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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 1.24 1998/02/06 12:13:40 eivind Exp $
44 * (See null_vnops.c for a description of what this does.)
47 #include "opt_debug_nullfs.h"
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/vnode.h>
55 #include <sys/mount.h>
56 #include <sys/namei.h>
57 #include <miscfs/nullfs/null.h>
59 static MALLOC_DEFINE(M_NULLFSMNT, "NULLFS mount", "NULLFS mount structure");
61 static int nullfs_fhtovp __P((struct mount *mp, struct fid *fidp,
62 struct sockaddr *nam, struct vnode **vpp,
63 int *exflagsp, struct ucred **credanonp));
64 static int nullfs_mount __P((struct mount *mp, char *path, caddr_t data,
65 struct nameidata *ndp, struct proc *p));
66 static int nullfs_quotactl __P((struct mount *mp, int cmd, uid_t uid,
67 caddr_t arg, struct proc *p));
68 static int nullfs_root __P((struct mount *mp, struct vnode **vpp));
69 static int nullfs_start __P((struct mount *mp, int flags, struct proc *p));
70 static int nullfs_statfs __P((struct mount *mp, struct statfs *sbp,
72 static int nullfs_sync __P((struct mount *mp, int waitfor,
73 struct ucred *cred, struct proc *p));
74 static int nullfs_unmount __P((struct mount *mp, int mntflags,
76 static int nullfs_vget __P((struct mount *mp, ino_t ino,
78 static int nullfs_vrele __P((struct mount *mp, struct vnode *vp));
79 static int nullfs_vptofh __P((struct vnode *vp, struct fid *fhp));
85 nullfs_mount(mp, path, data, ndp, p)
89 struct nameidata *ndp;
93 struct null_args args;
94 struct vnode *lowerrootvp, *vp;
95 struct vnode *nullm_rootvp;
96 struct null_mount *xmp;
100 #ifdef NULLFS_DIAGNOSTIC
101 printf("nullfs_mount(mp = %x)\n", mp);
107 if (mp->mnt_flag & MNT_UPDATE) {
109 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
115 error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
120 * Unlock lower node to avoid deadlock.
121 * (XXX) VOP_ISLOCKED is needed?
123 if ((mp->mnt_vnodecovered->v_op == null_vnodeop_p) &&
124 VOP_ISLOCKED(mp->mnt_vnodecovered)) {
125 VOP_UNLOCK(mp->mnt_vnodecovered, 0, p);
131 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
132 UIO_USERSPACE, args.target, p);
137 if (isvnunlocked && !VOP_ISLOCKED(mp->mnt_vnodecovered))
138 vn_lock(mp->mnt_vnodecovered, LK_EXCLUSIVE | LK_RETRY, p);
144 * Sanity check on lower vnode
146 lowerrootvp = ndp->ni_vp;
149 ndp->ni_dvp = NULLVP;
152 * Check multi null mount to avoid `lock against myself' panic.
154 if (lowerrootvp == VTONULL(mp->mnt_vnodecovered)->null_lowervp) {
156 printf("nullfs_mount: multi null mount?\n");
161 xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
162 M_NULLFSMNT, M_WAITOK); /* XXX */
165 * Save reference to underlying FS
167 xmp->nullm_vfs = lowerrootvp->v_mount;
170 * Save reference. Each mount also holds
171 * a reference on the root vnode.
173 error = null_node_create(mp, lowerrootvp, &vp);
175 * Unlock the node (either the lower or the alias)
177 VOP_UNLOCK(vp, 0, p);
179 * Make sure the node alias worked
183 free(xmp, M_NULLFSMNT); /* XXX */
188 * Keep a held reference to the root vnode.
189 * It is vrele'd in nullfs_unmount.
192 nullm_rootvp->v_flag |= VROOT;
193 xmp->nullm_rootvp = nullm_rootvp;
194 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
195 mp->mnt_flag |= MNT_LOCAL;
196 mp->mnt_data = (qaddr_t) xmp;
199 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
200 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
201 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
203 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
204 (void)nullfs_statfs(mp, &mp->mnt_stat, p);
205 #ifdef NULLFS_DIAGNOSTIC
206 printf("nullfs_mount: lower %s, alias at %s\n",
207 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
213 * VFS start. Nothing needed here - the start routine
214 * on the underlying filesystem will have been called
215 * when that filesystem was mounted.
218 nullfs_start(mp, flags, p)
224 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
228 * Free reference to null layer
231 nullfs_unmount(mp, mntflags, p)
236 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
240 #ifdef NULLFS_DIAGNOSTIC
241 printf("nullfs_unmount(mp = %x)\n", mp);
244 if (mntflags & MNT_FORCE)
248 * Clear out buffer cache. I don't think we
249 * ever get anything cached at this level at the
250 * moment, but who knows...
254 if (mntinvalbuf(mp, 1))
257 if (nullm_rootvp->v_usecount > 1)
259 error = vflush(mp, nullm_rootvp, flags);
263 #ifdef NULLFS_DIAGNOSTIC
264 vprint("alias root of lower", nullm_rootvp);
267 * Release reference on underlying root vnode
271 * And blow it away for future re-use
275 * Finally, throw away the null_mount structure
277 free(mp->mnt_data, M_NULLFSMNT); /* XXX */
287 struct proc *p = curproc; /* XXX */
290 #ifdef NULLFS_DIAGNOSTIC
291 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
292 MOUNTTONULLMOUNT(mp)->nullm_rootvp,
293 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
298 * Return locked reference to root.
300 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
302 if (VOP_ISLOCKED(vp)) {
305 * Should we check type of node?
308 printf("nullfs_root: multi null mount?\n");
313 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
319 nullfs_quotactl(mp, cmd, uid, arg, p)
326 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
330 nullfs_statfs(mp, sbp, p)
338 #ifdef NULLFS_DIAGNOSTIC
339 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
340 MOUNTTONULLMOUNT(mp)->nullm_rootvp,
341 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
345 bzero(&mstat, sizeof(mstat));
347 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
351 /* now copy across the "interesting" information and fake the rest */
352 sbp->f_type = mstat.f_type;
353 sbp->f_flags = mstat.f_flags;
354 sbp->f_bsize = mstat.f_bsize;
355 sbp->f_iosize = mstat.f_iosize;
356 sbp->f_blocks = mstat.f_blocks;
357 sbp->f_bfree = mstat.f_bfree;
358 sbp->f_bavail = mstat.f_bavail;
359 sbp->f_files = mstat.f_files;
360 sbp->f_ffree = mstat.f_ffree;
361 if (sbp != &mp->mnt_stat) {
362 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
363 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
364 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
370 nullfs_sync(mp, waitfor, cred, p)
377 * XXX - Assumes no data cached at null layer.
383 nullfs_vget(mp, ino, vpp)
389 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
393 * Complement to all vpp returning ops.
394 * XXX - initially only to get rid of WILLRELE.
404 error = VFS_VRELE(MOUNTTONULLMOUNT(mp)->nullm_vfs,
405 NULLVPTOLOWERVP(vp));
411 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
414 struct sockaddr *nam;
417 struct ucred**credanonp;
420 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam,
421 vpp, exflagsp, credanonp);
425 nullfs_vptofh(vp, fhp)
429 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
432 static struct vfsops null_vfsops = {
447 VFS_SET(null_vfsops, null, MOUNT_NULL, VFCF_LOOPBACK);