Merge tag 'v6.6-vfs.super.fixes.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull more superblock follow-on fixes from Christian Brauner:
 "This contains two more small follow-up fixes for the super work this
  cycle. I went through all filesystems once more and detected two minor
  issues that still needed fixing:

   - Some filesystems support mtd devices (e.g., mount -t jffs2 mtd2
     /mnt). The mtd infrastructure uses the sb->s_mtd pointer to find an
     existing superblock. When the mtd device is put and sb->s_mtd
     cleared the superblock can still be found fs_supers and so this
     risks a use-after-free.

     Add a small patch that aligns mtd with what we did for regular
     block devices and switch keying to rely on sb->s_dev.

     (This was tested with mtd devices and jffs2 as xfstests doesn't
     support mtd devices.)

   - Switch nfs back to rely on kill_anon_super() so the superblock is
     removed from the list of active supers before sb->s_fs_info is
     freed"

* tag 'v6.6-vfs.super.fixes.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  NFS: switch back to using kill_anon_super
  mtd: key superblock by device number
  fs: export sget_dev()