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From: Matteo Croce <mcroce@linux.microsoft.com>
To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Jens Axboe <axboe@kernel.dk>,
	Christoph Hellwig <hch@infradead.org>
Cc: linux-kernel@vger.kernel.org,
	"Lennart Poettering" <lennart@poettering.net>,
	"Luca Boccassi" <bluca@debian.org>,
	"Alexander Viro" <viro@zeniv.linux.org.uk>,
	"Damien Le Moal" <damien.lemoal@wdc.com>,
	"Tejun Heo" <tj@kernel.org>,
	"Javier González" <javier@javigon.com>,
	"Niklas Cassel" <niklas.cassel@wdc.com>,
	"Johannes Thumshirn" <johannes.thumshirn@wdc.com>,
	"Hannes Reinecke" <hare@suse.de>,
	"Matthew Wilcox" <willy@infradead.org>,
	JeffleXu <jefflexu@linux.alibaba.com>
Subject: [PATCH v5 6/6] loop: raise media_change event
Date: Tue, 13 Jul 2021 01:05:30 +0200	[thread overview]
Message-ID: <20210712230530.29323-7-mcroce@linux.microsoft.com> (raw)
In-Reply-To: <20210712230530.29323-1-mcroce@linux.microsoft.com>

From: Matteo Croce <mcroce@microsoft.com>

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>
---
 drivers/block/loop.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f37b9e3d833c..f562609b6d53 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -731,6 +731,7 @@ 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;
@@ -1205,6 +1206,7 @@ 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);
@@ -1349,6 +1351,7 @@ 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) {
@@ -2325,6 +2328,8 @@ 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);
-- 
2.31.1


  parent reply	other threads:[~2021-07-12 23:07 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-12 23:05 [PATCH v5 0/5] block: add a sequence number to disks Matteo Croce
2021-07-12 23:05 ` [PATCH v5 1/6] block: add disk sequence number Matteo Croce
2021-07-12 23:05 ` [PATCH v5 2/6] block: export the diskseq in uevents Matteo Croce
2021-07-12 23:05 ` [PATCH v5 3/6] block: add ioctl to read the disk sequence number Matteo Croce
2021-07-12 23:05 ` [PATCH v5 4/6] block: export diskseq in sysfs Matteo Croce
2021-07-12 23:05 ` [PATCH v5 5/6] block: add a helper to raise a media changed event Matteo Croce
2021-07-12 23:05 ` Matteo Croce [this message]
2021-07-13  6:03   ` [PATCH v5 6/6] loop: raise media_change event Christoph Hellwig
2021-07-20 17:27 ` [PATCH v5 0/5] block: add a sequence number to disks Luca Boccassi
2021-07-22 11:41   ` Matteo Croce
2021-07-28 19:01   ` Lennart Poettering
2021-07-28 19:22 ` Jens Axboe

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