bcachefs: Go RW before check_alloc_info()

It's possible to do btree updates before going RW by adding them to the
list of updates for journal replay to do, but this is limited by what
fits in RAM. This patch switches the second alloc info phase to run
after going RW - btree_gc has already ensured the alloc btree itself is
correct - and tweaks the allocation path to deal with the potential
small inconsistencies.

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

1 files changed, 20 insertions, 12 deletions

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 1db0b6253661..f75d05beaf31 100644
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -583,6 +583,7 @@ static int bch2_bucket_do_index(struct btree_trans *trans,
 		goto err;
 
 	if (ca->mi.freespace_initialized &&
+	    test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags) &&
 	    bch2_trans_inconsistent_on(old.k->type != old_type, trans,
 			"incorrect key when %s %s btree (got %s should be %s)\n"
 			"  for %s",
@@ -1028,21 +1029,28 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
 		goto write;
 	}
 
-	if (bch2_trans_inconsistent_on(a->v.journal_seq > c->journal.flushed_seq_ondisk, trans,
-			"clearing need_discard but journal_seq %llu > flushed_seq %llu\n"
-			"%s",
-			a->v.journal_seq,
-			c->journal.flushed_seq_ondisk,
-			(bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
-		ret = -EIO;
+	if (a->v.journal_seq > c->journal.flushed_seq_ondisk) {
+		if (test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags)) {
+			bch2_trans_inconsistent(trans,
+				"clearing need_discard but journal_seq %llu > flushed_seq %llu\n"
+				"%s",
+				a->v.journal_seq,
+				c->journal.flushed_seq_ondisk,
+				(bch2_bkey_val_to_text(&buf, c, k), buf.buf));
+			ret = -EIO;
+		}
 		goto out;
 	}
 
-	if (bch2_trans_inconsistent_on(a->v.data_type != BCH_DATA_need_discard, trans,
-			"bucket incorrectly set in need_discard btree\n"
-			"%s",
-			(bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
-		ret = -EIO;
+	if (a->v.data_type != BCH_DATA_need_discard) {
+		if (test_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags)) {
+			bch2_trans_inconsistent(trans,
+				"bucket incorrectly set in need_discard btree\n"
+				"%s",
+				(bch2_bkey_val_to_text(&buf, c, k), buf.buf));
+			ret = -EIO;
+		}
+
 		goto out;
 	}