Annotation of src/sys/miscfs/nullfs/null_vfsops.c, Revision 1.26
1.26 ! jdolecek 1: /* $NetBSD: null_vfsops.c,v 1.25 2000/03/13 23:52:41 soren Exp $ */
1.2 cgd 2:
1.1 mycroft 3: /*
1.24 wrstuden 4: * Copyright (c) 1999 National Aeronautics & Space Administration
5: * All rights reserved.
6: *
7: * This software was written by William Studenmund of the
8: * Numerical Aerospace Similation Facility, NASA Ames Research Center.
9: *
10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
1.25 soren 18: * 3. Neither the name of the National Aeronautics & Space Administration
1.24 wrstuden 19: * nor the names of its contributors may be used to endorse or promote
20: * products derived from this software without specific prior written
21: * permission.
22: *
23: * THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION
24: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB-
27: * UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
28: * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33: * POSSIBILITY OF SUCH DAMAGE.
34: */
35: /*
1.19 fvdl 36: * Copyright (c) 1992, 1993, 1995
1.1 mycroft 37: * The Regents of the University of California. All rights reserved.
38: *
39: * This code is derived from software donated to Berkeley by
40: * Jan-Simon Pendry.
41: *
42: * Redistribution and use in source and binary forms, with or without
43: * modification, are permitted provided that the following conditions
44: * are met:
45: * 1. Redistributions of source code must retain the above copyright
46: * notice, this list of conditions and the following disclaimer.
47: * 2. Redistributions in binary form must reproduce the above copyright
48: * notice, this list of conditions and the following disclaimer in the
49: * documentation and/or other materials provided with the distribution.
50: * 3. All advertising materials mentioning features or use of this software
51: * must display the following acknowledgement:
52: * This product includes software developed by the University of
53: * California, Berkeley and its contributors.
54: * 4. Neither the name of the University nor the names of its contributors
55: * may be used to endorse or promote products derived from this software
56: * without specific prior written permission.
57: *
58: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68: * SUCH DAMAGE.
69: *
70: * from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp
71: * from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
1.19 fvdl 72: * @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95
1.1 mycroft 73: */
74:
75: /*
76: * Null Layer
77: * (See null_vnops.c for a description of what this does.)
78: */
79:
80: #include <sys/param.h>
81: #include <sys/systm.h>
82: #include <sys/time.h>
1.19 fvdl 83: #include <sys/proc.h>
1.1 mycroft 84: #include <sys/types.h>
85: #include <sys/vnode.h>
86: #include <sys/mount.h>
87: #include <sys/namei.h>
88: #include <sys/malloc.h>
89: #include <miscfs/nullfs/null.h>
1.24 wrstuden 90: #include <miscfs/genfs/layer_extern.h>
1.1 mycroft 91:
1.14 cgd 92: int nullfs_mount __P((struct mount *, const char *, void *,
1.10 christos 93: struct nameidata *, struct proc *));
94: int nullfs_unmount __P((struct mount *, int, struct proc *));
1.24 wrstuden 95:
96: #define NNULLNODECACHE 16
97:
1.1 mycroft 98: /*
99: * Mount null layer
100: */
101: int
102: nullfs_mount(mp, path, data, ndp, p)
103: struct mount *mp;
1.14 cgd 104: const char *path;
105: void *data;
1.1 mycroft 106: struct nameidata *ndp;
107: struct proc *p;
108: {
109: int error = 0;
110: struct null_args args;
111: struct vnode *lowerrootvp, *vp;
1.24 wrstuden 112: struct null_mount *nmp;
113: struct layer_mount *lmp;
1.8 mycroft 114: size_t size;
1.1 mycroft 115:
116: #ifdef NULLFS_DIAGNOSTIC
1.16 christos 117: printf("nullfs_mount(mp = %p)\n", mp);
1.1 mycroft 118: #endif
119:
120: /*
121: * Get argument
122: */
1.10 christos 123: error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
124: if (error)
1.1 mycroft 125: return (error);
126:
127: /*
1.24 wrstuden 128: * Update only does export updating.
129: */
130: if (mp->mnt_flag & MNT_UPDATE) {
131: lmp = MOUNTTOLAYERMOUNT(mp);
132: if (args.nulla_target == 0)
133: return (vfs_export(mp, &lmp->layerm_export,
134: &args.la.export));
135: else
136: return (EOPNOTSUPP);
137: }
138:
139: /*
1.1 mycroft 140: * Find lower node
141: */
142: NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
1.24 wrstuden 143: UIO_USERSPACE, args.la.target, p);
1.10 christos 144: if ((error = namei(ndp)) != 0)
1.1 mycroft 145: return (error);
146:
147: /*
148: * Sanity check on lower vnode
149: */
150: lowerrootvp = ndp->ni_vp;
151:
152: vrele(ndp->ni_dvp);
153: ndp->ni_dvp = NULL;
154:
1.24 wrstuden 155: /*
156: * First cut at fixing up upper mount point
157: */
158: nmp = (struct null_mount *) malloc(sizeof(struct null_mount),
1.1 mycroft 159: M_UFSMNT, M_WAITOK); /* XXX */
1.24 wrstuden 160: memset((caddr_t)nmp, 0, sizeof(struct null_mount));
161:
162: mp->mnt_data = (qaddr_t) nmp;
163: nmp->nullm_vfs = lowerrootvp->v_mount;
164: if (nmp->nullm_vfs->mnt_flag & MNT_LOCAL)
165: mp->mnt_flag |= MNT_LOCAL;
1.1 mycroft 166:
167: /*
1.24 wrstuden 168: * Make sure that the mount point is sufficiently initialized
169: * that the node create call will work.
