On Thu, Mar 31, 2022 at 01:23:17PM +0200, Christian Brauner wrote:
> Now that overlay is able to take a layers idmapping into account allow
> overlay mounts to be created on top of idmapped mounts.
>
> Cc: <linux-unionfs@xxxxxxxxxxxxxxx>
> Tested-by: Giuseppe Scrivano <gscrivan@xxxxxxxxxx>
> Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
> ---
> /* v2 */
> - Turn on support for idmapped mounts in ovl_upper_idmap() helper here
> after we've introduced it earlier in the series and made it return the
> initial idmapping.
>
> /* v3 */
> unchanged
> ---
> fs/overlayfs/ovl_entry.h | 2 +-
> fs/overlayfs/super.c | 4 ----
> 2 files changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
> index 79b612cfbe52..898b002a5c6f 100644
> --- a/fs/overlayfs/ovl_entry.h
> +++ b/fs/overlayfs/ovl_entry.h
> @@ -92,7 +92,7 @@ static inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs)
>
> static inline struct user_namespace *ovl_upper_idmap(struct ovl_fs *ofs)
Same minor nit here. Will ovl_upper_mnt_userns() be better for
readability. If it is too long, may be ovl_upper_mnt_uns().
I have this general comment here and other places
where "idmap" has been used. "idmap" is just one property vfs
derives from user namespace associated with mnt.
Vivek
> {
> - return &init_user_ns;
> + return mnt_user_ns(ovl_upper_mnt(ofs));
> }
>
> static inline struct ovl_fs *OVL_FS(struct super_block *sb)
> diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
> index 9a656a24f7b1..d4cc07f7a2ef 100644
> --- a/fs/overlayfs/super.c
> +++ b/fs/overlayfs/super.c
> @@ -874,10 +874,6 @@ static int ovl_mount_dir_noesc(const char *name, struct path *path)
> pr_err("filesystem on '%s' not supported\n", name);
> goto out_put;
> }
> - if (is_idmapped_mnt(path->mnt)) {
> - pr_err("idmapped layers are currently not supported\n");
> - goto out_put;
> - }
> if (!d_is_dir(path->dentry)) {
> pr_err("'%s' not a directory\n", name);
> goto out_put;
> --
> 2.32.0
>
