linux-stable/fs/internal.h
Al Viro e149ed2b80 take the targets of /proc/*/ns/* symlinks to separate fs
New pseudo-filesystem: nsfs.  Targets of /proc/*/ns/* live there now.
It's not mountable (not even registered, so it's not in /proc/filesystems,
etc.).  Files on it *are* bindable - we explicitly permit that in do_loopback().

This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
get_proc_ns() is a macro now (it's simply returning ->i_private; would
have been an inline, if not for header ordering headache).
proc_ns_inode() is an ex-parrot.  The interface used in procfs is
ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).

Dentries and inodes are never hashed; a non-counting reference to dentry
is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
if present.  See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
of that mechanism.

As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
from ns_get_path().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:30:20 -05:00

154 lines
3.6 KiB
C

/* fs/ internal definitions
*
* Copyright (C) 2006 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 License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
struct super_block;
struct file_system_type;
struct linux_binprm;
struct path;
struct mount;
/*
* block_dev.c
*/
#ifdef CONFIG_BLOCK
extern void __init bdev_cache_init(void);
extern int __sync_blockdev(struct block_device *bdev, int wait);
#else
static inline void bdev_cache_init(void)
{
}
static inline int __sync_blockdev(struct block_device *bdev, int wait)
{
return 0;
}
#endif
/*
* buffer.c
*/
extern void guard_bio_eod(int rw, struct bio *bio);
/*
* char_dev.c
*/
extern void __init chrdev_init(void);
/*
* namei.c
*/
extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *);
extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
const char *, unsigned int, struct path *);
/*
* namespace.c
*/
extern int copy_mount_options(const void __user *, unsigned long *);
extern char *copy_mount_string(const void __user *);
extern struct vfsmount *lookup_mnt(struct path *);
extern int finish_automount(struct vfsmount *, struct path *);
extern int sb_prepare_remount_readonly(struct super_block *);
extern void __init mnt_init(void);
extern int __mnt_want_write(struct vfsmount *);
extern int __mnt_want_write_file(struct file *);
extern void __mnt_drop_write(struct vfsmount *);
extern void __mnt_drop_write_file(struct file *);
/*
* fs_struct.c
*/
extern void chroot_fs_refs(const struct path *, const struct path *);
/*
* file_table.c
*/
extern struct file *get_empty_filp(void);
/*
* super.c
*/
extern int do_remount_sb(struct super_block *, int, void *, int);
extern bool grab_super_passive(struct super_block *sb);
extern struct dentry *mount_fs(struct file_system_type *,
int, const char *, void *);
extern struct super_block *user_get_super(dev_t);
/*
* open.c
*/
struct open_flags {
int open_flag;
umode_t mode;
int acc_mode;
int intent;
int lookup_flags;
};
extern struct file *do_filp_open(int dfd, struct filename *pathname,
const struct open_flags *op);
extern struct file *do_file_open_root(struct dentry *, struct vfsmount *,
const char *, const struct open_flags *);
extern long do_handle_open(int mountdirfd,
struct file_handle __user *ufh, int open_flag);
extern int open_check_o_direct(struct file *f);
/*
* inode.c
*/
extern spinlock_t inode_sb_list_lock;
extern long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
int nid);
extern void inode_add_lru(struct inode *inode);
/*
* fs-writeback.c
*/
extern void inode_wb_list_del(struct inode *inode);
extern long get_nr_dirty_inodes(void);
extern void evict_inodes(struct super_block *);
extern int invalidate_inodes(struct super_block *, bool);
/*
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
extern int d_set_mounted(struct dentry *dentry);
extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan,
int nid);
/*
* read_write.c
*/
extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
/*
* pipe.c
*/
extern const struct file_operations pipefifo_fops;
/*
* fs_pin.c
*/
extern void sb_pin_kill(struct super_block *sb);
extern void mnt_pin_kill(struct mount *m);
/*
* fs/nsfs.c
*/
extern struct dentry_operations ns_dentry_operations;