[PATCH RFC 19/24] nfs: new tracepoint in nfs_delegation_need_return

[Jeff Layton <jlayton@kernel.org>]

Add a tracepoint in the function that decides whether to return a
delegation to the server.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfs/delegation.c |  2 ++
 fs/nfs/nfs4trace.h  | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index a331a2dbae12..88dbec4739d3 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -571,6 +571,8 @@ static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
 {
 	bool ret = false;
 
+	trace_nfs_delegation_need_return(delegation);
+
 	if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
 		ret = true;
 	else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) {
diff --git a/fs/nfs/nfs4trace.h b/fs/nfs/nfs4trace.h
index b4ebac1961cc..e5adfb755dc7 100644
--- a/fs/nfs/nfs4trace.h
+++ b/fs/nfs/nfs4trace.h
@@ -14,6 +14,8 @@
 #include <trace/misc/fs.h>
 #include <trace/misc/nfs.h>
 
+#include "delegation.h"
+
 #define show_nfs_fattr_flags(valid) \
 	__print_flags((unsigned long)valid, "|", \
 		{ NFS_ATTR_FATTR_TYPE, "TYPE" }, \
@@ -928,6 +930,51 @@ DEFINE_NFS4_SET_DELEGATION_EVENT(nfs4_set_delegation);
 DEFINE_NFS4_SET_DELEGATION_EVENT(nfs4_reclaim_delegation);
 DEFINE_NFS4_SET_DELEGATION_EVENT(nfs4_detach_delegation);
 
+#define show_delegation_flags(flags) \
+	__print_flags(flags, "|", \
+		{ BIT(NFS_DELEGATION_NEED_RECLAIM), "NEED_RECLAIM" }, \
+		{ BIT(NFS_DELEGATION_RETURN), "RETURN" }, \
+		{ BIT(NFS_DELEGATION_RETURN_IF_CLOSED), "RETURN_IF_CLOSED" }, \
+		{ BIT(NFS_DELEGATION_REFERENCED), "REFERENCED" }, \
+		{ BIT(NFS_DELEGATION_RETURNING), "RETURNING" }, \
+		{ BIT(NFS_DELEGATION_REVOKED), "REVOKED" }, \
+		{ BIT(NFS_DELEGATION_TEST_EXPIRED), "TEST_EXPIRED" }, \
+		{ BIT(NFS_DELEGATION_INODE_FREEING), "INODE_FREEING" }, \
+		{ BIT(NFS_DELEGATION_RETURN_DELAYED), "RETURN_DELAYED" })
+
+DECLARE_EVENT_CLASS(nfs4_delegation_event,
+		TP_PROTO(
+			const struct nfs_delegation *delegation
+		),
+
+		TP_ARGS(delegation),
+
+		TP_STRUCT__entry(
+			__field(u32, fhandle)
+			__field(unsigned int, fmode)
+			__field(unsigned long, flags)
+		),
+
+		TP_fast_assign(
+			__entry->fhandle = nfs_fhandle_hash(NFS_FH(delegation->inode));
+			__entry->fmode = delegation->type;
+			__entry->flags = delegation->flags;
+		),
+
+		TP_printk(
+			"fhandle=0x%08x fmode=%s flags=%s",
+			__entry->fhandle, show_fs_fmode_flags(__entry->fmode),
+			show_delegation_flags(__entry->flags)
+		)
+);
+#define DEFINE_NFS4_DELEGATION_EVENT(name) \
+	DEFINE_EVENT(nfs4_delegation_event, name, \
+			TP_PROTO( \
+				const struct nfs_delegation *delegation \
+			), \
+			TP_ARGS(delegation))
+DEFINE_NFS4_DELEGATION_EVENT(nfs_delegation_need_return);
+
 TRACE_EVENT(nfs4_delegreturn_exit,
 		TP_PROTO(
 			const struct nfs4_delegreturnargs *args,

-- 
2.44.0