diff mbox series

[2/2] block: stack max_user_sectors

Message ID 20240523182618.602003-3-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [1/2] sd: also set max_user_sectors when setting max_sectors | expand

Commit Message

Christoph Hellwig May 23, 2024, 6:26 p.m. UTC
The max_user_sectors is one of the three factors determining the actual
max_sectors limit for READ/WRITE requests.  Because of that it needs to
be stacked at least for the device mapper multi-path case where requests
are directly inserted on the lower device.  For SCSI disks this is
important because the sd driver actually sets it's own advisory limit
that is lower than max_hw_sectors based on the block limits VPD page.
While this is a bit odd an unusual, the same effect can happen if a
user or udev script tweaks the value manually.

Fixes: 4f563a64732d ("block: add a max_user_discard_sectors queue limit")
Reported-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@kernel.org>
---
 block/blk-settings.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Martin K. Petersen May 23, 2024, 6:54 p.m. UTC | #1
Christoph,

> The max_user_sectors is one of the three factors determining the actual
> max_sectors limit for READ/WRITE requests.  Because of that it needs to
> be stacked at least for the device mapper multi-path case where requests
> are directly inserted on the lower device.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
diff mbox series

Patch

diff --git a/block/blk-settings.c b/block/blk-settings.c
index a7fe8e90240a6e..7a672021daee6a 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -611,6 +611,8 @@  int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 	unsigned int top, bottom, alignment, ret = 0;
 
 	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);
+	t->max_user_sectors = min_not_zero(t->max_user_sectors,
+			b->max_user_sectors);
 	t->max_hw_sectors = min_not_zero(t->max_hw_sectors, b->max_hw_sectors);
 	t->max_dev_sectors = min_not_zero(t->max_dev_sectors, b->max_dev_sectors);
 	t->max_write_zeroes_sectors = min(t->max_write_zeroes_sectors,