Hi all, fstests test generic/430 would hang when testing NFSv4.2 using 4.12-rc1 kernel based client. And this is a regression, 4.11 kernel has no problem. A simple reproducer is like: # mount -t nfs -o vers=4.2 nfs-server:/export /mnt/nfs # xfs_io -fc "pwrite 0 4k" /mnt/nfs/testfile # xfs_io -fc "copy_range /mnt/nfs/testfile" /mnt/nfs/testfile.copy The last copy_range command never returns, and xfs_io process is in D state. Some kernel debug code shows that it stuck in infinite loop in nfs42_proc_copy(), _nfs42_proc_copy() always returns -EAGAIN. So this looks like a problem introduced by this commit commit e092693443b995c8e3a565a73b5fdb05f1260f9b Author: Olga Kornievskaia <kolga@xxxxxxxxxx> Date: Mon May 8 18:02:24 2017 -0400 NFS append COMMIT after synchronous COPY Instead of messing with the commit path which has been causing issues, add a COMMIT op after the COPY and ask for stable copies in the first space. It saves a round trip, since after the COPY, the client sends a COMMIT anyway. Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Reverting this patch did solve the problem. If you need more info please let me know. Thanks, Eryu -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html