xref: /freebsd/sys/fs/deadfs/dead_vnops.c (revision 0de89efe5c443f213c7ea28773ef2dc6cf3af2ed)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)dead_vnops.c	8.1 (Berkeley) 6/10/93
34  * $Id: dead_vnops.c,v 1.14 1997/09/02 20:06:08 bde Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/vnode.h>
41 #include <sys/buf.h>
42 
43 static int	chkvnlock __P((struct vnode *));
44 /*
45  * Prototypes for dead operations on vnodes.
46  */
47 static int	dead_badop __P((void));
48 static int	dead_ebadf __P((void));
49 static int	dead_lookup __P((struct vop_lookup_args *));
50 #define dead_create ((int (*) __P((struct  vop_create_args *)))dead_badop)
51 #define dead_mknod ((int (*) __P((struct  vop_mknod_args *)))dead_badop)
52 static int	dead_open __P((struct vop_open_args *));
53 #define dead_close ((int (*) __P((struct  vop_close_args *)))nullop)
54 #define dead_access ((int (*) __P((struct  vop_access_args *)))dead_ebadf)
55 #define dead_getattr ((int (*) __P((struct  vop_getattr_args *)))dead_ebadf)
56 #define dead_setattr ((int (*) __P((struct  vop_setattr_args *)))dead_ebadf)
57 static int	dead_read __P((struct vop_read_args *));
58 static int	dead_write __P((struct vop_write_args *));
59 static int	dead_ioctl __P((struct vop_ioctl_args *));
60 #define dead_poll vop_nopoll
61 #define dead_mmap ((int (*) __P((struct  vop_mmap_args *)))dead_badop)
62 #define dead_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
63 #define dead_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
64 #define dead_remove ((int (*) __P((struct  vop_remove_args *)))dead_badop)
65 #define dead_link ((int (*) __P((struct  vop_link_args *)))dead_badop)
66 #define dead_rename ((int (*) __P((struct  vop_rename_args *)))dead_badop)
67 #define dead_mkdir ((int (*) __P((struct  vop_mkdir_args *)))dead_badop)
68 #define dead_rmdir ((int (*) __P((struct  vop_rmdir_args *)))dead_badop)
69 #define dead_symlink ((int (*) __P((struct  vop_symlink_args *)))dead_badop)
70 #define dead_readdir ((int (*) __P((struct  vop_readdir_args *)))dead_ebadf)
71 #define dead_readlink ((int (*) __P((struct  vop_readlink_args *)))dead_ebadf)
72 #define dead_abortop ((int (*) __P((struct  vop_abortop_args *)))dead_badop)
73 #define dead_inactive ((int (*) __P((struct  vop_inactive_args *)))nullop)
74 #define dead_reclaim ((int (*) __P((struct  vop_reclaim_args *)))nullop)
75 static int	dead_lock __P((struct vop_lock_args *));
76 #define dead_unlock ((int (*) __P((struct vop_unlock_args *)))vop_nounlock)
77 static int	dead_bmap __P((struct vop_bmap_args *));
78 static int	dead_strategy __P((struct vop_strategy_args *));
79 static int	dead_print __P((struct vop_print_args *));
80 #define dead_islocked ((int(*) __P((struct vop_islocked_args *)))vop_noislocked)
81 #define dead_pathconf ((int (*) __P((struct  vop_pathconf_args *)))dead_ebadf)
82 #define dead_advlock ((int (*) __P((struct  vop_advlock_args *)))dead_ebadf)
83 #define dead_blkatoff ((int (*) __P((struct  vop_blkatoff_args *)))dead_badop)
84 #define dead_valloc ((int (*) __P((struct  vop_valloc_args *)))dead_badop)
85 #define dead_vfree ((int (*) __P((struct  vop_vfree_args *)))dead_badop)
86 #define dead_truncate ((int (*) __P((struct  vop_truncate_args *)))nullop)
87 #define dead_update ((int (*) __P((struct  vop_update_args *)))nullop)
88 #define dead_bwrite ((int (*) __P((struct  vop_bwrite_args *)))nullop)
89 
