crypto-check-blocksize-eq-pagesize

   1 ext4 crypto: fail the mount if blocksize != pagesize
   2
   3 We currently don't correctly handle the case where blocksize !=
   4 pagesize, so disallow the mount in those cases.
   5
   6 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   7 ---
   8  fs/ext4/super.c | 10 +++++++++-
   9  1 file changed, 9 insertions(+), 1 deletion(-)
  10
  11 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  12 index 31e85be..e13fe40 100644
  13 --- a/fs/ext4/super.c
  14 +++ b/fs/ext4/super.c
  15 @@ -4065,7 +4065,15 @@ no_journal:
  16                 }
  17         }
  18
  19 -       if (unlikely(sbi->s_mount_flags & EXT4_MF_TEST_DUMMY_ENCRYPTION) &&
  20 +       if ((DUMMY_ENCRYPTION_ENABLED(sbi) ||
  21 +            EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT)) &&
  22 +           (blocksize != PAGE_CACHE_SIZE)) {
  23 +               ext4_msg(sb, KERN_ERR,
  24 +                        "Unsupported blocksize for fs encryption");
  25 +               goto failed_mount_wq;
  26 +       }
  27 +
  28 +       if (DUMMY_ENCRYPTION_ENABLED(sbi) &&
  29             !(sb->s_flags & MS_RDONLY) &&
  30             !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT)) {
  31                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_ENCRYPT);