bcachefs: Delete some obsolete journal_seq_blacklist code

Since metadata version bcachefs_metadata_version_btree_ptr_sectors_written,
we haven't needed the journal seq blacklist mechanism for ignoring
blacklisted btree node writes - we now only need it for ignoring journal
entries that were written after the newest flush journal entry, and then
we only need to keep those blacklist entries around until journal replay
is finished.

That means we can delete the code for scanning btree nodes to GC
journal_seq_blacklist entries.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/bcachefs.h

@@ -750,7 +750,6 @@ struct bch_fs {
 	/* JOURNAL SEQ BLACKLIST */
 	struct journal_seq_blacklist_table *
 				journal_seq_blacklist_table;
-	struct work_struct	journal_seq_blacklist_gc_work;
 
 	/* ALLOCATOR */
 	spinlock_t		freelist_lock;

fs/bcachefs/journal_seq_blacklist.c

@@ -235,81 +235,3 @@ const struct bch_sb_field_ops bch_sb_field_ops_journal_seq_blacklist = {
 	.validate	= bch2_sb_journal_seq_blacklist_validate,
 	.to_text	= bch2_sb_journal_seq_blacklist_to_text
 };
-
-void bch2_blacklist_entries_gc(struct work_struct *work)
-{
-	struct bch_fs *c = container_of(work, struct bch_fs,
-					journal_seq_blacklist_gc_work);
-	struct journal_seq_blacklist_table *t;
-	struct bch_sb_field_journal_seq_blacklist *bl;
-	struct journal_seq_blacklist_entry *src, *dst;
-	struct btree_trans trans;
-	unsigned i, nr, new_nr;
-	int ret;
-
-	bch2_trans_init(&trans, c, 0, 0);
-
-	for (i = 0; i < BTREE_ID_NR; i++) {
-		struct btree_iter iter;
-		struct btree *b;
-
-		bch2_trans_node_iter_init(&trans, &iter, i, POS_MIN,
-					  0, 0, BTREE_ITER_PREFETCH);
-retry:
-		bch2_trans_begin(&trans);
-
-		b = bch2_btree_iter_peek_node(&iter);
-
-		while (!(ret = PTR_ERR_OR_ZERO(b)) &&
-		       b &&
-		       !test_bit(BCH_FS_STOPPING, &c->flags))
-			b = bch2_btree_iter_next_node(&iter);
-
-		if (ret == -EINTR)
-			goto retry;
-
-		bch2_trans_iter_exit(&trans, &iter);
-	}
-
-	bch2_trans_exit(&trans);
-	if (ret)
-		return;
-
-	mutex_lock(&c->sb_lock);
-	bl = bch2_sb_get_journal_seq_blacklist(c->disk_sb.sb);
-	if (!bl)
-		goto out;
-
-	nr = blacklist_nr_entries(bl);
-	dst = bl->start;
-
-	t = c->journal_seq_blacklist_table;
-	BUG_ON(nr != t->nr);
-
-	for (src = bl->start, i = eytzinger0_first(t->nr);
-	     src < bl->start + nr;
-	     src++, i = eytzinger0_next(i, nr)) {
-		BUG_ON(t->entries[i].start	!= le64_to_cpu(src->start));
-		BUG_ON(t->entries[i].end	!= le64_to_cpu(src->end));
-
-		if (t->entries[i].dirty)
-			*dst++ = *src;
-	}
-
-	new_nr = dst - bl->start;
-
-	bch_info(c, "nr blacklist entries was %u, now %u", nr, new_nr);
-
-	if (new_nr != nr) {
-		bl = bch2_sb_resize_journal_seq_blacklist(&c->disk_sb,
-				new_nr ? sb_blacklist_u64s(new_nr) : 0);
-		BUG_ON(new_nr && !bl);
-
-		if (!new_nr)
-			c->disk_sb.sb->features[0] &= cpu_to_le64(~(1ULL << BCH_FEATURE_journal_seq_blacklist_v3));
-
-		bch2_write_super(c);
-	}
-out:
-	mutex_unlock(&c->sb_lock);
-}

fs/bcachefs/journal_seq_blacklist.h

@@ -17,6 +17,4 @@ int bch2_blacklist_table_initialize(struct bch_fs *);
 
 extern const struct bch_sb_field_ops bch_sb_field_ops_journal_seq_blacklist;
 
