xfs: walk the rt reverse mapping tree when rebuilding rmap

When we're rebuilding the data device rmap, if we encounter an "rmap"
format fork, we have to walk the (realtime) rmap btree inode to build
the appropriate mappings.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/xfs/scrub/rmap_repair.c b/fs/xfs/scrub/rmap_repair.c
index a0a227d183d28d1118db4dd732b71467e4c139ad..e1a4ea48cc5a8cd83daa51b91ecc4b27ce9cdfe8 100644 (file)
--- a/fs/xfs/scrub/rmap_repair.c
+++ b/fs/xfs/scrub/rmap_repair.c
@@ -31,6 +31,8 @@
 #include "xfs_refcount.h"
 #include "xfs_refcount_btree.h"
 #include "xfs_ag.h"
+#include "xfs_rtrmap_btree.h"
+#include "xfs_rtgroup.h"
 #include "scrub/xfs_scrub.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
@@ -499,6 +501,41 @@ xrep_rmap_scan_iext(
        return xrep_rmap_stash_accumulated(rf);
 }
 
+static int
+xrep_rmap_scan_rtrmapbt(
+       struct xrep_rmap_ifork  *rf,
+       struct xfs_inode        *ip)
+{
+       struct xfs_scrub        *sc = rf->rr->sc;
+       struct xfs_rtgroup      *rtg = NULL;
+       struct xfs_btree_cur    *cur;
+       int                     error;
+
+       if (rf->whichfork != XFS_DATA_FORK)
+               return -EFSCORRUPTED;
+
+       while ((rtg = xfs_rtgroup_next(sc->mp, rtg))) {
+               if (ip == rtg->rtg_inodes[XFS_RTGI_RMAP]) {
+                       cur = xfs_rtrmapbt_init_cursor(sc->tp, rtg);
+                       error = xrep_rmap_scan_iroot_btree(rf, cur);
+                       xfs_btree_del_cursor(cur, error);
+                       xfs_rtgroup_rele(rtg);
+                       return error;
+               }
+       }
+
+       /*
+        * We shouldn't find an rmap format inode that isn't associated with
+        * an rtgroup and has ondisk blocks allocated to it.
+        */
+       if (ip->i_nblocks) {
+               ASSERT(0);
+               return -EFSCORRUPTED;
+       }
+
+       return 0;
+}
+
 /* Find all the extents from a given AG in an inode fork. */
 STATIC int
 xrep_rmap_scan_ifork(
@@ -528,6 +565,8 @@ xrep_rmap_scan_ifork(
                error = xrep_rmap_scan_bmbt(&rf, ip, &mappings_done);
                if (error || mappings_done)
                        return error;
+       } else if (ifp->if_format == XFS_DINODE_FMT_RMAP) {
+               return xrep_rmap_scan_rtrmapbt(&rf, ip);
        } else if (ifp->if_format != XFS_DINODE_FMT_EXTENTS) {
                return 0;
        }