ocfs2: Use GFP_NOFS in kmalloc during localalloc window move

kmalloc() during a localalloc window move can trigger the mm to prune
the dcache which inturn can trigger the fs to delete an inode causing
it start a recursive transaction.

The fix also makes the change in kmalloc during localalloc shutdown
just to be safe.

Fixes oss bugzilla#901
http://oss.oracle.com/bugzilla/show_bug.cgi?id=901

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

fs/ocfs2/localalloc.c

@@ -260,7 +260,7 @@ void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
 	bh = osb->local_alloc_bh;
 	alloc = (struct ocfs2_dinode *) bh->b_data;
 
-	alloc_copy = kmalloc(bh->b_size, GFP_KERNEL);
+	alloc_copy = kmalloc(bh->b_size, GFP_NOFS);
 	if (!alloc_copy) {
 		status = -ENOMEM;
 		goto out_commit;
@@ -931,7 +931,7 @@ static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
 	 * local alloc shutdown won't try to double free main bitmap
 	 * bits. Make a copy so the sync function knows which bits to
 	 * free. */
-	alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_KERNEL);
+	alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_NOFS);
 	if (!alloc_copy) {
 		status = -ENOMEM;
 		mlog_errno(status);