• Theodore Ts'o's avatar
    ext4: fix check to prevent initializing reserved inodes · 50122847
    Theodore Ts'o authored
    Commit 8844618d: "ext4: only look at the bg_flags field if it is
    valid" will complain if block group zero does not have the
    EXT4_BG_INODE_ZEROED flag set.  Unfortunately, this is not correct,
    since a freshly created file system has this flag cleared.  It gets
    almost immediately after the file system is mounted read-write --- but
    the following somewhat unlikely sequence will end up triggering a
    false positive report of a corrupted file system:
    
       mkfs.ext4 /dev/vdc
       mount -o ro /dev/vdc /vdc
       mount -o remount,rw /dev/vdc
    
    Instead, when initializing the inode table for block group zero, test
    to make sure that itable_unused count is not too large, since that is
    the case that will result in some or all of the reserved inodes
    getting cleared.
    
    This fixes the failures reported by Eric Whiteney when running
    generic/230 and generic/231 in the the nojournal test case.
    
    Fixes: 8844618d ("ext4: only look at the bg_flags field if it is valid")
    Reported-by: default avatarEric Whitney <enwlinux@gmail.com>
    Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
    50122847
super.c 169 KB