1 files changed, 18 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3db3d1b271f..fcb878f8879 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -307,6 +307,10 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
                 bio_io_error(bio);
                 return;
         }
+        if (mddev->ro == 1 && unlikely(rw == WRITE)) {
+                bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
+                return;
+        }
         smp_rmb(); /* Ensure implications of  'active' are visible */
         rcu_read_lock();
         if (mddev->suspended) {
@@ -2994,6 +2998,9 @@ rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
                 } else if (!sectors)
                         sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
                                 rdev->data_offset;
+                if (!my_mddev->pers->resize)
+                        /* Cannot change size for RAID0 or Linear etc */
+                        return -EINVAL;
         }
         if (sectors < my_mddev->dev_sectors)
                 return -EINVAL; /* component must fit device */
@@ -6525,7 +6532,17 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                         mddev->ro = 0;
                         sysfs_notify_dirent_safe(mddev->sysfs_state);
                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-                        md_wakeup_thread(mddev->thread);
+                        /* mddev_unlock will wake thread */
+                        /* If a device failed while we were read-only, we
+                         * need to make sure the metadata is updated now.
+                         */
+                        if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
+                                mddev_unlock(mddev);
+                                wait_event(mddev->sb_wait,
+                                           !test_bit(MD_CHANGE_DEVS, &mddev->flags) &&
+                                           !test_bit(MD_CHANGE_PENDING, &mddev->flags));
+                                mddev_lock(mddev);
+                        }
                 } else {
                         err = -EROFS;
                         goto abort_unlock;