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 <chuck.lever@xxxxxxxxxx> 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 <chuck.lever@xxxxxxxxxx>
> > ---
> > 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 <linux/file.h>
> > #include <linux/slab.h>
> > #include <linux/namei.h>
> > +#include <linux/fsnotify.h>
> > #include <linux/statfs.h>
> > #include <linux/utsname.h>
> > #include <linux/pagemap.h>
> > @@ -50,6 +51,7 @@
> > #include "cache.h"
> > #include "netns.h"
> > #include "pnfs.h"
> > +#include "trace.h"
> >
> > #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
> > #include <linux/security.h>
> > @@ -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,
> >
> > --
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>
> --
> Chuck Lever
>
>
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