| 1 | /* $NetBSD: filedesc.h,v 1.63 2012/02/11 23:16:18 martin Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2008 The NetBSD Foundation, Inc. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
| 17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| 18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
| 20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 26 | * POSSIBILITY OF SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | /* |
| 30 | * Copyright (c) 1990, 1993 |
| 31 | * The Regents of the University of California. All rights reserved. |
| 32 | * |
| 33 | * Redistribution and use in source and binary forms, with or without |
| 34 | * modification, are permitted provided that the following conditions |
| 35 | * are met: |
| 36 | * 1. Redistributions of source code must retain the above copyright |
| 37 | * notice, this list of conditions and the following disclaimer. |
| 38 | * 2. Redistributions in binary form must reproduce the above copyright |
| 39 | * notice, this list of conditions and the following disclaimer in the |
| 40 | * documentation and/or other materials provided with the distribution. |
| 41 | * 3. Neither the name of the University nor the names of its contributors |
| 42 | * may be used to endorse or promote products derived from this software |
| 43 | * without specific prior written permission. |
| 44 | * |
| 45 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 46 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 47 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 48 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 49 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 50 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 51 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 52 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 53 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 54 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 55 | * SUCH DAMAGE. |
| 56 | * |
| 57 | * @(#)filedesc.h 8.1 (Berkeley) 6/2/93 |
| 58 | */ |
| 59 | |
| 60 | #ifndef _SYS_FILEDESC_H_ |
| 61 | #define _SYS_FILEDESC_H_ |
| 62 | |
| 63 | #include <sys/param.h> |
| 64 | #include <sys/queue.h> |
| 65 | #include <sys/mutex.h> |
| 66 | #include <sys/rwlock.h> |
| 67 | #include <sys/condvar.h> |
| 68 | |
| 69 | /* |
| 70 | * This structure is used for the management of descriptors. It may be |
| 71 | * shared by multiple processes. |
| 72 | * |
| 73 | * A process is initially started out with NDFILE descriptors stored within |
| 74 | * this structure, selected to be enough for typical applications based on |
| 75 | * the historical limit of 20 open files (and the usage of descriptors by |
| 76 | * shells). If these descriptors are exhausted, a larger descriptor table |
| 77 | * may be allocated, up to a process' resource limit; the internal arrays |
| 78 | * are then unused. The initial expansion is set to NDEXTENT; each time |
| 79 | * it runs out, it is doubled until the resource limit is reached. NDEXTENT |
| 80 | * should be selected to be the biggest multiple of OFILESIZE (see below) |
| 81 | * that will fit in a power-of-two sized piece of memory. |
| 82 | */ |
| 83 | #define NDFILE 20 |
| 84 | #define NDEXTENT 50 /* 250 bytes in 256-byte alloc */ |
| 85 | #define NDENTRIES 32 /* 32 fds per entry */ |
