fscache: Add tracepoints
Add some tracepoints to fscache:
(*) fscache_cookie - Tracks a cookie's usage count.
(*) fscache_netfs - Logs registration of a network filesystem, including
the pointer to the cookie allocated.
(*) fscache_acquire - Logs cookie acquisition.
(*) fscache_relinquish - Logs cookie relinquishment.
(*) fscache_enable - Logs enablement of a cookie.
(*) fscache_disable - Logs disablement of a cookie.
(*) fscache_osm - Tracks execution of states in the object state machine.
and cachefiles:
(*) cachefiles_ref - Tracks a cachefiles object's usage count.
(*) cachefiles_lookup - Logs result of lookup_one_len().
(*) cachefiles_mkdir - Logs result of vfs_mkdir().
(*) cachefiles_create - Logs result of vfs_create().
(*) cachefiles_unlink - Logs calls to vfs_unlink().
(*) cachefiles_rename - Logs calls to vfs_rename().
(*) cachefiles_mark_active - Logs an object becoming active.
(*) cachefiles_wait_active - Logs a wait for an old object to be
destroyed.
(*) cachefiles_mark_inactive - Logs an object becoming inactive.
(*) cachefiles_mark_buried - Logs the burial of an object.
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 0ff4b49..c27e2db 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -29,6 +29,7 @@
#define pr_fmt(fmt) "FS-Cache: " fmt
#include <linux/fscache-cache.h>
+#include <trace/events/fscache.h>
#include <linux/sched.h>
#define FSCACHE_MIN_THREADS 4
@@ -49,7 +50,8 @@ extern struct fscache_cache *fscache_select_cache_for_object(
extern struct kmem_cache *fscache_cookie_jar;
extern void fscache_cookie_init_once(void *);
-extern void __fscache_cookie_put(struct fscache_cookie *);
+extern void fscache_cookie_put(struct fscache_cookie *,
+ enum fscache_cookie_trace);
/*
* fsdef.c
@@ -311,14 +313,12 @@ static inline void fscache_raise_event(struct fscache_object *object,
fscache_enqueue_object(object);
}
-/*
- * drop a reference to a cookie
- */
-static inline void fscache_cookie_put(struct fscache_cookie *cookie)
+static inline void fscache_cookie_get(struct fscache_cookie *cookie,
+ enum fscache_cookie_trace where)
{
- BUG_ON(atomic_read(&cookie->usage) <= 0);
- if (atomic_dec_and_test(&cookie->usage))
- __fscache_cookie_put(cookie);
+ int usage = atomic_inc_return(&cookie->usage);
+
+ trace_fscache_cookie(cookie, where, usage);
}
/*
