xfs: add scrub cross-referencing helpers for the inode btrees

Add a couple of functions to the inode btrees that will be used
to cross-reference metadata against the inobt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

2 files changed, 105 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index c01ed9cfc5ae..3625d1da7462 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -2753,3 +2753,102 @@ xfs_verify_dir_ino(
                 return false;
         return xfs_verify_ino(mp, ino);
 }
+
+/* Is there an inode record covering a given range of inode numbers? */
+int
+xfs_ialloc_has_inode_record(
+        struct xfs_btree_cur    *cur,
+        xfs_agino_t             low,
+        xfs_agino_t             high,
+        bool                    *exists)
+{
+        struct xfs_inobt_rec_incore     irec;
+        xfs_agino_t             agino;
+        uint16_t                holemask;
+        int                     has_record;
+        int                     i;
+        int                     error;
+
+        *exists = false;
+        error = xfs_inobt_lookup(cur, low, XFS_LOOKUP_LE, &has_record);
+        while (error == 0 && has_record) {
+                error = xfs_inobt_get_rec(cur, &irec, &has_record);
+                if (error || irec.ir_startino > high)
+                        break;
+
+                agino = irec.ir_startino;
+                holemask = irec.ir_holemask;
+                for (i = 0; i < XFS_INOBT_HOLEMASK_BITS; holemask >>= 1,
+                                i++, agino += XFS_INODES_PER_HOLEMASK_BIT) {
+                        if (holemask & 1)
+                                continue;
+                        if (agino + XFS_INODES_PER_HOLEMASK_BIT > low &&
+                                        agino <= high) {
+                                *exists = true;
+                                return 0;
+                        }
+                }
+
+                error = xfs_btree_increment(cur, 0, &has_record);
+        }
+        return error;
+}
+
+/* Is there an inode record covering a given extent? */
+int
+xfs_ialloc_has_inodes_at_extent(
+        struct xfs_btree_cur    *cur,
+        xfs_agblock_t           bno,
+        xfs_extlen_t            len,
+        bool                    *exists)
+{
+        xfs_agino_t             low;
+        xfs_agino_t             high;
+
+        low = XFS_OFFBNO_TO_AGINO(cur->bc_mp, bno, 0);
+        high = XFS_OFFBNO_TO_AGINO(cur->bc_mp, bno + len, 0) - 1;
+
+        return xfs_ialloc_has_inode_record(cur, low, high, exists);
+}
+
+struct xfs_ialloc_count_inodes {
+        xfs_agino_t                     count;
+        xfs_agino_t                     freecount;
+};
+
+/* Record inode counts across all inobt records. */
+STATIC int
+xfs_ialloc_count_inodes_rec(
+        struct xfs_btree_cur            *cur,
+        union xfs_btree_rec             *rec,
+        void                            *priv)
+{
+        struct xfs_inobt_rec_incore     irec;
+        struct xfs_ialloc_count_inodes  *ci = priv;
+
+        xfs_inobt_btrec_to_irec(cur->bc_mp, rec, &irec);
+        ci->count += irec.ir_count;
+        ci->freecount += irec.ir_freecount;
+
+        return 0;
+}
+
+/* Count allocated and free inodes under an inobt. */
+int
+xfs_ialloc_count_inodes(
+        struct xfs_btree_cur            *cur,
+        xfs_agino_t                     *count,
+        xfs_agino_t                     *freecount)
+{
+        struct xfs_ialloc_count_inodes  ci = {0};
+        int                             error;
+
+        ASSERT(cur->bc_btnum == XFS_BTNUM_INO);
+        error = xfs_btree_query_all(cur, xfs_ialloc_count_inodes_rec, &ci);
+        if (error)
+                return error;
+
+        *count = ci.count;
+        *freecount = ci.freecount;
+        return 0;
+}
diff --git a/fs/xfs/libxfs/xfs_ialloc.h b/fs/xfs/libxfs/xfs_ialloc.h
index 66a8de0b1caa..c5402bb4ce0c 100644
--- a/fs/xfs/libxfs/xfs_ialloc.h
+++ b/fs/xfs/libxfs/xfs_ialloc.h
@@ -170,6 +170,12 @@ int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
 union xfs_btree_rec;
 void xfs_inobt_btrec_to_irec(struct xfs_mount *mp, union xfs_btree_rec *rec,
                 struct xfs_inobt_rec_incore *irec);
+int xfs_ialloc_has_inodes_at_extent(struct xfs_btree_cur *cur,
+                xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
+int xfs_ialloc_has_inode_record(struct xfs_btree_cur *cur, xfs_agino_t low,
+                xfs_agino_t high, bool *exists);
+int xfs_ialloc_count_inodes(struct xfs_btree_cur *cur, xfs_agino_t *count,
+                xfs_agino_t *freecount);
 
 int xfs_ialloc_cluster_alignment(struct xfs_mount *mp);
 void xfs_ialloc_agino_range(struct xfs_mount *mp, xfs_agnumber_t agno,