xref: /xnu-11215.41.3/bsd/miscfs/deadfs/dead_vnops.c (revision 33de042d024d46de5ff4e89f2471de6608e37fa4)
1 /*
2  * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Copyright (c) 1989, 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. All advertising materials mentioning features or use of this software
42  *    must display the following acknowledgement:
43  *	This product includes software developed by the University of
44  *	California, Berkeley and its contributors.
45  * 4. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)dead_vnops.c	8.3 (Berkeley) 5/14/95
62  */
63 
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/time.h>
67 #include <sys/vnode_internal.h>
68 #include <sys/buf_internal.h>
69 #include <sys/errno.h>
70 #include <sys/namei.h>
71 #include <sys/buf.h>
72 #include <vfs/vfs_support.h>
73 
74 int     chkvnlock(vnode_t vp);
75 
76 /*
77  * Prototypes for dead operations on vnodes.
78  */
79 int     dead_badop(void *);
80 int     dead_ebadf(void *);
81 int     dead_lookup(struct vnop_lookup_args *);
82 int     dead_open(struct vnop_open_args *);
83 #define dead_access (int (*)(struct  vnop_access_args *))dead_ebadf
84 #define dead_getattr (int (*)(struct  vnop_getattr_args *))dead_ebadf
85 #define dead_setattr (int (*)(struct  vnop_setattr_args *))dead_ebadf
86 int     dead_read(struct vnop_read_args *);
87 int     dead_write(struct vnop_write_args *);
88 int     dead_ioctl(struct vnop_ioctl_args *);
89 int     dead_select(struct vnop_select_args *);
90 #define dead_readdir (int (*)(struct  vnop_readdir_args *))dead_ebadf
91 #define dead_readlink (int (*)(struct  vnop_readlink_args *))dead_ebadf
92 int     dead_strategy(struct vnop_strategy_args *);
93 int     dead_bwrite(struct vnop_bwrite_args *);
94 #define dead_pathconf (int (*)(struct  vnop_pathconf_args *))dead_ebadf
95 #define dead_advlock (int (*)(struct  vnop_advlock_args *))dead_ebadf
96 int     dead_pagein(struct vnop_pagein_args *);
97 int     dead_pageout(struct vnop_pageout_args *);
98 int dead_blktooff(struct vnop_blktooff_args *);
99 int dead_offtoblk(struct vnop_offtoblk_args *);
100 int dead_blockmap(struct vnop_blockmap_args *);
101 
102 #define dead_nullop (void (*)(void))nullop
103 
104 #define VOPFUNC int (*)(void *)
105 int(**dead_vnodeop_p)(void *);
106 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
107 	{ .opve_op = &vnop_default_desc, .opve_impl = (VOPFUNC)(void (*)(void ))vn_default_error },
108 	{ .opve_op = &vnop_lookup_desc, .opve_impl = (VOPFUNC)dead_lookup },    /* lookup */
109 	{ .opve_op = &vnop_create_desc, .opve_impl = (VOPFUNC)dead_badop },    /* create */
110 	{ .opve_op = &vnop_open_desc, .opve_impl = (VOPFUNC)dead_open },                /* open */
111 	{ .opve_op = &vnop_mknod_desc, .opve_impl = (VOPFUNC)dead_badop },              /* mknod */
112 	{ .opve_op = &vnop_close_desc, .opve_impl = (VOPFUNC)dead_nullop },      /* close */
113 	{ .opve_op = &vnop_access_desc, .opve_impl = (VOPFUNC)dead_access },    /* access */
114 	{ .opve_op = &vnop_getattr_desc, .opve_impl = (VOPFUNC)dead_getattr },  /* getattr */
