From patchwork Thu Mar 28 20:17:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fan Wu X-Patchwork-Id: 13609549 X-Patchwork-Delegate: paul@paul-moore.com Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 67DA413AA22; Thu, 28 Mar 2024 20:17:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711657057; cv=none; b=AtdXghiQEcmQILAJ1fK/q86+0JopV1q75/tkHTnc7Gvj+BHbZwwiQJ1T3CO2kJsOZjpARenz/J47eMTZIdtoGGoruluC9/Kd+fpBRJ3CHMETwPInUf/l101d+Ml1ZeZ31JWPEes6ac3JSXGQUiZvF6zAGFPB7znx78I7x7EKfNE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711657057; c=relaxed/simple; bh=MoYJ6E1Wd7WrNrkXn+HMX4JdzG8UGPizAvZg5owtETY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=tXn7h6+CvN9Xae3vQBt0y0BAfBdPaJvYJuHIIUtyionoAd+xeP3TJtsD+A70l0sU0+PlBror7TTKQsNQgkT1PbVjvT/Jobd5mBPYgXvdGzyNJHV8b6+j6M7xTJ1QKrHDvfbTZV4AJH4qYEsTTydMfBnYHikc3Zb371iLhkQTBN4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=qVKrTMZ9; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="qVKrTMZ9" Received: by linux.microsoft.com (Postfix, from userid 1052) id 1566020E6F46; Thu, 28 Mar 2024 13:17:28 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 1566020E6F46 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1711657049; bh=JmW+w3GjpzAQDp0EZ3A4BHnSHNwVjunuggdvHyK868o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qVKrTMZ9TwG+6hdejGvm6Tcm39m3XWSL9ghV4cveHwqdp9kH7mPvb/Ff3HDlVWWzc C21tEfNK7UNZhrZakKuF8bzXQKyYikONrBp1s2ziThRRnt7C/RNxJPIqC9LShWnt7s 3T+VK/ICyR/cWIKAyOEzXaw2ObREvhIx/ccovLF8= From: Fan Wu To: corbet@lwn.net, zohar@linux.ibm.com, jmorris@namei.org, serge@hallyn.com, tytso@mit.edu, ebiggers@kernel.org, axboe@kernel.dk, agk@redhat.com, snitzer@kernel.org, eparis@redhat.com, paul@paul-moore.com Cc: linux-doc@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, fsverity@lists.linux.dev, linux-block@vger.kernel.org, dm-devel@lists.linux.dev, audit@vger.kernel.org, linux-kernel@vger.kernel.org, Fan Wu Subject: [PATCH v16 12/20] dm: add finalize hook to target_type Date: Thu, 28 Mar 2024 13:17:19 -0700 Message-Id: <1711657047-10526-13-git-send-email-wufan@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1711657047-10526-1-git-send-email-wufan@linux.microsoft.com> References: <1711657047-10526-1-git-send-email-wufan@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: This patch adds a target finalize hook. The hook is triggered just before activating an inactive table of a mapped device. If it returns an error the __bind get cancelled. The dm-verity target will use this hook to attach the dm-verity's roothash metadata to the block_device struct of the mapped device. Signed-off-by: Fan Wu --- v1-v10: + Not present v11: + Introduced v12: + No changes v13: + No changes v14: + Add documentation v15: + No changes v16: + No changes --- drivers/md/dm.c | 12 ++++++++++++ include/linux/device-mapper.h | 9 +++++++++ 2 files changed, 21 insertions(+) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 56aa2a8b9d71..16d3fd644176 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2270,6 +2270,18 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, goto out; } + for (unsigned int i = 0; i < t->num_targets; i++) { + struct dm_target *ti = dm_table_get_target(t, i); + + if (ti->type->finalize) { + ret = ti->type->finalize(ti); + if (ret) { + old_map = ERR_PTR(ret); + goto out; + } + } + } + old_map = rcu_dereference_protected(md->map, lockdep_is_held(&md->suspend_lock)); rcu_assign_pointer(md->map, (void *)t); md->immutable_target_type = dm_table_get_immutable_target_type(t); diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 82b2195efaca..ad368904b1d5 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -160,6 +160,14 @@ typedef int (*dm_dax_zero_page_range_fn)(struct dm_target *ti, pgoff_t pgoff, */ typedef size_t (*dm_dax_recovery_write_fn)(struct dm_target *ti, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); +/* + * This hook allows DM targets in an inactive table to complete their setup + * before the table is made active. + * Returns: + * < 0 : error + * = 0 : success + */ +typedef int (*dm_finalize_fn) (struct dm_target *target); void dm_error(const char *message); @@ -210,6 +218,7 @@ struct target_type { dm_dax_direct_access_fn direct_access; dm_dax_zero_page_range_fn dax_zero_page_range; dm_dax_recovery_write_fn dax_recovery_write; + dm_finalize_fn finalize; /* For internal device-mapper use. */ struct list_head list;