• Theodore Ts'o's avatar
    ext4: add max_dir_size_kb mount option · df981d03
    Theodore Ts'o authored
    Very large directories can cause significant performance problems, or
    perhaps even invoke the OOM killer, if the process is running in a
    highly constrained memory environment (whether it is VM's with a small
    amount of memory or in a small memory cgroup).
    So it is useful, in cloud server/data center environments, to be able
    to set a filesystem-wide cap on the maximum size of a directory, to
    ensure that directories never get larger than a sane size.  We do this
    via a new mount option, max_dir_size_kb.  If there is an attempt to
    grow the directory larger than max_dir_size_kb, the system call will
    return ENOSPC instead.
    Google-Bug-Id: 6863013
    Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>