[XFS] Introduce per-filesystem delwri pagebuf flushing to reduce

contention between filesystems and prevent deadlocks between filesystems
when a flush dependency exists between them.

SGI-PV: 947098
SGI-Modid: xfs-linux-melb:xfs-kern:24844a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index 237a35b915d1..f721d47ad4cc 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -88,6 +88,15 @@ typedef struct xfs_buftarg {
         uint                    bt_hashmask;
         uint                    bt_hashshift;
         xfs_bufhash_t           *bt_hash;
+
+        /* per device delwri queue */
+        struct task_struct      *bt_task;
+        struct list_head        bt_list;
+        struct list_head        bt_delwrite_queue;
+        spinlock_t              bt_delwrite_lock;
+        uint                    bt_flags;
+#define BT_FORCE_SLEEP          1
+#define BT_FORCE_FLUSH          2
 } xfs_buftarg_t;
 
 /*