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549c729771
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>
162 lines
4.8 KiB
C
162 lines
4.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/* -*- mode: c; c-basic-offset:8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* configfs_internal.h - Internal stuff for configfs
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*
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* Based on sysfs:
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* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
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*
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* configfs Copyright (C) 2005 Oracle. All rights reserved.
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*/
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#ifdef pr_fmt
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#undef pr_fmt
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#endif
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/spinlock.h>
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struct configfs_fragment {
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atomic_t frag_count;
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struct rw_semaphore frag_sem;
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bool frag_dead;
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};
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void put_fragment(struct configfs_fragment *);
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struct configfs_fragment *get_fragment(struct configfs_fragment *);
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struct configfs_dirent {
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atomic_t s_count;
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int s_dependent_count;
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struct list_head s_sibling;
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struct list_head s_children;
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int s_links;
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void * s_element;
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int s_type;
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umode_t s_mode;
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struct dentry * s_dentry;
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struct iattr * s_iattr;
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#ifdef CONFIG_LOCKDEP
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int s_depth;
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#endif
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struct configfs_fragment *s_frag;
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};
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#define CONFIGFS_ROOT 0x0001
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#define CONFIGFS_DIR 0x0002
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#define CONFIGFS_ITEM_ATTR 0x0004
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#define CONFIGFS_ITEM_BIN_ATTR 0x0008
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#define CONFIGFS_ITEM_LINK 0x0020
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#define CONFIGFS_USET_DIR 0x0040
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#define CONFIGFS_USET_DEFAULT 0x0080
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#define CONFIGFS_USET_DROPPING 0x0100
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#define CONFIGFS_USET_IN_MKDIR 0x0200
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#define CONFIGFS_USET_CREATING 0x0400
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#define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)
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extern struct mutex configfs_symlink_mutex;
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extern spinlock_t configfs_dirent_lock;
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extern struct kmem_cache *configfs_dir_cachep;
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extern int configfs_is_root(struct config_item *item);
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extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
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extern struct inode *configfs_create(struct dentry *, umode_t mode);
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extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
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extern int configfs_create_bin_file(struct config_item *,
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const struct configfs_bin_attribute *);
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extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
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void *, umode_t, int, struct configfs_fragment *);
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extern int configfs_dirent_is_ready(struct configfs_dirent *);
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extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
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extern const unsigned char * configfs_get_name(struct configfs_dirent *sd);
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extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent);
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extern int configfs_setattr(struct user_namespace *mnt_userns,
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struct dentry *dentry, struct iattr *iattr);
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extern struct dentry *configfs_pin_fs(void);
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extern void configfs_release_fs(void);
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extern const struct file_operations configfs_dir_operations;
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extern const struct file_operations configfs_file_operations;
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extern const struct file_operations configfs_bin_file_operations;
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extern const struct inode_operations configfs_dir_inode_operations;
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extern const struct inode_operations configfs_root_inode_operations;
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extern const struct inode_operations configfs_symlink_inode_operations;
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extern const struct dentry_operations configfs_dentry_ops;
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extern int configfs_symlink(struct user_namespace *mnt_userns,
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struct inode *dir, struct dentry *dentry,
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const char *symname);
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extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
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int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
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struct dentry *dentry, char *body);
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static inline struct config_item * to_item(struct dentry * dentry)
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{
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struct configfs_dirent * sd = dentry->d_fsdata;
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return ((struct config_item *) sd->s_element);
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}
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static inline struct configfs_attribute * to_attr(struct dentry * dentry)
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{
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struct configfs_dirent * sd = dentry->d_fsdata;
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return ((struct configfs_attribute *) sd->s_element);
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}
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static inline struct configfs_bin_attribute *to_bin_attr(struct dentry *dentry)
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{
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struct configfs_attribute *attr = to_attr(dentry);
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return container_of(attr, struct configfs_bin_attribute, cb_attr);
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}
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static inline struct config_item *configfs_get_config_item(struct dentry *dentry)
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{
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struct config_item * item = NULL;
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spin_lock(&dentry->d_lock);
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if (!d_unhashed(dentry)) {
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struct configfs_dirent * sd = dentry->d_fsdata;
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item = config_item_get(sd->s_element);
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}
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spin_unlock(&dentry->d_lock);
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return item;
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}
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static inline void release_configfs_dirent(struct configfs_dirent * sd)
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{
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if (!(sd->s_type & CONFIGFS_ROOT)) {
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kfree(sd->s_iattr);
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put_fragment(sd->s_frag);
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kmem_cache_free(configfs_dir_cachep, sd);
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}
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}
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static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd)
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{
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if (sd) {
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WARN_ON(!atomic_read(&sd->s_count));
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atomic_inc(&sd->s_count);
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}
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return sd;
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}
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static inline void configfs_put(struct configfs_dirent * sd)
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{
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WARN_ON(!atomic_read(&sd->s_count));
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if (atomic_dec_and_test(&sd->s_count))
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release_configfs_dirent(sd);
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}
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