Messages in this thread | | | Date | Mon, 13 Jun 2022 15:12:41 -0500 | From | Tyler Hicks <> | Subject | Re: [PATCH 06/06] 9p fid refcount: cleanup p9_fid_put calls |
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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 >
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