From a7ac203d8fd366bb6318f856466f52484c623d05 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Mon, 8 Nov 2021 16:08:07 +0100 Subject: [PATCH] gfs2: Fix "Introduce flag for glock holder auto-demotion" Function demote_incompat_holders iterates over the list of glock holders with list_for_each_entry, and it then sometimes removes the current holder from the list. This will get the loop stuck; we must use list_for_each_entry_safe instead. Reported-by: Dan Carpenter Signed-off-by: Andreas Gruenbacher --- fs/gfs2/glock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 258d8aa..8dbd6fe 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -411,14 +411,14 @@ static void do_error(struct gfs2_glock *gl, const int ret) static void demote_incompat_holders(struct gfs2_glock *gl, struct gfs2_holder *new_gh) { - struct gfs2_holder *gh; + struct gfs2_holder *gh, *tmp; /* * Demote incompatible holders before we make ourselves eligible. * (This holder may or may not allow auto-demoting, but we don't want * to demote the new holder before it's even granted.) */ - list_for_each_entry(gh, &gl->gl_holders, gh_list) { + list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { /* * Since holders are at the front of the list, we stop when we * find the first non-holder. -- 2.7.4