On Thu, Feb 1, 2018 at 7:03 AM, Douglas Gilbert <dgilbert@xxxxxxxxxxxx> wrote: > On 2018-01-30 07:22 AM, Dmitry Vyukov wrote: >> >> Uh, I've answered this a week ago, but did not notice that Doug >> dropped everybody from CC. Reporting to all. >> >> On Mon, Jan 22, 2018 at 8:16 PM, Douglas Gilbert <dgilbert@xxxxxxxxxxxx> >> wrote: >>> >>> On 2018-01-22 02:06 PM, Dmitry Vyukov wrote: >>>> >>>> >>>> On Mon, Jan 22, 2018 at 7:57 PM, Douglas Gilbert <dgilbert@xxxxxxxxxxxx> >>> >>> Please show me the output of 'lsscsi -g' on your test machine. >>> /dev/sg0 is often associated with /dev/sda which is often a SATA >>> SSD (or a virtualized one) that holds the root file system. >>> With the sg pass-through driver it is relatively easy to write >>> random (user provided data) over the root file system which will >>> almost certainly "root" the system. >> >> >> >> This is pretty standard qemu vm started with: >> >> qemu-system-x86_64 -hda wheezy.img -net user,host=10.0.2.10 -net nic >> -nographic -kernel arch/x86/boot/bzImage -append "console=ttyS0 >> root=/dev/sda earlyprintk=serial " -m 2G -smp 4 >> >> # lsscsi -g >> [0:0:0:0] disk ATA QEMU HARDDISK 0 /dev/sda /dev/sg0 > > > With lk 4.15.0-rc9 I can run your test program (with some additions, see > attachment) for 30 minutes against a scsi_debug simulated disk. You can > easily replicate this test just run 'modprobe scsi_debug' and a third > line should appear in your lsscsi output. The new device will most likely > be /dev/sg2 . > > With lk 4.15.0 (release) running against a SAS SSD (SEAGATE ST200FM0073), > the test has been running 20 minutes and counting without problems. That > is using a LSI HBA with the mpt3sas driver. > >> [1:0:0:0] cd/dvd QEMU QEMU DVD-ROM 2.0. /dev/sr0 /dev/sg1 >> >> # readlink /sys/class/scsi_generic/sg0 >> >> ../../devices/pci0000:00/0000:00:01.1/ata1/host0/target0:0:0/0:0:0:0/scsi_generic/sg0 >> >> # cat /sys/class/scsi_generic/sg0/device/vendor >> ATA > > > ^^^^^ > That subsystem is the culprit IMO, most likely libata. > > Until you can show this test failing on something other than an > ATA disk, then I will treat this issue as closed. Hi Doug, Why is bug in ATA not a bug? Is it long unused by everybody? I've got it by running qemu with default flags...
