[PATCH v2] fsnotify: Add missing annotation for fsnotify_finish_user_wait() and for fsnotify_prepare_user_wait()

From: Jules Irenge
Date: Mon Apr 13 2020 - 17:43:10 EST


Sparse reports warnings at fsnotify_prepare_user_wait()
and at fsnotify_finish_user_wait()

warning: context imbalance in fsnotify_finish_user_wait()
- wrong count at exit
warning: context imbalance in fsnotify_prepare_user_wait()
- unexpected unlock

The root cause is the missing annotation at fsnotify_finish_user_wait()
and at fsnotify_prepare_user_wait()
fsnotify_prepare_user_wait() has an extra annotation __release()
that only tell Sparse and not GCC to shutdown the warning

Add the missing __acquires(&fsnotify_mark_srcu) annotation
Add the missing __releases(&fsnotify_mark_srcu) annotation
Add the __release(&fsnotify_mark_srcu) annotation.

Signed-off-by: Jules Irenge <jbi.octave@xxxxxxxxx>
---
changes since v2
-include annotations for fsnotify_prepare_user_wait()

fs/notify/mark.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 1d96216dffd1..8387937b9d01 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -325,13 +325,16 @@ static void fsnotify_put_mark_wake(struct fsnotify_mark *mark)
}

bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info)
+ __releases(&fsnotify_mark_srcu)
{
int type;

fsnotify_foreach_obj_type(type) {
/* This can fail if mark is being removed */
- if (!fsnotify_get_mark_safe(iter_info->marks[type]))
+ if (!fsnotify_get_mark_safe(iter_info->marks[type])) {
+ __release(&fsnotify_mark_srcu);
goto fail;
+ }
}

/*
@@ -350,6 +353,7 @@ bool fsnotify_prepare_user_wait(struct fsnotify_iter_info *iter_info)
}

void fsnotify_finish_user_wait(struct fsnotify_iter_info *iter_info)
+ __acquires(&fsnotify_mark_srcu)
{
int type;

--
2.24.1