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; -- 2.16.1
