On Wed, Dec 10, 2014 at 02:29:29AM -0800, Darrick J. Wong wrote:
> On Wed, Dec 10, 2014 at 02:15:14AM -0800, Darrick J. Wong wrote:
> > On Wed, Dec 10, 2014 at 01:04:58AM -0800, Darrick J. Wong wrote:
> > > On Wed, Dec 10, 2014 at 09:19:04AM +0100, Hans de Goede wrote:
> > > > Hi,
> > > >
> > > > On 09-12-14 20:31, Darrick J. Wong wrote:
> > > > >Hi,
> > > > >
> > > > >I have an Apricorn USB 3 disk dongle thing that claims to support UAS.
> > > > >However, the kernel crashes when I plug it in[1].
> > > >
> > > > Yes there are some known issues with uas error handling which are fixed
> > > > in 3.18, can you try with a 3.18 kernel please ?
> > >
> > > The crash pic was from 3.18.0, blk_mq disabled. I'll work on getting a fuller
> > > dmesg output. Looking at the code, it looks like we end up in
> > > queue_bulk_sg_tx() with a sg list that is shorter than num_sgs, so we fall off
> > > the end.
Well, there are (at least) two issues going on here. The first is that the
SCSI layer passes us zero-length READ10 commands, which is causing this crash.
Zero length means the sglist is empty, so the usb host has nothing to map, and
hence urb->num_mapped_sgs == 0 and the loop goes boom. I don't know what it
means to send a bulk URB with no buffers, so...
...then I took a tour of how SCSI LLDDs deal with zero-length read/write
commands. mpt2sas attaches a junk sg and pushes the command out. libata
detects zero-length READ/WRITE SCSI commands and completes the scsi command
without ever touching hardware. I wasn't able to get any of my parallel SCSI
disks to boot, so I could not try that.
The other problem is when I plug in a different disk (same mfg/model), READ
CAPACITY 16 intermittently returns the string "USBSUSBSUSBS", which of course
is garbage. The kernel then tries to use these values; fortunately, it rejects
a sector size of 1431519827 ("USBS") and sets the size to zero.
So, I can code up a couple of patches -- one to teach UAS how to deal with zero
length read and writes; and a second patch to set US_FL_IGNORE_UAS on Apricorn
bridges. I tried setting US_FL_NO_READ_CAPACITY_16, but for whatever reason
sd.c was still trying RC16.
--D
> > >
> > > (Alas it's now 1am here, so I'm going to bed. :/ )
> >
> > Eh, nuts to sleeping. dmesg produces this:
> >
> > [ 231.128074] usbcore: registered new interface driver usb-storage
> > [ 231.133822] usbcore: registered new interface driver uas
> > [ 252.121353] usb 2-4: new SuperSpeed USB device number 2 using xhci_hcd
> > [ 252.136927] scsi host6: uas
> > [ 252.141679] scsi 6:0:0:0: Direct-Access Apricorn 0128 PQ: 0 ANSI: 6
> > [ 252.145433] sd 6:0:0:0: Attached scsi generic sg2 type 0
> > [ 252.145525] sd 6:0:0:0: [sdc] 312581808 512-byte logical blocks: (160 GB/149 GiB)
> > [ 252.145527] sd 6:0:0:0: [sdc] 4096-byte physical blocks
> > [ 252.145891] sd 6:0:0:0: [sdc] Write Protect is off
> > [ 252.145973] sd 6:0:0:0: [sdc] No Caching mode page found
> > [ 252.145975] sd 6:0:0:0: [sdc] Assuming drive cache: write through
>
> Huh. 4096-byte physical blocks?? That drive is /not/ a 4k sector drive.
