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') 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 --- drivers/md/dm.c | 2 -- include/linux/device-mapper.h | 6 ------ 2 files changed, 8 deletions(-) (limited to 'include') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3763b2ce557b..a63efa2a46ae 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1664,8 +1664,6 @@ static blk_status_t __process_abnormal_io(struct clone_info *ci, case REQ_OP_WRITE_ZEROES: num_bios = ti->num_write_zeroes_bios; max_sectors = limits->max_write_zeroes_sectors; - if (ti->max_write_zeroes_granularity) - max_granularity = max_sectors; break; default: break; 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 --- drivers/md/dm.c | 2 -- include/linux/device-mapper.h | 6 ------ 2 files changed, 8 deletions(-) (limited to 'include') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index a63efa2a46ae..2abf2b6865ea 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1658,8 +1658,6 @@ static blk_status_t __process_abnormal_io(struct clone_info *ci, case REQ_OP_SECURE_ERASE: num_bios = ti->num_secure_erase_bios; max_sectors = limits->max_secure_erase_sectors; - if (ti->max_secure_erase_granularity) - max_granularity = max_sectors; break; case REQ_OP_WRITE_ZEROES: num_bios = ti->num_write_zeroes_bios; 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 --- drivers/md/dm-table.c | 33 ++++++++++++++++++++++++--------- include/linux/device-mapper.h | 5 +++++ 2 files changed, 29 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 33b7a1844ed4..eea41e38d87e 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -331,23 +331,15 @@ static int upgrade_mode(struct dm_dev_internal *dd, blk_mode_t new_mode, } /* - * Add a device to the list, or just increment the usage count if - * it's already present. - * * Note: the __ref annotation is because this function can call the __init * marked early_lookup_bdev when called during early boot code from dm-init.c. */ -int __ref dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode, - struct dm_dev **result) +int __ref dm_devt_from_path(const char *path, dev_t *dev_p) { int r; dev_t dev; unsigned int major, minor; char dummy; - struct dm_dev_internal *dd; - struct dm_table *t = ti->table; - - BUG_ON(!t); if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) { /* Extract the major/minor numbers */ @@ -363,6 +355,29 @@ int __ref dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode, if (r) return r; } + *dev_p = dev; + return 0; +} +EXPORT_SYMBOL(dm_devt_from_path); + +/* + * Add a device to the list, or just increment the usage count if + * it's already present. + */ +int dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode, + struct dm_dev **result) +{ + int r; + dev_t dev; + struct dm_dev_internal *dd; + struct dm_table *t = ti->table; + + BUG_ON(!t); + + r = dm_devt_from_path(path, &dev); + if (r) + return r; + if (dev == disk_devt(t->md->disk)) return -EINVAL; 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 --- drivers/md/dm-table.c | 7 +++++-- include/linux/device-mapper.h | 6 ++++++ 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index eea41e38d87e..dbd39b9722b9 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1050,6 +1050,7 @@ static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device * unsigned int min_pool_size = 0, pool_size; struct dm_md_mempools *pools; unsigned int bioset_flags = 0; + bool mempool_needs_integrity = t->integrity_supported; if (unlikely(type == DM_TYPE_NONE)) { DMERR("no table type is set, can't allocate mempools"); @@ -1074,6 +1075,8 @@ static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device * per_io_data_size = max(per_io_data_size, ti->per_io_data_size); min_pool_size = max(min_pool_size, ti->num_flush_bios); + + mempool_needs_integrity |= ti->mempool_needs_integrity; } pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size); front_pad = roundup(per_io_data_size, @@ -1083,13 +1086,13 @@ static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device * __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET; if (bioset_init(&pools->io_bs, pool_size, io_front_pad, bioset_flags)) goto out_free_pools; - if (t->integrity_supported && + if (mempool_needs_integrity && bioset_integrity_create(&pools->io_bs, pool_size)) goto out_free_pools; init_bs: if (bioset_init(&pools->bs, pool_size, front_pad, 0)) goto out_free_pools; - if (t->integrity_supported && + if (mempool_needs_integrity && bioset_integrity_create(&pools->bs, pool_size)) goto out_free_pools; 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