[PATCH 02/28] xfs: re-enable non-blocking behaviour in xfs_map_blocks

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

The non-blockig behaviour in xfs_vm_writepage currently is conditional on
having both the WB_SYNC_NONE sync_mode and the nonblocking flag set.
The latter used to be used by both pdflush, kswapd and a few other places
in older kernels, but has been fading out starting with the introduction
of the per-bdi flusher threads.

Enable the non-blocking behaviour for all WB_SYNC_NONE calls to get back
the behaviour we want.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Alex Elder <aelder@xxxxxxx>

Index: xfs/fs/xfs/linux-2.6/xfs_aops.c
===================================================================
--- xfs.orig/fs/xfs/linux-2.6/xfs_aops.c        2011-07-06 09:12:22.466600907 
+0200
+++ xfs/fs/xfs/linux-2.6/xfs_aops.c     2011-07-06 09:12:26.069934110 +0200
@@ -960,7 +960,7 @@ xfs_vm_writepage(
        offset = page_offset(page);
        type = IO_OVERWRITE;
 
-       if (wbc->sync_mode == WB_SYNC_NONE && wbc->nonblocking)
+       if (wbc->sync_mode == WB_SYNC_NONE)
                nonblocking = 1;
 
        do {