git-fetch does not work from .git subdirectory

I was under the impression that git commands which affect repository (as opposed to the local file system) work from any subdirectory inside the repository. For example:

[b04825@efes linux.cq-test]$ git log -1
commit f35d179fde24be5e1675b1df9f7a49b8d95561b2
Author: Timur Tabi <timur@freescale.com>
Date:   Wed Oct 31 15:56:20 2012 +0200
...
[b04825@efes linux.cq-test]$ cd .git
[b04825@efes .git]$ git log -1
commit f35d179fde24be5e1675b1df9f7a49b8d95561b2
Author: Timur Tabi <timur@freescale.com>
Date:   Wed Oct 31 15:56:20 2012 +0200
...

It appears, however, that git-fetch does not work this way:

[b04825@efes linux.cq-test]$ git fetch upstream master
From ../linux-2.6
 * branch            master     -> FETCH_HEAD
[b04825@efes linux.cq-test]$ cd .git
[b04825@efes .git]$ git fetch upstream master
fatal: '../linux-2.6.git' does not appear to be a git repository
fatal: The remote end hung up unexpectedly

This makes it complicated because git hooks run from the .git directory on normal repositories, but they run from the top-level directory on bare repositories. Apparently, you need to be in the top-level directory for git-fetch to run in any kind of repository.