tree a509b1daf6e41f7768eaf49235c573690f12ef9b
parent 333db94cdde9e6dfdedab9290d04d812f83e0922
author Chris Mason <chris.mason@oracle.com> 1214424091 -0400
committer Chris Mason <chris.mason@oracle.com> 1222355043 -0400

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>