md: export 'frozen' resync state through sysfs
The md resync engine has a 'frozen' state which ensures that
no resync/recovery. This is used to avoid races.
Export this state through the 'sync_action' sysfs attribute
so that user-space can benefit and also avoid some races.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 58e0b02..384e4f0 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3306,7 +3306,9 @@
action_show(mddev_t *mddev, char *page)
{
char *type = "idle";
- if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+ if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
+ type = "frozen";
+ else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
(!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
type = "reshape";
@@ -3329,7 +3331,12 @@
if (!mddev->pers || !mddev->pers->sync_request)
return -EINVAL;
- if (cmd_match(page, "idle")) {
+ if (cmd_match(page, "frozen"))
+ set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ else
+ clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+
+ if (cmd_match(page, "idle") || cmd_match(page, "frozen")) {
if (mddev->sync_thread) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_unregister_thread(mddev->sync_thread);