fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/adfs/adfs.h b/fs/adfs/adfs.h
index 699c4fa8b78b..06b7c92343ad 100644
--- a/fs/adfs/adfs.h
+++ b/fs/adfs/adfs.h
@@ -144,7 +144,8 @@ struct adfs_discmap {
 /* Inode stuff */
 struct inode *adfs_iget(struct super_block *sb, struct object_info *obj);
 int adfs_write_inode(struct inode *inode, struct writeback_control *wbc);
-int adfs_notify_change(struct dentry *dentry, struct iattr *attr);
+int adfs_notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
+		       struct iattr *attr);
 
 /* map.c */
 int adfs_map_lookup(struct super_block *sb, u32 frag_id, unsigned int offset);