Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760499AbXEUSXx (ORCPT ); Mon, 21 May 2007 14:23:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756854AbXEUSXq (ORCPT ); Mon, 21 May 2007 14:23:46 -0400 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:39079 "EHLO sous-sol.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756400AbXEUSXq (ORCPT ); Mon, 21 May 2007 14:23:46 -0400 Date: Mon, 21 May 2007 11:21:08 -0700 From: Chris Wright To: Eric Sandeen Cc: Linux Kernel Mailing List , Tejun Heo , stable@kernel.org, Maneesh Soni , Adrian Bunk Subject: Re: [PATCH] - fix oops in sysfs_readdir Message-ID: <20070521182108.GI3429@sequoia.sous-sol.org> References: <4651E0C9.3080609@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4651E0C9.3080609@redhat.com> User-Agent: Mutt/1.5.14 (2007-02-12) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3674 Lines: 103 [Please Cc: Adrian Bunk (added) for 2.6.16-stable material] * Eric Sandeen (sandeen@redhat.com) wrote: > This is a non-ida backport of Tejun's patch in -mm at: > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.22-rc1/2.6.22-rc1-mm1/broken-out/gregkh-driver-sysfs-allocate-inode-number-using-ida.patch > for the 2.6.16 -stable tree - it follows the same scheme of using s_ino to safely > store & retrieve the inode number of sysfs entries for use in sysfs_readdir, > but uses a brain-dead-simple inode nr allocator rather than ida, which would > bring along a lot of newer, more complex code. > > No, this doesn't guarantee uniqueness of sysfs inode numbers, but then > the code in -stable today doesn't either - and with this change, at least > it shouldn't oops. > > Comments? > > Thanks, > > -Eric > > Signed-off-by: Eric Sandeen > > Index: linux-2.6.16.51/fs/sysfs/dir.c > =================================================================== > --- linux-2.6.16.51.orig/fs/sysfs/dir.c > +++ linux-2.6.16.51/fs/sysfs/dir.c > @@ -29,6 +29,14 @@ static struct dentry_operations sysfs_de > .d_iput = sysfs_d_iput, > }; > > +static unsigned int sysfs_inode_counter; > +ino_t sysfs_get_inum(void) > +{ > + if (unlikely(sysfs_inode_counter < 3)) > + sysfs_inode_counter = 3; > + return sysfs_inode_counter++; > +} > + > /* > * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent > */ > @@ -385,7 +393,7 @@ static int sysfs_readdir(struct file * f > > switch (i) { > case 0: > - ino = dentry->d_inode->i_ino; > + ino = parent_sd->s_ino; > if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) > break; > filp->f_pos++; > @@ -415,10 +423,7 @@ static int sysfs_readdir(struct file * f > > name = sysfs_get_name(next); > len = strlen(name); > - if (next->s_dentry) > - ino = next->s_dentry->d_inode->i_ino; > - else > - ino = iunique(sysfs_sb, 2); > + ino = next->s_ino; > > if (filldir(dirent, name, len, filp->f_pos, ino, > dt_type(next)) < 0) > Index: linux-2.6.16.51/fs/sysfs/inode.c > =================================================================== > --- linux-2.6.16.51.orig/fs/sysfs/inode.c > +++ linux-2.6.16.51/fs/sysfs/inode.c > @@ -119,6 +119,7 @@ struct inode * sysfs_new_inode(mode_t mo > inode->i_mapping->a_ops = &sysfs_aops; > inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info; > inode->i_op = &sysfs_inode_operations; > + inode->i_ino = sd->s_ino; > > if (sd->s_iattr) { > /* sysfs_dirent has non-default attributes > Index: linux-2.6.16.51/fs/sysfs/mount.c > =================================================================== > --- linux-2.6.16.51.orig/fs/sysfs/mount.c > +++ linux-2.6.16.51/fs/sysfs/mount.c > @@ -29,6 +29,7 @@ static struct sysfs_dirent sysfs_root = > .s_element = NULL, > .s_type = SYSFS_ROOT, > .s_iattr = NULL, > + .s_ino = 1, > }; > > static int sysfs_fill_super(struct super_block *sb, void *data, int silent) > Index: linux-2.6.16.51/include/linux/sysfs.h > =================================================================== > --- linux-2.6.16.51.orig/include/linux/sysfs.h > +++ linux-2.6.16.51/include/linux/sysfs.h > @@ -72,6 +72,7 @@ struct sysfs_dirent { > void * s_element; > int s_type; > umode_t s_mode; > + ino_t s_ino; > struct dentry * s_dentry; > struct iattr * s_iattr; > }; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/