xref: /freebsd/sys/sys/file.h (revision 1265516c5c610fbc0d65451140e3f17b358cd015)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_FILE_H_
33 #define	_SYS_FILE_H_
34 
35 #ifndef _KERNEL
36 #include <sys/types.h> /* XXX */
37 #include <sys/fcntl.h>
38 #include <sys/unistd.h>
39 #else
40 #include <sys/errno.h>
41 #include <sys/_lock.h>
42 #include <sys/_mutex.h>
43 #include <sys/_null.h>
44 #include <sys/queue.h>
45 #include <sys/refcount.h>
46 #include <vm/vm.h>
47 
48 struct filedesc;
49 struct proc;
50 struct stat;
51 struct thread;
52 struct uio;
53 struct knote;
54 struct vnode;
55 struct nameidata;
56 
57 #endif /* _KERNEL */
58 
59 #define	DTYPE_NONE	0	/* not yet initialized */
60 #define	DTYPE_VNODE	1	/* file */
61 #define	DTYPE_SOCKET	2	/* communications endpoint */
62 #define	DTYPE_PIPE	3	/* pipe */
63 #define	DTYPE_FIFO	4	/* fifo (named pipe) */
64 #define	DTYPE_KQUEUE	5	/* event queue */
65 #define	DTYPE_CRYPTO	6	/* crypto */
66 #define	DTYPE_MQUEUE	7	/* posix message queue */
67 #define	DTYPE_SHM	8	/* swap-backed shared memory */
68 #define	DTYPE_SEM	9	/* posix semaphore */
69 #define	DTYPE_PTS	10	/* pseudo teletype master device */
70 #define	DTYPE_DEV	11	/* Device specific fd type */
71 #define	DTYPE_PROCDESC	12	/* process descriptor */
72 #define	DTYPE_EVENTFD	13	/* eventfd */
73 #define	DTYPE_TIMERFD	14	/* timerfd */
74 #define	DTYPE_INOTIFY	15	/* inotify descriptor */
75 #define	DTYPE_JAILDESC	16	/* jail descriptor */
76 
77 #ifdef _KERNEL
78 
79 struct file;
80 struct filecaps;
81 struct kaiocb;
82 struct kinfo_file;
83 struct ucred;
84 
85 #define	FOF_OFFSET	0x01	/* Use the offset in uio argument */
86 #define	FOF_NOLOCK	0x02	/* Do not take FOFFSET_LOCK */
87 #define	FOF_NEXTOFF_R	0x04	/* Also update f_nextoff[UIO_READ] */
88 #define	FOF_NEXTOFF_W	0x08	/* Also update f_nextoff[UIO_WRITE] */
89 #define	FOF_NOUPDATE	0x10	/* Do not update f_offset */
90 off_t foffset_lock(struct file *fp, int flags);
91 void foffset_lock_pair(struct file *fp1, off_t *off1p, struct file *fp2,
92     off_t *off2p, int flags);
93 void foffset_lock_uio(struct file *fp, struct uio *uio, int flags);
94 void foffset_unlock(struct file *fp, off_t val, int flags);
95 void foffset_unlock_uio(struct file *fp, struct uio *uio, int flags);
96 void fsetfl_lock(struct file *fp);
97 void fsetfl_unlock(struct file *fp);
98 
99 static inline off_t
foffset_get(struct file * fp)100 foffset_get(struct file *fp)
101 {
102 
103 	return (foffset_lock(fp, FOF_NOLOCK));
104 }
105 
106 typedef int fo_rdwr_t(struct file *fp, struct uio *uio,
107 		    struct ucred *active_cred, int flags,
108 		    struct thread *td);
109 typedef	int fo_truncate_t(struct file *fp, off_t length,
110 		    struct ucred *active_cred, struct thread *td);
111 typedef	int fo_ioctl_t(struct file *fp, u_long com, void *data,
112 		    struct ucred *active_cred, struct thread *td);
113 typedef	int fo_poll_t(struct file *fp, int events,
114 		    struct ucred *active_cred, struct thread *td);
115 typedef	int fo_kqfilter_t(struct file *fp, struct knote *kn);
116 typedef	int fo_stat_t(struct file *fp, struct stat *sb,
117 		    struct ucred *active_cred);
118 typedef	int fo_close_t(struct file *fp, struct thread *td);
119 typedef	int fo_chmod_t(struct file *fp, mode_t mode,
120 		    struct ucred *active_cred, struct thread *td);
121 typedef	int fo_chown_t(struct file *fp, uid_t uid, gid_t gid,
122 		    struct ucred *active_cred, struct thread *td);
