From patchwork Mon Nov 20 23:51:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13462312 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 98C9131581 for ; Mon, 20 Nov 2023 23:51:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25666C433C8; Mon, 20 Nov 2023 23:51:39 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97-RC3) (envelope-from ) id 1r5E3W-00000002Po8-2Nff; Mon, 20 Nov 2023 18:51:54 -0500 Message-ID: <20231120235154.422970988@goodmis.org> User-Agent: quilt/0.67 Date: Mon, 20 Nov 2023 18:51:07 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , Naresh Kamboju , Linux Kernel Functional Testing Subject: [PATCH 2/2] eventfs: Do not invalidate dentry in create_file/dir_dentry() References: <20231120235105.834774147@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Steven Rostedt (Google)" With the call to simple_recursive_removal() on the entire eventfs sub system when the directory is removed, it performs the d_invalidate on all the dentries when it is removed. There's no need to do clean ups when a dentry is being created while the directory is being deleted. As dentries are cleaned up by the simpler_recursive_removal(), trying to do d_invalidate() in these functions will cause the dentry to be invalidated twice, and crash the kernel. Link: https://lore.kernel.org/all/20231116123016.140576-1-naresh.kamboju@linaro.org/ Fixes: 407c6726ca71 ("eventfs: Use simple_recursive_removal() to clean up dentries") Reported-by: Mark Rutland Reported-by: Naresh Kamboju Reported-by: Linux Kernel Functional Testing Signed-off-by: Steven Rostedt (Google) --- fs/tracefs/event_inode.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index f239b2b507a4..3eb6c622a74d 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -326,7 +326,6 @@ create_file_dentry(struct eventfs_inode *ei, int idx, struct eventfs_attr *attr = NULL; struct dentry **e_dentry = &ei->d_children[idx]; struct dentry *dentry; - bool invalidate = false; mutex_lock(&eventfs_mutex); if (ei->is_freed) { @@ -389,17 +388,14 @@ create_file_dentry(struct eventfs_inode *ei, int idx, * Otherwise it means two dentries exist with the same name. */ WARN_ON_ONCE(!ei->is_freed); - invalidate = true; + dentry = NULL; } mutex_unlock(&eventfs_mutex); - if (invalidate) - d_invalidate(dentry); - - if (lookup || invalidate) + if (lookup) dput(dentry); - return invalidate ? NULL : dentry; + return dentry; } /** @@ -439,7 +435,6 @@ static struct dentry * create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei, struct dentry *parent, bool lookup) { - bool invalidate = false; struct dentry *dentry = NULL; mutex_lock(&eventfs_mutex); @@ -495,16 +490,14 @@ create_dir_dentry(struct eventfs_inode *pei, struct eventfs_inode *ei, * Otherwise it means two dentries exist with the same name. */ WARN_ON_ONCE(!ei->is_freed); - invalidate = true; + dentry = NULL; } mutex_unlock(&eventfs_mutex); - if (invalidate) - d_invalidate(dentry); - if (lookup || invalidate) + if (lookup) dput(dentry); - return invalidate ? NULL : dentry; + return dentry; } /**