diff mbox series

nbd: don't call blk_mark_disk_dead nbd_clear_sock_ioctl

Message ID 20231003153106.1331363-1-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series nbd: don't call blk_mark_disk_dead nbd_clear_sock_ioctl | expand

Commit Message

Christoph Hellwig Oct. 3, 2023, 3:31 p.m. UTC
blk_mark_disk_dead is the proper interface to shut down a block
device, but it also makes the disk unusable forever.

nbd_clear_sock_ioctl on the other hand wants to shut down the file
system, but allow the block device to be used again when when connected
to another socket.  Switch nbd to use disk_force_media_change and
nbd_bdev_reset to go back to a behavior of the old __invalidate_device
call, with the added benefit of incrementing the device generation
as there is no guarantee the old content comes back when the device
is reconnected.

Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 0c1c9a27ce90 ("nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl")
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/nbd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Samuel Holland Oct. 3, 2023, 8:40 p.m. UTC | #1
On 2023-10-03 10:31 AM, Christoph Hellwig wrote:
> blk_mark_disk_dead is the proper interface to shut down a block
> device, but it also makes the disk unusable forever.
> 
> nbd_clear_sock_ioctl on the other hand wants to shut down the file
> system, but allow the block device to be used again when when connected
> to another socket.  Switch nbd to use disk_force_media_change and
> nbd_bdev_reset to go back to a behavior of the old __invalidate_device
> call, with the added benefit of incrementing the device generation
> as there is no guarantee the old content comes back when the device
> is reconnected.
> 
> Reported-by: Samuel Holland <samuel.holland@sifive.com>
> Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Fixes: 0c1c9a27ce90 ("nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl")
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/block/nbd.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Tested-by: Samuel Holland <samuel.holland@sifive.com>

Thanks for the fix!
Jens Axboe Oct. 4, 2023, 12:27 a.m. UTC | #2
On Tue, 03 Oct 2023 17:31:06 +0200, Christoph Hellwig wrote:
> blk_mark_disk_dead is the proper interface to shut down a block
> device, but it also makes the disk unusable forever.
> 
> nbd_clear_sock_ioctl on the other hand wants to shut down the file
> system, but allow the block device to be used again when when connected
> to another socket.  Switch nbd to use disk_force_media_change and
> nbd_bdev_reset to go back to a behavior of the old __invalidate_device
> call, with the added benefit of incrementing the device generation
> as there is no guarantee the old content comes back when the device
> is reconnected.
> 
> [...]

Applied, thanks!

[1/1] nbd: don't call blk_mark_disk_dead nbd_clear_sock_ioctl
      commit: 07a1141ff170ff5d4f9c4fbb0453727ab48096e5

Best regards,
Shinichiro Kawasaki Oct. 4, 2023, 4:14 a.m. UTC | #3
On Oct 03, 2023 / 17:31, Christoph Hellwig wrote:
> blk_mark_disk_dead is the proper interface to shut down a block
> device, but it also makes the disk unusable forever.
> 
> nbd_clear_sock_ioctl on the other hand wants to shut down the file
> system, but allow the block device to be used again when when connected
> to another socket.  Switch nbd to use disk_force_media_change and
> nbd_bdev_reset to go back to a behavior of the old __invalidate_device
> call, with the added benefit of incrementing the device generation
> as there is no guarantee the old content comes back when the device
> is reconnected.
> 
> Reported-by: Samuel Holland <samuel.holland@sifive.com>
> Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Fixes: 0c1c9a27ce90 ("nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl")
> Signed-off-by: Christoph Hellwig <hch@lst.de>

I also confirmed this patch fixes the issue that Samuel and I reported. Thanks!
diff mbox series

Patch

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index df1cd0f718b81c..800f131222fc8f 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1436,8 +1436,9 @@  static int nbd_start_device_ioctl(struct nbd_device *nbd)
 
 static void nbd_clear_sock_ioctl(struct nbd_device *nbd)
 {
-	blk_mark_disk_dead(nbd->disk);
 	nbd_clear_sock(nbd);
+	disk_force_media_change(nbd->disk);
+	nbd_bdev_reset(nbd);
 	if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF,
 			       &nbd->config->runtime_flags))
 		nbd_config_put(nbd);