From: Oleg Drokin Date: Wed, 7 Dec 2016 03:53:48 +0000 (-0500) Subject: staging/lustre/osc: Revert erroneous list_for_each_entry_safe use X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=38b2dc0b0f380984cd4fcc208497f8366f85f856;p=linux-beck.git staging/lustre/osc: Revert erroneous list_for_each_entry_safe use commit cd15dd6ef4ea11df87f717b8b1b83aaa738ec8af upstream. I have been having a lot of unexplainable crashes in osc_lru_shrink lately that I could not see a good explanation for and then I found this patch that slip under the radar somehow that incorrectly converted while loop for lru list iteration into list_for_each_entry_safe totally ignoring that in the body of the loop we drop spinlocks guarding this list and move list entries around. Not sure why it was not showing up right away, perhaps some of the more recent LRU changes committed caused some extra pressure on this code that finally highlighted the breakage. Reverts: 8adddc36b1fc ("staging: lustre: osc: Use list_for_each_entry_safe") CC: Bhaktipriya Shridhar Signed-off-by: Oleg Drokin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c index 2a7a70aa9e80..9168451d2f29 100644 --- a/drivers/staging/lustre/lustre/osc/osc_page.c +++ b/drivers/staging/lustre/lustre/osc/osc_page.c @@ -542,7 +542,6 @@ long osc_lru_shrink(const struct lu_env *env, struct client_obd *cli, struct cl_object *clobj = NULL; struct cl_page **pvec; struct osc_page *opg; - struct osc_page *temp; int maxscan = 0; long count = 0; int index = 0; @@ -569,13 +568,15 @@ long osc_lru_shrink(const struct lu_env *env, struct client_obd *cli, spin_lock(&cli->cl_lru_list_lock); maxscan = min(target << 1, atomic_long_read(&cli->cl_lru_in_list)); - list_for_each_entry_safe(opg, temp, &cli->cl_lru_list, ops_lru) { + while (!list_empty(&cli->cl_lru_list)) { struct cl_page *page; bool will_free = false; if (--maxscan < 0) break; + opg = list_entry(cli->cl_lru_list.next, struct osc_page, + ops_lru); page = opg->ops_cl.cpl_page; if (lru_page_busy(cli, page)) { list_move_tail(&opg->ops_lru, &cli->cl_lru_list);