Re: [PATCH 03/18] ovl: stack miscattr

[Vivek Goyal <vgoyal@redhat.com>]

On Wed, Feb 03, 2021 at 01:40:57PM +0100, Miklos Szeredi wrote:
> Add stacking for the miscattr operations.
> 
> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
> ---
>  fs/overlayfs/dir.c       |  2 ++
>  fs/overlayfs/inode.c     | 43 ++++++++++++++++++++++++++++++++++++++++
>  fs/overlayfs/overlayfs.h |  2 ++
>  3 files changed, 47 insertions(+)
> 
> diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
> index 28a075b5f5b2..77c6b44f8d83 100644
> --- a/fs/overlayfs/dir.c
> +++ b/fs/overlayfs/dir.c
> @@ -1300,4 +1300,6 @@ const struct inode_operations ovl_dir_inode_operations = {
>  	.listxattr	= ovl_listxattr,
>  	.get_acl	= ovl_get_acl,
>  	.update_time	= ovl_update_time,
> +	.miscattr_get	= ovl_miscattr_get,
> +	.miscattr_set	= ovl_miscattr_set,
>  };
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index d739e14c6814..97d36d1f28c3 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -11,6 +11,7 @@
>  #include <linux/posix_acl.h>
>  #include <linux/ratelimit.h>
>  #include <linux/fiemap.h>
> +#include <linux/miscattr.h>
>  #include "overlayfs.h"
>  
>  
> @@ -495,6 +496,46 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>  	return err;
>  }
>  
> +int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma)
> +{
> +	struct inode *inode = d_inode(dentry);
> +	struct dentry *upperdentry;
> +	const struct cred *old_cred;
> +	int err;
> +
> +	err = ovl_want_write(dentry);
> +	if (err)
> +		goto out;
> +
> +	err = ovl_copy_up(dentry);
> +	if (!err) {
> +		upperdentry = ovl_dentry_upper(dentry);
> +
> +		old_cred = ovl_override_creds(inode->i_sb);
> +		/* err = security_file_ioctl(real.file, cmd, arg); */

Is this an comment intended?

Vivek

> +		err = vfs_miscattr_set(upperdentry, ma);
> +		revert_creds(old_cred);
> +		ovl_copyflags(ovl_inode_real(inode), inode);
> +	}
> +	ovl_drop_write(dentry);
> +out:
> +	return err;
> +}
> +
> +int ovl_miscattr_get(struct dentry *dentry, struct miscattr *ma)
> +{
> +	struct inode *inode = d_inode(dentry);
> +	struct dentry *realdentry = ovl_dentry_real(dentry);
> +	const struct cred *old_cred;
> +	int err;
> +
> +	old_cred = ovl_override_creds(inode->i_sb);
> +	err = vfs_miscattr_get(realdentry, ma);
> +	revert_creds(old_cred);
> +
> +	return err;
> +}
> +
>  static const struct inode_operations ovl_file_inode_operations = {
>  	.setattr	= ovl_setattr,
>  	.permission	= ovl_permission,
> @@ -503,6 +544,8 @@ static const struct inode_operations ovl_file_inode_operations = {
>  	.get_acl	= ovl_get_acl,
>  	.update_time	= ovl_update_time,
>  	.fiemap		= ovl_fiemap,
> +	.miscattr_get	= ovl_miscattr_get,
> +	.miscattr_set	= ovl_miscattr_set,
>  };
>  
>  static const struct inode_operations ovl_symlink_inode_operations = {
> diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
> index b487e48c7fd4..d3ad02c34cca 100644
> --- a/fs/overlayfs/overlayfs.h
> +++ b/fs/overlayfs/overlayfs.h
> @@ -509,6 +509,8 @@ int __init ovl_aio_request_cache_init(void);
>  void ovl_aio_request_cache_destroy(void);
>  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);
> +int ovl_miscattr_get(struct dentry *dentry, struct miscattr *ma);
> +int ovl_miscattr_set(struct dentry *dentry, struct miscattr *ma);
>  
>  /* copy_up.c */
>  int ovl_copy_up(struct dentry *dentry);
> -- 
> 2.26.2
>