Commit cda94457 authored by Mike Snitzer's avatar Mike Snitzer Committed by Anna Schumaker
Browse files

nfs/localio: add tracepoints for misaligned DIO READ and WRITE support 



Add nfs_local_dio_class and use it to create nfs_local_dio_read,
nfs_local_dio_write and nfs_local_dio_misaligned trace events.

These trace events show how NFS LOCALIO splits a given misaligned
IO into a mix of misaligned head and/or tail extents and a DIO-aligned
middle extent.  The misaligned head and/or tail extents are issued
using buffered IO and the DIO-aligned middle is issued using O_DIRECT.

This combination of trace events is useful for LOCALIO DIO READs:

  echo 1 > /sys/kernel/tracing/events/nfs/nfs_local_dio_read/enable
  echo 1 > /sys/kernel/tracing/events/nfs/nfs_local_dio_misaligned/enable
  echo 1 > /sys/kernel/tracing/events/nfs/nfs_initiate_read/enable
  echo 1 > /sys/kernel/tracing/events/nfs/nfs_readpage_done/enable
  echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_read/enable

This combination of trace events is useful for LOCALIO DIO WRITEs:

  echo 1 > /sys/kernel/tracing/events/nfs/nfs_local_dio_write/enable
  echo 1 > /sys/kernel/tracing/events/nfs/nfs_local_dio_misaligned/enable
  echo 1 > /sys/kernel/tracing/events/nfs/nfs_initiate_write/enable
  echo 1 > /sys/kernel/tracing/events/nfs/nfs_writeback_done/enable
  echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_write/enable

Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
Signed-off-by: default avatarAnna Schumaker <anna.schumaker@oracle.com>
parent c817248f

fs/nfs/internal.h

+10 −0
Original line number Diff line number Diff line
@@ -456,6 +456,16 @@ extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode); 


#if IS_ENABLED(CONFIG_NFS_LOCALIO)

/* localio.c */

struct nfs_local_dio {

	u32 mem_align;

	u32 offset_align;

	loff_t middle_offset;

	loff_t end_offset;

	ssize_t	start_len;	/* Length for misaligned first extent */

	ssize_t	middle_len;	/* Length for DIO-aligned middle extent */

	ssize_t	end_len;	/* Length for misaligned last extent */

};



extern void nfs_local_probe_async(struct nfs_client *);

extern void nfs_local_probe_async_work(struct work_struct *);

extern struct nfsd_file *nfs_local_open_fh(struct nfs_client *,

fs/nfs/localio.c

+8 −11
Original line number Diff line number Diff line
@@ -322,16 +322,6 @@ nfs_local_iocb_alloc(struct nfs_pgio_header *hdr, 
	return iocb;

}



struct nfs_local_dio {

	u32 mem_align;

	u32 offset_align;

	loff_t middle_offset;

	loff_t end_offset;

	ssize_t	start_len;	/* Length for misaligned first extent */

	ssize_t	middle_len;	/* Length for DIO-aligned middle extent */

	ssize_t	end_len;	/* Length for misaligned last extent */

};



static bool

nfs_is_local_dio_possible(struct nfs_local_kiocb *iocb, int rw,

			  size_t len, struct nfs_local_dio *local_dio)
@@ -367,6 +357,10 @@ nfs_is_local_dio_possible(struct nfs_local_kiocb *iocb, int rw, 
	local_dio->middle_len = middle_end - start_end;

	local_dio->end_len = orig_end - middle_end;



	if (rw == ITER_DEST)

		trace_nfs_local_dio_read(hdr->inode, offset, len, local_dio);

	else

		trace_nfs_local_dio_write(hdr->inode, offset, len, local_dio);

	return true;

}
@@ -446,8 +440,11 @@ nfs_local_iters_setup_dio(struct nfs_local_kiocb *iocb, int rw, 
		nfs_iov_iter_aligned_bvec(&iters[n_iters],

			local_dio->mem_align-1, local_dio->offset_align-1);



	if (unlikely(!iocb->iter_is_dio_aligned[n_iters]))

	if (unlikely(!iocb->iter_is_dio_aligned[n_iters])) {

		trace_nfs_local_dio_misaligned(iocb->hdr->inode,

			iocb->hdr->args.offset, len, local_dio);

		return 0; /* no DIO-aligned IO possible */

	}

	++n_iters;



	iocb->n_iters = n_iters;

fs/nfs/nfs2xdr.c

+1 −1
Original line number Diff line number Diff line
@@ -23,8 +23,8 @@ 
#include <linux/nfs2.h>

