Btrfs: Create a work queue for bio writes

This allows checksumming to happen in parallel among many cpus, and
keeps us from bogging down pdflush with the checksumming code.

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

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index b47859ccd78a..232300d13be2 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -24,11 +24,12 @@
 
 struct extent_state;
 
+typedef int (extent_submit_bio_hook_t)(struct inode *inode, int rw,
+                                       struct bio *bio, int mirror_num);
 struct extent_io_ops {
         int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
         int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
-        int (*submit_bio_hook)(struct inode *inode, int rw, struct bio *bio,
-                               int mirror_num);
+        extent_submit_bio_hook_t *submit_bio_hook;
         int (*merge_bio_hook)(struct page *page, unsigned long offset,
                               size_t size, struct bio *bio);
         int (*readpage_io_hook)(struct page *page, u64 start, u64 end);