git push issue

mbnoimi@mbnoimi-pc ~/Desktop/p3 $ git clone '/home/mbnoimi/Desktop/p1'
Cloning into 'p1'...
done.
Checking connectivity... done
mbnoimi@mbnoimi-pc ~/Desktop/p3 $ cd p1/
mbnoimi@mbnoimi-pc ~/Desktop/p3/p1 $ git commit -a -m 'add new line'[master f71dcc1] add new line
 1 file changed, 1 insertion(+)
mbnoimi@mbnoimi-pc ~/Desktop/p3/p1 $ git push origin
warning: push.default is unset; its implicit value is changing in
Git 2.0 from 'matching' to 'simple'. To squelch this message
and maintain the current behavior after the default changes, use:

  git config --global push.default matching

To squelch this message and adopt the new behavior now, use:

  git config --global push.default simple

See 'git help config' and search for 'push.default' for further information.
(the 'simple' mode was introduced in Git 1.7.11. Use the similar mode
'current' instead of 'simple' if you sometimes use older versions of Git)

Counting objects: 5, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 269 bytes | 0 bytes/s, done.
Total 3 (delta 1), reused 0 (delta 0)
remote: error: refusing to update checked out branch: refs/heads/master
remote: error: By default, updating the current branch in a non-bare repository
remote: error: is denied, because it will make the index and work tree inconsistent
remote: error: with what you pushed, and will require 'git reset --hard' to match
remote: error: the work tree to HEAD.
remote: error:
remote: error: You can set 'receive.denyCurrentBranch' configuration variable to
remote: error: 'ignore' or 'warn' in the remote repository to allow pushing into
remote: error: its current branch; however, this is not recommended unless you
remote: error: arranged to update its work tree to match what you pushed in some
remote: error: other way.
remote: error:
remote: error: To squelch this message and still keep the default behaviour, set
remote: error: 'receive.denyCurrentBranch' configuration variable to 'refuse'.
To /home/mbnoimi/Desktop/p1
 ! [remote rejected] master -> master (branch is currently checked out)
error: failed to push some refs to '/home/mbnoimi/Desktop/p1'
mbnoimi@mbnoimi-pc ~/Desktop/p3/p1 $