linux_dsm_epyc7002/include/linux/fs_context.h
Al Viro e1a91586d5 fs_context flavour for submounts
This is an eventual replacement for vfs_submount() uses.  Unlike the
"mount" and "remount" cases, the users of that thing are not in VFS -
they are buried in various ->d_automount() instances and rather than
converting them all at once we introduce the (thankfully small and
simple) infrastructure here and deal with the prospective users in
afs, nfs, etc. parts of the series.

Here we just introduce a new constructor (fs_context_for_submount())
along with the corresponding enum constant to be put into fc->purpose
for those.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-01-30 17:44:27 -05:00

72 lines
2.4 KiB
C

/* Filesystem superblock creation and reconfiguration context.
*
* Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _LINUX_FS_CONTEXT_H
#define _LINUX_FS_CONTEXT_H
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/security.h>
struct cred;
struct dentry;
struct file_operations;
struct file_system_type;
struct net;
struct user_namespace;
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) */
};
/*
* 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/mounting.txt
*/
struct fs_context {
struct file_system_type *fs_type;
void *fs_private; /* The filesystem's context */
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 */
const char *source; /* The source name (eg. dev path) */
const char *subtype; /* The subtype to set on the superblock */
void *security; /* Linux S&M options */
unsigned int sb_flags; /* Proposed superblock flags (SB_*) */
unsigned int sb_flags_mask; /* Superblock flags that were changed */
enum fs_context_purpose purpose:8;
bool need_free:1; /* Need to call ops->free() */
};
/*
* 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 int vfs_get_tree(struct fs_context *fc);
extern void put_fs_context(struct fs_context *fc);
#endif /* _LINUX_FS_CONTEXT_H */