From: Al Viro <viro@zeniv.linux.org.uk>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
Yonghong Song <yhs@fb.com>, Martin KaFai Lau <kafai@fb.com>,
David Miller <davem@redhat.com>,
John Fastabend <john.fastabend@gmail.com>,
Jesper Dangaard Brouer <hawk@kernel.org>,
Wenbo Zhang <ethercflow@gmail.com>,
KP Singh <kpsingh@chromium.org>, Andrii Nakryiko <andriin@fb.com>,
bgregg@netflix.com
Subject: Re: [RFC 0/3] bpf: Add d_path helper
Date: Mon, 6 Apr 2020 04:16:02 +0100 [thread overview]
Message-ID: <20200406031602.GR23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200403090828.GF2784502@krava>
On Fri, Apr 03, 2020 at 11:08:28AM +0200, Jiri Olsa wrote:
> if we limit it just to task context I think it would still be
> helpful for us:
>
> if (in_task())
> d_path..
>
> perhaps even create a d_path version without d_dname callback
> if that'd be still a problem, because it seems to be there mainly
> for special filesystems..?
IDGI...
1) d_path(), by definition, is dependent upon the
process' root - the same <mount,dentry> pair will yield
different strings if caller is chrooted. You *can't* just
use a random process' root
2) we are *NOT* making rename_lock and mount_lock
disable interrupts. Not happening.
So it has to be process-synchronous anyway. Could you describe
where that thing is going to be callable?
next prev parent reply other threads:[~2020-04-06 3:16 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-01 11:09 [RFC 0/3] bpf: Add d_path helper Jiri Olsa
2020-04-01 11:09 ` [PATCH 1/3] bpf: Add support to check if BTF object is nested in another object Jiri Olsa
2020-04-07 1:16 ` Alexei Starovoitov
2020-04-07 9:37 ` Jiri Olsa
2020-04-01 11:09 ` [PATCH 2/3] bpf: Add d_path helper Jiri Olsa
2020-04-02 14:02 ` Florent Revest
2020-04-03 9:01 ` Jiri Olsa
2020-04-06 2:49 ` Andrii Nakryiko
2020-04-01 11:09 ` [PATCH 3/3] selftests/bpf: Add test for " Jiri Olsa
2020-04-02 14:03 ` [RFC 0/3] bpf: Add " Florent Revest
2020-04-03 8:55 ` Jiri Olsa
2020-04-02 14:21 ` Al Viro
2020-04-03 9:08 ` Jiri Olsa
2020-04-06 3:16 ` Al Viro [this message]
2020-04-06 9:09 ` Jiri Olsa
2020-04-06 12:47 ` Al Viro
2020-04-07 1:10 ` Alexei Starovoitov
2020-04-07 8:53 ` Jiri Olsa
2020-04-07 9:27 ` KP Singh
2020-04-07 9:45 ` Jiri Olsa
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