From patchwork Mon Sep 25 05:54:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13397265 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21189CE7AAA for ; Mon, 25 Sep 2023 05:59:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232149AbjIYF7U (ORCPT ); Mon, 25 Sep 2023 01:59:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232066AbjIYF7K (ORCPT ); Mon, 25 Sep 2023 01:59:10 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 759B7DF; Sun, 24 Sep 2023 22:58:59 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7002C433CC; Mon, 25 Sep 2023 05:58:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695621539; bh=cz+gERetg21kponi71Jesmq5RBOAugZisOFCZXrnPoE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aOIWr4FQuLTUSVe5DbQnUf8DYvsA6dOLF9Z8hgHs6YuXdu2eRspUt+JKXDxnUaiUc 8yMz1HAIqzuWfvAUNZ8eDM2pWxaSDQZO7eredhZ2tgvTx1x/avI2dukZCuiFPUD+i6 SqqWxscoEtpz3c4VmWJwC8/LwksgCYIjTDTy6KEAptztbp0+QAaSjQYN9c4dIkAVhM zg5Fj17CjuNI3ensjc0Fk+X74jvFedal048aEJ5xpM8xAOaYodPiCV1BkXm65WjjHB PZoi7kMfEj6WHgQ5z2Z6RTGyb/7n9yLpB2ryYMDCWqAcFUGG3SBUU8REcCIr+aXCk9 rOW3vF+8eGmWg== From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-btrfs@vger.kernel.org, Theodore Ts'o , Jaegeuk Kim Subject: [PATCH v3 2/5] fscrypt: make the bounce page pool opt-in instead of opt-out Date: Sun, 24 Sep 2023 22:54:48 -0700 Message-ID: <20230925055451.59499-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230925055451.59499-1-ebiggers@kernel.org> References: <20230925055451.59499-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Eric Biggers Replace FS_CFLG_OWN_PAGES with a bit flag 'needs_bounce_pages' which has the opposite meaning. I.e., filesystems now opt into the bounce page pool instead of opt out. Make fscrypt_alloc_bounce_page() check that the bounce page pool has been initialized. I believe the opt-in makes more sense, since nothing else in fscrypt_operations is opt-out, and these days filesystems can choose to use blk-crypto which doesn't need the fscrypt bounce page pool. Also, I happen to be planning to add two more flags, and I wanted to fix the "FS_CFLG_" name anyway as it wasn't prefixed with "FSCRYPT_". Signed-off-by: Eric Biggers --- fs/ceph/crypto.c | 1 + fs/crypto/crypto.c | 9 ++++++++- fs/ext4/crypto.c | 1 + fs/f2fs/super.c | 1 + fs/ubifs/crypto.c | 1 - include/linux/fscrypt.h | 20 +++++++++++--------- 6 files changed, 22 insertions(+), 11 deletions(-) diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index e4d5cd56a80b9..cc63f1e6fdef6 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -126,20 +126,21 @@ static bool ceph_crypt_empty_dir(struct inode *inode) return ci->i_rsubdirs + ci->i_rfiles == 1; } static const union fscrypt_policy *ceph_get_dummy_policy(struct super_block *sb) { return ceph_sb_to_client(sb)->fsc_dummy_enc_policy.policy; } static struct fscrypt_operations ceph_fscrypt_ops = { + .needs_bounce_pages = 1, .get_context = ceph_crypt_get_context, .set_context = ceph_crypt_set_context, .get_dummy_policy = ceph_get_dummy_policy, .empty_dir = ceph_crypt_empty_dir, }; void ceph_fscrypt_set_ops(struct super_block *sb) { fscrypt_set_ops(sb, &ceph_fscrypt_ops); } diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 6a837e4b80dcb..aed0c5ea75781 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -42,20 +42,27 @@ static DEFINE_MUTEX(fscrypt_init_mutex); struct kmem_cache *fscrypt_info_cachep; void fscrypt_enqueue_decrypt_work(struct work_struct *work) { queue_work(fscrypt_read_workqueue, work); } EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work); struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags) { + if (WARN_ON_ONCE(!fscrypt_bounce_page_pool)) { + /* + * Oops, the filesystem called a function that uses the bounce + * page pool, but it didn't set needs_bounce_pages. + */ + return NULL; + } return mempool_alloc(fscrypt_bounce_page_pool, gfp_flags); } /** * fscrypt_free_bounce_page() - free a ciphertext bounce page * @bounce_page: the bounce page to free, or NULL * * Free a bounce page that was allocated by fscrypt_encrypt_pagecache_blocks(), * or by fscrypt_alloc_bounce_page() directly. */ @@ -318,21 +325,21 @@ EXPORT_SYMBOL(fscrypt_decrypt_block_inplace); int fscrypt_initialize(struct super_block *sb) { int err = 0; mempool_t *pool; /* pairs with smp_store_release() below */ if (likely(smp_load_acquire(&fscrypt_bounce_page_pool))) return 0; /* No need