fs: port xattr to 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>

1 files changed, 6 insertions, 6 deletions

diff --git a/include/linux/ima.h b/include/linux/ima.h
index 5a0b2a285a18..6f470b658082 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -18,7 +18,7 @@ struct linux_binprm;
 extern enum hash_algo ima_get_current_hash_algo(void);
 extern int ima_bprm_check(struct linux_binprm *bprm);
 extern int ima_file_check(struct file *file, int mask);
-extern void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
+extern void ima_post_create_tmpfile(struct mnt_idmap *idmap,
 				    struct inode *inode);
 extern void ima_file_free(struct file *file);
 extern int ima_file_mmap(struct file *file, unsigned long prot);
@@ -30,7 +30,7 @@ extern int ima_read_file(struct file *file, enum kernel_read_file_id id,
 			 bool contents);
 extern int ima_post_read_file(struct file *file, void *buf, loff_t size,
 			      enum kernel_read_file_id id);
-extern void ima_post_path_mknod(struct user_namespace *mnt_userns,
+extern void ima_post_path_mknod(struct mnt_idmap *idmap,
 				struct dentry *dentry);
 extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
 extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size);
@@ -66,7 +66,7 @@ static inline int ima_file_check(struct file *file, int mask)
 	return 0;
 }
 
-static inline void ima_post_create_tmpfile(struct user_namespace *mnt_userns,
+static inline void ima_post_create_tmpfile(struct mnt_idmap *idmap,
 					   struct inode *inode)
 {
 }
@@ -111,7 +111,7 @@ static inline int ima_post_read_file(struct file *file, void *buf, loff_t size,
 	return 0;
 }
 
-static inline void ima_post_path_mknod(struct user_namespace *mnt_userns,
+static inline void ima_post_path_mknod(struct mnt_idmap *idmap,
 				       struct dentry *dentry)
 {
 	return;
@@ -183,7 +183,7 @@ static inline void ima_post_key_create_or_update(struct key *keyring,
 
 #ifdef CONFIG_IMA_APPRAISE
 extern bool is_ima_appraise_enabled(void);
-extern void ima_inode_post_setattr(struct user_namespace *mnt_userns,
+extern void ima_inode_post_setattr(struct mnt_idmap *idmap,
 				   struct dentry *dentry);
 extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
 		       const void *xattr_value, size_t xattr_value_len);
@@ -203,7 +203,7 @@ static inline bool is_ima_appraise_enabled(void)
 	return 0;
 }
 
-static inline void ima_inode_post_setattr(struct user_namespace *mnt_userns,
+static inline void ima_inode_post_setattr(struct mnt_idmap *idmap,
 					  struct dentry *dentry)
 {
 	return;