@@ -244,6 +244,8 @@ static void ____fput(struct callback_head *work)
__fput(container_of(work, struct file, f_u.fu_rcuhead));
}
+static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput);
+
/*
* If kernel thread really needs to have the final fput() it has done
* to complete, call this. The only user right now is the boot - we
@@ -256,11 +258,9 @@ static void ____fput(struct callback_head *work)
*/
void flush_delayed_fput(void)
{
- delayed_fput(NULL);
+ flush_delayed_work(&delayed_fput_work);
}
-static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput);
-
void fput(struct file *file)
{
if (atomic_long_dec_and_test(&file->f_count)) {
I think there's a potential race in flush_delayed_fput. A kthread does an fput() and that file gets added to the list and the delayed work is scheduled. More than 1 jiffy passes, and the workqueue thread picks up the work and starts running it. Then the kthread calls flush_delayed_work. It sees that the list is empty and returns immediately, even though the __fput for its file may not have run yet. Close this by making flush_delayed_fput use flush_delayed_work instead, which should immediately schedule the work to run if it's not already, and block until the workqueue job completes. Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> --- fs/file_table.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)