ext4: calculate and verify inode checksums

This patch introduces to ext4 the ability to calculate and verify
inode checksums.  This requires the use of a new ro compatibility flag
and some accompanying e2fsprogs patches to provide the relevant
features in tune2fs and e2fsck.  The inode generation changes have
been integrated into this patch.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 6eee25591b81..feba55a225a6 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -152,6 +152,13 @@ flags_out:
                 if (!inode_owner_or_capable(inode))
                         return -EPERM;
 
+                if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+                                EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+                        ext4_warning(sb, "Setting inode version is not "
+                                     "supported with metadata_csum enabled.");
+                        return -ENOTTY;
+                }
+
                 err = mnt_want_write_file(filp);
                 if (err)
                         return err;