From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 4 Jul 2002 02:24:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 4 Jul 2002 02:24:35 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.101]:36829 "EHLO e1.ny.us.ibm.com") by vger.kernel.org with ESMTP id ; Thu, 4 Jul 2002 02:24:32 -0400 Message-ID: <3D23EA93.7090106@us.ibm.com> Date: Wed, 03 Jul 2002 23:26:27 -0700 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020607 X-Accept-Language: en-us, en MIME-Version: 1.0 To: mochel@osdl.org CC: Greg KH , linux-kernel@vger.kernel.org Subject: [PATCH] remove BKL from driverfs Content-Type: multipart/mixed; boundary="------------060006010200090105010605" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is a multi-part message in MIME format. --------------060006010200090105010605 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit I saw your talk about driverfs at OLS and it got my attention. When my BKL debugging patch showed some use of the BKL in driverfs, I was very dissapointed (you can blame Greg if you want). text from dmesg after BKL debugging patch: release of recursive BKL hold, depth: 1 [ 0]main:492 [ 1]inode:149 I see no reason to hold the BKL in your situation. I replaced it with i_sem in some places and just plain removed it in others. I believe that you get all of the protection that you need from dcache_lock in the dentry insert and activate. Can you prove me wrong? -- Dave Hansen haveblue@us.ibm.com --------------060006010200090105010605 Content-Type: text/plain; name="driverfs-bkl_remove-2.5.24-0.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="driverfs-bkl_remove-2.5.24-0.patch" --- linux-2.5.24-clean/fs/driverfs/inode.c Thu Jun 20 15:53:45 2002 +++ linux/fs/driverfs/inode.c Wed Jul 3 23:18:23 2002 @@ -146,20 +146,16 @@ static int driverfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) { int res; - lock_kernel(); dentry->d_op = &driverfs_dentry_dir_ops; res = driverfs_mknod(dir, dentry, mode | S_IFDIR, 0); - unlock_kernel(); return res; } static int driverfs_create(struct inode *dir, struct dentry *dentry, int mode) { int res; - lock_kernel(); dentry->d_op = &driverfs_dentry_file_ops; res = driverfs_mknod(dir, dentry, mode | S_IFREG, 0); - unlock_kernel(); return res; } @@ -211,9 +207,9 @@ if (driverfs_empty(dentry)) { struct inode *inode = dentry->d_inode; - lock_kernel(); + down(&inode->i_sem); inode->i_nlink--; - unlock_kernel(); + up(&inode->i_sem); dput(dentry); error = 0; } @@ -353,8 +349,9 @@ driverfs_file_lseek(struct file *file, loff_t offset, int orig) { loff_t retval = -EINVAL; + struct inode *inode = file->f_dentry->d_inode->i_mapping->host; - lock_kernel(); + down(&inode->i_sem); switch(orig) { case 0: if (offset > 0) { @@ -371,7 +368,7 @@ default: break; } - unlock_kernel(); + up(&inode->i_sem); return retval; } --------------060006010200090105010605--