Return-Path: Received: from userp2130.oracle.com ([156.151.31.86]:46868 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751862AbeC0Q5X (ORCPT ); Tue, 27 Mar 2018 12:57:23 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.2 \(3445.5.20\)) Subject: Re: [PATCH v2 15/18] nfsd: Add I/O trace points in the NFSv4 read proc From: Chuck Lever In-Reply-To: <20180327145340.7710.93006.stgit@oracle-ib-101.nfsv4bat.org> Date: Tue, 27 Mar 2018 12:57:17 -0400 Cc: Linux NFS Mailing List Message-Id: <97BBDD8C-AE6F-480B-8C6A-A98B2CDF9E10@oracle.com> References: <20180327144420.7710.82288.stgit@oracle-ib-101.nfsv4bat.org> <20180327145340.7710.93006.stgit@oracle-ib-101.nfsv4bat.org> To: Bruce Fields Sender: linux-nfs-owner@vger.kernel.org List-ID: > On Mar 27, 2018, at 10:53 AM, Chuck Lever = wrote: >=20 > NFSv4 read compound processing invokes nfsd_splice_read and > nfs_readv directly, so the trace points currently in nfsd_read are > not effective for NFSv4 reads. >=20 > Move and copy the trace points so that NFSv4 reads are captured. > Also, we want to record any local I/O error that occurs, and > the total count of bytes that were actually moved. And, also > whether splice or vectored read was used. >=20 > The svc_fh is not passed to the read helpers, so some code > duplication is necessary. >=20 > Signed-off-by: Chuck Lever > --- > fs/nfsd/nfs4proc.c | 5 +++++ > fs/nfsd/nfs4xdr.c | 56 = +++++++++++++++++++++++++++++++++++++--------------- > fs/nfsd/trace.h | 4 +++- > fs/nfsd/vfs.c | 54 = ++++++++++++++++++++++---------------------------- > fs/nfsd/vfs.h | 8 ++++--- > 5 files changed, 76 insertions(+), 51 deletions(-) >=20 > diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > index b93673e..39016b6 100644 > --- a/fs/nfsd/nfs4proc.c > +++ b/fs/nfsd/nfs4proc.c > @@ -751,6 +751,9 @@ static __be32 nfsd4_do_lookupp(struct svc_rqst = *rqstp, struct svc_fh *fh) > if (read->rd_offset >=3D OFFSET_MAX) > return nfserr_inval; >=20 > + trace_nfsd_read_start(rqstp, &cstate->current_fh, > + read->rd_offset, read->rd_length); > + > /* > * If we do a zero copy read, then a client will see read data > * that reflects the state of the file *after* performing the > @@ -783,6 +786,8 @@ static __be32 nfsd4_do_lookupp(struct svc_rqst = *rqstp, struct svc_fh *fh) > { > if (u->read.rd_filp) > fput(u->read.rd_filp); > + trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp, > + u->read.rd_offset, u->read.rd_length); > } >=20 > static __be32 > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > index e502fd1..d03059a 100644 > --- a/fs/nfsd/nfs4xdr.c > +++ b/fs/nfsd/nfs4xdr.c > @@ -37,6 +37,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -50,6 +51,7 @@ > #include "cache.h" > #include "netns.h" > #include "pnfs.h" > +#include "trace.h" >=20 > #ifdef CONFIG_NFSD_V4_SECURITY_LABEL > #include > @@ -3416,28 +3418,28 @@ static __be32 nfsd4_encode_splice_read( > { > struct xdr_stream *xdr =3D &resp->xdr; > struct xdr_buf *buf =3D xdr->buf; > + int host_err; > u32 eof; > long len; > int space_left; > - __be32 nfserr; > __be32 *p =3D xdr->p - 2; >=20 > /* Make sure there will be room for padding if needed */ > if (xdr->end - xdr->p < 1) > return nfserr_resource; >=20 > + trace_nfsd_read_splice(resp->rqstp, read->rd_fhp, > + read->rd_offset, maxcount); > len =3D maxcount; > - nfserr =3D nfsd_splice_read(read->rd_rqstp, file, > + host_err =3D nfsd_splice_read(read->rd_rqstp, file, > read->rd_offset, &maxcount); > - if (nfserr) { > - /* > - * nfsd_splice_actor may have already messed with the > - * page length; reset it