From mboxrd@z Thu Jan 1 00:00:00 1970 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 183F5C61D9B for ; Wed, 22 Nov 2023 19:37:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344509AbjKVThC (ORCPT ); Wed, 22 Nov 2023 14:37:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343942AbjKVTg6 (ORCPT ); Wed, 22 Nov 2023 14:36:58 -0500 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [IPv6:2a03:a000:7:0:5054:ff:fe1c:15ff]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 968FB19D; Wed, 22 Nov 2023 11:36:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=mSKI/kF/ejeHo+EBKx8s+JuNIL0q9sqkXoXpNGVtVqI=; b=LqkoXTTqgqMlCQAJ5QbdD+KUHW uMAKXYkMjo/D4JcVUUvgAq3BRImH56DFBksI9uMj3OT564SbAF5UmKtVQ1mACT5R1dD6tP2QTaKnn A6I82CyhEuVTfnl4RBea9t4e8xEnYF71jNq1nqcAO+HUSmtE+rtRmzgn2uOmQ6po4RJ8iv8fQmkqR hA8xrDjtFs3ygp8R/8MFE7SIuW9CH4rypmFSTy8+Bsawf+FWPXl58ktLohSYbUWkrTmtmlYxokjKW GyYYnemfn0PUD5gJISng8I7Lytq+fuY6YdS6aoEyo2LxFYoK+YRc2WEJMIEwmk3GhentERu2taLFD hihENqsg==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1r5t1p-001l1m-0c; Wed, 22 Nov 2023 19:36:53 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Mo Zou , Jan Kara , linux-kernel@vger.kernel.org Subject: [PATCH 5/9] ext4: don't access the source subdirectory content on same-directory rename Date: Wed, 22 Nov 2023 19:36:48 +0000 Message-Id: <20231122193652.419091-5-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231122193652.419091-1-viro@zeniv.linux.org.uk> References: <20231122193028.GE38156@ZenIV> <20231122193652.419091-1-viro@zeniv.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We can't really afford locking the source on same-directory rename; currently vfs_rename() tries to do that, but it will have to be changed. The logics in ext4 is lazy and goes looking for ".." in source even in same-directory case. It's not hard to get rid of that, leaving that behaviour only for cross-directory case; that VFS can get locks safely (and will keep doing that after the coming changes). Signed-off-by: Al Viro --- fs/ext4/namei.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index d252935f9c8a..467ba47a691c 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3591,10 +3591,14 @@ struct ext4_renament { int dir_inlined; }; -static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) +static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent, bool is_cross) { int retval; + ent->is_dir = true; + if (!is_cross) + return 0; + ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, &retval, &ent->parent_de, &ent->dir_inlined); @@ -3612,6 +3616,9 @@ static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, { int retval; + if (!ent->dir_bh) + return 0; + ent->parent_de->inode = cpu_to_le32(dir_ino); BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); if (!ent->dir_inlined) { @@ -3900,7 +3907,7 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir, if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) goto end_rename; } - retval = ext4_rename_dir_prepare(handle, &old); + retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir); if (retval) goto end_rename; } @@ -3964,7 +3971,7 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir, } inode_set_mtime_to_ts(old.dir, inode_set_ctime_current(old.dir)); ext4_update_dx_flag(old.dir); - if (old.dir_bh) { + if (old.is_dir) { retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); if (retval) goto end_rename; @@ -3987,7 +3994,7 @@ static int ext4_rename(struct mnt_idmap *idmap, struct inode *old_dir, if (unlikely(retval)) goto end_rename; - if (S_ISDIR(old.inode->i_mode)) { + if (old.is_dir) { /* * We disable fast commits here that's because the * replay code is not yet capable of changing dot dot @@ -4114,14 +4121,12 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, ext4_handle_sync(handle); if (S_ISDIR(old.inode->i_mode)) { - old.is_dir = true; - retval = ext4_rename_dir_prepare(handle, &old); + retval = ext4_rename_dir_prepare(handle, &old, new.dir != old.dir); if (retval) goto end_rename; } if (S_ISDIR(new.inode->i_mode)) { - new.is_dir = true; - retval = ext4_rename_dir_prepare(handle, &new); + retval = ext4_rename_dir_prepare(handle, &new, new.dir != old.dir); if (retval) goto end_rename; } -- 2.39.2