Annotation of src/sys/miscfs/overlay/overlay_vfsops.c, Revision 1.7
1.7 ! wiz 1: /* $NetBSD: overlay_vfsops.c,v 1.6 2001/01/22 12:17:39 jdolecek Exp $ */
1.1 wrstuden 2:
3: /*
4: * Copyright (c) 1999, 2000 National Aeronautics & Space Administration
5: * All rights reserved.
6: *
7: * This software was written by William Studenmund of the
1.7 ! wiz 8: * Numerical Aerospace Simulation Facility, NASA Ames Research Center.
1.1 wrstuden 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.
1.2 soren 18: * 3. Neither the name of the National Aeronautics & Space Administration
1.1 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: /*
36: * Copyright (c) 1992, 1993, 1995
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
72: * @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95
73: */
74:
75: /*
1.7 ! wiz 76: * Overlay Layer
! 77: * (See overlay_vnops.c for a description of what this does.)
1.1 wrstuden 78: */
79:
80: #include <sys/param.h>
81: #include <sys/systm.h>
82: #include <sys/time.h>
83: #include <sys/proc.h>
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/overlay/overlay.h>
90: #include <miscfs/genfs/layer_extern.h>
91:
92: int ov_mount __P((struct mount *, const char *, void *,
93: struct nameidata *, struct proc *));
94: int ov_unmount __P((struct mount *, int, struct proc *));
95:
96: #define NOVERLAYNODECACHE 16
97:
98: /*
99: * Mount overlay layer
100: */
101: int
102: ov_mount(mp, path, data, ndp, p)
103: struct mount *mp;
104: const char *path;
105: void *data;
106: struct nameidata *ndp;
107: struct proc *p;
108: {
109: int error = 0;
110: struct overlay_args args;
111: struct vnode *lowerrootvp, *vp;
112: struct overlay_mount *nmp;
113: struct layer_mount *lmp;
114: size_t size;
115:
116: #ifdef OVERLAYFS_DIAGNOSTIC
117: printf("ov_mount(mp = %p)\n", mp);
118: #endif
119:
120: /*
121: * Get argument
122: */
123: error = copyin(data, (caddr_t)&args, sizeof(struct overlay_args));
124: if (error)
125: return (error);
126:
127: /*
128: * Update only does export updating.
129: */
130: if (mp->mnt_flag & MNT_UPDATE) {
131: lmp = MOUNTTOLAYERMOUNT(mp);
132: if (args.ova_target == 0)
133: return (vfs_export(mp, &lmp->layerm_export,
134: &args.la.export));
135: else
136: return (EOPNOTSUPP);
137: }
138:
139: /*
140: * Find lower node
141: */
142: lowerrootvp = mp->mnt_vnodecovered;
143: if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY)))
144: return (error);
145:
146: /*
147: * First cut at fixing up upper mount point
148: */
149: nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount),
150: M_UFSMNT, M_WAITOK); /* XXX */
151: memset((caddr_t)nmp, 0, sizeof(struct overlay_mount));
152:
153: mp->mnt_data = (qaddr_t) nmp;
154: nmp->ovm_vfs = lowerrootvp->v_mount;
155: if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL)
156: mp->mnt_flag |= MNT_LOCAL;
157:
158: /*
159: * Make sure that the mount point is sufficiently initialized
160: * that the node create call will work.
161: */
1.4 assar 162: vfs_getnewfsid(mp);
1.1 wrstuden 163:
164: nmp->ovm_size = sizeof (struct overlay_node);
165: nmp->ovm_tag = VT_OVERLAY;
166: nmp->ovm_bypass = layer_bypass;
167: nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */
168: nmp->ovm_vnodeop_p = overlay_vnodeop_p;
169: simple_lock_init(&nmp->ovm_hashlock);
1.5 ad 170: nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE,
171: M_WAITOK, &nmp->ovm_node_hash);
1.1 wrstuden 172:
173: /*
174: * Fix up overlay node for root vnode
175: */
176: error = layer_node_create(mp, lowerrootvp, &vp);
177: /*
178: * Make sure the fixup worked
179: */
180: if (error) {
181: vput(lowerrootvp);
182: free(nmp, M_UFSMNT); /* XXX */
183: return (error);
184: }
185: /*
186: * Unlock the node
187: */
188: VOP_UNLOCK(vp, 0);
189:
190: /*
191: * Keep a held reference to the root vnode.
192: * It is vrele'd in ov_unmount.
193: */
194: vp->v_flag |= VROOT;
195: nmp->ovm_rootvp = vp;
196:
197: (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
198: memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
199: (void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
200: &size);
201: memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
202: #ifdef OVERLAYFS_DIAGNOSTIC
203: printf("ov_mount: lower %s, alias at %s\n",
204: mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
205: #endif
206: return (0);
207: }
208:
209: /*
210: * Free reference to overlay layer
211: */
212: int
213: ov_unmount(mp, mntflags, p)
214: struct mount *mp;
215: int mntflags;
216: struct proc *p;
217: {
218: struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp;
219: int error;
220: int flags = 0;
221:
222: #ifdef OVERLAYFS_DIAGNOSTIC
223: printf("ov_unmount(mp = %p)\n", mp);
224: #endif
225:
226: if (mntflags & MNT_FORCE)
227: flags |= FORCECLOSE;
228:
229: /*
230: * Clear out buffer cache. I don't think we
231: * ever get anything cached at this level at the
232: * moment, but who knows...
233: */
234: #if 0
235: mntflushbuf(mp, 0);
236: if (mntinvalbuf(mp, 1))
237: return (EBUSY);
238: #endif
239: if (overlay_rootvp->v_usecount > 1)
240: return (EBUSY);
241: if ((error = vflush(mp, overlay_rootvp, flags)) != 0)
242: return (error);
243:
244: #ifdef OVERLAYFS_DIAGNOSTIC
245: vprint("alias root of lower", overlay_rootvp);
246: #endif
247: /*
248: * Release reference on underlying root vnode
249: */
250: vrele(overlay_rootvp);
251: /*
252: * And blow it away for future re-use
253: */
254: vgone(overlay_rootvp);
255: /*
256: * Finally, throw away the overlay_mount structure
257: */
258: free(mp->mnt_data, M_UFSMNT); /* XXX */
259: mp->mnt_data = 0;
260: return 0;
261: }
262:
1.6 jdolecek 263: extern const struct vnodeopv_desc overlay_vnodeop_opv_desc;
1.1 wrstuden 264:
1.6 jdolecek 265: const struct vnodeopv_desc * const ov_vnodeopv_descs[] = {
1.1 wrstuden 266: &overlay_vnodeop_opv_desc,
267: NULL,
268: };
269:
270: struct vfsops overlay_vfsops = {
271: MOUNT_OVERLAY,
272: ov_mount,
273: layerfs_start,
274: ov_unmount,
275: layerfs_root,
276: layerfs_quotactl,
277: layerfs_statfs,
278: layerfs_sync,
279: layerfs_vget,
280: layerfs_fhtovp,
281: layerfs_vptofh,
282: layerfs_init,
1.3 jdolecek 283: layerfs_done,
1.1 wrstuden 284: layerfs_sysctl,
285: NULL, /* vfs_mountroot */
286: layerfs_checkexp,
287: ov_vnodeopv_descs,
288: };
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