Commit 87c5942e authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields
Browse files

nfsd: Add I/O trace points in the NFSv4 read proc 



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: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent d890be15

fs/nfsd/nfs4proc.c

+5 −0
Original line number Diff line number Diff line
@@ -751,6 +751,9 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, 
	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 @@ nfsd4_read_release(union nfsd4_op_u *u) 
{

	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

fs/nfsd/nfs4xdr.c

+6 −4
Original line number Diff line number Diff line
@@ -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));

fs/nfsd/trace.h

+3 −1
Original line number Diff line number Diff line
@@ -43,7 +43,8 @@ DEFINE_EVENT(nfsd_io_class, nfsd_##name, \ 
	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 @@ DEFINE_EVENT(nfsd_err_class, nfsd_##name, \ 
		 int		len),		\

	TP_ARGS(rqstp, fhp, offset, len))



DEFINE_NFSD_ERR_EVENT(read_err);

DEFINE_NFSD_ERR_EVENT(write_err);



#include "state.h"

fs/nfsd/vfs.c

+18 −16
Original line number Diff line number Diff line
@@ -881,19 +881,23 @@ 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,

__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 = {
@@ -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);

fs/nfsd/vfs.h

+7 −4
Original line number Diff line number Diff line
@@ -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,

CRA Git | Maintained and supported by SUSTech CRA and CCSE