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    SubjectRe: why is the size of a directory always 1024b ?
    In <199906240233.WAA17909@jupiter.cs.uml.edu> Albert D. Cahalan (acahalan@cs.uml.edu) wrote:
    > David S. Miller writes:
    >> From: MURALI N <murali.n@tatainfotech.com>

    >>> I want to know if there is any significant reason why the
    >>> size of each directory ( ext2fs) is reported as 1024b ( or a
    >>> multiple of 1024).
    >>
    >> Because this is the "block size" of the filesystem, the directory
    >> space is allocated in units of this.

    > One could say the same for regular files, so this doen't really
    > explain why directory sizes are poorly reported.

    What's "correct size" for directory ? If I have 1MiB directory where ls will
    work few minutes but with only two entries in it ("." and "..") -- what's
    the size of this directory ? 16 bytes or 1MiB ? You can create such beast
    easily: just create few thousands of files in one directory and then remove
    all of them.

    > We do have linear directories that grow from beginning to end.

    Not always. HPFS and NTFS use B-trees and there are plans to do it in ext2fs
    as well...

    > An empty directory is something like 16 bytes for "." and "..".

    Not always (see above).

    > The kernel might as well report the fact, just as it reports a
    > regular file by actual content.

    Regular file does not have unused space in the middle of file (from filesystem
    viewpoint that is).

    > If inaccurate reporting really is OK, then it might as well be
    > derived from the block count. That gives an extra 4 bytes in the
    > inode for directories.





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