Re: [PATCH v4] 9p: retrieve fid from file when file instance exist.

From: Dominique Martinet
Date: Fri Jul 10 2020 - 07:09:09 EST


Jianyong Wu wrote on Fri, Jul 10, 2020:
> In the current setattr implementation in 9p, fid is always retrieved
> from dentry no matter file instance exists or not. If so, there may be
> some info related to opened file instance dropped. So it's better
> to retrieve fid from file instance when it is passed to setattr.
>
> for example:
> fd=open("tmp", O_RDWR);
> ftruncate(fd, 10);
>
> The file context related with the fd will be lost as fid is always
> retrieved from dentry, then the backend can't get the info of
> file context. It is against the original intention of user and
> may lead to bug.
>
> Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
> ---


For next time, you can add arbitrary comments (e.g. describe briefly
differences from previous versions) after the --- line.

For others, this inits fid to NULL in both functions; thanks for picking
it up I'll refresh the patch.

--
Dominique