Add a little comment explaining the use of PG_private in the NFS client. Signed-off-by: Peter Zijlstra CC: Trond Myklebust --- fs/nfs/write.c | 5 +++++ 1 file changed, 5 insertions(+) Index: linux-2.6/fs/nfs/write.c =================================================================== --- linux-2.6.orig/fs/nfs/write.c +++ linux-2.6/fs/nfs/write.c @@ -417,6 +417,11 @@ static int nfs_inode_add_request(struct if (nfs_have_delegation(inode, FMODE_WRITE)) nfsi->change_attr++; } + /* + * The PG_private bit is unfortunately needed if we want to fix the + * hole in the mmap semantics. If we do not set it, then the VM will + * fail to call the "releasepage" address ops. + */ SetPagePrivate(req->wb_page); nfsi->npages++; atomic_inc(&req->wb_count); --