make checkpointing more robust

As long as the root inode hasn't changed phase, we keep
looking for things to do.
If things got confused, this could livelock, which would be bad...

diff --git a/checkpoint.c b/checkpoint.c
index e0d5e93cb31483efdb355a69919560c181533e76..b6f9061c3c7eec88c5f3d0c92a7f489ae0bd8661 100644 (file)
--- a/checkpoint.c
+++ b/checkpoint.c
@@ -353,7 +353,6 @@ static void do_checkpoint(void *data)
        struct fs *fs = data;
        int oldphase = !fs->phase; /*FIXME could there be a race getting this?*/
        struct block *b;
-       int cnt = 0;
 #ifdef DUMP
        dfs = fs;
 #endif
@@ -361,6 +360,7 @@ static void do_checkpoint(void *data)
        dprintk("Start Checkpoint\n");
        if (lafs_trace)
                lafs_dump_tree();
+ again:
        while ((b = lafs_get_flushable(fs, oldphase)) != NULL) {
                int unlock = 1;
                dprintk("Checkpoint Block %s\n", strblk(b));
@@ -402,38 +402,17 @@ static void do_checkpoint(void *data)
                        lafs_iounlock_block(b, 0);
 
                putref(b, MKREF(leaf));
-               if (list_empty(&fs->phase_leafs[oldphase])) {
-                       lafs_cluster_flush(fs, 0);
-                       lafs_cluster_wait_all(fs);
-                       lafs_clusters_done(fs);
-               }
-               cnt++;
        }
-       lafs_clusters_done(fs);
-
        if (test_bit(B_Pinned, &LAFSI(fs->ss[0].root)->iblock->b.flags) &&
            !!test_bit(B_Phase1, &LAFSI(fs->ss[0].root)->iblock->b.flags)
            != fs->phase) {
-               struct indexblock *ib = LAFSI(fs->ss[0].root)->iblock;
-               struct block *cb;
-               printk("ROOT has not changed phase!! \n");
-               lafs_dump_tree();
-               cb = &ib->b;
-               printk("Root %s Block still old: %s\n",
-                      test_bit(B_Index, &cb->flags) ? "Index" : "Data",
-                      strblk(cb));
-
-               list_for_each_entry(cb, &ib->children, siblings)
-                       if (test_bit(B_Pinned, &cb->flags)) {
-                               int pp = !!test_bit(B_Phase1, &cb->flags);
-                               if (pp != fs->phase)
-                                       printk("%s Block still old: %s\n",
-                                              test_bit(B_Index, &cb->flags)
-                                              ? "Index" : "Data",
-                                              strblk(cb));
-                       }
-               BUG();
+               BUG_ON(list_empty(&fs->wc[0].clhead));
+               lafs_cluster_flush(fs, 0);
+               lafs_cluster_wait_all(fs);
+               lafs_clusters_done(fs);
+               goto again;
        }
+       lafs_clusters_done(fs);
 }
 
 static void finish_checkpoint(struct fs *fs, int youth)