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From: Fam Zheng <famz@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	linux-nvme@lists.infradead.org,
	virtualization@lists.linux-foundation.org,
	Keith Busch <keith.busch@intel.com>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Christoph Hellwig <hch@infradead.org>,
	Shaohua Li <shli@kernel.org>, Nitin Gupta <ngupta@vflare.org>,
	famz@redhat.com, Jiri Kosina <jikos@kernel.org>,
	linux-block@vger.kernel.org, "Ed L. Cashin" <ed.cashin@acm.org>,
	Jens Axboe <axboe@kernel.dk>,
	linux-raid@vger.kernel.org, David Woodhouse <dwmw2@infradead.org>,
	linux-mmc@vger.kernel.org, Minchan Kim <minchan@kernel.org>,
	linux-mtd@lists.infradead.org,
	Brian Norris <computersforpeace@gmail.com>,
	linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v2 03/12] virtio-blk: Generate uevent after attribute available
Date: Thu, 30 Jun 2016 09:59:44 +0800	[thread overview]
Message-ID: <20160630015953.6888-4-famz@redhat.com> (raw)
In-Reply-To: <20160630015953.6888-1-famz@redhat.com>

Userspace listens to the KOBJ_ADD uevent generated in add_disk. At that
point we haven't created the serial attribute file, therefore depending
on how fast udev reacts, the /dev/disk/by-id/ entry doesn't always get
created.

This race condition can be easily reproduced by hot plugging a number of
virtio-blk disks.

Also in systemd, there used to be a related workaround in udev rules
called 'WAIT_FOR="serial"', but it is removed in later versions.

Now let's generate a KOBJ_CHANGE event after the attributes are ready.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 drivers/block/virtio_blk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index f3a59f9..cd9a036 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -733,7 +733,7 @@ static int virtblk_probe(struct virtio_device *vdev)
 
 	virtio_device_ready(vdev);
 
-	add_disk(vblk->disk, true);
+	add_disk(vblk->disk, false);
 	err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
 	if (err)
 		goto out_del_disk;
@@ -746,6 +746,7 @@ static int virtblk_probe(struct virtio_device *vdev)
 					 &dev_attr_cache_type_ro);
 	if (err)
 		goto out_del_disk;
+	disk_gen_uevents(vblk->disk);
 	return 0;
 
 out_del_disk:
-- 
2.9.0

WARNING: multiple messages have this Message-ID (diff)
From: Fam Zheng <famz@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Jens Axboe <axboe@kernel.dk>, "Ed L. Cashin" <ed.cashin@acm.org>,
	Jiri Kosina <jikos@kernel.org>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Minchan Kim <minchan@kernel.org>, Nitin Gupta <ngupta@vflare.org>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Shaohua Li <shli@kernel.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Brian Norris <computersforpeace@gmail.com>,
	Keith Busch <keith.busch@intel.com>,
	linuxppc-dev@lists.ozlabs.org, linux-block@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org,
	linux-mtd@lists.infradead.org, linux-nvme@lists.infradead.org,
	Christoph Hellwig <hch@infradead.org>,
	famz@redhat.com
Subject: [PATCH v2 03/12] virtio-blk: Generate uevent after attribute available
Date: Thu, 30 Jun 2016 09:59:44 +0800	[thread overview]
Message-ID: <20160630015953.6888-4-famz@redhat.com> (raw)
In-Reply-To: <20160630015953.6888-1-famz@redhat.com>

Userspace listens to the KOBJ_ADD uevent generated in add_disk. At that
point we haven't created the serial attribute file, therefore depending
on how fast udev reacts, the /dev/disk/by-id/ entry doesn't always get
created.

This race condition can be easily reproduced by hot plugging a number of
virtio-blk disks.

Also in systemd, there used to be a related workaround in udev rules
called 'WAIT_FOR="serial"', but it is removed in later versions.

Now let's generate a KOBJ_CHANGE event after the attributes are ready.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 drivers/block/virtio_blk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index f3a59f9..cd9a036 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -733,7 +733,7 @@ static int virtblk_probe(struct virtio_device *vdev)
 
 	virtio_device_ready(vdev);
 
-	add_disk(vblk->disk, true);
+	add_disk(vblk->disk, false);
 	err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
 	if (err)
 		goto out_del_disk;
@@ -746,6 +746,7 @@ static int virtblk_probe(struct virtio_device *vdev)
 					 &dev_attr_cache_type_ro);
 	if (err)
 		goto out_del_disk;
+	disk_gen_uevents(vblk->disk);
 	return 0;
 
 out_del_disk:
-- 
2.9.0

WARNING: multiple messages have this Message-ID (diff)
From: famz@redhat.com (Fam Zheng)
Subject: [PATCH v2 03/12] virtio-blk: Generate uevent after attribute available
Date: Thu, 30 Jun 2016 09:59:44 +0800	[thread overview]
Message-ID: <20160630015953.6888-4-famz@redhat.com> (raw)
In-Reply-To: <20160630015953.6888-1-famz@redhat.com>

Userspace listens to the KOBJ_ADD uevent generated in add_disk. At that
point we haven't created the serial attribute file, therefore depending
on how fast udev reacts, the /dev/disk/by-id/ entry doesn't always get
created.

