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overlay_vfsops.c revision 1.7.4.1
      1  1.7.4.1      fvdl /*	$NetBSD: overlay_vfsops.c,v 1.7.4.1 2001/10/01 12:47:20 fvdl Exp $	*/
      2      1.1  wrstuden 
      3      1.1  wrstuden /*
      4      1.1  wrstuden  * Copyright (c) 1999, 2000 National Aeronautics & Space Administration
      5      1.1  wrstuden  * All rights reserved.
      6      1.1  wrstuden  *
      7      1.1  wrstuden  * This software was written by William Studenmund of the
      8      1.7       wiz  * Numerical Aerospace Simulation Facility, NASA Ames Research Center.
      9      1.1  wrstuden  *
     10      1.1  wrstuden  * Redistribution and use in source and binary forms, with or without
     11      1.1  wrstuden  * modification, are permitted provided that the following conditions
     12      1.1  wrstuden  * are met:
     13      1.1  wrstuden  * 1. Redistributions of source code must retain the above copyright
     14      1.1  wrstuden  *    notice, this list of conditions and the following disclaimer.
     15      1.1  wrstuden  * 2. Redistributions in binary form must reproduce the above copyright
     16      1.1  wrstuden  *    notice, this list of conditions and the following disclaimer in the
     17      1.1  wrstuden  *    documentation and/or other materials provided with the distribution.
     18      1.2     soren  * 3. Neither the name of the National Aeronautics & Space Administration
     19      1.1  wrstuden  *    nor the names of its contributors may be used to endorse or promote
     20      1.1  wrstuden  *    products derived from this software without specific prior written
     21      1.1  wrstuden  *    permission.
     22      1.1  wrstuden  *
     23      1.1  wrstuden  * THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION
     24      1.1  wrstuden  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     25      1.1  wrstuden  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     26      1.1  wrstuden  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB-
     27      1.1  wrstuden  * UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
     28      1.1  wrstuden  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     29      1.1  wrstuden  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     30      1.1  wrstuden  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     31      1.1  wrstuden  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     32      1.1  wrstuden  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     33      1.1  wrstuden  * POSSIBILITY OF SUCH DAMAGE.
     34      1.1  wrstuden  */
     35      1.1  wrstuden /*
     36      1.1  wrstuden  * Copyright (c) 1992, 1993, 1995
     37      1.1  wrstuden  *	The Regents of the University of California.  All rights reserved.
     38      1.1  wrstuden  *
     39      1.1  wrstuden  * This code is derived from software donated to Berkeley by
     40      1.1  wrstuden  * Jan-Simon Pendry.
     41      1.1  wrstuden  *
     42      1.1  wrstuden  * Redistribution and use in source and binary forms, with or without
     43      1.1  wrstuden  * modification, are permitted provided that the following conditions
     44      1.1  wrstuden  * are met:
     45      1.1  wrstuden  * 1. Redistributions of source code must retain the above copyright
     46      1.1  wrstuden  *    notice, this list of conditions and the following disclaimer.
     47      1.1  wrstuden  * 2. Redistributions in binary form must reproduce the above copyright
     48      1.1  wrstuden  *    notice, this list of conditions and the following disclaimer in the
     49      1.1  wrstuden  *    documentation and/or other materials provided with the distribution.
     50      1.1  wrstuden  * 3. All advertising materials mentioning features or use of this software
     51      1.1  wrstuden  *    must display the following acknowledgement:
     52      1.1  wrstuden  *	This product includes software developed by the University of
     53      1.1  wrstuden  *	California, Berkeley and its contributors.
     54      1.1  wrstuden  * 4. Neither the name of the University nor the names of its contributors
     55      1.1  wrstuden  *    may be used to endorse or promote products derived from this software
     56      1.1  wrstuden  *    without specific prior written permission.
     57      1.1  wrstuden  *
     58      1.1  wrstuden  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59      1.1  wrstuden  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60      1.1  wrstuden  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61      1.1  wrstuden  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62      1.1  wrstuden  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63      1.1  wrstuden  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64      1.1  wrstuden  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65      1.1  wrstuden  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66      1.1  wrstuden  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67      1.1  wrstuden  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68      1.1  wrstuden  * SUCH DAMAGE.
     69      1.1  wrstuden  *
     70      1.1  wrstuden  *	from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp
     71      1.1  wrstuden  *	from: @(#)lofs_vfsops.c	1.2 (Berkeley) 6/18/92
     72      1.1  wrstuden  *	@(#)null_vfsops.c	8.7 (Berkeley) 5/14/95
     73      1.1  wrstuden  */
     74      1.1  wrstuden 
     75      1.1  wrstuden /*
     76      1.7       wiz  * Overlay Layer
     77      1.7       wiz  * (See overlay_vnops.c for a description of what this does.)
