[RFC PATCH 06/27] untangling ep_call_nested(): move push/pop of cookie into the callbacks

[Al Viro]

From: Al Viro <v...@zeniv.linux.org.uk>

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
 fs/eventpoll.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index bd2cc78c47c8..9a6ee5991f3d 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -455,15 +455,7 @@ static bool ep_push_nested(void *cookie)
 static int ep_call_nested(int (*nproc)(void *, void *, int), void *priv,
                          void *cookie)
 {
-       int error;
-
-       if (!ep_push_nested(cookie))
-               return -1;
-       /* Call the nested function */
-       error = (*nproc)(priv, cookie, nesting - 1);
-       nesting--;
-
-       return error;
+       return (*nproc)(priv, cookie, nesting);
 }
 
 /*
@@ -1340,6 +1332,9 @@ static int reverse_path_check_proc(void *priv, void 
*cookie, int call_nests)
        struct file *child_file;
        struct epitem *epi;
 
+       if (!ep_push_nested(cookie)) /* limits recursion */
+               return -1;
+
        /* CTL_DEL can remove links here, but that can't increase our count */
        rcu_read_lock();
        list_for_each_entry_rcu(epi, &file->f_ep_links, fllink) {
@@ -1362,6 +1357,7 @@ static int reverse_path_check_proc(void *priv, void 
*cookie, int call_nests)
                }
        }
        rcu_read_unlock();
+       nesting--; /* pop */
        return error;
 }
 
@@ -1913,6 +1909,9 @@ static int ep_loop_check_proc(void *priv, void *cookie, 
int call_nests)
        struct rb_node *rbp;
        struct epitem *epi;
 
+       if (!ep_push_nested(cookie)) /* limits recursion */
+               return -1;
+
        mutex_lock_nested(&ep->mtx, call_nests + 1);
        ep->gen = loop_check_gen;
        for (rbp = rb_first_cached(&ep->rbr); rbp; rbp = rb_next(rbp)) {
@@ -1942,6 +1941,7 @@ static int ep_loop_check_proc(void *priv, void *cookie, 
int call_nests)
                }
        }
        mutex_unlock(&ep->mtx);
+       nesting--; /* pop */
 
        return error;
 }
-- 
2.11.0