md: Use revalidate_disk to effect changes in size of device.

As revalidate_disk calls check_disk_size_change, it will cause
any capacity change of a gendisk to be propagated to the blockdev
inode.  So use that instead of mucking about with locks and
i_size_write.

Also add a call to revalidate_disk in do_md_run and a few other places
where the gendisk capacity is changed.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 5 insertions, 23 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 52c988b072d0..5b98bea4ff9b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3741,17 +3741,8 @@ array_size_store(mddev_t *mddev, const char *buf, size_t len)
 
 	mddev->array_sectors = sectors;
 	set_capacity(mddev->gendisk, mddev->array_sectors);
-	if (mddev->pers) {
-		struct block_device *bdev = bdget_disk(mddev->gendisk, 0);
-
-		if (bdev) {
-			mutex_lock(&bdev->bd_inode->i_mutex);
-			i_size_write(bdev->bd_inode,
-				     (loff_t)mddev->array_sectors << 9);
-			mutex_unlock(&bdev->bd_inode->i_mutex);
-			bdput(bdev);
-		}
-	}
+	if (mddev->pers)
+		revalidate_disk(mddev->gendisk);
 
 	return len;
 }
@@ -4241,6 +4232,7 @@ static int do_md_run(mddev_t * mddev)
 	md_wakeup_thread(mddev->thread);
 	md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
 
+	revalidate_disk(mddev->gendisk);
 	mddev->changed = 1;
 	md_new_event(mddev);
 	sysfs_notify_dirent(mddev->sysfs_state);
@@ -5139,18 +5131,8 @@ static int update_size(mddev_t *mddev, sector_t num_sectors)
 			return -ENOSPC;
 	}
 	rv = mddev->pers->resize(mddev, num_sectors);
-	if (!rv) {
-		struct block_device *bdev;
-
-		bdev = bdget_disk(mddev->gendisk, 0);
-		if (bdev) {
-			mutex_lock(&bdev->bd_inode->i_mutex);
-			i_size_write(bdev->bd_inode,
-				     (loff_t)mddev->array_sectors << 9);
-			mutex_unlock(&bdev->bd_inode->i_mutex);
-			bdput(bdev);
-		}
-	}
+	if (!rv)
+		revalidate_disk(mddev->gendisk);
 	return rv;
 }