raid5-cache: suspend reclaim thread instead of shutdown
There is mechanism to suspend a kernel thread. Use it instead of playing
create/destroy game.
Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Cc: Song Liu <songliubraving@fb.com>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 62f3fb9..297757a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7187,10 +7187,12 @@
wait_event_interruptible_timeout
(thread->wqueue,
test_bit(THREAD_WAKEUP, &thread->flags)
- || kthread_should_stop(),
+ || kthread_should_stop() || kthread_should_park(),
thread->timeout);
clear_bit(THREAD_WAKEUP, &thread->flags);
+ if (kthread_should_park())
+ kthread_parkme();
if (!kthread_should_stop())
thread->run(thread);
}
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 8cb79fc..5f817bd 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -19,6 +19,7 @@
#include <linux/raid/md_p.h>
#include <linux/crc32c.h>
#include <linux/random.h>
+#include <linux/kthread.h>
#include "md.h"
#include "raid5.h"
#include "bitmap.h"
@@ -1437,23 +1438,14 @@
struct mddev *mddev;
if (!log || state == 2)
return;
- if (state == 0) {
- /*
- * This is a special case for hotadd. In suspend, the array has
- * no journal. In resume, journal is initialized as well as the
- * reclaim thread.
- */
- if (log->reclaim_thread)
- return;
- log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
- log->rdev->mddev, "reclaim");
- log->reclaim_thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
- } else if (state == 1) {
+ if (state == 0)
+ kthread_unpark(log->reclaim_thread->tsk);
+ else if (state == 1) {
/* make sure r5l_write_super_and_discard_space exits */
mddev = log->rdev->mddev;
wake_up(&mddev->sb_wait);
+ kthread_park(log->reclaim_thread->tsk);
r5l_wake_reclaim(log, MaxSector);
- md_unregister_thread(&log->reclaim_thread);
r5l_do_reclaim(log);
}
}