On Thu, 3 Jun 2010, Nick Piggin wrote: > You'll have to be careful, truncate will pass other things down like > mode to get rid of suid. Oh, right. > If you just wanted to ignore mtime changes on truncate, then masking > it off would be the way to go I think. > > if (valid & ATTR_SIZE) > valid &= ~ATTR_SIZE; > > Would you also want to do the same thing with suid kill bits from > truncate, then? Mask off ATTR_MODE and just read it back from the > server too? That would be logical, but no, it didn't used to do that, and now it can't start doing it for fear of creating a security hole. Also suid removal happens very rarely compared to mtime update, so a rare additional chmod request (which might be superfluous for some filesystems) in addition to write and truncate is I think acceptable. (In fact I think it would be cleanest if truncate/ftruncate was a separate operation from setattr on all levels, but that's a different story.) So for now something like if (valid & ATTR_SIZE) valid &= ~(ATTR_MTIME | ATTR_CTIME); would work? Thanks, Miklos -- 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
