[RFC PATCH 11/27] ep_loop_check_proc(): lift pushing the cookie into callers

Al Viro
2020-10-04T02:40:45Z

fs/eventpoll.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 33af838046ea..9edea3933790 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1877,9 +1877,6 @@ static int ep_loop_check_proc(void *priv, void *cookie, int depth)
struct rb_node *rbp;
struct epitem *epi;

- if (!ep_push_nested(cookie)) /* limits recursion */
- return -1;
-
mutex_lock_nested(&ep->mtx, depth + 1);
ep->gen = loop_check_gen;
for (rbp = rb_first_cached(&ep->rbr); rbp; rbp = rb_next(rbp)) {
@@ -1888,8 +1885,13 @@ static int ep_loop_check_proc(void *priv, void *cookie, int depth)
ep_tovisit = epi->ffd.file->private_data;
if (ep_tovisit->gen == loop_check_gen)
continue;
- error = ep_loop_check_proc(epi->ffd.file, ep_tovisit,
+ if (!ep_push_nested(ep_tovisit)) {
+ error = -1;
+ } else {
+ error = ep_loop_check_proc(epi->ffd.file, ep_tovisit,
depth + 1);
+ nesting--;
+ }
if (error != 0)
break;
} else {
@@ -1909,7 +1911,6 @@ static int ep_loop_check_proc(void *priv, void *cookie, int depth)
}
}
mutex_unlock(&ep->mtx);
- nesting--; /* pop */

return error;
}
@@ -1927,7 +1928,12 @@ static int ep_loop_check_proc(void *priv, void *cookie, int depth)
*/
static int ep_loop_check(struct eventpoll *ep, struct file *file)
{
- return ep_loop_check_proc(file, ep, 0);
+ int err;
+
+ ep_push_nested(ep); // can't fail
+ err = ep_loop_check_proc(file, ep, 0);
+ nesting--;
+ return err;
}

static void clear_tfile_check_list(void)
--
2.11.0