237 lines
8.1 KiB
C
237 lines
8.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/* Filesystem superblock creation and reconfiguration context.
|
|
*
|
|
* Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*/
|
|
|
|
#ifndef _LINUX_FS_CONTEXT_H
|
|
#define _LINUX_FS_CONTEXT_H
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/refcount.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/security.h>
|
|
#include <linux/mutex.h>
|
|
|
|
struct cred;
|
|
struct dentry;
|
|
struct file_operations;
|
|
struct file_system_type;
|
|
struct mnt_namespace;
|
|
struct net;
|
|
struct pid_namespace;
|
|
struct super_block;
|
|
struct user_namespace;
|
|
struct vfsmount;
|
|
struct path;
|
|
|
|
enum fs_context_purpose {
|
|
FS_CONTEXT_FOR_MOUNT, /* New superblock for explicit mount */
|
|
FS_CONTEXT_FOR_SUBMOUNT, /* New superblock for automatic submount */
|
|
FS_CONTEXT_FOR_RECONFIGURE, /* Superblock reconfiguration (remount) */
|
|
};
|
|
|
|
/*
|
|
* Userspace usage phase for fsopen/fspick.
|
|
*/
|
|
enum fs_context_phase {
|
|
FS_CONTEXT_CREATE_PARAMS, /* Loading params for sb creation */
|
|
FS_CONTEXT_CREATING, /* A superblock is being created */
|
|
FS_CONTEXT_AWAITING_MOUNT, /* Superblock created, awaiting fsmount() */
|
|
FS_CONTEXT_AWAITING_RECONF, /* Awaiting initialisation for reconfiguration */
|
|
FS_CONTEXT_RECONF_PARAMS, /* Loading params for reconfiguration */
|
|
FS_CONTEXT_RECONFIGURING, /* Reconfiguring the superblock */
|
|
FS_CONTEXT_FAILED, /* Failed to correctly transition a context */
|
|
};
|
|
|
|
/*
|
|
* Type of parameter value.
|
|
*/
|
|
enum fs_value_type {
|
|
fs_value_is_undefined,
|
|
fs_value_is_flag, /* Value not given a value */
|
|
fs_value_is_string, /* Value is a string */
|
|
fs_value_is_blob, /* Value is a binary blob */
|
|
fs_value_is_filename, /* Value is a filename* + dirfd */
|
|
fs_value_is_file, /* Value is a file* */
|
|
};
|
|
|
|
/*
|
|
* Configuration parameter.
|
|
*/
|
|
struct fs_parameter {
|
|
const char *key; /* Parameter name */
|
|
enum fs_value_type type:8; /* The type of value here */
|
|
union {
|
|
char *string;
|
|
void *blob;
|
|
struct filename *name;
|
|
struct file *file;
|
|
};
|
|
size_t size;
|
|
int dirfd;
|
|
};
|
|
|
|
struct p_log {
|
|
const char *prefix;
|
|
struct fc_log *log;
|
|
};
|
|
|
|
/*
|
|
* Filesystem context for holding the parameters used in the creation or
|
|
* reconfiguration of a superblock.
|
|
*
|
|
* Superblock creation fills in ->root whereas reconfiguration begins with this
|
|
* already set.
|
|
*
|
|
* See Documentation/filesystems/mount_api.rst
|
|
*/
|
|
struct fs_context {
|
|
const struct fs_context_operations *ops;
|
|
struct mutex uapi_mutex; /* Userspace access mutex */
|
|
struct file_system_type *fs_type;
|
|
void *fs_private; /* The filesystem's context */
|
|
void *sget_key;
|
|
struct dentry *root; /* The root and superblock */
|
|
struct user_namespace *user_ns; /* The user namespace for this mount */
|
|
struct net *net_ns; /* The network namespace for this mount */
|
|
const struct cred *cred; /* The mounter's credentials */
|
|
struct p_log log; /* Logging buffer */
|
|
const char *source; /* The source name (eg. dev path) */
|
|
void *security; /* LSM options */
|
|
void *s_fs_info; /* Proposed s_fs_info */
|
|
unsigned int sb_flags; /* Proposed superblock flags (SB_*) */
|
|
unsigned int sb_flags_mask; /* Superblock flags that were changed */
|
|
unsigned int s_iflags; /* OR'd with sb->s_iflags */
|
|
unsigned int lsm_flags; /* Information flags from the fs to the LSM */
|
|
enum fs_context_purpose purpose:8;
|
|
enum fs_context_phase phase:8; /* The phase the context is in */
|
|
bool need_free:1; /* Need to call ops->free() */
|
|
bool global:1; /* Goes into &init_user_ns */
|
|
bool oldapi:1; /* Coming from mount(2) */
|
|
};
|
|
|
|
struct fs_context_operations {
|
|
void (*free)(struct fs_context *fc);
|
|
int (*dup)(struct fs_context *fc, struct fs_context *src_fc);
|
|
int (*parse_param)(struct fs_context *fc, struct fs_parameter *param);
|
|
int (*parse_monolithic)(struct fs_context *fc, void *data);
|
|
int (*get_tree)(struct fs_context *fc);
|
|
int (*reconfigure)(struct fs_context *fc);
|
|
};
|
|
|
|
/*
|
|
* fs_context manipulation functions.
