summary refs log tree commit diff stats
path: root/results/classifier/118/all/1708442
diff options
context:
space:
mode:
Diffstat (limited to 'results/classifier/118/all/1708442')
-rw-r--r--results/classifier/118/all/1708442367
1 files changed, 367 insertions, 0 deletions
diff --git a/results/classifier/118/all/1708442 b/results/classifier/118/all/1708442
new file mode 100644
index 000000000..bdb2550cb
--- /dev/null
+++ b/results/classifier/118/all/1708442
@@ -0,0 +1,367 @@
+device: 0.925
+user-level: 0.921
+register: 0.915
+performance: 0.898
+permissions: 0.897
+debug: 0.897
+graphic: 0.895
+virtual: 0.890
+files: 0.883
+mistranslation: 0.879
+hypervisor: 0.877
+ppc: 0.875
+architecture: 0.875
+TCG: 0.874
+KVM: 0.871
+arm: 0.869
+risc-v: 0.867
+x86: 0.861
+semantic: 0.860
+assembly: 0.860
+vnc: 0.847
+VMM: 0.845
+PID: 0.838
+socket: 0.827
+peripherals: 0.827
+boot: 0.816
+i386: 0.803
+network: 0.796
+kernel: 0.784
+
+Crash(assert) during reading  image from http url through qemu-nbd
+
+Description:
+During reading image from nbd device mounted by qemu-nbd server with url backend I/O error happens
+"blk_update_request: I/O error, dev nbd0, sector 42117" dmesg. After some investigation I found that qemu-nbd server aborts in aio_co_enter() assert in util/async.c:468.
+
+
+Steps to reproduce:
+
+1) sudo go run qemu-nbd-bug-report/qemu-nbd-bug.go (see qemu-nbd-bug-report.tar.gz)
+
+or try directly
+
+1) qemu-nbd -c /dev/nbd0 -r -v --aio=native -f qcow2 json:{"file.driver":"http","file.url":"http://localhost:9666/image","file.readahead":3276800
+2) try read whole nbd device while error in dmesg appears x
+
+Versions:
+
+1) qemu built from sources(/configure --target-list=x86_64-softmmu --disable-user --enable-curl --enable-linux-aio --enable-virtfs --enable-debug --disable-pie
+, top commit 5619c179057e24195ff19c8fe6d6a6cbcb16ed28):
+
+qemu-nbd -v
+qemu-nbd 2.9.90 (v2.10.0-rc0-67-g5619c17)
+
+2) libcurl(built from sources, top commit 1767adf4399bb3be29121435e1bb1cc2bc05f7bf):
+
+curl -V
+curl 7.55.0-DEV (Linux) libcurl/7.55.0-DEV OpenSSL/1.0.2g zlib/1.2.8
+
+
+Backtrace:
+(gdb) bt
+#0  0x00007f7131426428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
+#1  0x00007f713142802a in __GI_abort () at abort.c:89
+#2  0x00007f713141ebd7 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x54c924 "self != co", 
+    file=file@entry=0x54c871 "util/async.c", line=line@entry=468, 
+    function=function@entry=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:92
+#3  0x00007f713141ec82 in __GI___assert_fail (assertion=0x54c924 "self != co", file=0x54c871 "util/async.c", line=468, 
+    function=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:101
+#4  0x00000000004fe6a2 in aio_co_enter (ctx=0xf0ddb0, co=0xf14650) at util/async.c:468
+#5  0x00000000004fe637 in aio_co_wake (co=0xf14650) at util/async.c:456
+#6  0x0000000000495c8a in curl_read_cb (ptr=0xf566d9, size=1, nmemb=16135, opaque=0xf1cb90) at block/curl.c:275
+#7  0x00007f713242ac24 in Curl_client_chop_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+#8  0x00007f713242ae03 in Curl_client_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+#9  0x00007f713244e1cf in readwrite_data () from /usr/lib/x86_64-linux-gnu/libcurl.so
+#10 0x00007f713244eb6f in Curl_readwrite () from /usr/lib/x86_64-linux-gnu/libcurl.so