-void bch2_blacklist_entries_gc(struct work_struct *);
-
 #endif /* _BCACHEFS_JOURNAL_SEQ_BLACKLIST_H */

fs/bcachefs/recovery.c

@@ -1162,16 +1162,6 @@ int bch2_fs_recovery(struct bch_fs *c)
 	if (ret)
 		goto err;
 
-	/*
-	 * After an unclean shutdown, skip then next few journal sequence
-	 * numbers as they may have been referenced by btree writes that
-	 * happened before their corresponding journal writes - those btree
-	 * writes need to be ignored, by skipping and blacklisting the next few
-	 * journal sequence numbers:
-	 */
-	if (!c->sb.clean)
-		journal_seq += 8;
-
 	if (blacklist_seq != journal_seq) {
 		ret = bch2_journal_seq_blacklist_add(c,
 					blacklist_seq, journal_seq);
@@ -1309,7 +1299,8 @@ int bch2_fs_recovery(struct bch_fs *c)
 	}
 
 	if (!(c->sb.compat & (1ULL << BCH_COMPAT_extents_above_btree_updates_done)) ||
-	    !(c->sb.compat & (1ULL << BCH_COMPAT_bformat_overflow_done))) {
+	    !(c->sb.compat & (1ULL << BCH_COMPAT_bformat_overflow_done)) ||
+	    le16_to_cpu(c->sb.version_min) < bcachefs_metadata_version_btree_ptr_sectors_written) {
 		struct bch_move_stats stats;
 
 		bch_move_stats_init(&stats, "recovery");
@@ -1326,6 +1317,15 @@ int bch2_fs_recovery(struct bch_fs *c)
 	}
 
 	mutex_lock(&c->sb_lock);
+	/*
+	 * With journal replay done, we can clear the journal seq blacklist
+	 * table:
+	 */
+	BUG_ON(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags));
+	BUG_ON(le16_to_cpu(c->sb.version_min) < bcachefs_metadata_version_btree_ptr_sectors_written);
+
+	bch2_sb_resize_journal_seq_blacklist(&c->disk_sb, 0);
+
 	if (c->opts.version_upgrade) {
 		c->disk_sb.sb->version = cpu_to_le16(bcachefs_metadata_version_current);
 		c->disk_sb.sb->features[0] |= cpu_to_le64(BCH_SB_FEATURES_ALL);
@@ -1349,10 +1349,6 @@ int bch2_fs_recovery(struct bch_fs *c)
 		bch2_write_super(c);
 	mutex_unlock(&c->sb_lock);
 
-	if (c->journal_seq_blacklist_table &&
-	    c->journal_seq_blacklist_table->nr > 128)
-		queue_work(system_long_wq, &c->journal_seq_blacklist_gc_work);
-
 	ret = 0;
 out:
 	set_bit(BCH_FS_FSCK_DONE, &c->flags);

fs/bcachefs/super.c

@@ -535,8 +535,6 @@ void __bch2_fs_stop(struct bch_fs *c)
 
 	set_bit(BCH_FS_STOPPING, &c->flags);
 
-	cancel_work_sync(&c->journal_seq_blacklist_gc_work);
-
 	down_write(&c->state_lock);
 	bch2_fs_read_only(c);
 	up_write(&c->state_lock);
@@ -700,9 +698,6 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 
 	spin_lock_init(&c->btree_write_error_lock);
 
-	INIT_WORK(&c->journal_seq_blacklist_gc_work,
-		  bch2_blacklist_entries_gc);
-
 	INIT_LIST_HEAD(&c->journal_entries);
 	INIT_LIST_HEAD(&c->journal_iters);