xfs: pass perags around in fsmap data dev functions

Source kernel commit: 58d43a7e3263766ade4974c86118e6b5737ea259

Needs a [from, to] ranged AG walk, and the perag to be stuffed into
the info structure for callouts to use.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_ag.h b/libxfs/xfs_ag.h
index 052f5ff4850436a909bbb675b194f9d82a99499b..fa58a45fbe9837a6529e2334c5c89b294960bbfe 100644 (file)
--- a/libxfs/xfs_ag.h
+++ b/libxfs/xfs_ag.h
@@ -116,14 +116,25 @@ void      xfs_perag_put(struct xfs_perag *pag);
 
 /*
  * Perag iteration APIs
+ *
+ * XXX: for_each_perag_range() usage really needs an iterator to clean up when
+ * we terminate at end_agno because we may have taken a reference to the perag
+ * beyond end_agno. Right now callers have to be careful to catch and clean that
+ * up themselves. This is not necessary for the callers of for_each_perag() and
+ * for_each_perag_from() because they terminate at sb_agcount where there are
+ * no perag structures in tree beyond end_agno.
  */
-#define for_each_perag_from(mp, next_agno, pag) \
+#define for_each_perag_range(mp, next_agno, end_agno, pag) \
        for ((pag) = xfs_perag_get((mp), (next_agno)); \
-               (pag) != NULL; \
+               (pag) != NULL && (next_agno) <= (end_agno); \
                (next_agno) = (pag)->pag_agno + 1, \
                xfs_perag_put(pag), \
                (pag) = xfs_perag_get((mp), (next_agno)))
 
+#define for_each_perag_from(mp, next_agno, pag) \
+       for_each_perag_range((mp), (next_agno), (mp)->m_sb.sb_agcount, (pag))
+
+
 #define for_each_perag(mp, agno, pag) \
        (agno) = 0; \
        for_each_perag_from((mp), (agno), (pag))