To do asynchronous copies, NFSD creates a new kthread to handle the request. Upon receiving the COPY, it generates a unique copy stateid (stored in a global list for keeping track of state for OFFLOAD_STATUS to be queried by), starts the thread, and replies back to the client. nfsd4_copy arguments that are allocated on the stack are copies for the kthread. For the async copy handler, copy is done in the loop for the requested number of bytes. If an error is encountered and partial copy has happened, a successful partial copy is returned in the CB_OFFLOAD. vfs_copy_file_range is called with 4MB chunks for both async and sync, allowing for 4MB granularity of OFFLOAD_STATUS queiry. Once copy is done, the results are queued for the callback workqueue and sent via CB_OFFLOAD. When the server received an OFFLOAD_CANCEL, it will find the kthread running the copy and will send a SIGPENDING and kthread_stop() and it will interrupt the ongoing do_splice() and once vfs returns we are choosing not to send the CB_OFFLOAD back to the client. When the server receives an OFFLOAD_STATUS, it will find the kthread running the copy and will locate within the copy state the current number of bytes copied so far. v6: 1. if an error occured and partial bytes were copied, don't return the error and instead return the successful partial copy. 2. OFFLOAD_STATUS locates the on-going copy and looks up the number of bytes copied so far. Olga Kornievskaia (10): NFSD CB_OFFLOAD xdr NFSD OFFLOAD_STATUS xdr NFSD OFFLOAD_CANCEL xdr NFSD xdr callback stateid in async COPY reply NFSD first draft of async copy NFSD return nfs4_stid in nfs4_preprocess_stateid_op NFSD create new stateid for async copy NFSD handle OFFLOAD_CANCEL op NFSD support OFFLOAD_STATUS NFSD stop queued async copies on client shutdown fs/nfsd/netns.h | 8 ++ fs/nfsd/nfs4callback.c | 97 +++++++++++++++ fs/nfsd/nfs4proc.c | 316 ++++++++++++++++++++++++++++++++++++++++++++----- fs/nfsd/nfs4state.c | 77 +++++++++++- fs/nfsd/nfs4xdr.c | 50 ++++++-- fs/nfsd/nfsctl.c | 1 + fs/nfsd/state.h | 21 +++- fs/nfsd/xdr4.h | 28 +++++ fs/nfsd/xdr4cb.h | 10 ++ 9 files changed, 571 insertions(+), 37 deletions(-) -- 1.8.3.1 -- 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
