• Christoph Hellwig's avatar
    xfs: remove the i_new_size field in struct xfs_inode · 2813d682
    Christoph Hellwig authored
    Now that we use the VFS i_size field throughout XFS there is no need for the
    i_new_size field any more given that the VFS i_size field gets updated
    in ->write_end before unlocking the page, and thus is always uptodate when
    writeback could see a page.  Removing i_new_size also has the advantage that
    we will never have to trim back di_size during a failed buffered write,
    given that it never gets updated past i_size.
    
    Note that currently the generic direct I/O code only updates i_size after
    calling our end_io handler, which requires a small workaround to make
    sure di_size actually makes it to disk.  I hope to fix this properly in
    the generic code.
    
    A downside is that we lose the support for parallel non-overlapping O_DIRECT
    appending writes that recently was added.  I don't think keeping the complex
    and fragile i_new_size infrastructure for this is a good tradeoff - if we
    really care about parallel appending writers we should investigate turning
    the iolock into a range lock, which would also allow for parallel
    non-overlapping buffered writers.
    Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
    Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
    Signed-off-by: default avatarBen Myers <bpm@sgi.com>
    2813d682
xfs_inode.h 19.6 KB