[RFC][PATCH 1/8] epoll: remove epmutex from ep_free() & eventpoll_release_file()

[Hou Tao]

Remove the global epmutex from ep_free() and eventpoll_release_file().
In the later patches, we will add locks with a smaller granularity
to serve the same purposes of epmutex.

Signed-off-by: Hou Tao <hout...@huawei.com>
---
 fs/eventpoll.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 2fabd19..26ab0c5 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -835,7 +835,6 @@ static void ep_free(struct eventpoll *ep)
         * anymore. The only hit might come from eventpoll_release_file() but
         * holding "epmutex" is sufficient here.
         */
-       mutex_lock(&epmutex);
 
        /*
         * Walks through the whole tree by unregistering poll callbacks.
@@ -863,7 +862,6 @@ static void ep_free(struct eventpoll *ep)
        }
        mutex_unlock(&ep->mtx);
 
-       mutex_unlock(&epmutex);
        mutex_destroy(&ep->mtx);
        free_uid(ep->user);
        wakeup_source_unregister(ep->ws);
@@ -1013,14 +1011,12 @@ void eventpoll_release_file(struct file *file)
         *
         * Besides, ep_remove() acquires the lock, so we can't hold it here.
         */
-       mutex_lock(&epmutex);
        list_for_each_entry_safe(epi, next, &file->f_ep_links, fllink) {
                ep = epi->ep;
                mutex_lock_nested(&ep->mtx, 0);
                ep_remove(ep, epi);
                mutex_unlock(&ep->mtx);
        }
-       mutex_unlock(&epmutex);
 }
 
 static int ep_alloc(struct eventpoll **pep)
-- 
2.7.5