[lkml]   [2011]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC] st_nlink after rmdir() and rename()
Linus Torvalds <> writes:

> On Thu, Mar 3, 2011 at 12:46 PM, OGAWA Hirofumi
> <> wrote:
>> But, some commands see i_nlink (IIRC, it's checking i_nlink == 2, to
>> know empty dir or not).
> Actually, that would be a serious bug in the application.
> The traditional rule of thumb is that a directory with i_nlink==1 has
> a "I'm not counting at all".
> For example, I think that's the rule that 'find' uses to decide if a
> directory can have subdirectories (and when it could try to stop
> scanning early): i_nlink == 1 means that yes, it _can_ have
> subdirectories, we just don't know how many.

Yes. I think it is.

> So checking i_nlink==2 is actually a user-level bug.

We can call it's the user-level bug, but like you know, we will receive
many complain if old behavior was broken. If you are saying i_nlink == 2
is meaning the undefine, it sounds strange. (I was thinking it's why
isofs is using i_nlink == 1 always. I.e. i_nlink >= 2 is defined
behavior. Actually the reason would be "find" was checking i_nlink == 2

>> So we have to simulate some levels. I guess you
>> are not saying we don't need to care it at all though.
> I'm saying that it should just work to set i_nlink=1 and not do
> anything at all. Ever. It's a valid model for directory counts.
> Seriously - that's what isofs does, for example. It does mean that
> 'find' for certain cases gets bit more expensive, but on the other
> hand, other operations are a lot _less_ expensive.
> We might well try that as a FAT mount option, to let people decide
> whether they really do want the "scan directories all the time" or
> only the "let 'find' scan directories when it needs to" behavior.

Yes. i_nlink == 1 is ok, IIRC (I checked last time at least. And I used
i_nlink == 1 for exFAT). And I agree with you almost all, but isofs is
read-only, the read-only is why I was not really sure.

And I can't only see is why you refuse to make consistent behavior (if
you are saying it). It's why I said if it's _really easy_.

OGAWA Hirofumi <>

 \ /
  Last update: 2011-03-03 22:39    [W:0.074 / U:0.060 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site