[PATCH 2/4] Btrfs: track transaction aborted across the fs_info

[Josef Bacik <josef@redhat.com>]

If we abort a transaction during the commit phase we can have people who
start new transactions because we nave no way of signaling to them that
something went wrong.  So add a trans_aborted flag to the fs_info so the
start transaction code can be notified that the last transaction was aborted
and it needs to return an error.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
---
 fs/btrfs/ctree.h       |    1 +
 fs/btrfs/super.c       |    1 +
 fs/btrfs/transaction.c |   14 ++++++++++++++
 3 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5f2c6d1..34549ca 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1213,6 +1213,7 @@ struct btrfs_fs_info {
 	int log_root_recovering;
 	int enospc_unlink;
 	int trans_no_join;
+	int trans_aborted;
 
 	u64 total_pinned;
 
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 85cef50..e0abe7f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -226,6 +226,7 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
 		return;
 	}
 	trans->transaction->aborted = errno;
+	root->fs_info->trans_aborted = errno;
 	__btrfs_std_error(root->fs_info, function, line, errno, NULL);
 }
 /*
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 4e6f63e..e292b83 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -77,13 +77,21 @@ loop:
 		if (cur_trans->aborted) {
 			spin_unlock(&root->fs_info->trans_lock);
 			return cur_trans->aborted;
+		} else if (root->fs_info->trans_aborted) {
+			WARN_ON(1);
+			spin_unlock(&root->fs_info->trans_lock);
+			return root->fs_info->trans_aborted;
 		}
 		atomic_inc(&cur_trans->use_count);
 		atomic_inc(&cur_trans->num_writers);
 		cur_trans->num_joined++;
 		spin_unlock(&root->fs_info->trans_lock);
 		return 0;
+	} else if (root->fs_info->trans_aborted) {
+		spin_unlock(&root->fs_info->trans_lock);
+		return root->fs_info->trans_aborted;
 	}
+
 	spin_unlock(&root->fs_info->trans_lock);
 
 	cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
@@ -99,6 +107,10 @@ loop:
 		kmem_cache_free(btrfs_transaction_cachep, cur_trans);
 		cur_trans = root->fs_info->running_transaction;
 		goto loop;
+	} else if (root->fs_info->trans_aborted) {
+		spin_unlock(&root->fs_info->trans_lock);
+		kmem_cache_free(btrfs_transaction_cachep, cur_trans);
+		return root->fs_info->trans_aborted;
 	}
 
 	atomic_set(&cur_trans->num_writers, 1);
@@ -1209,6 +1221,8 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans,
 		root->fs_info->running_transaction = NULL;
 		root->fs_info->trans_no_join = 0;
 	}
+	if (!root->fs_info->trans_aborted)
+		root->fs_info->trans_aborted = -EROFS;
 	spin_unlock(&root->fs_info->trans_lock);
 
 	btrfs_cleanup_one_transaction(trans->transaction, root);
-- 
1.7.7.6