to allocate a bounce page pool if this FS won't use it. */ - if (sb->s_cop->flags & FS_CFLG_OWN_PAGES) + if (!sb->s_cop->needs_bounce_pages) return 0; mutex_lock(&fscrypt_init_mutex); if (fscrypt_bounce_page_pool) goto out_unlock; err = -ENOMEM; pool = mempool_create_page_pool(num_prealloc_crypto_pages, 0); if (!pool) goto out_unlock; diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 99a4769a53f63..5cd7bcfae46b2 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -233,18 +233,19 @@ static bool ext4_has_stable_inodes(struct super_block *sb) } static void ext4_get_ino_and_lblk_bits(struct super_block *sb, int *ino_bits_ret, int *lblk_bits_ret) { *ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count); *lblk_bits_ret = 8 * sizeof(ext4_lblk_t); } const struct fscrypt_operations ext4_cryptops = { + .needs_bounce_pages = 1, .legacy_key_prefix = "ext4:", .get_context = ext4_get_context, .set_context = ext4_set_context, .get_dummy_policy = ext4_get_dummy_policy, .empty_dir = ext4_empty_dir, .has_stable_inodes = ext4_has_stable_inodes, .get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits, }; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index f60062b558fd1..55aa0ed531f22 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -3224,20 +3224,21 @@ static struct block_device **f2fs_get_devices(struct super_block *sb, if (!devs) return ERR_PTR(-ENOMEM); for (i = 0; i < sbi->s_ndevs; i++) devs[i] = FDEV(i).bdev; *num_devs = sbi->s_ndevs; return devs; } static const struct fscrypt_operations f2fs_cryptops = { + .needs_bounce_pages = 1, .legacy_key_prefix = "f2fs:", .get_context = f2fs_get_context, .set_context = f2fs_set_context, .get_dummy_policy = f2fs_get_dummy_policy, .empty_dir = f2fs_empty_dir, .has_stable_inodes = f2fs_has_stable_inodes, .get_ino_and_lblk_bits = f2fs_get_ino_and_lblk_bits, .get_devices = f2fs_get_devices, }; #endif diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c index 1be3e11da3b3e..921f9033d0d2d 100644 --- a/fs/ubifs/crypto.c +++ b/fs/ubifs/crypto.c @@ -81,16 +81,15 @@ int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, if (err) { ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err); return err; } *out_len = clen; return 0; } const struct fscrypt_operations ubifs_crypt_operations = { - .flags = FS_CFLG_OWN_PAGES, .legacy_key_prefix = "ubifs:", .get_context = ubifs_crypt_get_context, .set_context = ubifs_crypt_set_context, .empty_dir = ubifs_crypt_empty_dir, }; diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index b0037566ce308..4505078e89b7e 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -52,32 +52,34 @@ struct fscrypt_name { #define FSTR_INIT(n, l) { .name = n, .len = l } #define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len) #define fname_name(p) ((p)->disk_name.name) #define fname_len(p) ((p)->disk_name.len) /* Maximum value for the third parameter of fscrypt_operations.set_context(). */ #define FSCRYPT_SET_CONTEXT_MAX_SIZE 40 #ifdef CONFIG_FS_ENCRYPTION -/* - * If set, the fscrypt bounce page pool won't be allocated (unless another - * filesystem needs it). Set this if the filesystem always uses its own bounce - * pages for writes and therefore won't need the fscrypt bounce page pool. - */ -#define FS_CFLG_OWN_PAGES (1U << 1) - /* Crypto operations for filesystems */ struct fscrypt_operations { - /* Set of optional flags; see above for allowed flags */ - unsigned int flags; + /* + * If set, then fs/crypto/ will allocate a global bounce page pool the + * first time an encryption key is set up for a file. The bounce page + * pool is required by the following functions: + * + * - fscrypt_encrypt_pagecache_blocks() + * - fscrypt_zeroout_range() for files not using inline crypto + * + * If the filesystem doesn't use those, it doesn't need to set this. + */ + unsigned int needs_bounce_pages : 1; /* * This field exists only for backwards compatibility reasons and should * only be set by the filesystems that are setting it already. It * contains the filesystem-specific key description prefix that is * accepted for "logon" keys for v1 fscrypt policies. This * functionality is deprecated in favor of the generic prefix * "fscrypt:", which itself is deprecated in favor of the filesystem * keyring ioctls such as FS_IOC_ADD_ENCRYPTION_KEY. Filesystems that * are newly adding fscrypt support should not set this field.