On Thu, Jun 26 2008, Adel Gadllah wrote: > 2008/6/26 Jens Axboe <jens.axboe@xxxxxxxxxx>: > > On Thu, Jun 26 2008, Adel Gadllah wrote: > >> 2008/6/26 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>: > >> > On Fri, 27 Jun 2008 00:08:46 +0900 > >> > FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote: > >> > > >> >> On Thu, 26 Jun 2008 17:05:50 +0200 > >> >> "Adel Gadllah" <adel.gadllah@xxxxxxxxx> wrote: > >> >> > >> >> > 2008/6/26 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>: > >> >> > > On Thu, 26 Jun 2008 12:10:25 +0200 > >> >> > > "Adel Gadllah" <adel.gadllah@xxxxxxxxx> wrote: > >> >> > > > >> >> > >> 2008/6/18 Peter Jones <pjones@xxxxxxxxxx>: > >> >> > >> > Douglas Gilbert wrote: > >> >> > >> >> > >> >> > >> >> Peter Jones wrote: > >> >> > >> >>> > >> >> > >> >>> FUJITA Tomonori wrote: > >> >> > >> >>> > >> >> > >> >>>> Well, this changes sg behaviour since sg's allow_ops filter has a > >> >> > >> >>>> access permission different from blk_verify_command filter's. > >> >> > >> >>> > >> >> > >> >>> > > >> >> > >> >>>> > >> >> > >> >>>> I guess that the first thing you need to do is that figuring out a > >> >> > >> >>>> proper access permission for each command, which sg maintainer, etc > >> >> > >> >>>> can agree. It's pretty hard and that's the reason why this patch has > >> >> > >> >>>> not been merged for years, I think. > >> >> > >> >>> > >> >> > >> >>> I don't think this logic is sound. > >> >> > >> >> > >> >> > >> >> That depends on your viewpoint. > >> >> > >> > > >> >> > >> > My viewpoint is this: > >> >> > >> > > >> >> > >> > 1) Whether you agree with his reasons or not, Linus made it pretty clear > >> >> > >> > that he's against removing the command filter (see > >> >> > >> > http://marc.info/?l=linux-scsi&m=115419945212450&w=2 ) > >> >> > >> > 2) Having different code paths use different filtering code just adds more > >> >> > >> > confusion. > >> >> > >> > 3) If we're going to have filtering, it should be configurable on a > >> >> > >> > per-device basis from userland. > >> >> > >> > > >> >> > >> > Which of these do you disagree with? > >> >> > >> > > >> >> > >> > [...] > >> >> > >> >> > >> >> > >> >> Are per device command filters being proposed? > >> >> > >> > > >> >> > >> > Yes, that's what the patch implements. And it allows the userland to > >> >> > >> > configure them according to the needs of the hardware. > >> >> > >> > >> >> > >> Jens can we add merge this for .27 or does anyone still has objections? > >> >> > > > >> >> > > I think that this patch makes sg's permission stricter. So this could > >> >> > > break the existing user-space applications. > >> >> > > > >> >> > > >> >> > any particular app in mind? > >> >> > >> >> No, but there would be some. > >> >> > >> >> > >> >> > for write access it still allows all commands (because there are some > >> >> > userspace apps tha rely on this). > >> >> > >> >> Yeah, I know. But for read access, some commands will be blocked. > >> > > >> > I think that it's not a good idea to say "this patch could break > >> > something but we have no idea about them. So we can merge this." > >> > > >> > It's better to loosen scsi_ioctl's permissions to match with sg's > >> > permission. > >> > >> agreed. > >> > >> Jens please apply the attached patch on top of the old one. > > > > Thanks, I thought this had already been worked out when I saw the > > previous discussion. Please verify that this patch then no longer causes > > ANY different behaviour than what we already have, that's a prerequisite > > for merging it. > > With this patch all apps that worked with the old scsi_ioctl, bsg and > sg filter should behave exactly the same as without the new filter > infrastructure. (it adds no new restrictions) > The only thing it adds is that it allows READ_CAPACITY, REPORT_LUNS, > SERVICE_ACTION_IN, RECEIVE_DIAGNOSTIC and MAINTENANCE_IN_CMD for bsg > and scsi_ioctl in read only mode. > As this was already allowed using /dev/sg* the commands should be > safe, so no regression added. Alright, I think that is good enough. Thanks. -- Jens Axboe -- 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
