Unverified Commit 4609e1f1 authored by Christian Brauner's avatar Christian Brauner Committed by Christian Brauner (Microsoft)
Browse files

fs: port ->permission() to pass mnt_idmap 



Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed ("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: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
parent 8782a9ae

Documentation/filesystems/locking.rst

+1 −1
Original line number Diff line number Diff line
@@ -69,7 +69,7 @@ prototypes:: 
	int (*readlink) (struct dentry *, char __user *,int);

	const char *(*get_link) (struct dentry *, struct inode *, struct delayed_call *);

	void (*truncate) (struct inode *);

	int (*permission) (struct inode *, int, unsigned int);

	int (*permission) (struct mnt_idmap *, struct inode *, int, unsigned int);

	struct posix_acl * (*get_inode_acl)(struct inode *, int, bool);

	int (*setattr) (struct mnt_idmap *, struct dentry *, struct iattr *);

	int (*getattr) (struct mnt_idmap *, const struct path *, struct kstat *, u32, unsigned int);

Documentation/filesystems/vfs.rst

+1 −1
Original line number Diff line number Diff line
@@ -434,7 +434,7 @@ As of kernel 2.6.22, the following members are defined: 
		int (*readlink) (struct dentry *, char __user *,int);

		const char *(*get_link) (struct dentry *, struct inode *,

					 struct delayed_call *);

		int (*permission) (struct user_namespace *, struct inode *, int);

		int (*permission) (struct mnt_idmap *, struct inode *, int);

		struct posix_acl * (*get_inode_acl)(struct inode *, int, bool);

		int (*setattr) (struct mnt_idmap *, struct dentry *, struct iattr *);

		int (*getattr) (struct mnt_idmap *, const struct path *, struct kstat *, u32, unsigned int);

fs/afs/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -1387,7 +1387,7 @@ extern void afs_cache_permit(struct afs_vnode *, struct key *, unsigned int, 
extern struct key *afs_request_key(struct afs_cell *);

extern struct key *afs_request_key_rcu(struct afs_cell *);

extern int afs_check_permit(struct afs_vnode *, struct key *, afs_access_t *);

extern int afs_permission(struct user_namespace *, struct inode *, int);

extern int afs_permission(struct mnt_idmap *, struct inode *, int);

extern void __exit afs_clean_up_permit_cache(void);



/*

fs/afs/security.c

+1 −1
Original line number Diff line number Diff line
@@ -395,7 +395,7 @@ int afs_check_permit(struct afs_vnode *vnode, struct key *key, 
 * - AFS ACLs are attached to directories only, and a file is controlled by its

 *   parent directory's ACL

 */

int afs_permission(struct user_namespace *mnt_userns, struct inode *inode,

int afs_permission(struct mnt_idmap *idmap, struct inode *inode,

		   int mask)

{

	struct afs_vnode *vnode = AFS_FS_I(inode);

fs/attr.c

+4 −3
Original line number Diff line number Diff line
@@ -324,10 +324,11 @@ void setattr_copy(struct mnt_idmap *idmap, struct inode *inode, 
}

EXPORT_SYMBOL(setattr_copy);



int may_setattr(struct user_namespace *mnt_userns, struct inode *inode,

int may_setattr(struct mnt_idmap *idmap, struct inode *inode,

		unsigned int ia_valid)

{

	int error;

	struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);



	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {

		if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
@@ -343,7 +344,7 @@ int may_setattr(struct user_namespace *mnt_userns, struct inode *inode, 
			return -EPERM;



		if (!inode_owner_or_capable(mnt_userns, inode)) {

			error = inode_permission(mnt_userns, inode, MAY_WRITE);

			error = inode_permission(idmap, inode, MAY_WRITE);

			if (error)

				return error;

		}
@@ -391,7 +392,7 @@ int notify_change(struct mnt_idmap *idmap, struct dentry *dentry, 


	WARN_ON_ONCE(!inode_is_locked(inode));



	error = may_setattr(mnt_userns, inode, ia_valid);

	error = may_setattr(idmap, inode, ia_valid);

	if (error)

		return error;