+#11 0x00007f713245c1bb in multi_runsingle () from /usr/lib/x86_64-linux-gnu/libcurl.so
+#12 0x00007f713245d819 in multi_socket () from /usr/lib/x86_64-linux-gnu/libcurl.so
+#13 0x00007f713245e067 in curl_multi_socket_action () from /usr/lib/x86_64-linux-gnu/libcurl.so
+#14 0x0000000000497555 in curl_setup_preadv (bs=0xf16820, acb=0x7f712d379860) at block/curl.c:918
+#15 0x00000000004975fb in curl_co_preadv (bs=0xf16820, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/curl.c:935
+#16 0x000000000047730f in bdrv_driver_preadv (bs=0xf16820, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/io.c:836
+#17 0x0000000000477c1f in bdrv_aligned_preadv (child=0xf1be20, req=0x7f712d379a60, offset=6556160, bytes=512, align=1, 
+    qiov=0x7f712d379b40, flags=0) at block/io.c:1086
+#18 0x0000000000478109 in bdrv_co_preadv (child=0xf1be20, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/io.c:1180
+#19 0x0000000000437498 in qcow2_co_preadv (bs=0xf0fdc0, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+    at block/qcow2.c:1812
+#20 0x000000000047730f in bdrv_driver_preadv (bs=0xf0fdc0, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+    at block/io.c:836
+#21 0x0000000000477c1f in bdrv_aligned_preadv (child=0xf1c0d0, req=0x7f712d379d30, offset=21563904, bytes=512, align=1, 
+    qiov=0x7f712d379e80, flags=0) at block/io.c:1086
+#22 0x0000000000478109 in bdrv_co_preadv (child=0xf1c0d0, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+    at block/io.c:1180
+#23 0x00000000004645ad in blk_co_preadv (blk=0xf1be90, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+    at block/block-backend.c:991
+#24 0x00000000004646fa in blk_read_entry (opaque=0x7f712d379ea0) at block/block-backend.c:1038
+#25 0x000000000046481c in blk_prw (blk=0xf1be90, offset=21563904, 
+---Type <return> to continue, or q <return> to quit---
+    buf=0xf7f000 "2,NV\241t!\ti\312\vp\364\017Kl*\354\021\a\177\021\260\b\027\212\347\027\004\322\nG\340b\\\306pG\332\313\060\341;\002\360\063L\240\027T \211\341\305\022АE\230\356DǮ}\211\bx\016\a\b\313\350\316\064.\017\372\032-R\376z\261\263\350|cQ<\016S_L\340A\221\366~L#\001+\271\204\065~\327\023\027I\211\343\361\276zT$4\336\273ˏ\353ʪ\234\016_Z|TMk\"\370\002\363~\334\332.\a\375\265mӌ{/%\304֎\374sF<E\371\031o&\202\217\226\276>I\356\302\375F\340\332\324\021\202\232>\026\261\233\303tv\023\304\006\243\037\062BϏ\b\324rs\360'"..., bytes=512, co_entry=0x4646aa <blk_read_entry>, flags=0) at block/block-backend.c:1074
+#26 0x0000000000464f81 in blk_pread (blk=0xf1be90, offset=21563904, buf=0xf7f000, count=512) at block/block-backend.c:1227
+#27 0x00000000004906cb in nbd_trip (opaque=0xf5a940) at nbd/server.c:1380
+#28 0x000000000051c0a5 in coroutine_trampoline (i0=15812176, i1=0) at util/coroutine-ucontext.c:79
+#29 0x00007f713143b5d0 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
+#30 0x00007f712d47a770 in ?? ()
+#31 0x0000000000000000 in ?? ()
+Backtrace stopped: Cannot access memory at address 0x7f712d37a000
+
+
+
+On 08/03/2017 07:12 AM, Andrey Smetanin wrote:
+> Public bug reported:
+> 
+> Description:
+> During reading image from nbd device mounted by qemu-nbd server with url backend I/O error happens
+> "blk_update_request: I/O error, dev nbd0, sector 42117" dmesg. After some investigation I found that qemu-nbd server aborts in aio_co_enter() assert in util/async.c:468.
