[PATCH] block: save user max_sectors limit

[Keith Busch <kbusch@meta.com>]

From: Keith Busch <kbusch@kernel.org>

The user can set the max_sectors limit to any valid value via sysfs
/sys/block/<dev>/queue/max_sectors_kb attribute. If the device limits
are ever rescanned, though, the limit reverts back to the potentially
artificially low BLK_DEF_MAX_SECTORS value.

Preserve the user's setting as long as it's valid and greater than the
default.

Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 block/blk-settings.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 0477c4d527fee..523348926a800 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -135,7 +135,8 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto
 	limits->max_hw_sectors = max_hw_sectors;
 
 	max_sectors = min_not_zero(max_hw_sectors, limits->max_dev_sectors);
-	max_sectors = min_t(unsigned int, max_sectors, BLK_DEF_MAX_SECTORS);
+	max_sectors = min_t(unsigned int, max_sectors, max(limits->max_sectors,
+							  BLK_DEF_MAX_SECTORS));
 	max_sectors = round_down(max_sectors,
 				 limits->logical_block_size >> SECTOR_SHIFT);
 	limits->max_sectors = max_sectors;
-- 
2.30.2