Return-Path: Received: from fieldses.org ([173.255.197.46]:57706 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751257AbeC0UOr (ORCPT ); Tue, 27 Mar 2018 16:14:47 -0400 Date: Tue, 27 Mar 2018 16:14:47 -0400 From: Bruce Fields To: Chuck Lever Cc: Linux NFS Mailing List Subject: Re: [PATCH v2 15/18] nfsd: Add I/O trace points in the NFSv4 read proc Message-ID: <20180327201447.GD22077@fieldses.org> References: <20180327144420.7710.82288.stgit@oracle-ib-101.nfsv4bat.org> <20180327145340.7710.93006.stgit@oracle-ib-101.nfsv4bat.org> <97BBDD8C-AE6F-480B-8C6A-A98B2CDF9E10@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <97BBDD8C-AE6F-480B-8C6A-A98B2CDF9E10@oracle.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Could you check that I got this right in git://linux-nfs.org/~bfields/linux.git nfsd-next --b. On Tue, Mar 27, 2018 at 12:57:17PM -0400, Chuck Lever wrote: > > > > On Mar 27, 2018, at 10:53 AM, Chuck Lever wrote: > > > > 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. > > > > 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. > > > > The svc_fh is not passed to the read helpers, so some code > > duplication is necessary. > > > > 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(-) > > > > 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 >= OFFSET_MAX) > > return nfserr_inval; > > > > + 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); > > } > > > > 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" > > > > #ifdef CONFIG_NFSD_V4_SECURITY_LABEL > > #include > > @@ -3416,28 +3418,28 @@ static __be32 nfsd4_encode_splice_read( > > { > > struct xdr_stream *xdr = &resp->xdr; > > struct xdr_buf *buf = xdr->buf; > > + int host_err; > > u32 eof; > > long len; > > int space_left; > > - __be32 nfserr; > > __be32 *p = xdr->p - 2; > > > > /* Make sure there will be room for padding if needed */ > > if (xdr->end - xdr->p < 1) > > return nfserr_resource; > > > > + trace_nfsd_read_splice(resp->rqstp, read->rd_fhp, > > + read->rd_offset, maxcount); > > len = maxcount; > > - nfserr = nfsd_splice_read(read->rd_rqstp, file, > > + host_err = 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 = 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 = host_err; > > + nfsdstats.io_read += maxcount; > > + fsnotify_access(file); > > > > eof = 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 = (__be32 *)((void *)xdr->end + space_left); > > > > 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 = 0; > > + trace_nfsd_read_err(read->rd_rqstp, read->rd_fhp, > > + read->rd_offset, host_err); > > + return nfserrno(host_err); > > } > > > > 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 = &resp->xdr; > > + int host_err; > > u32 eof; > > int v; > > int starting_len = xdr->buf->len - 8; > > long len; > > int thislen; > > - __be32 nfserr; > > __be32 tmp; > > __be32 *p; > > u32 zzz = 0; > > @@ -3510,11 +3523,18 @@ static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp, > > } > > read->rd_vlen = v; > > > > + trace_nfsd_read_vector(resp->rqstp, read->rd_fhp, > > + read->rd_offset, maxcount); > > len = maxcount; > > - nfserr = nfsd_readv(file, read->rd_offset, resp->rqstp->rq_vec, > > - read->rd_vlen, &maxcount); > > - if (nfserr) > > - return nfserr; > > + host_err = 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 = host_err; > > > + nfsdstats.io_read += maxcount; > > + fsnotify_access(file); > > + > > xdr_truncate_encode(xdr, starting_len + 8 + ((maxcount+3)&~3)); > > > > eof = 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; > > > > +err: > > + trace_nfsd_read_err(resp->rqstp, read->rd_fhp, > > + read->rd_offset, host_err); > > + return nfserrno(host_err); > > } > > > > 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)) > > > > 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)) > > > > +DEFINE_NFSD_ERR_EVENT(read_err); > > DEFINE_NFSD_ERR_EVENT(write_err); > > > > #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); > > } > > > > -static __be32 > > -nfsd_finish_read(struct file *file, unsigned long *count, int host_err) > > -{ > > - if (host_err >= 0) { > > - nfsdstats.io_read += host_err; > > - *count = host_err; > > - fsnotify_access(file); > > - return 0; > > - } else > > - 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 = { > > @@ -902,23 +890,18 @@ __be32 nfsd_splice_read(struct svc_rqst *rqstp, > > .pos = offset, > > .u.data = rqstp, > > }; > > - int host_err; > > > > rqstp->rq_next_page = rqstp->rq_respages + 1; > > - host_err = 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); > > } > > > > -__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; > > > > iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count); > > - host_err = vfs_iter_read(file, &iter, &offset, 0); > > - > > - return nfsd_finish_read(file, count, host_err); > > + return vfs_iter_read(file, &iter, &offset, 0); > > } > > > > /* > > @@ -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; > > > > trace_nfsd_read_start(rqstp, fhp, offset, *count); > > @@ -1034,14 +1018,24 @@ __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, > > > > ra = nfsd_init_raparms(file); > > > > - trace_nfsd_read_opened(rqstp, fhp, offset, *count); > > - > > - if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags)) > > - err = nfsd_splice_read(rqstp, file, offset, count); > > - else > > - err = 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 = nfsd_splice_read(rqstp, file, offset, count); > > + } else { > > + trace_nfsd_read_vector(rqstp, fhp, offset, *count); > > + host_err = nfsd_readv(file, offset, vec, vlen, count); > > + } > > + if (host_err >= 0) { > > + trace_nfsd_read_io_done(rqstp, fhp, offset, host_err); > > + nfsdstats.io_read += host_err; > > + *count = host_err; > > + fsnotify_access(file); > > + err = nfs_ok; > > + } else { > > + trace_nfsd_read_err(rqstp, fhp, offset, host_err); > > + err = nfserrno(host_err); > > + } > > > > 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, > > > > -- > > 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 > >