+> 
+
+Based on the backtrace, this looks to be a bug in the block/curl.c
+driver, rather than the nbd/ or block/nbd.c code.  If I'm right, it
+should be possible to reproduce the crash using qemu-io directly on the
+curl path, rather than adding the extra layer of an nbd client reading
+through qemu-nbd (then again, having the qemu-nbd layer may be what is
+allowing multiple parallel requests to hit the curl driver at once,
+while qemu-io is not quite as easy to provoke into performing
+complicated access patterns).
+
+> 
+> Steps to reproduce:
+> 
+> 1) sudo go run qemu-nbd-bug-report/qemu-nbd-bug.go (see qemu-nbd-bug-
+> report.tar.gz)
+> 
+> or try directly
+> 
+> 1) qemu-nbd -c /dev/nbd0 -r -v --aio=native -f qcow2 json:{"file.driver":"http","file.url":"http://localhost:9666/image","file.readahead":3276800
+
+Presumably, you've got something serving the file at port 9666?
+
+> 2) try read whole nbd device while error in dmesg appears x
+> 
+> Versions:
+> 
+> 1) qemu built from sources(/configure --target-list=x86_64-softmmu --disable-user --enable-curl --enable-linux-aio --enable-virtfs --enable-debug --disable-pie
+> , top commit 5619c179057e24195ff19c8fe6d6a6cbcb16ed28):
+> 
+> qemu-nbd -v
+> qemu-nbd 2.9.90 (v2.10.0-rc0-67-g5619c17)
+> 
+> 2) libcurl(built from sources, top commit
+> 1767adf4399bb3be29121435e1bb1cc2bc05f7bf):
+> 
+> curl -V
+> curl 7.55.0-DEV (Linux) libcurl/7.55.0-DEV OpenSSL/1.0.2g zlib/1.2.8
+> 
+> 
+> Backtrace:
+> (gdb) bt
+> #0  0x00007f7131426428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
+> #1  0x00007f713142802a in __GI_abort () at abort.c:89
+> #2  0x00007f713141ebd7 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x54c924 "self != co", 
+>     file=file@entry=0x54c871 "util/async.c", line=line@entry=468, 
+>     function=function@entry=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:92
+> #3  0x00007f713141ec82 in __GI___assert_fail (assertion=0x54c924 "self != co", file=0x54c871 "util/async.c", line=468, 
+>     function=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:101
+> #4  0x00000000004fe6a2 in aio_co_enter (ctx=0xf0ddb0, co=0xf14650) at util/async.c:468
+> #5  0x00000000004fe637 in aio_co_wake (co=0xf14650) at util/async.c:456
+> #6  0x0000000000495c8a in curl_read_cb (ptr=0xf566d9, size=1, nmemb=16135, opaque=0xf1cb90) at block/curl.c:275
+> #7  0x00007f713242ac24 in Curl_client_chop_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+> #8  0x00007f713242ae03 in Curl_client_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+> #9  0x00007f713244e1cf in readwrite_data () from /usr/lib/x86_64-linux-gnu/libcurl.so
+> #10 0x00007f713244eb6f in Curl_readwrite () from /usr/lib/x86_64-linux-gnu/libcurl.so
+> #11 0x00007f713245c1bb in multi_runsingle () from /usr/lib/x86_64-linux-gnu/libcurl.so
+> #12 0x00007f713245d819 in multi_socket () from /usr/lib/x86_64-linux-gnu/libcurl.so
+> #13 0x00007f713245e067 in curl_multi_socket_action () from /usr/lib/x86_64-linux-gnu/libcurl.so
+> #14 0x0000000000497555 in curl_setup_preadv (bs=0xf16820, acb=0x7f712d379860) at block/curl.c:918
+> #15 0x00000000004975fb in curl_co_preadv (bs=0xf16820, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/curl.c:935
+
+The backtrace is definitely pointing at curl as being the problem.
+
+-- 
+Eric Blake, Principal Software Engineer
+Red Hat, Inc.           +1-919-301-3266
+Virtualization:  qemu.org | libvirt.org
+
+
+
+03.08.2017, 17:01, "Eric Blake" <email address hidden>:
+> On 08/03/2017 07:12 AM, Andrey Smetanin wrote:
+>>  Public bug reported:
+>>
+>>  Description:
+>>  During reading image from nbd device mounted by qemu-nbd server with url backend I/O error happens
+>>  "blk_update_request: I/O error, dev nbd0, sector 42117" dmesg. After some investigation I found that qemu-nbd server aborts in aio_co_enter() assert in util/async.c:468.
