On Thu, Sep 28, 2017 at 01:29:43PM -0400, Olga Kornievskaia wrote:
> Upon receiving OFFLOAD_CANCEL search the list of copy stateids,
> if found mark it cancelled. If copy has more interations to
> call vfs_copy_file_range, it'll stop it. Server won't be sending
> CB_OFFLOAD to the client since it received a cancel.
>
> Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4proc.c | 26 ++++++++++++++++++++++++--
> fs/nfsd/nfs4state.c | 16 ++++++++++++++++
> fs/nfsd/state.h | 4 ++++
> 3 files changed, 44 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 3cddebb..f4f3d93 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -1139,6 +1139,7 @@ static int _nfsd_copy_file_range(struct nfsd4_copy *copy)
> size_t bytes_to_copy;
> u64 src_pos = copy->cp_src_pos;
> u64 dst_pos = copy->cp_dst_pos;
> + bool cancelled = false;
>
> do {
> bytes_to_copy = min_t(u64, bytes_total, MAX_RW_COUNT);
> @@ -1150,7 +1151,12 @@ static int _nfsd_copy_file_range(struct nfsd4_copy *copy)
> copy->cp_res.wr_bytes_written += bytes_copied;
> src_pos += bytes_copied;
> dst_pos += bytes_copied;
> - } while (bytes_total > 0 && !copy->cp_synchronous);
> + if (!copy->cp_synchronous) {
> + spin_lock(©->cps->cp_lock);
> + cancelled = copy->cps->cp_cancelled;
> + spin_unlock(©->cps->cp_lock);
> + }
> + } while (bytes_total > 0 && !copy->cp_synchronous && !cancelled);
> return bytes_copied;
I'd rather we sent a signal, and then we won't need this
logic--vfs_copy_range() will just return EINTR or something.
That will help us get rid of the 4MB-at-a-time loop. And will mean we
don't need to wait for the next 4MB copy to finish before stopping the
loop. Normally I wouldn't expect that to take too long, but it might.
And a situation where a cancel is sent is a situation where we're
probably more likely to have some problem slowing down the copy.
Also: don't we want OFFLOAD_CANCEL to wait until the cancel has actually
taken effect before returning?
I can't see any language in the spec to that affect, but it would seem
surprising to me if I got back a succesful response to OFFLOAD_CANCEL
and then noticed that the target file was still changing.
--b.
> }
>
> @@ -1198,6 +1204,10 @@ static void nfsd4_do_async_copy(struct work_struct *work)
> struct nfsd4_copy *cb_copy;
>
> copy->nfserr = nfsd4_do_copy(copy, 0);
> +
> + if (copy->cps->cp_cancelled)
> + goto out;
> +
> cb_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL);
> if (!cb_copy)
> goto out;
> @@ -1269,7 +1279,19 @@ static void nfsd4_do_async_copy(struct work_struct *work)
> struct nfsd4_compound_state *cstate,
> union nfsd4_op_u *u)
> {
> - return 0;
> + struct nfsd4_offload_status *os = &u->offload_status;
> + struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
> + __be32 status;
> + struct nfs4_cp_state *state = NULL;
> +
> + status = find_cp_state(nn, &os->stateid, &state);
> + if (state) {
> + spin_lock(&state->cp_lock);
> + state->cp_cancelled = true;
> + spin_unlock(&state->cp_lock);
> + }
> +
> + return status;
> }
>
> static __be32
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index be59baf..97ab3f8 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -752,6 +752,22 @@ static void nfs4_free_deleg(struct nfs4_stid *stid)
> atomic_long_dec(&num_delegations);
> }
>
> +__be32 find_cp_state(struct nfsd_net *nn, stateid_t *st,
> + struct nfs4_cp_state **cps)
> +{
> + struct nfs4_cp_state *state = NULL;
> +
> + if (st->si_opaque.so_clid.cl_id != nn->s2s_cp_cl_id)
> + return nfserr_bad_stateid;
> + spin_lock(&nn->s2s_cp_lock);
> + state = idr_find(&nn->s2s_cp_stateids, st->si_opaque.so_id);
> + spin_unlock(&nn->s2s_cp_lock);
> + if (!state)
> + return nfserr_bad_stateid;
> + *cps = state;
> + return 0;
> +}
> +
> /*
> * When we recall a delegation, we should be careful not to hand it
> * out again straight away.
> diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> index 8724955..7a070d5 100644
> --- a/fs/nfsd/state.h
> +++ b/fs/nfsd/state.h
> @@ -111,6 +111,8 @@ struct nfs4_cp_state {
> stateid_t cp_stateid;
> struct list_head cp_list; /* per parent nfs4_stid */
> struct nfs4_stid *cp_p_stid; /* pointer to parent */
> + bool cp_cancelled; /* copy cancelled */
> + spinlock_t cp_lock;
> };
>
> /*
> @@ -647,6 +649,8 @@ extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(const char *name,
> 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);
> +extern __be32 find_cp_state(struct nfsd_net *nn, stateid_t *st,
> + struct nfs4_cp_state **cps);
>
> struct nfs4_file *find_file(struct knfsd_fh *fh);
> void put_nfs4_file(struct nfs4_file *fi);
> --
> 1.8.3.1
>
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