NFSD introduce async copy feature
Upon receiving a request for async copy, create a new kthread. If we
get asynchronous request, make sure to copy the needed arguments/state
from the stack before starting the copy. Then start the thread and reply
back to the client indicating copy is asynchronous.
nfsd_copy_file_range() will copy in a loop over the total number of
bytes is needed to copy. In case a failure happens in the middle, we
ignore the error and return how much we copied so far. Once done
creating a workitem for the callback workqueue and send CB_OFFLOAD with
the results.
The lifetime of the copy stateid is bound to the vfs copy. This way we
don't need to keep the nfsd_net structure for the callback. We could
keep it around longer so that an OFFLOAD_STATUS that came late would
still get results, but clients should be able to deal without that.
We handle OFFLOAD_CANCEL by sending a signal to the copy thread and
calling kthread_stop.
A client should cancel any ongoing copies before calling DESTROY_CLIENT;
if not, we return a CLIENT_BUSY error.
If the client is destroyed for some other reason (lease expiration, or
server shutdown), we must clean up any ongoing copies ourselves.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
[colin.king@canonical.com: fix leak in error case]
[bfields@fieldses.org: remove signalling, merge patches]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index b78280a..3de42a7 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -4231,15 +4231,27 @@ nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
#endif /* CONFIG_NFSD_PNFS */
static __be32
-nfsd42_encode_write_res(struct nfsd4_compoundres *resp, struct nfsd42_write_res *write)
+nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
+ struct nfsd42_write_res *write, bool sync)
{
__be32 *p;
-
- p = xdr_reserve_space(&resp->xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
+ p = xdr_reserve_space(&resp->xdr, 4);
if (!p)
return nfserr_resource;
- *p++ = cpu_to_be32(0);
+ if (sync)
+ *p++ = cpu_to_be32(0);
+ else {
+ __be32 nfserr;
+ *p++ = cpu_to_be32(1);
+ nfserr = nfsd4_encode_stateid(&resp->xdr, &write->cb_stateid);
+ if (nfserr)
+ return nfserr;
+ }
+ p = xdr_reserve_space(&resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
+ if (!p)
+ return nfserr_resource;
+
p = xdr_encode_hyper(p, write->wr_bytes_written);
*p++ = cpu_to_be32(write->wr_stable_how);
p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
@@ -4253,7 +4265,8 @@ nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
{
__be32 *p;
- nfserr = nfsd42_encode_write_res(resp, ©->cp_res);
+ nfserr = nfsd42_encode_write_res(resp, ©->cp_res,
+ copy->cp_synchronous);
if (nfserr)
return nfserr;