On Fri, 2013-07-19 at 17:03 -0400, bjschuma@xxxxxxxxxx wrote:
> From: Bryan Schumaker <bjschuma@xxxxxxxxxx>
>
> Supporting CB_OFFLOAD is required by the spec, so if a server chooses to
> copy in the background we have to wait for the copy to finish before
> returning to userspace.
>
> Signed-off-by: Bryan Schumaker <bjschuma@xxxxxxxxxx>
> ---
> fs/nfs/callback.h | 13 ++++++++++++
> fs/nfs/callback_proc.c | 9 +++++++++
> fs/nfs/callback_xdr.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++---
> fs/nfs/nfs4_fs.h | 3 +++
> fs/nfs/nfs4file.c | 48 +++++++++++++++++++++++++++++++++++++++++++
> fs/nfs/nfs4xdr.c | 4 ++--
> include/linux/nfs_xdr.h | 3 +++
> 7 files changed, 129 insertions(+), 5 deletions(-)
>
> diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
> index 84326e9..ae5a5d2 100644
> --- a/fs/nfs/callback.h
> +++ b/fs/nfs/callback.h
> @@ -187,6 +187,19 @@ extern __be32 nfs4_callback_devicenotify(
> void *dummy, struct cb_process_state *cps);
>
> #endif /* CONFIG_NFS_V4_1 */
> +
> +#ifdef CONFIG_NFS_V4_2
> +struct cb_offloadargs {
> + struct nfs_fh dst_fh;
> + nfs4_stateid stateid;
> + struct nfs42_write_response write_res;
> +};
> +
> +extern __be32 nfs4_callback_offload(struct cb_offloadargs *, void *,
> + struct cb_process_state *);
> +void wake_copy_offload(struct cb_offloadargs *);
> +#endif /* CONFIG_NFS_V4_2 */
> +
> extern int check_gss_callback_principal(struct nfs_client *, struct svc_rqst *);
> extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
> struct cb_getattrres *res,
> diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
> index e6ebc4c..cdf4180 100644
> --- a/fs/nfs/callback_proc.c
> +++ b/fs/nfs/callback_proc.c
> @@ -533,3 +533,12 @@ out:
> return status;
> }
> #endif /* CONFIG_NFS_V4_1 */
> +
> +#ifdef CONFIG_NFS_V4_2
> +__be32 nfs4_callback_offload(struct cb_offloadargs *args, void *dummy,
> + struct cb_process_state *cps)
> +{
> + wake_copy_offload(args);
> + return htonl(NFS4_OK);
> +}
> +#endif /* CONFIG_NFS_V4_2 */
> diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
> index f4ccfe6..d8fcf1a 100644
> --- a/fs/nfs/callback_xdr.c
> +++ b/fs/nfs/callback_xdr.c
> @@ -35,6 +35,14 @@
> #define CB_OP_RECALLSLOT_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ)
> #endif /* CONFIG_NFS_V4_1 */
>
> +#if defined(CONFIG_NFS_V4_2)
> +#define CB_OP_OFFLOAD_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
> + 1 + XDR_QUADLEN(NFS4_FHSIZE) + \
> + XDR_QUADLEN(NFS4_STATEID_SIZE) + \
> + 1 + XDR_QUADLEN(NFS4_STATEID_SIZE) + \
> + 2 + 1 + XDR_QUADLEN(NFS4_VERIFIER_SIZE))
> +#endif /* CONFIG_NFS_V4_2 */
> +
> #define NFSDBG_FACILITY NFSDBG_CALLBACK
>
> /* Internal error code */
> @@ -527,6 +535,37 @@ static __be32 decode_recallslot_args(struct svc_rqst *rqstp,
>
> #endif /* CONFIG_NFS_V4_1 */
>
> +#ifdef CONFIG_NFS_V4_2
> +static inline __be32 decode_write_res(struct xdr_stream *xdr,
> + struct nfs42_write_response *write_res)
> +{
> + __be32 status = decode_write_response(xdr, write_res);
> + if (status == -EIO)
> + return htonl(NFS4ERR_RESOURCE);
> + return htonl(status);
> +}
> +
> +static __be32 decode_offload_args(struct svc_rqst *rqstp,
> + struct xdr_stream *xdr,
> + struct cb_offloadargs *args)
> +{
> + __be32 status;
> +
> + status = decode_fh(xdr, &args->dst_fh);
> + if (unlikely(status != 0))
> + goto out;
> +
> + status = decode_stateid(xdr, &args->stateid);
> + if (unlikely(status != 0))
> + goto out;
> +
> + status = decode_write_res(xdr, &args->write_res);
> +out:
> + dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
> + return status;
> +}
> +#endif /* CONFIG_NFS_V4_2 */
> +
> static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
> {
> __be32 *p;
> @@ -794,9 +833,11 @@ preprocess_nfs42_op(int nop, unsigned int op_nr, struct callback_op **op)
> if (status != htonl(NFS4ERR_OP_ILLEGAL))
> return status;
>
> - if (op_nr == OP_CB_OFFLOAD)
> - return htonl(NFS4ERR_NOTSUPP);
> - return htonl(NFS4ERR_OP_ILLEGAL);
> + if (op_nr != OP_CB_OFFLOAD)
> + return htonl(NFS4ERR_OP_ILLEGAL);
> +
> + *op = &callback_ops[op_nr];
> + return htonl(NFS4_OK);
> }
> #else /* CONFIG_NFS_V4_2 */
> static __be32
> @@ -991,6 +1032,13 @@ static struct callback_op callback_ops[] = {
> .res_maxsize = CB_OP_RECALLSLOT_RES_MAXSZ,
> },
> #endif /* CONFIG_NFS_V4_1 */
