From aaa53168cbcc486ca1927faac00bd99e81d4ff04 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 28 May 2024 13:32:34 +0200 Subject: dm: optimize flushes Device mapper sends flush bios to all the targets and the targets send it to the underlying device. That may be inefficient, for example if a table contains 10 linear targets pointing to the same physical device, then device mapper would send 10 flush bios to that device - despite the fact that only one bio would be sufficient. This commit optimizes the flush behavior. It introduces a per-target variable flush_bypasses_map - it is set when the target supports flush optimization - currently, the dm-linear and dm-stripe targets support it. When all the targets in a table have flush_bypasses_map, flush_bypasses_map on the table is set. __send_empty_flush tests if the table has flush_bypasses_map - and if it has, no flush bios are sent to the targets via the "map" method and the list dm_table->devices is iterated and the flush bios are sent to each member of the list. Signed-off-by: Mikulas Patocka Reviewed-by: Mike Snitzer Suggested-by: Yang Yang --- include/linux/device-mapper.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 82b2195efaca..3611b230d0aa 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -397,6 +397,21 @@ struct dm_target { * bio_set_dev(). NOTE: ideally a target should _not_ need this. */ bool needs_bio_set_dev:1; + + /* + * Set if the target supports flush optimization. If all the targets in + * a table have flush_bypasses_map set, the dm core will not send + * flushes to the targets via a ->map method. It will iterate over + * dm_table->devices and send flushes to the devices directly. This + * optimization reduces the number of flushes being sent when multiple + * targets in a table use the same underlying device. + * + * This optimization may be enabled on targets that just pass the + * flushes to the underlying devices without performing any other + * actions on the flush request. Currently, dm-linear and dm-stripe + * support it. + */ + bool flush_bypasses_map:1; }; void *dm_per_bio_data(struct bio *bio, size_t data_size); -- cgit v1.2.3 From 396a27e91265a6632be17bebacb6743f0b9447be Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Thu, 4 Jul 2024 15:45:00 +0200 Subject: dm: Remove max_write_zeroes_granularity The max_write_zeroes_granularity boolean of struct dm_target is used in __process_abnormal_io() but never set by any target. Remove this field and the dead code using it. Signed-off-by: Damien Le Moal Signed-off-by: Mikulas Patocka --- include/linux/device-mapper.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 3611b230d0aa..5b7e96653ec6 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -369,12 +369,6 @@ struct dm_target { */ bool max_secure_erase_granularity:1; - /* - * Set if this target requires that write_zeroes be split on - * 'max_write_zeroes_sectors' boundaries. - */ - bool max_write_zeroes_granularity:1; - /* * Set if we need to limit the number of in-flight bios when swapping. */ -- cgit v1.2.3 From 9d45db03acf9cee4f83148c403d105b1a38a0f23 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Thu, 4 Jul 2024 15:45:25 +0200 Subject: dm: Remove max_secure_erase_granularity The max_secure_erase_granularity boolean of struct dm_target is used in __process_abnormal_io() but never set by any target. Remove this field and the dead code using it. Signed-off-by: Damien Le Moal Signed-off-by: Mikulas Patocka --- include/linux/device-mapper.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 5b7e96653ec6..4ba2e73993bd 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -363,12 +363,6 @@ struct dm_target { */ bool max_discard_granularity:1; - /* - * Set if this target requires that secure_erases be split on - * 'max_secure_erase_sectors' boundaries. - */ - bool max_secure_erase_granularity:1; - /* * Set if we need to limit the number of in-flight bios when swapping. */ -- cgit v1.2.3 From a21f9edb13b0d8066775cbd5efa7261e41871182 Mon Sep 17 00:00:00 2001 From: Benjamin Marzinski Date: Thu, 4 Jul 2024 16:17:15 +0200 Subject: dm: factor out helper function from dm_get_device Factor out a helper function, dm_devt_from_path(), from dm_get_device() for use in dm targets. Signed-off-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka --- include/linux/device-mapper.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 4ba2e73993bd..384649a61bfa 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -179,6 +179,11 @@ int dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode, struct dm_dev **result); void dm_put_device(struct dm_target *ti, struct dm_dev *d); +/* + * Helper function for getting devices + */ +int dm_devt_from_path(const char *path, dev_t *dev_p); + /* * Information about a target type */ -- cgit v1.2.3 From 617069741dfbb141bc4574531a5dbbbad8ddf197 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 10 Jul 2024 20:53:12 +0200 Subject: dm: introduce the target flag mempool_needs_integrity This commit introduces the dm target flag mempool_needs_integrity. When the flag is set, device mapper will call bioset_integrity_create on it's bio sets. The target can then call bio_integrity_alloc on the bios allocated from the table's mempool. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- include/linux/device-mapper.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 384649a61bfa..1363f87fbba6 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -405,6 +405,12 @@ struct dm_target { * support it. */ bool flush_bypasses_map:1; + + /* + * Set if the target calls bio_integrity_alloc on bios received + * in the map method. + */ + bool mempool_needs_integrity:1; }; void *dm_per_bio_data(struct bio *bio, size_t data_size); -- cgit v1.2.3