[LTP] [PATCH] inotify11: Fix race condition between fork() and inotify init

[Amir Goldstein]

On Thu, Sep 8, 2022 at 5:50 PM Martin Doucha <mdoucha@suse.cz> wrote:
>
> When the child process runs a few churn cycles before the parent completes
> inotify initialization, the parent will get stuck reading the inotify
> file descriptor until it eventually times out. Create inotify watch
> befory fork()ing to prevent this race condition.
>
> Signed-off-by: Martin Doucha <mdoucha@suse.cz>

LGTM

Reviewed-by: Amir Goldstein <amir73il@gmail.com>


> ---
>  testcases/kernel/syscalls/inotify/inotify11.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/testcases/kernel/syscalls/inotify/inotify11.c b/testcases/kernel/syscalls/inotify/inotify11.c
> index e426f9e1c..dd32ea7fd 100644
> --- a/testcases/kernel/syscalls/inotify/inotify11.c
> +++ b/testcases/kernel/syscalls/inotify/inotify11.c
> @@ -61,15 +61,16 @@ static void verify_inotify(void)
>         struct inotify_event *event;
>         int inotify_fd;
>
> +       inotify_fd = SAFE_MYINOTIFY_INIT();
> +       SAFE_MYINOTIFY_ADD_WATCH(inotify_fd, ".", IN_DELETE);
> +
>         pid = SAFE_FORK();
>         if (pid == 0) {
> +               SAFE_CLOSE(inotify_fd);
>                 churn();
>                 return;
>         }
>
> -       inotify_fd = SAFE_MYINOTIFY_INIT();
> -       SAFE_MYINOTIFY_ADD_WATCH(inotify_fd, ".", IN_DELETE);
> -
>         while (!opened && nevents < CHURN_FILES) {
>                 int i, fd, len;
>
> --
> 2.37.2
>
>
> --
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