btrfs_start_transaction: wait for commits in progress to finish
btrfs_commit_transaction has to loop waiting for any writers in the
transaction to finish before it can proceed. btrfs_start_transaction
should be polite and not join a transaction that is in the process
of being finished off.
There are a few places that can't wait, basically the ones doing IO that
might be needed to finish the transaction. For them, btrfs_join_transaction
is added.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 910350c..11fbdec 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -27,6 +27,7 @@
int in_commit;
int use_count;
int commit_done;
+ int blocked;
struct list_head list;
struct extent_io_tree dirty_pages;
unsigned long start_time;
@@ -75,6 +76,8 @@
struct btrfs_root *root);
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
int num_blocks);
+struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
+ int num_blocks);
int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
int btrfs_commit_tree_roots(struct btrfs_trans_handle *trans,