From patchwork Wed Mar 6 23:34:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fan Wu X-Patchwork-Id: 13584874 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 E04AA1C6B8; Wed, 6 Mar 2024 23:34:55 +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=1709768099; cv=none; b=mJg/WFa+QA+RJH4fT8CBKaaUS+risodJgh80Q4NbsAsjC4wgI1V1xS7mDUWisyth56N3z3f27Nj3Fk2gQXnR2FrbD/asZCrQw1AB8Wv6jI+rG9HoGdvfGsKKMLKbek5qZwXxSWDpTX8LLXFIvpgcCpTTWKeRa9s+5GPZ+LrV1JY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709768099; c=relaxed/simple; bh=5ciSuXFcPAqlMScKCh/OLg/cYFaZ/I5HXIYem2MOpQ8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=XcnnfiNehFhxyToXvnIDK0abJnAnpCADbQ/2mxdkpYiWXz0jgsPRGPd8r8gXbSnxFKUqjDVL2yHKFje59vePrcHCgvNVmar1VfpvkclLiB7FlZZS6LoOSYprlxkD7xzhYEvSramy5DH1jvpdF/6Caktgu0iv2cqiCko75AgS9Tw= 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=aVX0wA0t; 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="aVX0wA0t" Received: by linux.microsoft.com (Postfix, from userid 1052) id 9FE1320B74D7; Wed, 6 Mar 2024 15:34:52 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9FE1320B74D7 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1709768092; bh=DP7pJ46XQmOmQeW5xINRR1Wcr/qDmQzA4z6vIZOePrk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aVX0wA0thVq0M9WLE3ctF1SL4Cx9hIEG6176FnFX85NIowWRkdGTa4HOkTxT71rlV lkDHDtJ0j0EhXbYUUByy44Hhbo5l58M0UusieEu+RZn8E5090qoyhlycgoSQ6PY/n3 Oge/4bG/F9OR5wWsfUdJ/9lHRW9LXNIF0tGICSik= 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, linux-fscrypt@vger.kernel.org, linux-block@vger.kernel.org, dm-devel@lists.linux.dev, audit@vger.kernel.org, linux-kernel@vger.kernel.org, Fan Wu Subject: [RFC PATCH v14 12/19] dm: add finalize hook to target_type Date: Wed, 6 Mar 2024 15:34:37 -0800 Message-Id: <1709768084-22539-13-git-send-email-wufan@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1709768084-22539-1-git-send-email-wufan@linux.microsoft.com> References: <1709768084-22539-1-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 --- 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 8dcabf84d866..15b46edae49f 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2266,6 +2266,18 @@ 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 772ab4d74d94..d7a0ba1fa19e 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;