fscache: Add tracepoints

[mirror_ubuntu-jammy-kernel.git] / fs / fscache / cookie.c

diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 98d22f495cd8f73a3b2ccf76a0f4801e7ffaa973..20bc3341f11311d83b468be21fa5baf46cc8c888 100644 (file)
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -101,7 +101,7 @@ struct fscache_cookie *__fscache_acquire_cookie(
         */
        atomic_set(&cookie->n_active, 1);
 
-       atomic_inc(&parent->usage);
+       fscache_cookie_get(parent, fscache_cookie_get_acquire_parent);
        atomic_inc(&parent->n_children);
 
        cookie->def             = def;
@@ -125,6 +125,8 @@ struct fscache_cookie *__fscache_acquire_cookie(
                break;
        }
 
+       trace_fscache_acquire(cookie);
+
        if (enable) {
                /* if the object is an index then we need do nothing more here
                 * - we create indices on disk when we need them as an index
@@ -134,7 +136,8 @@ struct fscache_cookie *__fscache_acquire_cookie(
                                set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
                        } else {
                                atomic_dec(&parent->n_children);
-                               __fscache_cookie_put(cookie);
+                               fscache_cookie_put(cookie,
+                                                  fscache_cookie_put_acquire_nobufs);
                                fscache_stat(&fscache_n_acquires_nobufs);
                                _leave(" = NULL");
                                return NULL;
@@ -159,6 +162,8 @@ void __fscache_enable_cookie(struct fscache_cookie *cookie,
 {
        _enter("%p", cookie);
 
+       trace_fscache_enable(cookie);
+
        wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
                         TASK_UNINTERRUPTIBLE);
 
@@ -318,7 +323,7 @@ static int fscache_alloc_object(struct fscache_cache *cache,
         * attached to the cookie */
        if (fscache_attach_object(cookie, object) < 0) {
                fscache_stat(&fscache_n_cop_put_object);
-               cache->ops->put_object(object);
+               cache->ops->put_object(object, fscache_obj_put_attach_fail);
                fscache_stat_d(&fscache_n_cop_put_object);
        }
 
@@ -338,7 +343,7 @@ object_already_extant:
 
 error_put:
        fscache_stat(&fscache_n_cop_put_object);
-       cache->ops->put_object(object);
+       cache->ops->put_object(object, fscache_obj_put_alloc_fail);
        fscache_stat_d(&fscache_n_cop_put_object);
 error:
        _leave(" = %d", ret);
@@ -398,7 +403,7 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
 
        /* attach to the cookie */
        object->cookie = cookie;
-       atomic_inc(&cookie->usage);
+       fscache_cookie_get(cookie, fscache_cookie_get_attach_object);
        hlist_add_head(&object->cookie_link, &cookie->backing_objects);
 
        fscache_objlist_add(object);
@@ -516,6 +521,8 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
 
        _enter("%p,%u", cookie, invalidate);
 
+       trace_fscache_disable(cookie);
+
        ASSERTCMP(atomic_read(&cookie->n_active), >, 0);
 
        if (atomic_read(&cookie->n_children) != 0) {
@@ -601,6 +608,8 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
               cookie, cookie->def->name, cookie->netfs_data,
               atomic_read(&cookie->n_active), retire);
 
+       trace_fscache_relinquish(cookie, retire);
+
        /* No further netfs-accessing operations on this cookie permitted */
        if (test_and_set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags))
                BUG();
@@ -620,35 +629,38 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
 
        /* Dispose of the netfs's link to the cookie */
        ASSERTCMP(atomic_read(&cookie->usage), >, 0);
-       fscache_cookie_put(cookie);
+       fscache_cookie_put(cookie, fscache_cookie_put_relinquish);
 
        _leave("");
 }
 EXPORT_SYMBOL(__fscache_relinquish_cookie);
 
 /*
- * destroy a cookie
+ * Drop a reference to a cookie.
  */
-void __fscache_cookie_put(struct fscache_cookie *cookie)
+void fscache_cookie_put(struct fscache_cookie *cookie,
+                       enum fscache_cookie_trace where)
 {
        struct fscache_cookie *parent;
+       int usage;
 
        _enter("%p", cookie);
 
-       for (;;) {
-               _debug("FREE COOKIE %p", cookie);
+       do {
+               usage = atomic_dec_return(&cookie->usage);
+               trace_fscache_cookie(cookie, where, usage);
+
+               if (usage > 0)
+                       return;
+               BUG_ON(usage < 0);
+
                parent = cookie->parent;
                BUG_ON(!hlist_empty(&cookie->backing_objects));
                kmem_cache_free(fscache_cookie_jar, cookie);
 
-               if (!parent)
-                       break;
-
                cookie = parent;
-               BUG_ON(atomic_read(&cookie->usage) <= 0);
-               if (!atomic_dec_and_test(&cookie->usage))
-                       break;
-       }
+               where = fscache_cookie_put_parent;
+       } while (cookie);
 
        _leave("");
 }