From c63c7b051395368573779c8309aa5c990dcf2f96 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 2 Apr 2007 19:29:52 -0400 Subject: NFS: Fix a race when doing NFS write coalescing Currently we do write coalescing in a very inefficient manner: one pass in generic_writepages() in order to lock the pages for writing, then one pass in nfs_flush_mapping() and/or nfs_sync_mapping_wait() in order to gather the locked pages for coalescing into RPC requests of size "wsize". In fact, it turns out there is actually a deadlock possible here since we only start I/O on the second pass. If the user signals the process while we're in nfs_sync_mapping_wait(), for instance, then we may exit before starting I/O on all the requests that have been queued up. Signed-off-by: Trond Myklebust --- include/linux/writeback.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 0c78f7f4a976..daa6c125f66e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -59,6 +59,8 @@ struct writeback_control { unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned for_writepages:1; /* This is a writepages() call */ unsigned range_cyclic:1; /* range_start is cyclic */ + + void *fs_private; /* For use by ->writepages() */ }; /* -- cgit v1.2.3