[PATCH] md: Don't remove bitmap from md array when switching to read-only

While a read-only array doesn't not really need a bitmap, we should
not remove the bitmap when switching an array to read-only because
 a/ There is no code to re-add the bitmap which switching to read-write,
 b/ There is insufficient locking - the bitmap could be accessed while it is
    being removed.

Cc: Reuben Farrelly <reuben-lkml@reub.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 06dee51456e8..653d4dcbee23 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2689,14 +2689,6 @@ static int do_md_stop(mddev_t * mddev, int ro)
                         set_disk_ro(disk, 1);
         }
 
-        bitmap_destroy(mddev);
-        if (mddev->bitmap_file) {
-                atomic_set(&mddev->bitmap_file->f_dentry->d_inode->i_writecount, 1);
-                fput(mddev->bitmap_file);
-                mddev->bitmap_file = NULL;
-        }
-        mddev->bitmap_offset = 0;
-
         /*
          * Free resources if final stop
          */
@@ -2706,6 +2698,14 @@ static int do_md_stop(mddev_t * mddev, int ro)
                 struct gendisk *disk;
                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
+                bitmap_destroy(mddev);
+                if (mddev->bitmap_file) {
+                        atomic_set(&mddev->bitmap_file->f_dentry->d_inode->i_writecount, 1);
+                        fput(mddev->bitmap_file);
+                        mddev->bitmap_file = NULL;
+                }
+                mddev->bitmap_offset = 0;
+
                 ITERATE_RDEV(mddev,rdev,tmp)
                         if (rdev->raid_disk >= 0) {
                                 char nm[20];