From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from waste.org ([173.11.57.241]) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1Na0Ee-0006yq-RU for linux-mtd@lists.infradead.org; Wed, 27 Jan 2010 05:14:41 +0000 Subject: Re: UBIFS assert failed in ubifs_dirty_inode From: Matt Mackall To: dedekind1@gmail.com In-Reply-To: <1264566010.2401.143.camel@localhost.localdomain> References: <4B591573.60602@theptrgroup.com> <1264480808.2401.78.camel@localhost.localdomain> <1264484928.3536.1017.camel@calx> <1264500214.3867.21.camel@localhost> <4B5F9A78.7080000@theptrgroup.com> <1264558433.3536.1543.camel@calx> <4B5FADE8.30803@theptrgroup.com> <1264566010.2401.143.camel@localhost.localdomain> Content-Type: text/plain; charset="UTF-8" Date: Tue, 26 Jan 2010 23:14:26 -0600 Message-ID: <1264569266.3536.1547.camel@calx> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Cc: Jeff Angielski , linux-mtd@lists.infradead.org, Herbert Xu , LKML List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2010-01-27 at 06:20 +0200, Artem Bityutskiy wrote: > On Tue, 2010-01-26 at 22:07 -0500, Jeff Angielski wrote: > > Matt Mackall wrote: > > > On Tue, 2010-01-26 at 20:44 -0500, Jeff Angielski wrote: > > >> Artem Bityutskiy wrote: > > >>> On Mon, 2010-01-25 at 23:48 -0600, Matt Mackall wrote: > > >>>> Hmm. I'd just as soon drop it entirely. Here's a patch. Herbert, you > > >>>> want to send this through your crypto tree? > > >>>> > > >>>> > > >>>> random: drop weird m_time/a_time manipulation > > >>>> > > >>>> No other driver does anything remotely like this that I know of except > > >>>> for the tty drivers, and I can't see any reason for random/urandom to do > > >>>> it. In fact, it's a (trivial, harmless) timing information leak. And > > >>>> obviously, it generates power- and flash-cycle wasting I/O, especially > > >>>> if combined with something like hwrngd. Also, it breaks ubifs's > > >>>> expectations. > > >>>> > > >>>> Signed-off-by: Matt Mackall > > >>>> > > >>>> diff -r 29db0c391ce8 drivers/char/random.c > > >>>> --- a/drivers/char/random.c Sun Jan 17 11:01:16 2010 -0800 > > >>>> +++ b/drivers/char/random.c Mon Jan 25 23:32:00 2010 -0600 > > >>>> @@ -1051,12 +1051,6 @@ > > >>>> /* like a named pipe */ > > >>>> } > > >>>> > > >>>> - /* > > >>>> - * If we gave the user some bytes, update the access time. > > >>>> - */ > > >>>> - if (count) > > >>>> - file_accessed(file); > > >>>> - > > >>>> return (count ? count : retval); > > >>>> } > > >>>> > > >>>> @@ -1116,8 +1110,6 @@ > > >>>> if (ret) > > >>>> return ret; > > >>>> > > >>>> - inode->i_mtime = current_fs_time(inode->i_sb); > > >>>> - mark_inode_dirty(inode); > > >>>> return (ssize_t)count; > > >>>> } > > >>> It may brake other FSes expectations, theoretically, as well. > > >>> > > >>> Anyway, I'm perfectly fine if this is removed. > > >>> > > >>> Jeff, could you please try Matt's patch and report back if you still > > >>> have issues or not. If no, you can use this as a temporary work-around > > >>> until a proper fix hits upstream or ubifs-2.6.git. > > >> Matt's patch did not compile as written. I tried to implement what I > > >> think he was trying to do and created this patch (it seems to match the > > >> guts of what inode_setattr() was looking for): > > >> > > >> > > >> diff --git a/drivers/char/random.c b/drivers/char/random.c > > >> index 8258982..70f16c7 100644 > > >> --- a/drivers/char/random.c > > >> +++ b/drivers/char/random.c > > >> @@ -1108,6 +1108,7 @@ static ssize_t random_write(struct file *file, > > >> const char __user *buffer, > > >> { > > >> size_t ret; > > >> struct inode *inode = file->f_path.dentry->d_inode; > > >> + struct iattr attr; > > >> > > >> ret = write_pool(&blocking_pool, buffer, count); > > >> if (ret) > > >> @@ -1116,8 +1117,12 @@ static ssize_t random_write(struct file *file, > > >> const char __user *buffer, > > >> if (ret) > > >> return ret; > > >> > > >> - inode->i_mtime = current_fs_time(inode->i_sb); > > >> - mark_inode_dirty(inode); > > >> + attr.ia_mtime = current_fs_time(inode->i_sb); > > >> + attr.ia_valid = ATTR_MTIME; > > >> + ret = inode_setattr(inode, &attr); > > >> + if (ret) > > >> + return ret; > > >> + > > >> return (ssize_t)count; > > >> } > > >> > > >> However, this patch does not fix the problem. I still see the same > > >> errors. Matt, is this what you were trying to do? > > > > > > That doesn't look anything like my patch? And mine was test compiled. > > > > Ahh, you would be right. I mixed up authors. My bad. ;) > > > > Matt's patch that removes the offending code works fine. > > > > Artem's patch that tries to fix the offending code (and does not compile > > as posted) does not work. > > Thanks for testing. So, who would bring Matt's patch upstream then, hmm? > I think Herbert's tree is the best path, but if he doesn't chime in, I'll send it through Andrew. -- http://selenic.com : development and support for Mercurial and Linux