fscache: add tracepoint when failing cookie

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>

fs/fscache/cookie.c

@@ -263,6 +263,8 @@ void fscache_caching_failed(struct fscache_cookie *cookie)
 {
 	clear_bit(FSCACHE_COOKIE_IS_CACHING, &cookie->flags);
 	fscache_set_cookie_state(cookie, FSCACHE_COOKIE_STATE_FAILED);
+	trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
+				fscache_cookie_failed);
 }
 EXPORT_SYMBOL(fscache_caching_failed);
 

include/trace/events/fscache.h

@@ -49,6 +49,7 @@ enum fscache_volume_trace {
 enum fscache_cookie_trace {
 	fscache_cookie_collision,
 	fscache_cookie_discard,
+	fscache_cookie_failed,
 	fscache_cookie_get_attach_object,
 	fscache_cookie_get_end_access,
 	fscache_cookie_get_hash_collision,
@@ -131,6 +132,7 @@ enum fscache_access_trace {
 #define fscache_cookie_traces						\
 	EM(fscache_cookie_collision,		"*COLLIDE*")		\
 	EM(fscache_cookie_discard,		"DISCARD  ")		\
+	EM(fscache_cookie_failed,		"FAILED   ")		\
 	EM(fscache_cookie_get_attach_object,	"GET attch")		\
 	EM(fscache_cookie_get_hash_collision,	"GET hcoll")		\
 	EM(fscache_cookie_get_end_access,	"GQ  endac")		\