From: Matteo Croce <mcroce@linux.microsoft.com>
To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>
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>,
"Christoph Hellwig" <hch@infradead.org>,
JeffleXu <jefflexu@linux.alibaba.com>
Subject: [PATCH v4 5/5] loop: raise media_change event
Date: Sun, 11 Jul 2021 19:54:15 +0200 [thread overview]
Message-ID: <20210711175415.80173-6-mcroce@linux.microsoft.com> (raw)
In-Reply-To: <20210711175415.80173-1-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 | 20 ++++++++++++++++++++
drivers/block/loop.h | 1 +
2 files changed, 21 insertions(+)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f37b9e3d833c..c632f9bd33ba 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -731,6 +731,8 @@ static int loop_change_fd(struct loop_device *lo, struct block_device *bdev,
goto out_err;
/* and ... switch */
+ lo->changed = true;
+ bdev_check_media_change(bdev);
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 +1207,9 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
goto out_unlock;
}
+ lo->changed = true;
+ bdev_check_media_change(bdev);
+
set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0);
INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn);
@@ -1349,6 +1354,8 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
partscan = lo->lo_flags & LO_FLAGS_PARTSCAN && bdev;
lo_number = lo->lo_number;
+ lo->changed = true;
+ bdev_check_media_change(bdev);
out_unlock:
mutex_unlock(&lo->lo_mutex);
if (partscan) {
@@ -2016,11 +2023,22 @@ static void lo_release(struct gendisk *disk, fmode_t mode)
mutex_unlock(&lo->lo_mutex);
}
+static unsigned int lo_check_events(struct gendisk *disk, unsigned int clearing)
+{
+ struct loop_device *lo = disk->private_data;
+ bool changed = lo->changed;
+
+ lo->changed = false;
+
+ return changed ? DISK_EVENT_MEDIA_CHANGE : 0;
+}
+
static const struct block_device_operations lo_fops = {
.owner = THIS_MODULE,
.open = lo_open,
.release = lo_release,
.ioctl = lo_ioctl,
+ .check_events = lo_check_events,
#ifdef CONFIG_COMPAT
.compat_ioctl = lo_compat_ioctl,
#endif
@@ -2325,6 +2343,8 @@ 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);
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index 1988899db63a..a2fdfd27e6a7 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -63,6 +63,7 @@ struct loop_device {
struct timer_list timer;
bool use_dio;
bool sysfs_inited;
+ bool changed;
struct request_queue *lo_queue;
struct blk_mq_tag_set tag_set;
--
2.31.1
next prev parent reply other threads:[~2021-07-11 17:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-11 17:54 [PATCH v4 0/5] block: add a sequence number to disks Matteo Croce
2021-07-11 17:54 ` [PATCH v4 1/5] block: add disk sequence number Matteo Croce
2021-07-12 6:25 ` Christoph Hellwig
2021-07-11 17:54 ` [PATCH v4 2/5] block: export the diskseq in uevents Matteo Croce
2021-07-12 6:26 ` Christoph Hellwig
2021-07-11 17:54 ` [PATCH v4 3/5] block: add ioctl to read the disk sequence number Matteo Croce
2021-07-12 6:28 ` Christoph Hellwig
2021-07-12 19:22 ` Elliott, Robert (Servers)
2021-07-12 23:25 ` Matteo Croce
2021-07-13 5:59 ` Christoph Hellwig
2021-07-11 17:54 ` [PATCH v4 4/5] block: export diskseq in sysfs Matteo Croce
2021-07-12 6:29 ` Christoph Hellwig
2021-07-11 17:54 ` Matteo Croce [this message]
2021-07-12 6:54 ` [PATCH v4 5/5] loop: raise media_change event Christoph Hellwig
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