#include <linux/nfs_fs.h>

#include <linux/nfs_common.h>

#include "nfstrace.h"

#include "internal.h"

#include "nfstrace.h"



#define NFSDBG_FACILITY		NFSDBG_XDR

fs/nfs/nfs3xdr.c

+1 −1
Original line number Diff line number Diff line
@@ -23,8 +23,8 @@ 
#include <linux/nfsacl.h>

#include <linux/nfs_common.h>



#include "nfstrace.h"

#include "internal.h"

#include "nfstrace.h"



#define NFSDBG_FACILITY		NFSDBG_XDR

fs/nfs/nfstrace.h

+70 −0
Original line number Diff line number Diff line
@@ -1732,6 +1732,76 @@ DEFINE_NFS_DIRECT_REQ_EVENT(nfs_direct_write_completion); 
DEFINE_NFS_DIRECT_REQ_EVENT(nfs_direct_write_schedule_iovec);

DEFINE_NFS_DIRECT_REQ_EVENT(nfs_direct_write_reschedule_io);



#if IS_ENABLED(CONFIG_NFS_LOCALIO)



DECLARE_EVENT_CLASS(nfs_local_dio_class,

	TP_PROTO(

		const struct inode *inode,

		loff_t offset,

		ssize_t count,

		const struct nfs_local_dio *local_dio

	),

	TP_ARGS(inode, offset, count, local_dio),

	TP_STRUCT__entry(

		__field(dev_t, dev)

		__field(u64, fileid)

		__field(u32, fhandle)

		__field(loff_t, offset)

		__field(ssize_t, count)

		__field(u32, mem_align)

		__field(u32, offset_align)

		__field(loff_t, start)

		__field(ssize_t, start_len)

		__field(loff_t, middle)

		__field(ssize_t, middle_len)

		__field(loff_t, end)

		__field(ssize_t, end_len)

	),

	TP_fast_assign(

		const struct nfs_inode *nfsi = NFS_I(inode);

		const struct nfs_fh *fh = &nfsi->fh;



		__entry->dev = inode->i_sb->s_dev;

		__entry->fileid = nfsi->fileid;

		__entry->fhandle = nfs_fhandle_hash(fh);

		__entry->offset = offset;

		__entry->count = count;

		__entry->mem_align = local_dio->mem_align;

		__entry->offset_align = local_dio->offset_align;

		__entry->start = offset;

		__entry->start_len = local_dio->start_len;

		__entry->middle = local_dio->middle_offset;

		__entry->middle_len = local_dio->middle_len;

		__entry->end = local_dio->end_offset;

		__entry->end_len = local_dio->end_len;

	),

	TP_printk("fileid=%02x:%02x:%llu fhandle=0x%08x "

		  "offset=%lld count=%zd "

		  "mem_align=%u offset_align=%u "

		  "start=%llu+%zd middle=%llu+%zd end=%llu+%zd",

		  MAJOR(__entry->dev), MINOR(__entry->dev),

		  (unsigned long long)__entry->fileid,

		  __entry->fhandle, __entry->offset, __entry->count,

		  __entry->mem_align, __entry->offset_align,

		  __entry->start, __entry->start_len,

		  __entry->middle, __entry->middle_len,

		  __entry->end, __entry->end_len)

)



#define DEFINE_NFS_LOCAL_DIO_EVENT(name)		\

DEFINE_EVENT(nfs_local_dio_class, nfs_local_dio_##name,	\

	TP_PROTO(const struct inode *inode,		\

		 loff_t offset,				\

		 ssize_t count,				\

		 const struct nfs_local_dio *local_dio),\

	TP_ARGS(inode, offset, count, local_dio))



DEFINE_NFS_LOCAL_DIO_EVENT(read);

DEFINE_NFS_LOCAL_DIO_EVENT(write);

DEFINE_NFS_LOCAL_DIO_EVENT(misaligned);



#endif /* CONFIG_NFS_LOCALIO */



TRACE_EVENT(nfs_fh_to_dentry,

		TP_PROTO(

			const struct super_block *sb,