90 vop_t **dead_vnodeop_p;
91 static struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
92 	{ &vop_default_desc, (vop_t *)vn_default_error },
93 	{ &vop_lookup_desc, (vop_t *)dead_lookup },	/* lookup */
94 /* XXX: vop_cachedlookup */
95 	{ &vop_create_desc, (vop_t *)dead_create },	/* create */
96 /* XXX: vop_whiteout */
97 	{ &vop_mknod_desc, (vop_t *)dead_mknod },	/* mknod */
98 	{ &vop_open_desc, (vop_t *)dead_open },		/* open */
99 	{ &vop_close_desc, (vop_t *)dead_close },	/* close */
100 	{ &vop_access_desc, (vop_t *)dead_access },	/* access */
101 	{ &vop_getattr_desc, (vop_t *)dead_getattr },	/* getattr */
102 	{ &vop_setattr_desc, (vop_t *)dead_setattr },	/* setattr */
103 	{ &vop_read_desc, (vop_t *)dead_read },		/* read */
104 	{ &vop_write_desc, (vop_t *)dead_write },	/* write */
105 /* XXX: vop_lease */
106 	{ &vop_ioctl_desc, (vop_t *)dead_ioctl },	/* ioctl */
107 	{ &vop_poll_desc, (vop_t *)dead_poll },		/* poll */
108 /* XXX: vop_revoke */
109 	{ &vop_mmap_desc, (vop_t *)dead_mmap },		/* mmap */
110 	{ &vop_fsync_desc, (vop_t *)dead_fsync },	/* fsync */
111 	{ &vop_seek_desc, (vop_t *)dead_seek },		/* seek */
112 	{ &vop_remove_desc, (vop_t *)dead_remove },	/* remove */
113 	{ &vop_link_desc, (vop_t *)dead_link },		/* link */
114 	{ &vop_rename_desc, (vop_t *)dead_rename },	/* rename */
115 	{ &vop_mkdir_desc, (vop_t *)dead_mkdir },	/* mkdir */
116 	{ &vop_rmdir_desc, (vop_t *)dead_rmdir },	/* rmdir */
117 	{ &vop_symlink_desc, (vop_t *)dead_symlink },	/* symlink */
118 	{ &vop_readdir_desc, (vop_t *)dead_readdir },	/* readdir */
119 	{ &vop_readlink_desc, (vop_t *)dead_readlink },	/* readlink */
120 	{ &vop_abortop_desc, (vop_t *)dead_abortop },	/* abortop */
121 	{ &vop_inactive_desc, (vop_t *)dead_inactive },	/* inactive */
122 	{ &vop_reclaim_desc, (vop_t *)dead_reclaim },	/* reclaim */
123 	{ &vop_lock_desc, (vop_t *)dead_lock },		/* lock */
124 	{ &vop_unlock_desc, (vop_t *)dead_unlock },	/* unlock */
125 	{ &vop_bmap_desc, (vop_t *)dead_bmap },		/* bmap */
126 	{ &vop_strategy_desc, (vop_t *)dead_strategy },	/* strategy */
127 	{ &vop_print_desc, (vop_t *)dead_print },	/* print */
128 	{ &vop_islocked_desc, (vop_t *)dead_islocked },	/* islocked */
129 	{ &vop_pathconf_desc, (vop_t *)dead_pathconf },	/* pathconf */
130 	{ &vop_advlock_desc, (vop_t *)dead_advlock },	/* advlock */
131 	{ &vop_blkatoff_desc, (vop_t *)dead_blkatoff },	/* blkatoff */
132 	{ &vop_valloc_desc, (vop_t *)dead_valloc },	/* valloc */
133 /* XXX: vop_reallocblks */
134 	{ &vop_vfree_desc, (vop_t *)dead_vfree },	/* vfree */
135 	{ &vop_truncate_desc, (vop_t *)dead_truncate },	/* truncate */
136 	{ &vop_update_desc, (vop_t *)dead_update },	/* update */
137 /* XXX: vop_getpages */
138 /* XXX: vop_putpages */
139 	{ &vop_bwrite_desc, (vop_t *)dead_bwrite },	/* bwrite */
140 	{ NULL, NULL }
141 };
142 static struct vnodeopv_desc dead_vnodeop_opv_desc =
143 	{ &dead_vnodeop_p, dead_vnodeop_entries };
144 
145 VNODEOP_SET(dead_vnodeop_opv_desc);
146 
147 /*
148  * Trivial lookup routine that always fails.
149  */
150 /* ARGSUSED */
151 static int
152 dead_lookup(ap)
153 	struct vop_lookup_args /* {
154 		struct vnode * a_dvp;
155 		struct vnode ** a_vpp;
156 		struct componentname * a_cnp;
157 	} */ *ap;
158 {
159 
160 	*ap->a_vpp = NULL;
161 	return (ENOTDIR);
162 }
163 
164 /*
165  * Open always fails as if device did not exist.