> Here's what the kernel said when I plugged in the other ("Plugable" brand) UAS
> bridge[1]:
>
> [ 32.466870] usb 2-4: new SuperSpeed USB device number 2 using xhci_hcd
> [ 32.498996] usbcore: registered new interface driver usb-storage
> [ 37.660963] scsi host6: uas
> [ 37.661193] usbcore: registered new interface driver uas
> [ 37.661292] queue_bulk_sg_tx: num=1 sg=ffff880447764500 addr=45af41000 len=0 pagelink=ffffea00116bd042
> [ 37.661550] queue_bulk_sg_tx: num=1 sg=ffff8804483fb600 addr=45af41000 len=0 pagelink=ffffea00116bd042
> [ 37.661744] scsi 6:0:0:0: Direct-Access Plugable USB3-SATA-UASP1 0 PQ: 0 ANSI: 6
> [ 37.661865] queue_bulk_sg_tx: num=1 sg=ffff8804483fba00 addr=45af41000 len=0 pagelink=ffffea00116bd042
> [ 37.662053] queue_bulk_sg_tx: num=1 sg=ffff8804483fba00 addr=45af41000 len=0 pagelink=ffffea00116bd042
> [ 37.662294] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=45af41000 len=0 pagelink=ffffea00116bd042
> [ 37.662488] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=45b6ab000 len=0 pagelink=ffffea00116daac2
> [ 37.663041] sd 6:0:0:0: Attached scsi generic sg2 type 0
> [ 37.663138] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=44897c000 len=0 pagelink=ffffea0011225f02
> [ 37.664420] sd 6:0:0:0: [sdc] 312581808 512-byte logical blocks: (160 GB/149 GiB)
> [ 37.664599] queue_bulk_sg_tx: num=1 sg=ffff880447764400 addr=45b5c0000 len=0 pagelink=ffffea00116d7002
> [ 37.664833] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=45b5c0000 len=0 pagelink=ffffea00116d7002
> [ 37.665022] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=45b5c0000 len=0 pagelink=ffffea00116d7002
> [ 37.665255] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=45b5c0000 len=0 pagelink=ffffea00116d7002
> [ 37.665421] sd 6:0:0:0: [sdc] Write Protect is off
> [ 37.665532] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0a00 addr=45b5c0000 len=0 pagelink=ffffea00116d7002
> [ 37.665735] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0a00 addr=45b5c0000 len=0 pagelink=ffffea00116d7002
> [ 37.665877] sd 6:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
> [ 37.666003] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1700 addr=4587a8e00 len=0 pagelink=ffffea001161ea02
> [ 37.666293] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1700 addr=45b5c0000 len=0 pagelink=ffffea00116d7002
> [ 37.670190] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1600 addr=44897c000 len=0 pagelink=ffffea0011225f02
> [ 37.676364] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=457692000 len=0 pagelink=ffffea00115da482
> [ 37.681800] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=457692000 len=0 pagelink=ffffea00115da482
> [ 37.687125] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=457692000 len=0 pagelink=ffffea00115da482
> [ 37.692335] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=457692000 len=0 pagelink=ffffea00115da482
> [ 37.697451] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=457692000 len=0 pagelink=ffffea00115da482
> [ 37.702429] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=457692000 len=0 pagelink=ffffea00115da482
> [ 37.707312] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=457692000 len=0 pagelink=ffffea00115da482
> [ 37.712109] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=448b56000 len=0 pagelink=ffffea001122d582
> [ 38.077805] queue_bulk_sg_tx: num=1 sg=ffff8800371f2900 addr=45b55c000 len=0 pagelink=ffffea00116d5702
> [ 38.084416] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0e00 addr=45ac31000 len=0 pagelink=ffffea00116b0c42
> [ 38.091107] queue_bulk_sg_tx: num=1 sg=ffff880456804800 addr=45b1d8000 len=0 pagelink=ffffea00116c7602
> [ 38.097794] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=4577f0000 len=0 pagelink=ffffea00115dfc02
> [ 38.104336] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=457a58000 len=0 pagelink=ffffea00115e9602
> [ 38.134057] queue_bulk_sg_tx: num=1 sg=ffff88045b9e1200 addr=44727b000 len=0 pagelink=ffffea00111c9ec2
> [ 38.140514] queue_bulk_sg_tx: num=1 sg=ffff880456804f00 addr=4574d6000 len=0 pagelink=ffffea00115d3582
> [ 38.146793] queue_bulk_sg_tx: num=1 sg=ffff88045b9e0900 addr=45c49a000 len=0 pagelink=ffffea0011712682
> [ 38.153256] queue_bulk_sg_tx: num=1 sg=ffff880456805200 addr=4475f4000 len=0 pagelink=ffffea00111d7d02
> [ 38.156858] sdc: sdc1 sdc2 sdc3
> [ 38.162992] queue_bulk_sg_tx: num=1 sg=ffff880447765100 addr=4482a2000 len=0 pagelink=ffffea001120a882
> [ 38.168410] queue_bulk_sg_tx: num=1 sg=ffff88008ab87400 addr=45ac2d000 len=0 pagelink=ffffea00116b0b42
>
> (Sorry for the noise, this really is the last email for tonight.)
