Re: [PATCH v6 4/5] dm-thin: Add REQ_OP_PROVISION support
From: Sarthak Kukreti <hidden>
Date: 2023-05-15 21:19:37
Also in:
dm-devel, linux-ext4, linux-fsdevel, lkml
On Fri, May 12, 2023 at 10:32 AM Mike Snitzer [off-list ref] wrote:
On Sat, May 06 2023 at 2:29P -0400, Sarthak Kukreti [off-list ref] wrote:quoted
dm-thinpool uses the provision request to provision blocks for a dm-thin device. dm-thinpool currently does not pass through REQ_OP_PROVISION to underlying devices. For shared blocks, provision requests will break sharing and copy the contents of the entire block. Additionally, if 'skip_block_zeroing' is not set, dm-thin will opt to zero out the entire range as a part of provisioning. Signed-off-by: Sarthak Kukreti <redacted> --- drivers/md/dm-thin.c | 70 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 66 insertions(+), 4 deletions(-)diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 2b13c949bd72..3f94f53ac956 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c...quoted
@@ -4114,6 +4171,8 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) * The pool uses the same discard limits as the underlying data * device. DM core has already set this up. */ + + limits->max_provision_sectors = pool->sectors_per_block;Just noticed that setting limits->max_provision_sectors needs to move above pool_io_hints code that sets up discards -- otherwise the early return from if (!pt->adjusted_pf.discard_enabled) will cause setting max_provision_sectors to be skipped. Here is a roll up of the fixes that need to be folded into this patch:
Ah right, thanks for pointing that out! I'll fold this into v7. Best Sarthak
quoted hunk ↗ jump to hunk
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 3f94f53ac956..90c8e36cb327 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c@@ -4151,6 +4151,8 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT); } + limits->max_provision_sectors = pool->sectors_per_block; + /* * pt->adjusted_pf is a staging area for the actual features to use. * They get transferred to the live pool in bind_control_target()@@ -4171,8 +4173,6 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits) * The pool uses the same discard limits as the underlying data * device. DM core has already set this up. */ - - limits->max_provision_sectors = pool->sectors_per_block; } static struct target_type pool_target = {@@ -4349,6 +4349,7 @@ static int thin_ctr(struct dm_target *ti, unsigned int argc, char **argv) ti->num_provision_bios = 1; ti->provision_supported = true; + ti->max_provision_granularity = true; mutex_unlock(&dm_thin_pool_table.mutex);