linux-kernel - [patch]block: stack unplug

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Tue, 10 Jul 2012 13:02:26 +0800
From:	Shaohua Li <shli@...nel.org>
To:	linux-kernel@...r.kernel.org
Cc:	axboe@...nel.dk, neilb@...e.de
Subject: [patch]block: stack unplug

MD raid1 prepares to dispatch request in unplug callback. If make_request in
low level queue also uses unplug callback to dispatch request, the low level
queue's unplug callback will not be called. Recheck the callback list helps
this case.

Signed-off-by: Shaohua Li <shli@...ionio.com>

diff --git a/block/blk-core.c b/block/blk-core.c
index 93eb3e4..700cbfa 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2900,17 +2900,16 @@ static void flush_plug_callbacks(struct blk_plug *plug)
 {
 	LIST_HEAD(callbacks);
 
-	if (list_empty(&plug->cb_list))
-		return;
-
-	list_splice_init(&plug->cb_list, &callbacks);
+	while (!list_empty(&plug->cb_list)) {
+		list_splice_init(&plug->cb_list, &callbacks);
 
-	while (!list_empty(&callbacks)) {
-		struct blk_plug_cb *cb = list_first_entry(&callbacks,
+		while (!list_empty(&callbacks)) {
+			struct blk_plug_cb *cb = list_first_entry(&callbacks,
 							  struct blk_plug_cb,
 							  list);
-		list_del(&cb->list);
-		cb->callback(cb);
+			list_del(&cb->list);
+			cb->callback(cb);
+		}
 	}
 }
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/