>
> --D
>
> [1] lsusb output: http://djwong.org/docs/plugable.txt
>
> > [ 252.171739] queue_bulk_sg_tx: num=4294967295 sg=ffff8804584e0b00 addr= (null) len=0 pagelink=116b8882
> > [ 252.173706] queue_bulk_sg_tx: num=4294967295 sg= (null), ABORT
> > <KABOOM>
> >
> > I wrote in a printk to spit out num_sgs and some of the sg data right before
> > the sg_next() call. Looks like num_sgs is originally zero? I then patched
> > the code to break early if num_sgs == 0:
> >
> > /* Calculate length for next transfer --
> > * Are we done queueing all the TRBs for this sg entry?
> > */
> > this_sg_len -= trb_buff_len;
> > printk(KERN_ERR "%s: num=%u sg=%p addr=%lx len=%u pagelink=%lx\n", __func__, num_sgs, sg, addr, this_sg_len, sg->page_link);
> > if (this_sg_len == 0) {
> > if (num_sgs == 0) {
> > printk(KERN_ERR "%s: breaking early, no sgs??\n", __func__);
> > break;
> > }
> > --num_sgs;
> > if (num_sgs == 0)
> > break;
> > sg = sg_next(sg);
> > addr = (u64) sg_dma_address(sg);
> > this_sg_len = sg_dma_len(sg);
> >
> > This produced this log[1] which I've excerpted here:
> >
> > [ 96.944791] usb 2-4: new SuperSpeed USB device number 2 using xhci_hcd
> > [ 96.972881] usbcore: registered new interface driver usb-storage
> > [ 128.315902] scsi host6: uas
> > [ 128.318605] usbcore: registered new interface driver uas
> > [ 128.318691] queue_bulk_sg_tx: num=1 sg=ffff88044650ed00 addr=446958000 len=0 pagelink=ffffea00111a5602
> > [ 128.318960] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=446958000 len=0 pagelink=ffffea00111a5602
> > [ 128.321144] scsi 6:0:0:0: Direct-Access Apricorn 0128 PQ: 0 ANSI: 6
> > [ 128.321165] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=45cbb1000 len=0 pagelink=ffffea001172ec42
> > [ 128.323714] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=447738000 len=0 pagelink=ffffea00111dce02
> > [ 128.326233] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=45a4c8000 len=0 pagelink=ffffea0011693202
> > [ 128.329157] sd 6:0:0:0: Attached scsi generic sg2 type 0
> > [ 128.331328] queue_bulk_sg_tx: num=1 sg=ffff88045795ce00 addr=456ad7000 len=0 pagelink=ffffea00115ab5c2
> > [ 128.331428] sd 6:0:0:0: [sdc] 312581808 512-byte logical blocks: (160 GB/149 GiB)
> > [ 128.331431] sd 6:0:0:0: [sdc] 4096-byte physical blocks
> > [ 128.331448] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=456ad7000 len=0 pagelink=ffffea00115ab5c2
> > [ 128.333772] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=44649e000 len=0 pagelink=ffffea0011192782
> > [ 128.336191] queue_bulk_sg_tx: num=1 sg=ffff880457a02700 addr=45683b000 len=0 pagelink=ffffea00115a0ec2
> > [ 128.338561] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=37355000 len=0 pagelink=ffffea0000dcd542
> > [ 128.340979] queue_bulk_sg_tx: num=1 sg=ffff880457a02c00 addr=8a8e3000 len=0 pagelink=ffffea00022a38c2
> > [ 128.343246] sd 6:0:0:0: [sdc] Write Protect is off
> > [ 128.343263] queue_bulk_sg_tx: num=1 sg=ffff880457a02400 addr=8a8e2000 len=0 pagelink=ffffea00022a3882
