summaryrefslogtreecommitdiffstats
path: root/sys/kern/vfs_init.c
blob: c6aaacbc19dfc70334b0c2a33c4c2ca284155013 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed
 * to Berkeley by John Heidemann of the UCLA Ficus project.
 *
 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)vfs_init.c	8.3 (Berkeley) 1/4/94
 * $Id: vfs_init.c,v 1.31 1997/10/26 20:26:33 phk Exp $
 */


#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <vm/vm_zone.h>

static void	vfs_op_init __P((void));

static void vfsinit __P((void *));
SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_FIRST, vfsinit, NULL)

MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes");

/*
 * Sigh, such primitive tools are these...
 */
#if 0
#define DODEBUG(A) A
#else
#define DODEBUG(A)
#endif

static struct vfsconf void_vfsconf;

extern struct linker_set vfs_opv_descs_;
#define vfs_opv_descs ((struct vnodeopv_desc **)vfs_opv_descs_.ls_items)

extern struct linker_set vfs_set;

extern struct vnodeop_desc *vfs_op_descs[];
				/* and the operations they perform */

/*
 * Zone for namei
 */
struct vm_zone *namei_zone;

/*
 * vfs_init.c
 *
 * Allocate and fill in operations vectors.
 *
 * An undocumented feature of this approach to defining operations is that
 * there can be multiple entries in vfs_opv_descs for the same operations
 * vector. This allows third parties to extend the set of operations
 * supported by another layer in a binary compatibile way. For example,
 * assume that NFS needed to be modified to support Ficus. NFS has an entry
 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
 * listing those new operations Ficus adds to NFS, all without modifying the
 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
 * that is a(whole)nother story.) This is a feature.
 *
 * Without an explicit reserve area, however, you must replace vnode_if.c
 * and vnode_if.h when you do this, or you will be derefrencing of the
 * end of vfs_op_descs[].  This is a flaw in the use of a structure
 * pointer array rather than an agregate to define vfs_op_descs.  So
 * it's not a very dynamic "feature".
 */
void
vfs_opv_init(struct vnodeopv_desc **them)
{
	int i, j, k;
	vop_t ***opv_desc_vector_p;
	vop_t **opv_desc_vector;
	struct vnodeopv_entry_desc *opve_descp;

	/*
	 * Allocate the dynamic vectors and fill them in.
	 */
	for (i=0; them[i]; i++) {
		opv_desc_vector_p = them[i]->opv_desc_vector_p;
		/*
		 * Allocate and init the vector, if it needs it.
		 * Also handle backwards compatibility.
		 */
		if (*opv_desc_vector_p == NULL) {
			/* XXX - shouldn't be M_VNODE */
			MALLOC(*opv_desc_vector_p, vop_t **,
			       vfs_opv_numops * sizeof(vop_t *), M_VNODE,
			       M_WAITOK);
			bzero(*opv_desc_vector_p,
			      vfs_opv_numops * sizeof(vop_t *));
			DODEBUG(printf("vector at %x allocated\n",
			    opv_desc_vector_p));
		}
		opv_desc_vector = *opv_desc_vector_p;
		for (j=0; them[i]->opv_desc_ops[j].opve_op; j++) {
			opve_descp = &(them[i]->opv_desc_ops[j]);

			/*
			 * Sanity check:  is this operation listed
			 * in the list of operations?  We check this
			 * by seeing if its offest is zero.  Since
			 * the default routine should always be listed
			 * first, it should be the only one with a zero
			 * offset.  Any other operation with a zero
			 * offset is probably not listed in
			 * vfs_op_descs, and so is probably an error.
			 *
			 * A panic here means the layer programmer
			 * has committed the all-too common bug
			 * of adding a new operation to the layer's
			 * list of vnode operations but
			 * not adding the operation to the system-wide
			 * list of supported operations.
			 */
			if (opve_descp->opve_op->vdesc_offset == 0 &&
				    opve_descp->opve_op->vdesc_offset !=
				    	VOFFSET(vop_default)) {
				printf("operation %s not listed in %s.\n",
				    opve_descp->opve_op->vdesc_name,
				    "vfs_op_descs");
				panic ("vfs_opv_init: bad operation");
			}
			/*
			 * Fill in this entry.
			 */
			opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
					opve_descp->opve_impl;
		}
	}
	/*
	 * Finally, go back and replace unfilled routines
	 * with their default.  (Sigh, an O(n^3) algorithm.  I
	 * could make it better, but that'd be work, and n is small.)
	 */
	for (i = 0; them[i]; i++) {
		opv_desc_vector = *(them[i]->opv_desc_vector_p);
		/*
		 * Force every operations vector to have a default routine.
		 */
		if (opv_desc_vector[VOFFSET(vop_default)]==NULL) {
			panic("vfs_opv_init: operation vector without default routine.");
		}
		for (k = 0; k<vfs_opv_numops; k++)
			if (opv_desc_vector[k] == NULL)
				opv_desc_vector[k] =
					opv_desc_vector[VOFFSET(vop_default)];
	}
}

/*
 * Initialize known vnode operations vectors.
 */
static void
vfs_op_init()
{
	int i;

	DODEBUG(printf("Vnode_interface_init.\n"));
	DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops));
	/*
	 * Set all vnode vectors to a well known value.
	 */
	for (i = 0; vfs_opv_descs[i]; i++)
		*(vfs_opv_descs[i]->opv_desc_vector_p) = NULL;
	/*
	 * assign each op to its offset
	 *
	 * XXX This should not be needed, but is because the per
	 * XXX FS ops tables are not sorted according to the
	 * XXX vnodeop_desc's offset in vfs_op_descs.  This
	 * XXX is the same reason we have to take the hit for
	 * XXX the static inline function calls instead of using
	 * XXX simple macro references.
	 */
	for (i = 0; i < vfs_opv_numops; i++)
		vfs_op_descs[i]->vdesc_offset = i;
}

/*
 * Routines having to do with the management of the vnode table.
 */
extern struct vnodeops dead_vnodeops;
extern struct vnodeops spec_vnodeops;
struct vattr va_null;

/*
 * Initialize the vnode structures and initialize each file system type.
 */
/* ARGSUSED*/
static void
vfsinit(dummy)
	void *dummy;
{
	struct vfsconf **vfc;
	int maxtypenum;

	namei_zone = zinit("NAMEI", MAXPATHLEN, 0, 0, 2);

	/*
	 * Initialize the vnode table
	 */
	vntblinit();
	/*
	 * Initialize the vnode name cache
	 */
	nchinit();
	/*
	 * Build vnode operation vectors.
	 */
	vfs_op_init();
	vfs_opv_init(vfs_opv_descs);   /* finish the job */
	/*
	 * Initialize each file system type.
	 */
	vattr_null(&va_null);
	maxtypenum = 0;
	vfc = (struct vfsconf **)vfs_set.ls_items;
	vfsconf = *vfc;		/* simulate Lite2 vfsconf array */
	while (*vfc) {
		struct vfsconf *vfsp = *vfc;

		vfc++;
		vfsp->vfc_next = *vfc;
		if (maxtypenum <= vfsp->vfc_typenum)
			maxtypenum = vfsp->vfc_typenum + 1;
		(*vfsp->vfc_vfsops->vfs_init)(vfsp);
	}
	/* next vfc_typenum to be used */
	maxvfsconf = maxtypenum;
}

OpenPOWER on IntegriCloud