     78      1.1  wrstuden  */
     79      1.1  wrstuden 
     80      1.1  wrstuden #include <sys/param.h>
     81      1.1  wrstuden #include <sys/systm.h>
     82      1.1  wrstuden #include <sys/time.h>
     83      1.1  wrstuden #include <sys/proc.h>
     84      1.1  wrstuden #include <sys/types.h>
     85      1.1  wrstuden #include <sys/vnode.h>
     86      1.1  wrstuden #include <sys/mount.h>
     87      1.1  wrstuden #include <sys/namei.h>
     88      1.1  wrstuden #include <sys/malloc.h>
     89      1.1  wrstuden #include <miscfs/overlay/overlay.h>
     90      1.1  wrstuden #include <miscfs/genfs/layer_extern.h>
     91      1.1  wrstuden 
     92      1.1  wrstuden int	ov_mount __P((struct mount *, const char *, void *,
     93      1.1  wrstuden 			  struct nameidata *, struct proc *));
     94      1.1  wrstuden int	ov_unmount __P((struct mount *, int, struct proc *));
     95      1.1  wrstuden 
     96      1.1  wrstuden #define	NOVERLAYNODECACHE	16
     97      1.1  wrstuden 
     98      1.1  wrstuden /*
     99      1.1  wrstuden  * Mount overlay layer
    100      1.1  wrstuden  */
    101      1.1  wrstuden int
    102      1.1  wrstuden ov_mount(mp, path, data, ndp, p)
    103      1.1  wrstuden 	struct mount *mp;
    104      1.1  wrstuden 	const char *path;
    105      1.1  wrstuden 	void *data;
    106      1.1  wrstuden 	struct nameidata *ndp;
    107      1.1  wrstuden 	struct proc *p;
    108      1.1  wrstuden {
    109      1.1  wrstuden 	int error = 0;
    110      1.1  wrstuden 	struct overlay_args args;
    111      1.1  wrstuden 	struct vnode *lowerrootvp, *vp;
    112      1.1  wrstuden 	struct overlay_mount *nmp;
    113      1.1  wrstuden 	struct layer_mount *lmp;
    114      1.1  wrstuden 	size_t size;
    115      1.1  wrstuden 
    116      1.1  wrstuden #ifdef OVERLAYFS_DIAGNOSTIC
    117      1.1  wrstuden 	printf("ov_mount(mp = %p)\n", mp);
    118      1.1  wrstuden #endif
    119      1.1  wrstuden 
    120      1.1  wrstuden 	/*
    121      1.1  wrstuden 	 * Get argument
    122      1.1  wrstuden 	 */
    123      1.1  wrstuden 	error = copyin(data, (caddr_t)&args, sizeof(struct overlay_args));
    124      1.1  wrstuden 	if (error)
    125      1.1  wrstuden 		return (error);
    126      1.1  wrstuden 
    127      1.1  wrstuden 	/*
    128      1.1  wrstuden 	 * Update only does export updating.
    129      1.1  wrstuden 	 */
    130      1.1  wrstuden 	if (mp->mnt_flag & MNT_UPDATE) {
    131      1.1  wrstuden 		lmp = MOUNTTOLAYERMOUNT(mp);
    132      1.1  wrstuden 		if (args.ova_target == 0)
    133      1.1  wrstuden 			return (vfs_export(mp, &lmp->layerm_export,
    134      1.1  wrstuden 					&args.la.export));
    135      1.1  wrstuden 		else
    136      1.1  wrstuden 			return (EOPNOTSUPP);
    137      1.1  wrstuden 	}
    138      1.1  wrstuden 
    139      1.1  wrstuden 	/*
    140      1.1  wrstuden 	 * Find lower node
    141      1.1  wrstuden 	 */
    142      1.1  wrstuden 	lowerrootvp = mp->mnt_vnodecovered;
    143      1.1  wrstuden 	if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY)))
    144      1.1  wrstuden 		return (error);
    145      1.1  wrstuden 
    146      1.1  wrstuden 	/*
    147      1.1  wrstuden 	 * First cut at fixing up upper mount point
    148      1.1  wrstuden 	 */
    149      1.1  wrstuden 	nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount),
    150      1.1  wrstuden 				M_UFSMNT, M_WAITOK);	/* XXX */
    151      1.1  wrstuden 	memset((caddr_t)nmp, 0, sizeof(struct overlay_mount));
    152      1.1  wrstuden 
    153      1.1  wrstuden 	mp->mnt_data = (qaddr_t) nmp;
    154      1.1  wrstuden 	nmp->ovm_vfs = lowerrootvp->v_mount;
    155      1.1  wrstuden 	if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL)
    156      1.1  wrstuden 		mp->mnt_flag |= MNT_LOCAL;
    157      1.1  wrstuden 
    158      1.1  wrstuden 	/*
    159      1.1  wrstuden 	 * Make sure that the mount point is sufficiently initialized
    160      1.1  wrstuden 	 * that the node create call will work.
