> On Sep 28, 2017, at 2:07 PM, J. Bruce Fields <bfields@xxxxxxxxxx> wrote:
>
> On Thu, Sep 28, 2017 at 01:29:40PM -0400, Olga Kornievskaia wrote:
>> Asynchronous copies are handled by a single threaded workqueue.
>> If we get asynchronous request, make sure to copy the needed
>> arguments/state from the stack before starting the copy. Then
>> queue work and reply back to the client indicating copy is
>> asynchronous.
>>
>> nfsd_copy_file_range() will copy in 4MBchunk so do a loop over
>> the total number of bytes need to copy.
>
> I don't think you need to do this--just call vfs_copy_file_range()
> directly, as nfsd_copy_file_range does.
>
> The 4MB chunking was only there to prevent a synchronous copy from
> taking too long, which isn't an issue in the async case.
>
One reason is to allow for the copy to be cancelled in the “middle”.
Otherwise, we have no control over once we call into the vfs_copy_file_range
to stop the on-going copy. At least this way we check every 4MB chunks.
> --b.
>
>> In case a failure
>> happens in the middle, we can return an error as well as how
>> much we copied so far. Once done creating a workitem for the
>> callback workqueue and send CB_OFFLOAD with the results.
>>
>> Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
>> ---
>> fs/nfsd/nfs4proc.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++------
>> fs/nfsd/nfs4state.c | 9 ++-
>> fs/nfsd/state.h | 2 +
>> fs/nfsd/xdr4.h | 7 +++
>> 4 files changed, 162 insertions(+), 20 deletions(-)
>>
>> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
>> index 11ade90..de21b1a 100644
>> --- a/fs/nfsd/nfs4proc.c
>> +++ b/fs/nfsd/nfs4proc.c
>> @@ -76,6 +76,21 @@
>> { }
>> #endif
>>
>> +static struct workqueue_struct *copy_wq;
>> +
>> +int nfsd4_create_copy_queue(void)
>> +{
>> + copy_wq = create_singlethread_workqueue("nfsd4_copy");
>> + if (!copy_wq)
>> + return -ENOMEM;
>> + return 0;
>> +}
>> +
>> +void nfsd4_destroy_copy_queue(void)
>> +{
>> + destroy_workqueue(copy_wq);
>> +}
>> +
>> #define NFSDDBG_FACILITY NFSDDBG_PROC
>>
>> static u32 nfsd_attrmask[] = {
>> @@ -1085,37 +1100,148 @@ static int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write)
>> out:
>> return status;
>> }
>> +static void nfsd4_cb_offload_release(struct nfsd4_callback *cb)
>> +{
>> + struct nfsd4_copy *copy = container_of(cb, struct nfsd4_copy, cp_cb);
>> +
>> + kfree(copy);
>> +}
>> +
>> +static int nfsd4_cb_offload_done(struct nfsd4_callback *cb,
>> + struct rpc_task *task)
>> +{
>> + return 1;
>> +}
>> +
>> +static const struct nfsd4_callback_ops nfsd4_cb_offload_ops = {
>> + .release = nfsd4_cb_offload_release,
>> + .done = nfsd4_cb_offload_done
>> +};
>> +
>> +static int nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync)
>> +{
>> + memcpy(©->cp_res.cb_stateid, ©->cp_dst_stateid,
>> + sizeof(copy->cp_dst_stateid));
>> + copy->cp_res.wr_stable_how = NFS_UNSTABLE;
>> + copy->cp_consecutive = 1;
>> + copy->cp_synchronous = sync;
>> + gen_boot_verifier(©->cp_res.wr_verifier, copy->net);
>> +
