From patchwork Sun Jul 17 04:35:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12920434 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 93139C433EF for ; Sun, 17 Jul 2022 04:36:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232489AbiGQEgS (ORCPT ); Sun, 17 Jul 2022 00:36:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229772AbiGQEgR (ORCPT ); Sun, 17 Jul 2022 00:36:17 -0400 Received: from smtp-fw-9103.amazon.com (smtp-fw-9103.amazon.com [207.171.188.200]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D854E20F57 for ; Sat, 16 Jul 2022 21:36:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1658032576; x=1689568576; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=64I0h5SoR9M9pZ2dpqmM782CcnZdypZufhDR1of5wnA=; b=hWJdxSuAw+tnIl4eD3xPZEOy6l2d6ttN9KFQp5og51mSd1IN175XZUTz Tjvlq53l3UzVMsMIrGeypCJtiuT5tY3S786IcFAS3jm5IWXBkxJJfAgp1 U1iMsG1xH3PhwFHFJPpqetX5f7xr23L/oAdPf4zW0AiRXYwZbXrviDVK7 Q=; X-IronPort-AV: E=Sophos;i="5.92,278,1650931200"; d="scan'208";a="1034913791" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO email-inbound-relay-pdx-2b-c275e159.us-west-2.amazon.com) ([10.25.36.214]) by smtp-border-fw-9103.sea19.amazon.com with ESMTP; 17 Jul 2022 04:36:01 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-pdx-2b-c275e159.us-west-2.amazon.com (Postfix) with ESMTPS id 970D69A239; Sun, 17 Jul 2022 04:36:01 +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; Sun, 17 Jul 2022 04:36:00 +0000 Received: from 88665a182662.ant.amazon.com (10.43.162.124) 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; Sun, 17 Jul 2022 04:35:58 +0000 From: Kuniyuki Iwashima To: Jeff Layton , Chuck Lever , Alexander Viro CC: Kuniyuki Iwashima , Kuniyuki Iwashima , Subject: [PATCH v3 1/2] fs/lock: Don't allocate file_lock in flock_make_lock(). Date: Sat, 16 Jul 2022 21:35:31 -0700 Message-ID: <20220717043532.35821-2-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220717043532.35821-1-kuniyu@amazon.com> References: <20220717043532.35821-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.162.124] X-ClientProxiedBy: EX13d09UWC001.ant.amazon.com (10.43.162.60) 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 --- fs/locks.c | 46 +++++++++++++++------------------------------- 1 file changed, 15 insertions(+), 31 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index ca28e0e50e56..b134eaefd7d6 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) @@ -2097,10 +2083,9 @@ EXPORT_SYMBOL(locks_lock_inode_wait); */ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) { + int can_sleep, error, unlock, type; struct fd f = fdget(fd); - struct file_lock *lock; - int can_sleep, unlock; - int error; + struct file_lock fl; error = -EBADF; if (!f.file) @@ -2127,28 +2112,27 @@ 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); + type = flock_translate_cmd(cmd); + if (type < 0) { + error = type; 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); + &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); @@ -2614,7 +2598,7 @@ 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, F_UNLCK); fl.fl_flags |= FL_CLOSE; if (filp->f_op->flock)