From: Matteo Croce <mcroce@microsoft.com>
Date: Tue, 13 Jul 2021 01:05:30 +0200
Subject: [PATCH] loop: raise media_change event
Git-commit: 9f65c489b68d42427dc0651488dd260d678f525d
Patch-mainline: v5.15-rc1
References: jsc#PED-1183
Make the loop device raise a DISK_MEDIA_CHANGE event on attach or detach.
# udevadm monitor -up |grep -e DISK_MEDIA_CHANGE -e DEVNAME &
# losetup -f zero
[ 7.454235] loop0: detected capacity change from 0 to 16384
DISK_MEDIA_CHANGE=1
DEVNAME=/dev/loop0
DEVNAME=/dev/loop0
DEVNAME=/dev/loop0
# losetup -f zero
[ 10.205245] loop1: detected capacity change from 0 to 16384
DISK_MEDIA_CHANGE=1
DEVNAME=/dev/loop1
DEVNAME=/dev/loop1
DEVNAME=/dev/loop1
# losetup -f zero2
[ 13.532368] loop2: detected capacity change from 0 to 40960
DISK_MEDIA_CHANGE=1
DEVNAME=/dev/loop2
DEVNAME=/dev/loop2
# losetup -D
DEVNAME=/dev/loop1
DISK_MEDIA_CHANGE=1
DEVNAME=/dev/loop1
DEVNAME=/dev/loop2
DISK_MEDIA_CHANGE=1
DEVNAME=/dev/loop2
DEVNAME=/dev/loop0
DISK_MEDIA_CHANGE=1
DEVNAME=/dev/loop0
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-7-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/block/loop.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a03ef5025f27..f8486d9b75a4 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -774,6 +774,7 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
goto out_err;
/* and ... switch */
+ disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE);
blk_mq_freeze_queue(lo->lo_queue);
mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);
lo->lo_backing_file = file;
@@ -1257,6 +1258,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
goto out_unlock;
}
+ disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE);
set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0);
INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn);
@@ -1410,6 +1412,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
partscan = lo->lo_flags & LO_FLAGS_PARTSCAN && bdev;
lo_number = lo->lo_number;
+ disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE);
out_unlock:
mutex_unlock(&lo->lo_mutex);
if (partscan) {
@@ -2386,6 +2389,8 @@ static int loop_add(int i)
disk->fops = &lo_fops;
disk->private_data = lo;
disk->queue = lo->lo_queue;
+ disk->events = DISK_EVENT_MEDIA_CHANGE;
+ disk->event_flags = DISK_EVENT_FLAG_UEVENT;
sprintf(disk->disk_name, "loop%d", i);
add_disk(disk);
mutex_unlock(&loop_ctl_mutex);
--
2.35.3