_terminate(sc, &error))

			return error;

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

			return 0;



		/* Make sure we have a written extent. */

		nmap = 1;

		error = xfs_bmapi_read(mp->m_rsumip, off, 1, &map, &nmap,

		error = xfs_bmapi_read(ip, off, endoff - off, &map, &nmap,

				XFS_DATA_FORK);

		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))

			return error;
@@ -223,24 +262,33 @@ xchk_rtsum_compare( 
			return 0;

		}



		off += map.br_blockcount;

	}



	for (off = 0; off < endoff; off++) {

		union xfs_suminfo_raw	*ondisk_info;



		/* Read a block's worth of ondisk rtsummary file. */

		error = xfs_rtsummary_read_buf(&args, off);

		error = xfs_rtsummary_read_buf(&rts->args, off);

		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, off, &error))

			return error;



		/* Read a block's worth of computed rtsummary file. */

		error = xfsum_copyout(sc, sumoff, sc->buf, mp->m_blockwsize);

		error = xfsum_copyout(sc, sumoff, rts->words, mp->m_blockwsize);

		if (error) {

			xfs_rtbuf_cache_relse(&args);

			xfs_rtbuf_cache_relse(&rts->args);

			return error;

		}



		ondisk_info = xfs_rsumblock_infoptr(&args, 0);

		if (memcmp(ondisk_info, sc->buf,

					mp->m_blockwsize << XFS_WORDLOG) != 0)

		ondisk_info = xfs_rsumblock_infoptr(&rts->args, 0);

		if (memcmp(ondisk_info, rts->words,

					mp->m_blockwsize << XFS_WORDLOG) != 0) {

			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, off);

			xfs_rtbuf_cache_relse(&rts->args);

			return error;

		}



		xfs_rtbuf_cache_relse(&args);

		xfs_rtbuf_cache_relse(&rts->args);

		sumoff += mp->m_blockwsize;

	}
@@ -253,8 +301,43 @@ xchk_rtsummary( 
	struct xfs_scrub	*sc)

{

	struct xfs_mount	*mp = sc->mp;

	struct xchk_rtsummary	*rts = sc->buf;

	int			error = 0;



	/* Is sb_rextents correct? */

	if (mp->m_sb.sb_rextents != rts->rextents) {

		xchk_ino_set_corrupt(sc, mp->m_rbmip->i_ino);

		goto out_rbm;

	}



	/* Is m_rsumlevels correct? */

	if (mp->m_rsumlevels != rts->rsumlevels) {

		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);

		goto out_rbm;

	}



	/* Is m_rsumsize correct? */

	if (mp->m_rsumsize != rts->rsumsize) {

		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);

		goto out_rbm;

	}



	/* The summary file length must be aligned to an fsblock. */

	if (mp->m_rsumip->i_disk_size & mp->m_blockmask) {

		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);

		goto out_rbm;

	}



	/*

	 * Is the summary file itself large enough to handle the rt volume?

	 * growfsrt expands the summary file before updating sb_rextents, so

	 * the file can be larger than rsumsize.

	 */

	if (mp->m_rsumip->i_disk_size < rts->rsumsize) {

		xchk_ino_set_corrupt(sc, mp->m_rsumip->i_ino);

		goto out_rbm;

	}



	/* Invoke the fork scrubber. */

	error = xchk_metadata_inode_forks(sc);

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