bcachefs: Improvements to writing alloc info

Now that we've got transactional alloc info updates (and have for
awhile), we don't need to write it out on shutdown, and we don't need to
write it out on startup except when GC found errors - this is a big
improvement to mount/unmount performance.

This patch also fixes a few bugs where we weren't writing out alloc
info (on new filesystems, and new devices) and should have been.

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

1 files changed, 29 insertions, 9 deletions

diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index 6e829bf0a31f..d70fa968db50 100644
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -845,9 +845,11 @@ static int verify_superblock_clean(struct bch_fs *c,
 	}
 
 	mustfix_fsck_err_on(j->read_clock != clean->read_clock, c,
-			"superblock read clock doesn't match journal after clean shutdown");
+			"superblock read clock %u doesn't match journal %u after clean shutdown",
+			clean->read_clock, j->read_clock);
 	mustfix_fsck_err_on(j->write_clock != clean->write_clock, c,
-			"superblock read clock doesn't match journal after clean shutdown");
+			"superblock write clock %u doesn't match journal %u after clean shutdown",
+			clean->write_clock, j->write_clock);
 
 	for (i = 0; i < BTREE_ID_NR; i++) {
 		char buf1[200], buf2[200];
@@ -961,7 +963,7 @@ int bch2_fs_recovery(struct bch_fs *c)
 	const char *err = "cannot allocate memory";
 	struct bch_sb_field_clean *clean = NULL;
 	u64 journal_seq;
-	bool wrote = false, write_sb = false;
+	bool write_sb = false, need_write_alloc = false;
 	int ret;
 
 	if (c->sb.clean)
@@ -1090,8 +1092,10 @@ int bch2_fs_recovery(struct bch_fs *c)
 		bch_info(c, "starting metadata mark and sweep");
 		err = "error in mark and sweep";
 		ret = bch2_gc(c, &c->journal_keys, true, true);
-		if (ret)
+		if (ret < 0)
 			goto err;
+		if (ret)
+			need_write_alloc = true;
 		bch_verbose(c, "mark and sweep done");
 	}
 
@@ -1101,8 +1105,10 @@ int bch2_fs_recovery(struct bch_fs *c)
 		bch_info(c, "starting mark and sweep");
 		err = "error in mark and sweep";
 		ret = bch2_gc(c, &c->journal_keys, true, false);
-		if (ret)
+		if (ret < 0)
 			goto err;
+		if (ret)
+			need_write_alloc = true;
 		bch_verbose(c, "mark and sweep done");
 	}
 
@@ -1126,7 +1132,7 @@ int bch2_fs_recovery(struct bch_fs *c)
 		goto err;
 	bch_verbose(c, "journal replay done");
 
-	if (!c->opts.nochanges) {
+	if (need_write_alloc && !c->opts.nochanges) {
 		/*
 		 * note that even when filesystem was clean there might be work
 		 * to do here, if we ran gc (because of fsck) which recalculated
@@ -1134,8 +1140,8 @@ int bch2_fs_recovery(struct bch_fs *c)
 		 */
 		bch_verbose(c, "writing allocation info");
 		err = "error writing out alloc info";
-		ret = bch2_stripes_write(c, BTREE_INSERT_LAZY_RW, &wrote) ?:
-			bch2_alloc_write(c, BTREE_INSERT_LAZY_RW, &wrote);
+		ret = bch2_stripes_write(c, BTREE_INSERT_LAZY_RW) ?:
+			bch2_alloc_write(c, BTREE_INSERT_LAZY_RW);
 		if (ret) {
 			bch_err(c, "error writing alloc info");
 			goto err;
@@ -1281,6 +1287,20 @@ int bch2_fs_initialize(struct bch_fs *c)
 	bch2_fs_journal_start(&c->journal, 1, &journal);
 	bch2_journal_set_replay_done(&c->journal);
 
+	err = "error going read-write";
+	ret = bch2_fs_read_write_early(c);
+	if (ret)
+		goto err;
+
+	/*
+	 * Write out the superblock and journal buckets, now that we can do
+	 * btree updates
+	 */
+	err = "error writing alloc info";
+	ret = bch2_alloc_write(c, 0);
+	if (ret)
+		goto err;
+
 	bch2_inode_init(c, &root_inode, 0, 0,
 			S_IFDIR|S_IRWXU|S_IRUGO|S_IXUGO, 0, NULL);
 	root_inode.bi_inum = BCACHEFS_ROOT_INO;
@@ -1289,7 +1309,7 @@ int bch2_fs_initialize(struct bch_fs *c)
 	err = "error creating root directory";
 	ret = bch2_btree_insert(c, BTREE_ID_INODES,
 				&packed_inode.inode.k_i,
-				NULL, NULL, BTREE_INSERT_LAZY_RW);
+				NULL, NULL, 0);
 	if (ret)
 		goto err;