Bump .Dd, add .Lb, and use 'RFC xxxx'.
[dragonfly.git] / sys / vfs / nullfs / null_vfsops.c
CommitLineData
984263bc
MD
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 $
28623bf9 40 * $DragonFly: src/sys/vfs/nullfs/null_vfsops.c,v 1.29 2006/10/27 04:56:34 dillon Exp $
984263bc
MD
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
66a1ddf5 58extern struct vop_ops null_vnode_vops;
0961aa92 59
984263bc
MD
60static MALLOC_DEFINE(M_NULLFSMNT, "NULLFS mount", "NULLFS mount structure");
61
984263bc 62static int nullfs_root(struct mount *mp, struct vnode **vpp);
984263bc 63static int nullfs_statfs(struct mount *mp, struct statfs *sbp,
acde96db 64 struct ucred *cred);
984263bc
MD
65
66/*
67 * Mount null layer
68 */
69static int
acde96db 70nullfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
984263bc
MD
71{
72 int error = 0;
73 struct null_args args;
8cb8b61a 74 struct vnode *rootvp;
984263bc
MD
75 struct null_mount *xmp;
76 u_int size;
fad57d0e 77 struct nlookupdata nd;
984263bc
MD
78
79 NULLFSDEBUG("nullfs_mount(mp = %p)\n", (void *)mp);
80
81 /*
82 * Update is a no-op
83 */
84 if (mp->mnt_flag & MNT_UPDATE) {
85 return (EOPNOTSUPP);
984263bc
MD
86 }
87
88 /*
89 * Get argument
90 */
91 error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
92 if (error)
93 return (error);
94
984263bc
MD
95 /*
96 * Find lower node
97 */
8cb8b61a 98 rootvp = NULL;
fad57d0e 99 error = nlookup_init(&nd, args.target, UIO_USERSPACE, NLC_FOLLOW);
28623bf9
MD
100 if (error)
101 goto fail1;
102 error = nlookup(&nd);
103 if (error)
104 goto fail2;
105 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &rootvp);
106 if (error)
107 goto fail2;
984263bc 108
77652cad 109 xmp = (struct null_mount *) kmalloc(sizeof(struct null_mount),
984263bc
MD
110 M_NULLFSMNT, M_WAITOK); /* XXX */
111
112 /*
113 * Save reference to underlying FS
28623bf9 114 *
8cb8b61a 115 * As lite stacking enters the scene, the old way of doing this
28623bf9
MD
116 * -- via the vnode -- is not good enough anymore. Use the
117 * underlying filesystem's namecache handle as our mount point
118 * root, adjusting the mount to point to us.
119 *
120 * NCF_ISMOUNTPT is normally set on the mount point, but we also
121 * want to set it on the base directory being mounted to prevent
122 * that directory from being destroyed out from under the nullfs
123 * mount.
8cb8b61a 124 */
28623bf9
MD
125 xmp->nullm_vfs = nd.nl_nch.mount;
126 mp->mnt_ncmountpt = nd.nl_nch;
127 cache_changemount(&mp->mnt_ncmountpt, mp);
128 mp->mnt_ncmountpt.ncp->nc_flag |= NCF_ISMOUNTPT;
129 cache_unlock(&mp->mnt_ncmountpt);
130 cache_zero(&nd.nl_nch);
8cb8b61a 131 nlookup_done(&nd);
984263bc 132
66a1ddf5 133 vfs_add_vnodeops(mp, &null_vnode_vops, &mp->mnt_vn_norm_ops);
0961aa92 134
28623bf9 135 vn_unlock(rootvp); /* leave reference intact */
984263bc
MD
136
137 /*
138 * Keep a held reference to the root vnode.
139 * It is vrele'd in nullfs_unmount.
140 */
8cb8b61a
MD
141 xmp->nullm_rootvp = rootvp;
142 /*
143 * XXX What's the proper safety condition for querying
144 * the underlying mount? Is this flag tuning necessary
145 * at all?
