Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 22 May 2019 15:02:47 -0700
From:      Conrad Meyer <cem@freebsd.org>
To:        Johannes Lundberg <johalun@freebsd.org>
Cc:        FreeBSD Current <freebsd-current@freebsd.org>
Subject:   Re: Weirdness when writing to pseudofs file
Message-ID:  <CAG6CVpVwsczJSQjqTMZz2SoPpUxC7O4QkRJ6tfVsmcp%2BHqVYrA@mail.gmail.com>
In-Reply-To: <f1e31c0b-9383-05f9-f1b5-939a586d21d0@FreeBSD.org>
References:  <6ec62e4d-9f93-ffe1-646c-3846c9308334@FreeBSD.org> <20190522175133.GC2748@kib.kiev.ua> <84e3001b-646d-b1d9-f206-577d63f79bf1@FreeBSD.org> <CAOtMX2i63czMAWmnJik5=gEY=5r4YFhz084zJ8xoThR01POGhQ@mail.gmail.com> <eb0fd852-643d-e399-2988-92de744d6e07@FreeBSD.org> <f1e31c0b-9383-05f9-f1b5-939a586d21d0@FreeBSD.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, May 22, 2019 at 1:58 PM Johannes Lundberg <johalun@freebsd.org> wrote:
> > It seems, a single '>' will cause it to try to create the file (even
> > though it already exists) and that fails (kern_openat).
> >
> I would guess because of
>
> https://github.com/freebsd/freebsd/blob/master/sys/fs/pseudofs/pseudofs_vnops.c#L1042
>
> struct vop_vector pfs_vnodeops = {
> ...
> .vop_create = VOP_EOPNOTSUPP,
> ...
> }

kern_openat -> vn_open(_cred) should only call VOP_CREATE if namei()
cannot find the named vnode (ni_vp == NULL).  Otherwise, it should
just invoke VOP_OPEN.  This suggests there might be a lookup bug in
pfs?  Tracing VOPs as Mark suggested seems like a good next step.

Best,
Conrad



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAG6CVpVwsczJSQjqTMZz2SoPpUxC7O4QkRJ6tfVsmcp%2BHqVYrA>