123 typedef int fo_sendfile_t(struct file *fp, int sockfd, struct uio *hdr_uio,
124 		    struct uio *trl_uio, off_t offset, size_t nbytes,
125 		    off_t *sent, int flags, struct thread *td);
126 typedef int fo_seek_t(struct file *fp, off_t offset, int whence,
127 		    struct thread *td);
128 typedef int fo_fill_kinfo_t(struct file *fp, struct kinfo_file *kif,
129 		    struct filedesc *fdp);
130 typedef int fo_mmap_t(struct file *fp, vm_map_t map, vm_offset_t *addr,
131 		    vm_size_t size, vm_prot_t prot, vm_prot_t cap_maxprot,
132 		    int flags, vm_ooffset_t foff, struct thread *td);
133 typedef int fo_aio_queue_t(struct file *fp, struct kaiocb *job);
134 typedef int fo_add_seals_t(struct file *fp, int flags);
135 typedef int fo_get_seals_t(struct file *fp, int *flags);
136 typedef int fo_fallocate_t(struct file *fp, off_t offset, off_t len,
137 		    struct thread *td);
138 typedef int fo_fspacectl_t(struct file *fp, int cmd,
139 		    off_t *offset, off_t *length, int flags,
140 		    struct ucred *active_cred, struct thread *td);
141 typedef int fo_cmp_t(struct file *fp, struct file *fp1, struct thread *td);
142 typedef	int fo_fork_t(struct filedesc *fdp, struct file *fp, struct file **fp1,
143 		    struct proc *p1, struct thread *td);
144 typedef int fo_spare_t(struct file *fp);
145 typedef	int fo_flags_t;
146 
147 struct fileops {
148 	fo_rdwr_t	*fo_read;
149 	fo_rdwr_t	*fo_write;
150 	fo_truncate_t	*fo_truncate;
151 	fo_ioctl_t	*fo_ioctl;
152 	fo_poll_t	*fo_poll;
153 	fo_kqfilter_t	*fo_kqfilter;
154 	fo_stat_t	*fo_stat;
155 	fo_close_t	*fo_close;
156 	fo_chmod_t	*fo_chmod;
157 	fo_chown_t	*fo_chown;
158 	fo_sendfile_t	*fo_sendfile;
159 	fo_seek_t	*fo_seek;
160 	fo_fill_kinfo_t	*fo_fill_kinfo;
161 	fo_mmap_t	*fo_mmap;
162 	fo_aio_queue_t	*fo_aio_queue;
163 	fo_add_seals_t	*fo_add_seals;
164 	fo_get_seals_t	*fo_get_seals;
165 	fo_fallocate_t	*fo_fallocate;
166 	fo_fspacectl_t	*fo_fspacectl;
167 	fo_cmp_t	*fo_cmp;
168 	fo_fork_t	*fo_fork;
169 	fo_spare_t	*fo_spares[8];	/* Spare slots */
170 	fo_flags_t	fo_flags;	/* DFLAG_* below */
171 };
172 
173 #define DFLAG_PASSABLE	0x01	/* may be passed via unix sockets. */
174 #define DFLAG_SEEKABLE	0x02	/* seekable / nonsequential */
175 #define	DFLAG_FORK	0x04	/* copy on fork */
176 #endif /* _KERNEL */
177 
178 #if defined(_KERNEL) || defined(_WANT_FILE)
179 /*
180  * Kernel descriptor table.
181  * One entry for each open kernel vnode and socket.
182  *
183  * Below is the list of locks that protects members in struct file.
184  *
185  * (a) f_vnode lock required (shared allows both reads and writes)
186  * (f) updated with atomics and blocking on sleepq
187  * (d) cdevpriv_mtx
188  * none	not locked
189  */
190 
191 #if __BSD_VISIBLE
192 struct fadvise_info {
193 	int		fa_advice;	/* (f) FADV_* type. */
194 	off_t		fa_start;	/* (f) Region start. */
195 	off_t		fa_end;		/* (f) Region end. */
196 };
197 
198 struct file {
199 	volatile u_int	f_flag;		/* see fcntl.h */
200 	volatile u_int 	f_count;	/* reference count */
201 	void		*f_data;	/* file descriptor specific data */
202 	const struct fileops *f_ops;	/* File operations */
203 	struct vnode 	*f_vnode;	/* NULL or applicable vnode */
204 	struct ucred	*f_cred;	/* associated credentials. */
205 	short		f_type;		/* descriptor type */
206 	short		f_vflags;	/* (f) Sleep lock flags for members */
207 	/*
208 	 *  DTYPE_VNODE specific fields.
