From patchwork Thu Sep 17 04:11:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11781475 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 95B70618 for ; Thu, 17 Sep 2020 04:20:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A5A2206A2 for ; Thu, 17 Sep 2020 04:20:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600316451; bh=WmCmKZhgAhAAx8A2nTwm5+ud6oD6KRjcfUOh3w6Nj+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=W4+WIgpP1eSvSfChOZWsKipkS16mCu8oIPhh54vScNY9AcRjKpLfOCqM124stGiHK scoL4O4/wC8rQ5VRMbogcIXdIPcVo5FoNDBpnvgElYpkR1LSrfUbKtyO1gXIAIVWcf FKjwrEi7yVGHYKpC9UO/z/jF1eNEYpqZyQiQb94g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726249AbgIQEUu (ORCPT ); Thu, 17 Sep 2020 00:20:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:33842 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726152AbgIQEUs (ORCPT ); Thu, 17 Sep 2020 00:20:48 -0400 Received: from sol.attlocal.net (172-10-235-113.lightspeed.sntcca.sbcglobal.net [172.10.235.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0ACA221974; Thu, 17 Sep 2020 04:13:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600315989; bh=WmCmKZhgAhAAx8A2nTwm5+ud6oD6KRjcfUOh3w6Nj+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rdqA4Zqn2oaBng6V9F1Px3UmOIYQbeuhmqepDUt+j2fRbBUbR0D0FqWivkO/ROluo upb5uyLLpKTc7/uXqKOcEhzdnSYGLzgJYuiSnRvCqWkfn1aLKq1/V60GKXNRhYRcU/ fy6D6dQrVEkL17vCD5JeV+Vx09RJd89g8Ic33riQ= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, ceph-devel@vger.kernel.org, Jeff Layton , Daniel Rosenberg , Jaegeuk Kim Subject: [PATCH v3 04/13] f2fs: use fscrypt_prepare_new_inode() and fscrypt_set_context() Date: Wed, 16 Sep 2020 21:11:27 -0700 Message-Id: <20200917041136.178600-5-ebiggers@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200917041136.178600-1-ebiggers@kernel.org> References: <20200917041136.178600-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org From: Eric Biggers Convert f2fs to use the new functions fscrypt_prepare_new_inode() and fscrypt_set_context(). This avoids calling fscrypt_get_encryption_info() from under f2fs_lock_op(), which can deadlock because fscrypt_get_encryption_info() isn't GFP_NOFS-safe. For more details about this problem, see the earlier patch "fscrypt: add fscrypt_prepare_new_inode() and fscrypt_set_context()". This also fixes a f2fs-specific deadlock when the filesystem is mounted with '-o test_dummy_encryption' and a file is created in an unencrypted directory other than the root directory: INFO: task touch:207 blocked for more than 30 seconds. Not tainted 5.9.0-rc4-00099-g729e3d0919844 #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:touch state:D stack: 0 pid: 207 ppid: 167 flags:0x00000000 Call Trace: [...] lock_page include/linux/pagemap.h:548 [inline] pagecache_get_page+0x25e/0x310 mm/filemap.c:1682 find_or_create_page include/linux/pagemap.h:348 [inline] grab_cache_page include/linux/pagemap.h:424 [inline] f2fs_grab_cache_page fs/f2fs/f2fs.h:2395 [inline] f2fs_grab_cache_page fs/f2fs/f2fs.h:2373 [inline] __get_node_page.part.0+0x39/0x2d0 fs/f2fs/node.c:1350 __get_node_page fs/f2fs/node.c:35 [inline] f2fs_get_node_page+0x2e/0x60 fs/f2fs/node.c:1399 read_inline_xattr+0x88/0x140 fs/f2fs/xattr.c:288 lookup_all_xattrs+0x1f9/0x2c0 fs/f2fs/xattr.c:344 f2fs_getxattr+0x9b/0x160 fs/f2fs/xattr.c:532 f2fs_get_context+0x1e/0x20 fs/f2fs/super.c:2460 fscrypt_get_encryption_info+0x9b/0x450 fs/crypto/keysetup.c:472 fscrypt_inherit_context+0x2f/0xb0 fs/crypto/policy.c:640 f2fs_init_inode_metadata+0xab/0x340 fs/f2fs/dir.c:540 f2fs_add_inline_entry+0x145/0x390 fs/f2fs/inline.c:621 