On Dec 10 2018, Miklos Szeredi <miklos@xxxxxxxxxx> wrote:
> On Tue, Dec 4, 2018 at 8:02 PM Nikolaus Rath <Nikolaus@xxxxxxxx> wrote:
>>
>> On Dec 04 2018, Miklos Szeredi <mszeredi@xxxxxxxxxx> wrote:
>> > On Tue, Dec 4, 2018 at 10:03 AM Nikolaus Rath <Nikolaus@xxxxxxxx> wrote:
>> >>
>> >> Hi,
>> >>
>> >> Really no one any suggestion for debugging this?
>> >>
>> >> (Adding some more people who recently worked on fs/fuse)
>> >>
>> >> Best,
>> >> -Nikolaus
>> >>
>> >> On Nov 27 2018, Nikolaus Rath <Nikolaus@xxxxxxxx> wrote:
>> >> > Hi,
>> >> >
>> >> > When testing FUSE under heavy load, I am occasionally getting EBADFD
>> >> > errors when reading from the fuse pipe.
>> >
>> > EBADFD or EBADF?
>>
>> EBADF ("Bad file descriptor"), sorry.
>
> Can you run the thing with "strace -f ..."?
Apologies for the delayed response. I have been trying to reproduce this
but have instead run into another problem: the *client* getting spurious
EBADF warnings. I am not sure if this is related or unrelated, and it
has been hard to debug because it does not happen under strace:
$ find mnt > /dev/null
find: ‘mnt/modules/4.18.0-0.bpo.3-amd64/kernel/net/8021q’: Bad file descriptor
find: ‘mnt/modules/4.18.0-0.bpo.3-amd64/kernel/drivers/net/ethernet/natsemi’: Bad file descriptor
This happens in roughly 1 in 2 runs, and the affected directory entries
are always different. Disabling readdirplus does not make a difference.
$ strace -o log find mnt > /dev/null
never gave in error in roughly 20 attempts.
Similarly, enabling fuse debug logging also makes the problem go away.
I also found some odd warnings in dmesg:
[24472.435256] fuse: trying to steal weird page
[24472.435261] page=00000000b5b89670 index=0 flags=17fffc0000000ad, count=1, mapcount=0, map
..happens a lot (and I just wrote another email about it), and
[24473.170110] VFS: Lookup of '4.18.0-0.bpo.1-amd64' in fuse fuse would have caused loop
happened only a few times (and the `fuse` string is indeed
duplicated). When this happens, `find` complains that:
$ find mnt > /dev/null
find: File system loop detected; ‘mnt/modules/4.18.0-0.bpo.1-amd64/kernel/drivers/w1’ is part of the same file system loop as ‘mnt/modules’
Does this ring any bells with anyone?
Best,
-Nikolaus
--
GPG Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F
»Time flies like an arrow, fruit flies like a Banana.«
