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>

4 files changed, 9 insertions, 33 deletions

diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 54c8677f1e59..5fe39c2a3d2b 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -257,6 +257,7 @@ static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev)
         rcu_assign_pointer(mddev->private, newconf);
         md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
         set_capacity(mddev->gendisk, mddev->array_sectors);
+        revalidate_disk(mddev->gendisk);
         call_rcu(&oldconf->rcu, free_conf);
         return 0;
 }
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;
 }
 
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 67e794d0097f..8726fd7ebce5 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2134,6 +2134,7 @@ static int raid1_resize(mddev_t *mddev, sector_t sectors)
                 return -EINVAL;
         set_capacity(mddev->gendisk, mddev->array_sectors);
         mddev->changed = 1;
+        revalidate_disk(mddev->gendisk);
         if (sectors > mddev->dev_sectors &&
             mddev->recovery_cp == MaxSector) {
                 mddev->recovery_cp = mddev->dev_sectors;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2dc35b4c20ac..2b521ee67dfa 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4858,6 +4858,7 @@ static int raid5_resize(mddev_t *mddev, sector_t sectors)
                 return -EINVAL;
         set_capacity(mddev->gendisk, mddev->array_sectors);
         mddev->changed = 1;
+        revalidate_disk(mddev->gendisk);
         if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
                 mddev->recovery_cp = mddev->dev_sectors;
                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -5058,7 +5059,6 @@ static void end_reshape(raid5_conf_t *conf)
  */
 static void raid5_finish_reshape(mddev_t *mddev)
 {
-        struct block_device *bdev;
         raid5_conf_t *conf = mddev->private;
 
         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
@@ -5067,15 +5067,7 @@ static void raid5_finish_reshape(mddev_t *mddev)
                         md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
                         set_capacity(mddev->gendisk, mddev->array_sectors);
                         mddev->changed = 1;
-
-                        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);
-                        }
+                        revalidate_disk(mddev->gendisk);
                 } else {
                         int d;
                         mddev->degraded = conf->raid_disks;