[PATCH 5.10 090/593] loop: Fix missing discard support when using LOOP_CONFIGURE

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 02:40:26 EST

From: Kristian Klausen <kristian@xxxxxxxxxx>

commit 2b9ac22b12a266eb4fec246a07b504dd4983b16b upstream.

Without calling loop_config_discard() the discard flag and parameters
aren't set/updated for the loop device and worst-case they could
indicate discard support when it isn't the case (ex: if the
LOOP_SET_STATUS ioctl was used with a different file prior to

Cc: <stable@xxxxxxxxxxxxxxx> # 5.8.x-
Fixes: 3448914e8cc5 ("loop: Add LOOP_CONFIGURE ioctl")
Signed-off-by: Kristian Klausen <kristian@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210618115157.31452-1-kristian@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/block/loop.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1161,6 +1161,7 @@ static int loop_configure(struct loop_de
blk_queue_physical_block_size(lo->lo_queue, bsize);
blk_queue_io_min(lo->lo_queue, bsize);

+ loop_config_discard(lo);