• Andreas Dilger's avatar
    ext4: don't update s_rev_level if not required · c9e716eb
    Andreas Dilger authored
    Don't update the superblock s_rev_level during mount if it isn't
    actually necessary, only if superblock features are being set by
    the kernel.  This was originally added for ext3 since it always
    set the INCOMPAT_RECOVER and HAS_JOURNAL features during mount,
    but this is not needed since no journal mode was added to ext4.
    
    That will allow Geert to mount his 20-year-old ext2 rev 0.0 m68k
    filesystem, as a testament of the backward compatibility of ext4.
    
    Fixes: 0390131b ("ext4: Allow ext4 to run without a journal")
    Signed-off-by: default avatarAndreas Dilger <adilger@dilger.ca>
    Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    c9e716eb
super.c 171 KB