md: Fix rdev_size_store with size == 0

Fix rdev_size_store with size == 0.
size == 0 means to use the largest size allowed by the
underlying device and is used when modifying an active array.

This fixes a regression introduced by
 commit d7027458d68b2f1752a28016dcf2ffd0a7e8f567

Cc: <stable@kernel.org>
Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 2 insertions, 4 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0a3a4bdcd4af..7d8c2bb0a67c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2106,8 +2106,6 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 
         if (strict_strtoull(buf, 10, &size) < 0)
                 return -EINVAL;
-        if (size < my_mddev->size)
-                return -EINVAL;
         if (my_mddev->pers && rdev->raid_disk >= 0) {
                 if (my_mddev->persistent) {
                         size = super_types[my_mddev->major_version].
@@ -2118,9 +2116,9 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                         size = (rdev->bdev->bd_inode->i_size >> 10);
                         size -= rdev->data_offset/2;
                 }
-                if (size < my_mddev->size)
-                        return -EINVAL; /* component must fit device */
         }
+        if (size < my_mddev->size)
+                return -EINVAL; /* component must fit device */
 
         rdev->size = size;
         if (size > oldsize && my_mddev->external) {