From patchwork Sat Mar 16 03:35:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fan Wu X-Patchwork-Id: 13594285 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 EF784FBE1; Sat, 16 Mar 2024 03:35:57 +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=1710560163; cv=none; b=dhef+qFzyQlWrxBdDr3GOb6I2Dx0PKW0BZ4z/Q8n6fbUEhvzuf/pHxCL8oi1BLwuLapgb98PjEl+sMaxVc5hI9KiOFDhmHXZCU2zli+XUjlx920Qk7hhB6RRRS02xewjPdoPDdQ2CvvneGImc3qHkjcRKYF5XrntDEG+Q9A4Es8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710560163; c=relaxed/simple; bh=CGol9Yg+mvv8j3MuU5adB+S5Zfdm08E6CNdkO4Pw3e8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=gaRo9B1kVfUfA1q1+etj7unIvQoKKMCAB+kO3ffYCOpJrc7OGnBDdfz15Zc1NHTN00GDmqZURNF4ZzCGzT11hNawhPFlyPfWsfMryXW7R/1Km00ABG/CIz3uTUehcPXd2cbAJk1s/d5RO2Pe9mM74Z0RsUiNcWUtmiRIE7rcRcA= 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=rStFbe//; 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="rStFbe//" Received: by linux.microsoft.com (Postfix, from userid 1052) id EA20C20B74D9; Fri, 15 Mar 2024 20:35:53 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com EA20C20B74D9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1710560153; bh=8UZ8yI1Nl9AJ1CZqfQSY4oqd8EWd1HPQnAJhULnqHQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rStFbe//MNm5gFrEZHDxMrnniZaF/nrd+lZGVoPB6SgZNcOwriBy4iZqOSp/eUZMU FUp2lIddC1EVOobiCvX4vdDaCfFwRPXOk6lG0sQQy2pI+9wyTzvA72Y8o4bpzbg3CY oAl0XjZH9oxHgPIAkynddNJOkKsTdBdUrW6CRKyA= 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: [RFC PATCH v15 13/21] dm: add finalize hook to target_type Date: Fri, 15 Mar 2024 20:35:43 -0700 Message-Id: <1710560151-28904-14-git-send-email-wufan@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1710560151-28904-1-git-send-email-wufan@linux.microsoft.com> References: <1710560151-28904-1-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 --- 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;