From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE64A1E521 for ; Fri, 26 Jul 2024 13:54:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722002050; cv=none; b=jOpSOt6u53pWC37xDtBhbm9KxX0czwJ5+L/B04J6PvXoDVbMIqJiad70RI/IHDnGVZtA/p8RGvr/0eGtD3WNgQdMHoNDp6ENdhAt2UiitSS3nu4b6W74YbYet2ttT8SrwSbWda7CX2pE2OBTH/3Izou2NJ+JjbZe/HjyU7A/VAo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722002050; c=relaxed/simple; bh=UFgNUcpYgW4o7ZGGS3qHZ2uA3ZR6dmN7bRSfyKBELwI=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=NgWtv8przL0BKxwDxj7YmpyzUzyars5JS1cBDkghFVvbw20lx2aJBunlzkNAS1jUH6zuggEQo0yh+vzK6hBMy3P5Xt59CypQK1rXtZcmh8w8NuOPvI30RuWC0CQXOwTGisUNdaD2UNZ5kWTFDQiF69UWXSUsR0ih8JwkPIDpSJU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EjA9/ICh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EjA9/ICh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE9FBC32782; Fri, 26 Jul 2024 13:54:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722002050; bh=UFgNUcpYgW4o7ZGGS3qHZ2uA3ZR6dmN7bRSfyKBELwI=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=EjA9/IChVbgv6Y30SlmfzA6Gb+5E3ZEVI5Y1RPpg5/EFpOZ2YjSxEuZsOgBZL1zb8 P7JW4IIIzluCbZi96xhJinmarrBXxihKCX7DSWcTK1DrEkxEF32jzmbZJVZuGGMsDa 8wDV1TcwUEqhPmqAs++zmzQYRBYb5FF/rjDKWiQ2lZBEFtKmgTOVj/vYxYRvxiZJsZ HJIBAv8DugwU7kRYz/rXBNcBtCC/CeA0erNB297o8HWzAQRLLonjIt6Hm/722/R2HL vnaN4TwNVGYHRTXkr9iBCk4UQByyysmehCA1r5tq2Var01CCfYqCR52f8DqcdpNoAj jRzohiVvtimNw== Message-ID: <5d5df6d434189a19ca0be3d37cf1a2f4b7e60008.camel@kernel.org> Subject: Re: [PATCH rfc 2/2] NFSD: allow client to use write delegation stateid for READ From: Jeff Layton To: Sagi Grimberg , Chuck Lever Cc: Dai Ngo , linux-nfs@vger.kernel.org Date: Fri, 26 Jul 2024 09:54:08 -0400 In-Reply-To: <20240724170138.1942307-2-sagi@grimberg.me> References: <20240724170138.1942307-1-sagi@grimberg.me> <20240724170138.1942307-2-sagi@grimberg.me> Autocrypt: addr=jlayton@kernel.org; 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charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.4 (3.50.4-1.fc39) Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Wed, 2024-07-24 at 10:01 -0700, Sagi Grimberg wrote: > Based on a patch fom Dai Ngo, allow NFSv4 client to use write delegation > stateid for READ operation. Per RFC 8881 section 9.1.2. Use of the > Stateid and Locking. >=20 > In addition, for anonymous stateids, check for pending delegations by > the filehandle and client_id, and if a conflict found, recall the delegat= ion > before allowing the read to take place. >=20 > Suggested-by: Dai Ngo > Signed-off-by: Sagi Grimberg > --- > =C2=A0fs/nfsd/nfs4proc.c=C2=A0 | 22 +++++++++++++++++++-- > =C2=A0fs/nfsd/nfs4state.c | 47 ++++++++++++++++++++++++++++++++++++++++++= +++ > =C2=A0fs/nfsd/nfs4xdr.c=C2=A0=C2=A0 |=C2=A0 9 +++++++++ > =C2=A0fs/nfsd/state.h=C2=A0=C2=A0=C2=A0=C2=A0 |=C2=A0 2 ++ > =C2=A0fs/nfsd/xdr4.h=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 |=C2=A0 2 ++ > =C2=A05 files changed, 80 insertions(+), 2 deletions(-) >=20 > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > index 7b70309ad8fb..324984ec70c6 100644 > --- a/fs/nfsd/nfs4proc.c > +++ b/fs/nfsd/nfs4proc.c > @@ -979,8 +979,24 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_comp= ound_state *cstate, > =C2=A0 /* check stateid */ > =C2=A0 status =3D nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->curr= ent_fh, > =C2=A0 &read->rd_stateid, RD_STATE, > - &read->rd_nf, NULL); > - > + &read->rd_nf, &read->rd_wd_stid); In the case where we have multiple stateids for this client, are we guaranteed to get back the delegation stateid here? What if we get back the open stateid for the O_WRONLY open instead? > + /* > + * rd_wd_stid is needed for nfsd4_encode_read to allow write > + * delegation stateid used for read. Its refcount is decremented > + * by nfsd4_read_release when read is done. > + */ > + if (!status) { > + if (!read->rd_wd_stid) { > + /* special stateid? */ > + status =3D nfsd4_deleg_read_conflict(rqstp, cstate->clp, > + &cstate->current_fh); > + } else if (read->rd_wd_stid->sc_type !=3D SC_TYPE_DELEG || > + =C2=A0=C2=A0 delegstateid(read->rd_wd_stid)->dl_type !