> +#if defined(CONFIG_NFS_V4_2)
> + [OP_CB_OFFLOAD] = {
> + .process_op = (callback_process_op_t)nfs4_callback_offload,
> + .decode_args = (callback_decode_arg_t)decode_offload_args,
> + .res_maxsize = CB_OP_OFFLOAD_RES_MAXSZ,
> + },
> +#endif
> };
>
> /*
> diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
> index 26c7cf0..5c32fb5 100644
> --- a/fs/nfs/nfs4_fs.h
> +++ b/fs/nfs/nfs4_fs.h
> @@ -407,6 +407,9 @@ static inline void nfs4_unregister_sysctl(void)
>
> /* nfs4xdr.c */
> extern struct rpc_procinfo nfs4_procedures[];
> +#if defined(CONFIG_NFS_V4_2)
> +int decode_write_response(struct xdr_stream *, struct nfs42_write_response *);
> +#endif /* CONFIG_NFS_V4_2 */
>
> struct nfs4_mount_data;
>
> diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
> index ca77ab4..fbd5f77 100644
> --- a/fs/nfs/nfs4file.c
> +++ b/fs/nfs/nfs4file.c
> @@ -4,6 +4,7 @@
> * Copyright (C) 1992 Rick Sladkey
> */
> #include <linux/nfs_fs.h>
> +#include "callback.h"
> #include "internal.h"
> #include "fscache.h"
> #include "pnfs.h"
> @@ -118,6 +119,9 @@ nfs4_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
> }
>
> #ifdef CONFIG_NFS_V4_2
> +static LIST_HEAD(nfs_copy_async_list);
> +static DEFINE_SPINLOCK(async_copy_lock);
> +
> static int nfs4_find_copy_stateid(struct file *file, nfs4_stateid *stateid,
> fmode_t mode)
> {
> @@ -137,6 +141,43 @@ static int nfs4_find_copy_stateid(struct file *file, nfs4_stateid *stateid,
> return ret;
> }
>
> +static void wait_for_offload(struct nfs42_copy_res *res)
> +{
> + spin_lock(&async_copy_lock);
> + list_add(&res->wait_list, &nfs_copy_async_list);
> + spin_unlock(&async_copy_lock);
> +
> + wait_for_completion(&res->completion);
> +}
> +
> +static struct nfs42_copy_res *find_async_copy(nfs4_stateid *stateid)
> +{
> + struct nfs42_copy_res *cur;
> +
> + list_for_each_entry(cur, &nfs_copy_async_list, wait_list) {
> + if (memcmp(stateid, cur->cp_res.wr_stateid, sizeof(nfs4_stateid)) == 0)
> + return cur;
> + }
> + return NULL;
> +}
> +
> +void wake_copy_offload(struct cb_offloadargs *offload)
Please use a 'nfs_' prefix here to avoid namespace pollution. Ditto for
the above routines.
> +{
> + struct nfs42_copy_res *copy;
> +
> + spin_lock(&async_copy_lock);
> + copy = find_async_copy(&offload->stateid);
> + if (copy == NULL) {
> + spin_unlock(&async_copy_lock);
> + return;
> + }
> + list_del(©->wait_list);
Would it be better to have wait_for_offload() call list_del? That way,
you can make the completion interruptible.
> + spin_unlock(&async_copy_lock);
> +
> + copy->cp_res.wr_bytes_copied = offload->write_res.wr_bytes_copied;
> + complete(©->completion);
You might want to hold the async_copy_lock if the completion is
interruptible to prevent wait_for_offload() from doing list_del().
> +}
> +
> static ssize_t nfs4_copy_range(struct file *file_in, loff_t pos_in,
> struct file *file_out, loff_t pos_out,
> size_t count)
> @@ -159,10 +200,17 @@ static ssize_t nfs4_copy_range(struct file *file_in, loff_t pos_in,
> if (err)
> return err;
>
> + init_completion(&res.completion);
> +
> err = nfs42_proc_copy(NFS_SERVER(file_inode(file_out)), &args, &res);
> if (err)
> return err;
>
> + if (res.cp_res.wr_stateid != NULL) {
> + wait_for_offload(&res);
> + kfree(res.cp_res.wr_stateid);
> + }
> +
> return res.cp_res.wr_bytes_copied;
> }
> #endif /* CONFIG_NFS_V4_2 */
> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
> index d70c6bc..465d1bc 100644
> --- a/fs/nfs/nfs4xdr.c
> +++ b/fs/nfs/nfs4xdr.c
> @@ -6011,8 +6011,8 @@ out_overflow:
> #endif /* CONFIG_NFS_V4_1 */
>
> #ifdef CONFIG_NFS_V4_2
> -static int decode_write_response(struct xdr_stream *xdr,
> - struct nfs42_write_response *write_res)
> +int decode_write_response(struct xdr_stream *xdr,
> + struct nfs42_write_response *write_res)
> {
> __be32 *p;
> int num_ids;
> diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
> index 0bc6b14..f603793 100644
> --- a/include/linux/nfs_xdr.h
> +++ b/include/linux/nfs_xdr.h
> @@ -1231,6 +1231,9 @@ struct nfs42_copy_res {
> struct nfs4_sequence_res seq_res;
> unsigned int status;
> struct nfs42_write_response cp_res;
> +
> + struct list_head wait_list;
> + struct completion completion;
> };
> #endif
>
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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