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 AF6F57407A; Thu, 18 Jul 2024 14:26:00 +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=1721312760; cv=none; b=Osw4yltu6qiXbjNQXv3ZF8qtiJJbA25qsfcv2aV6gGnHRG3RuxIZNiSACl0uyzEhzo7d6TW5QUpW5732yLk0FMDtjWiv+/zHdlW8nS5UmITA9hNpHzVPSC3vBmjk6r01fMhGk/bvdFLwnztMPG1/I2rY2j6iyXfHgLQVoaAN+qk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721312760; c=relaxed/simple; bh=QxLSqqLbgC1YAN8cOfg/sJdekq31+FJBrmTDn9ZCo0s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fG+aSYPGIBA6KmQqGR5kU1z8OmLShaotGbZUEr/4qfcKNQ60RprZAOOO3l9Hr89G43FAvS1DtCzTYxkome+SPtYOWvEUp6AR4LwO57pxKIZAggAg40M1n5ARc6tFBZX4luYbsSq+RXGnOo7VU7DbhdmvKoAmYKGF/hBxLWHH33Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Mhy3BoSb; 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="Mhy3BoSb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0DF91C116B1; Thu, 18 Jul 2024 14:25:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721312760; bh=QxLSqqLbgC1YAN8cOfg/sJdekq31+FJBrmTDn9ZCo0s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Mhy3BoSbLRrU1aGVs2AovY+gKjIc4A7t4lpo/kHUv3tTTmCP02ca24SubGNhFjPET PDyulwahROXlaD8jPDYVqwvXaQjXiLRhhfvwNFlmhSYKxiRnrD2rx8QWuqXgaKpc4y i2rYfM5yTdHePmbj6i5sJR6GSIoXhiuc61tk8M+XJ8+bS3X37VVAnxsxa8jb7owje9 tRKEMmbzNVfT/YKrMZVHM5Gyyc2tvqweLoBoDa73uxo28I7J0O8PE5aWBy8q1J5KHm ThTclwPaiQTqDT2PPRe7MmVAoarzFc6NjtWOSBtbQsM6jOOTvsWsKvFUq0QRcgQMng skl1bKMhDNg+Q== Date: Thu, 18 Jul 2024 10:25:58 -0400 From: Mike Snitzer To: Khazhismel Kumykov Cc: Mikulas Patocka , Alasdair Kergon , Zdenek Kabelac , Joe Thornber , Heinz Mauelshagen , dm-devel@lists.linux.dev, linux-kernel@vger.kernel.org, Khazhismel Kumykov Subject: Re: [RFC PATCH v2] dm ioctl: fix erroneous EINVAL when signaled Message-ID: References: <20240717231833.2090430-1-khazhy@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240717231833.2090430-1-khazhy@google.com> On Wed, Jul 17, 2024 at 04:18:33PM -0700, Khazhismel Kumykov wrote: > do_resume when loading a new map first calls dm_suspend, which could > silently fail. When we proceeded to dm_swap_table, we would bail out > with EINVAL. Instead, attempt to restore new_map and return ERESTARTSYS > when signaled. > > Signed-off-by: Khazhismel Kumykov > --- > drivers/md/dm-ioctl.c | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) > > v2: don't leak new_map if we can't assign it back to hc. > > diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c > index c2c07bfa6471..0591455ad63c 100644 > --- a/drivers/md/dm-ioctl.c > +++ b/drivers/md/dm-ioctl.c > @@ -1181,8 +1181,27 @@ static int do_resume(struct dm_ioctl *param) > suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; > if (param->flags & DM_NOFLUSH_FLAG) > suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; > - if (!dm_suspended_md(md)) > - dm_suspend(md, suspend_flags); > + if (!dm_suspended_md(md)) { > + r = dm_suspend(md, suspend_flags); > + if (r == -EINTR) > + r = -ERESTARTSYS; > + if (r) { > + down_write(&_hash_lock); > + hc = dm_get_mdptr(md); > + if (!hc) > + r = -ENXIO; > + if (hc && !hc->new_map) { > + hc->new_map = new_map; > + up_write(&_hash_lock); > + } else { > + up_write(&_hash_lock); > + dm_sync_table(md); > + dm_table_destroy(new_map); > + } > + dm_put(md); > + return r; > + } > + } > > old_size = dm_get_size(md); > old_map = dm_swap_table(md, new_map); > -- > 2.45.2.993.g49e7a77208-goog > > Thanks for the patch. The header could use more context for how this issue has caused problems in practice (you touched on that in reply to Mikulas for v1). But I will review this closely starting the week of July 29. This is a very fundamental codepath for DM so needs extended review. Mike