115 	{ .opve_op = &vnop_setattr_desc, .opve_impl = (VOPFUNC)dead_setattr },  /* setattr */
116 	{ .opve_op = &vnop_read_desc, .opve_impl = (VOPFUNC)dead_read },                /* read */
117 	{ .opve_op = &vnop_write_desc, .opve_impl = (VOPFUNC)dead_write },      /* write */
118 	{ .opve_op = &vnop_ioctl_desc, .opve_impl = (VOPFUNC)dead_ioctl },      /* ioctl */
119 	{ .opve_op = &vnop_select_desc, .opve_impl = (VOPFUNC)dead_select },    /* select */
120 	{ .opve_op = &vnop_mmap_desc, .opve_impl = (VOPFUNC)dead_badop },                /* mmap */
121 	{ .opve_op = &vnop_fsync_desc, .opve_impl = (VOPFUNC)dead_nullop},      /* fsync */
122 	{ .opve_op = &vnop_remove_desc, .opve_impl = (VOPFUNC)dead_badop },    /* remove */
123 	{ .opve_op = &vnop_link_desc, .opve_impl = (VOPFUNC)dead_badop },                /* link */
124 	{ .opve_op = &vnop_rename_desc, .opve_impl = (VOPFUNC)dead_badop },    /* rename */
125 	{ .opve_op = &vnop_mkdir_desc, .opve_impl = (VOPFUNC)dead_badop },      /* mkdir */
126 	{ .opve_op = &vnop_rmdir_desc, .opve_impl = (VOPFUNC)dead_badop },      /* rmdir */
127 	{ .opve_op = &vnop_symlink_desc, .opve_impl = (VOPFUNC)dead_badop },  /* symlink */
128 	{ .opve_op = &vnop_readdir_desc, .opve_impl = (VOPFUNC)dead_readdir },  /* readdir */
129 	{ .opve_op = &vnop_readlink_desc, .opve_impl = (VOPFUNC)dead_readlink },        /* readlink */
130 	{ .opve_op = &vnop_inactive_desc, .opve_impl = (VOPFUNC)dead_nullop },        /* inactive */
131 	{ .opve_op = &vnop_reclaim_desc, .opve_impl = (VOPFUNC)dead_nullop },  /* reclaim */
132 	{ .opve_op = &vnop_strategy_desc, .opve_impl = (VOPFUNC)dead_strategy },        /* strategy */
133 	{ .opve_op = &vnop_pathconf_desc, .opve_impl = (VOPFUNC)dead_pathconf },        /* pathconf */
134 	{ .opve_op = &vnop_advlock_desc, .opve_impl = (VOPFUNC)dead_advlock },  /* advlock */
135 	{ .opve_op = &vnop_bwrite_desc, .opve_impl = (VOPFUNC)dead_bwrite },    /* bwrite */
136 	{ .opve_op = &vnop_pagein_desc, .opve_impl = (VOPFUNC)err_pagein },     /* Pagein */
137 	{ .opve_op = &vnop_pageout_desc, .opve_impl = (VOPFUNC)err_pageout },   /* Pageout */
138 	{ .opve_op = &vnop_copyfile_desc, .opve_impl = (VOPFUNC)err_copyfile }, /* Copyfile */
139 	{ .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)dead_blktooff },        /* blktooff */
140 	{ .opve_op = &vnop_offtoblk_desc, .opve_impl = (VOPFUNC)dead_offtoblk },        /* offtoblk */
141 	{ .opve_op = &vnop_blockmap_desc, .opve_impl = (VOPFUNC)dead_blockmap },                /* blockmap */
142 	{ .opve_op = (struct vnodeop_desc*)NULL, .opve_impl = (VOPFUNC)NULL }
143 };
144 const struct vnodeopv_desc dead_vnodeop_opv_desc =
145 { .opv_desc_vector_p = &dead_vnodeop_p, .opv_desc_ops = dead_vnodeop_entries };
146 
147 /*
148  * Trivial lookup routine that always fails.
149  */
150 /* ARGSUSED */
151 int
dead_lookup(struct vnop_lookup_args * ap)152 dead_lookup(struct vnop_lookup_args *ap)
153 {
154 	*ap->a_vpp = NULL;
155 	return ENOTDIR;
156 }
157 
158 /*
159  * Open always fails as if device did not exist.
