----- Original Message ----- > From: "Eyal Ben David" <bdeyal@xxxxxxxxx> > To: "Johannes Thumshirn" <jthumshirn@xxxxxxx> > Cc: "Ewan D. Milne" <emilne@xxxxxxxxxx>, dgilbert@xxxxxxxxxxxx, "Laurence Oberman" <loberman@xxxxxxxxxx>, > linux-scsi@xxxxxxxxxxxxxxx > Sent: Tuesday, November 22, 2016 8:48:06 AM > Subject: Re: SG does not ignore dxferp (direct io + mmap) > > Same problem on Fedora 23 > > $ uname -r > 4.7.10-100.fc23.x86_64 > > $ sudo ./sg_mmap_read -d /dev/sg0 -l 0 | od -t x1 > 0000000 eb 63 90 10 8e d0 bc 00 b0 b8 00 00 8e d8 8e c0 > ... > > $ sudo ./sg_mmap_read -d /dev/sg0 -l 0 -m | od -t x1 > 0000000 eb 63 90 10 8e d0 bc 00 b0 b8 00 00 8e d8 8e c0 > ... > > $ sudo ./sg_mmap_read -d /dev/sg0 -l 0 -m -b | od -t x1 > 0000000 00 63 90 10 8e d0 bc 00 b0 b8 00 00 8e d8 8e c0 > ... > > 2016-11-22 10:37 GMT+02:00 Johannes Thumshirn <jthumshirn@xxxxxxx>: > > On Mon, Nov 21, 2016 at 01:24:02PM -0500, Ewan Milne wrote: > >> On Mon, 2016-11-21 at 12:34 -0500, Douglas Gilbert wrote: > >> > There was also this change which seems closer to the problem area: > >> > > >> > commit 461c7fa126794157484dca48e88effa4963e3af3 > >> > Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > >> > Date: Tue Feb 2 16:57:35 2016 -0800 > >> > > >> > drivers/scsi/sg.c: mark VMA as VM_IO to prevent migration > >> > ... > >> > > >> > diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c > >> > index 503ab8b..5e82067 100644 > >> > --- a/drivers/scsi/sg.c > >> > +++ b/drivers/scsi/sg.c > >> > @@ -1261,7 +1261,7 @@ sg_mmap(struct file *filp, struct vm_area_struct > >> > *vma) > >> > } > >> > > >> > sfp->mmap_called = 1; > >> > - vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; > >> > + vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; > >> > vma->vm_private_data = sfp; > >> > vma->vm_ops = &sg_mmap_vm_ops; > >> > return 0; > >> > > >> > Doug Gilbert > >> > > >> > >> Neither this change nor "sg: fix dxferp in from_to case" appears to > >> fix the issue when applied on top of 4.4. Still looking... > > > > This brings bad memories from commit 2d99b55d3 back to live, but this is > > applied on all test kernels I have. > > > > I too will run some bisection as well now that we have an easy reproducer > > and > > my timezone is somewhat ahead. Let's see if we can stretch the workday a > > bit. > > > > Byte, > > Johannes > > > > -- > > Johannes Thumshirn Storage > > jthumshirn@xxxxxxx +49 911 74053 689 > > SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg > > GF: Felix Imendörffer, Jane Smithard, Graham Norton > > HRB 21284 (AG Nürnberg) > > Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850 > -- > 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 > Its not failing on 4.8-rc2 so working on tracing rgw ioctl SG_DXFER_FROM_DEV as well and will bisect this weekend and/or add some kernel probes. Just need to get some time. Johannes or Ewan may beat me to it. Working RHEL7 open("/dev/sg1", O_RDWR) = 3 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x7f5645d4a000 ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[16]=[88, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 01, 00, 00], mx_sb_len=96, iovec_count=0, dxfer_len=512, timeout=30000, flags=0x4, data[512]=[0x7f5645d4a000], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0 write(1, 0x7f5645d4a000, 640000000 63eb 1090 d08e 00bc b8b0 0000 d88e c08e ) = 64 0000010 befb 7c00 00bf b906 0200 a4f3 21ea 0006 0000020 be00 07be 0438 0b75 c683 8110 fefe 7507 0000030 ebf3 b416 b002 bb01 7c00 80b2 748a 8b01 munmap(0x7f5645d4a000, 8192) = 0 close(3) = 0 exit_group(0) = ? +++ exited with 0 +++ 0000040 Failing 4.4 open("/dev/sg1", O_RDWR) = 3 mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x7f2951de3000 ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[16]=[88, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 01, 00, 00], mx_sb_len=96, iovec_count=0, dxfer_len=512, timeout=30000, flags=0x4, data[512]=[0x7f2951de3000], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=0, info=0}) = 0 write(1, 0x7f2951de3000, 64) = 64 munmap(0x7f2951de3000, 81920000000 6300 1090 d08e 00bc b8b0 0000 d88e c08e 0000010 befb 7c00 00bf b906 0200 a4f3 21ea 0006 ) = 0 0000020 be00 07be 0438 0b75 c683 8110 fefe 7507 0000030 ebf3 b416 b002 bb01 7c00 80b2 748a 8b01 close(3) = 0 exit_group(0) = ? +++ exited with 0 +++ 0000040 -- 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
