bcachefs: Track nr_inodes with the key marking machinery

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

fs/bcachefs/bcachefs.h

@@ -721,9 +721,6 @@ struct bch_fs {
 	struct mutex		fsck_error_lock;
 	bool			fsck_alloc_err;
 
-	/* FILESYSTEM */
-	atomic_long_t		nr_inodes;
-
 	/* QUOTAS */
 	struct bch_memquota_type quotas[QTYP_NR];
 

fs/bcachefs/btree_gc.c

@@ -685,6 +685,7 @@ static void bch2_gc_done(struct bch_fs *c, bool initial)
 		for (b = 0; b < BCH_DATA_NR; b++)
 			copy_fs_field(buckets[b],
 				      "buckets[%s]", bch2_data_types[b]);
+		copy_fs_field(nr_inodes, "nr_inodes");
 
 		for_each_possible_cpu(cpu) {
 			p = per_cpu_ptr(c->usage[0], cpu);

fs/bcachefs/btree_types.h

@@ -439,6 +439,7 @@ static inline bool btree_node_type_needs_gc(enum btree_node_type type)
 	switch (type) {
 	case BKEY_TYPE_BTREE:
 	case BKEY_TYPE_EXTENTS:
+	case BKEY_TYPE_INODES:
 	case BKEY_TYPE_EC:
 		return true;
 	default:

fs/bcachefs/buckets.c

@@ -862,6 +862,12 @@ static int __bch2_mark_key(struct bch_fs *c, struct bkey_s_c k,
 		ret = bch2_mark_stripe(c, k, inserting,
 				       stats, journal_seq, flags, gc);
 		break;
+	case KEY_TYPE_alloc:
+		if (inserting)
+			stats->nr_inodes++;
+		else
+			stats->nr_inodes--;
+		break;
 	case KEY_TYPE_reservation: {
 		unsigned replicas = bkey_s_c_to_reservation(k).v->nr_replicas;
 

fs/bcachefs/buckets_types.h

@@ -73,6 +73,8 @@ struct bch_fs_usage {
 
 	u64			buckets[BCH_DATA_NR];
 
+	u64			nr_inodes;
+
 	/* fields starting here aren't touched by gc: */
 	u64			online_reserved;
 	u64			available_cache;

fs/bcachefs/fs.c

@@ -400,8 +400,6 @@ __bch2_create(struct mnt_idmap *idmap,
 	if (unlikely(ret))
 		goto err_trans;
 
-	atomic_long_inc(&c->nr_inodes);
-
 	if (!tmpfile) {
 		bch2_inode_update_after_write(c, dir, &dir_u,
 					      ATTR_MTIME|ATTR_CTIME);
@@ -1418,9 +1416,6 @@ static void bch2_evict_inode(struct inode *vinode)
 		bch2_quota_acct(c, inode->ei_qid, Q_INO, -1,
 				KEY_TYPE_QUOTA_WARN);
 		bch2_inode_rm(c, inode->v.i_ino);
-
-		WARN_ONCE(atomic_long_dec_return(&c->nr_inodes) < 0,
-			  "nr_inodes < 0");
 	}
 }
 
@@ -1439,7 +1434,7 @@ static int bch2_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_blocks	= (c->capacity - hidden_metadata) >> shift;
 	buf->f_bfree	= (c->capacity - bch2_fs_sectors_used(c, usage)) >> shift;
 	buf->f_bavail	= buf->f_bfree;
-	buf->f_files	= atomic_long_read(&c->nr_inodes);
+	buf->f_files	= usage.nr_inodes;
 	buf->f_ffree	= U64_MAX;
 
 	fsid = le64_to_cpup((void *) c->sb.user_uuid.b) ^

fs/bcachefs/fsck.c

@@ -1314,9 +1314,6 @@ peek_nlinks:	link = genradix_iter_peek(&nlinks_iter, links);
 			BUG_ON(ret == -EINTR);
 			if (ret)
 				break;
-
-			if (link->count)
-				atomic_long_inc(&c->nr_inodes);
 		} else {
 			/* Should have been caught by dirents pass: */
 			need_fsck_err_on(link->count, c,
@@ -1380,7 +1377,6 @@ static int check_inodes_fast(struct bch_fs *c)
 	struct btree_iter iter;
 	struct bkey_s_c k;
 	struct bkey_s_c_inode inode;
-	unsigned long nr_inodes = 0;
 	int ret = 0;
 
 	for_each_btree_key(&iter, c, BTREE_ID_INODES, POS_MIN, 0, k) {
@@ -1389,9 +1385,6 @@ static int check_inodes_fast(struct bch_fs *c)
 
 		inode = bkey_s_c_to_inode(k);
 
-		if (!(inode.v->bi_flags & BCH_INODE_UNLINKED))
-			nr_inodes++;
-
 		if (inode.v->bi_flags &
 		    (BCH_INODE_I_SIZE_DIRTY|
 		     BCH_INODE_I_SECTORS_DIRTY|
@@ -1405,7 +1398,6 @@ static int check_inodes_fast(struct bch_fs *c)
 				break;
 		}
 	}
-	atomic_long_set(&c->nr_inodes, nr_inodes);
 fsck_err:
 	return bch2_btree_iter_unlock(&iter) ?: ret;
 }

fs/bcachefs/recovery.c

@@ -375,8 +375,6 @@ int bch2_fs_initialize(struct bch_fs *c)
 	if (ret)
 		goto err;
 
-	atomic_long_set(&c->nr_inodes, 2);
-
 	if (enabled_qtypes(c)) {
 		ret = bch2_fs_quota_read(c);
 		if (ret)