Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHSA-2018:1104
Description of problem: QEMU hang after some sg_write_same operations with data plane enabled Version-Release number of selected component (if applicable): qemu-kvm-rhev-2.10.0-12.el7.x86_64 How reproducible: 100% Steps to Reproduce: 1. Create a 1G raw image on an XFS file system # qemu-img create -f raw /home/test.img 1G 2. Start qemu with a command-line like the following: -object iothread,id=iothread0 \ -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=0x3,iothread=iothread0 \ -drive id=drive1,if=none,format=raw,file=/home/kvm_autotest_root/images/rhel75-64-virtio-scsi.raw \ -device scsi-hd,drive=drive1 \ -drive file=/home/test.img,if=none,id=drive2,format=raw,werror=stop,rerror=stop,discard=on \ -device scsi-hd,drive=drive2,logical_block_size=4096 \ 3. Execute the following commands in guest: # yes | head -n2048 > buf # sg_write_same --in buf --num=32 --lba=80 /dev/sdb # sg_write_same --in /dev/zero --num=96 --lba=0 /dev/sdb # sg_write_same -U --in /dev/zero --num=16 --lba=0 /dev/sdb # sg_write_same --in buf --num=65536 --lba=131074 /dev/sdb # sg_write_same --in /dev/zero --num=65534 --lba=196608 /dev/sdb # sg_write_same --in /dev/zero --num=0 --lba=128 /dev/sd 4. shutdown guest via shell cmd. Actual results: QEMU hang at qemu_mutex_lock(). Expected results: QEMU should quit successfully after guest shutdown Additional info: 1. gdb info (gdb) bt full #0 0x00007f6614e2248d in __lll_lock_wait () at /lib64/libpthread.so.0 #1 0x00007f6614e1dd96 in _L_lock_870 () at /lib64/libpthread.so.0 #2 0x00007f6614e1dc8f in pthread_mutex_lock () at /lib64/libpthread.so.0 #3 0x000055cd62bdeb7f in qemu_mutex_lock (mutex=mutex@entry=0x55cd64ab1be0) at util/qemu-thread-posix.c:65 err = <optimized out> __PRETTY_FUNCTION__ = "qemu_mutex_lock" __func__ = "qemu_mutex_lock" #4 0x000055cd62bda7f9 in aio_context_acquire (ctx=ctx@entry=0x55cd64ab1b80) at util/async.c:502 #5 0x000055cd629d13d5 in iothread_stop_all () at iothread.c:305 ctx = 0x55cd64ab1b80 container = 0x55cd64ac6a80 bs = 0x55cd64af4000 it = {phase = BDRV_NEXT_BACKEND_ROOTS, blk = 0x55cd64a54500, bs = 0x0} #6 0x000055cd628bd964 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4807 i = <optimized out> snapshot = <optimized out> linux_boot = <optimized out> initrd_filename = <optimized out> kernel_filename = <optimized out> ---Type <return> to continue, or q <return> to quit--- kernel_cmdline = <optimized out> boot_order = <optimized out> boot_once = 0x55cd649f0718 "c" cyls = <optimized out> heads = <optimized out> secs = <optimized out> translation = <optimized out> opts = <optimized out> machine_opts = <optimized out> hda_opts = <optimized out> icount_opts = <optimized out> accel_opts = <optimized out> olist = <optimized out> optind = 43 optarg = 0x7fffc9948492 "scsi-hd,drive=drive2,logical_block_size=4096" loadvm = <optimized out> machine_class = 0x0 cpu_model = <optimized out> vga_model = 0x7fffc99481c3 "cirrus" qtest_chrdev = <optimized out> qtest_log = <optimized out> pid_file = <optimized out> ---Type <return> to continue, or q <return> to quit--- incoming = <optimized out> defconfig = <optimized out> userconfig = <optimized out> nographic = <optimized out> display_type = <optimized out> display_remote = <optimized out> log_mask = <optimized out> log_file = <optimized out> trace_file = <optimized out> maxram_size = <optimized out> ram_slots = <optimized out> vmstate_dump_file = <optimized out> main_loop_err = 0x0 err = 0x0 list_data_dirs = <optimized out> bdo_queue = {sqh_first = 0x0, sqh_last = 0x7fffc99470e0} __func__ = "main" __FUNCTION__ = "main" (gdb) 2. strace info: strace: Process 8375 attached futex(0x55cd64ab1be0, FUTEX_WAIT_PRIVATE, 2, NULL 3. qemu quit successfully without data plane enabled.