From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: Re: [Bug] possible circular locking in reiserfs_unpack Date: Thu, 09 Sep 2010 16:55:34 +0200 Message-ID: <4C88F566.7080600@gmail.com> References: <20100905113121.GA1876@del.dom.local> <20100908153730.5ad13f71.akpm@linux-foundation.org> <20100909015346.GA5999@nowhere> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=ses30wElf2fkl1OyQXXsEZJ9Tr+UZFQDaA8XQm0X87A=; b=d0C5VIrWTfShtX/RpBRHDQNVORSKpjI3IVJFZ2ZO7022wRiifckeAacpyccADbPGgQ 010x1/a/1ryzkGiR+uG99taYA8D587fT2scj85/LCXTZhp5izvJHCpZO8SrSdl3TOSrl YVPrhLlgJHRu26Bfqpc4VPt6RraPLnSgPdP6M= In-Reply-To: <20100909015346.GA5999@nowhere> Sender: reiserfs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Frederic Weisbecker Cc: Andrew Morton , linux-kernel@vger.kernel.org, reiserfs-devel@vger.kernel.org, Christoph Hellwig , Al Viro Frederic Weisbecker wrote, On 12/23/-28158 08:59 PM: > On Wed, Sep 08, 2010 at 03:37:30PM -0700, Andrew Morton wrote: >> On Sun, 5 Sep 2010 13:31:21 +0200 >> Jarek Poplawski wrote: >> >>> Hi, >>> I get this warning on every lilo write with 2.6.35.4 and a bit/git >>> later too. >>> >> Can you tell us the latest kernel version which did *not* have this >> bug? That way we can narrow the problem down a bit. >> >> Thanks. > > > > Ah, when you see &REISERFS_SB(s)->lock in a bug report, don't hesitate to blame me :-) > > This is a problem resulting from the bkl conversion to a mutex that introduced > a lot of new locking dependencies. Most of them have been fixed, but for less > tested paths like ioctl, we hear about it later. > > Does the following patch fixes the issue? > If so, I'll make a proper changelog and put the appropriate 2.6.33-35 stable > tags for the backport. > > Thnaks! > > > diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c > index f53505d..679d502 100644 > --- a/fs/reiserfs/ioctl.c > +++ b/fs/reiserfs/ioctl.c > @@ -188,7 +188,7 @@ int reiserfs_unpack(struct inode *inode, struct file *filp) > /* we need to make sure nobody is changing the file size beneath > ** us > */ > - mutex_lock(&inode->i_mutex); > + reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb); > reiserfs_write_lock(inode->i_sb); > > write_from = inode->i_size & (blocksize - 1); > So, there is still a warning but a bit different now. Jarek P. [ 67.110273] ======================================================= [ 67.110313] [ INFO: possible circular locking dependency detected ] [ 67.110313] 2.6.35.4.4a #3 [ 67.110313] ------------------------------------------------------- [ 67.110313] lilo/1620 is trying to acquire lock: [ 67.110313] (&journal->j_mutex){+.+...}, at: [] do_journal_begin_r+0x7f/0x340 [reiserfs] [ 67.110313] [ 67.110313] but task is already holding lock: [ 67.110313] (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x28/0x40 [reiserfs] [ 67.110313] [ 67.110313] which lock already depends on the new lock. [ 67.110313] [ 67.110313] [ 67.110313] the existing dependency chain (in reverse order) is: [ 67.110313] [ 67.110313] -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [ 67.110313] [] lock_acquire+0x67/0x80 [ 67.110313] [] __mutex_lock_common+0x4d/0x410 [ 67.110313] [] mutex_lock_nested+0x18/0x20 [ 67.110313] [] reiserfs_write_lock+0x28/0x40 [reiserfs] [ 67.110313] [] do_journal_begin_r+0x86/0x340 [reiserfs] [ 67.110313] [] journal_begin+0x77/0x140 [reiserfs] [ 67.110313] [] reiserfs_remount+0x224/0x530 [reiserfs] [ 67.110313] [] do_remount_sb+0x60/0x110 [ 67.110313] [] do_mount+0x625/0x790 [ 67.110313] [] sys_mount+0x84/0xb0 [ 67.110313] [] syscall_call+0x7/0xb [ 67.110313] [ 67.110313] -> #0 (&journal->j_mutex){+.