Btrfs: Fixes for 2.6.18 enterprise kernels

2.6.18 seems to get caught in an infinite loop when
cancel_rearming_delayed_workqueue is called more than once, so this switches
to cancel_delayed_work, which is arguably more correct.

Also, balance_dirty_pages can run into problems with 2.6.18 based kernels
because it doesn't have the per-bdi dirty limits.  This avoids calling
balance_dirty_pages on the btree inode unless there is actually something
to balance, which is a good optimization in general.

Finally there's a compile fix for ordered-data.h

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

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index c85cb48d95ee..9826942fa18a 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -814,6 +814,9 @@ void btrfs_transaction_cleaner(struct work_struct *work)
         int ret;
 
         mutex_lock(&root->fs_info->fs_mutex);
+        if (root->fs_info->closing)
+                goto out;
+
         mutex_lock(&root->fs_info->trans_mutex);
         cur = root->fs_info->running_transaction;
         if (!cur) {
@@ -838,12 +841,13 @@ out:
 
 void btrfs_transaction_queue_work(struct btrfs_root *root, int delay)
 {
-        queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
+        if (!root->fs_info->closing)
+                queue_delayed_work(trans_wq, &root->fs_info->trans_work, delay);
 }
 
 void btrfs_transaction_flush_work(struct btrfs_root *root)
 {
-        cancel_rearming_delayed_workqueue(trans_wq, &root->fs_info->trans_work);
+        cancel_delayed_work(&root->fs_info->trans_work);
         flush_workqueue(trans_wq);
 }