On Fri, Nov 10, 2017 at 11:45 AM, Dave Jiang <dave.ji...@intel.com> wrote:
> The size for mmap needs to be aligned to the region alignment. Add helper
> funciton to determine the actual size to be mmap'd.
>
> Signed-off-by: Dave Jiang <dave.ji...@intel.com>
> ---
> daxctl/io.c | 23 ++++++++++++++++++++++-
> 1 file changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/daxctl/io.c b/daxctl/io.c
> index 2f8cb4a..97a4169 100644
> --- a/daxctl/io.c
> +++ b/daxctl/io.c
> @@ -80,9 +80,26 @@ static bool is_stdinout(struct io_dev *io_dev)
> io_dev->fd == STDOUT_FILENO) ? true : false;
> }
>
> +static int get_mmap_size(struct io_dev *io_dev, size_t size, size_t
> *map_size)
> +{
> + unsigned long align;
> +
> + align = ndctl_dax_get_align(io_dev->dax);
> + if (align == ULLONG_MAX)
> + return -ERANGE;
> +
> + if (size <= align)
> + *map_size = align;
> + else
> + *map_size = (size / align) * align;
We have the ALIGN() macro in util/size.h for this.
> +
> + return 0;
> +}
> +
> static int setup_device(struct io_dev *io_dev, size_t size)
> {
> int flags, rc;
> + size_t map_size;
>
> if (is_stdinout(io_dev))
> return 0;
> @@ -104,8 +121,12 @@ static int setup_device(struct io_dev *io_dev, size_t
> size)
> if (!io_dev->is_dax)
> return 0;
>
> + rc = get_mmap_size(io_dev, size, &map_size);
> + if (rc < 0)
> + return rc;
> +
> flags = (io_dev->direction == IO_READ) ? PROT_READ : PROT_WRITE;
> - io_dev->mmap = mmap(NULL, size, flags, MAP_SHARED, io_dev->fd, 0);
> + io_dev->mmap = mmap(NULL, map_size, flags, MAP_SHARED, io_dev->fd, 0);
Why is offset 0 here? I would expect it to come from the command line
arguments and also use ALIGN_DOWN() to align to first aligned offset
before the target offset.
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