>> + return nfs_ok;
>> +}
>> +
>> +static int _nfsd_copy_file_range(struct nfsd4_copy *copy)
>> +{
>> + ssize_t bytes_copied = 0;
>> + size_t bytes_total = copy->cp_count;
>> + size_t bytes_to_copy;
>> + u64 src_pos = copy->cp_src_pos;
>> + u64 dst_pos = copy->cp_dst_pos;
>> +
>> + do {
>> + bytes_to_copy = min_t(u64, bytes_total, MAX_RW_COUNT);
>> + bytes_copied = nfsd_copy_file_range(copy->fh_src, src_pos,
>> + copy->fh_dst, dst_pos, bytes_to_copy);
>> + if (bytes_copied <= 0)
>> + break;
>> + bytes_total -= bytes_copied;
>> + copy->cp_res.wr_bytes_written += bytes_copied;
>> + src_pos += bytes_copied;
>> + dst_pos += bytes_copied;
>> + } while (bytes_total > 0 && !copy->cp_synchronous);
>> + return bytes_copied;
>> +}
>> +
>> +static int nfsd4_do_copy(struct nfsd4_copy *copy, bool sync)
>> +{
>> + __be32 status;
>> + ssize_t bytes;
>> +
>> + bytes = _nfsd_copy_file_range(copy);
>> + if (bytes < 0)
>> + status = nfserrno(bytes);
>> + else
>> + status = nfsd4_init_copy_res(copy, sync);
>> +
>> + fput(copy->fh_src);
>> + fput(copy->fh_dst);
>> + return status;
>> +}
>> +
>> +static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst)
>> +{
>> + memcpy(&dst->cp_src_stateid, &src->cp_src_stateid, sizeof(stateid_t));
>> + memcpy(&dst->cp_dst_stateid, &src->cp_dst_stateid, sizeof(stateid_t));
>> + dst->cp_src_pos = src->cp_src_pos;
>> + dst->cp_dst_pos = src->cp_dst_pos;
>> + dst->cp_count = src->cp_count;
>> + dst->cp_consecutive = src->cp_consecutive;
>> + dst->cp_synchronous = src->cp_synchronous;
>> + memcpy(&dst->cp_res, &src->cp_res, sizeof(src->cp_res));
>> + /* skipping nfsd4_callback */
>> + memcpy(&dst->fh, &src->fh, sizeof(src->fh));
>> + dst->fh = src->fh;
>> + dst->cp_clp = src->cp_clp;
>> + dst->fh_src = src->fh_src;
>> + dst->fh_dst = src->fh_dst;
>> + dst->net = src->net;
>> +}
>> +
>> +static void nfsd4_do_async_copy(struct work_struct *work)
>> +{
>> + struct nfsd4_copy *copy =
>> + container_of(work, struct nfsd4_copy, cp_work);
>> + struct nfsd4_copy *cb_copy;
>> +
>> + copy->nfserr = nfsd4_do_copy(copy, 0);
>> + cb_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
>> + if (!cb_copy)
>> + goto out;
>> + memcpy(&cb_copy->cp_res, ©->cp_res, sizeof(copy->cp_res));
>> + cb_copy->cp_clp = copy->cp_clp;
>> + cb_copy->nfserr = copy->nfserr;
>> + memcpy(&cb_copy->fh, ©->fh, sizeof(copy->fh));
>> + nfsd4_init_cb(&cb_copy->cp_cb, cb_copy->cp_clp,
>> + &nfsd4_cb_offload_ops, NFSPROC4_CLNT_CB_OFFLOAD);
>> + nfsd4_run_cb(&cb_copy->cp_cb);
>> +out:
>> + kfree(copy);
>> +}
>>
>> static __be32
>> nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>> union nfsd4_op_u *u)
>> {
>> struct nfsd4_copy *copy = &u->copy;
>> - struct file *src, *dst;
>> __be32 status;
>> - ssize_t bytes;
>>
>> - status = nfsd4_verify_copy(rqstp, cstate, ©->cp_src_stateid, &src,
>> - ©->cp_dst_stateid, &dst);
>> + status = nfsd4_verify_copy(rqstp, cstate, ©->cp_src_stateid,
>> + ©->fh_src, ©->cp_dst_stateid,
>> + ©->fh_dst);
>> if (status)
>> goto out;
>>
