freebsd-dev/sys/fs/devfs/devfs.h
Mateusz Guzik 3b44443626 devfs: rework si_usecount to track opens
This removes a lot of special casing from the VFS layer.

Reviewed by:	kib (previous version)
Tested by:	pho (previous version)
Differential Revision:	https://reviews.freebsd.org/D25612
2020-08-11 14:27:57 +00:00

214 lines
6.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 2000
* Poul-Henning Kamp. All rights reserved.
* Copyright (c) 2002
* Dima Dorfman. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kernfs.h 8.6 (Berkeley) 3/29/95
* From: FreeBSD: src/sys/miscfs/kernfs/kernfs.h 1.14
*
* $FreeBSD$
*/
#ifndef _FS_DEVFS_DEVFS_H_
#define _FS_DEVFS_DEVFS_H_
#define DEVFS_MAGIC 0xdb0a087a
/*
* Identifiers. The ruleset and rule numbers are 16-bit values. The
* "rule ID" is a combination of the ruleset and rule number; it
* should be able to univocally describe a rule in the system. In
* this implementation, the upper 16 bits of the rule ID is the
* ruleset number; the lower 16 bits, the rule number within the
* aforementioned ruleset.
*/
typedef uint16_t devfs_rnum;
typedef uint16_t devfs_rsnum;
typedef uint32_t devfs_rid;
/*
* Identifier manipulators.
*/
#define rid2rsn(rid) ((rid) >> 16)
#define rid2rn(rid) ((rid) & 0xffff)
#define mkrid(rsn, rn) ((rn) | ((rsn) << 16))
/*
* Plain DEVFS rule. This gets shared between kernel and userland
* verbatim, so it shouldn't contain any pointers or other kernel- or
* userland-specific values.
*/
struct devfs_rule {
uint32_t dr_magic; /* Magic number. */
devfs_rid dr_id; /* Identifier. */
/*
* Conditions under which this rule should be applied. These
* are ANDed together since OR can be simulated by using
* multiple rules. dr_icond determines which of the other
* variables we should process.
*/
int dr_icond;
#define DRC_DSWFLAGS 0x001
#define DRC_PATHPTRN 0x002
int dr_dswflags; /* cdevsw flags to match. */
#define DEVFS_MAXPTRNLEN 200
char dr_pathptrn[DEVFS_MAXPTRNLEN]; /* Pattern to match path. */
/*
* Things to change. dr_iacts determines which of the other
* variables we should process.
*/
int dr_iacts;
#define DRA_BACTS 0x001
#define DRA_UID 0x002
#define DRA_GID 0x004
#define DRA_MODE 0x008
#define DRA_INCSET 0x010
int dr_bacts; /* Boolean (on/off) action. */
#define DRB_HIDE 0x001 /* Hide entry (DE_WHITEOUT). */
#define DRB_UNHIDE 0x002 /* Unhide entry. */
uid_t dr_uid;
gid_t dr_gid;
mode_t dr_mode;
devfs_rsnum dr_incset; /* Included ruleset. */
};
/*
* Rule-related ioctls.
*/
#define DEVFSIO_RADD _IOWR('D', 0, struct devfs_rule)
#define DEVFSIO_RDEL _IOW('D', 1, devfs_rid)
#define DEVFSIO_RAPPLY _IOW('D', 2, struct devfs_rule)
#define DEVFSIO_RAPPLYID _IOW('D', 3, devfs_rid)
#define DEVFSIO_RGETNEXT _IOWR('D', 4, struct devfs_rule)
#define DEVFSIO_SUSE _IOW('D', 10, devfs_rsnum)
#define DEVFSIO_SAPPLY _IOW('D', 11, devfs_rsnum)
#define DEVFSIO_SGETNEXT _IOWR('D', 12, devfs_rsnum)
/* XXX: DEVFSIO_RS_GET_INFO for refcount, active if any, etc. */
#ifdef _KERNEL
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_DEVFS);
#endif
struct componentname;
TAILQ_HEAD(devfs_dlist_head, devfs_dirent);
struct devfs_dirent {
struct cdev_priv *de_cdp;
int de_inode;
int de_flags;
#define DE_WHITEOUT 0x01
#define DE_DOT 0x02
#define DE_DOTDOT 0x04
#define DE_DOOMED 0x08
#define DE_COVERED 0x10
#define DE_USER 0x20
int de_holdcnt;
struct dirent *de_dirent;
TAILQ_ENTRY(devfs_dirent) de_list;
struct devfs_dlist_head de_dlist;
struct devfs_dirent *de_dir;
int de_links;
mode_t de_mode;
uid_t de_uid;
gid_t de_gid;
struct label *de_label;
struct timespec de_atime;
struct timespec de_mtime;
struct timespec de_ctime;
struct vnode *de_vnode;
char *de_symlink;
int de_usecount;
};
struct devfs_mount {
u_int dm_idx;
struct mount *dm_mount;
struct devfs_dirent *dm_rootdir;
unsigned dm_generation;
int dm_holdcnt;
struct sx dm_lock;
devfs_rsnum dm_ruleset;
};
#define DEVFS_ROOTINO 2
extern unsigned devfs_rule_depth;
#define VFSTODEVFS(mp) ((struct devfs_mount *)((mp)->mnt_data))
#define DEVFS_DE_HOLD(de) ((de)->de_holdcnt++)
#define DEVFS_DE_DROP(de) (--(de)->de_holdcnt == 0)
#define DEVFS_DMP_HOLD(dmp) ((dmp)->dm_holdcnt++)
#define DEVFS_DMP_DROP(dmp) (--(dmp)->dm_holdcnt == 0)
#define DEVFS_DEL_VNLOCKED 0x01
#define DEVFS_DEL_NORECURSE 0x02
void devfs_rules_apply(struct devfs_mount *, struct devfs_dirent *);
void devfs_rules_cleanup(struct devfs_mount *);
int devfs_rules_ioctl(struct devfs_mount *, u_long, caddr_t,
struct thread *);
void devfs_ruleset_set(devfs_rsnum rsnum, struct devfs_mount *dm);
void devfs_ruleset_apply(struct devfs_mount *dm);
int devfs_allocv(struct devfs_dirent *, struct mount *, int,
struct vnode **);
char *devfs_fqpn(char *, struct devfs_mount *, struct devfs_dirent *,
struct componentname *);
void devfs_delete(struct devfs_mount *, struct devfs_dirent *, int);
void devfs_dirent_free(struct devfs_dirent *);
int devfs_populate_needed(struct devfs_mount *dm);
void devfs_populate(struct devfs_mount *);
void devfs_cleanup(struct devfs_mount *);
void devfs_unmount_final(struct devfs_mount *);
struct devfs_dirent *devfs_newdirent(char *, int);
struct devfs_dirent *devfs_parent_dirent(struct devfs_dirent *);
struct devfs_dirent *devfs_vmkdir(struct devfs_mount *, char *, int,
struct devfs_dirent *, u_int);
struct devfs_dirent *devfs_find(struct devfs_dirent *, const char *, int,
int);
void devfs_ctty_ref(struct vnode *);
void devfs_ctty_unref(struct vnode *);
int devfs_usecount(struct vnode *);
#endif /* _KERNEL */
#endif /* !_FS_DEVFS_DEVFS_H_ */