On Tue, 2024-03-19 at 18:47 +0800, Chen Hanxiao wrote:
> As write_filehandle can't accept zero-bytes writting,
> remove read permission of /proc/fs/nfsd/filehandle
>
> Signed-off-by: Chen Hanxiao <chenhx.fnst@xxxxxxxxxxx>
> ---
> fs/nfsd/nfsctl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index ecd18bffeebc..da1387f1e30a 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -1346,7 +1346,7 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc)
> &transaction_ops, S_IWUSR|S_IRUSR},
> [NFSD_FO_UnlockFS] = {"unlock_filesystem",
> &transaction_ops, S_IWUSR|S_IRUSR},
> - [NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
> + [NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR},
> [NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
> [NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
> [NFSD_Pool_Stats] = {"pool_stats", &pool_stats_operations, S_IRUGO},
I don't think we can do this. mountd does this to get the rootfh for an
exported fs and it'll probably start failing if it can't open that file
for read:
f = open("/proc/fs/nfsd/filehandle", O_RDWR);
That write_filehandle interface sure is weird though. Could we get rid
of it by teaching cache_get_filehandle how to use name_to_handle_at
instead? That would be a lot cleaner and would get rid of yet another
dependency on /proc/fs/nfsd.
--
Jeff Layton <jlayton@xxxxxxxxxx>
