Matthew Wilcox <willy@xxxxxxxxxxxxx> writes:
> On Sun, May 03, 2020 at 09:43:41AM +0100, Nikolaus Rath wrote:
>> Here's what I got:
>>
>> [ 221.277260] page:ffffec4bbd639880 refcount:1 mapcount:0 mapping:0000000000000000 index:0xd9
>> [ 221.277265] flags: 0x17ffffc0000097(locked|waiters|referenced|uptodate|lru)
>> [ 221.277269] raw: 0017ffffc0000097 ffffec4bbd62f048 ffffec4bbd619308 0000000000000000
>> [ 221.277271] raw: 00000000000000d9 0000000000000000 00000001ffffffff ffff9aec11beb000
>> [ 221.277272] page dumped because: fuse: trying to steal weird page
>> [ 221.277273] page->mem_cgroup:ffff9aec11beb000
>
> Great! Here's the condition:
>
> if (page_mapcount(page) ||
> page->mapping != NULL ||
> page_count(page) != 1 ||
> (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
> ~(1 << PG_locked |
> 1 << PG_referenced |
> 1 << PG_uptodate |
> 1 << PG_lru |
> 1 << PG_active |
> 1 << PG_reclaim))) {
>
> mapcount is 0, mapping is NULL, refcount is 1, so that's all fine.
> flags has 'waiters' set, which is not in the allowed list. I don't
> know the internals of FUSE, so I don't know why that is.
>
Hi
On the first message, Nikolaus sent the following line:
>> [ 2333.009937] fuse: page=00000000dd1750e3 index=2022240 flags=17ffffc0000097, count=1,
>> mapcount=0, mapping=00000000125079ad
It should be noted that on the second run, where we got the dump_page
log, it indeed had a null mapping, which is similar to what Nikolaus
asked on the previous thread he linked to, but looks like this wasn't
the case on at least some of the reproductions of the issue. On the
line above, the condition that triggered the warning was page->mapping
!= NULL. I don't know what to do with this information, though.
--
Gabriel Krisman Bertazi
