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charset="UTF-8" X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 2C0F518000C X-Stat-Signature: 7ajmuhp5yu1ikxpawwomiyg5ckqqqjtn Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=kfqxIL1G; dmarc=pass (policy=none) header.from=bytedance.com; spf=pass (imf06.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.128.177 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com X-Rspam-User: X-HE-Tag: 1648111496-739420 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 24, 2022 at 11:05 AM Linus Torvalds wrote: > > On Wed, Mar 23, 2022 at 7:19 PM Muchun Song wrote: > > > > After this commit, the rules of dentry allocations changed. > > The dentry should be allocated by kmem_cache_alloc_lru() > > Yeah, I looked at that, but I can't find any way there could be other > allocations - not only are there strict rules how to initialize > everything, but the dentries are free'd using > > kmem_cache_free(dentry_cache, dentry); > > and as a result if they were allocated any other way I would expect > things would go south very quickly. > > The only other thing I could come up with is some breakage in the > superblock lifetime so that &dentry->d_sb->s_dentry_lru would have > problems, but again, this is *such* core code and not some unusual > path, that I would be very very surprised if it wouldn't have > triggered other issues long long ago. > > That's why I'd be more inclined to worry about the list_lru code being > somehow broken. > I also have the same concern. I have been trying for a few hours to reproduce this issue, but it didn't oops on my test machine. And I'll continue reproducing this. Thanks.