|
|
*/
|
|
extern struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
|
|
unsigned int sb_flags);
|
|
extern struct fs_context *fs_context_for_reconfigure(struct dentry *dentry,
|
|
unsigned int sb_flags,
|
|
unsigned int sb_flags_mask);
|
|
extern struct fs_context *fs_context_for_submount(struct file_system_type *fs_type,
|
|
struct dentry *reference);
|
|
|
|
extern struct fs_context *vfs_dup_fs_context(struct fs_context *fc);
|
|
extern int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param);
|
|
extern int vfs_parse_fs_string(struct fs_context *fc, const char *key,
|
|
const char *value, size_t v_size);
|
|
extern int generic_parse_monolithic(struct fs_context *fc, void *data);
|
|
extern int vfs_get_tree(struct fs_context *fc);
|
|
extern void put_fs_context(struct fs_context *fc);
|
|
extern int vfs_parse_fs_param_source(struct fs_context *fc,
|
|
struct fs_parameter *param);
|
|
extern void fc_drop_locked(struct fs_context *fc);
|
|
int reconfigure_single(struct super_block *s,
|
|
int flags, void *data);
|
|
|
|
extern int get_tree_nodev(struct fs_context *fc,
|
|
int (*fill_super)(struct super_block *sb,
|
|
struct fs_context *fc));
|
|
extern int get_tree_single(struct fs_context *fc,
|
|
int (*fill_super)(struct super_block *sb,
|
|
struct fs_context *fc));
|
|
extern int get_tree_single_reconf(struct fs_context *fc,
|
|
int (*fill_super)(struct super_block *sb,
|
|
struct fs_context *fc));
|
|
extern int get_tree_keyed(struct fs_context *fc,
|
|
int (*fill_super)(struct super_block *sb,
|
|
struct fs_context *fc),
|
|
void *key);
|
|
|
|
extern int get_tree_bdev(struct fs_context *fc,
|
|
int (*fill_super)(struct super_block *sb,
|
|
struct fs_context *fc));
|
|
|
|
extern const struct file_operations fscontext_fops;
|
|
|
|
/*
|
|
* Mount error, warning and informational message logging. This structure is
|
|
* shareable between a mount and a subordinate mount.
|
|
*/
|
|
struct fc_log {
|
|
refcount_t usage;
|
|
u8 head; /* Insertion index in buffer[] */
|
|
u8 tail; /* Removal index in buffer[] */
|
|
u8 need_free; /* Mask of kfree'able items in buffer[] */
|
|
struct module *owner; /* Owner module for strings that don't then need freeing */
|
|
char *buffer[8];
|
|
};
|
|
|
|
extern __attribute__((format(printf, 4, 5)))
|
|
void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...);
|
|
|
|
#define __logfc(fc, l, fmt, ...) logfc((fc)->log.log, NULL, \
|
|
l, fmt, ## __VA_ARGS__)
|
|
#define __plog(p, l, fmt, ...) logfc((p)->log, (p)->prefix, \
|
|
l, fmt, ## __VA_ARGS__)
|
|
/**
|
|
* infof - Store supplementary informational message
|
|
* @fc: The context in which to log the informational message
|
|
* @fmt: The format string
|
|
*
|
|
* Store the supplementary informational message for the process if the process
|
|
* has enabled the facility.
|
|
*/
|
|
#define infof(fc, fmt, ...) __logfc(fc, 'i', fmt, ## __VA_ARGS__)
|
|
#define info_plog(p, fmt, ...) __plog(p, 'i', fmt, ## __VA_ARGS__)
|
|
#define infofc(p, fmt, ...) __plog((&(fc)->log), 'i', fmt, ## __VA_ARGS__)
|
|
|
|
/**
|
|
* warnf - Store supplementary warning message
|
|
* @fc: The context in which to log the error message
|
|
* @fmt: The format string
|
|
*
|
|
* Store the supplementary warning message for the process if the process has
|
|
* enabled the facility.
|
|
*/
|
|
#define warnf(fc, fmt, ...) __logfc(fc, 'w', fmt, ## __VA_ARGS__)
|
|
#define warn_plog(p, fmt, ...) __plog(p, 'w', fmt, ## __VA_ARGS__)
|
|
#define warnfc(fc, fmt, ...) __plog((&(fc)->log), 'w', fmt, ## __VA_ARGS__)
|
|
|
|
/**
|
|
* errorf - Store supplementary error message
|
|
* @fc: The context in which to log the error message
|
|
* @fmt: The format string
|
|
*
|
|
* Store the supplementary error message for the process if the process has
|
|
* enabled the facility.
|
|
*/
|
|
#define errorf(fc, fmt, ...) __logfc(fc, 'e', fmt, ## __VA_ARGS__)
|
|
#define error_plog(p, fmt, ...) __plog(p, 'e', fmt, ## __VA_ARGS__)
|
|
#define errorfc(fc, fmt, ...) __plog((&(fc)->log), 'e', fmt, ## __VA_ARGS__)
|
|
|
|
/**
|
|
* invalf - Store supplementary invalid argument error message
|
|
* @fc: The context in which to log the error message
|
|
* @fmt: The format string
|
|
*
|
|
* Store the supplementary error message for the process if the process has
|
|
* enabled the facility and return -EINVAL.
|
|
*/
|
|
#define invalf(fc, fmt, ...) (errorf(fc, fmt, ## __VA_ARGS__), -EINVAL)
|
|
#define inval_plog(p, fmt, ...) (error_plog(p, fmt, ## __VA_ARGS__), -EINVAL)
|
|
#define invalfc(fc, fmt, ...) (errorfc(fc, fmt, ## __VA_ARGS__), -EINVAL)
|
|
|
|
#endif /* _LINUX_FS_CONTEXT_H */
|