block_stream command stalls

[mcpacino]

block_stream command stalls near finishing.
I tried 1.7.1, 2.0.0 and the master versions. All of them stalled.
But the 1.1.2 could finish the job.

Here is how to reproduce it:

$ sudo $QEMU \
-enable-kvm -cpu qemu64 -m 1024 \
-monitor stdio \
-drive file=./i1,if=none,id=drive_0,cache=none,aio=native -device virtio-blk-pci,drive=drive_0,bus=pci.0,addr=0x5 \

QEMU 2.0.50 monitor - type 'help' for more information
(qemu) VNC server running on `127.0.0.1:5900'
(qemu) snapshot_blkdev drive_0 s1
Formatting 's1', fmt=qcow2 size=26843545600 backing_file='./i1' backing_fmt='qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
(qemu) block_stream drive_0
(qemu) info block-jobs
Streaming device drive_0: Completed 400818176 of 26843545600 bytes, speed limit 0 bytes/s
(qemu) info block-jobs
Streaming device drive_0: Completed 904396800 of 26843545600 bytes, speed limit 0 bytes/s
(qemu) info block-jobs
Streaming device drive_0: Completed 23401070592 of 26843545600 bytes, speed limit 0 bytes/s
(qemu) info block-jobs
Streaming device drive_0: Completed 26513768448 of 26843545600 bytes, speed limit 0 bytes/s
(qemu) main-loop: WARNING: I/O thread spun for 1000 iterations
info block-jobs
Streaming device drive_0: Completed 26841513984 of 26843545600 bytes, speed limit 0 bytes/s
(qemu) info block-jobs
Streaming device drive_0: Completed 26841513984 of 26843545600 bytes, speed limit 0 bytes/s
(qemu) info block-jobs
Streaming device drive_0: Completed 26841513984 of 26843545600 bytes, speed limit 0 bytes/s

#### here, the progress stopped at 26841513984 ####

$ qemu-img info i1
image: i1
file format: qcow2
virtual size: 25G (26843545600 bytes)
disk size: 1.0G
cluster_size: 2097152
Format specific information:
    compat: 1.1
    lazy refcounts: false

[Stefan Hajnoczi (stefanha)]

On Wed, May 21, 2014 at 09:55:26AM -0000, mcpacino wrote:
> block_stream command stalls near finishing.
> I tried 1.7.1, 2.0.0 and the master versions. All of them stalled.
> But the 1.1.2 could finish the job.

Can you still reproduce this on qemu.git/master?

$ qemu-system-x86_64 -enable-kvm -m 1024 -cpu host -drive if=virtio,cache=none,file=test.img,id=drive_1
...
(qemu) info block-jobs
Streaming device drive0: Completed 3115843584 of 8589934592 bytes, speed limit 0 bytes/s
(qemu) info block-jobs
Streaming device drive0: Completed 3171942400 of 8589934592 bytes, speed limit 0 bytes/s
(qemu) info block-jobs
No active jobs

[mcpacino (mcpacino)]

To Stefan:

yes, I can reproduce this on qemu.git/master.

Actually, I've found the cause of this bug and sent a patch to qemu-devel mailing list a few days ago:
http://lists.nongnu.org/archive/html/qemu-devel/2014-05/msg05777.html

It's very kind of you helping review the patch and give some comments.

Thanks.

Cong Meng.

[Thomas Huth (th-huth)]

Triaging old bug tickets... can you still reproduce this issue with the latest version of QEMU? Or could we close this ticket nowadays?

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]