md: remove recovery_disabled

'recovery_disabled' logic is complex and confusing, originally intended to
preserve raid in extreme scenarios. It was used in following cases:
- When sync fails and setting badblocks also fails, kick out non-In_sync
  rdev and block spare rdev from joining to preserve raid [1]
- When last backup is unavailable, prevent repeated add-remove of spares
  triggering recovery [2]

The original issues are now resolved:
- Error handlers in all raid types prevent last rdev from being kicked out
- Disks with failed recovery are marked Faulty and can't re-join

Therefore, remove 'recovery_disabled' as it's no longer needed.

[1] 5389042ffa36 ("md: change managed of recovery_disabled.")
[2] 4044ba58dd15 ("md: don't retry recovery of raid1 that fails due to error on source drive.")

Link: https://lore.kernel.org/linux-raid/20260105110300.1442509-13-linan666@huaweicloud.com
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Yu Kuai <yukuai@fnnas.com>

1 files changed, 3 insertions, 14 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a841c5784e24..79faec11b79e 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1760,7 +1760,6 @@ static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
 		set_bit(MD_BROKEN, &mddev->flags);
 
 		if (!test_bit(MD_FAILLAST_DEV, &mddev->flags)) {
-			conf->recovery_disabled = mddev->recovery_disabled;
 			spin_unlock_irqrestore(&conf->device_lock, flags);
 			return;
 		}
@@ -1904,7 +1903,6 @@ static bool raid1_remove_conf(struct r1conf *conf, int disk)
 
 	/* Only remove non-faulty devices if recovery is not possible. */
 	if (!test_bit(Faulty, &rdev->flags) &&
-	    rdev->mddev->recovery_disabled != conf->recovery_disabled &&
 	    rdev->mddev->degraded < conf->raid_disks)
 		return false;
 
@@ -1924,9 +1922,6 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 	int first = 0;
 	int last = conf->raid_disks - 1;
 
-	if (mddev->recovery_disabled == conf->recovery_disabled)
-		return -EBUSY;
-
 	if (rdev->raid_disk >= 0)
 		first = last = rdev->raid_disk;
 
@@ -2346,7 +2341,6 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
 		 */
 		if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) ||
 		    !fix_sync_read_error(r1_bio)) {
-			conf->recovery_disabled = mddev->recovery_disabled;
 			md_done_sync(mddev, r1_bio->sectors);
 			md_sync_error(mddev);
 			put_buf(r1_bio);
@@ -2948,16 +2942,12 @@ static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
 		*skipped = 1;
 		put_buf(r1_bio);
 
-		if (!ok) {
-			/* Cannot record the badblocks, so need to
+		if (!ok)
+			/* Cannot record the badblocks, md_error has set INTR,
 			 * abort the resync.
-			 * If there are multiple read targets, could just
-			 * fail the really bad ones ???
 			 */
-			conf->recovery_disabled = mddev->recovery_disabled;
-			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
 			return 0;
-		} else
+		else
 			return min_bad;
 
 	}
@@ -3144,7 +3134,6 @@ static struct r1conf *setup_conf(struct mddev *mddev)
 	init_waitqueue_head(&conf->wait_barrier);
 
 	bio_list_init(&conf->pending_bio_list);
-	conf->recovery_disabled = mddev->recovery_disabled - 1;
 
 	err = -EIO;
 	for (i = 0; i < conf->raid_disks * 2; i++) {