On Tue, Dec 10, 2019 at 12:48:07PM +0100, Pavel Reichl wrote:
> Some users are not happy about the BLKDISCARD taking too long and at the same
> time not being informed about that - so they think that the command actually
> hung.
>
> This commit changes code so that progress reporting is possible and also typing
> the ^C will cancel the ongoing BLKDISCARD.
>
> Signed-off-by: Pavel Reichl <preichl@xxxxxxxxxx>
> ---
> Changelog:
> V4: Limit the reporting about discarding to a single line
>
> mkfs/xfs_mkfs.c | 50 ++++++++++++++++++++++++++++++++++++-------------
> 1 file changed, 37 insertions(+), 13 deletions(-)
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 18338a61..4bfdebf6 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -1240,17 +1240,40 @@ done:
> }
>
> static void
> -discard_blocks(dev_t dev, uint64_t nsectors)
> +discard_blocks(dev_t dev, uint64_t nsectors, int quiet)
If you /do/ decide to make @quiet a global then please make it bool.
That's material for a separate patch though...
...this looks reasonable enough to me;
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> {
> - int fd;
> + int fd;
> + uint64_t offset = 0;
> + /* Discard the device 2G at a time */
> + const uint64_t step = 2ULL << 30;
> + const uint64_t count = BBTOB(nsectors);
>
> - /*
> - * We intentionally ignore errors from the discard ioctl. It is
> - * not necessary for the mkfs functionality but just an optimization.
> - */
> fd = libxfs_device_to_fd(dev);
> - if (fd > 0)
> - platform_discard_blocks(fd, 0, nsectors << 9);
> + if (fd <= 0)
> + return;
> + if (!quiet) {
> + printf("Discarding blocks...");
> + fflush(stdout);
> + }
> +
> + /* The block discarding happens in smaller batches so it can be
> + * interrupted prematurely
> + */
> + while (offset < count) {
> + uint64_t tmp_step = min(step, count - offset);
> +
> + /*
> + * We intentionally ignore errors from the discard ioctl. It is
> + * not necessary for the mkfs functionality but just an
> + * optimization. However we should stop on error.
> + */
> + if (platform_discard_blocks(fd, offset, tmp_step))
> + return;
> +
> + offset += tmp_step;
> + }
> + if (!quiet)
> + printf("Done.\n");
> }
>
> static __attribute__((noreturn)) void
> @@ -2507,18 +2530,19 @@ open_devices(
>
> static void
> discard_devices(
> - struct libxfs_xinit *xi)
> + struct libxfs_xinit *xi,
> + int quiet)
> {
> /*
> * This function has to be called after libxfs has been initialized.
> */
>
> if (!xi->disfile)
> - discard_blocks(xi->ddev, xi->dsize);
> + discard_blocks(xi->ddev, xi->dsize, quiet);
> if (xi->rtdev && !xi->risfile)
> - discard_blocks(xi->rtdev, xi->rtsize);
> + discard_blocks(xi->rtdev, xi->rtsize, quiet);
> if (xi->logdev && xi->logdev != xi->ddev && !xi->lisfile)
> - discard_blocks(xi->logdev, xi->logBBsize);
> + discard_blocks(xi->logdev, xi->logBBsize, quiet);
> }
>
> static void
> @@ -3749,7 +3773,7 @@ main(
> * All values have been validated, discard the old device layout.
> */
> if (discard && !dry_run)
> - discard_devices(&xi);
> + discard_devices(&xi, quiet);
>
> /*
> * we need the libxfs buffer cache from here on in.
> --
> 2.23.0
>
