On Wed, Apr 6, 2022 at 11:05 PM Christoph Hellwig <hch@xxxxxx> wrote: > > Add a helper to query the number of sectors support per each discard bio > based on the block device and use this helper to stop various places from > poking into the request_queue to see if discard is supported and if so how > much. This mirrors what is done e.g. for write zeroes as well. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- ... > diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c > index 16e775bcf4a7c..7d510e4231713 100644 > --- a/drivers/target/target_core_device.c > +++ b/drivers/target/target_core_device.c > @@ -829,9 +829,7 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) > } > > /* > - * Check if the underlying struct block_device request_queue supports > - * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM > - * in ATA and we need to set TPE=1 > + * Check if the underlying struct block_device request_queue supports disard. > */ Here was a typo: s/disard/discard/ On Thu, Apr 7, 2022 at 12:19 AM Andreas Gruenbacher <agruenba@xxxxxxxxxx> wrote: > If I'm misreading things, could you please document that > bdev_max_discard_sectors() != 0 implies that discard is supported? I got the same impression. Checking the discard support with bdev_max_discard_sectors() != 0 seems a bit unclear than before. Thanks, Ryusuke Konishi