+>
+> Based on the backtrace, this looks to be a bug in the block/curl.c
+> driver, rather than the nbd/ or block/nbd.c code. If I'm right, it
+> should be possible to reproduce the crash using qemu-io directly on the
+> curl path, rather than adding the extra layer of an nbd client reading
+> through qemu-nbd (then again, having the qemu-nbd layer may be what is
+> allowing multiple parallel requests to hit the curl driver at once,
+> while qemu-io is not quite as easy to provoke into performing
+> complicated access patterns).
+>
+>>  Steps to reproduce:
+>>
+>>  1) sudo go run qemu-nbd-bug-report/qemu-nbd-bug.go (see qemu-nbd-bug-
+>>  report.tar.gz)
+>>
+>>  or try directly
+>>
+>>  1) qemu-nbd -c /dev/nbd0 -r -v --aio=native -f qcow2 json:{"file.driver":"http","file.url":"http://localhost:9666/image","file.readahead":3276800
+>
+> Presumably, you've got something serving the file at port 9666?
+Yes, you are right. I'm using qemu-nbd-bug.go(see qemu-nbd-bug-report.tar.gz) script which does it.
+>
+>>  2) try read whole nbd device while error in dmesg appears x
+>>
+>>  Versions:
+>>
+>>  1) qemu built from sources(/configure --target-list=x86_64-softmmu --disable-user --enable-curl --enable-linux-aio --enable-virtfs --enable-debug --disable-pie
+>>  , top commit 5619c179057e24195ff19c8fe6d6a6cbcb16ed28):
+>>
+>>  qemu-nbd -v
+>>  qemu-nbd 2.9.90 (v2.10.0-rc0-67-g5619c17)
+>>
+>>  2) libcurl(built from sources, top commit
+>>  1767adf4399bb3be29121435e1bb1cc2bc05f7bf):
+>>
+>>  curl -V
+>>  curl 7.55.0-DEV (Linux) libcurl/7.55.0-DEV OpenSSL/1.0.2g zlib/1.2.8
+>>
+>>  Backtrace:
+>>  (gdb) bt
+>>  #0 0x00007f7131426428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
+>>  #1 0x00007f713142802a in __GI_abort () at abort.c:89
+>>  #2 0x00007f713141ebd7 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x54c924 "self != co",
+>>      file=file@entry=0x54c871 "util/async.c", line=line@entry=468,
+>>      function=function@entry=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:92
+>>  #3 0x00007f713141ec82 in __GI___assert_fail (assertion=0x54c924 "self != co", file=0x54c871 "util/async.c", line=468,
+>>      function=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:101
+>>  #4 0x00000000004fe6a2 in aio_co_enter (ctx=0xf0ddb0, co=0xf14650) at util/async.c:468
+>>  #5 0x00000000004fe637 in aio_co_wake (co=0xf14650) at util/async.c:456
+>>  #6 0x0000000000495c8a in curl_read_cb (ptr=0xf566d9, size=1, nmemb=16135, opaque=0xf1cb90) at block/curl.c:275
+>>  #7 0x00007f713242ac24 in Curl_client_chop_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>>  #8 0x00007f713242ae03 in Curl_client_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>>  #9 0x00007f713244e1cf in readwrite_data () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>>  #10 0x00007f713244eb6f in Curl_readwrite () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>>  #11 0x00007f713245c1bb in multi_runsingle () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>>  #12 0x00007f713245d819 in multi_socket () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>>  #13 0x00007f713245e067 in curl_multi_socket_action () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>>  #14 0x0000000000497555 in curl_setup_preadv (bs=0xf16820, acb=0x7f712d379860) at block/curl.c:918
+>>  #15 0x00000000004975fb in curl_co_preadv (bs=0xf16820, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/curl.c:935
+>
+> The backtrace is definitely pointing at curl as being the problem.
