Drop GCC < 1 support, simplify inline assembly and use proper #error for
[dragonfly.git] / sys / vfs / nullfs / null_vfsops.c
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1/*
2 * Copyright (c) 1992, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software donated to Berkeley by
6 * Jan-Simon Pendry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94
37 *
38 * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
39 * $FreeBSD: src/sys/miscfs/nullfs/null_vfsops.c,v 1.35.2.3 2001/07/26 20:37:11 iedowse Exp $
75ffff0d 40 * $DragonFly: src/sys/vfs/nullfs/null_vfsops.c,v 1.16 2005/02/02 21:34:18 joerg Exp $
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41 */
42
43/*
44 * Null Layer
45 * (See null_vnops.c for a description of what this does.)
46 */
47
48#include <sys/param.h>
49#include <sys/systm.h>
50#include <sys/kernel.h>
51#include <sys/proc.h>
52#include <sys/malloc.h>
53#include <sys/vnode.h>
54#include <sys/mount.h>
fad57d0e 55#include <sys/nlookup.h>
1f2de5d4 56#include "null.h"
984263bc 57
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58extern struct vnodeopv_entry_desc null_vnodeop_entries[];
59
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60static MALLOC_DEFINE(M_NULLFSMNT, "NULLFS mount", "NULLFS mount structure");
61
62static int nullfs_fhtovp(struct mount *mp, struct fid *fidp,
63 struct vnode **vpp);
64static int nullfs_checkexp(struct mount *mp, struct sockaddr *nam,
65 int *extflagsp, struct ucred **credanonp);
66static int nullfs_mount(struct mount *mp, char *path, caddr_t data,
21739618 67 struct thread *td);
984263bc 68static int nullfs_quotactl(struct mount *mp, int cmd, uid_t uid,
dadab5e9 69 caddr_t arg, struct thread *td);
984263bc 70static int nullfs_root(struct mount *mp, struct vnode **vpp);
dadab5e9 71static int nullfs_start(struct mount *mp, int flags, struct thread *td);
984263bc 72static int nullfs_statfs(struct mount *mp, struct statfs *sbp,
dadab5e9 73 struct thread *td);
3b568787 74static int nullfs_sync(struct mount *mp, int waitfor, struct thread *td);
dadab5e9 75static int nullfs_unmount(struct mount *mp, int mntflags, struct thread *td);
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76static int nullfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp);
77static int nullfs_vptofh(struct vnode *vp, struct fid *fhp);
78static int nullfs_extattrctl(struct mount *mp, int cmd,
dadab5e9 79 const char *attrname, caddr_t arg, struct thread *td);
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80
81/*
82 * Mount null layer
83 */
84static int
21739618 85nullfs_mount(struct mount *mp, char *path, caddr_t data, struct thread *td)
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86{
87 int error = 0;
88 struct null_args args;
89 struct vnode *lowerrootvp, *vp;
90 struct vnode *nullm_rootvp;
91 struct null_mount *xmp;
92 u_int size;
93 int isvnunlocked = 0;
fad57d0e 94 struct nlookupdata nd;
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95
96 NULLFSDEBUG("nullfs_mount(mp = %p)\n", (void *)mp);
97
98 /*
99 * Update is a no-op
100 */
101 if (mp->mnt_flag & MNT_UPDATE) {
102 return (EOPNOTSUPP);
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103 }
104
105 /*
106 * Get argument
107 */
108 error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
109 if (error)
110 return (error);
111
112 /*
113 * Unlock lower node to avoid deadlock.
114 * (XXX) VOP_ISLOCKED is needed?
