bcachefs: New and improved topology repair code

This splits out btree topology repair into a separate pass, and makes
some improvements:
 - When we have to pick which of two overlapping nodes to drop keys
   from, we use the btree node header sequence number to preserve the
   newer node

 - the gc code has been changed so that it doesn't bail out if we're
   continuing/ignoring on fsck error - this way the dump tool can skip
   running the repair pass but still walk all reachable metadata

 - add a new superblock flag indicating when a filesystem is known to
   have btree topology issues, and the topology repair pass should be
   run

 - changing the start/end of a node might mean keys in that node have to
   be deleted: this patch handles that better by splitting it out into a
   separate function and running it explicitly in the topology repair
   code, previously those keys were only being dropped when the btree
   node was read in.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index fe6886e42216..a9ccd14effe7 100644
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -1241,8 +1241,9 @@ use_clean:
 
 	if (c->opts.fsck &&
 	    !test_bit(BCH_FS_ERROR, &c->flags) &&
-	    BCH_SB_HAS_ERRORS(c->disk_sb.sb)) {
+	    !test_bit(BCH_FS_ERRORS_NOT_FIXED, &c->flags)) {
 		SET_BCH_SB_HAS_ERRORS(c->disk_sb.sb, 0);
+		SET_BCH_SB_HAS_TOPOLOGY_ERRORS(c->disk_sb.sb, 0);
 		write_sb = true;
 	}