From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: Regression in next with ext4 oops Date: Tue, 4 Oct 2016 12:29:09 -0700 Message-ID: <20161004192908.sl6iabbgkyyrdhes@atomide.com> References: <20161003233054.eltv3coiweht3ui4@atomide.com> <20161004090041.GE17515@quack2.suse.cz> <20161004140231.fyfrc6rs2lb6z63v@thunk.org> <20161004145915.GZ19539@ZenIV.linux.org.uk> <20161004191633.muirbg7mvb3ylhhl@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20161004191633.muirbg7mvb3ylhhl@atomide.com> Sender: linux-kernel-owner@vger.kernel.org To: Al Viro Cc: Theodore Ts'o , Jan Kara , Eric Biggers , Andreas Dilger , Jaegeuk Kim , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Kalle Valo List-Id: linux-omap@vger.kernel.org * Tony Lindgren [161004 12:17]: > Hi, > > * Al Viro [161004 08:00]: > > On Tue, Oct 04, 2016 at 10:02:31AM -0400, Theodore Ts'o wrote: > > > On Tue, Oct 04, 2016 at 11:00:41AM +0200, Jan Kara wrote: > > > > Never seen this but I suspect it is a fallout from Al's directory locking > > > > changes. In particular ext4_htree_fill_tree() builds rb-tree of found > > > > directory entries in file->private_data (and generally modifies the > > > > structure stored there) but after Al's changes we don't have exclusive > > > > access to struct file if I'm right so if two processes end up calling > > > > getdents() for the same 'struct file' we are doomed. > > > > > > I haven't seen it either, and I've been doing a lot of testing on the > > > ext4 test branch. So I'm guessing Tony has the only reliable repro > > > for the problem at the moment. That being said, it shouldn't be that > > > hard to create a test case for this and add it to xfstests. > > > > > > I'm pretty sure Jan is right about this, though, but it would be great > > > to a get a quick confirmation from Tony if at all possible. > > > > Jan is wrong - we do have per-struct-file serialization for getdents() > > et.al. It might be a race between getdents() on *different* struct > > file for the same directory, but ->private_data is not a problem. > > OK found the guilty person after git bisect and that's me. > > Git bisect points to commit d776fc86b82f ("wlcore: sdio: Populate config > firmware data"), so adding Kalle to Cc. > > Looks like update-initramfs does rmmod of wlcore_sdio and that triggers > some issue with the wlcore driver or with SDIO/MMC. Or maybe it's a memory > corruption issue. I don't know yet exactly what's going on here yet but > I plan to find out after some lunch. And the patch below seems to fix the issue as the driver is now using devm_kzalloc. Will do some more testing and then will post a proper patch. The same issue might be there for SPI glue also. Regards, Tony 8< ----------------- --- a/drivers/net/wireless/ti/wlcore/sdio.c +++ b/drivers/net/wireless/ti/wlcore/sdio.c @@ -391,7 +391,6 @@ static void wl1271_remove(struct sdio_func *func) pm_runtime_get_noresume(&func->dev); platform_device_unregister(glue->core); - kfree(glue); } #ifdef CONFIG_PM