md: move suspend_hi/lo handling into core md code
responding to ->suspend_lo and ->suspend_hi is similar
to responding to ->suspended. It is best to wait in
the common core code without incrementing ->active_io.
This allows mddev_suspend()/mddev_resume() to work while
requests are waiting for suspend_lo/hi to change.
This is will be important after a subsequent patch
which uses mddev_suspend() to synchronize updating for
suspend_lo/hi.
So move the code for testing suspend_lo/hi out of raid1.c
and raid5.c, and place it in md.c
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 2cb49f6..68de2a6 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -266,16 +266,31 @@ static DEFINE_SPINLOCK(all_mddevs_lock);
* call has finished, the bio has been linked into some internal structure
* and so is visible to ->quiesce(), so we don't need the refcount any more.
*/
+static bool is_suspended(struct mddev *mddev, struct bio *bio)
+{
+ if (mddev->suspended)
+ return true;
+ if (bio_data_dir(bio) != WRITE)
+ return false;
+ if (mddev->suspend_lo >= mddev->suspend_hi)
+ return false;
+ if (bio->bi_iter.bi_sector >= mddev->suspend_hi)
+ return false;
+ if (bio_end_sector(bio) < mddev->suspend_lo)
+ return false;
+ return true;
+}
+
void md_handle_request(struct mddev *mddev, struct bio *bio)
{
check_suspended:
rcu_read_lock();
- if (mddev->suspended) {
+ if (is_suspended(mddev, bio)) {
DEFINE_WAIT(__wait);
for (;;) {
prepare_to_wait(&mddev->sb_wait, &__wait,
TASK_UNINTERRUPTIBLE);
- if (!mddev->suspended)
+ if (!is_suspended(mddev, bio))
break;
rcu_read_unlock();
schedule();
@@ -4845,10 +4860,11 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
goto unlock;
old = mddev->suspend_lo;
mddev->suspend_lo = new;
- if (new >= old)
+ if (new >= old) {
/* Shrinking suspended region */
+ wake_up(&mddev->sb_wait);
mddev->pers->quiesce(mddev, 2);
- else {
+ } else {
/* Expanding suspended region - need to wait */
mddev->pers->quiesce(mddev, 1);
mddev->pers->quiesce(mddev, 0);
@@ -4888,10 +4904,11 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
goto unlock;
old = mddev->suspend_hi;
mddev->suspend_hi = new;
- if (new <= old)
+ if (new <= old) {
/* Shrinking suspended region */
+ wake_up(&mddev->sb_wait);
mddev->pers->quiesce(mddev, 2);
- else {
+ } else {
/* Expanding suspended region - need to wait */
mddev->pers->quiesce(mddev, 1);
mddev->pers->quiesce(mddev, 0);