1/* $OpenBSD: file.h,v 1.66 2022/06/20 01:39:44 visa Exp $ */ 2/* $NetBSD: file.h,v 1.11 1995/03/26 20:24:13 jtc Exp $ */ 3 4/* 5 * Copyright (c) 1982, 1986, 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)file.h 8.2 (Berkeley) 8/20/94 33 */ 34 35#ifndef _KERNEL 36#include <sys/fcntl.h> 37 38#else /* _KERNEL */ 39#include <sys/queue.h> 40#include <sys/mutex.h> 41#endif /* _KERNEL */ 42 43#define DTYPE_VNODE 1 /* file */ 44#define DTYPE_SOCKET 2 /* communications endpoint */ 45#define DTYPE_PIPE 3 /* pipe */ 46#define DTYPE_KQUEUE 4 /* event queue */ 47#define DTYPE_DMABUF 5 /* DMA buffer (for DRM) */ 48#define DTYPE_SYNC 6 /* sync file (for DRM) */ 49 50#ifdef _KERNEL 51struct proc; 52struct uio; 53struct knote; 54struct stat; 55struct file; 56struct ucred; 57 58/** 59 * File operations. 60 * The following entries could be called without KERNEL_LOCK hold: 61 * - fo_read 62 * - fo_write 63 * - fo_close 64 */ 65struct fileops { 66 int (*fo_read)(struct file *, struct uio *, int); 67 int (*fo_write)(struct file *, struct uio *, int); 68 int (*fo_ioctl)(struct file *, u_long, caddr_t, struct proc *); 69 int (*fo_kqfilter)(struct file *, struct knote *); 70 int (*fo_stat)(struct file *, struct stat *, struct proc *); 71 int (*fo_close)(struct file *, struct proc *); 72 int (*fo_seek)(struct file *, off_t *, int, struct proc *); 73}; 74#define FO_POSITION 0x00000001 /* positioned read/write */ 75 76/* 77 * Kernel descriptor table. 78 * One entry for each open kernel vnode and socket. 79 * 80 * Locks used to protect struct members in this file: 81 * I immutable after creation 82 * F global `fhdlk' mutex 83 * a atomic operations 84 * f per file `f_mtx' 85 * v vnode lock 86 */ 87struct file { 88 LIST_ENTRY(file) f_list;/* [F] list of active files */ 89 struct mutex f_mtx; 90 u_int f_flag; /* [a] see fcntl.h */ 91 u_int f_iflags; /* [a] internal flags */ 92 int f_type; /* [I] descriptor type */ 93 u_int f_count; /* [a] reference count */ 94 struct ucred *f_cred; /* [I] credentials associated with descriptor */ 95 const struct fileops *f_ops; /* [I] file operation pointers */ 96 off_t f_offset; /* [f,v] offset */ 97 void *f_data; /* [I] private data */ 98 uint64_t f_rxfer; /* [f] total number of read transfers */ 99 uint64_t f_wxfer; /* [f] total number of write transfers */ 100 uint64_t f_seek; /* [f] total independent seek operations */ 101 uint64_t f_rbytes; /* [f] total bytes read */ 102 uint64_t f_wbytes; /* [f] total bytes written */ 103}; 104 105#define FIF_HASLOCK 0x01 /* descriptor holds advisory lock */ 106#define FIF_INSERTED 0x80 /* present in `filehead' */ 107 108#define FREF(fp) \ 109 do { \ 110 extern void vfs_stall_barrier(void); \ 111 vfs_stall_barrier(); \ 112 atomic_inc_int(&(fp)->f_count); \ 113 } while (0) 114 115#define FRELE(fp,p) \ 116 (atomic_dec_int_nv(&fp->f_count) == 0 ? fdrop(fp, p) : 0) 117 118#define FDUP_MAX_COUNT (UINT_MAX - 2 * MAXCPUS) 119 120int fdrop(struct file *, struct proc *); 121 122static inline off_t 123foffset(struct file *fp) 124{ 125 off_t offset; 126 127 mtx_enter(&fp->f_mtx); 128 offset = fp->f_offset; 129 mtx_leave(&fp->f_mtx); 130 return (offset); 131} 132 133LIST_HEAD(filelist, file); 134extern int maxfiles; /* kernel limit on number of open files */ 135extern int numfiles; /* actual number of open files */ 136extern const struct fileops socketops; /* socket operations for files */ 137extern const struct fileops vnops; /* vnode operations for files */ 138 139#endif /* _KERNEL */ 140