Re: [PATCH v2 09/10] NFSD: allow inter server COPY to have a STALE source server fh

[Olga Kornievskaia <olga.kornievskaia@gmail.com>]

On Fri, Nov 30, 2018 at 3:04 PM Olga Kornievskaia
<olga.kornievskaia@gmail.com> wrote:
>
> The inter server to server COPY source server filehandle
> is a foreign filehandle as the COPY is sent to the destination
> server.
>
> Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> ---
>  fs/nfsd/Kconfig    | 10 ++++++++++
>  fs/nfsd/nfs4proc.c | 41 ++++++++++++++++++++++++++++++++++++-----
>  fs/nfsd/nfsfh.h    |  5 ++++-
>  fs/nfsd/xdr4.h     |  1 +
>  4 files changed, 51 insertions(+), 6 deletions(-)
>
> diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
> index 20b1c17..37ff3d5 100644
> --- a/fs/nfsd/Kconfig
> +++ b/fs/nfsd/Kconfig
> @@ -131,6 +131,16 @@ config NFSD_FLEXFILELAYOUT
>
>           If unsure, say N.
>
> +config NFSD_V4_2_INTER_SSC
> +       bool "NFSv4.2 inter server to server COPY"
> +       depends on NFSD_V4 && NFS_V4_1 && NFS_V4_2
> +       help
> +         This option enables support for NFSv4.2 inter server to
> +         server copy where the destination server calls the NFSv4.2
> +         client to read the data to copy from the source server.
> +
> +         If unsure, say N.
> +
>  config NFSD_V4_SECURITY_LABEL
>         bool "Provide Security Label support for NFSv4 server"
>         depends on NFSD_V4 && SECURITY
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index 70d03e9..2e28254 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -503,12 +503,20 @@ static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_stat
>             union nfsd4_op_u *u)
>  {
>         struct nfsd4_putfh *putfh = &u->putfh;
> +       __be32 ret;
>
>         fh_put(&cstate->current_fh);
>         cstate->current_fh.fh_handle.fh_size = putfh->pf_fhlen;
>         memcpy(&cstate->current_fh.fh_handle.fh_base, putfh->pf_fhval,
>                putfh->pf_fhlen);
> -       return fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_BYPASS_GSS);
> +       ret = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_BYPASS_GSS);
> +#ifdef CONFIG_NFSD_V4_2_INTER_SSC
> +       if (ret == nfserr_stale && putfh->no_verify) {
> +               SET_FH_FLAG(&cstate->current_fh, NFSD4_FH_FOREIGN);
> +               ret = 0;
> +       }
> +#endif
> +       return ret;
>  }
>
>  static __be32
> @@ -1967,11 +1975,12 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
>  {
>         struct nfsd4_compoundargs *args = rqstp->rq_argp;
>         struct nfsd4_compoundres *resp = rqstp->rq_resp;
> -       struct nfsd4_op *op;
> +       struct nfsd4_op *op, *current_op, *saved_op;
>         struct nfsd4_compound_state *cstate = &resp->cstate;
>         struct svc_fh *current_fh = &cstate->current_fh;
>         struct svc_fh *save_fh = &cstate->save_fh;
>         __be32          status;
> +       int i;
>
>         svcxdr_init_encode(rqstp, resp);
>         resp->tagp = resp->xdr.p;
> @@ -2006,6 +2015,27 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
>                 resp->opcnt = 1;
>                 goto encode_op;
>         }
> +#ifdef CONFIG_NFSD_V4_2_INTER_SSC
> +       /* traverse all operation and if it's a COPY compound, mark the
> +        * source filehandle to skip verification
> +        */
> +       for (i = 0; i < args->opcnt; i++) {
> +               op = &args->ops[i];
> +               if (op->opnum == OP_PUTFH)
> +                       current_op = op;
> +               else if (op->opnum == OP_SAVEFH)
> +                       saved_op = current_op;
> +               else if (op->opnum == OP_RESTOREFH)
> +                       current_op = saved_op;
> +               else if (op->opnum == OP_COPY) {
> +                       struct nfsd4_copy *copy = (struct nfsd4_copy *)&op[i].u;

Bruce, found an error this needs to be  "op.u" not "op[i]".

> +                       struct nfsd4_putfh *putfh =
> +                               (struct nfsd4_putfh *)&saved_op->u;
> +                       if (!copy->cp_intra)
> +                               putfh->no_verify = true;
> +               }
> +       }
> +#endif
>
>         trace_nfsd_compound(rqstp, args->opcnt);
>         while (!status && resp->opcnt < args->opcnt) {
> @@ -2021,13 +2051,14 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
>                                 op->status = nfsd4_open_omfg(rqstp, cstate, op);
>                         goto encode_op;
>                 }
> -
> -               if (!current_fh->fh_dentry) {
> +               if (!current_fh->fh_dentry &&
> +                               !HAS_FH_FLAG(current_fh, NFSD4_FH_FOREIGN)) {
>                         if (!(op->opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
>                                 op->status = nfserr_nofilehandle;
>                                 goto encode_op;
>                         }
> -               } else if (current_fh->fh_export->ex_fslocs.migrated &&
> +               } else if (current_fh->fh_export &&
> +                          current_fh->fh_export->ex_fslocs.migrated &&
>                           !(op->opdesc->op_flags & ALLOWED_ON_ABSENT_FS)) {
>                         op->status = nfserr_moved;
>                         goto encode_op;
> diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h
> index 755e256..b9c7568 100644
> --- a/fs/nfsd/nfsfh.h
> +++ b/fs/nfsd/nfsfh.h
> @@ -35,7 +35,7 @@ static inline ino_t u32_to_ino_t(__u32 uino)
>
>         bool                    fh_locked;      /* inode locked by us */
>         bool                    fh_want_write;  /* remount protection taken */
> -
> +       int                     fh_flags;       /* FH flags */
>  #ifdef CONFIG_NFSD_V3
>         bool                    fh_post_saved;  /* post-op attrs saved */
>         bool                    fh_pre_saved;   /* pre-op attrs saved */
> @@ -56,6 +56,9 @@ static inline ino_t u32_to_ino_t(__u32 uino)
>  #endif /* CONFIG_NFSD_V3 */
>
>  } svc_fh;
> +#define NFSD4_FH_FOREIGN (1<<0)
> +#define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f))
> +#define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f))
>
>  enum nfsd_fsid {
>         FSID_DEV = 0,
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index 9d7318c..fbd18d6 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -221,6 +221,7 @@ struct nfsd4_lookup {
>  struct nfsd4_putfh {
>         u32             pf_fhlen;           /* request */
>         char            *pf_fhval;          /* request */
> +       bool            no_verify;          /* represents foreigh fh */
>  };
>
>  struct nfsd4_open {
> --
> 1.8.3.1
>