so as not to confuse > - * xdr_truncate_encode: > - */ > - buf->page_len =3D 0; > - return nfserr; > - } > + if (host_err < 0) > + goto err; > + trace_nfsd_read_io_done(read->rd_rqstp, read->rd_fhp, > + read->rd_offset, maxcount); > + maxcount =3D host_err; > + nfsdstats.io_read +=3D maxcount; > + fsnotify_access(file); >=20 > eof =3D nfsd_eof_on_read(len, maxcount, read->rd_offset, > = d_inode(read->rd_fhp->fh_dentry)->i_size); > @@ -3470,6 +3472,17 @@ static __be32 nfsd4_encode_splice_read( > xdr->end =3D (__be32 *)((void *)xdr->end + space_left); >=20 > return 0; > + > +err: > + /* > + * nfsd_splice_actor may have already messed with the > + * page length; reset it so as not to confuse > + * xdr_truncate_encode: > + */ > + buf->page_len =3D 0; > + trace_nfsd_read_err(read->rd_rqstp, read->rd_fhp, > + read->rd_offset, host_err); > + return nfserrno(host_err); > } >=20 > static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp, > @@ -3477,12 +3490,12 @@ static __be32 nfsd4_encode_readv(struct = nfsd4_compoundres *resp, > struct file *file, unsigned long = maxcount) > { > struct xdr_stream *xdr =3D &resp->xdr; > + int host_err; > u32 eof; > int v; > int starting_len =3D xdr->buf->len - 8; > long len; > int thislen; > - __be32 nfserr; > __be32 tmp; > __be32 *p; > u32 zzz =3D 0; > @@ -3510,11 +3523,18 @@ static __be32 nfsd4_encode_readv(struct = nfsd4_compoundres *resp, > } > read->rd_vlen =3D v; >=20 > + trace_nfsd_read_vector(resp->rqstp, read->rd_fhp, > + read->rd_offset, maxcount); > len =3D maxcount; > - nfserr =3D nfsd_readv(file, read->rd_offset, = resp->rqstp->rq_vec, > - read->rd_vlen, &maxcount); > - if (nfserr) > - return nfserr; > + host_err =3D nfsd_readv(file, read->rd_offset, = resp->rqstp->rq_vec, > + read->rd_vlen, &maxcount); > + if (host_err < 0) > + goto err; > + trace_nfsd_read_io_done(resp->rqstp, read->rd_fhp, > + read->rd_offset, maxcount); I missed a spot. + maxcount =3D host_err; > + nfsdstats.io_read +=3D maxcount; > + fsnotify_access(file); > + > xdr_truncate_encode(xdr, starting_len + 8 + ((maxcount+3)&~3)); >=20 > eof =3D nfsd_eof_on_read(len, maxcount, read->rd_offset, > @@ -3530,6 +3550,10 @@ static __be32 nfsd4_encode_readv(struct = nfsd4_compoundres *resp, > &zzz, = pad); > return 0; >=20 > +err: > + trace_nfsd_read_err(resp->rqstp, read->rd_fhp, > + read->rd_offset, host_err); > + return nfserrno(host_err); > } >=20 > static __be32 > diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h > index 653e9ee..a8bbd9d 100644 > --- a/fs/nfsd/trace.h > +++ b/fs/nfsd/trace.h > @@ -43,7 +43,8 @@ > TP_ARGS(rqstp, fhp, offset, len)) >=20 > DEFINE_NFSD_IO_EVENT(read_start); > -DEFINE_NFSD_IO_EVENT(read_opened); > +DEFINE_NFSD_IO_EVENT(read_splice); > +DEFINE_NFSD_IO_EVENT(read_vector); > DEFINE_NFSD_IO_EVENT(read_io_done); > DEFINE_NFSD_IO_EVENT(read_done); > DEFINE_NFSD_IO_EVENT(write_start); > @@ -82,6 +83,7 @@ > int len), \ > TP_ARGS(rqstp, fhp, offset, len)) >=20 > +DEFINE_NFSD_ERR_EVENT(read_err); > DEFINE_NFSD_ERR_EVENT(write_err); >=20 > #include "state.h" > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c > index ee59a0b..0fa54b5 100644 > --- a/fs/nfsd/vfs.c > +++ b/fs/nfsd/vfs.c > @@ -881,19 +881,7 @@ static int nfsd_direct_splice_actor(struct = pipe_inode_info *pipe, > return __splice_from_pipe(pipe, sd, nfsd_splice_actor); > } >=20 > -static __be32 > -nfsd_finish_read(struct file *file, unsigned long *count, int = host_err) > -{ > - if (host_err >=3D 0) { > - nfsdstats.io_read +=3D host_err; > - *count =3D host_err; > - fsnotify_access(file); > - return 