Commit fdfb4c8c authored by Mike Snitzer's avatar Mike Snitzer

dm thin: set minimum_io_size to pool's data block size

Before, if the block layer's limit stacking didn't establish an
optimal_io_size that was compatible with the thin-pool's data block size
we'd set optimal_io_size to the data block size and minimum_io_size to 0
(which the block layer adjusts to be physical_block_size).

Update pool_io_hints() to set both minimum_io_size and optimal_io_size
to the thin-pool's data block size.  This fixes an issue reported where
mkfs.xfs would create more XFS Allocation Groups on thinp volumes than
on a normal linear LV of comparable size, see: default avatarChris Murphy <>
Signed-off-by: default avatarMike Snitzer <>
parent 298a9fa0
......@@ -3177,7 +3177,7 @@ static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
if (io_opt_sectors < pool->sectors_per_block ||
do_div(io_opt_sectors, pool->sectors_per_block)) {
blk_limits_io_min(limits, 0);
blk_limits_io_min(limits, pool->sectors_per_block << SECTOR_SHIFT);
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
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