md: improve partition detection in md array

md currently uses ->media_changed to make sure rescan_partitions
is call on md array after they are assembled.

However that doesn't happen until the array is opened, which is later
than some people would like.

So use blkdev_ioctl to do the rescan immediately that the
array has been assembled.

This means we can remove all the ->change infrastructure as it was only used
to trigger a partition rescan.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 18 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 65814b0340cb..2901d0c0ee9e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3104,6 +3104,7 @@ static int do_md_run(mddev_t * mddev)
         struct gendisk *disk;
         struct mdk_personality *pers;
         char b[BDEVNAME_SIZE];
+        struct block_device *bdev;
 
         if (list_empty(&mddev->disks))
                 /* cannot run an array with no devices.. */
@@ -3331,7 +3332,13 @@ static int do_md_run(mddev_t * mddev)
         md_wakeup_thread(mddev->thread);
         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
 
-        mddev->changed = 1;
+        bdev = bdget_disk(mddev->gendisk, 0);
+        if (bdev) {
+                bd_set_size(bdev, mddev->array_size << 1);
+                blkdev_ioctl(bdev->bd_inode, NULL, BLKRRPART, 0);
+                bdput(bdev);
+        }
+
         md_new_event(mddev);
         kobject_uevent(&mddev->gendisk->kobj, KOBJ_CHANGE);
         return 0;
@@ -3453,7 +3460,6 @@ static int do_md_stop(mddev_t * mddev, int mode)
                         mddev->pers = NULL;
 
                         set_capacity(disk, 0);
-                        mddev->changed = 1;
 
                         if (mddev->ro)
                                 mddev->ro = 0;
@@ -4593,20 +4599,6 @@ static int md_release(struct inode *inode, struct file * file)
         return 0;
 }
 
-static int md_media_changed(struct gendisk *disk)
-{
-        mddev_t *mddev = disk->private_data;
-
-        return mddev->changed;
-}
-
-static int md_revalidate(struct gendisk *disk)
-{
-        mddev_t *mddev = disk->private_data;
-
-        mddev->changed = 0;
-        return 0;
-}
 static struct block_device_operations md_fops =
 {
         .owner          = THIS_MODULE,
@@ -4614,8 +4606,6 @@ static struct block_device_operations md_fops =
         .release        = md_release,
         .ioctl          = md_ioctl,
         .getgeo         = md_getgeo,
-        .media_changed  = md_media_changed,
-        .revalidate_disk= md_revalidate,
 };
 
 static int md_thread(void * arg)