Re: [Libguestfs] nbdkit error: "write reply: NBD_CMD_WRITE: Broken pipe"

> So I tried to reproduce this, and noticed something odd. It seems I can > disconnect the nbd device (nbd-client -d) while there are still requests > in flight: > > May 02 15:20:50 vostro.rath.org kernel: nbd1: detected capacity change from 0 to 52428800 > May 02 15:20:50 vostro.rath.org kernel: block nbd1: NBD_DISCONNECT > May 02 15:20:50 vostro.rath.org kernel: block nbd1: Disconnected due to user request. > May 02 15:20:50 vostro.rath.org kernel: block nbd1: shutting down sockets > May 02 15:20:50 vostro.rath.org kernel: I/O error, dev nbd1, sector 776 op 0x0:(READ) > flags 0x80700 phys_seg 29 prio class 0 > May 02 15:20:50 vostro.rath.org kernel: I/O error, dev nbd1, sector 776 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 > May 02 15:20:50 vostro.rath.org kernel: Buffer I/O error on dev nbd1, logical block 97, async page read > May 02 15:20:50 vostro.rath.org kernel: block nbd1: Attempted send on invalid socket > May 02 15:20:50 vostro.rath.org kernel: I/O error, dev nbd1, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0 > May 02 15:20:50 vostro.rath.org kernel: block nbd1: Attempted send on invalid socket > May 02 15:20:50 vostro.rath.org kernel: I/O error, dev nbd1, sector 0 op 0x1:(WRITE) flags 0x800 phys_seg 0 prio class 0 > > This was generated by running: > > $ nbd-client localhost /dev/nbd1 && mkfs.ext4 /dev/nbd1 && nbd-client -d > /dev/nbd1 > > Is that expected behavior? It's a bit unexpected to me. Adding Wouter to the thread - he might have an idea here, especially if there's a way to have "nbd-client -d" wait for pending requests to finish before disconnecting. I don't use the kernel client very much myself. We mostly use either libnbd or the qemu client.