From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: silent semantic changes with reiser4 Date: Thu, 26 Aug 2004 20:40:46 +0100 Message-ID: <20040826194046.GX5733@mail.shareable.org> References: <20040826124119.GA431@lst.de> <20040826134812.GB5733@mail.shareable.org> <20040826155744.GA4250@lst.de> <20040826160638.GJ5733@mail.shareable.org> <20040826161303.GA4716@lst.de> <20040826172029.GP5733@mail.shareable.org> <20040826181620.GT5733@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Hans Reiser , Alex Zarochentsev , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Lyamin aka FLX , ReiserFS List Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com To: Linus Torvalds Content-Disposition: inline In-Reply-To: List-Id: linux-fsdevel.vger.kernel.org Linus Torvalds wrote: > > It is not the kernel which decides. The filesystem containing > > /dev/hda/part1 opens "the directory branch". > > But that filesystem cannot know what the _other_ filesystem configurations > are. And that's what you'd have to have to mount. At which point, userspace comes in. Who knows what userspace chooses. > > The obvious implementation has the userspace helper just mounting it, > > end of story. If the mount command fails, it fails. Much like autofs. > > Yes, that would work, but it's of questionable use. If you want autofs, > then just _use_ autofs. I don't mean to imply it's useful behaviour: only that it seems to happen by default if you don't do anything special to prevent it, if you see what I mean. It does seem useful to have _files_ mounted automagically (using loopback devices): for example, cd into a .iso file and it would be nice to see the contents. At this point, deciding on the preferred -EBUSY or not behaviour becomes relevant, as does deciding whether the .iso in this example is viewed using the kernel's isofs code, or using a userspace helper in the same way as we'd use one to browse a .zip file. -- Jamie