On Wed, Mar 28, 2018 at 01:29:11PM -0400, 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 invoked for NFSv4 reads.
>
> Move the NFSD READ trace points to common helpers so that NFSv4
> reads are captured.
>
> Also, record any local I/O error that occurs, the total count of
> bytes that were actually returned, and whether splice or vectored
> read was used.
>
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> Hi Bruce-
>
> This version replaces v2 "nfsd: Add I/O trace points in the NFSv4
> read proc".
Applying, thanks!
--b.
>
> Changes since v2:
> - Ensure NFSv4 and legacy NFS READ encoders behave the same
>
>
> fs/nfsd/nfs4proc.c | 5 +++++
> fs/nfsd/nfs4xdr.c | 10 ++++++----
> fs/nfsd/trace.h | 4 +++-
> fs/nfsd/vfs.c | 34 ++++++++++++++++++----------------
> fs/nfsd/vfs.h | 11 +++++++----
> 5 files changed, 39 insertions(+), 25 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..f99d426 100644
> --- a/fs/nfsd/nfs4xdr.c
> +++ b/fs/nfsd/nfs4xdr.c
> @@ -3427,8 +3427,9 @@ static __be32 nfsd4_encode_splice_read(
> return nfserr_resource;
>
> len = maxcount;
> - nfserr = nfsd_splice_read(read->rd_rqstp, file,
> - read->rd_offset, &maxcount);
> + nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
> + file, read->rd_offset, &maxcount);
> + read->rd_length = maxcount;
> if (nfserr) {
> /*
> * nfsd_splice_actor may have already messed with the
> @@ -3511,8 +3512,9 @@ static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
> read->rd_vlen = v;
>
> len = maxcount;
> - nfserr = nfsd_readv(file, read->rd_offset, resp->rqstp->rq_vec,
> - read->rd_vlen, &maxcount);
> + nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
> + resp->rqstp->rq_vec, read->rd_vlen, &maxcount);
> + read->rd_length = maxcount;
> if (nfserr)
> return nfserr;
> xdr_truncate_encode(xdr, starting_len + 8 + ((maxcount+3)&~3));
> 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..2410b09 100644
> --- a/fs/nfsd/vfs.c
> +++ b/fs/nfsd/vfs.c
> @@ -881,20 +881,24 @@ 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)
> +static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
> + struct file *file, loff_t offset,
> + unsigned long *count, int host_err)
> {
> if (host_err >= 0) {
> nfsdstats.io_read += host_err;
> *count = host_err;
> fsnotify_access(file);
> + trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
> return 0;
> - } else
> + } else {
> + trace_nfsd_read_err(rqstp, fhp, offset, host_err);
> return nfserrno(host_err);
> + }
> }
>
> -__be32 nfsd_splice_read(struct svc_rqst *rqstp,
> - struct file *file, loff_t offset, unsigned long *count)
> +__be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
> + struct file *file, loff_t offset, unsigned long *count)
> {
> struct splice_desc sd = {
> .len = 0,
> @@ -904,21 +908,23 @@ __be32 nfsd_splice_read(struct svc_rqst *rqstp,
> };
> int host_err;
>
> + trace_nfsd_read_splice(rqstp, fhp, offset, *count);
> 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 nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
> }
>
> -__be32 nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen,
> - unsigned long *count)
> +__be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
> + struct file *file, loff_t offset,
> + struct kvec *vec, int vlen, unsigned long *count)
> {
> struct iov_iter iter;
> int host_err;
>
> + trace_nfsd_read_vector(rqstp, fhp, offset, *count);
> 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 nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
> }
>
> /*
> @@ -1034,14 +1040,10 @@ __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);
> + err = nfsd_splice_read(rqstp, fhp, file, offset, count);
> else
> - err = nfsd_readv(file, offset, vec, vlen, count);
> -
> - trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
> + err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count);
>
> if (ra)
> nfsd_put_raparams(file, ra);
> diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h
> index be6d8e0..a7e1073 100644
> --- a/fs/nfsd/vfs.h
> +++ b/fs/nfsd/vfs.h
> @@ -78,10 +78,13 @@ __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 *);
> +__be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
> + struct file *file, loff_t offset,
> + unsigned long *count);
> +__be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
> + 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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