From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pb-smtp21.pobox.com (pb-smtp21.pobox.com [173.228.157.53]) (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 E7FC318E77D for ; Wed, 26 Jun 2024 16:17:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=173.228.157.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719418670; cv=none; b=NunN2HoITqzbmvuxOkVID9gNFvYX6m7kpfiEUi3jxyouZuRmnYUcYtA5vBB0dOXYPUul0g/WQD/rNoZ1s94ocZjQiyWoI3wU4MUfphJTNj93my1gLT1D1bDDV0eFjRHob5Uiu8dW2YE2fzxs2lyfhTyHQHS0iAauAaYc3iiekhc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719418670; c=relaxed/simple; bh=0GGmnBM/40yupbkml2QUo/3+25Qasnj+hTooCmTdE1I=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=Koq3hK4hi8/Mglm1pRDm8bv5ALUSXKNy86BtbGYLaH7cjZe4fKMyuDljpDXR4Fi5jLLiczziSwnQhtTP3pS7ENy/hVy/tyyCXCXNBQ3KmL/6GH+LPAQBZt99rU+r24c/RZ7DalhAP7rwjWR2SeASq1xUBDl6D7VdsKF601nd6+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com; spf=pass smtp.mailfrom=pobox.com; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b=NeND6UtR; arc=none smtp.client-ip=173.228.157.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=pobox.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pobox.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=pobox.com header.i=@pobox.com header.b="NeND6UtR" Received: from pb-smtp21.pobox.com (unknown [127.0.0.1]) by pb-smtp21.pobox.com (Postfix) with ESMTP id 745722024A; Wed, 26 Jun 2024 12:17:42 -0400 (EDT) (envelope-from junio@pobox.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=pobox.com; h=from:to:cc :subject:in-reply-to:references:date:message-id:mime-version :content-type; s=sasl; bh=0GGmnBM/40yupbkml2QUo/3+25Qasnj+hTooCm TdE1I=; b=NeND6UtRXvNbE5oDKMyWck/c/cEOlz5UlORQCV36GwtYDuT+jaeuUi y9E0HOdDtkCeAVDNwKMM9XR5Ko6OPW4eOmNFTo0CTatjKyUhelamHPQZkYpp8nML d3+xFOnAz6iWyAzPEaF6M9TEM1x95335JB8OnjmXq/u6Tje2wvC2c= Received: from pb-smtp21.sea.icgroup.com (unknown [127.0.0.1]) by pb-smtp21.pobox.com (Postfix) with ESMTP id 6C4BE20249; Wed, 26 Jun 2024 12:17:42 -0400 (EDT) (envelope-from junio@pobox.com) Received: from pobox.com (unknown [34.125.219.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by pb-smtp21.pobox.com (Postfix) with ESMTPSA id 0C8BB20248; Wed, 26 Jun 2024 12:17:39 -0400 (EDT) (envelope-from junio@pobox.com) From: Junio C Hamano To: Abhijeet Sonar Cc: Karthik Nayak , git@vger.kernel.org, Paul Millar , Phillip Wood , Elijah Newren , Jeff King Subject: Re: Re* [PATCH v5] describe: refresh the index when 'broken' flag is used In-Reply-To: (Junio C. Hamano's message of "Wed, 26 Jun 2024 08:34:04 -0700") References: <20240626065223.28154-1-abhijeet.nkt@gmail.com> <2e80306e-2474-4254-95eb-c2902a56ffdd@gmail.com> Date: Wed, 26 Jun 2024 09:17:37 -0700 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Pobox-Relay-ID: 9B71C7B6-33D7-11EF-B545-DFF1FEA446E2-77302942!pb-smtp21.pobox.com Junio C Hamano writes: > Subject: [PATCH] fsck: clear child_process after failed run_command() > > There are two loops that calls run_command() using the same > child_process struct near the end of cmd_fsck(). 4d0984be (fsck: do > not reuse child_process structs, 2018-11-12) tightened these code > paths to reinitialize the structure in order to safely reuse it. > > The run-command API makes no promises about what is left in a struct > child_process after a command finishes, and it's not safe to simply > reuse it again for a similar command. > > Upon failure, run_command() can return without releasing the > resource held by the child_process structure, which is done by > calling finish_command() which in turn calls child_process_clear(). Sorry, but I have to take this back. The error return code paths in the start_command() function does seem to call clear_child_process(), which means that there is no need to call clear_child_process() ourselves after a failed run_command() call. The need for reinitializing that established by 4d0984be (fsck: do not reuse child_process structs, 2018-11-12) still stand, so ... the first run ... run_command(&cp); /* no need for separate child_process_clear(&cp) */ child_process_init(&cp); /* prepare for reuse */ ... setup for the second run ... strvec_pushv(&cp.args, diff_index_args); cp.git_cmd = 1; ... full set-up without relying on anything done earlier ... would still be needed. Or alternatively, we could do this to ensure that the child_process structure is always reusable. run-command.c | 1 + run-command.h | 6 +++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git c/run-command.c w/run-command.c index 6ac1d14516..aba250fbe1 100644 --- c/run-command.c +++ w/run-command.c @@ -26,6 +26,7 @@ void child_process_clear(struct child_process *child) { strvec_clear(&child->args); strvec_clear(&child->env); + child_process_init(child); } struct child_to_clean { diff --git c/run-command.h w/run-command.h index 55f6631a2a..6e203c22f6 100644 --- c/run-command.h +++ w/run-command.h @@ -204,7 +204,8 @@ int start_command(struct child_process *); /** * Wait for the completion of a sub-process that was started with - * start_command(). + * start_command(). The child_process structure is cleared and + * reinitialized. */ int finish_command(struct child_process *); @@ -214,6 +215,9 @@ int finish_command_in_signal(struct child_process *); * A convenience function that encapsulates a sequence of * start_command() followed by finish_command(). Takes a pointer * to a `struct child_process` that specifies the details. + * The child_process structure is cleared and reinitialized, + * even when the command fails to start or an error is detected + * in finish_command(). */ int run_command(struct child_process *);