dm thin: do not expose non-zero discard limits if discards disabled (b60ab990) · Commits · 戴 / test

drivers/md/dm-thin.c

+11 −3

Original line number	Diff line number	Diff line
		@@ -2095,6 +2095,7 @@ static int pool_ctr(struct dm_target ti, unsigned argc, char *argv)
		* them down to the data device. The thin device's discard
		* processing will cause mappings to be removed from the btree.
		*/
		ti->discard_zeroes_data_unsupported = true;
		if (pf.discard_enabled && pf.discard_passdown) {
		ti->num_discard_bios = 1;

		@@ -2104,7 +2105,6 @@ static int pool_ctr(struct dm_target ti, unsigned argc, char *argv)
		* thin devices' discard limits consistent).
		*/
		ti->discards_supported = true;
		ti->discard_zeroes_data_unsupported = true;
		}
		ti->private = pt;

		@@ -2689,8 +2689,16 @@ static void pool_io_hints(struct dm_target ti, struct queue_limits limits)
		* They get transferred to the live pool in bind_control_target()
		* called from pool_preresume().
		*/
		if (!pt->adjusted_pf.discard_enabled)
		if (!pt->adjusted_pf.discard_enabled) {
		/*
		* Must explicitly disallow stacking discard limits otherwise the
		* block layer will stack them if pool's data device has support.
		* QUEUE_FLAG_DISCARD wouldn't be set but there is no way for the
		* user to see that, so make sure to set all discard limits to 0.
		*/
		limits->discard_granularity = 0;
		return;
		}

		disable_passdown_if_not_supported(pt);

		@@ -2826,10 +2834,10 @@ static int thin_ctr(struct dm_target ti, unsigned argc, char *argv)
		ti->per_bio_data_size = sizeof(struct dm_thin_endio_hook);

		/* In case the pool supports discards, pass them on. */
		ti->discard_zeroes_data_unsupported = true;
		if (tc->pool->pf.discard_enabled) {
		ti->discards_supported = true;
		ti->num_discard_bios = 1;
		ti->discard_zeroes_data_unsupported = true;
		/* Discard bios must be split on a block boundary */
		ti->split_discard_bios = true;
		}

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