>> - bytes = nfsd_copy_file_range(src, copy->cp_src_pos,
>> - dst, copy->cp_dst_pos, copy->cp_count);
>> -
>> - if (bytes < 0)
>> - status = nfserrno(bytes);
>> - else {
>> - copy->cp_res.wr_bytes_written = bytes;
>> - copy->cp_res.wr_stable_how = NFS_UNSTABLE;
>> - copy->cp_consecutive = 1;
>> - copy->cp_synchronous = 1;
>> - gen_boot_verifier(©->cp_res.wr_verifier, SVC_NET(rqstp));
>> - status = nfs_ok;
>> + copy->cp_clp = cstate->clp;
>> + memcpy(©->fh, &cstate->current_fh.fh_handle,
>> + sizeof(struct knfsd_fh));
>> + copy->net = SVC_NET(rqstp);
>> + if (!copy->cp_synchronous) {
>> + struct nfsd4_copy *async_copy;
>> +
>> + status = nfsd4_init_copy_res(copy, 0);
>> + async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
>> + if (!async_copy) {
>> + status = nfserrno(-ENOMEM);
>> + goto out;
>> + }
>> + dup_copy_fields(copy, async_copy);
>> + memcpy(©->cp_res.cb_stateid, ©->cp_dst_stateid,
>> + sizeof(copy->cp_dst_stateid));
>> + INIT_WORK(&async_copy->cp_work, nfsd4_do_async_copy);
>> + queue_work(copy_wq, &async_copy->cp_work);
>> + } else {
>> + status = nfsd4_do_copy(copy, 1);
>> }
>> -
>> - fput(src);
>> - fput(dst);
>> out:
>> return status;
>> }
>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>> index 0c04f81..fe6f275 100644
>> --- a/fs/nfsd/nfs4state.c
>> +++ b/fs/nfsd/nfs4state.c
>> @@ -7033,8 +7033,14 @@ static int nfs4_state_create_net(struct net *net)
>> goto out_free_laundry;
>>
>> set_max_delegations();
>> - return 0;
>>
>> + ret = nfsd4_create_copy_queue();
>> + if (ret)
>> + goto out_free_callback;
>> +
>> + return 0;
>> +out_free_callback:
>> + nfsd4_destroy_callback_queue();
>> out_free_laundry:
>> destroy_workqueue(laundry_wq);
>> out_cleanup_cred:
>> @@ -7097,6 +7103,7 @@ static int nfs4_state_create_net(struct net *net)
>> destroy_workqueue(laundry_wq);
>> nfsd4_destroy_callback_queue();
>> cleanup_callback_cred();
>> + nfsd4_destroy_copy_queue();
>> }
>>
>> static void
>> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
>> index f8b0210..b5358cf 100644
>> --- a/fs/nfsd/state.h
>> +++ b/fs/nfsd/state.h
>> @@ -630,6 +630,8 @@ extern void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
>> extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name,
>> struct nfsd_net *nn);
>> extern bool nfs4_has_reclaimed_state(const char *name, struct nfsd_net *nn);
>> +extern int nfsd4_create_copy_queue(void);
>> +extern void nfsd4_destroy_copy_queue(void);
>>
>> struct nfs4_file *find_file(struct knfsd_fh *fh);
>> void put_nfs4_file(struct nfs4_file *fi);
>> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
>> index 9b0c099..f7a94d3 100644
>> --- a/fs/nfsd/xdr4.h
>> +++ b/fs/nfsd/xdr4.h
>> @@ -529,6 +529,13 @@ struct nfsd4_copy {
>> struct nfsd4_callback cp_cb;
>> __be32 nfserr;
>> struct knfsd_fh fh;
>> +
>> + struct work_struct cp_work;
>> + struct nfs4_client *cp_clp;
>> +
>> + struct file *fh_src;
>> + struct file *fh_dst;
>> + struct net *net;
>> };
>>
>> struct nfsd4_seek {
>> --
>> 1.8.3.1
>>
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