Hi, when I tested xfstests/generic/323 with NFSv4.1 and v4.2, the task changed to zombie occasionally while a thread is hanging with the following stack: [<0>] rpc_wait_bit_killable+0x1e/0xa0 [sunrpc] [<0>] nfs4_do_close+0x21b/0x2c0 [nfsv4] [<0>] __put_nfs_open_context+0xa2/0x110 [nfs] [<0>] nfs_file_release+0x35/0x50 [nfs] [<0>] __fput+0xa2/0x1c0 [<0>] task_work_run+0x82/0xa0 [<0>] do_exit+0x2ac/0xc20 [<0>] do_group_exit+0x39/0xa0 [<0>] get_signal+0x1ce/0x5d0 [<0>] do_signal+0x36/0x620 [<0>] exit_to_usermode_loop+0x5e/0xc2 [<0>] do_syscall_64+0x16c/0x190 [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [<0>] 0xffffffffffffffff Since commit 12f275cdd163(NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID), the client will retry to close the file when stateid generation number in client is lower than server. The original intention of this commit is retrying the operation while racing with an OPEN. However, in this case the stateid generation remains mismatch forever. Any suggestions? Thanks, Jiufei