0; > - } else=20 > - return nfserrno(host_err); > -} > - > -__be32 nfsd_splice_read(struct svc_rqst *rqstp, > +int nfsd_splice_read(struct svc_rqst *rqstp, > struct file *file, loff_t offset, unsigned long = *count) > { > struct splice_desc sd =3D { > @@ -902,23 +890,18 @@ __be32 nfsd_splice_read(struct svc_rqst *rqstp, > .pos =3D offset, > .u.data =3D rqstp, > }; > - int host_err; >=20 > rqstp->rq_next_page =3D rqstp->rq_respages + 1; > - host_err =3D splice_direct_to_actor(file, &sd, = nfsd_direct_splice_actor); > - return nfsd_finish_read(file, count, host_err); > + return splice_direct_to_actor(file, &sd, = nfsd_direct_splice_actor); > } >=20 > -__be32 nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, = int vlen, > - unsigned long *count) > +int nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, = int vlen, > + unsigned long *count) > { > struct iov_iter iter; > - int host_err; >=20 > iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count); > - host_err =3D vfs_iter_read(file, &iter, &offset, 0); > - > - return nfsd_finish_read(file, count, host_err); > + return vfs_iter_read(file, &iter, &offset, 0); > } >=20 > /* > @@ -1025,6 +1008,7 @@ __be32 nfsd_read(struct svc_rqst *rqstp, struct = svc_fh *fhp, > { > struct file *file; > struct raparms *ra; > + int host_err; > __be32 err; >=20 > trace_nfsd_read_start(rqstp, fhp, offset, *count); > @@ -1034,14 +1018,24 @@ __be32 nfsd_read(struct svc_rqst *rqstp, = struct svc_fh *fhp, >=20 > ra =3D nfsd_init_raparms(file); >=20 > - trace_nfsd_read_opened(rqstp, fhp, offset, *count); > - > - if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, = &rqstp->rq_flags)) > - err =3D nfsd_splice_read(rqstp, file, offset, count); > - else > - err =3D nfsd_readv(file, offset, vec, vlen, count); > - > - trace_nfsd_read_io_done(rqstp, fhp, offset, *count); > + if (file->f_op->splice_read && > + test_bit(RQ_SPLICE_OK, &rqstp->rq_flags)) { > + trace_nfsd_read_splice(rqstp, fhp, offset, *count); > + host_err =3D nfsd_splice_read(rqstp, file, offset, = count); > + } else { > + trace_nfsd_read_vector(rqstp, fhp, offset, *count); > + host_err =3D nfsd_readv(file, offset, vec, vlen, count); > + } > + if (host_err >=3D 0) { > + trace_nfsd_read_io_done(rqstp, fhp, offset, host_err); > + nfsdstats.io_read +=3D host_err; > + *count =3D host_err; > + fsnotify_access(file); > + err =3D nfs_ok; > + } else { > + trace_nfsd_read_err(rqstp, fhp, offset, host_err); > + err =3D nfserrno(host_err); > + } >=20 > if (ra) > nfsd_put_raparams(file, ra); > diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h > index be6d8e0..d9131c3 100644 > --- a/fs/nfsd/vfs.h > +++ b/fs/nfsd/vfs.h > @@ -78,10 +78,10 @@ __be32 nfsd_commit(struct svc_rqst *, = struct svc_fh *, > __be32 nfsd_open(struct svc_rqst *, struct svc_fh *, = umode_t, > int, struct file **); > struct raparms; > -__be32 nfsd_splice_read(struct svc_rqst *, > - struct file *, loff_t, unsigned long *); > -__be32 nfsd_readv(struct file *, loff_t, struct kvec *, = int, > - unsigned long *); > +int nfsd_splice_read(struct svc_rqst *rqstp, struct file = *file, > + loff_t offset, unsigned long *count); > +int nfsd_readv(struct file *file, loff_t offset, struct kvec = *vec, > + int vlen, unsigned long *count); > __be32 nfsd_read(struct svc_rqst *, struct svc_fh *, > loff_t, struct kvec *, int, unsigned = long *); > __be32 nfsd_write(struct svc_rqst *, struct svc_fh *, = loff_t, >=20 > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" = in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Chuck Lever