Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:48010 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935458AbaH0TfR (ORCPT ); Wed, 27 Aug 2014 15:35:17 -0400 Date: Wed, 27 Aug 2014 15:35:16 -0400 From: "J. Bruce Fields" To: Anna Schumaker Cc: bjschuma@netapp.com, linux-nfs@vger.kernel.org Subject: Re: [PATCH 3/3] NFSD: Implement SEEK Message-ID: <20140827193515.GF13910@fieldses.org> References: <1409152678-7806-1-git-send-email-bjschuma@netapp.com> <1409152678-7806-4-git-send-email-bjschuma@netapp.com> <20140827190940.GD13910@fieldses.org> <53FE2FB2.3040606@Netapp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <53FE2FB2.3040606@Netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Aug 27, 2014 at 03:21:22PM -0400, Anna Schumaker wrote: > On 08/27/2014 03:09 PM, J. Bruce Fields wrote: > > On Wed, Aug 27, 2014 at 11:17:58AM -0400, bjschuma@netapp.com wrote: > >> From: Anna Schumaker > >> > >> This patch adds server support for the NFS v4.2 operation SEEK, which > >> returns the position of the next hole or data segment in a file. This > >> operation is off by default, and needs CONFIG_NFSD_V4_2_SEEK=y to be > >> compiled. > >> > >> Signed-off-by: Anna Schumaker > >> --- > >> fs/nfsd/Kconfig | 12 ++++++++++++ > >> fs/nfsd/nfs4proc.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ > >> fs/nfsd/nfs4xdr.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ > >> fs/nfsd/xdr4.h | 14 ++++++++++++++ > >> include/linux/nfs4.h | 5 +++++ > >> 5 files changed, 123 insertions(+) > >> > >> diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig > >> index f994e75..804b20a 100644 > >> --- a/fs/nfsd/Kconfig > >> +++ b/fs/nfsd/Kconfig > >> @@ -81,6 +81,18 @@ config NFSD_V4 > >> > >> If unsure, say N. > >> > >> +config NFSD_V4_2_SEEK > >> + bool "Enable SEEK support for the NFS v4.2 server" > >> + depends on NFSD_V4 > >> + help > >> + Say Y here if you want to enable support for the NFS v4.2 operation > >> + SEEK, which adds in SEEK_HOLE and SEEK_DATA support. > >> + > >> + WARNING: there is still a chance of backwards-incompatible protocol > >> + changes. This feature is targeted at developers and testers only. > > > > I think now that we should instead confirm with the working group that > > backwards-incompatible changes are done, and skip this warning. > > > > I'll remove it in the labeled NFS case, which we've decided is "done" > > even if the rest of the 4.2 draft isn't. > > > > I also wonder if we should ditch these configuration options, or keep > > them only temporarily. It's not much code, so I think the only reason > > to allow configuring it out is to temporarily protect people from > > immature code. > > I was expecting them to be temporary, and to get removed when the draft becomes an RFC. OK. In the security label case I guess there's one other issue, which is that removing CONFIG_NFSD_V4_SECURITY_LABEL would mean adding a previously unnecessary dependency on CONFIG_SECURITY. --b. > > > > >> + > >> + 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 5e0dc52..f555eb2 100644 > >> --- a/fs/nfsd/nfs4proc.c > >> +++ b/fs/nfsd/nfs4proc.c > >> @@ -1013,6 +1013,45 @@ nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > >> return status; > >> } > >> > >> +#ifdef CONFIG_NFSD_V4_2_SEEK > >> +static __be32 > >> +nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > >> + struct nfsd4_seek *seek) > >> +{ > >> + struct file *file; > >> + __be32 status = nfs_ok; > >> + > >> + status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate, > >> + &seek->seek_stateid, > >> + RD_STATE | WR_STATE, &file); > > > > I think that should be just RD_STATE. > > I was trying to cover the case where an application does: > > open(WRITE); > seek(HOLE); > write("blah"); > > I can change the code if that's not the way people use SEEK_HOLE / SEEK_DATA ... > > Anna > > > > > --b. > > > > > >> + if (status) { > >> + dprintk("NFSD: nfsd4_seek: couldn't process stateid!\n"); > >> + return status; > >> + } > >> + > >> + switch (seek->seek_whence) { > >> + case NFS4_CONTENT_DATA: > >> + seek->seek_pos = vfs_llseek(file, seek->seek_offset, SEEK_DATA); > >> + break; > >> + case NFS4_CONTENT_HOLE: > >> + seek->seek_pos = vfs_llseek(file, seek->seek_offset, SEEK_HOLE); > >> + break; > >> + default: > >> + status = nfserr_union_notsupp; > >> + goto out; > >> + } > >> + > >> + if (seek->seek_pos < 0) > >> + status = nfserrno(seek->seek_pos); > >> + else if (seek->seek_pos >= i_size_read(file_inode(file))) > >> + seek->seek_eof = true; > >> + > >> +out: > >> + fput(file); > >> + return status; > >> +} > >> +#endif /* CONFIG_NFSD_V4_2_SEEK */ > >> + > >> /* This routine never returns NFS_OK! If there are no other errors, it > >> * will return NFSERR_SAME or NFSERR_NOT_SAME depending on whether the > >> * attributes matched. VERIFY is implemented by mapping NFSERR_SAME > >> @@ -1881,6 +1920,14 @@ static struct nfsd4_operation nfsd4_ops[] = { > >> .op_get_currentstateid = (stateid_getter)nfsd4_get_freestateid, > >> .