Re: FS: hardlinks on directories

Jeff Muizelaar
2003-08-04T15:31:46Z

Stephan von Krawczynski wrote:

>
>I guess this is not really an option if talking about hundreds or thousands of
>"links", is it?
>
>
actually hundreds or thounds still should be ok. See...

>From: Alexander Viro <http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&safe=off&q=author:viro%40math.psu.edu+> (viro@math.psu.edu <mailto:viro%40math.psu.edu>)
>Subject: Re: hundreds of mount --bind mountpoints?
>
>On Sun, 22 Apr 2001, David L. Parsley wrote:
>> Hi,
>>
>> I'm still working on a packaging system for diskless (quasi-embedded)
>> devices. The root filesystem is all tmpfs, and I attach packages inside
>> it. Since symlinks in a tmpfs filesystem cost 4k each (ouch!), I'm
>> considering using mount --bind for everything. This appears to use very
>> little memory, but I'm wondering if I'll run into problems when I start
>> having many hundreds of bind mountings. Any feel for this?
>
>Memory use is sizeof(struct vfsmount) per binding. In principle, you can get
>in trouble when size of /proc/mount will get past 4Kb - you'll get only
>first 4 (actually 3, IIRC) kilobytes, so stuff that relies on the contents
>of said file may get unhappy. It's fixable, though.
>
>
>
The 4Kb problem has also been solved in 2.6, I just tested having
about 5k mounts and things seemed fine. /proc/mounts reports all
of them.

-Jeff