On 3/15/18 3:00 AM, Michael Tretter wrote: > On Wed, 28 Feb 2018 10:54:56 +0100, Michael Tretter wrote: >> If a file system is mounted on the nbd during a disconnect, resetting >> the size to 0, might change the block size and destroy the buffer_head >> mappings. This will cause a infinite loop when the file system looks for >> the buffer_heads for flushing. >> >> Only set the file size to 0, if we are the only opener of the nbd. >> >> Signed-off-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx> >> --- >> drivers/block/nbd.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c >> index 5f2a4240a204..0d1dbb60430b 100644 >> --- a/drivers/block/nbd.c >> +++ b/drivers/block/nbd.c >> @@ -1118,7 +1118,8 @@ static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *b >> if (ret) >> sock_shutdown(nbd); >> mutex_lock(&nbd->config_lock); >> - bd_set_size(bdev, 0); >> + if (bdev->bd_openers <= 1) >> + bd_set_size(bdev, 0); >> /* user requested, ignore socket errors */ >> if (test_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags)) >> ret = 0; > > Are there any comments on this patch? Josef? -- Jens Axboe