+...}: [ 67.110313] [] __lock_acquire+0x1026/0x1180 [ 67.110313] [] lock_acquire+0x67/0x80 [ 67.110313] [] __mutex_lock_common+0x4d/0x410 [ 67.110313] [] mutex_lock_nested+0x18/0x20 [ 67.110313] [] do_journal_begin_r+0x7f/0x340 [reiserfs] [ 67.110313] [] journal_begin+0x77/0x140 [reiserfs] [ 67.110313] [] reiserfs_persistent_transaction+0x41/0x90 [reiserfs] [ 67.110313] [] reiserfs_get_block+0x22c/0x1530 [reiserfs] [ 67.110313] [] __block_prepare_write+0x1bb/0x3a0 [ 67.110313] [] block_prepare_write+0x26/0x40 [ 67.110313] [] reiserfs_prepare_write+0x88/0x170 [reiserfs] [ 67.110313] [] reiserfs_unpack+0xe6/0x120 [reiserfs] [ 67.110313] [] reiserfs_ioctl+0x272/0x320 [reiserfs] [ 67.110313] [] vfs_ioctl+0x28/0xa0 [ 67.110313] [] do_vfs_ioctl+0x32d/0x5c0 [ 67.110313] [] sys_ioctl+0x63/0x70 [ 67.110313] [] syscall_call+0x7/0xb [ 67.110313] [ 67.110313] other info that might help us debug this: [ 67.110313] [ 67.110313] 2 locks held by lilo/1620: [ 67.110313] #0: (&sb->s_type->i_mutex_key#8){+.+.+.}, at: [] reiserfs_unpack+0x6a/0x120 [reiserfs] [ 67.110313] #1: (&REISERFS_SB(s)->lock){+.+.+.}, at: [] reiserfs_write_lock+0x28/0x40 [reiserfs] [ 67.110313] [ 67.110313] stack backtrace: [ 67.110313] Pid: 1620, comm: lilo Not tainted 2.6.35.4.4a #3 [ 67.110313] Call Trace: [ 67.110313] [] ? printk+0x18/0x1e [ 67.110313] [] print_circular_bug+0xd2/0xe0 [ 67.110313] [] __lock_acquire+0x1026/0x1180 [ 67.110313] [] lock_acquire+0x67/0x80 [ 67.110313] [] ? do_journal_begin_r+0x7f/0x340 [reiserfs] [ 67.110313] [] __mutex_lock_common+0x4d/0x410 [ 67.110313] [] ? do_journal_begin_r+0x7f/0x340 [reiserfs] [ 67.110313] [] ? __lock_acquire+0x1a5/0x1180 [ 67.110313] [] ? mempool_alloc_slab+0xe/0x10 [ 67.110313] [] mutex_lock_nested+0x18/0x20 [ 67.110313] [] ? do_journal_begin_r+0x7f/0x340 [reiserfs] [ 67.110313] [] do_journal_begin_r+0x7f/0x340 [reiserfs] [ 67.110313] [] ? mark_held_locks+0x62/0x80 [ 67.110313] [] ? kmem_cache_alloc+0x7d/0xb0 [ 67.110313] [] ? trace_hardirqs_on_caller+0x11c/0x160 [ 67.110313] [] journal_begin+0x77/0x140 [reiserfs] [ 67.110313] [] ? reiserfs_persistent_transaction+0x32/0x90 [reiserfs] [ 67.110313] [] reiserfs_persistent_transaction+0x41/0x90 [reiserfs] [ 67.110313] [] reiserfs_get_block+0x22c/0x1530 [reiserfs] [ 67.110313] [] ? __lock_acquire+0x1a5/0x1180 [ 67.110313] [] ? _raw_spin_unlock_irq+0x22/0x50 [ 67.110313] [] ? kmem_cache_alloc+0x7d/0xb0 [ 67.110313] [] ? trace_hardirqs_on_caller+0x11c/0x160 [ 67.110313] [] ? sub_preempt_count+0x7b/0xb0 [ 67.110313] [] ? _raw_spin_unlock+0x27/0x40 [ 67.110313] [] __block_prepare_write+0x1bb/0x3a0 [ 67.110313] [] block_prepare_write+0x26/0x40 [ 67.110313] [] ? reiserfs_get_block+0x0/0x1530 [reiserfs] [ 67.110313] [] reiserfs_prepare_write+0x88/0x170 [reiserfs] [ 67.110313] [] ? reiserfs_get_block+0x0/0x1530 [reiserfs] [ 67.110313] [] reiserfs_unpack+0xe6/0x120 [reiserfs] [ 67.110313] [] reiserfs_ioctl+0x272/0x320 [reiserfs] [ 67.110313] [] ? reiserfs_ioctl+0x0/0x320 [reiserfs] [ 67.110313] [] vfs_ioctl+0x28/0xa0 [ 67.110313] [] do_vfs_ioctl+0x32d/0x5c0 [ 67.110313] [] ? might_fault+0x88/0x90 [ 67.110313] [] ? might_fault+0x42/0x90 [ 67.110313] [] ? fget_light+0xf8/0x2f0 [ 67.110313] [] sys_ioctl+0x63/0x70 [ 67.110313] [] syscall_call+0x7/0xb [ 67.110313] [] ? cookie_v6_check+0x44b/0x630