f2fs_add_dentry+0x31/0x80 fs/f2fs/dir.c:757 f2fs_do_add_link+0xcd/0x130 fs/f2fs/dir.c:798 f2fs_add_link fs/f2fs/f2fs.h:3234 [inline] f2fs_create+0x104/0x290 fs/f2fs/namei.c:344 lookup_open.isra.0+0x2de/0x500 fs/namei.c:3103 open_last_lookups+0xa9/0x340 fs/namei.c:3177 path_openat+0x8f/0x1b0 fs/namei.c:3365 do_filp_open+0x87/0x130 fs/namei.c:3395 do_sys_openat2+0x96/0x150 fs/open.c:1168 [...] That happened because f2fs_add_inline_entry() locks the directory inode's page in order to add the dentry, then f2fs_get_context() tries to lock it recursively in order to read the encryption xattr. This problem is specific to "test_dummy_encryption" because normally the directory's fscrypt_info would be set up prior to f2fs_add_inline_entry() in order to encrypt the new filename. Regardless, the new design fixes this test_dummy_encryption deadlock as well as potential deadlocks with fs reclaim, by setting up any needed fscrypt_info structs prior to taking so many locks. The test_dummy_encryption deadlock was reported by Daniel Rosenberg. Reported-by: Daniel Rosenberg Acked-by: Jaegeuk Kim Signed-off-by: Eric Biggers --- fs/f2fs/dir.c | 2 +- fs/f2fs/f2fs.h | 23 ----------------------- fs/f2fs/namei.c | 7 ++++++- 3 files changed, 7 insertions(+), 25 deletions(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index b2530b9507bd9..414bc94fbd546 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -537,7 +537,7 @@ struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir, goto put_error; if (IS_ENCRYPTED(inode)) { - err = fscrypt_inherit_context(dir, inode, page, false); + err = fscrypt_set_context(inode, page); if (err) goto put_error; } diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index d9e52a7f3702f..0503371f88ed4 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1315,13 +1315,6 @@ enum fsync_mode { #define IS_IO_TRACED_PAGE(page) (0) #endif -#ifdef CONFIG_FS_ENCRYPTION -#define DUMMY_ENCRYPTION_ENABLED(sbi) \ - (unlikely(F2FS_OPTION(sbi).dummy_enc_ctx.ctx != NULL)) -#else -#define DUMMY_ENCRYPTION_ENABLED(sbi) (0) -#endif - /* For compression */ enum compress_algorithm_type { COMPRESS_LZO, @@ -4022,22 +4015,6 @@ static inline bool f2fs_lfs_mode(struct f2fs_sb_info *sbi) return F2FS_OPTION(sbi).fs_mode == FS_MODE_LFS; } -static inline bool f2fs_may_encrypt(struct inode *dir, struct inode *inode) -{ -#ifdef CONFIG_FS_ENCRYPTION - struct f2fs_sb_info *sbi = F2FS_I_SB(dir); - umode_t mode = inode->i_mode; - - /* - * If the directory encrypted or dummy encryption enabled, - * then we should encrypt the inode. - */ - if (IS_ENCRYPTED(dir) || DUMMY_ENCRYPTION_ENABLED(sbi)) - return (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)); -#endif - return false; -} - static inline bool f2fs_may_compress(struct inode *inode) { if (IS_SWAPFILE(inode) || f2fs_is_pinned_file(inode) || diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index 84e4bbc1a64de..45f324511a19e 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -28,6 +28,7 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode) nid_t ino; struct inode *inode; bool nid_free = false; + bool encrypt = false; int xattr_size = 0; int err; @@ -69,13 +70,17 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode) F2FS_I(inode)->i_projid = make_kprojid(&init_user_ns, F2FS_DEF_PROJID); + err = fscrypt_prepare_new_inode(dir, inode, &encrypt); + if (err) + goto fail_drop; + err = dquot_initialize(inode); if (err) goto fail_drop; set_inode_flag(inode, FI_NEW_INODE); - if (f2fs_may_encrypt(dir, inode)) + if (encrypt) f2fs_set_encrypted_inode(inode); if (f2fs_sb_has_extra_attr(sbi)) {