160  */
161 /* ARGSUSED */
162 int
dead_open(__unused struct vnop_open_args * ap)163 dead_open(__unused struct vnop_open_args *ap)
164 {
165 	return ENXIO;
166 }
167 
168 /*
169  * Vnode op for read
170  */
171 /* ARGSUSED */
172 int
dead_read(struct vnop_read_args * ap)173 dead_read(struct vnop_read_args *ap)
174 {
175 	if (chkvnlock(ap->a_vp)) {
176 		panic("dead_read: lock");
177 	}
178 	/*
179 	 * Return EOF for character devices, EIO for others
180 	 */
181 	if (ap->a_vp->v_type != VCHR) {
182 		return EIO;
183 	}
184 	return 0;
185 }
186 
187 /*
188  * Vnode op for write
189  */
190 /* ARGSUSED */
191 int
dead_write(struct vnop_write_args * ap)192 dead_write(struct vnop_write_args *ap)
193 {
194 	if (chkvnlock(ap->a_vp)) {
195 		panic("dead_write: lock");
196 	}
197 	return EIO;
198 }
199 
200 /*
201  * Device ioctl operation.
202  */
203 /* ARGSUSED */
204 int
dead_ioctl(struct vnop_ioctl_args * ap)205 dead_ioctl(struct vnop_ioctl_args *ap)
206 {
207 	if (!chkvnlock(ap->a_vp)) {
208 		return EBADF;
209 	}
210 	return VCALL(ap->a_vp, VOFFSET(vnop_ioctl), ap);
211 }
212 
213 /* ARGSUSED */
214 int
dead_select(__unused struct vnop_select_args * ap)215 dead_select(__unused struct vnop_select_args *ap)
216 {
217 	/*
218 	 * Let the user find out that the descriptor is gone.
219 	 */
220 	return 1;
221 }
222 
223 /*
224  * Just call the device strategy routine
225  */
226 int
dead_strategy(struct vnop_strategy_args * ap)227 dead_strategy(struct vnop_strategy_args *ap)
228 {
229 	vnode_t vp = buf_vnop_vnode(ap->a_bp);
230 
231 	if (!vp || !chkvnlock(vp)) {
232 		if (vp) {
233 			vnode_lock(vp);
234 			if (!(vp->v_lflag & VL_DEAD) || vp->v_op != dead_vnodeop_p) {
235 #if DEVELOPMENT || DEBUG
236 				panic("%s: vnode %p (v_lflag 0x%x) is NOT in dead state",
237 				    __func__, vp, vp->v_lflag);
238 #else
239 				printf("%s: vnode %p (v_lflag 0x%x) is NOT in dead state",
240 				    __func__, vp, vp->v_lflag);
241 #endif
242 			}
243 			vnode_unlock(vp);
244 			printf("%s: returning EIO for vnode v_flags = 0x%x v_numoutput = %d\n",
245 			    __func__, vp->v_flag, vp->v_numoutput);
246 		}
247 		buf_seterror(ap->a_bp, EIO);
248 		buf_biodone(ap->a_bp);
249 		return EIO;
250 	}
251 
252 	printf("%s: vnode is going to call the original bwrite routine v_lflag 0x%x v_flags = 0x%x v_numoutput = %d\n",
253 	    __func__, vp->v_lflag, vp->v_flag, vp->v_numoutput);
254 
255 	return VOCALL(vp->v_op, VOFFSET(vnop_strategy), ap);
256 }
257 
258 /*
259  * Return an error and complete the IO if the vnode is not changing state.
