From: Greg KH Subject: [patch 080/104] ext4: fix #11321: create /proc/ext4/*/stats more carefully Date: Wed, 3 Dec 2008 11:56:06 -0800 Message-ID: <20081203195606.GC8950@kroah.com> References: <20081203193901.715896543@mini.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Justin Forbes , Zwane Mwaikambo , Theodore Ts'o , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ext4 Developers List , Alexey Dobriyan To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:56564 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753236AbYLCT5l (ORCPT ); Wed, 3 Dec 2008 14:57:41 -0500 Content-Disposition: inline; filename="ext4-fix-11321-create-proc-ext4-stats-more-carefully.patch" In-Reply-To: <20081203194725.GA8950@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Alexey Dobriyan (cherry picked from commit 899fc1a4cf404747de2666534d508804597ee22f) ext4 creates per-suberblock directory in /proc/ext4/ . Name used as basis is taken from bdevname, which, surprise, can contain slash. However, proc while allowing to use proc_create("a/b", parent) form of PDE creation, assumes that parent/a was already created. bdevname in question is 'cciss/c0d0p9', directory is not created and all this stuff goes directly into /proc (which is real bug). Warning comes when _second_ partition is mounted. http://bugzilla.kernel.org/show_bug.cgi?id=11321 Signed-off-by: Alexey Dobriyan Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2785,14 +2785,20 @@ static int ext4_mb_init_per_dev_proc(str mode_t mode = S_IFREG | S_IRUGO | S_IWUSR; struct ext4_sb_info *sbi = EXT4_SB(sb); struct proc_dir_entry *proc; - char devname[64]; + char devname[BDEVNAME_SIZE], *p; if (proc_root_ext4 == NULL) { sbi->s_mb_proc = NULL; return -EINVAL; } bdevname(sb->s_bdev, devname); + p = devname; + while ((p = strchr(p, '/'))) + *p = '!'; + sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4); + if (!sbi->s_mb_proc) + goto err_create_dir; MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats); MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan); @@ -2804,7 +2810,6 @@ static int ext4_mb_init_per_dev_proc(str return 0; err_out: - printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname); remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc); remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc); remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc); @@ -2813,6 +2818,8 @@ err_out: remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc); remove_proc_entry(devname, proc_root_ext4); sbi->s_mb_proc = NULL; +err_create_dir: + printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname); return -ENOMEM; } @@ -2820,12 +2827,15 @@ err_out: static int ext4_mb_destroy_per_dev_proc(struct super_block *sb) { struct ext4_sb_info *sbi = EXT4_SB(sb); - char devname[64]; + char devname[BDEVNAME_SIZE], *p; if (sbi->s_mb_proc == NULL) return -EINVAL; bdevname(sb->s_bdev, devname); + p = devname; + while ((p = strchr(p, '/'))) + *p = '!'; remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc); remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc); remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);