209 	 */
210 	union {
211 		int16_t	f_seqcount[2];	/* (a) Count of seq. reads and writes. */
212 		int	f_pipegen;
213 	};
214 	off_t		f_nextoff[2];	/* next expected read/write offset. */
215 	union {
216 		struct cdev_privdata *fvn_cdevpriv;
217 					/* (d) Private data for the cdev. */
218 		struct fadvise_info *fvn_advice;
219 	} f_vnun;
220 	/*
221 	 *  DFLAG_SEEKABLE specific fields
222 	 */
223 	off_t		f_offset;
224 };
225 
226 #define	f_cdevpriv	f_vnun.fvn_cdevpriv
227 #define	f_advice	f_vnun.fvn_advice
228 
229 #define	FILE_V_FOFFSET_LOCKED		0x0001
230 #define	FILE_V_FOFFSET_LOCK_WAITING	0x0002
231 #define	FILE_V_SETFL_LOCKED		0x0004
232 #define	FILE_V_SETFL_LOCK_WAITING	0x0008
233 #endif /* __BSD_VISIBLE */
234 
235 #endif /* _KERNEL || _WANT_FILE */
236 
237 /*
238  * Userland version of struct file, for sysctl
239  */
240 #if __BSD_VISIBLE
241 struct xfile {
242 	ksize_t	xf_size;	/* size of struct xfile */
243 	pid_t	xf_pid;		/* owning process */
244 	uid_t	xf_uid;		/* effective uid of owning process */
245 	int	xf_fd;		/* descriptor number */
246 	int	_xf_int_pad1;
247 	kvaddr_t xf_file;	/* address of struct file */
248 	short	xf_type;	/* descriptor type */
249 	short	_xf_short_pad1;
250 	int	xf_count;	/* reference count */
251 	int	xf_msgcount;	/* references from message queue */
252 	int	_xf_int_pad2;
253 	off_t	xf_offset;	/* file offset */
254 	kvaddr_t xf_data;	/* file descriptor specific data */
255 	kvaddr_t xf_vnode;	/* vnode pointer */
256 	u_int	xf_flag;	/* flags (see fcntl.h) */
257 	int	_xf_int_pad3;
258 	int64_t	_xf_int64_pad[6];
259 };
260 #endif /* __BSD_VISIBLE */
261 
262 #ifdef _KERNEL
263 
264 extern const struct fileops vnops;
265 extern const struct fileops badfileops;
266 extern const struct fileops path_fileops;
267 extern const struct fileops socketops;
268 extern int maxfiles;		/* kernel limit on number of open files */
269 extern int maxfilesperproc;	/* per process limit on number of open files */
270 
271 int fget(struct thread *td, int fd, const cap_rights_t *rightsp,
272     struct file **fpp);
273 int fget_mmap(struct thread *td, int fd, const cap_rights_t *rightsp,
274     vm_prot_t *maxprotp, struct file **fpp);
275 int fget_read(struct thread *td, int fd, const cap_rights_t *rightsp,
276     struct file **fpp);
277 int fget_write(struct thread *td, int fd, const cap_rights_t *rightsp,
278     struct file **fpp);
279 int fget_fcntl(struct thread *td, int fd, const cap_rights_t *rightsp,
280     int needfcntl, struct file **fpp);
281 int _fdrop(struct file *fp, struct thread *td);
282 int fget_remote(struct thread *td, struct proc *p, int fd, struct file **fpp);
283 int fget_remote_foreach(struct thread *td, struct proc *p,
284     int (*fn)(struct proc *, int, struct file *, void *), void *arg);
285 
286 fo_rdwr_t	invfo_rdwr;
287 fo_truncate_t	invfo_truncate;
288 fo_ioctl_t	invfo_ioctl;
289 fo_poll_t	invfo_poll;
290 fo_kqfilter_t	invfo_kqfilter;
291 fo_chmod_t	invfo_chmod;
292 fo_chown_t	invfo_chown;
293 fo_sendfile_t	invfo_sendfile;
294 fo_stat_t	vn_statfile;
295 fo_sendfile_t	vn_sendfile;
296 fo_seek_t	vn_seek;
297 fo_fill_kinfo_t	vn_fill_kinfo;
298 fo_kqfilter_t	vn_kqfilter_opath;
299 int vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif);
300 int file_kcmp_generic(struct file *fp1, struct file *fp2, struct thread *td);
301 
302 void finit(struct file *, u_int, short, void *, const struct fileops *);
303 void finit_vnode(struct file *, u_int, void *, const struct fileops *);
304 int fgetvp(struct thread *td, int fd, const cap_rights_t *rightsp,
305     struct vnode **vpp);
306 int fgetvp_exec(struct thread *td, int fd, const cap_rights_t *rightsp,
307     struct vnode **vpp);
308 int fgetvp_rights(struct thread *td, int fd, const cap_rights_t *needrightsp,
