On Thu, Mar 02, 2017 at 11:01:28AM -0500, Olga Kornievskaia wrote:
> From: Andy Adamson <andros@xxxxxxxxxx>
>
> The inter server to server COPY source server filehandle
> is guaranteed to be stale as the COPY is sent to the destination
> server.
This is definitely not true. That filehandle could very well mean
something to the source server, even if it's just by accident.
In the case the source filehandle refers to a file on a different
server, nfsd knows that, and should not call fh_verify on it at all.
--b.
>
> Signed-off-by: Andy Adamson <andros@xxxxxxxxxx>
> ---
> fs/nfsd/nfs4proc.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
> fs/nfsd/nfs4xdr.c | 26 +++++++++++++++++++++++++-
> fs/nfsd/nfsd.h | 2 ++
> fs/nfsd/xdr4.h | 4 ++++
> 4 files changed, 77 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index a680c8c..733a9aa 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -496,11 +496,19 @@ static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_stat
> nfsd4_putfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> struct nfsd4_putfh *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);
> + if (ret == nfserr_stale && HAS_CSTATE_FLAG(cstate, NO_VERIFY_FH)) {
> + CLEAR_CSTATE_FLAG(cstate, NO_VERIFY_FH);
> + SET_CSTATE_FLAG(cstate, IS_STALE_FH);
> + ret = 0;
> + }
> + return ret;
> }
>
> static __be32
> @@ -533,6 +541,16 @@ static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_stat
> nfsd4_savefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> void *arg)
> {
> + /**
> + * This is either an inter COPY (most likely) or an intra COPY with a
> + * stale file handle. If the latter, nfsd4_copy will reset the PUTFH to
> + * return nfserr_stale. No fh_dentry, just copy the file handle
> + * to use with the inter COPY READ.
> + */
> + if (HAS_CSTATE_FLAG(cstate, IS_STALE_FH)) {
> + cstate->save_fh = cstate->current_fh;
> + return nfs_ok;
> + }
> if (!cstate->current_fh.fh_dentry)
> return nfserr_nofilehandle;
>
> @@ -1067,6 +1085,13 @@ static int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write)
> if (status)
> goto out;
>
> + /* Intra copy source fh is stale. PUTFH will fail with ESTALE */
> + if (HAS_CSTATE_FLAG(cstate, IS_STALE_FH)) {
> + CLEAR_CSTATE_FLAG(cstate, IS_STALE_FH);
> + cstate->status = nfserr_copy_stalefh;
> + goto out_put;
> + }
> +
> bytes = nfsd_copy_file_range(src, copy->cp_src_pos,
> dst, copy->cp_dst_pos, copy->cp_count);
>
> @@ -1081,6 +1106,7 @@ static int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write)
> status = nfs_ok;
> }
>
> +out_put:
> fput(src);
> fput(dst);
> out:
> @@ -1776,6 +1802,7 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
> struct nfsd4_compound_state *cstate = &resp->cstate;
> struct svc_fh *current_fh = &cstate->current_fh;
> struct svc_fh *save_fh = &cstate->save_fh;
> + int i;
> __be32 status;
>
> svcxdr_init_encode(rqstp, resp);
> @@ -1808,6 +1835,12 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
> goto encode_op;
> }
>
> + /* NFSv4.2 COPY source file handle may be from a different server */
> + for (i = 0; i < args->opcnt; i++) {
> + op = &args->ops[i];
> + if (op->opnum == OP_COPY)
> + SET_CSTATE_FLAG(cstate, NO_VERIFY_FH);
> + }
> while (!status && resp->opcnt < args->opcnt) {
> op = &args->ops[resp->opcnt++];
>
> @@ -1827,6 +1860,9 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
>
> opdesc = OPDESC(op);
>
> + if (HAS_CSTATE_FLAG(cstate, IS_STALE_FH))
> + goto call_op;
> +
> if (!current_fh->fh_dentry) {
> if (!(opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
> op->status = nfserr_nofilehandle;
> @@ -1861,6 +1897,7 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
>
> if (opdesc->op_get_currentstateid)
> opdesc->op_get_currentstateid(cstate, &op->u);
> +call_op:
> op->status = opdesc->op_func(rqstp, cstate, &op->u);
>
> if (!op->status) {
> @@ -1881,6 +1918,14 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