260  */
261 int
dead_bwrite(struct vnop_bwrite_args * ap)262 dead_bwrite(struct vnop_bwrite_args *ap)
263 {
264 	buf_t bp = ap->a_bp;
265 	vnode_t vp = buf_vnop_vnode(bp);
266 
267 	if (!vp || !chkvnlock(vp)) {
268 		vnode_t buf_vp = buf_vnode(bp);
269 
270 		if (vp) {
271 			vnode_lock(vp);
272 			if (!(vp->v_lflag & VL_DEAD) || vp->v_op != dead_vnodeop_p) {
273 #if DEVELOPMENT || DEBUG
274 				panic("%s: vnode %p (v_lflag 0x%x) is NOT in dead state",
275 				    __func__, vp, vp->v_lflag);
276 #else
277 				printf("%s: vnode %p (v_lflag 0x%x) is NOT in dead state",
278 				    __func__, vp, vp->v_lflag);
279 #endif
280 			}
281 			vnode_unlock(vp);
282 		}
283 
284 		buf_seterror(bp, EIO);
285 
286 		if (buf_vp) {
287 			/*
288 			 * buf_biodone is expecting this to be incremented (see buf_bwrite)
289 			 */
290 			OSAddAtomic(1, &buf_vp->v_numoutput);
291 			printf("%s: returning EIO for vnode v_flags = 0x%x v_numoutput = %d\n",
292 			    __func__, buf_vp->v_flag, buf_vp->v_numoutput);
293 		}
294 		buf_biodone(bp);
295 		return EIO;
296 	}
297 
298 	printf("%s: vnode is going to call the original bwrite routine v_lflag 0x%x v_flags = 0x%x v_numoutput = %d\n",
299 	    __func__, vp->v_lflag, vp->v_flag, vp->v_numoutput);
300 
301 	return VOCALL(vp->v_op, VOFFSET(vnop_bwrite), ap);
302 }
303 
304 /*
305  * Wait until the vnode has finished changing state.
306  */
307 int
dead_blockmap(struct vnop_blockmap_args * ap)308 dead_blockmap(struct vnop_blockmap_args *ap)
309 {
310 	if (!chkvnlock(ap->a_vp)) {
311 		return EIO;
312 	}
313 	return VNOP_BLOCKMAP(ap->a_vp, ap->a_foffset, ap->a_size, ap->a_bpn,
314 	           ap->a_run, ap->a_poff, ap->a_flags, ap->a_context);
315 }
316 
317 /*
318  * Empty vnode failed operation
319  */
320 /* ARGSUSED */
321 int
dead_ebadf(__unused void * dummy)322 dead_ebadf(__unused void *dummy)
323 {
324 	return EBADF;
325 }
326 
327 /*
328  * Empty vnode bad operation
329  */
330 /* ARGSUSED */
331 int
dead_badop(__unused void * dummy)332 dead_badop(__unused void *dummy)
333 {
334 	panic("dead_badop called");
335 	/* NOTREACHED */
336 	return -1;
337 }
338 
339 /*
340  * We have to wait during times when the vnode is
341  * in a state of change.
342  */
343 int
chkvnlock(vnode_t vp)344 chkvnlock(vnode_t vp)
345 {
346 	vnode_lock(vp);
347 	if (!(vp->v_lflag & VL_OPSCHANGE)) {
348 		vnode_unlock(vp);
349 		return 0;
350 	}
351 	while (vp->v_lflag & VL_DEAD) {
352 		msleep(&vp->v_lflag, &vp->v_lock, PVFS, "chkvnlock", NULL);
353 	}
354 	vnode_unlock(vp);
355 	return 1;
356 }
357 
358 
359 /* Blktooff */
360 int
dead_blktooff(struct vnop_blktooff_args * ap)361 dead_blktooff(struct vnop_blktooff_args *ap)
362 {
363 	if (!chkvnlock(ap->a_vp)) {
364 		return EIO;
365 	}
366 
367 	*ap->a_offset = (off_t)-1;      /* failure */
368 	return 0;
369 }
370 /* Blktooff */
371 int
dead_offtoblk(struct vnop_offtoblk_args * ap)372 dead_offtoblk(struct vnop_offtoblk_args *ap)
373 {
374 	if (!chkvnlock(ap->a_vp)) {
375 		return EIO;
376 	}
377 
378 	*ap->a_lblkno = (daddr64_t)-1;  /* failure */
379 	return 0;
380 }
381