• Lukas Czerner's avatar
    mm: change invalidatepage prototype to accept length · d47992f8
    Lukas Czerner authored
    Currently there is no way to truncate partial page where the end
    truncate point is not at the end of the page. This is because it was not
    needed and the functionality was enough for file system truncate
    operation to work properly. However more file systems now support punch
    hole feature and it can benefit from mm supporting truncating page just
    up to the certain point.
    
    Specifically, with this functionality truncate_inode_pages_range() can
    be changed so it supports truncating partial page at the end of the
    range (currently it will BUG_ON() if 'end' is not at the end of the
    page).
    
    This commit changes the invalidatepage() address space operation
    prototype to accept range to be invalidated and update all the instances
    for it.
    
    We also change the block_invalidatepage() in the same way and actually
    make a use of the new length argument implementing range invalidation.
    
    Actual file system implementations will follow except the file systems
    where the changes are really simple and should not change the behaviour
    in any way .Implementation for truncate_page_range() which will be able
    to accept page unaligned ranges will follow as well.
    Signed-off-by: 's avatarLukas Czerner <lczerner@redhat.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Hugh Dickins <hughd@google.com>
    d47992f8
file.c 7.21 KB