1.1 mycroft 170: */
1.24 wrstuden 171: vfs_getnewfsid(mp, MOUNT_NULL);
172:
173: nmp->nullm_size = sizeof (struct null_node);
174: nmp->nullm_tag = VT_NULL;
175: nmp->nullm_bypass = layer_bypass;
176: nmp->nullm_alloc = layer_node_alloc; /* the default alloc is fine */
177: nmp->nullm_vnodeop_p = null_vnodeop_p;
178: simple_lock_init(&nmp->nullm_hashlock);
179: nmp->nullm_node_hashtbl = hashinit(NNULLNODECACHE, M_CACHE, M_WAITOK,
180: &nmp->nullm_node_hash);
1.1 mycroft 181:
182: /*
1.24 wrstuden 183: * Fix up null node for root vnode
1.1 mycroft 184: */
1.24 wrstuden 185: error = layer_node_create(mp, lowerrootvp, &vp);
1.1 mycroft 186: /*
1.24 wrstuden 187: * Make sure the fixup worked
1.1 mycroft 188: */
189: if (error) {
1.24 wrstuden 190: vput(lowerrootvp);
191: free(nmp, M_UFSMNT); /* XXX */
1.1 mycroft 192: return (error);
193: }
1.21 wrstuden 194: /*
1.24 wrstuden 195: * Unlock the node
1.21 wrstuden 196: */
197: VOP_UNLOCK(vp, 0);
1.1 mycroft 198:
199: /*
200: * Keep a held reference to the root vnode.
201: * It is vrele'd in nullfs_unmount.
202: */
1.24 wrstuden 203: vp->v_flag |= VROOT;
204: nmp->nullm_rootvp = vp;
1.1 mycroft 205:
206: (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
1.20 perry 207: memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
1.24 wrstuden 208: (void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
1.1 mycroft 209: &size);
1.20 perry 210: memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
1.1 mycroft 211: #ifdef NULLFS_DIAGNOSTIC
1.13 christos 212: printf("nullfs_mount: lower %s, alias at %s\n",
1.12 christos 213: mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
1.1 mycroft 214: #endif
215: return (0);
216: }
217:
218: /*
219: * Free reference to null layer
220: */
221: int
222: nullfs_unmount(mp, mntflags, p)
223: struct mount *mp;
224: int mntflags;
225: struct proc *p;
226: {
1.24 wrstuden 227: struct vnode *null_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
1.1 mycroft 228: int error;
229: int flags = 0;
230:
231: #ifdef NULLFS_DIAGNOSTIC
1.16 christos 232: printf("nullfs_unmount(mp = %p)\n", mp);
1.1 mycroft 233: #endif
234:
1.19 fvdl 235: if (mntflags & MNT_FORCE)
1.1 mycroft 236: flags |= FORCECLOSE;
237:
238: /*
239: * Clear out buffer cache. I don't think we
240: * ever get anything cached at this level at the
241: * moment, but who knows...
242: */
243: #if 0
244: mntflushbuf(mp, 0);
245: if (mntinvalbuf(mp, 1))
246: return (EBUSY);
247: #endif
1.24 wrstuden 248: if (null_rootvp->v_usecount > 1)
1.1 mycroft 249: return (EBUSY);
1.24 wrstuden 250: if ((error = vflush(mp, null_rootvp, flags)) != 0)
1.1 mycroft 251: return (error);
252:
253: #ifdef NULLFS_DIAGNOSTIC
1.24 wrstuden 254: vprint("alias root of lower", null_rootvp);
1.1 mycroft 255: #endif
256: /*
257: * Release reference on underlying root vnode
258: */
1.24 wrstuden 259: vrele(null_rootvp);
1.1 mycroft 260: /*
261: * And blow it away for future re-use
262: */
1.24 wrstuden 263: vgone(null_rootvp);
1.1 mycroft 264: /*
265: * Finally, throw away the null_mount structure
266: */
267: free(mp->mnt_data, M_UFSMNT); /* XXX */
268: mp->mnt_data = 0;
269: return 0;
270: }
271:
1.19 fvdl 272: extern struct vnodeopv_desc null_vnodeop_opv_desc;
1.18 thorpej 273:
274: struct vnodeopv_desc *nullfs_vnodeopv_descs[] = {
1.19 fvdl 275: &null_vnodeop_opv_desc,
1.18 thorpej 276: NULL,
277: };
278:
1.17 thorpej 279: struct vfsops nullfs_vfsops = {
1.1 mycroft 280: MOUNT_NULL,
281: nullfs_mount,
1.24 wrstuden 282: layerfs_start,
1.1 mycroft 283: nullfs_unmount,
1.24 wrstuden 284: layerfs_root,
285: layerfs_quotactl,
286: layerfs_statfs,
287: layerfs_sync,
288: layerfs_vget,
289: layerfs_fhtovp,
290: layerfs_vptofh,
291: layerfs_init,
1.26 ! jdolecek 292: layerfs_done,
1.24 wrstuden 293: layerfs_sysctl,
1.18 thorpej 294: NULL, /* vfs_mountroot */
1.24 wrstuden 295: layerfs_checkexp,
1.18 thorpej 296: nullfs_vnodeopv_descs,
1.1 mycroft 297: };
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