fs: port ->setattr() to pass mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

4 files changed, 10 insertions, 10 deletions

diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index c397c51f80d9..9848a245fa6f 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -225,7 +225,7 @@ int v9fs_iop_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
 			 * FIXME should we update ctime ?
 			 * What is the following setxattr update the mode ?
 			 */
-			v9fs_vfs_setattr_dotl(&init_user_ns, dentry, &iattr);
+			v9fs_vfs_setattr_dotl(&nop_mnt_idmap, dentry, &iattr);
 		}
 		break;
 	case ACL_TYPE_DEFAULT:
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index bc417da7e9c1..75106b9f293d 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -60,7 +60,7 @@ void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
 int v9fs_uflags2omode(int uflags, int extended);
 
 void v9fs_blank_wstat(struct p9_wstat *wstat);
-int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
+int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct iattr *iattr);
 int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end,
 			 int datasync);
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 27a04a226d97..d8cd3f17bbf3 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1060,13 +1060,13 @@ v9fs_vfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 
 /**
  * v9fs_vfs_setattr - set file metadata
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dentry: file whose metadata to set
  * @iattr: metadata assignment structure
  *
  */
 
-static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
+static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
 			    struct dentry *dentry, struct iattr *iattr)
 {
 	int retval, use_dentry = 0;
@@ -1077,7 +1077,7 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
 	struct p9_wstat wstat;
 
 	p9_debug(P9_DEBUG_VFS, "\n");
-	retval = setattr_prepare(&init_user_ns, dentry, iattr);
+	retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (retval)
 		return retval;
 
@@ -1135,7 +1135,7 @@ static int v9fs_vfs_setattr(struct user_namespace *mnt_userns,
 
 	v9fs_invalidate_inode_attr(inode);
 
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	mark_inode_dirty(inode);
 	return 0;
 }
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index f806b3f11649..dfe6b4017bd0 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -529,13 +529,13 @@ static int v9fs_mapped_iattr_valid(int iattr_valid)
 
 /**
  * v9fs_vfs_setattr_dotl - set file metadata
- * @mnt_userns: The user namespace of the mount
+ * @idmap: idmap of the mount
  * @dentry: file whose metadata to set
  * @iattr: metadata assignment structure
  *
  */
 
-int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
+int v9fs_vfs_setattr_dotl(struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct iattr *iattr)
 {
 	int retval, use_dentry = 0;
@@ -548,7 +548,7 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
 
 	p9_debug(P9_DEBUG_VFS, "\n");
 
-	retval = setattr_prepare(&init_user_ns, dentry, iattr);
+	retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 	if (retval)
 		return retval;
 
@@ -597,7 +597,7 @@ int v9fs_vfs_setattr_dotl(struct user_namespace *mnt_userns,
 		truncate_setsize(inode, iattr->ia_size);
 
 	v9fs_invalidate_inode_attr(inode);
-	setattr_copy(&init_user_ns, inode, iattr);
+	setattr_copy(&nop_mnt_idmap, inode, iattr);
 	mark_inode_dirty(inode);
 	if (iattr->ia_valid & ATTR_MODE) {
 		/* We also want to update ACL when we update mode bits */