Re: [PATCH 2/2] mkfs: Show progress during block discard

Darrick J. Wong
2019-11-21T21:59:24Z

On Thu, Nov 21, 2019 at 10:44:45PM +0100, Pavel Reichl wrote:
> Signed-off-by: Pavel Reichl <preichl@redhat.com>
> ---
> mkfs/xfs_mkfs.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index a02d6f66..07b8bd78 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -1248,6 +1248,7 @@ discard_blocks(dev_t dev, uint64_t nsectors)
> const uint64_t step = (uint64_t)2<<30;
> /* Sector size is 512 bytes */
> const uint64_t count = nsectors << 9;
> + uint64_t prev_done = (uint64_t) ~0;
>
> fd = libxfs_device_to_fd(dev);
> if (fd <= 0)
> @@ -1255,6 +1256,7 @@ discard_blocks(dev_t dev, uint64_t nsectors)
>
> while (offset < count) {
> uint64_t tmp_step = step;
> + uint64_t done = offset * 100 / count;
>
> if ((offset + step) > count)
> tmp_step = count - offset;
> @@ -1268,7 +1270,13 @@ discard_blocks(dev_t dev, uint64_t nsectors)
> return;
>
> offset += tmp_step;
> +
> + if (prev_done != done) {

Hmm... so this prints the status message every increase percentage
point, right?

> + prev_done = done;
> + fprintf(stderr, _("Discarding: %2lu%% done\n"), done);

This isn't an error, so why output to stderr?

FWIW if it's a tty you might consider ending that string with \r so the
status messages don't scroll off the screen. Or possibly only reporting
status if stdout is a tty?

--D

> + }
> }
> + fprintf(stderr, _("Discarding is done.\n"));
> }
>
> static __attribute__((noreturn)) void
> --
> 2.23.0
>