From patchwork Sat Jul 16 01:31:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12919936 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 133F2C43334 for ; Sat, 16 Jul 2022 01:32:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231236AbiGPBcM (ORCPT ); Fri, 15 Jul 2022 21:32:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230072AbiGPBcL (ORCPT ); Fri, 15 Jul 2022 21:32:11 -0400 Received: from smtp-fw-6002.amazon.com (smtp-fw-6002.amazon.com [52.95.49.90]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A0BA43E7A for ; Fri, 15 Jul 2022 18:32:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657935127; x=1689471127; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=42pGIUa9Q6IV6yCVU6D7hjavW4N5MHMYFeIuv3o8epI=; b=lOYqhG+ed1UNeV3wrvwu2rxwwbcGuGXQgwTd3lhwEh6gbrzECreH1h0r jPAmZuSx8Fpu07O4ACSzf+vqvrkozpZM/yl24xGhR23YEfcksfKw/GVem 5rBpZ6D5UHjKlr5oMGF0/sYfOo6VkgUHQwfQGdZ4zfyAKnOOb2TR24I38 g=; X-IronPort-AV: E=Sophos;i="5.92,275,1650931200"; d="scan'208";a="222364099" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-iad-1d-9a235a16.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-6002.iad6.amazon.com with ESMTP; 16 Jul 2022 01:31:54 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1d-9a235a16.us-east-1.amazon.com (Postfix) with ESMTPS id 57344800CE; Sat, 16 Jul 2022 01:31:53 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Sat, 16 Jul 2022 01:31:52 +0000 Received: from 88665a182662.ant.amazon.com (10.43.161.172) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Sat, 16 Jul 2022 01:31:50 +0000 From: Kuniyuki Iwashima To: Jeff Layton , Chuck Lever , Alexander Viro CC: Kuniyuki Iwashima , Kuniyuki Iwashima , Subject: [PATCH] fs/lock: Don't allocate file_lock in flock_make_lock(). Date: Fri, 15 Jul 2022 18:31:40 -0700 Message-ID: <20220716013140.61445-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Originating-IP: [10.43.161.172] X-ClientProxiedBy: EX13D40UWA003.ant.amazon.com (10.43.160.29) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Two functions, flock syscall and locks_remove_flock(), call flock_make_lock(). It allocates struct file_lock from slab cache if its argument fl is NULL. When we call flock syscall, we pass NULL to allocate memory for struct file_lock. However, we always free it at the end by locks_free_lock(). We need not allocate it and instead should use a local variable as locks_remove_flock() does. Also, the validation for flock_translate_cmd() is not necessary for locks_remove_flock(). So we move the part to flock syscall and make flock_make_lock() return nothing. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Chuck Lever Reported-by: kernel test robot Reported-by: kernel test robot --- fs/locks.c | 57 +++++++++++++++++++----------------------------------- 1 file changed, 20 insertions(+), 37 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index ca28e0e50e56..db75f4537abc 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -425,21 +425,9 @@ static inline int flock_translate_cmd(int cmd) { } /* Fill in a file_lock structure with an appropriate FLOCK lock. */ -static struct file_lock * -flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) +static void flock_make_lock(struct file *filp, struct file_lock *fl, int type) { - int type = flock_translate_cmd(cmd); - - if (type < 0) - return ERR_PTR(type); - - if (fl == NULL) { - fl = locks_alloc_lock(); - if (fl == NULL) - return ERR_PTR(-ENOMEM); - } else { - locks_init_lock(fl); - } + locks_init_lock(fl); fl->fl_file = filp; fl->fl_owner = filp; @@ -447,8 +435,6 @@ flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl) fl->fl_flags = FL_FLOCK; fl->fl_type = type; fl->fl_end = OFFSET_MAX; - - return fl; } static int assign_type(struct file_lock *fl, long type) @@ -2097,14 +2083,18 @@ EXPORT_SYMBOL(locks_lock_inode_wait); */ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) { - struct fd f = fdget(fd); - struct file_lock *lock; - int can_sleep, unlock; + int can_sleep, unlock, type; + struct file_lock fl; + struct fd f; int error; - error = -EBADF; + type = flock_translate_cmd(cmd); + if (type < 0) + return type; + + f = fdget(fd); if (!f.file) - goto out; + return -EBADF; can_sleep = !(cmd & LOCK_NB); cmd &= ~LOCK_NB; @@ -2127,32 +2117,25 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) goto out_putf; } - lock = flock_make_lock(f.file, cmd, NULL); - if (IS_ERR(lock)) { - error = PTR_ERR(lock); - goto out_putf; - } + flock_make_lock(f.file, &fl, type); if (can_sleep) - lock->fl_flags |= FL_SLEEP; + fl.fl_flags |= FL_SLEEP; - error = security_file_lock(f.file, lock->fl_type); + error = security_file_lock(f.file, fl.fl_type); if (error) - goto out_free; + goto out_putf; if (f.file->f_op->flock) error = f.file->f_op->flock(f.file, - (can_sleep) ? F_SETLKW : F_SETLK, - lock); + can_sleep ? F_SETLKW : F_SETLK, + &fl); else - error = locks_lock_file_wait(f.file, lock); - - out_free: - locks_free_lock(lock); + error = locks_lock_file_wait(f.file, &fl); out_putf: fdput(f); - out: + return error; } @@ -2614,7 +2597,7 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx) if (list_empty(&flctx->flc_flock)) return; - flock_make_lock(filp, LOCK_UN, &fl); + flock_make_lock(filp, &fl, flock_translate_cmd(LOCK_UN)); fl.fl_flags |= FL_CLOSE; if (filp->f_op->flock)