On Tue, Jun 01, 2010 at 10:04:13AM -0700, Linus Torvalds wrote: > > > On Wed, 2 Jun 2010, Nick Piggin wrote: > > > > It appears like the time_attrs parameter of security_path_truncate is > > unused by any security module, so I wonder if we can remove it? > > I think we should aggressively remove interfaces that aren't used. The VFS > side has been complicated several times because of the security hooks, and > if they ended up not getting used and just complicates logic, we should > remove it. OK, good. I'll put a patch at the head of my queue. > > We cannot really get it right for truncate(2) calls anyway without > > holding i_mutex over the call (because ATTR_MTIME|ATTR_CTIME is > > effectively set iff size changes). So the meaning of this parameter > > today is misleading anyway. > > Why do we pass it in to do_truncate() at all, btw? Especially as we seem > to be a bit confused about it. A regular 'truncate()' passes in a > time_attrs of '0', while a 'ftruncate()' passes ATTR_MTIME|ATTR_CTIME. Yes, and then it relies on the filesystems to update MTIME and CTIME if size has changed. Many get it wrong (and in my confusion I also just broke a couple more). So I'm working on fixing it for everyone. http://marc.info/?l=linux-fsdevel&m=127539956932537&w=2 > That doesn't sound right. And if it is (because I can well imagine some > strange and subtle POSIX rule wrt ftruncate() and mtime/ctime), I think we > should add a comment on it, since I've clearly forgotten the reason. Yeah a comment would have really helped, since it seems stupid it must be a typo in the standards document. 6e656be899993f450a765056cdc8d87e58906508 > Btw, right now we pass in ATTR_OPEN too to the security_path_truncate() > call. Which again doesn't seem to be _used_ by any security thing, and > which also violates the naming of that argument. So there's some > additional strangeness going on there. > > (That ATTR_OPEN case was introduced in commit be6d3e56a6 ("introduce new > LSM hooks where vfsmount is available"), for what its worth. The ATTR_OPEN > bit seems to have been copied from the do_truncate() call below it, I > think it's just a copy-paste error). Good point. That'll get nuked when we remove the parameter. -- 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
