Btrfs: shift all end_io work to thread pools

bio_end_io for reads without checksumming on and btree writes were
happening without using async thread pools.  This means the extent_io.c
code had to use spin_lock_irq and friends on the rb tree locks for
extent state.

There were some irq safe vs unsafe lock inversions between the delallock
lock and the extent state locks.  This patch gets rid of them by moving
all end_io code into the thread pools.

To avoid contention and deadlocks between the data end_io processing and the
metadata end_io processing yet another thread pool is added to finish
off metadata writes.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b89999de4564..ccea0648e106 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -758,6 +758,7 @@ struct btrfs_fs_info {
         struct btrfs_workers delalloc_workers;
         struct btrfs_workers endio_workers;
         struct btrfs_workers endio_meta_workers;
+        struct btrfs_workers endio_meta_write_workers;
         struct btrfs_workers endio_write_workers;
         struct btrfs_workers submit_workers;
         /*