• Darrick J. Wong's avatar
    xfs: fix PAGE_MASK usage in xfs_free_file_space · a579121f
    Darrick J. Wong authored
    In commit e53c4b59, I *tried* to teach xfs to force writeback when we
    fzero/fpunch right up to EOF so that if EOF is in the middle of a page,
    the post-EOF part of the page gets zeroed before we return to userspace.
    Unfortunately, I missed the part where PAGE_MASK is ~(PAGE_SIZE - 1),
    which means that we totally fail to zero if we're fpunching and EOF is
    within the first page.  Worse yet, the same PAGE_MASK thinko plagues the
    filemap_write_and_wait_range call, so we'd initiate writeback of the
    entire file, which (mostly) masked the thinko.
    
    Drop the tricky PAGE_MASK and replace it with correct usage of PAGE_SIZE
    and the proper rounding macros.
    
    Fixes: e53c4b59 ("xfs: ensure post-EOF zeroing happens after zeroing part of a file")
    Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    a579121f
xfs_bmap_util.c 50.1 KB