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize, > >> }, > >> + > >> + /* NFSv4.2 operations */ > >> +#ifdef CONFIG_NFSD_V4_2_SEEK > >> + [OP_SEEK] = { > >> + .op_func = (nfsd4op_func)nfsd4_seek, > >> + .op_name = "OP_SEEK", > >> + }, > >> +#endif /* CONFIG_NFSD_V4_2_SEEK */ > >> }; > >> > >> int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op) > >> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > >> index 94dde7b..5bedeb3 100644 > >> --- a/fs/nfsd/nfs4xdr.c > >> +++ b/fs/nfsd/nfs4xdr.c > >> @@ -1520,6 +1520,24 @@ static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, str > >> DECODE_TAIL; > >> } > >> > >> +#ifdef CONFIG_NFSD_V4_2_SEEK > >> +static __be32 > >> +nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek) > >> +{ > >> + DECODE_HEAD; > >> + > >> + status = nfsd4_decode_stateid(argp, &seek->seek_stateid); > >> + if (status) > >> + return status; > >> + > >> + READ_BUF(12); > >> + p = xdr_decode_hyper(p, &seek->seek_offset); > >> + seek->seek_whence = be32_to_cpup(p); > >> + > >> + DECODE_TAIL; > >> +} > >> +#endif /* CONFIG_NFSD_V4_2_SEEK */ > >> + > >> static __be32 > >> nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p) > >> { > >> @@ -1605,7 +1623,11 @@ static nfsd4_dec nfsd4_dec_ops[] = { > >> [OP_OFFLOAD_CANCEL] = (nfsd4_dec)nfsd4_decode_notsupp, > >> [OP_OFFLOAD_STATUS] = (nfsd4_dec)nfsd4_decode_notsupp, > >> [OP_READ_PLUS] = (nfsd4_dec)nfsd4_decode_notsupp, > >> +#ifdef CONFIG_NFSD_V4_2_SEEK > >> + [OP_SEEK] = (nfsd4_dec)nfsd4_decode_seek, > >> +#else > >> [OP_SEEK] = (nfsd4_dec)nfsd4_decode_notsupp, > >> +#endif /* CONFIG_NFSD_V4_2_SEEK */ > >> [OP_WRITE_SAME] = (nfsd4_dec)nfsd4_decode_notsupp, > >> }; > >> > >> @@ -3764,6 +3786,24 @@ nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr, > >> return nfserr; > >> } > >> > >> +#ifdef CONFIG_NFSD_V4_2_SEEK > >> +static __be32 > >> +nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr, > >> + struct nfsd4_seek *seek) > >> +{ > >> + __be32 *p; > >> + > >> + if (nfserr) > >> + return nfserr; > >> + > >> + p = xdr_reserve_space(&resp->xdr, 12); > >> + *p++ = cpu_to_be32(seek->seek_eof); > >> + p = xdr_encode_hyper(p, seek->seek_pos); > >> + > >> + return nfserr; > >> +} > >> +#endif /* CONFIG_NFSD_V4_2_SEEK */ > >> + > >> static __be32 > >> nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p) > >> { > >> @@ -3848,8 +3888,13 @@ static nfsd4_enc nfsd4_enc_ops[] = { > >> [OP_OFFLOAD_CANCEL] = (nfsd4_enc)nfsd4_encode_noop, > >> [OP_OFFLOAD_STATUS] = (nfsd4_enc)nfsd4_encode_noop, > >> [OP_READ_PLUS] = (nfsd4_enc)nfsd4_encode_noop, > >> +#ifdef CONFIG_NFSD_V4_2_SEEK > >> + [OP_SEEK] = (nfsd4_enc)nfsd4_encode_seek, > >> +#else > >> [OP_SEEK] = (nfsd4_enc)nfsd4_encode_noop, > >> +#endif /* CONFIG_NFSD_V4_2_SEEK */ > >> [OP_WRITE_SAME] = (nfsd4_enc)nfsd4_encode_noop, > >> + [OP_IO_ADVISE] = (nfsd4_enc)nfsd4_encode_noop, > >> }; > >> > >> /* > >> diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h > >> index 465e779..5720e94 100644 > >> --- a/fs/nfsd/xdr4.h > >> +++ b/fs/nfsd/xdr4.h > >> @@ -428,6 +428,17 @@ struct nfsd4_reclaim_complete { > >> u32 rca_one_fs; > >> }; > >> > >> +struct nfsd4_seek { > >> + /* request */ > >> + stateid_t seek_stateid; > >> + loff_t seek_offset; > >> + u32 seek_whence; > >> + > >> + /* response */ > >> + u32 seek_eof; > >> + loff_t seek_pos; > >> +}; > >> + > >> struct nfsd4_op { > >> int opnum; > >> __be32 status; > >> @@ -473,6 +484,9 @@ struct nfsd4_op { > >> struct nfsd4_reclaim_complete reclaim_complete; > >> struct nfsd4_test_stateid test_stateid; > >> struct nfsd4_free_stateid free_stateid; > >> + > >> + /* NFSv4.2 */ > >> + struct nfsd4_seek seek; > >> } u; > >> struct nfs4_replay * replay; > >> }; > >> diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h > >> index cf38224..026b0c0 100644 > >> --- a/include/linux/nfs4.h > >> +++ b/include/linux/nfs4.h > >> @@ -550,4 +550,9 @@ struct nfs4_deviceid { > >> char data[NFS4_DEVICEID4_SIZE]; > >> }; > >> > >> +enum data_content4 { > >> + NFS4_CONTENT_DATA = 0, > >> + NFS4_CONTENT_HOLE = 1, > >> +}; > >> + > >> #endif > >> -- > >> 2.1.0 > >> >