From: Tyler Hicks <tyhicks@linux.microsoft.com>
To: Dominique Martinet <asmadeus@codewreck.org>
Cc: Christian Schoenebeck <linux_oss@crudebyte.com>,
Eric Van Hensbergen <ericvh@gmail.com>,
Latchesar Ionkov <lucho@ionkov.net>,
v9fs-developer@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 06/06] 9p fid refcount: cleanup p9_fid_put calls
Date: Mon, 13 Jun 2022 15:12:41 -0500 [thread overview]
Message-ID: <20220613201241.GH7401@sequoia> (raw)
In-Reply-To: <YqeVFTkREfWUfPFi@codewreck.org>
On 2022-06-14 04:50:45, Dominique Martinet wrote:
> Thanks for the reviews,
>
> Tyler Hicks wrote on Mon, Jun 13, 2022 at 12:55:09PM -0500:
> > > @@ -189,13 +197,13 @@ static struct p9_fid *v9fs_fid_lookup_with_uid(struct dentry *dentry,
> > > else
> > > uname = v9ses->uname;
> > >
> > > - root_fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
> > > - v9ses->aname);
> > > - if (IS_ERR(root_fid))
> > > - return root_fid;
> > > + fid = p9_client_attach(v9ses->clnt, NULL, uname, uid,
> >
> > To keep the readability benefits in my "9p: Track the root fid with its
> > own variable during lookups" patch, I think root_fid should be assigned
> > here and then used in the error check and return statement.
> >
> > > + v9ses->aname);
> > > + if (IS_ERR(fid))
> > > + return fid;
> > >
> > > - p9_fid_get(root_fid);
> > > - v9fs_fid_add(dentry->d_sb->s_root, root_fid);
> > > + root_fid = p9_fid_get(fid);
> > > + v9fs_fid_add(dentry->d_sb->s_root, &fid);
> >
> > root_fid should be used in the two lines above, too.
>
> This actually was the only place where we still want to use the root_fid
> after calling v9fs_fid_add; if we keep root_fid above we need to do
> something like
>
> fid = p9_fid_get(root_fid);
> v9fs_Fid_add(dentry->d_sb->s_root, &root_fid);
> root_fid = fid;
> // fid = NULL; ? not strictly needed as we set it again shortly afterwards
>
> which I wanted to avoid, but I guess I don't mind strongly either way --
> pick your poison.
Ah, very good point. I missed that subtly.
> I could also just keep v9fs_fid_add as a non-stealing version, but I
> think it's better that way as it strongly signal that we stashed that
> ref away and shouldn't use the fid anymore unless another ref was
> obtained through fid_get like we do here.
> (I was actually tempted to do the same with p9_fid_put, but checking
> other kernel "put"s I didn't see any code that does this so I refrained
> from that churn)
I like the stealing version. Lets go with it and keep this patch as-is.
Please feel free to slap this tag on it:
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Tyler
>
> --
> Dominique
>
next prev parent reply other threads:[~2022-06-13 20:54 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-12 8:53 [PATCH 00/06] fid refcounting improvements and fixes Dominique Martinet
2022-06-12 8:53 ` [PATCH 01/06] 9p: fix fid refcount leak in v9fs_vfs_atomic_open_dotl Dominique Martinet
2022-06-13 16:27 ` Tyler Hicks
2022-06-14 13:17 ` Christian Schoenebeck
2022-06-12 8:53 ` [PATCH 02/06] 9p: fix fid refcount leak in v9fs_vfs_get_link Dominique Martinet
2022-06-13 16:29 ` Tyler Hicks
2022-06-14 13:19 ` Christian Schoenebeck
2022-06-12 8:53 ` [PATCH 03/06] 9p: v9fs_fid_lookup_with_uid fix's fix suggestion Dominique Martinet
2022-06-13 20:08 ` Tyler Hicks
2022-06-12 8:53 ` [PATCH 04/06] 9p fid refcount: add p9_fid_get/put wrappers Dominique Martinet
2022-06-12 23:45 ` [PATCH v2 " Dominique Martinet
2022-06-13 17:31 ` Tyler Hicks
2022-06-14 13:55 ` Christian Schoenebeck
2022-06-14 14:27 ` Dominique Martinet
2022-06-15 3:16 ` [PATCH v3 " Dominique Martinet
2022-06-15 13:00 ` Christian Schoenebeck
2022-06-15 13:47 ` Dominique Martinet
2022-06-12 8:53 ` [PATCH 05/06] 9p fid refcount: add a 9p_fid_ref tracepoint Dominique Martinet
2022-06-12 22:46 ` Steven Rostedt
2022-06-12 23:46 ` [PATCH v2 " Dominique Martinet
2022-06-13 7:00 ` Dominique Martinet
2022-06-12 8:53 ` [PATCH 06/06] 9p fid refcount: cleanup p9_fid_put calls Dominique Martinet
2022-06-13 17:55 ` Tyler Hicks
2022-06-13 19:50 ` Dominique Martinet
2022-06-13 20:12 ` Tyler Hicks [this message]
2022-06-13 20:20 ` [PATCH 00/06] fid refcounting improvements and fixes Tyler Hicks
2022-06-13 21:00 ` Dominique Martinet
2022-06-14 1:14 ` Tyler Hicks
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