+>
+> --
+> Eric Blake, Principal Software Engineer
+> Red Hat, Inc. +1-919-301-3266
+> Virtualization: qemu.org | libvirt.org
+>
+> --
+> You received this bug notification because you are subscribed to the bug
+> report.
+> https://bugs.launchpad.net/bugs/1708442
+>
+> Title:
+>   Crash(assert) during reading image from http url through qemu-nbd
+>
+> Status in QEMU:
+>   New
+>
+> Bug description:
+>   Description:
+>   During reading image from nbd device mounted by qemu-nbd server with url backend I/O error happens
+>   "blk_update_request: I/O error, dev nbd0, sector 42117" dmesg. After some investigation I found that qemu-nbd server aborts in aio_co_enter() assert in util/async.c:468.
+>
+>   Steps to reproduce:
+>
+>   1) sudo go run qemu-nbd-bug-report/qemu-nbd-bug.go (see qemu-nbd-bug-
+>   report.tar.gz)
+>
+>   or try directly
+>
+>   1) qemu-nbd -c /dev/nbd0 -r -v --aio=native -f qcow2 json:{"file.driver":"http","file.url":"http://localhost:9666/image","file.readahead":3276800
+>   2) try read whole nbd device while error "blk_update_request: I/O error, dev nbd0, sector 42117" appears in dmesg
+>
+>   Versions:
+>
+>   1) qemu built from sources(/configure --target-list=x86_64-softmmu --disable-user --enable-curl --enable-linux-aio --enable-virtfs --enable-debug --disable-pie
+>   , top commit 5619c179057e24195ff19c8fe6d6a6cbcb16ed28):
+>
+>   qemu-nbd -v
+>   qemu-nbd 2.9.90 (v2.10.0-rc0-67-g5619c17)
+>
+>   2) libcurl(built from sources, top commit
+>   1767adf4399bb3be29121435e1bb1cc2bc05f7bf):
+>
+>   curl -V
+>   curl 7.55.0-DEV (Linux) libcurl/7.55.0-DEV OpenSSL/1.0.2g zlib/1.2.8
+>
+>   Backtrace:
+>   (gdb) bt
+>   #0 0x00007f7131426428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
+>   #1 0x00007f713142802a in __GI_abort () at abort.c:89
+>   #2 0x00007f713141ebd7 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x54c924 "self != co",
+>       file=file@entry=0x54c871 "util/async.c", line=line@entry=468,
+>       function=function@entry=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:92
+>   #3 0x00007f713141ec82 in __GI___assert_fail (assertion=0x54c924 "self != co", file=0x54c871 "util/async.c", line=468,
+>       function=0x54c980 <__PRETTY_FUNCTION__.24766> "aio_co_enter") at assert.c:101
+>   #4 0x00000000004fe6a2 in aio_co_enter (ctx=0xf0ddb0, co=0xf14650) at util/async.c:468
+>   #5 0x00000000004fe637 in aio_co_wake (co=0xf14650) at util/async.c:456
+>   #6 0x0000000000495c8a in curl_read_cb (ptr=0xf566d9, size=1, nmemb=16135, opaque=0xf1cb90) at block/curl.c:275
+>   #7 0x00007f713242ac24 in Curl_client_chop_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>   #8 0x00007f713242ae03 in Curl_client_write () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>   #9 0x00007f713244e1cf in readwrite_data () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>   #10 0x00007f713244eb6f in Curl_readwrite () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>   #11 0x00007f713245c1bb in multi_runsingle () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>   #12 0x00007f713245d819 in multi_socket () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>   #13 0x00007f713245e067 in curl_multi_socket_action () from /usr/lib/x86_64-linux-gnu/libcurl.so
+>   #14 0x0000000000497555 in curl_setup_preadv (bs=0xf16820, acb=0x7f712d379860) at block/curl.c:918
+>   #15 0x00000000004975fb in curl_co_preadv (bs=0xf16820, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/curl.c:935
