[PATCH 32/53] xfs_repair: add fixed-location per-AG rmaps

[Darrick J. Wong]

Add reverse-mappings for fixed-location per-AG metadata such as inode
chunks, superblocks, and the log to the raw rmap list, then merge the
raw rmap data (which also has the BMBT data) into the main rmap list.

v2: Support sparse inode chunks.

Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
---
 repair/phase4.c |   41 +++++++++++++++++++++++++
 repair/rmap.c   |   91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 repair/rmap.h   |    2 +
 3 files changed, 134 insertions(+)


diff --git a/repair/phase4.c b/repair/phase4.c
index bc43cd8..cbdb92e 100644
--- a/repair/phase4.c
+++ b/repair/phase4.c
@@ -157,6 +157,40 @@ process_ags(
 	do_inode_prefetch(mp, ag_stride, process_ag_func, true, false);
 }
 
+static void
+check_rmap_btrees(
+	work_queue_t	*wq,
+	xfs_agnumber_t	agno,
+	void		*arg)
+{
+	int		error;
+
+	error = add_fixed_ag_rmap_data(wq->mp, agno);
+	if (error)
+		do_error(
+_("unable to add AG %u metadata reverse-mapping data.\n"), agno);
+
+	error = fold_raw_rmaps(wq->mp, agno);
+	if (error)
+		do_error(
+_("unable to merge AG %u metadata reverse-mapping data.\n"), agno);
+}
+
+static void
+process_rmap_data(
+	struct xfs_mount	*mp)
+{
+	struct work_queue	wq;
+	xfs_agnumber_t		i;
+
+	if (!needs_rmap_work(mp))
+		return;
+
+	create_work_queue(&wq, mp, libxfs_nproc());
+	for (i = 0; i < mp->m_sb.sb_agcount; i++)
+		queue_work(&wq, check_rmap_btrees, i, NULL);
+	destroy_work_queue(&wq);
+}
 
 void
 phase4(xfs_mount_t *mp)
@@ -306,6 +340,13 @@ phase4(xfs_mount_t *mp)
 	 * already in phase 3.
 	 */
 	process_ags(mp);
+
+	/*
+	 * Process all the reverse-mapping data that we collected.  This
+	 * involves checking the rmap data against the btree.
+	 */
+	process_rmap_data(mp);
+
 	print_final_rpt();
 
 	/*
diff --git a/repair/rmap.c b/repair/rmap.c
index 40bdae3..e13fc53 100644
--- a/repair/rmap.c
+++ b/repair/rmap.c
@@ -344,6 +344,97 @@ err:
 	return error;
 }
 
+static int
+find_first_zero_bit(
+	__uint64_t	mask)
+{
+	int		n;
+	int		b = 0;
+
+	for (n = 0; n < sizeof(mask) * NBBY && (mask & 1); n++, mask >>= 1)
+		b++;
+
+	return b;
+}
+
+static int
+popcnt(
+	__uint64_t	mask)
+{
+	int		n;
+	int		b = 0;
+
+	if (mask == 0)
+		return 0;
+
+	for (n = 0; n < sizeof(mask) * NBBY; n++, mask >>= 1)
+		if (mask & 1)
+			b++;
+
+	return b;
+}
+
+/**
+ * add_fixed_ag_rmap_data() - Add fixed per-AG metadata to the rmap list.
+ *			      This includes sb/agi/agf/agfl headers, inode
+ *			      chunks, and the log.
+ *
+ * @mp: XFS mountpoint.
+ * @agno: AG number.
+ */
+int
+add_fixed_ag_rmap_data(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno)
+{
+	xfs_fsblock_t		fsbno;
+	xfs_agblock_t		agbno;
+	ino_tree_node_t		*ino_rec;
+	xfs_agino_t		agino;
+	int			error;
+	int			startidx;
+	int			nr;
+
+	if (!needs_rmap_work(mp))
+		return 0;
+
+	/* sb/agi/agf/agfl headers */
+	error = add_ag_rmap(mp, agno, 0, XFS_BNO_BLOCK(mp),
+			XFS_RMAP_OWN_FS);
+	if (error)
+		goto out;
+
+	/* inodes */
+	ino_rec = findfirst_inode_rec(agno);
+	for (; ino_rec != NULL; ino_rec = next_ino_rec(ino_rec)) {
+		if (xfs_sb_version_hassparseinodes(&mp->m_sb)) {
+			startidx = find_first_zero_bit(ino_rec->ir_sparse);
+			nr = XFS_INODES_PER_CHUNK - popcnt(ino_rec->ir_sparse);
+		} else {
+			startidx = 0;
+			nr = XFS_INODES_PER_CHUNK;
+		}
+		agino = ino_rec->ino_startnum + startidx;
+		agbno = XFS_AGINO_TO_AGBNO(mp, agino);
+		error = add_ag_rmap(mp, agno, agbno, nr / mp->m_sb.sb_inopblock,
+				XFS_RMAP_OWN_INODES);
+		if (error)
+			goto out;
+	}
+
+	/* log */
+	fsbno = mp->m_sb.sb_logstart;
+	if (fsbno && XFS_FSB_TO_AGNO(mp, fsbno) == agno) {
+		agbno = XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart);
+		error = add_ag_rmap(mp, agno, agbno, mp->m_sb.sb_logblocks,
+				XFS_RMAP_OWN_LOG);
+		if (error)
+			goto out;
+	}
+out:
+	return error;
+}
+
 #ifdef RMAP_DEBUG
 static void
 dump_rmap(
diff --git a/repair/rmap.h b/repair/rmap.h
index 57d56a0..7bab450 100644
--- a/repair/rmap.h
+++ b/repair/rmap.h
@@ -31,4 +31,6 @@ extern int add_ag_rmap(struct xfs_mount *, xfs_agnumber_t agno,
 extern int add_bmbt_rmap(struct xfs_mount *, xfs_ino_t, int, xfs_fsblock_t);
 extern int fold_raw_rmaps(struct xfs_mount *mp, xfs_agnumber_t agno);
 
+extern int add_fixed_ag_rmap_data(struct xfs_mount *, xfs_agnumber_t);
+
 #endif /* RMAP_H_ */