On 3/16/22 18:44, John Garry wrote:
> In commit edb854a3680b ("scsi: core: Reallocate device's budget map on
> queue depth change"), the sbitmap for the device budget map may be
> reallocated after the slave device depth is configured.
>
> When the sbitmap is reallocated we use the result from
> scsi_device_max_queue_depth() for the sbitmap size, but don't resize to
> match the actual device queue depth.
>
> Fix by resizing the sbitmap after reallocating the budget sbitmap. We do
> this instead of init'ing the sbitmap to the device queue depth as the user
> may want to change the queue depth later via sysfs or other.
>
> Fixes: edb854a3680b ("scsi: core: Reallocate device's budget map on queue depth change")
> Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
> Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
> Changes since v1 (apart from sending as a separate patch):
> - Add fixes and RB tag (thanks)
> - mention in commit message why we don't init sbitmap at queue depth
>
> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
> index f4e6c68ac99e..2ef78083f1ef 100644
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -223,6 +223,8 @@ static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev,
> int ret;
> struct sbitmap sb_backup;
>
> + depth = min_t(unsigned int, depth, scsi_device_max_queue_depth(sdev));
> +
> /*
> * realloc if new shift is calculated, which is caused by setting
> * up one new default queue depth after calling ->slave_configure
> @@ -245,6 +247,9 @@ static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev,
> scsi_device_max_queue_depth(sdev),
> new_shift, GFP_KERNEL,
> sdev->request_queue->node, false, true);
> + if (!ret)
> + sbitmap_resize(&sdev->budget_map, depth);
> +
> if (need_free) {
> if (ret)
> sdev->budget_map = sb_backup;
Tested-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
--
Damien Le Moal
Western Digital Research
