1 files changed, 169 insertions, 1 deletions

diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c
index d00282130492..75ea2d63429c 100644
--- a/fs/xfs/scrub/bmap.c
+++ b/fs/xfs/scrub/bmap.c
@@ -37,6 +37,7 @@
 #include "xfs_bmap_util.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
 #include "xfs_refcount.h"
 #include "scrub/xfs_scrub.h"
 #include "scrub/scrub.h"
@@ -423,6 +424,169 @@ xfs_scrub_bmap_btree(
 	return error;
 }
 
+struct xfs_scrub_bmap_check_rmap_info {
+	struct xfs_scrub_context	*sc;
+	int				whichfork;
+	struct xfs_iext_cursor		icur;
+};
+
+/* Can we find bmaps that fit this rmap? */
+STATIC int
+xfs_scrub_bmap_check_rmap(
+	struct xfs_btree_cur		*cur,
+	struct xfs_rmap_irec		*rec,
+	void				*priv)
+{
+	struct xfs_bmbt_irec		irec;
+	struct xfs_scrub_bmap_check_rmap_info	*sbcri = priv;
+	struct xfs_ifork		*ifp;
+	struct xfs_scrub_context	*sc = sbcri->sc;
+	bool				have_map;
+
+	/* Is this even the right fork? */
+	if (rec->rm_owner != sc->ip->i_ino)
+		return 0;
+	if ((sbcri->whichfork == XFS_ATTR_FORK) ^
+	    !!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
+		return 0;
+	if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
+		return 0;
+
+	/* Now look up the bmbt record. */
+	ifp = XFS_IFORK_PTR(sc->ip, sbcri->whichfork);
+	if (!ifp) {
+		xfs_scrub_fblock_set_corrupt(sc, sbcri->whichfork,
+				rec->rm_offset);
+		goto out;
+	}
+	have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
+			&sbcri->icur, &irec);
+	if (!have_map)
+		xfs_scrub_fblock_set_corrupt(sc, sbcri->whichfork,
+				rec->rm_offset);
+	/*
+	 * bmap extent record lengths are constrained to 2^21 blocks in length
+	 * because of space constraints in the on-disk metadata structure.
+	 * However, rmap extent record lengths are constrained only by AG
+	 * length, so we have to loop through the bmbt to make sure that the
+	 * entire rmap is covered by bmbt records.
+	 */
+	while (have_map) {
+		if (irec.br_startoff != rec->rm_offset)
+			xfs_scrub_fblock_set_corrupt(sc, sbcri->whichfork,
+					rec->rm_offset);
+		if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
+				cur->bc_private.a.agno, rec->rm_startblock))
+			xfs_scrub_fblock_set_corrupt(sc, sbcri->whichfork,
+					rec->rm_offset);
+		if (irec.br_blockcount > rec->rm_blockcount)
+			xfs_scrub_fblock_set_corrupt(sc, sbcri->whichfork,
+					rec->rm_offset);
+		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+			break;
+		rec->rm_startblock += irec.br_blockcount;
+		rec->rm_offset += irec.br_blockcount;
+		rec->rm_blockcount -= irec.br_blockcount;
+		if (rec->rm_blockcount == 0)
+			break;
+		have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
+		if (!have_map)
+			xfs_scrub_fblock_set_corrupt(sc, sbcri->whichfork,
+					rec->rm_offset);
+	}
+
+out:
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return XFS_BTREE_QUERY_RANGE_ABORT;
+	return 0;
+}
+
+/* Make sure each rmap has a corresponding bmbt entry. */
+STATIC int
+xfs_scrub_bmap_check_ag_rmaps(
+	struct xfs_scrub_context	*sc,
+	int				whichfork,
+	xfs_agnumber_t			agno)
+{
+	struct xfs_scrub_bmap_check_rmap_info	sbcri;
+	struct xfs_btree_cur		*cur;
+	struct xfs_buf			*agf;
+	int				error;
+
+	error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf);
+	if (error)
+		return error;
+
+	cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, agno);
+	if (!cur) {
+		error = -ENOMEM;
+		goto out_agf;
+	}
+
+	sbcri.sc = sc;
+	sbcri.whichfork = whichfork;
+	error = xfs_rmap_query_all(cur, xfs_scrub_bmap_check_rmap, &sbcri);
+	if (error == XFS_BTREE_QUERY_RANGE_ABORT)
+		error = 0;
+
+	xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+out_agf:
+	xfs_trans_brelse(sc->tp, agf);
+	return error;
+}
+
+/* Make sure each rmap has a corresponding bmbt entry. */
+STATIC int
+xfs_scrub_bmap_check_rmaps(
+	struct xfs_scrub_context	*sc,
+	int				whichfork)
+{
+	loff_t				size;
+	xfs_agnumber_t			agno;
+	int				error;
+
+	if (!xfs_sb_version_hasrmapbt(&sc->mp->m_sb) ||
+	    whichfork == XFS_COW_FORK ||
+	    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+		return 0;
+
+	/* Don't support realtime rmap checks yet. */
+	if (XFS_IS_REALTIME_INODE(sc->ip) && whichfork == XFS_DATA_FORK)
+		return 0;
+
+	/*
+	 * Only do this for complex maps that are in btree format, or for
+	 * situations where we would seem to have a size but zero extents.
+	 * The inode repair code can zap broken iforks, which means we have
+	 * to flag this bmap as corrupt if there are rmaps that need to be
+	 * reattached.
+	 */
+	switch (whichfork) {
+	case XFS_DATA_FORK:
+		size = i_size_read(VFS_I(sc->ip));
+		break;
+	case XFS_ATTR_FORK:
+		size = XFS_IFORK_Q(sc->ip);
+		break;
+	default:
+		size = 0;
+		break;
+	}
+	if (XFS_IFORK_FORMAT(sc->ip, whichfork) != XFS_DINODE_FMT_BTREE &&
+	    (size == 0 || XFS_IFORK_NEXTENTS(sc->ip, whichfork) > 0))
+		return 0;
+
+	for (agno = 0; agno < sc->mp->m_sb.sb_agcount; agno++) {
+		error = xfs_scrub_bmap_check_ag_rmaps(sc, whichfork, agno);
+		if (error)
+			return error;
+		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+			break;
+	}
+
+	return 0;
+}
+
 /*
  * Scrub an inode fork's block mappings.
  *
@@ -463,7 +627,7 @@ xfs_scrub_bmap(
 		break;
 	case XFS_ATTR_FORK:
 		if (!ifp)
-			goto out;
+			goto out_check_rmap;
 		if (!xfs_sb_version_hasattr(&mp->m_sb) &&
 		    !xfs_sb_version_hasattr2(&mp->m_sb))
 			xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL);
@@ -534,6 +698,10 @@ xfs_scrub_bmap(
 			goto out;
 	}
 
+out_check_rmap:
+	error = xfs_scrub_bmap_check_rmaps(sc, whichfork);
+	if (!xfs_scrub_fblock_xref_process_error(sc, whichfork, 0, &error))
+		goto out;
 out:
 	return error;
 }