From c2e4cd57cfa1f627b786c764d185fff85fd12be9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:34 +0200 Subject: block: lift setting the readahead size into the block layer Drivers shouldn't really mess with the readahead size, as that is a VM concept. Instead set it based on the optimal I/O size by lifting the algorithm from the md driver when registering the disk. Also set bdi->io_pages there as well by applying the same scheme based on max_sectors. To ensure the limits work well for stacking drivers a new helper is added to update the readahead limits from the block limits, which is also called from disk_stack_limits. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Jan Kara Reviewed-by: Mike Snitzer Reviewed-by: Martin K. Petersen Acked-by: Coly Li Signed-off-by: Jens Axboe --- drivers/md/dm-table.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/md/dm-table.c') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 5edc3079e7c1..ef2757012f59 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1925,8 +1925,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } #endif - /* Allow reads to exceed readahead limits */ - q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9); + blk_queue_update_readahead(q); } unsigned int dm_table_get_num_targets(struct dm_table *t) -- cgit v1.2.3 From 1cb039f3dc1619eb795c54aad0a98fdb379b4237 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Sep 2020 08:51:38 +0200 Subject: bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag The BDI_CAP_STABLE_WRITES is one of the few bits of information in the backing_dev_info shared between the block drivers and the writeback code. To help untangling the dependency replace it with a queue flag and a superblock flag derived from it. This also helps with the case of e.g. a file system requiring stable writes due to its own checksumming, but not forcing it on other users of the block device like the swap code. One downside is that we an't support the stable_pages_required bdi attribute in sysfs anymore. It is replaced with a queue attribute which also is writable for easier testing. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe --- drivers/md/dm-table.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/md/dm-table.c') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index ef2757012f59..405d7cf10eb9 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1815,7 +1815,7 @@ static int device_requires_stable_pages(struct dm_target *ti, { struct request_queue *q = bdev_get_queue(dev->bdev); - return q && bdi_cap_stable_pages_required(q->backing_dev_info); + return q && blk_queue_stable_writes(q); } /* @@ -1900,9 +1900,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, * because they do their own checksumming. */ if (dm_table_requires_stable_pages(t)) - q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q); else - q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES; + blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q); /* * Determine whether or not this queue's I/O timings contribute -- cgit v1.2.3 From fa01b1e9733fd59ecb8b5b6d85dfb481d2025fbf Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 07:40:57 +0200 Subject: block: add a bdev_is_partition helper Add a littler helper to make the somewhat arcane bd_contains checks a little more obvious. Signed-off-by: Christoph Hellwig Acked-by: Ulf Hansson Signed-off-by: Jens Axboe --- drivers/md/dm-table.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/dm-table.c') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 405d7cf10eb9..12d909044c10 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -903,7 +903,7 @@ static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev, struct request_queue *q = bdev_get_queue(bdev); /* request-based cannot stack on partitions! */ - if (bdev != bdev->bd_contains) + if (bdev_is_partition(bdev)) return false; return queue_is_mq(q); -- cgit v1.2.3 From 6abc49468eeaad2dd481779906aaa29605139087 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Wed, 23 Sep 2020 16:06:52 -0400 Subject: dm: add support for REQ_NOWAIT and enable it for linear target Add DM target feature flag DM_TARGET_NOWAIT which advertises that target works with REQ_NOWAIT bios. Add dm_table_supports_nowait() and update dm_table_set_restrictions() to set/clear QUEUE_FLAG_NOWAIT accordingly. Signed-off-by: Konstantin Khlebnikov Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe --- drivers/md/dm-table.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'drivers/md/dm-table.c') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 12d909044c10..07c319e98581 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1748,6 +1748,33 @@ static bool dm_table_supports_write_zeroes(struct dm_table *t) return true; } +static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + struct request_queue *q = bdev_get_queue(dev->bdev); + + return q && !blk_queue_nowait(q); +} + +static bool dm_table_supports_nowait(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i = 0; + + while (i < dm_table_get_num_targets(t)) { + ti = dm_table_get_target(t, i++); + + if (!dm_target_supports_nowait(ti->type)) + return false; + + if (!ti->type->iterate_devices || + ti->type->iterate_devices(ti, device_not_nowait_capable, NULL)) + return false; + } + + return true; +} + static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1850,6 +1877,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, */ q->limits = *limits; + if (dm_table_supports_nowait(t)) + blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q); + else + blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q); + if (!dm_table_supports_discards(t)) { blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); /* Must also clear discard limits... */ -- cgit v1.2.3