=3D > + NFS4_OPEN_DELEGATE_WRITE) { > + nfs4_put_stid(read->rd_wd_stid); > + read->rd_wd_stid =3D NULL; > + } > + } > =C2=A0 read->rd_rqstp =3D rqstp; > =C2=A0 read->rd_fhp =3D &cstate->current_fh; > =C2=A0 return status; > @@ -990,6 +1006,8 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_comp= ound_state *cstate, > =C2=A0static void > =C2=A0nfsd4_read_release(union nfsd4_op_u *u) > =C2=A0{ > + if (u->read.rd_wd_stid) > + nfs4_put_stid(u->read.rd_wd_stid); > =C2=A0 if (u->read.rd_nf) > =C2=A0 nfsd_file_put(u->read.rd_nf); > =C2=A0 trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp, > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index dc61a8adfcd4..7e6b9fb31a4c 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -8805,6 +8805,53 @@ nfsd4_get_writestateid(struct nfsd4_compound_state= *cstate, > =C2=A0 get_stateid(cstate, &u->write.wr_stateid); > =C2=A0} > =C2=A0 > +/** > + * nfsd4_deleg_read_conflict - Recall if read causes conflict > + * @rqstp: RPC transaction context > + * @clp: nfs client > + * @fhp: nfs file handle > + * @inode: file to be checked for a conflict > + * @modified: return true if file was modified > + * @size: new size of file if modified is true > + * > + * This function is called when there is a conflict between a write > + * delegation and a read that is using a special stateid where the > + * we cannot derive the client stateid exsistence. The server > + * must recall a conflicting delegation before allowing the read > + * to continue. > + * > + * Returns 0 if there is no conflict; otherwise an nfs_stat > + * code is returned. > + */ > +__be32 nfsd4_deleg_read_conflict(struct svc_rqst *rqstp, > + struct nfs4_client *clp, struct svc_fh *fhp) > +{ > + struct nfs4_file *fp; > + __be32 status =3D 0; > + > + fp =3D nfsd4_file_hash_lookup(fhp); > + if (!fp) > + return nfs_ok; > + > + spin_lock(&state_lock); > + spin_lock(&fp->fi_lock); > + if (!list_empty(&fp->fi_delegations) && > + =C2=A0=C2=A0=C2=A0 !nfs4_delegation_exists(clp, fp)) { > + /* conflict, recall deleg */ > + status =3D nfserrno(nfsd_open_break_lease(fp->fi_inode, > + NFSD_MAY_READ)); > + if (status) > + goto out; > + if (!nfsd_wait_for_delegreturn(rqstp, fp->fi_inode)) > + status =3D nfserr_jukebox; > + } > +out: > + spin_unlock(&fp->fi_lock); > + spin_unlock(&state_lock); > + return status; > +} > + > + > =C2=A0/** > =C2=A0 * nfsd4_deleg_getattr_conflict - Recall if GETATTR causes conflict > =C2=A0 * @rqstp: RPC transaction context > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > index c7bfd2180e3f..f0fe526fac3c 100644 > --- a/fs/nfsd/nfs4xdr.c > +++ b/fs/nfsd/nfs4xdr.c > @@ -4418,6 +4418,7 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, _= _be32 nfserr, > =C2=A0 unsigned long maxcount; > =C2=A0 struct file *file; > =C2=A0 __be32 *p; > + fmode_t o_fmode =3D 0; > =C2=A0 > =C2=A0 if (nfserr) > =C2=A0 return nfserr; > @@ -4437,10 +4438,18 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp,= __be32 nfserr, > =C2=A0 maxcount =3D min_t(unsigned long, read->rd_length, > =C2=A0 (xdr->buf->buflen - xdr->buf->len)); > =C2=A0 > + if (read->rd_wd_stid) { > + /* allow READ using write delegation stateid */ > + o_fmode =3D file->f_mode; > + file->f_mode |=3D FMODE_READ; > + } > =C2=A0 if (file->f_op->splice_read && splice_ok) > =C2=A0 nfserr =3D nfsd4_encode_splice_read(resp, read, file, maxcount); > =C2=A0 else > =C2=A0 nfserr =3D nfsd4_encode_readv(resp, read, file, maxcount); > + if (o_fmode) > + file->f_mode =3D o_fmode; > + > =C2=A0 if (nfserr) { > =C2=A0 xdr_truncate_encode(xdr, starting_len); > =C2=A0 return nfserr; > diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h > index ffc217099d19..c1f13b5877c6 100644 > --- a/fs/nfsd/state.h > +++ b/fs/nfsd/state.h > @@ -780,6 +780,8 @@ static inline bool try_to_expire_client(struct nfs4_c= lient *clp) > =C2=A0 return clp->cl_state =3D=3D NFSD4_EXPIRABLE; > =C2=A0} > =C2=A0 > +extern __be32 nfsd4_deleg_read_conflict(struct svc_rqst *rqstp, > + struct nfs4_client *clp, struct svc_fh *fhp); > =C2=A0extern __be32 nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp, > =C2=A0 struct inode *inode, bool *file_modified, u64 *size); > =C2=A0#endif=C2=A0=C2=A0 /* NFSD4_STATE_H */ > diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h > index fbdd42cde1fa..434973a6a8b1 100644 > --- a/fs/nfsd/xdr4.h > +++ b/fs/nfsd/xdr4.h > @@ -426,6 +426,8 @@ struct nfsd4_read { > =C2=A0 struct svc_rqst *rd_rqstp;=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0 /* response */ > =C2=A0 struct svc_fh *rd_fhp;=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0=C2=A0 /* response */ > =C2=A0 u32 rd_eof;=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0 /* response */ > + > + struct nfs4_stid *rd_wd_stid; /* internal */ > =C2=A0}; > =C2=A0 > =C2=A0struct nfsd4_readdir { --=20 Jeff Layton