freebsd-dev/sys/fs/devfs/devfs.h
Poul-Henning Kamp 93bcdfe270 Add refcounts to the "global" DEVFS inode slots, this allows us
to recycle inodes after a destroy_dev() but not until all mounts
have picked up the change.

Add support for an overflow table for DEVFS inodes.  The static
table defaults to 1024 inodes, if that fills, an overflow table
of 32k inodes is allocated.  Both numbers can be changed at
compile time, the size of the overflow table also with the
sysctl vfs.devfs.noverflow.

Use atomic instructions to barrier between make_dev()/destroy_dev()
and the mounts.

Add lockmgr() locking of directories for operations accessing or
modifying the directory TAILQs.

Various nitpicking here and there.
2000-09-06 11:26:43 +00:00

119 lines
3.9 KiB
C

/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 2000
* Poul-Henning Kamp. 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_
#ifdef _KERNEL /* No userland stuff in here... */
/*
* These are default sizes for the DEVFS inode table and the overflow
* table. If the default table overflows we allocate the overflow
* table, the size of which can also be set with a sysctl. If the
* overflow table fills you're toast.
*/
#ifndef NDEVFSINO
#define NDEVFSINO 1024
#endif
#ifndef NDEVFSOVERFLOW
#define NDEVFSOVERFLOW 32768
#endif
/*
* This is the first "per mount" inode, these are used for directories
* and symlinks and the like. Must be larger than the number of "true"
* device nodes and symlinks. It is.
*/
#define DEVFSINOMOUNT 0x2000000
MALLOC_DECLARE(M_DEVFS);
struct devfs_dirent {
int de_inode;
int de_flags;
#define DE_ORPHAN 0x1
#define DE_DOT 0x2
#define DE_DOTDOT 0x4
struct dirent *de_dirent;
TAILQ_ENTRY(devfs_dirent) de_list;
TAILQ_HEAD(, devfs_dirent) de_dlist;
struct devfs_dirent *de_dir;
int de_links;
mode_t de_mode;
uid_t de_uid;
gid_t de_gid;
struct timespec de_atime;
struct timespec de_mtime;
struct timespec de_ctime;
struct vnode *de_vnode;
char * de_symlink;
};
struct devfs_mount {
struct vnode *dm_root; /* Root node */
struct devfs_dirent *dm_rootdir;
struct devfs_dirent *dm_basedir;
unsigned dm_generation;
struct devfs_dirent *dm_dirent[NDEVFSINO];
struct devfs_dirent **dm_overflow;
int dm_inode;
struct lock dm_lock;
};
/*
* This is what we fill in dm_dirent[N] for a deleted entry.
*/
#define DE_DELETED ((struct devfs_dirent *)sizeof(struct devfs_dirent))
#define VFSTODEVFS(mp) ((struct devfs_mount *)((mp)->mnt_data))
extern vop_t **devfs_vnodeop_p;
extern vop_t **devfs_specop_p;
int devfs_allocv (struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct proc *p);
void devfs_attemptoverflow(int insist);
struct devfs_dirent *devfs_find (struct devfs_dirent *dd, const char *name, int namelen);
dev_t *devfs_itod (int inode);
struct devfs_dirent **devfs_itode (struct devfs_mount *dm, int inode);
int devfs_populate (struct devfs_mount *dm);
struct devfs_dirent *devfs_newdirent (char *name, int namelen);
void devfs_purge (struct devfs_dirent *dd);
struct devfs_dirent *devfs_vmkdir (char *name, int namelen, struct devfs_dirent *dotdot);
#endif /* _KERNEL */
#endif /* _FS_DEVFS_DEVFS_H_ */