> status = op->status;
> goto out;
> }
> + /* Only from intra COPY */
> + if (cstate->status == nfserr_copy_stalefh) {
> + dprintk("%s NFS4.2 intra COPY stale src filehandle\n",
> + __func__);
> + status = nfserr_stale;
> + nfsd4_adjust_encode(resp);
> + goto out;
> + }
> if (op->status == nfserr_replay_me) {
> op->replay = &cstate->replay_owner->so_replay;
> nfsd4_encode_replay(&resp->xdr, op);
> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
> index c632156..328ff9c 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -4619,15 +4619,28 @@ __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
> return nfserr_rep_too_big;
> }
>
> +/** Rewind the encoding to return nfserr_stale on the PUTFH
> + * in this failed Intra COPY compound
> + */
> +void
> +nfsd4_adjust_encode(struct nfsd4_compoundres *resp)
> +{
> + __be32 *p;
> +
> + p = resp->cstate.putfh_errp;
> + *p++ = nfserr_stale;
> +}
> +
> void
> nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
> {
> struct xdr_stream *xdr = &resp->xdr;
> struct nfs4_stateowner *so = resp->cstate.replay_owner;
> + struct nfsd4_compound_state *cstate = &resp->cstate;
> struct svc_rqst *rqstp = resp->rqstp;
> int post_err_offset;
> nfsd4_enc encoder;
> - __be32 *p;
> + __be32 *p, *statp;
>
> p = xdr_reserve_space(xdr, 8);
> if (!p) {
> @@ -4636,9 +4649,20 @@ __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
> }
> *p++ = cpu_to_be32(op->opnum);
> post_err_offset = xdr->buf->len;
> + statp = p;
>
> if (op->opnum == OP_ILLEGAL)
> goto status;
> +
> + /** This is a COPY compound with a stale source server file handle.
> + * If OP_COPY processing determines that this is an intra server to
> + * server COPY, then this PUTFH should return nfserr_ stale so the
> + * putfh_errp will be set to nfserr_stale. If this is an inter server
> + * to server COPY, ignore the nfserr_stale.
> + */
> + if (op->opnum == OP_PUTFH && HAS_CSTATE_FLAG(cstate, IS_STALE_FH))
> + cstate->putfh_errp = statp;
> +
> BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
> !nfsd4_enc_ops[op->opnum]);
> encoder = nfsd4_enc_ops[op->opnum];
> diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
> index d966068..8d6fb0f 100644
> --- a/fs/nfsd/nfsd.h
> +++ b/fs/nfsd/nfsd.h
> @@ -272,6 +272,8 @@ static inline bool nfsd4_spo_must_allow(struct svc_rqst *rqstp)
> #define nfserr_replay_me cpu_to_be32(11001)
> /* nfs41 replay detected */
> #define nfserr_replay_cache cpu_to_be32(11002)
> +/* nfs42 intra copy failed with nfserr_stale */
> +#define nfserr_copy_stalefh cpu_to_be32(1103)
>
> /* Check for dir entries '.' and '..' */
> #define isdotent(n, l) (l < 3 && n[0] == '.' && (l == 1 || n[1] == '.'))
> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
> index 38fcb4f..aa94295 100644
> --- a/fs/nfsd/xdr4.h
> +++ b/fs/nfsd/xdr4.h
> @@ -45,6 +45,8 @@
>
> #define CURRENT_STATE_ID_FLAG (1<<0)
> #define SAVED_STATE_ID_FLAG (1<<1)
> +#define NO_VERIFY_FH (1<<2)
> +#define IS_STALE_FH (1<<3)
>
> #define SET_CSTATE_FLAG(c, f) ((c)->sid_flags |= (f))
> #define HAS_CSTATE_FLAG(c, f) ((c)->sid_flags & (f))
> @@ -63,6 +65,7 @@ struct nfsd4_compound_state {
> size_t iovlen;
> u32 minorversion;
> __be32 status;
> + __be32 *putfh_errp;
> stateid_t current_stateid;
> stateid_t save_stateid;
> /* to indicate current and saved state id presents */
> @@ -705,6 +708,7 @@ int nfs4svc_decode_compoundargs(struct svc_rqst *, __be32 *,
> int nfs4svc_encode_compoundres(struct svc_rqst *, __be32 *,
> struct nfsd4_compoundres *);
> __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *, u32);
> +void nfsd4_adjust_encode(struct nfsd4_compoundres *);
> void nfsd4_encode_operation(struct nfsd4_compoundres *, struct nfsd4_op *);
> void nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op);
> __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
> --
> 1.8.3.1
>
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