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36 * @(#)null_vfsops.c 8.2 (Berkeley) 1/21/94
38 * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
39 * $Id: null_vfsops.c,v 1.18 1997/08/02 14:32:05 bde Exp $
44 * (See null_vnops.c for a description of what this does.)
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/kernel.h>
51 #include <sys/vnode.h>
52 #include <sys/mount.h>
53 #include <sys/namei.h>
54 #include <sys/malloc.h>
55 #include <miscfs/nullfs/null.h>
57 static int nullfs_fhtovp __P((struct mount *mp, struct fid *fidp,
58 struct sockaddr *nam, struct vnode **vpp,
59 int *exflagsp, struct ucred **credanonp));
60 static int nullfs_mount __P((struct mount *mp, char *path, caddr_t data,
61 struct nameidata *ndp, struct proc *p));
62 static int nullfs_quotactl __P((struct mount *mp, int cmd, uid_t uid,
63 caddr_t arg, struct proc *p));
64 static int nullfs_root __P((struct mount *mp, struct vnode **vpp));
65 static int nullfs_start __P((struct mount *mp, int flags, struct proc *p));
66 static int nullfs_statfs __P((struct mount *mp, struct statfs *sbp,
68 static int nullfs_sync __P((struct mount *mp, int waitfor,
69 struct ucred *cred, struct proc *p));
70 static int nullfs_unmount __P((struct mount *mp, int mntflags,
72 static int nullfs_vget __P((struct mount *mp, ino_t ino,
74 static int nullfs_vptofh __P((struct vnode *vp, struct fid *fhp));
80 nullfs_mount(mp, path, data, ndp, p)
84 struct nameidata *ndp;
88 struct null_args args;
89 struct vnode *lowerrootvp, *vp;
90 struct vnode *nullm_rootvp;
91 struct null_mount *xmp;
95 #ifdef NULLFS_DIAGNOSTIC
96 printf("nullfs_mount(mp = %x)\n", mp);
102 if (mp->mnt_flag & MNT_UPDATE) {
104 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
110 error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
115 * Unlock lower node to avoid deadlock.
116 * (XXX) VOP_ISLOCKED is needed?
118 if ((mp->mnt_vnodecovered->v_op == null_vnodeop_p) &&
119 VOP_ISLOCKED(mp->mnt_vnodecovered)) {
120 VOP_UNLOCK(mp->mnt_vnodecovered, 0, p);
126 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
127 UIO_USERSPACE, args.target, p);
132 if (isvnunlocked && !VOP_ISLOCKED(mp->mnt_vnodecovered))
133 vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY, p);
139 * Sanity check on lower vnode
141 lowerrootvp = ndp->ni_vp;
144 ndp->ni_dvp = NULLVP;
147 * Check multi null mount to avoid `lock against myself' panic.
149 if (lowerrootvp == VTONULL(mp->mnt_vnodecovered)->null_lowervp) {
151 printf("nullfs_mount: multi null mount?\n");
156 xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
157 M_UFSMNT, M_WAITOK); /* XXX */
160 * Save reference to underlying FS
162 xmp->nullm_vfs = lowerrootvp->v_mount;
165 * Save reference. Each mount also holds
166 * a reference on the root vnode.
168 error = null_node_create(mp, lowerrootvp, &vp);
170 * Unlock the node (either the lower or the alias)
172 VOP_UNLOCK(vp, 0, p);
174 * Make sure the node alias worked
178 free(xmp, M_UFSMNT); /* XXX */
183 * Keep a held reference to the root vnode.
184 * It is vrele'd in nullfs_unmount.
187 nullm_rootvp->v_flag |= VROOT;
188 xmp->nullm_rootvp = nullm_rootvp;
189 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
190 mp->mnt_flag |= MNT_LOCAL;
191 mp->mnt_data = (qaddr_t) xmp;
194 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
195 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
196 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
198 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
199 #ifdef NULLFS_DIAGNOSTIC
200 printf("nullfs_mount: lower %s, alias at %s\n",
201 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
207 * VFS start. Nothing needed here - the start routine
208 * on the underlying filesystem will have been called
209 * when that filesystem was mounted.
212 nullfs_start(mp, flags, p)
218 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
222 * Free reference to null layer
225 nullfs_unmount(mp, mntflags, p)
230 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
234 #ifdef NULLFS_DIAGNOSTIC
235 printf("nullfs_unmount(mp = %x)\n", mp);
238 if (mntflags & MNT_FORCE)
242 * Clear out buffer cache. I don't think we
243 * ever get anything cached at this level at the
244 * moment, but who knows...
248 if (mntinvalbuf(mp, 1))
251 if (nullm_rootvp->v_usecount > 1)
253 error = vflush(mp, nullm_rootvp, flags);
257 #ifdef NULLFS_DIAGNOSTIC
258 vprint("alias root of lower", nullm_rootvp);
261 * Release reference on underlying root vnode
265 * And blow it away for future re-use
269 * Finally, throw away the null_mount structure
271 free(mp->mnt_data, M_UFSMNT); /* XXX */
281 struct proc *p = curproc; /* XXX */
284 #ifdef NULLFS_DIAGNOSTIC
285 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
286 MOUNTTONULLMOUNT(mp)->nullm_rootvp,
287 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
292 * Return locked reference to root.
294 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
296 if (VOP_ISLOCKED(vp)) {
299 * Should we check type of node?
302 printf("nullfs_root: multi null mount?\n");
307 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
313 nullfs_quotactl(mp, cmd, uid, arg, p)
320 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
324 nullfs_statfs(mp, sbp, p)
332 #ifdef NULLFS_DIAGNOSTIC
333 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
334 MOUNTTONULLMOUNT(mp)->nullm_rootvp,
335 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
339 bzero(&mstat, sizeof(mstat));
341 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
345 /* now copy across the "interesting" information and fake the rest */
346 sbp->f_type = mstat.f_type;
347 sbp->f_flags = mstat.f_flags;
348 sbp->f_bsize = mstat.f_bsize;
349 sbp->f_iosize = mstat.f_iosize;
350 sbp->f_blocks = mstat.f_blocks;
351 sbp->f_bfree = mstat.f_bfree;
352 sbp->f_bavail = mstat.f_bavail;
353 sbp->f_files = mstat.f_files;
354 sbp->f_ffree = mstat.f_ffree;
355 if (sbp != &mp->mnt_stat) {
356 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
357 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
358 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
364 nullfs_sync(mp, waitfor, cred, p)
371 * XXX - Assumes no data cached at null layer.
377 nullfs_vget(mp, ino, vpp)
383 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
387 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
390 struct sockaddr *nam;
393 struct ucred**credanonp;
396 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam,
397 vpp, exflagsp, credanonp);
401 nullfs_vptofh(vp, fhp)
405 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
408 static struct vfsops null_vfsops = {
422 VFS_SET(null_vfsops, null, MOUNT_NULL, VFCF_LOOPBACK);