From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: Re: [BUG] fs/f2fs: a possible sleep-in-atomic bug in f2fs_trace_pid Date: Tue, 12 Dec 2017 10:00:54 +0800 Message-ID: <9272d87c-ef9b-a19d-ffe1-1db2b8785d74@huawei.com> References: <8e7328d3-2df3-e79d-9558-a9b3713751c4@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <8e7328d3-2df3-e79d-9558-a9b3713751c4@gmail.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Jia-Ju Bai , jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, Linux Kernel Mailing List List-Id: linux-f2fs-devel.lists.sourceforge.net Hi Jia-Ju, Thanks for your report. :) On 2017/12/12 8:59, Jia-Ju Bai wrote: > According to fs/f2fs/trace.c, the kernel module may sleep under a spinlock. > The function call path is: > f2fs_trace_pid (acquire the spinlock) > f2fs_radix_tree_insert > cond_resched --> may sleep > > I do not find a good way to fix it, so I only report. > This possible bug is found by my static analysis tool (DSAC) and my code > review. That's a known issue, and there are other problems in IO trace related codes, so I want to refactor the code directly, you could check the code in below link: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/commit/?h=f2fs-dev&id=d895154be1733e2bd29c9e64b57e4e201f0e8a0c But the patch still needs debugging so far. Since the IO trace feature is off by default, I expect the impaction is limited, so I pend the debug job on this patch. Anyway, I think this issue you reported should be fixed first, let me make the fixing part independent from original patch for fixing. Thanks, > > > Thanks, > Jia-Ju Bai > >