[PATCH v2] NFSD: trace export root filehandle event

[Chen Hanxiao <chenhx.fnst@xxxxxxxxxxx>]

Add a tracepoint for obtaining root filehandle event

Signed-off-by: Chen Hanxiao <chenhx.fnst@xxxxxxxxxxx>
---
v2:
	remove dentry address record
	add netns inum entry
	trace ex_flags

 fs/nfsd/export.c |  4 +---
 fs/nfsd/trace.h  | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 7b641095a665..63acd1564eab 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1027,15 +1027,13 @@ exp_rootfh(struct net *net, struct auth_domain *clp, char *name,
 	}
 	inode = d_inode(path.dentry);
 
-	dprintk("nfsd: exp_rootfh(%s [%p] %s:%s/%ld)\n",
-		 name, path.dentry, clp->name,
-		 inode->i_sb->s_id, inode->i_ino);
 	exp = exp_parent(cd, clp, &path);
 	if (IS_ERR(exp)) {
 		err = PTR_ERR(exp);
 		goto out;
 	}
 
+	trace_nfsd_exp_rootfh(net, name, clp->name, inode, exp);
 	/*
 	 * fh must be initialized before calling fh_compose
 	 */
diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 1cd2076210b1..adac651e398d 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -396,6 +396,47 @@ TRACE_EVENT(nfsd_export_update,
 	)
 );
 
+TRACE_EVENT(nfsd_exp_rootfh,
+	TP_PROTO(
+		const struct net *net,
+		const char *name,
+		const char *clp_name,
+		const struct inode *inode,
+		const struct svc_export *exp
+		),
+	TP_ARGS(net, name, clp_name, inode, exp),
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(unsigned int, netns_ino)
+		__string(clp_name, clp_name)
+		__string(s_id, inode->i_sb->s_id)
+		__field(unsigned long, i_ino)
+		__array(unsigned char, uuid, EX_UUID_LEN)
+		__field(int, ex_flags)
+		__field(const void *, ex_uuid)
+	),
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->netns_ino = net->ns.inum;
+		__assign_str(clp_name, clp_name);
+		__assign_str(s_id, inode->i_sb->s_id);
+		__entry->i_ino = inode->i_ino;
+		__entry->ex_flags = exp->ex_flags;
+		__entry->ex_uuid = exp->ex_uuid;
+		if (exp->ex_uuid)
+			memcpy(__entry->uuid, exp->ex_uuid, EX_UUID_LEN);
+	),
+	TP_printk(
+		"path=%s domain=%s sid=%s/inode=%ld ex_flags=%d ex_uuid=%s",
+		__get_str(name),
+		__get_str(clp_name),
+		__get_str(s_id),
+		__entry->i_ino,
+		__entry->ex_flags,
+		__entry->ex_uuid ? __print_hex_str(__entry->uuid, EX_UUID_LEN) : "NULL"
+	)
+);
+
 DECLARE_EVENT_CLASS(nfsd_io_class,
 	TP_PROTO(struct svc_rqst *rqstp,
 		 struct svc_fh	*fhp,
-- 
2.39.1