On Thu, 2014-05-22 at 10:49 +0000, KY Srinivasan wrote: > > > > -----Original Message----- > > From: Andy Whitcroft [mailto:apw@xxxxxxxxxxxxx] > > Sent: Wednesday, May 21, 2014 7:25 AM > > To: Ian Abbott > > Cc: linux-scsi@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; KY Srinivasan; > > Haiyang Zhang; James E.J. Bottomley; Tim Gardner > > Subject: Re: [PATCH 0/2] scsi: hyper-v storvsc changes by Ubuntu > > > > On 16 May 2014 16:39, Ian Abbott <abbotti@xxxxxxxxx> wrote: > > > These changes to the Microsoft Hyper-V storage driver in Ubuntu > > > Saucy's > > > 3.13 kernel look useful for the mainline kernel, especially as they > > > enable 'TRIM' support. > > > > > > Andy Whitcroft (2): > > > scsi: hyper-v storvsc switch up to SPC-3 > > > scsi: hyper-v storvsc -- host takes MAINTENANCE_IN commands badly -- > > > elide them > > > > > > drivers/scsi/storvsc_drv.c | 10 ++++++++++ > > > 1 file changed, 10 insertions(+) > > > > > > The back story here is a little complex. The main issue is that the Hyper-V > > drives claim to be SPC-2, and yet implement the SPC-3 extensions for TRIM. > > We did attempt to upstream quirks to allow these features to be negotiated > > specifically for the Hyper-V virtual drives (minimum regression potential) but > > these were NAKd, and it was suggested that just overriding the Hyper-V > > drives to SPC-3 unconditionally was more appropriate. The first of the > > patches here does does this. This has been sitting in our tree for some time > > as it was not clear that this would be entirely safe, though the SPC-3 bits are > > in theory at least mostly detected. That said this change has been in Ubuntu > > for a full cycle now and does not seem to have caused any issues. If KY is > > happy we should likely submit it formally. The second fix I believed was > > already being submitted to mainline. > > > > KY? > > The Windows guys are not currently comfortable claiming conformance to > SPC-3, as they have not done > the necessary testing. This will change hopefully soon. Any bounds on the value of "soon" are we talking weeks or months? I think trim is a feature, which means no huge rush to get this in, but it is nice to respond in a timely fashion to a request from a distribution to enable a useful feature. James -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
