On Mon, 8 Oct 2007, Yan Zheng wrote: > > The test for VM_CAN_NONLINEAR always fails Good catch indeed. Though I was puzzled how we do nonlinear at all, until I realized it's "The test for not VM_CAN_NONLINEAR always fails". It's not as serious as it appears, since code further down has been added more recently to simulate nonlinear on non-RAM-backed filesystems, instead of going the real nonlinear way; so most filesystems are now not required to do what VM_CAN_NONLINEAR was put in to ensure they could do. I'm confused as to where that leaves us: is this actually a fix that needs to go into 2.6.23? or will it suddenly disable a system call which has been silently working fine on various filesystems which did not add VM_CAN_NONLINEAR? could we just rip out VM_CAN_NONLINEAR? I hope Nick or Miklos is clearer on what the risks are. (Apologies for all the "not"s and "non"s here, I'm embarrassed after just criticizing Ingo's SCHED_NO_NO_OMIT_FRAME_POINTER!) Hugh > > Signed-off-by: Yan Zheng<yanzheng@xxxxxxxx> > ---- > diff -ur linux-2.6.23-rc9/mm/fremap.c linux/mm/fremap.c > --- linux-2.6.23-rc9/mm/fremap.c 2007-10-07 15:03:33.000000000 +0800 > +++ linux/mm/fremap.c 2007-10-08 19:33:44.000000000 +0800 > @@ -160,7 +160,7 @@ > if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR)) > goto out; > > - if (!vma->vm_flags & VM_CAN_NONLINEAR) > + if (!(vma->vm_flags & VM_CAN_NONLINEAR)) > goto out; > > if (end <= start || start < vma->vm_start || end > vma->vm_end) > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
