Add btrfs_end_transaction_throttle to force writers to wait for pending commits
The existing throttle mechanism was often not sufficient to prevent
new writers from coming in and making a given transaction run forever.
This adds an explicit wait at the end of most operations so they will
allow the current transaction to close.
There is no wait inside file_write, inode updates, or cow filling, all which
have different deadlock possibilities.
This is a temporary measure until better asynchronous commit support is
added. This code leads to stalls as it waits for data=ordered
writeback, and it really needs to be fixed.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index c3172dd..52559b5 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -101,4 +101,6 @@
struct btrfs_root *root);
int btrfs_write_ordered_inodes(struct btrfs_trans_handle *trans,
struct btrfs_root *root);
+int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root);
#endif