xfs_repair: add AG btree rmaps into the filesystem after syncing sb

In rmap_store_ag_btree_rec(), we try to reserve 16 blocks to handle
adding all the AG btree rmaps to the rmap record.  Unfortunately, at
that point in phase5 we haven't yet reinitialied sb_fdblocks, so
reserving blocks can fail if repair reconstructed the primary sb from a
secondary sb.  Even if the function succeeds, this still leads to
incorrect fdblocks because phase 5 resets sb_fdblocks after running the
rmap transactions.

To avoid all this, move the rmap_store_ag_btree_rec call to after the sb
has been reset.  xfs/350 was helpful in finding cases where xfs_repair
errored out while repairing the filesystem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/repair/phase5.c b/repair/phase5.c
index 2e18cc6947708818a79f2bac625d49f398e6e91c..7f7d3d180a454267190920bca167191c57fe29db 100644 (file)
--- a/repair/phase5.c
+++ b/repair/phase5.c
@@ -2233,7 +2233,6 @@ phase5_func(
 #endif
        xfs_agblock_t   num_extents;
        struct agi_stat agi_stat = {0,};
-       int             error;
 
        if (verbose)
                do_log(_("        - agno = %d\n"), agno);
@@ -2426,14 +2425,6 @@ phase5_func(
                        finish_cursor(&fino_btree_curs);
                finish_cursor(&bcnt_btree_curs);
 
-               /*
-                * Put the per-AG btree rmap data into the rmapbt
-                */
-               error = rmap_store_ag_btree_rec(mp, agno);
-               if (error)
-                       do_error(
-_("unable to add AG %u reverse-mapping data to btree.\n"), agno);
-
                /*
                 * release the incore per-AG bno/bcnt trees so
                 * the extent nodes can be recycled
@@ -2561,6 +2552,21 @@ phase5(xfs_mount_t *mp)
         */
        sync_sb(mp);
 
+       /*
+        * Put the per-AG btree rmap data into the rmapbt now that we've reset
+        * the superblock counters.
+        */
+       for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
+               error = rmap_store_ag_btree_rec(mp, agno);
+               if (error)
+                       do_error(
+_("unable to add AG %u reverse-mapping data to btree.\n"), agno);
+       }
+
+       /*
+        * Put blocks that were unnecessarily reserved for btree
+        * reconstruction back into the filesystem free space data.
+        */
        error = inject_lost_blocks(mp, lost_fsb);
        if (error)
                do_error(_("Unable to reinsert lost blocks into filesystem.\n"));