btrfs: transaction: Cleanup unused TRANS_STATE_BLOCKED

The state was introduced in commit 4a9d8bd ("Btrfs: make the state
of the transaction more readable"), then in commit 302167c
("btrfs: don't end the transaction for delayed refs in throttle") the
state is completely removed.

So we can just clean up the state since it's only compared but never
set.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -1741,7 +1741,7 @@ static int transaction_kthread(void *arg)
 		}
 
 		now = ktime_get_seconds();
-		if (cur->state < TRANS_STATE_BLOCKED &&
+		if (cur->state < TRANS_STATE_COMMIT_START &&
 		    !test_bit(BTRFS_FS_NEED_ASYNC_COMMIT, &fs_info->flags) &&
 		    (now < cur->start_time ||
 		     now - cur->start_time < fs_info->commit_interval)) {

fs/btrfs/transaction.c

@@ -97,7 +97,6 @@
  */
 static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
 	[TRANS_STATE_RUNNING]		= 0U,
-	[TRANS_STATE_BLOCKED]		=  __TRANS_START,
 	[TRANS_STATE_COMMIT_START]	= (__TRANS_START | __TRANS_ATTACH),
 	[TRANS_STATE_COMMIT_DOING]	= (__TRANS_START |
 					   __TRANS_ATTACH |
@@ -454,7 +453,7 @@ int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 
 static inline int is_transaction_blocked(struct btrfs_transaction *trans)
 {
-	return (trans->state >= TRANS_STATE_BLOCKED &&
+	return (trans->state >= TRANS_STATE_COMMIT_START &&
 		trans->state < TRANS_STATE_UNBLOCKED &&
 		!trans->aborted);
 }
@@ -641,7 +640,7 @@ start_transaction(struct btrfs_root *root, unsigned int num_items,
 	INIT_LIST_HEAD(&h->new_bgs);
 
 	smp_mb();
-	if (cur_trans->state >= TRANS_STATE_BLOCKED &&
+	if (cur_trans->state >= TRANS_STATE_COMMIT_START &&
 	    may_wait_transaction(fs_info, type)) {
 		current->journal_info = h;
 		btrfs_commit_transaction(h);
@@ -869,7 +868,7 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans)
 	struct btrfs_transaction *cur_trans = trans->transaction;
 
 	smp_mb();
-	if (cur_trans->state >= TRANS_STATE_BLOCKED ||
+	if (cur_trans->state >= TRANS_STATE_COMMIT_START ||
 	    cur_trans->delayed_refs.flushing)
 		return 1;
 
@@ -902,7 +901,6 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 {
 	struct btrfs_fs_info *info = trans->fs_info;
 	struct btrfs_transaction *cur_trans = trans->transaction;
-	int lock = (trans->type != TRANS_JOIN_NOLOCK);
 	int err = 0;
 
 	if (refcount_read(&trans->use_count) > 1) {
@@ -918,13 +916,6 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
 
 	btrfs_trans_release_chunk_metadata(trans);
 
-	if (lock && READ_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
-		if (throttle)
-			return btrfs_commit_transaction(trans);
-		else
-			wake_up_process(info->transaction_kthread);
-	}
-
 	if (trans->type & __TRANS_FREEZABLE)
 		sb_end_intwrite(info->sb);
 

fs/btrfs/transaction.h

@@ -13,7 +13,6 @@
 
 enum btrfs_trans_state {
 	TRANS_STATE_RUNNING,
-	TRANS_STATE_BLOCKED,
 	TRANS_STATE_COMMIT_START,
 	TRANS_STATE_COMMIT_DOING,
 	TRANS_STATE_UNBLOCKED,