Re: [PATCH 1/4] ovl: support [S|G]ETFLAGS ioctl for directories

[Amir Goldstein <amir73il@gmail.com>]

On Mon, Jul 15, 2019 at 4:38 PM Amir Goldstein <amir73il@gmail.com> wrote:
>
> [S|G]ETFLAGS and FS[S|G]ETXATTR ioctls are applicable to both files and
> directories, so add ioctl operations to dir as well.
>
> ifdef away compat ioctl implementation to conform to standard practice.
>
> With this change, xfstest generic/079 which tests these ioctls on files
> and directories passes.
>
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
>  fs/overlayfs/file.c      | 10 ++++++----
>  fs/overlayfs/overlayfs.h |  2 ++
>  fs/overlayfs/readdir.c   |  4 ++++
>  3 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
> index e235a635d9ec..c6426e4d3f1f 100644
> --- a/fs/overlayfs/file.c
> +++ b/fs/overlayfs/file.c
> @@ -502,7 +502,7 @@ static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd,
>                                    ovl_fsxflags_to_iflags(fa.fsx_xflags));
>  }
>
> -static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  {
>         long ret;
>
> @@ -527,8 +527,8 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>         return ret;
>  }
>
> -static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
> -                            unsigned long arg)
> +#ifdef CONFIG_COMPAT
> +long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  {
>         switch (cmd) {
>         case FS_IOC32_GETFLAGS:
> @@ -545,6 +545,7 @@ static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
>
>         return ovl_ioctl(file, cmd, arg);
>  }
> +#endif
>
>  enum ovl_copyop {
>         OVL_COPY,
> @@ -646,8 +647,9 @@ const struct file_operations ovl_file_operations = {
>         .fallocate      = ovl_fallocate,
>         .fadvise        = ovl_fadvise,
>         .unlocked_ioctl = ovl_ioctl,
> +#ifdef CONFIG_COMPAT
>         .compat_ioctl   = ovl_compat_ioctl,
> -
> +#endif
>         .copy_file_range        = ovl_copy_file_range,
>         .remap_file_range       = ovl_remap_file_range,
>  };
> diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
> index 6934bcf030f0..7c94cc3521cb 100644
> --- a/fs/overlayfs/overlayfs.h
> +++ b/fs/overlayfs/overlayfs.h
> @@ -416,6 +416,8 @@ struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
>
>  /* file.c */
>  extern const struct file_operations ovl_file_operations;
> +long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
> +long ovl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
>
>  /* copy_up.c */
>  int ovl_copy_up(struct dentry *dentry);
> diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
> index 47a91c9733a5..eff8fbfccc7c 100644
> --- a/fs/overlayfs/readdir.c
> +++ b/fs/overlayfs/readdir.c
> @@ -907,6 +907,10 @@ const struct file_operations ovl_dir_operations = {
>         .llseek         = ovl_dir_llseek,
>         .fsync          = ovl_dir_fsync,
>         .release        = ovl_dir_release,
> +       .unlocked_ioctl = ovl_ioctl,
> +#ifdef CONFIG_COMPAT
> +       .compat_ioctl   = ovl_compat_ioctl,
> +#endif
>  };
>

Big self NACK!!!

Cannot call ovl_ioctl => ovl_real_ioctl => ovl_real_fdget with a directory.
If we do this need to implement ovl_dir_ioctl and refactor the ioctl helpers.

Sorry,
Amir.