This is a note to let you know that I've just added the patch titled loop: Fix occasional uevent drop to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: loop-fix-occasional-uevent-drop.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c01a21b77722db0474bbcc4eafc8c4e0d8fed6d8 Mon Sep 17 00:00:00 2001 From: Petr Vorel <pvorel@xxxxxxx> Date: Thu, 12 Nov 2020 17:50:05 +0100 Subject: loop: Fix occasional uevent drop From: Petr Vorel <pvorel@xxxxxxx> commit c01a21b77722db0474bbcc4eafc8c4e0d8fed6d8 upstream. Commit 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") causes an occasional drop of loop device uevent, which are no longer triggered in loop_set_size() but in a different part of code. Bug is reproducible with LTP test uevent01 [1]: i=0; while true; do i=$((i+1)); echo "== $i ==" lsmod |grep -q loop && rmmod -f loop ./uevent01 || break done Put back triggering through code called in loop_set_size(). Fix required to add yet another parameter to set_capacity_revalidate_and_notify(). [1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/uevents/uevent01.c [hch: rebased on a different change to the prototype of set_capacity_revalidate_and_notify] Cc: stable@xxxxxxxxxxxxxxx # v5.9 Fixes: 716ad0986cbd ("loop: Switch to set_capacity_revalidate_and_notify") Reported-by: <ltp@xxxxxxxxxxxxxx> Signed-off-by: Petr Vorel <pvorel@xxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/block/loop.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -255,7 +255,8 @@ static void loop_set_size(struct loop_de bd_set_size(bdev, size << SECTOR_SHIFT); - set_capacity_revalidate_and_notify(lo->lo_disk, size, false); + if (!set_capacity_revalidate_and_notify(lo->lo_disk, size, false)) + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); } static inline int Patches currently in stable-queue which might be from pvorel@xxxxxxx are queue-5.9/block-add-a-return-value-to-set_capacity_revalidate_and_notify.patch queue-5.9/loop-fix-occasional-uevent-drop.patch