From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 854DE19D07B; Mon, 26 Aug 2024 22:48:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724712496; cv=none; b=CqtauFbdZu9O0X254n7oEDpW/u5ZuLWYFFcsLnKUrLxmMkaYGiz9H4e6v2DWgiHp6bHIcXY7kihssw9+BtlDTHokFqocGXv4U4Q8VFw9lJ/t1xpAUsJ56ocnrlTW3mGTbFisKRzs2JU9G98L8Ev/7MMGDLbvf3/51Tcz42RzaBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724712496; c=relaxed/simple; bh=x1hjh95k0wxaveZBrA+vEUT6erVcu1eYnkXU9yxB4Gg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=a80/yYixh3ljkYYDzSvXzFYR7JdbOscsV/VPJNCERJvOrFKF/o60L/38RdqWDy4Xjd7V5aUKrQOM3dYDvzRp40dvY+42raCe8QqUb5AOd5CbL+D7VSweyGUqaNJC84P1Yy2dMsPTBkjbGq4sDh8aRH56AJ21UvULFb5+fq3HSLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=ff7TDC5i; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ff7TDC5i" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724712495; x=1756248495; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=x1hjh95k0wxaveZBrA+vEUT6erVcu1eYnkXU9yxB4Gg=; b=ff7TDC5iyKLf0y19udb2Y01IPpcUrF4ZvFHWMBO39tywc+FHhB6vFqIn ZrQUp7SjfOcJ4cHF9Xvr8SO5sHaW6+3+a1RWSQAKQcO3pQkwXBX2OyG17 UMd6lApXrQ8ReGLPPCDKAxBUtpgdcckary88YHcC+sa3HXj3Py9MlV49q BR9BDiIQWEtSx3guCT3TMvs1akL4JGMiqg8TSQ9UZg0tPj6eaYCu3J5r/ rVsCLwlE2QvgTvVUvcvGlkBX6Jyr8OAxzrQZh8AjxnUtUAG14LaVYB9p7 eIknopSEd9DKnm7aQ8/xWzZzgtYfV/uPIZtwjyKOtqiohuANn8wsBioo9 w==; X-CSE-ConnectionGUID: FIUFE4RUTQusfzdwh9JIfQ== X-CSE-MsgGUID: k0YRAnUYTKetC9C9LTHtvQ== X-IronPort-AV: E=McAfee;i="6700,10204,11176"; a="13225200" X-IronPort-AV: E=Sophos;i="6.10,178,1719903600"; d="scan'208";a="13225200" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2024 15:48:14 -0700 X-CSE-ConnectionGUID: OlW0FGS6T1Sc4Z+Gg1PEvw== X-CSE-MsgGUID: kAJuRAjTQquHVlYP0FTDJg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,178,1719903600"; d="scan'208";a="62972252" Received: from mesiment-mobl2.amr.corp.intel.com (HELO vcostago-mobl3) ([10.124.223.39]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Aug 2024 15:48:11 -0700 From: Vinicius Costa Gomes To: Miklos Szeredi Cc: brauner@kernel.org, amir73il@gmail.com, hu1.chen@intel.com, malini.bhandaru@intel.com, tim.c.chen@intel.com, mikko.ylinen@intel.com, lizhen.you@intel.com, linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 04/16] overlayfs: Document critical override_creds() operations In-Reply-To: References: <20240822012523.141846-1-vinicius.gomes@intel.com> <20240822012523.141846-5-vinicius.gomes@intel.com> Date: Mon, 26 Aug 2024 15:48:07 -0700 Message-ID: <87wmk2lx3s.fsf@intel.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Miklos Szeredi writes: > On Thu, 22 Aug 2024 at 03:25, Vinicius Costa Gomes > wrote: >> >> Add a comment to these operations that cannot use the _light version >> of override_creds()/revert_creds(), because during the critical >> section the struct cred .usage counter might be modified. > > Why is it a problem if the usage counter is modified? Why is the > counter modified in each of these cases? > Working on getting some logs from the crash that I get when I convert the remaining cases to use the _light() functions. Perhaps I was wrong on my interpretation of the crash. Thanks for raising this, I should have added more information about this. Cheers, -- Vinicius