From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2A8A91A08A3 for ; Mon, 11 May 2026 11:03:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778497419; cv=none; b=M4cjVt/DNyTG+5oPrj+PAMpXSMssyDIhNv4Erkt2l79U4FMyQSkNeiIA9iJDaMWr2J2/ITf3uzY8KioMgYWB90I3UOy29A4Kf8GyAkls1z+BsJbzhbq5AKyd1zzNqbcqMtQIKW81InizMCEFyTywAv5gBhcCtr11wY6xUFPs4p0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778497419; c=relaxed/simple; bh=TSs/vN70p0uwNlsWNWNw+qqsmsV+31QSlkIJ+FyA3Sk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=V3ZUjWWiAtJa06FPxqRnykTEZpKDSvkYyJ8L1yvBEmgmK3rZItgsfAfHigZlCumkp9SvquazbIM3cgerx/YHHkHKWF5bsxXfSW+EzNIPG7HRZxYZInTl/efICYl2HuiwF0KxS6iZn1ZNSIlSofp0WMpUtONsycO1nO6UjlxxjQI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aJNb3rG9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aJNb3rG9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D9F3C2BCC9; Mon, 11 May 2026 11:03:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778497418; bh=TSs/vN70p0uwNlsWNWNw+qqsmsV+31QSlkIJ+FyA3Sk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=aJNb3rG9eLyETc+c7dCYcxs8r8eBXcRmz0vVg8vuKZW2GoHqqFbVgBbrVrjq9Dysp WTN60mY3CklTkxWRllzkM7NyNddnqX0/Gbk76qbzyp8wTw6rWxy+W9pGwrqyNJQ7Jg tCYkIkvGdY83GQvSDv4miLSw7Aicx8OR2sy0Vo2GQIwntQXfT9n7YyhnZr2ECabXTs ZTyOI7GATKJNiaOtKWAk4JH1C8JvH3iusGCdCP7yPGxxOhaO/c1q0+4hm2DsPJoGGT B/UTvqYPlB1eCwgQ5D7QlRL4dWvxb6jGXRe4b6V7Wwv3UgBlPriRN2fX+5nm4PsXUS mwrDtr4syMDGg== From: Pratyush Yadav To: Pasha Tatashin Cc: rppt@kernel.org, sourabhjain@linux.ibm.com, jbouron@amazon.com, akpm@linux-foundation.org, linux-mm@kvack.org, bhe@redhat.com, linux-kernel@vger.kernel.org, dan.carpenter@linaro.org, rafael.j.wysocki@intel.com, piliu@redhat.com, kexec@lists.infradead.org, pratyush@kernel.org, graf@amazon.com, changyuanl@google.com, mario.limonciello@amd.com Subject: Re: [PATCH v2 3/3] liveupdate: block outgoing session mutations In-Reply-To: <20260506182039.2623553-8-pasha.tatashin@soleen.com> (Pasha Tatashin's message of "Wed, 6 May 2026 14:20:43 -0400") References: <20260506182039.2623553-5-pasha.tatashin@soleen.com> <20260506182039.2623553-8-pasha.tatashin@soleen.com> Date: Mon, 11 May 2026 13:03:34 +0200 Message-ID: <2vxzv7cucint.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Wed, May 06 2026, Pasha Tatashin wrote: > During the reboot() syscall, user processes may still be running > concurrently and attempting to mutate sessions (e.g., adding files or > closing sessions). To prevent this, hold the session header's rwsem and > each session's mutex indefinitely on successful serialization. > > If serialization succeeds, these locks will never be released as the > system transitions to the new kernel, effectively blocking any > concurrent task attempting to modify or release a session. If > liveupdate_reboot() fails, the locks are released in the error path, > allowing normal operation to resume. > > Fixes: 0153094d03df ("liveupdate: luo_session: add sessions support") > Reported-by: Oskar Gerlicz Kowalczuk > Signed-off-by: Pasha Tatashin Reviewed-by: Pratyush Yadav (Google) [...] -- Regards, Pratyush Yadav