309     struct filecaps *havecaps, struct vnode **vpp);
310 int fgetvp_read(struct thread *td, int fd, const cap_rights_t *rightsp,
311     struct vnode **vpp);
312 int fgetvp_write(struct thread *td, int fd, const cap_rights_t *rightsp,
313     struct vnode **vpp);
314 int fgetvp_lookup_smr(struct nameidata *ndp, struct vnode **vpp, int *flagsp);
315 int fgetvp_lookup(struct nameidata *ndp, struct vnode **vpp);
316 
317 static __inline __result_use_check bool
fhold(struct file * fp)318 fhold(struct file *fp)
319 {
320 	return (refcount_acquire_checked(&fp->f_count));
321 }
322 
323 #define	fdrop(fp, td)		({				\
324 	struct file *_fp;					\
325 	int _error;						\
326 								\
327 	_error = 0;						\
328 	_fp = (fp);						\
329 	if (__predict_false(refcount_release(&_fp->f_count)))	\
330 		_error = _fdrop(_fp, td);			\
331 	_error;							\
332 })
333 
334 #define	fdrop_close(fp, td)		({			\
335 	struct file *_fp;					\
336 	int _error;						\
337 								\
338 	_error = 0;						\
339 	_fp = (fp);						\
340 	if (__predict_true(refcount_release(&_fp->f_count)))	\
341 		_error = _fdrop(_fp, td);			\
342 	_error;							\
343 })
344 
345 static __inline fo_rdwr_t	fo_read;
346 static __inline fo_rdwr_t	fo_write;
347 static __inline fo_truncate_t	fo_truncate;
348 static __inline fo_ioctl_t	fo_ioctl;
349 static __inline fo_poll_t	fo_poll;
350 static __inline fo_kqfilter_t	fo_kqfilter;
351 static __inline fo_stat_t	fo_stat;
352 static __inline fo_close_t	fo_close;
353 static __inline fo_chmod_t	fo_chmod;
354 static __inline fo_chown_t	fo_chown;
355 static __inline fo_sendfile_t	fo_sendfile;
356 
357 static __inline int
fo_read(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)358 fo_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
359     int flags, struct thread *td)
360 {
361 
362 	return ((*fp->f_ops->fo_read)(fp, uio, active_cred, flags, td));
363 }
364 
365 static __inline int
fo_write(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)366 fo_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
367     int flags, struct thread *td)
368 {
369 
370 	return ((*fp->f_ops->fo_write)(fp, uio, active_cred, flags, td));
371 }
372 
373 static __inline int
fo_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)374 fo_truncate(struct file *fp, off_t length, struct ucred *active_cred,
375     struct thread *td)
376 {
377 
378 	return ((*fp->f_ops->fo_truncate)(fp, length, active_cred, td));
379 }
380 
381 static __inline int
fo_ioctl(struct file * fp,u_long com,void * data,struct ucred * active_cred,struct thread * td)382 fo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
383     struct thread *td)
384 {
385 
386 	return ((*fp->f_ops->fo_ioctl)(fp, com, data, active_cred, td));
387 }
388 
389 static __inline int
fo_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)390 fo_poll(struct file *fp, int events, struct ucred *active_cred,
391     struct thread *td)
392 {
393 
394 	return ((*fp->f_ops->fo_poll)(fp, events, active_cred, td));
395 }
396 
397 static __inline int
fo_stat(struct file * fp,struct stat * sb,struct ucred * active_cred)398 fo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
399 {
400 
401 	return ((*fp->f_ops->fo_stat)(fp, sb, active_cred));
402 }
403 
404 static __inline int
fo_close(struct file * fp,struct thread * td)405 fo_close(struct file *fp, struct thread *td)
406 {
407 
408 	return ((*fp->f_ops->fo_close)(fp, td));
409 }
410 
411 static __inline int
fo_kqfilter(struct file * fp,struct knote * kn)412 fo_kqfilter(struct file *fp, struct knote *kn)
413 {
414 
415 	return ((*fp->f_ops->fo_kqfilter)(fp, kn));
416 }
417 
418 static __inline int
fo_chmod(struct file * fp,mode_t mode,struct ucred * active_cred,struct thread * td)419 fo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
