For extent-based files, you can perform DIO to holes, as mentioned in
the comments in ext4_ext_direct_IO. However, that function passes
DIO_SKIP_HOLES to __blockdev_direct_IO, which is *really* confusing to
the uninitiated reader. The key, here, is that the get_block function
passed in, ext4_get_block_write, completely ignores the create flag
that is passed to it (the create flag is passed in from the direct I/O
code, which uses the DIO_SKIP_HOLES flag to determine whether or not
it should be cleared).
This is a long-winded way of saying that the DIO_SKIP_HOLES flag is
ultimately ignored. So let's remove it.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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