dm: return early from dm_pr_call() if DM device is suspended

stable inclusion
from stable-v5.10.137
commit b7e2d64d673abdecae8b8f3f44ef37820e7e8f6c
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b7e2d64d673abdecae8b8f3f44ef37820e7e8f6c

--------------------------------

[ Upstream commit e120a5f1 ]

Otherwise PR ops may be issued while the broader DM device is being
reconfigured, etc.

Fixes: 9c72bad1 ("dm: call PR reserve/unreserve on each underlying device")
Signed-off-by: NMike Snitzer <snitzer@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

drivers/md/dm.c

@@ -2985,6 +2985,11 @@ static int dm_call_pr(struct block_device *bdev, iterate_devices_callout_fn fn,
 		goto out;
 	ti = dm_table_get_target(table, 0);
 
+	if (dm_suspended_md(md)) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
 	ret = -EINVAL;
 	if (!ti->type->iterate_devices)
 		goto out;