On Tue, Feb 20, 2018 at 11:42:24AM -0500, Olga Kornievskaia wrote:
> 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.
Might be worth including a comment explaining this (that we ignore the
error, and that the client can always retry after a short read if it
wants an error), maybe as a comment to the
(bytes < 0 && !copy->cp_res.wr_bytes_written)
condition in nfsd4_do_copy().
--b.
> Once done creating a workitem for the callback
> workqueue and send CB_OFFLOAD with the results.
>
> In the following patches the unique stateid will be generated
> for the async COPY to return, at that point will enable the
> async feature.
>
> Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4proc.c | 176 ++++++++++++++++++++++++++++++++++++++++++++++------
> fs/nfsd/nfs4state.c | 2 +
> fs/nfsd/state.h | 2 +
> fs/nfsd/xdr4.h | 9 +++
> 4 files changed, 170 insertions(+), 19 deletions(-)
>
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index e11494f..91d1544 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -35,6 +35,7 @@
> #include <linux/file.h>
> #include <linux/falloc.h>
> #include <linux/slab.h>
> +#include <linux/kthread.h>
>
> #include "idmap.h"
> #include "cache.h"
> @@ -1083,39 +1084,176 @@ 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);
> +
> + atomic_dec(©->cp_clp->cl_refcount);
> + 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;
> + u64 src_pos = copy->cp_src_pos;
> + u64 dst_pos = copy->cp_dst_pos;
> +
> + do {
> + bytes_copied = nfsd_copy_file_range(copy->fh_src, src_pos,
> + copy->fh_dst, dst_pos, bytes_total);
> + 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 && !copy->cp_res.wr_bytes_written)
> + 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->net = src->net;
> + dst->cp_clp = src->cp_clp;
> + atomic_inc(&dst->cp_clp->cl_refcount);
> + dst->fh_dst = get_file(src->fh_dst);
> + dst->fh_src = get_file(src->fh_src);
> +}
> +
> +static void cleanup_async_copy(struct nfsd4_copy *copy, bool remove)
> +{
> + fput(copy->fh_dst);
> + fput(copy->fh_src);
> + if (remove) {
> + spin_lock(©->cp_clp->async_lock);
> + list_del(©->copies);
> + spin_unlock(©->cp_clp->async_lock);
> + }
> + atomic_dec(©->cp_clp->cl_refcount);
> + kfree(copy);
> +}
> +
> +static int nfsd4_do_async_copy(void *data)
> +{
> + struct nfsd4_copy *copy = (struct nfsd4_copy *)data;
> + 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;
> + atomic_inc(&cb_copy->cp_clp->cl_refcount);
> + 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:
> + cleanup_async_copy(copy, true);
> + return 0;
> +}
>
> 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;
> + struct nfsd4_copy *async_copy = NULL;
>
> - 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);
> + /* for now disable asynchronous copy feature */
> + copy->cp_synchronous = 1;
> + if (!copy->cp_synchronous) {
> + 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));
> + async_copy->copy_task = kthread_create(nfsd4_do_async_copy,
> + async_copy, "%s", "copy thread");
> + if (IS_ERR(async_copy->copy_task)) {
> + status = PTR_ERR(async_copy->copy_task);
> + goto out_err;
> + }
> + spin_lock(&async_copy->cp_clp->async_lock);
> + list_add(&async_copy->copies,
> + &async_copy->cp_clp->async_copies);
> + spin_unlock(&async_copy->cp_clp->async_lock);
> + wake_up_process(async_copy->copy_task);
> + } else {
> + status = nfsd4_do_copy(copy, 1);
> }
> -
> - fput(src);
> - fput(dst);
> out:
> return status;
> +out_err:
> + cleanup_async_copy(async_copy, false);
> + goto out;
> }
>
> static __be32
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 150521c..fe665b0 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -1790,6 +1790,8 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
> #ifdef CONFIG_NFSD_PNFS
> INIT_LIST_HEAD(&clp->cl_lo_states);
> #endif
> + INIT_LIST_HEAD(&clp->async_copies);
> + spin_lock_init(&clp->async_lock);
> spin_lock_init(&clp->cl_lock);
> rpc_init_wait_queue(&clp->cl_cb_waitq, "Backchannel slot table");
> return clp;
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index 5c16d35..491030e 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -355,6 +355,8 @@ struct nfs4_client {
> struct rpc_wait_queue cl_cb_waitq; /* backchannel callers may */
> /* wait here for slots */
> struct net *net;
> + struct list_head async_copies; /* list of async copies */
> + spinlock_t async_lock; /* lock for async copies */
> };
>
> /* struct nfs4_client_reset
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index 4fc0e35..3b6b655 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -529,6 +529,15 @@ struct nfsd4_copy {
> struct nfsd4_callback cp_cb;
> __be32 nfserr;
> struct knfsd_fh fh;
> +
> + struct nfs4_client *cp_clp;
> +
> + struct file *fh_src;
> + struct file *fh_dst;
> + struct net *net;
> +
> + struct list_head copies;
> + struct task_struct *copy_task;
> };
>
> struct nfsd4_seek {
> --
> 1.8.3.1
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