On 05/08/2020 11:10, Damien Le Moal wrote:
[...]
>
> May be something like this would do (not pretty...):
>
> diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
> index 999f54810926..fba312c8725d 100644
> --- a/drivers/scsi/sd.h
> +++ b/drivers/scsi/sd.h
> @@ -84,6 +84,7 @@ struct scsi_disk {
> u32 *zones_wp_offset;
> spinlock_t zones_wp_offset_lock;
> u32 *rev_wp_offset;
> + struct task_struct *rev_task;
> struct mutex rev_mutex;
> struct work_struct zone_wp_offset_work;
> char *zone_wp_update_buf;
> diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
> index 33221d8e9f8f..53f0489c3433 100644
> --- a/drivers/scsi/sd_zbc.c
> +++ b/drivers/scsi/sd_zbc.c
> @@ -69,7 +69,7 @@ static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
> if (ret)
> return ret;
>
> - if (sdkp->rev_wp_offset)
> + if (sdkp->rev_wp_offset && current == sdkp->rev_task)
> sdkp->rev_wp_offset[idx] = sd_zbc_get_zone_wp_offset(&zone);
>
> return 0;
> @@ -688,10 +688,13 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
> goto unlock;
> }
>
> + sdkp->rev_task = current;
> +
> ret = blk_revalidate_disk_zones(disk, sd_zbc_revalidate_zones_cb);
>
> kvfree(sdkp->rev_wp_offset);
> sdkp->rev_wp_offset = NULL;
> + sdkp->rev_task = NULL;
>
> if (ret) {
> sdkp->zone_blocks = 0;
>
>
> This is totally untested...
>
I agree it's not pretty but at least way more readable then what I did. Can't test
though, as I haven't managed to provoke the race yet.
