On Wed, 16 Jan 2019, Linus Torvalds wrote: > > "Being owner or has cap" (whichever cap) is probably OK. On the other > > hand, writeability check makes more sense in general - could we > > somehow check if the user has write access to the file instead of > > checking if it currently is opened read-write? > > That's likely the best option. We could say "is it open for write, or > _could_ we open it for writing?" > > It's a slightly annoying special case, and I'd have preferred to avoid > it, but it doesn't sound *compilcated*. > > I'm on the road, but I did send out this: > > https://lore.kernel.org/lkml/CAHk-=wif_9nvNHJiyxHzJ80_WUb0P7CXNBvXkjZz-r1u0ozp7g@xxxxxxxxxxxxxx/ > > originally. The "let's try to only do the mmap residency" was the > optimistic "maybe we can just get rid of this complexity entirely" > version.. > > Anybody willing to test the above patch instead? And replace the > > || capable(CAP_SYS_ADMIN) > > check with something like > > || inode_permission(inode, MAY_WRITE) == 0 > > instead? > > (This is obviously after you've reverted the "only check mmap > residency" patch..) So that seems to deal with mincore() in a reasonable way indeed. It doesn't unfortunately really solve the preadv2(RWF_NOWAIT), nor does it provide any good answer what to do about it, does it? Thanks, -- Jiri Kosina SUSE Labs