| 86 | #define NDENTRYMASK (NDENTRIES - 1) |
| 87 | #define NDENTRYSHIFT 5 /* bits per entry */ |
| 88 | #define NDLOSLOTS(x) (((x) + NDENTRIES - 1) >> NDENTRYSHIFT) |
| 89 | #define NDHISLOTS(x) ((NDLOSLOTS(x) + NDENTRIES - 1) >> NDENTRYSHIFT) |
| 90 | #define NDFDFILE 6 /* first 6 descriptors are free */ |
| 91 | |
| 92 | /* |
| 93 | * Process-private descriptor reference, one for each descriptor slot |
| 94 | * in use. Locks: |
| 95 | * |
| 96 | * : unlocked |
| 97 | * a atomic operations + filedesc_t::fd_lock in some cases |
| 98 | * d filedesc_t::fd_lock |
| 99 | * |
| 100 | * Note that ff_exclose and ff_allocated are likely to be byte sized |
| 101 | * (bool). In general adjacent sub-word sized fields must be locked |
| 102 | * the same way, but in this case it's ok: ff_exclose can only be |
| 103 | * modified while the descriptor slot is live, and ff_allocated when |
| 104 | * it's invalid. |
| 105 | */ |
| 106 | typedef struct fdfile { |
| 107 | bool ff_exclose; /* :: close on exec flag */ |
| 108 | bool ff_allocated; /* d: descriptor slot is allocated */ |
| 109 | u_int ff_refcnt; /* a: reference count on structure */ |
| 110 | struct file *ff_file; /* d: pointer to file if open */ |
| 111 | SLIST_HEAD(,knote) ff_knlist; /* d: knotes attached to this fd */ |
| 112 | kcondvar_t ff_closing; /* d: notifier for close */ |
| 113 | } fdfile_t; |
| 114 | |
| 115 | /* Reference count */ |
| 116 | #define FR_CLOSING (0x80000000) /* closing: must interlock */ |
| 117 | #define FR_MASK (~FR_CLOSING) /* reference count */ |
| 118 | |
| 119 | /* |
| 120 | * Open file table, potentially many 'active' tables per filedesc_t |
| 121 | * in a multi-threaded process, or with a shared filedesc_t (clone()). |
| 122 | * nfiles is first to avoid pointer arithmetic. |
| 123 | */ |
| 124 | typedef struct fdtab { |
| 125 | u_int dt_nfiles; /* number of open files allocated */ |
| 126 | struct fdtab *dt_link; /* for lists of dtab */ |
| 127 | fdfile_t *dt_ff[NDFILE]; /* file structures for open fds */ |
| 128 | } fdtab_t; |
| 129 | |
| 130 | typedef struct filedesc { |
| 131 | /* |
| 132 | * Built-in fdfile_t records first, since they have strict |
| 133 | * alignment requirements. |
| 134 | */ |
| 135 | uint8_t fd_dfdfile[NDFDFILE][CACHE_LINE_SIZE]; |
| 136 | /* |
| 137 | * All of the remaining fields are locked by fd_lock. |
| 138 | */ |
| 139 | kmutex_t fd_lock; /* lock on structure */ |
| 140 | fdtab_t * volatile fd_dt; /* active descriptor table */ |
| 141 | uint32_t *fd_himap; /* each bit points to 32 fds */ |
| 142 | uint32_t *fd_lomap; /* bitmap of free fds */ |
| 143 | struct klist *fd_knhash; /* hash of attached non-fd knotes */ |
| 144 | int fd_lastkqfile; /* max descriptor for kqueue */ |
| 145 | int fd_lastfile; /* high-water mark of fd_ofiles */ |
| 146 | int fd_refcnt; /* reference count */ |
| 147 | u_long fd_knhashmask; /* size of fd_knhash */ |
| 148 | int fd_freefile; /* approx. next free file */ |
| 149 | int fd_unused; /* unused */ |
| 150 | bool fd_exclose; /* non-zero if >0 fd with EXCLOSE */ |
| 151 | /* |
| 152 | * This structure is used when the number of open files is |
| 153 | * <= NDFILE, and are then pointed to by the pointers above. |
| 154 | */ |
| 155 | fdtab_t fd_dtbuiltin; |
| 156 | /* |
| 157 | * These arrays are used when the number of open files is |