166  */
167 /* ARGSUSED */
168 static int
169 dead_open(ap)
170 	struct vop_open_args /* {
171 		struct vnode *a_vp;
172 		int  a_mode;
173 		struct ucred *a_cred;
174 		struct proc *a_p;
175 	} */ *ap;
176 {
177 
178 	return (ENXIO);
179 }
180 
181 /*
182  * Vnode op for read
183  */
184 /* ARGSUSED */
185 static int
186 dead_read(ap)
187 	struct vop_read_args /* {
188 		struct vnode *a_vp;
189 		struct uio *a_uio;
190 		int  a_ioflag;
191 		struct ucred *a_cred;
192 	} */ *ap;
193 {
194 
195 	if (chkvnlock(ap->a_vp))
196 		panic("dead_read: lock");
197 #if 0
198 	/* Lite2 behaviour */
199 	/*
200 	 * Return EOF for tty devices, EIO for others
201 	 */
202 	if ((ap->a_vp->v_flag & VISTTY) == 0)
203 		return (EIO);
204 #else
205 	/*
206 	 * Return EOF for character devices, EIO for others
207 	 */
208 	if (ap->a_vp->v_type != VCHR)
209 		return (EIO);
210 #endif
211 	return (0);
212 }
213 
214 /*
215  * Vnode op for write
216  */
217 /* ARGSUSED */
218 static int
219 dead_write(ap)
220 	struct vop_write_args /* {
221 		struct vnode *a_vp;
222 		struct uio *a_uio;
223 		int  a_ioflag;
224 		struct ucred *a_cred;
225 	} */ *ap;
226 {
227 
228 	if (chkvnlock(ap->a_vp))
229 		panic("dead_write: lock");
230 	return (EIO);
231 }
232 
233 /*
234  * Device ioctl operation.
235  */
236 /* ARGSUSED */
237 static int
238 dead_ioctl(ap)
239 	struct vop_ioctl_args /* {
240 		struct vnode *a_vp;
241 		int  a_command;
242 		caddr_t  a_data;
243 		int  a_fflag;
244 		struct ucred *a_cred;
245 		struct proc *a_p;
246 	} */ *ap;
247 {
248 
249 	if (!chkvnlock(ap->a_vp))
250 		return (EBADF);
251 	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
252 }
253 
254 /*
255  * Just call the device strategy routine
256  */
257 static int
258 dead_strategy(ap)
259 	struct vop_strategy_args /* {
260 		struct buf *a_bp;
261 	} */ *ap;
262 {
263 
264 	if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
265 		ap->a_bp->b_flags |= B_ERROR;
266 		biodone(ap->a_bp);
267 		return (EIO);
268 	}
269 	return (VOP_STRATEGY(ap->a_bp));
270 }
271 
272 /*
273  * Wait until the vnode has finished changing state.
274  */
275 static int
276 dead_lock(ap)
277 	struct vop_lock_args /* {
278 		struct vnode *a_vp;
279 		int a_flags;
280 		struct proc *a_p;
281 	} */ *ap;
282 {
283 	struct vnode *vp = ap->a_vp;
284 
285 	/*
286 	 * Since we are not using the lock manager, we must clear
287 	 * the interlock here.
288 	 */
289 	if (ap->a_flags & LK_INTERLOCK) {
290 		simple_unlock(&vp->v_interlock);
291 		ap->a_flags &= ~LK_INTERLOCK;
292 	}
293 	if (!chkvnlock(vp))
294 		return (0);
295 	return (VCALL(vp, VOFFSET(vop_lock), ap));
296 }
297 
298 /*
299  * Wait until the vnode has finished changing state.
300  */
301 static int
302 dead_bmap(ap)
303 	struct vop_bmap_args /* {
304 		struct vnode *a_vp;
305 		daddr_t  a_bn;
306 		struct vnode **a_vpp;
307 		daddr_t *a_bnp;
308 		int *a_runp;
309 		int *a_runb;
310 	} */ *ap;
311 {
312 
313 	if (!chkvnlock(ap->a_vp))
314 		return (EIO);
315 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp, ap->a_runb));
316 }
317 
318 /*
319  * Print out the contents of a dead vnode.
320  */
321 /* ARGSUSED */
322 static int
323 dead_print(ap)
324 	struct vop_print_args /* {
325 		struct vnode *a_vp;
326 	} */ *ap;
327 {
328 
329 	printf("tag VT_NON, dead vnode\n");
330 	return (0);
331 }
332 
333 /*
334  * Empty vnode failed operation
335  */
336 static int
337 dead_ebadf()
338 {
339 
340 	return (EBADF);
341 }
342 
343 /*
344  * Empty vnode bad operation
345  */
346 static int
347 dead_badop()
348 {
349 
350 	panic("dead_badop called");
351 	/* NOTREACHED */
352 }
353 
354 /*
355  * We have to wait during times when the vnode is
356  * in a state of change.
357  */
358 int
359 chkvnlock(vp)
360 	register struct vnode *vp;
361 {
362 	int locked = 0;
363 
364 	while (vp->v_flag & VXLOCK) {
365 		vp->v_flag |= VXWANT;
366 		(void) tsleep((caddr_t)vp, PINOD, "ckvnlk", 0);
367 		locked = 1;
368 	}
369 	return (locked);
370 }
371