Currently GETATTR conflict with a write delegation is handled by recalling the delegation before replying to the GETATTR. This patch series add supports for CB_GETATTR callback to get the latest change_info and size information of the file from the client that holds the delegation to reply to the GETATTR from the second client. NOTE: this patch series is mostly the same as the previous patches which were backed out when un unrelated problem of NFSD server hang on reboot was reported. The only difference is the wait_on_bit() in nfsd4_deleg_getattr_conflict was replaced with wait_on_bit_timeout() with 30ms timeout to avoid a potential DOS attack by exhausting NFSD kernel threads with GETATTR conflicts. v2: . update comments in nfsd4_deleg_getattr_conflict v3: . rebase with nfsd-next fs/nfsd/nfs4callback.c | 97 ++++++++++++++++++++++++++++++++++++- fs/nfsd/nfs4state.c | 115 ++++++++++++++++++++++++++++++++++++++++---- fs/nfsd/nfs4xdr.c | 10 +++- fs/nfsd/nfsd.h | 1 + fs/nfsd/state.h | 24 ++++++++- fs/nfsd/xdr4cb.h | 18 +++++++ 6 files changed, 251 insertions(+), 14 deletions(-)
