From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jiri Kosina , Jiri Slaby Subject: [ 15/23] Revert "sysfs: fix race between readdir and lseek" Date: Tue, 23 Apr 2013 14:56:22 -0700 Message-Id: <20130423215457.836814569@linuxfoundation.org> In-Reply-To: <20130423215456.307216898@linuxfoundation.org> References: <20130423215456.307216898@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Kosina This reverts commit 991f76f837bf22c5bb07261cfd86525a0a96650c in Linus' tree which is f366c8f271888f48e15cc7c0ab70f184c220c8a4 in linux-stable.git It depends on ef3d0fd27e90f ("vfs: do (nearly) lockless generic_file_llseek") which is available only in 3.2+. When applied on 3.0 codebase, it causes A-A deadlock, whenever anyone does seek() on sysfs, as both generic_file_llseek() and sysfs_dir_llseek() obtain i_mutex. Signed-off-by: Jiri Kosina Cc: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -959,21 +959,9 @@ static int sysfs_readdir(struct file * f return 0; } -static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence) -{ - struct inode *inode = file->f_path.dentry->d_inode; - loff_t ret; - - mutex_lock(&inode->i_mutex); - ret = generic_file_llseek(file, offset, whence); - mutex_unlock(&inode->i_mutex); - - return ret; -} - const struct file_operations sysfs_dir_operations = { .read = generic_read_dir, .readdir = sysfs_readdir, .release = sysfs_dir_release, - .llseek = sysfs_dir_llseek, + .llseek = generic_file_llseek, };