[PATCH] md: fix locking problem in r5/r6

bitmap_unplug actually writes data (bits) to storage, so we shouldn't be
holding a spinlock...

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index e2a4028..36d5f8a 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1704,7 +1704,9 @@ static void raid5d (mddev_t *mddev)
 
                if (conf->seq_flush - conf->seq_write > 0) {
                        int seq = conf->seq_flush;
+                       spin_unlock_irq(&conf->device_lock);
                        bitmap_unplug(mddev->bitmap);
+                       spin_lock_irq(&conf->device_lock);
                        conf->seq_write = seq;
                        activate_bit_delay(conf);
                }

diff --git a/drivers/md/raid6main.c b/drivers/md/raid6main.c
index eae5a35..17d88d9 100644 (file)
--- a/drivers/md/raid6main.c
+++ b/drivers/md/raid6main.c
@@ -1784,7 +1784,9 @@ static void raid6d (mddev_t *mddev)
 
                if (conf->seq_flush - conf->seq_write > 0) {
                        int seq = conf->seq_flush;
+                       spin_unlock_irq(&conf->device_lock);
                        bitmap_unplug(mddev->bitmap);
+                       spin_lock_irq(&conf->device_lock);
                        conf->seq_write = seq;
                        activate_bit_delay(conf);
                }