| 158 | * <= 1024, and are then pointed to by the pointers above. |
| 159 | */ |
| 160 | #define fd_startzero fd_dhimap /* area to zero on return to cache */ |
| 161 | uint32_t fd_dhimap[NDENTRIES >> NDENTRYSHIFT]; |
| 162 | uint32_t fd_dlomap[NDENTRIES]; |
| 163 | } filedesc_t; |
| 164 | |
| 165 | typedef struct cwdinfo { |
| 166 | struct vnode *cwdi_cdir; /* current directory */ |
| 167 | struct vnode *cwdi_rdir; /* root directory */ |
| 168 | struct vnode *cwdi_edir; /* emulation root (if known) */ |
| 169 | krwlock_t cwdi_lock; /* lock on entire struct */ |
| 170 | u_short cwdi_cmask; /* mask for file creation */ |
| 171 | u_int cwdi_refcnt; /* reference count */ |
| 172 | } cwdinfo_t; |
| 173 | |
| 174 | #ifdef _KERNEL |
| 175 | |
| 176 | struct fileops; |
| 177 | struct socket; |
| 178 | struct proc; |
| 179 | |
| 180 | /* |
| 181 | * Kernel global variables and routines. |
| 182 | */ |
| 183 | void fd_sys_init(void); |
| 184 | int fd_open(const char*, int, int, int*); |
| 185 | int fd_dupopen(int, int *, int, int); |
| 186 | int fd_alloc(struct proc *, int, int *); |
| 187 | void fd_tryexpand(struct proc *); |
| 188 | int fd_allocfile(file_t **, int *); |
| 189 | void fd_affix(struct proc *, file_t *, unsigned); |
| 190 | void fd_abort(struct proc *, file_t *, unsigned); |
| 191 | filedesc_t *fd_copy(void); |
| 192 | filedesc_t *fd_init(filedesc_t *); |
| 193 | void fd_share(proc_t *); |
| 194 | void fd_hold(lwp_t *); |
| 195 | void fd_free(void); |
| 196 | void fd_closeexec(void); |
| 197 | void fd_ktrexecfd(void); |
| 198 | int fd_checkstd(void); |
| 199 | file_t *fd_getfile(unsigned); |
| 200 | file_t *fd_getfile2(proc_t *, unsigned); |
| 201 | void fd_putfile(unsigned); |
| 202 | int fd_getvnode(unsigned, file_t **); |
| 203 | int fd_getsock(unsigned, struct socket **); |
| 204 | int fd_getsock1(unsigned, struct socket **, file_t **); |
| 205 | void fd_putvnode(unsigned); |
| 206 | void fd_putsock(unsigned); |
| 207 | int fd_close(unsigned); |
| 208 | int fd_dup(file_t *, int, int *, bool); |
| 209 | int fd_dup2(file_t *, unsigned, int); |
| 210 | int fd_clone(file_t *, unsigned, int, const struct fileops *, void *); |
| 211 | void fd_set_exclose(struct lwp *, int, bool); |
| 212 | int pipe1(struct lwp *, register_t *, int); |
| 213 | int dodup(struct lwp *, int, int, int, register_t *); |
| 214 | |
| 215 | void cwd_sys_init(void); |
| 216 | struct cwdinfo *cwdinit(void); |
| 217 | void cwdshare(proc_t *); |
| 218 | void cwdunshare(proc_t *); |
| 219 | void cwdfree(struct cwdinfo *); |
| 220 | void cwdexec(struct proc *); |
| 221 | |
| 222 | #define GETCWD_CHECK_ACCESS 0x0001 |
| 223 | int getcwd_common(struct vnode *, struct vnode *, char **, char *, int, |
| 224 | int, struct lwp *); |
| 225 | int vnode_to_path(char *, size_t, struct vnode *, struct lwp *, |
| 226 | struct proc *); |
| 227 | |
| 228 | int closef(file_t *); |
| 229 | file_t *fgetdummy(void); |
| 230 | void fputdummy(file_t *); |
| 231 | |
| 232 | struct stat; |
| 233 | int do_sys_fstat(int, struct stat *); |
| 234 | struct flock; |
| 235 | int do_fcntl_lock(int, int, struct flock *); |
| 236 | int do_posix_fadvise(int, off_t, off_t, int); |
| 237 | |
| 238 | extern kmutex_t filelist_lock; |
| 239 | extern filedesc_t filedesc0; |
| 240 | |
| 241 | #endif /* _KERNEL */ |
| 242 | |
| 243 | #endif /* !_SYS_FILEDESC_H_ */ |
| 244 | |