NFSD: Separate tracepoints for acquire and create

These tracepoints collect different information: the create case does
not open a file, so there's no nf_file available.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/filecache.c

@@ -1040,7 +1040,7 @@ nfsd_file_is_cached(struct inode *inode)
 }
 
 static __be32
-nfsd_do_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
+nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		     unsigned int may_flags, struct nfsd_file **pnf, bool open)
 {
 	struct nfsd_file_lookup_key key = {
@@ -1121,7 +1121,8 @@ nfsd_do_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 
 out_status:
 	put_cred(key.cred);
-	trace_nfsd_file_acquire(rqstp, key.inode, may_flags, nf, status);
+	if (open)
+		trace_nfsd_file_acquire(rqstp, key.inode, may_flags, nf, status);
 	return status;
 
 open_file:
@@ -1169,7 +1170,7 @@ __be32
 nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		  unsigned int may_flags, struct nfsd_file **pnf)
 {
-	return nfsd_do_file_acquire(rqstp, fhp, may_flags, pnf, true);
+	return nfsd_file_do_acquire(rqstp, fhp, may_flags, pnf, true);
 }
 
 /**
@@ -1186,7 +1187,7 @@ __be32
 nfsd_file_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 		 unsigned int may_flags, struct nfsd_file **pnf)
 {
-	return nfsd_do_file_acquire(rqstp, fhp, may_flags, pnf, false);
+	return nfsd_file_do_acquire(rqstp, fhp, may_flags, pnf, false);
 }
 
 /*

fs/nfsd/nfs4state.c

@@ -5104,6 +5104,7 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp,
 				goto out_put_access;
 			nf->nf_file = open->op_filp;
 			open->op_filp = NULL;
+			trace_nfsd_file_create(rqstp, access, nf);
 		}
 
 		spin_lock(&fp->fi_lock);

fs/nfsd/trace.h

@@ -782,10 +782,10 @@ DEFINE_NFSD_FILE_EVENT(nfsd_file_unhash_and_dispose);
 
 TRACE_EVENT(nfsd_file_acquire,
 	TP_PROTO(
-		struct svc_rqst *rqstp,
-		struct inode *inode,
+		const struct svc_rqst *rqstp,
+		const struct inode *inode,
 		unsigned int may_flags,
-		struct nfsd_file *nf,
+		const struct nfsd_file *nf,
 		__be32 status
 	),
 
@@ -793,12 +793,12 @@ TRACE_EVENT(nfsd_file_acquire,
 
 	TP_STRUCT__entry(
 		__field(u32, xid)
-		__field(void *, inode)
+		__field(const void *, inode)
 		__field(unsigned long, may_flags)
-		__field(int, nf_ref)
+		__field(unsigned int, nf_ref)
 		__field(unsigned long, nf_flags)
 		__field(unsigned long, nf_may)
-		__field(struct file *, nf_file)
+		__field(const void *, nf_file)
 		__field(u32, status)
 	),
 
@@ -813,12 +813,50 @@ TRACE_EVENT(nfsd_file_acquire,
 		__entry->status = be32_to_cpu(status);
 	),
 
-	TP_printk("xid=0x%x inode=%p may_flags=%s ref=%d nf_flags=%s nf_may=%s nf_file=%p status=%u",
+	TP_printk("xid=0x%x inode=%p may_flags=%s ref=%u nf_flags=%s nf_may=%s nf_file=%p status=%u",
 			__entry->xid, __entry->inode,
 			show_nfsd_may_flags(__entry->may_flags),
 			__entry->nf_ref, show_nf_flags(__entry->nf_flags),
 			show_nfsd_may_flags(__entry->nf_may),
-			__entry->nf_file, __entry->status)
+			__entry->nf_file, __entry->status
+	)
+);
+
+TRACE_EVENT(nfsd_file_create,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		unsigned int may_flags,
+		const struct nfsd_file *nf
+	),
+
+	TP_ARGS(rqstp, may_flags, nf),
+
+	TP_STRUCT__entry(
+		__field(const void *, nf_inode)
+		__field(const void *, nf_file)
+		__field(unsigned long, may_flags)
+		__field(unsigned long, nf_flags)
+		__field(unsigned long, nf_may)
+		__field(unsigned int, nf_ref)
+		__field(u32, xid)
+	),
+
+	TP_fast_assign(
+		__entry->nf_inode = nf->nf_inode;
+		__entry->nf_file = nf->nf_file;
+		__entry->may_flags = may_flags;
+		__entry->nf_flags = nf->nf_flags;
+		__entry->nf_may = nf->nf_may;
+		__entry->nf_ref = refcount_read(&nf->nf_ref);
+		__entry->xid = be32_to_cpu(rqstp->rq_xid);
+	),
+
+	TP_printk("xid=0x%x inode=%p may_flags=%s ref=%u nf_flags=%s nf_may=%s nf_file=%p",
+		__entry->xid, __entry->nf_inode,
+		show_nfsd_may_flags(__entry->may_flags),
+		__entry->nf_ref, show_nf_flags(__entry->nf_flags),
+		show_nfsd_may_flags(__entry->nf_may), __entry->nf_file
+	)
 );
 
 TRACE_EVENT(nfsd_file_insert_err,