Commit d5b9216f authored by Trond Myklebust's avatar Trond Myklebust
Browse files

pnfs/flexfiles: Add tracepoints for detecting pnfs fallback to MDS 



Add tracepoints to allow debugging of the event chain leading to
a pnfs fallback to doing I/O through the MDS.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 58bbeab4

fs/nfs/flexfilelayout/flexfilelayout.c

+26 −0
Original line number Diff line number Diff line
@@ -934,6 +934,10 @@ ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio, 
	if (pgio->pg_error < 0)

		return;

out_mds:

	trace_pnfs_mds_fallback_pg_init_read(pgio->pg_inode,

			0, NFS4_MAX_UINT64, IOMODE_READ,

			NFS_I(pgio->pg_inode)->layout,

			pgio->pg_lseg);

	pnfs_put_lseg(pgio->pg_lseg);

	pgio->pg_lseg = NULL;

	nfs_pageio_reset_read_mds(pgio);
@@ -1000,6 +1004,10 @@ ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio, 
	return;



out_mds:

	trace_pnfs_mds_fallback_pg_init_write(pgio->pg_inode,

			0, NFS4_MAX_UINT64, IOMODE_RW,

			NFS_I(pgio->pg_inode)->layout,

			pgio->pg_lseg);

	pnfs_put_lseg(pgio->pg_lseg);

	pgio->pg_lseg = NULL;

	nfs_pageio_reset_write_mds(pgio);
@@ -1026,6 +1034,10 @@ ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio, 
	if (pgio->pg_lseg)

		return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);



	trace_pnfs_mds_fallback_pg_get_mirror_count(pgio->pg_inode,

			0, NFS4_MAX_UINT64, IOMODE_RW,

			NFS_I(pgio->pg_inode)->layout,

			pgio->pg_lseg);

	/* no lseg means that pnfs is not in use, so no mirroring here */

	nfs_pageio_reset_write_mds(pgio);

out:
@@ -1075,6 +1087,10 @@ static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs) 
			hdr->args.count,

			(unsigned long long)hdr->args.offset);



		trace_pnfs_mds_fallback_write_done(hdr->inode,

				hdr->args.offset, hdr->args.count,

				IOMODE_RW, NFS_I(hdr->inode)->layout,

				hdr->lseg);

		task->tk_status = pnfs_write_done_resend_to_mds(hdr);

	}

}
@@ -1094,6 +1110,10 @@ static void ff_layout_reset_read(struct nfs_pgio_header *hdr) 
			hdr->args.count,

			(unsigned long long)hdr->args.offset);



		trace_pnfs_mds_fallback_read_done(hdr->inode,

				hdr->args.offset, hdr->args.count,

				IOMODE_READ, NFS_I(hdr->inode)->layout,

				hdr->lseg);

		task->tk_status = pnfs_read_done_resend_to_mds(hdr);

	}

}
@@ -1827,6 +1847,9 @@ ff_layout_read_pagelist(struct nfs_pgio_header *hdr) 
out_failed:

	if (ff_layout_avoid_mds_available_ds(lseg))

		return PNFS_TRY_AGAIN;

	trace_pnfs_mds_fallback_read_pagelist(hdr->inode,

			hdr->args.offset, hdr->args.count,

			IOMODE_READ, NFS_I(hdr->inode)->layout, lseg);

	return PNFS_NOT_ATTEMPTED;

}
@@ -1892,6 +1915,9 @@ ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync) 
out_failed:

	if (ff_layout_avoid_mds_available_ds(lseg))

		return PNFS_TRY_AGAIN;

	trace_pnfs_mds_fallback_write_pagelist(hdr->inode,

			hdr->args.offset, hdr->args.count,

			IOMODE_RW, NFS_I(hdr->inode)->layout, lseg);

	return PNFS_NOT_ATTEMPTED;

}

fs/nfs/nfs4trace.c

+8 −0
Original line number Diff line number Diff line
@@ -16,4 +16,12 @@ 
EXPORT_TRACEPOINT_SYMBOL_GPL(nfs4_pnfs_read);

EXPORT_TRACEPOINT_SYMBOL_GPL(nfs4_pnfs_write);

EXPORT_TRACEPOINT_SYMBOL_GPL(nfs4_pnfs_commit_ds);



EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_pg_init_read);

EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_pg_init_write);

EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_pg_get_mirror_count);

EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_read_done);

EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_write_done);

EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_read_pagelist);

EXPORT_TRACEPOINT_SYMBOL_GPL(pnfs_mds_fallback_write_pagelist);

#endif

fs/nfs/nfs4trace.h

+75 −1
Original line number Diff line number Diff line
@@ -1771,6 +1771,7 @@ TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_BLOCKED); 
TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_INVALID_OPEN);

TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_RETRY);

TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);

TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_EXIT);



#define show_pnfs_update_layout_reason(reason)				\

	__print_symbolic(reason,					\
@@ -1786,7 +1787,8 @@ TRACE_DEFINE_ENUM(PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET); 
		{ PNFS_UPDATE_LAYOUT_BLOCKED, "layouts blocked" },	\

		{ PNFS_UPDATE_LAYOUT_INVALID_OPEN, "invalid open" },	\

		{ PNFS_UPDATE_LAYOUT_RETRY, "retrying" },	\

		{ PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET, "sent layoutget" })

		{ PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET, "sent layoutget" }, \

		{ PNFS_UPDATE_LAYOUT_EXIT, "exit" })



TRACE_EVENT(pnfs_update_layout,

		TP_PROTO(struct inode *inode,
@@ -1845,6 +1847,78 @@ TRACE_EVENT(pnfs_update_layout, 
		)

);



DECLARE_EVENT_CLASS(pnfs_layout_event,

		TP_PROTO(struct inode *inode,

			loff_t pos,

			u64 count,

			enum pnfs_iomode iomode,

			struct pnfs_layout_hdr *lo,

			struct pnfs_layout_segment *lseg

		),

		TP_ARGS(inode, pos, count, iomode, lo, lseg),

		TP_STRUCT__entry(

			__field(dev_t, dev)

			__field(u64, fileid)

			__field(u32, fhandle)

			__field(loff_t, pos)

			__field(u64, count)

			__field(enum pnfs_iomode, iomode)

			__field(int, layoutstateid_seq)

			__field(u32, layoutstateid_hash)

			__field(long, lseg)

		),

		TP_fast_assign(

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

			__entry->fileid = NFS_FILEID(inode);

			__entry->fhandle = nfs_fhandle_hash(NFS_FH(inode));

			__entry->pos = pos;

			__entry->count = count;

			__entry->iomode = iomode;

			if (lo != NULL) {

				__entry->layoutstateid_seq =

				be32_to_cpu(lo->plh_stateid.seqid);

				__entry->layoutstateid_hash =

				nfs_stateid_hash(&lo->plh_stateid);

			} else {

				__entry->layoutstateid_seq = 0;

				__entry->layoutstateid_hash = 0;

			}

			__entry->lseg = (long)lseg;

		),

		TP_printk(

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

			"iomode=%s pos=%llu count=%llu "

			"layoutstateid=%d:0x%08x lseg=0x%lx",

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

			(unsigned long long)__entry->fileid,

			__entry->fhandle,

			show_pnfs_iomode(__entry->iomode),

			(unsigned long long)__entry->pos,

			(unsigned long long)__entry->count,

			__entry->layoutstateid_seq, __entry->layoutstateid_hash,

			__entry->lseg

		)

);



#define DEFINE_PNFS_LAYOUT_EVENT(name) \

	DEFINE_EVENT(pnfs_layout_event, name, \

		TP_PROTO(struct inode *inode, \

			loff_t pos, \

			u64 count, \

			enum pnfs_iomode iomode, \

			struct pnfs_layout_hdr *lo, \

			struct pnfs_layout_segment *lseg \

		), \

		TP_ARGS(inode, pos, count, iomode, lo, lseg))



DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_pg_init_read);

DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_pg_init_write);

DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_pg_get_mirror_count);

DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_read_done);

DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_write_done);

DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_read_pagelist);

DEFINE_PNFS_LAYOUT_EVENT(pnfs_mds_fallback_write_pagelist);



#endif /* CONFIG_NFS_V4_1 */



#endif /* _TRACE_NFS4_H */

fs/nfs/pnfs.c

+2 −0
Original line number Diff line number Diff line
@@ -2037,6 +2037,8 @@ pnfs_update_layout(struct inode *ino, 
out_put_layout_hdr:

	if (first)

		pnfs_clear_first_layoutget(lo);

	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,

				 PNFS_UPDATE_LAYOUT_EXIT);

	pnfs_put_layout_hdr(lo);

out:

	dprintk("%s: inode %s/%llu pNFS layout segment %s for "

include/linux/nfs4.h

+1 −0
Original line number Diff line number Diff line
@@ -660,6 +660,7 @@ enum pnfs_update_layout_reason { 
	PNFS_UPDATE_LAYOUT_BLOCKED,

	PNFS_UPDATE_LAYOUT_INVALID_OPEN,

	PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET,

	PNFS_UPDATE_LAYOUT_EXIT,

};



#define NFS4_OP_MAP_NUM_LONGS					\