420     struct thread *td)
421 {
422 
423 	return ((*fp->f_ops->fo_chmod)(fp, mode, active_cred, td));
424 }
425 
426 static __inline int
fo_chown(struct file * fp,uid_t uid,gid_t gid,struct ucred * active_cred,struct thread * td)427 fo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
428     struct thread *td)
429 {
430 
431 	return ((*fp->f_ops->fo_chown)(fp, uid, gid, active_cred, td));
432 }
433 
434 static __inline int
fo_sendfile(struct file * fp,int sockfd,struct uio * hdr_uio,struct uio * trl_uio,off_t offset,size_t nbytes,off_t * sent,int flags,struct thread * td)435 fo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio,
436     struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags,
437     struct thread *td)
438 {
439 
440 	return ((*fp->f_ops->fo_sendfile)(fp, sockfd, hdr_uio, trl_uio, offset,
441 	    nbytes, sent, flags, td));
442 }
443 
444 static __inline int
fo_seek(struct file * fp,off_t offset,int whence,struct thread * td)445 fo_seek(struct file *fp, off_t offset, int whence, struct thread *td)
446 {
447 
448 	return ((*fp->f_ops->fo_seek)(fp, offset, whence, td));
449 }
450 
451 static __inline int
fo_fill_kinfo(struct file * fp,struct kinfo_file * kif,struct filedesc * fdp)452 fo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
453 {
454 
455 	return ((*fp->f_ops->fo_fill_kinfo)(fp, kif, fdp));
456 }
457 
458 static __inline int
fo_mmap(struct file * fp,vm_map_t map,vm_offset_t * addr,vm_size_t size,vm_prot_t prot,vm_prot_t cap_maxprot,int flags,vm_ooffset_t foff,struct thread * td)459 fo_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
460     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
461     struct thread *td)
462 {
463 
464 	if (fp->f_ops->fo_mmap == NULL)
465 		return (ENODEV);
466 	return ((*fp->f_ops->fo_mmap)(fp, map, addr, size, prot, cap_maxprot,
467 	    flags, foff, td));
468 }
469 
470 static __inline int
fo_aio_queue(struct file * fp,struct kaiocb * job)471 fo_aio_queue(struct file *fp, struct kaiocb *job)
472 {
473 
474 	return ((*fp->f_ops->fo_aio_queue)(fp, job));
475 }
476 
477 static __inline int
fo_add_seals(struct file * fp,int seals)478 fo_add_seals(struct file *fp, int seals)
479 {
480 
481 	if (fp->f_ops->fo_add_seals == NULL)
482 		return (EINVAL);
483 	return ((*fp->f_ops->fo_add_seals)(fp, seals));
484 }
485 
486 static __inline int
fo_get_seals(struct file * fp,int * seals)487 fo_get_seals(struct file *fp, int *seals)
488 {
489 
490 	if (fp->f_ops->fo_get_seals == NULL)
491 		return (EINVAL);
492 	return ((*fp->f_ops->fo_get_seals)(fp, seals));
493 }
494 
495 static __inline int
fo_fallocate(struct file * fp,off_t offset,off_t len,struct thread * td)496 fo_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
497 {
498 
499 	if (fp->f_ops->fo_fallocate == NULL)
500 		return (ENODEV);
501 	return ((*fp->f_ops->fo_fallocate)(fp, offset, len, td));
502 }
503 
504 static __inline int
fo_fspacectl(struct file * fp,int cmd,off_t * offset,off_t * length,int flags,struct ucred * active_cred,struct thread * td)505 fo_fspacectl(struct file *fp, int cmd, off_t *offset, off_t *length,
506     int flags, struct ucred *active_cred, struct thread *td)
507 {
508 
509 	if (fp->f_ops->fo_fspacectl == NULL)
510 		return (ENODEV);
511 	return ((*fp->f_ops->fo_fspacectl)(fp, cmd, offset, length, flags,
512 	    active_cred, td));
513 }
514 
515 static __inline int
fo_cmp(struct file * fp1,struct file * fp2,struct thread * td)516 fo_cmp(struct file *fp1, struct file *fp2, struct thread *td)
517 {
518 
519 	if (fp1->f_ops->fo_cmp == NULL)
520 		return (ENODEV);
521 	return ((*fp1->f_ops->fo_cmp)(fp1, fp2, td));
522 }
523 
524 #endif /* _KERNEL */
525 
526 #endif /* !SYS_FILE_H */
527