[PATCH v4 06/18] nfsd: add tracepoint to nfsd_symlink

[cel]

From: Jeff Layton <jlayton@xxxxxxxxxx>

Observe the start of SYMLINK operations for all NFS versions.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
 fs/nfsd/trace.h | 27 +++++++++++++++++++++++++++
 fs/nfsd/vfs.c   |  2 ++
 2 files changed, 29 insertions(+)

diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index a71d605fd7b7..e347cdaaa732 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -2444,6 +2444,33 @@ TRACE_EVENT(nfsd_vfs_create,
 	)
 );
 
+TRACE_EVENT(nfsd_vfs_symlink,
+	TP_PROTO(
+		const struct svc_rqst *rqstp,
+		const struct svc_fh *fhp,
+		const char *name,
+		unsigned int namelen,
+		const char *target
+	),
+	TP_ARGS(rqstp, fhp, name, namelen, target),
+	TP_STRUCT__entry(
+		NFSD_TRACE_PROC_CALL_FIELDS(rqstp)
+		__field(u32, fh_hash)
+		__string_len(name, name, namelen)
+		__string(target, target)
+	),
+	TP_fast_assign(
+		NFSD_TRACE_PROC_CALL_ASSIGNMENTS(rqstp);
+		__entry->fh_hash = knfsd_fh_hash(&fhp->fh_handle);
+		__assign_str(name);
+		__assign_str(target);
+	),
+	TP_printk("xid=0x%08x fh_hash=0x%08x name=%s target=%s",
+		__entry->xid, __entry->fh_hash,
+		__get_str(name), __get_str(target)
+	)
+);
+
 #endif /* _NFSD_TRACE_H */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index cc0efc47dc25..ecd453b260b6 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1651,6 +1651,8 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	__be32		err, cerr;
 	int		host_err;
 
+	trace_nfsd_vfs_symlink(rqstp, fhp, fname, flen, path);
+
 	err = nfserr_noent;
 	if (!flen || path[0] == '\0')
 		goto out;
-- 
2.49.0