146 */
147 if (xmp->nullm_vfs->mnt_flag & MNT_LOCAL)
984263bc
MD
148 mp->mnt_flag |= MNT_LOCAL;
149 mp->mnt_data = (qaddr_t) xmp;
150 vfs_getnewfsid(mp);
151
984263bc
MD
152 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
153 &size);
154 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
acde96db 155 (void)nullfs_statfs(mp, &mp->mnt_stat, cred);
984263bc 156 NULLFSDEBUG("nullfs_mount: lower %s, alias at %s\n",
75ffff0d 157 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntfromname);
28623bf9
MD
158
159 /*
160 * So unmount won't complain about namecache refs still existing
161 */
162 mp->mnt_kern_flag |= MNTK_NCALIASED;
984263bc 163 return (0);
28623bf9
MD
164fail2:
165 nlookup_done(&nd);
166fail1:
167 return (error);
984263bc
MD
168}
169
984263bc
MD
170/*
171 * Free reference to null layer
172 */
173static int
acde96db 174nullfs_unmount(struct mount *mp, int mntflags)
984263bc 175{
b81dacf0 176 struct null_mount *xmp;
984263bc
MD
177 int flags = 0;
178
179 NULLFSDEBUG("nullfs_unmount: mp = %p\n", (void *)mp);
180
181 if (mntflags & MNT_FORCE)
182 flags |= FORCECLOSE;
183
984263bc
MD
184 /*
185 * Finally, throw away the null_mount structure
186 */
8e77d370 187 xmp = (void *)mp->mnt_data;
984263bc 188 mp->mnt_data = 0;
b81dacf0
MD
189 if (xmp->nullm_rootvp) {
190 vrele(xmp->nullm_rootvp);
191 xmp->nullm_rootvp = NULL;
192 }
193 kfree(xmp, M_NULLFSMNT);
984263bc
MD
194 return 0;
195}
196
197static int
dadab5e9 198nullfs_root(struct mount *mp, struct vnode **vpp)
984263bc 199{
984263bc 200 struct vnode *vp;
44b1cf3d 201 int error;
984263bc 202
8cb8b61a
MD
203 NULLFSDEBUG("nullfs_root(mp = %p, vp = %p)\n", (void *)mp,
204 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp);
984263bc
MD
205
206 /*
207 * Return locked reference to root.
208 */
209 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
44b1cf3d
MD
210 error = vget(vp, LK_EXCLUSIVE | LK_RETRY);
211 if (error == 0)
212 *vpp = vp;
213 return (error);
984263bc
MD
214}
215
216static int
f4a3189a 217nullfs_quotactl(struct mount *mp, int cmd, uid_t uid, caddr_t arg,
acde96db 218 struct ucred *cred)
984263bc 219{
acde96db 220 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, cred);
984263bc
MD
221}
222
223static int
acde96db 224nullfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
984263bc
MD
225{
226 int error;
227 struct statfs mstat;
228
8cb8b61a
MD
229 NULLFSDEBUG("nullfs_statfs(mp = %p, vp = %p)\n", (void *)mp,
230 (void *)MOUNTTONULLMOUNT(mp)->nullm_rootvp);
984263bc
MD
231
232 bzero(&mstat, sizeof(mstat));
233
acde96db 234 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, cred);
984263bc
MD
235 if (error)
236 return (error);
237
238 /* now copy across the "interesting" information and fake the rest */
239 sbp->f_type = mstat.f_type;
240 sbp->f_flags = mstat.f_flags;
241 sbp->f_bsize = mstat.f_bsize;
242 sbp->f_iosize = mstat.f_iosize;
243 sbp->f_blocks = mstat.f_blocks;
244 sbp->f_bfree = mstat.f_bfree;
245 sbp->f_bavail = mstat.f_bavail;
246 sbp->f_files = mstat.f_files;
247 sbp->f_ffree = mstat.f_ffree;
248 if (sbp != &mp->mnt_stat) {
249 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
984263bc
MD
250 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
251 }
252 return (0);
253}
254
984263bc 255static int
f4a3189a
CP
256nullfs_checkexp(struct mount *mp, struct sockaddr *nam, int *extflagsp,
257 struct ucred **credanonp)
984263bc
MD
258{
259
260 return VFS_CHECKEXP(MOUNTTONULLMOUNT(mp)->nullm_vfs, nam,
261 extflagsp, credanonp);
262}
263
984263bc 264static int
f4a3189a 265nullfs_extattrctl(struct mount *mp, int cmd, const char *attrname, caddr_t arg,
acde96db 266 struct ucred *cred)
984263bc
MD
267{
268 return VFS_EXTATTRCTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, attrname,
acde96db 269 arg, cred);
984263bc
MD
270}
271
272
273static struct vfsops null_vfsops = {
43c45e8f
HP
274 .vfs_mount = nullfs_mount,
275 .vfs_unmount = nullfs_unmount,
276 .vfs_root = nullfs_root,
277 .vfs_quotactl = nullfs_quotactl,
278 .vfs_statfs = nullfs_statfs,
279 .vfs_sync = vfs_stdsync,
43c45e8f 280 .vfs_checkexp = nullfs_checkexp,
43c45e8f 281 .vfs_extattrctl = nullfs_extattrctl
984263bc
MD
282};
283
284VFS_SET(null_vfsops, null, VFCF_LOOPBACK);