On Fri, 27 Jun 2014, Michael Büsch wrote:
> On Fri, 27 Jun 2014 08:48:01 -0700
> James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> > On Fri, 2014-06-27 at 17:34 +0200, Michael Büsch wrote:
> > > I tried the following patch:
> > >
> > > Index: linux/drivers/scsi/sd.c
> > > ===================================================================
> > > --- linux.orig/drivers/scsi/sd.c 2014-06-26 18:40:39.214696552 +0200
> > > +++ linux/drivers/scsi/sd.c 2014-06-27 15:52:30.776159456 +0200
> > > @@ -2440,7 +2440,7 @@ sd_read_cache_type(struct scsi_disk *sdk
> > > sdkp->RCD = 0;
> > > }
> > >
> > > - sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
> > > + sdkp->DPOFUA = 0;
> > > if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
> > > sd_first_printk(KERN_NOTICE, sdkp,
> > > "Uses READ/WRITE(6), disabling FUA\n");
> > >
> > >
> > > This obviously is not the correct thing to do, but it makes the disk usable:
> > >
> > > Jun 27 17:26:50 marge kernel: [ 523.909815] usb 2-1: new SuperSpeed USB device number 2 using xhci_hcd
> > > Jun 27 17:26:50 marge kernel: [ 523.929246] usb 2-1: New USB device found, idVendor=152d, idProduct=0567
> > > Jun 27 17:26:50 marge kernel: [ 523.929258] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> > > Jun 27 17:26:50 marge kernel: [ 523.929265] usb 2-1: Product: USB to ATA/ATAPI Bridge
> > > Jun 27 17:26:50 marge kernel: [ 523.929271] usb 2-1: Manufacturer: JMicron
> > > Jun 27 17:26:50 marge kernel: [ 523.929276] usb 2-1: SerialNumber: xxx
> > > Jun 27 17:26:50 marge kernel: [ 523.930999] usb-storage 2-1:1.0: USB Mass Storage device detected
> > > Jun 27 17:26:50 marge kernel: [ 523.931237] scsi12 : usb-storage 2-1:1.0
> > > Jun 27 17:26:51 marge kernel: [ 524.930451] scsi 12:0:0:0: Direct-Access JMicron Generic 0114 PQ: 0 ANSI: 6
> > > Jun 27 17:26:51 marge kernel: [ 524.931228] sd 12:0:0:0: Attached scsi generic sg3 type 0
> > > Jun 27 17:26:51 marge kernel: [ 524.932964] sd 12:0:0:0: [sdd] Spinning up disk...
> > > Jun 27 17:26:53 marge kernel: [ 525.937848] ..ready
> > > Jun 27 17:26:53 marge kernel: [ 526.942395] sd 12:0:0:0: [sdd] 976773168 512-byte logical blocks: (500 GB/465 GiB)
> > > Jun 27 17:26:53 marge kernel: [ 526.943037] sd 12:0:0:0: [sdd] Write Protect is off
> > > Jun 27 17:26:53 marge kernel: [ 526.943048] sd 12:0:0:0: [sdd] Mode Sense: 47 00 10 08
> > > Jun 27 17:26:53 marge kernel: [ 526.943662] sd 12:0:0:0: [sdd] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
> > > Jun 27 17:26:53 marge kernel: [ 526.987919] sdd: sdd1
> > > Jun 27 17:26:53 marge kernel: [ 526.990055] sd 12:0:0:0: [sdd] Attached SCSI disk
> > > Jun 27 17:27:29 marge kernel: [ 563.227849] EXT4-fs (sdd1): warning: mounting fs with errors, running e2fsck is recommended
> > > Jun 27 17:27:29 marge kernel: [ 563.228043] EXT4-fs (sdd1): mounted filesystem with ordered data mode. Opts: (null)
> > >
> > > (This is on another machine, but it shows the same behavior without the patch.)
> > >
> > > Does somebody have a hint for a real fix?
> >
> > I suspect the problem is in the USB bridge: The device reports FUA
> > support in its initial IDENTIFY, which gets translated to the correct
> > mode page bits, but when we send a READ/WRITE with the FUA bit set, the
> > bridge doesn't know how to translate it and gives us the error. There's
> > probably some way in USB to blacklist the bridge, but we need to
> > understand the consequences of the blacklist: The device is claiming a
> > writeback cache which means if it won't do either FUA or SYNC CACHE,
> > there's going to be a data integrity failure.
> >
> > The fact that your initial hack works suggests that sync cache is
> > accepted by it, so we probably just need a USB blacklist fixing the FUA
> > problem.
Michael, can you post the "lsusb -v" output for this device? I see it
is made by JMicron; they are notorious for buggy USB-ATA bridges.
Alan Stern
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