115 */
0961aa92 116 if ((mp->mnt_vnodecovered->v_tag == VT_NULL) &&
984263bc 117 VOP_ISLOCKED(mp->mnt_vnodecovered, NULL)) {
5fd012e0 118 VOP_UNLOCK(mp->mnt_vnodecovered, 0, td);
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119 isvnunlocked = 1;
120 }
121 /*
122 * Find lower node
123 */
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124 lowerrootvp = NULL;
125 error = nlookup_init(&nd, args.target, UIO_USERSPACE, NLC_FOLLOW);
126 if (error == 0)
127 error = nlookup(&nd);
128 if (error == 0) {
129 error = cache_vget(nd.nl_ncp, nd.nl_cred, LK_EXCLUSIVE,
130 &lowerrootvp);
131 }
132 nlookup_done(&nd);
133
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134 /*
135 * Re-lock vnode.
136 */
137 if (isvnunlocked && !VOP_ISLOCKED(mp->mnt_vnodecovered, NULL))
5fd012e0 138 vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY, td);
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139 if (error)
140 return (error);
fad57d0e 141
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142 /*
143 * Sanity check on lower vnode
fad57d0e 144 *
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145 * Check multi null mount to avoid `lock against myself' panic.
146 */
147 if (lowerrootvp == VTONULL(mp->mnt_vnodecovered)->null_lowervp) {
148 NULLFSDEBUG("nullfs_mount: multi null mount?\n");
149 vput(lowerrootvp);
150 return (EDEADLK);
151 }
152
153 xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
154 M_NULLFSMNT, M_WAITOK); /* XXX */
155
156 /*
157 * Save reference to underlying FS
158 */
159 xmp->nullm_vfs = lowerrootvp->v_mount;
160
6ddb7618 161 vfs_add_vnodeops(mp, &mp->mnt_vn_norm_ops, null_vnodeop_entries);
0961aa92 162
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163 /*
164 * Save reference. Each mount also holds
165 * a reference on the root vnode.
166 */
167 error = null_node_create(mp, lowerrootvp, &vp);
168 /*
169 * Unlock the node (either the lower or the alias)
170 */
5fd012e0 171 VOP_UNLOCK(vp, 0, td);
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172 /*
173 * Make sure the node alias worked
174 */
175 if (error) {
176 vrele(lowerrootvp);
177 free(xmp, M_NULLFSMNT); /* XXX */
178 return (error);
179 }
180
181 /*
182 * Keep a held reference to the root vnode.
183 * It is vrele'd in nullfs_unmount.
184 */
185 nullm_rootvp = vp;
186 nullm_rootvp->v_flag |= VROOT;
187 xmp->nullm_rootvp = nullm_rootvp;
188 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
189 mp->mnt_flag |= MNT_LOCAL;
190 mp->mnt_data = (qaddr_t) xmp;
191 vfs_getnewfsid(mp);
192
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193 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
194 &size);
195 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
dadab5e9 196 (void)nullfs_statfs(mp, &mp->mnt_stat, td);
984263bc 197 NULLFSDEBUG("nullfs_mount: lower %s, alias at %s\n",
75ffff0d 198 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntfromname);
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199 return (0);
200}
201
202/*
203 * VFS start. Nothing needed here - the start routine
204 * on the underlying filesystem will have been called
205 * when that filesystem was mounted.
206 */
207static int
dadab5e9 208nullfs_start(struct mount *mp, int flags, struct thread *td)
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209{
210 return (0);
dadab5e9 211 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, td); */
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212}
213
214/*
215 * Free reference to null layer
216 */
217static int
dadab5e9 218nullfs_unmount(struct mount *mp, int mntflags, struct thread *td)
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219{
220 void *mntdata;
221 int error;
222 int flags = 0;
223
224 NULLFSDEBUG("nullfs_unmount: mp = %p\n", (void *)mp);
225
226 if (mntflags & MNT_FORCE)
227 flags |= FORCECLOSE;
228
229 /* There is 1 extra root vnode reference (nullm_rootvp). */
230 error = vflush(mp, 1, flags);
231 if (error)
232 return (error);
233
234 /*
235 * Finally, throw away the null_mount structure
236 */
237 mntdata = mp->mnt_data;
238 mp->mnt_data = 0;
239 free(mntdata, M_NULLFSMNT);
240 return 0;
241}
242
243static int
dadab5e9 244nullfs_root(struct mount *mp, struct vnode **vpp)
984263bc 245{
dadab5e9 246 struct thread *td = curthread; /* XXX */
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247 struct vnode *vp;
248
249 NULLFSDEBUG("nullfs_root(mp = %p, vp = %p->%p)\n", (void *)mp,
250 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp,
251 (void *)NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
252
253 /*
254 * Return locked reference to root.
