summaryrefslogtreecommitdiff
path: root/include/linux/ref_tracker.h
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2021-12-04 20:21:55 -0800
committerJakub Kicinski <kuba@kernel.org>2021-12-06 16:04:44 -0800
commit4e66934eaadc83b27ada8d42b60894018f3bfabf (patch)
treefc56c9432018c4128c6462cc5f970bd2212aab9d /include/linux/ref_tracker.h
parentce83278f313ce65a9bbd780a3e07fa3f62d82525 (diff)
lib: add reference counting tracking infrastructure
It can be hard to track where references are taken and released. In networking, we have annoying issues at device or netns dismantles, and we had various proposals to ease root causing them. This patch adds new infrastructure pairing refcount increases and decreases. This will self document code, because programmers will have to associate increments/decrements. This is controled by CONFIG_REF_TRACKER which can be selected by users of this feature. This adds both cpu and memory costs, and thus should probably be used with care. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/ref_tracker.h')
-rw-r--r--include/linux/ref_tracker.h73
1 files changed, 73 insertions, 0 deletions
diff --git a/include/linux/ref_tracker.h b/include/linux/ref_tracker.h
new file mode 100644
index 000000000000..c11c9db5825c
--- /dev/null
+++ b/include/linux/ref_tracker.h
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef _LINUX_REF_TRACKER_H
+#define _LINUX_REF_TRACKER_H
+#include <linux/refcount.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+
+struct ref_tracker;
+
+struct ref_tracker_dir {
+#ifdef CONFIG_REF_TRACKER
+ spinlock_t lock;
+ unsigned int quarantine_avail;
+ refcount_t untracked;
+ struct list_head list; /* List of active trackers */
+ struct list_head quarantine; /* List of dead trackers */
+#endif
+};
+
+#ifdef CONFIG_REF_TRACKER
+static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
+ unsigned int quarantine_count)
+{
+ INIT_LIST_HEAD(&dir->list);
+ INIT_LIST_HEAD(&dir->quarantine);
+ spin_lock_init(&dir->lock);
+ dir->quarantine_avail = quarantine_count;
+ refcount_set(&dir->untracked, 1);
+}
+
+void ref_tracker_dir_exit(struct ref_tracker_dir *dir);
+
+void ref_tracker_dir_print(struct ref_tracker_dir *dir,
+ unsigned int display_limit);
+
+int ref_tracker_alloc(struct ref_tracker_dir *dir,
+ struct ref_tracker **trackerp, gfp_t gfp);
+
+int ref_tracker_free(struct ref_tracker_dir *dir,
+ struct ref_tracker **trackerp);
+
+#else /* CONFIG_REF_TRACKER */
+
+static inline void ref_tracker_dir_init(struct ref_tracker_dir *dir,
+ unsigned int quarantine_count)
+{
+}
+
+static inline void ref_tracker_dir_exit(struct ref_tracker_dir *dir)
+{
+}
+
+static inline void ref_tracker_dir_print(struct ref_tracker_dir *dir,
+ unsigned int display_limit)
+{
+}
+
+static inline int ref_tracker_alloc(struct ref_tracker_dir *dir,
+ struct ref_tracker **trackerp,
+ gfp_t gfp)
+{
+ return 0;
+}
+
+static inline int ref_tracker_free(struct ref_tracker_dir *dir,
+ struct ref_tracker **trackerp)
+{
+ return 0;
+}
+
+#endif
+
+#endif /* _LINUX_REF_TRACKER_H */