+>   #16 0x000000000047730f in bdrv_driver_preadv (bs=0xf16820, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/io.c:836
+>   #17 0x0000000000477c1f in bdrv_aligned_preadv (child=0xf1be20, req=0x7f712d379a60, offset=6556160, bytes=512, align=1,
+>       qiov=0x7f712d379b40, flags=0) at block/io.c:1086
+>   #18 0x0000000000478109 in bdrv_co_preadv (child=0xf1be20, offset=6556160, bytes=512, qiov=0x7f712d379b40, flags=0) at block/io.c:1180
+>   #19 0x0000000000437498 in qcow2_co_preadv (bs=0xf0fdc0, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+>       at block/qcow2.c:1812
+>   #20 0x000000000047730f in bdrv_driver_preadv (bs=0xf0fdc0, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+>       at block/io.c:836
+>   #21 0x0000000000477c1f in bdrv_aligned_preadv (child=0xf1c0d0, req=0x7f712d379d30, offset=21563904, bytes=512, align=1,
+>       qiov=0x7f712d379e80, flags=0) at block/io.c:1086
+>   #22 0x0000000000478109 in bdrv_co_preadv (child=0xf1c0d0, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+>       at block/io.c:1180
+>   #23 0x00000000004645ad in blk_co_preadv (blk=0xf1be90, offset=21563904, bytes=512, qiov=0x7f712d379e80, flags=0)
+>       at block/block-backend.c:991
+>   #24 0x00000000004646fa in blk_read_entry (opaque=0x7f712d379ea0) at block/block-backend.c:1038
+>   #25 0x000000000046481c in blk_prw (blk=0xf1be90, offset=21563904,
+>   ---Type <return> to continue, or q <return> to quit---
+>       buf=0xf7f000 "2,NV\241t!\ti\312\vp\364\017Kl*\354\021\a\177\021\260\b\027\212\347\027\004\322\nG\340b\\\306pG\332\313\060\341;\002\360\063L\240\027T \211\341\305\022АE\230\356DǮ}\211\bx\016\a\b\313\350\316\064.\017\372\032-R\376z\261\263\350|cQ<\016S_L\340A\221\366~L#\001+\271\204\065~\327\023\027I\211\343\361\276zT$4\336\273ˏ\353ʪ\234\016_Z|TMk\"\370\002\363~\334\332.\a\375\265mӌ{/%\304֎\374sF<E\371\031o&\202\217\226\276>I\356\302\375F\340\332\324\021\202\232>\026\261\233\303tv\023\304\006\243\037\062BϏ\b\324rs\360'"..., bytes=512, co_entry=0x4646aa <blk_read_entry>, flags=0) at block/block-backend.c:1074
+>   #26 0x0000000000464f81 in blk_pread (blk=0xf1be90, offset=21563904, buf=0xf7f000, count=512) at block/block-backend.c:1227
+>   #27 0x00000000004906cb in nbd_trip (opaque=0xf5a940) at nbd/server.c:1380
+>   #28 0x000000000051c0a5 in coroutine_trampoline (i0=15812176, i1=0) at util/coroutine-ucontext.c:79
+>   #29 0x00007f713143b5d0 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
+>   #30 0x00007f712d47a770 in ?? ()
+>   #31 0x0000000000000000 in ?? ()
+>   Backtrace stopped: Cannot access memory at address 0x7f712d37a000
+>
+> To manage notifications about this bug go to:
+> https://bugs.launchpad.net/qemu/+bug/1708442/+subscriptions
+
+
+I've build qemu-nbd-bug.go into binary qemu-nbd-bug (go build qemu-nbd-bug.go), so to reproduce bug anyone may try:
+0) ensure image.img exists in current folder. image.img may be copied from "Qemu-nbd core dump and script to reproduce " attachment.
+1) sudo ./qemu-nbd-bug
+2) wait while binary aborting(panicking)
+3) check dmesg for error like "blk_update_request: I/O error, dev nbd0, sector 42117"
+4) check qemu-nbd core dump (since it's aborting due to assert in aio_co_enter(), util/async.c:468).
+
+I've attached patch which resolves bug, but actually it's just workaround and may be not unsafe, because it's just ignore assert.
+
+ping
+
+Looking through old bug tickets... is this still an issue with the latest version of QEMU? Or could we close this ticket nowadays?
+
+
+[Expired for QEMU because there has been no activity for 60 days.]
+