This race condition can be easily reproduced by hot plugging a number of
virtio-blk disks.

Also in systemd, there used to be a related workaround in udev rules
called 'WAIT_FOR="serial"', but it is removed in later versions.

Now let's generate a KOBJ_CHANGE event after the attributes are ready.

Signed-off-by: Fam Zheng <famz at redhat.com>
---
 drivers/block/virtio_blk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index f3a59f9..cd9a036 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -733,7 +733,7 @@ static int virtblk_probe(struct virtio_device *vdev)
 
 	virtio_device_ready(vdev);
 
-	add_disk(vblk->disk, true);
+	add_disk(vblk->disk, false);
 	err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
 	if (err)
 		goto out_del_disk;
@@ -746,6 +746,7 @@ static int virtblk_probe(struct virtio_device *vdev)
 					 &dev_attr_cache_type_ro);
 	if (err)
 		goto out_del_disk;
+	disk_gen_uevents(vblk->disk);
 	return 0;
 
 out_del_disk:
-- 
2.9.0

  parent reply	other threads:[~2016-06-30  1:59 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-30  1:59 [PATCH v2 00/12] gendisk: Generate uevent after attribute available Fam Zheng
2016-06-30  1:59 ` Fam Zheng
2016-06-30  1:59 ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 01/12] genhd: Add "gen_uevent" parameter to add_disk Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 02/12] genhd: Honor gen_uevent and add disk_gen_uevents Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  3:26   ` kbuild test robot
2016-06-30  3:26     ` kbuild test robot
2016-06-30  3:26     ` kbuild test robot
2016-06-30  1:59 ` Fam Zheng [this message]
2016-06-30  1:59   ` [PATCH v2 03/12] virtio-blk: Generate uevent after attribute available Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 04/12] axonrom: " Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30 22:10   ` Dan Williams
2016-06-30 22:10     ` Dan Williams
2016-06-30 22:10     ` Dan Williams
2016-07-01  1:03     ` Fam Zheng
2016-07-01  1:03       ` Fam Zheng
2016-07-01  1:03       ` Fam Zheng
2016-06-30 22:10   ` Dan Williams
2016-06-30  1:59 ` [PATCH v2 05/12] aoeblk: " Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-07-01  0:57   ` Ed Cashin
2016-07-01  0:57     ` Ed Cashin
2016-07-01  0:57     ` Ed Cashin
2016-07-01  0:57   ` Ed Cashin
2016-06-30  1:59 ` [PATCH v2 06/12] mtip32xx: " Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 07/12] pktcdvd: " Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 08/12] zram: " Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 09/12] md: " Fam Zheng
2016-06-30  1:59 ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 10/12] mmc: " Fam Zheng
2016-06-30  1:59 ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 11/12] mtd: " Fam Zheng
2016-06-30  1:59 ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  1:59 ` [PATCH v2 12/12] nvme: " Fam Zheng
2016-06-30  1:59 ` Fam Zheng
2016-06-30  1:59   ` Fam Zheng
2016-06-30  6:24 ` [PATCH v2 00/12] gendisk: " Christoph Hellwig
2016-06-30  6:24   ` Christoph Hellwig
2016-06-30  6:24   ` Christoph Hellwig
2016-06-30  6:24   ` Christoph Hellwig
2016-06-30  6:35   ` Fam Zheng
2016-06-30  6:35     ` Fam Zheng
2016-06-30  6:35     ` Fam Zheng
2016-06-30  6:38     ` Christoph Hellwig
2016-06-30  6:38       ` Christoph Hellwig
2016-06-30  6:38       ` Christoph Hellwig
2016-07-01  1:01       ` Fam Zheng
2016-07-01  1:01         ` Fam Zheng
2016-07-01  1:01         ` Fam Zheng
2016-07-01  1:29         ` Dan Williams
2016-07-01  1:29         ` Dan Williams
2016-07-01  1:29           ` Dan Williams
2016-07-01  1:29           ` Dan Williams
2016-07-01  1:29           ` Dan Williams

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