> > [ 128.345461] sd 6:0:0:0: [sdc] No Caching mode page found
> > [ 128.345463] sd 6:0:0:0: [sdc] Assuming drive cache: write through
> > [ 128.345475] queue_bulk_sg_tx: num=1 sg=ffff880457a02000 addr=45ba6ba00 len=0 pagelink=ffffea00116e9ac2
> > [ 128.347752] queue_bulk_sg_tx: num=1 sg=ffff880457a02000 addr=8ab21000 len=0 pagelink=ffffea00022ac842
> > [ 128.352127] queue_bulk_sg_tx: num=1 sg=ffff880457a02c00 addr=8637f000 len=0 pagelink=ffffea000218dfc2
> > [ 128.354225] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=8637e000 len=0 pagelink=ffffea000218df82
> > [ 128.356278] queue_bulk_sg_tx: num=1 sg=ffff880457a02700 addr=8a8b7000 len=0 pagelink=ffffea00022a2dc2
> > [ 128.358325] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=8a8b6000 len=0 pagelink=ffffea00022a2d82
> > [ 128.360450] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=8a8b1000 len=0 pagelink=ffffea00022a2c42
> > [ 128.362443] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=8a8b0000 len=0 pagelink=ffffea00022a2c02
> > [ 128.364448] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=84d55000 len=0 pagelink=ffffea0002135542
> > [ 128.366488] queue_bulk_sg_tx: num=1 sg=ffff880457a02700 addr=84d54000 len=0 pagelink=ffffea0002135502
> > [ 128.368545] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=863bd000 len=0 pagelink=ffffea000218ef42
> > [ 128.732280] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=37182000 len=0 pagelink=ffffea0000dc6082
> > [ 128.734945] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=3718200d len=499 pagelink=ffffea0000dc6082
> > [ 128.737631] queue_bulk_sg_tx: num=0 sg=ffff880457a02600 addr=0 len=0 pagelink=ffffea0000dc6082
> > [ 128.740150] queue_bulk_sg_tx: breaking early, no sgs??
> > [ 128.742665] usb 2-4: check_trb_math - ep 0x8b - Miscalculated number of TRBs, -1 left
> > [ 159.618522] sd 6:0:0:0: [sdc] uas_eh_abort_handler 0 tag 1 inflight: IN
> > [ 159.620287] sd 6:0:0:0: [sdc] CDB:
> > [ 159.622016] Read(10): 28 00 00 00 00 0f 00 00 00 00
> > [ 159.624014] scsi host6: uas_eh_bus_reset_handler start
> > [ 159.728110] usb 2-4: reset SuperSpeed USB device number 2 using xhci_hcd
> >
> > In the full log, you can at time 192.488278 that we got all jammed up in the sd
> > probe trying to read a disklabel off the drive. I'm suspicious of those last
> > two queue_bulk_sg_tx printks since it seems awfully coincidental that it gets
> > called twice, once with a sane looking addr and length, then again with the
> > same sg and page_link yet the addr and num_sgs have become zero.
> >
> > (Ok, now I'm really going to bed.)
> >
> > --D
> >
> > [1] http://djwong.org/docs/bad2.txt
> > >
> > > --D
> > >
> > > >
> > > > Note that the device will likely still not work, but it should no
> > > > longer crash things. When running 3.18 please collect the output of
> > > > "dmesg" after plugging in the drive and send that to me, then we'll see
> > > > if we can get it to work from there.
> > > >
> > > > Regards,
> > > >
> > > > Hans
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