Messages in this thread | | | From | Damien Le Moal <> | Subject | Re: 5.2.x kernel: WD 8TB USB Drives: Unaligned partial completion (resid=78, sector_sz=512) | Date | Tue, 13 Aug 2019 03:47:09 +0000 |
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On 2019/08/12 19:12, Martin K. Petersen wrote: > > Justin, > >>> Attached 2 x brand new Western Digital 8TB USB 3.0 drives awhile back >>> and ran some file copy tests and was getting these warnings-- is >>> there any way to avoid these warnings? I did confirm with parted >>> that the partition was aligned but this appears to be something >>> related to the firmware on the device according to [1] and [2]? > >> sg_vpd_bdc.txt >> Block device characteristics VPD page (SBC): >> Nominal rotation rate: 5400 rpm >> Product type: Not specified >> WABEREQ=0 >> WACEREQ=0 >> Nominal form factor: 3.5 inch >> ZONED=0 > > Damien: What can we do to limit the messages in cases like this? Would > it make sense to make the residual warning conditional on sd_is_zoned()? >
These WD drives are regular disks, not SMR. Making the warning conditional on sd_is_zoned() will not reduce the amount of messages. REPORT ZONES is the only command that could result in a resid not being aligned to the block size since by definition the command reply is composed of 64B zone descriptors. But that command is now processed through a device method and is not a REQ_OP_XXX anymore, so as an internal req, it does not go through sd_done() for completion right ? All other zone commands either have no buffer, or the exact same requirement as regular disks, expecting a block aligned resid. So I think that using sd_is_zoned() is not relevant to this problem.
Bottom line: this USB adapter is weird and likely triggers all the unaligned resid. I do get regularly reports of similar problem with SAS HBAs, all always fixed with HBA FW updates. Not sure if there is a FW available for these drives. I will ask internally.
In the mean time, rate limiting or removing the sd_printk() call may be the only option. Failing all commands with an invalid resid would be safer I guess, but will at best likely cause a lot of retry on these buggy devices, and break the drive operation/perfomance completely in the worst case.
Or the usb mass storage device driver could add some silent forced resid alignment too.
Best regards.
-- Damien Le Moal Western Digital Research
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