255 */
256 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
597aea93 257 vref(vp);
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258
259#ifdef NULLFS_DEBUG
260 if (VOP_ISLOCKED(vp, NULL)) {
261 Debugger("root vnode is locked.\n");
262 vrele(vp);
263 return (EDEADLK);
264 }
265#endif
5fd012e0 266 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
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267 *vpp = vp;
268 return 0;
269}
270
271static int
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272nullfs_quotactl(struct mount *mp, int cmd, uid_t uid, caddr_t arg,
273 struct thread *td)
984263bc 274{
dadab5e9 275 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, td);
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276}
277
278static int
dadab5e9 279nullfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
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280{
281 int error;
282 struct statfs mstat;
283
284 NULLFSDEBUG("nullfs_statfs(mp = %p, vp = %p->%p)\n", (void *)mp,
285 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp,
286 (void *)NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
287
288 bzero(&mstat, sizeof(mstat));
289
dadab5e9 290 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, td);
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291 if (error)
292 return (error);
293
294 /* now copy across the "interesting" information and fake the rest */
295 sbp->f_type = mstat.f_type;
296 sbp->f_flags = mstat.f_flags;
297 sbp->f_bsize = mstat.f_bsize;
298 sbp->f_iosize = mstat.f_iosize;
299 sbp->f_blocks = mstat.f_blocks;
300 sbp->f_bfree = mstat.f_bfree;
301 sbp->f_bavail = mstat.f_bavail;
302 sbp->f_files = mstat.f_files;
303 sbp->f_ffree = mstat.f_ffree;
304 if (sbp != &mp->mnt_stat) {
305 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
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306 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
307 }
308 return (0);
309}
310
311static int
f4a3189a 312nullfs_sync(struct mount *mp, int waitfor, struct thread *td)
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313{
314 /*
315 * XXX - Assumes no data cached at null layer.
316 */
317 return (0);
318}
319
320static int
f4a3189a 321nullfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
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322{
323
324 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
325}
326
327static int
f4a3189a 328nullfs_fhtovp(struct mount *mp, struct fid *fidp, struct vnode **vpp)
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329{
330
331 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, vpp);
332}
333
334static int
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335nullfs_checkexp(struct mount *mp, struct sockaddr *nam, int *extflagsp,
336 struct ucred **credanonp)
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337{
338
339 return VFS_CHECKEXP(MOUNTTONULLMOUNT(mp)->nullm_vfs, nam,
340 extflagsp, credanonp);
341}
342
343static int
f4a3189a 344nullfs_vptofh(struct vnode *vp, struct fid *fhp)
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345{
346 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
347}
348
349static int
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350nullfs_extattrctl(struct mount *mp, int cmd, const char *attrname, caddr_t arg,
351 struct thread *td)
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352{
353 return VFS_EXTATTRCTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, attrname,
dadab5e9 354 arg, td);
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355}
356
357
358static struct vfsops null_vfsops = {
359 nullfs_mount,
360 nullfs_start,
361 nullfs_unmount,
362 nullfs_root,
363 nullfs_quotactl,
364 nullfs_statfs,
365 nullfs_sync,
366 nullfs_vget,
367 nullfs_fhtovp,
368 nullfs_checkexp,
369 nullfs_vptofh,
370 nullfs_init,
371 nullfs_uninit,
372 nullfs_extattrctl,
373};
374
375VFS_SET(null_vfsops, null, VFCF_LOOPBACK);