    161      1.1  wrstuden 	 */
    162      1.4     assar 	vfs_getnewfsid(mp);
    163      1.1  wrstuden 
    164      1.1  wrstuden 	nmp->ovm_size = sizeof (struct overlay_node);
    165      1.1  wrstuden 	nmp->ovm_tag = VT_OVERLAY;
    166      1.1  wrstuden 	nmp->ovm_bypass = layer_bypass;
    167      1.1  wrstuden 	nmp->ovm_alloc = layer_node_alloc;	/* the default alloc is fine */
    168      1.1  wrstuden 	nmp->ovm_vnodeop_p = overlay_vnodeop_p;
    169      1.1  wrstuden 	simple_lock_init(&nmp->ovm_hashlock);
    170      1.5        ad 	nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE,
    171      1.5        ad 	    M_WAITOK, &nmp->ovm_node_hash);
    172      1.1  wrstuden 
    173      1.1  wrstuden 	/*
    174      1.1  wrstuden 	 * Fix up overlay node for root vnode
    175      1.1  wrstuden 	 */
    176      1.1  wrstuden 	error = layer_node_create(mp, lowerrootvp, &vp);
    177      1.1  wrstuden 	/*
    178      1.1  wrstuden 	 * Make sure the fixup worked
    179      1.1  wrstuden 	 */
    180      1.1  wrstuden 	if (error) {
    181      1.1  wrstuden 		vput(lowerrootvp);
    182      1.1  wrstuden 		free(nmp, M_UFSMNT);	/* XXX */
    183      1.1  wrstuden 		return (error);
    184      1.1  wrstuden 	}
    185      1.1  wrstuden 	/*
    186      1.1  wrstuden 	 * Unlock the node
    187      1.1  wrstuden 	 */
    188      1.1  wrstuden 	VOP_UNLOCK(vp, 0);
    189      1.1  wrstuden 
    190      1.1  wrstuden 	/*
    191      1.1  wrstuden 	 * Keep a held reference to the root vnode.
    192      1.1  wrstuden 	 * It is vrele'd in ov_unmount.
    193      1.1  wrstuden 	 */
    194      1.1  wrstuden 	vp->v_flag |= VROOT;
    195      1.1  wrstuden 	nmp->ovm_rootvp = vp;
    196      1.1  wrstuden 
    197      1.1  wrstuden 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    198      1.1  wrstuden 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
    199      1.1  wrstuden 	(void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
    200      1.1  wrstuden 	    &size);
    201      1.1  wrstuden 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
    202      1.1  wrstuden #ifdef OVERLAYFS_DIAGNOSTIC
    203      1.1  wrstuden 	printf("ov_mount: lower %s, alias at %s\n",
    204      1.1  wrstuden 	    mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
    205      1.1  wrstuden #endif
    206      1.1  wrstuden 	return (0);
    207      1.1  wrstuden }
    208      1.1  wrstuden 
    209      1.1  wrstuden /*
    210      1.1  wrstuden  * Free reference to overlay layer
    211      1.1  wrstuden  */
    212      1.1  wrstuden int
    213      1.1  wrstuden ov_unmount(mp, mntflags, p)
    214      1.1  wrstuden 	struct mount *mp;
    215      1.1  wrstuden 	int mntflags;
    216      1.1  wrstuden 	struct proc *p;
    217      1.1  wrstuden {
    218      1.1  wrstuden 	struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp;
    219      1.1  wrstuden 	int error;
    220      1.1  wrstuden 	int flags = 0;
    221      1.1  wrstuden 
    222      1.1  wrstuden #ifdef OVERLAYFS_DIAGNOSTIC
    223      1.1  wrstuden 	printf("ov_unmount(mp = %p)\n", mp);
    224      1.1  wrstuden #endif
    225      1.1  wrstuden 
    226      1.1  wrstuden 	if (mntflags & MNT_FORCE)
    227      1.1  wrstuden 		flags |= FORCECLOSE;
    228      1.1  wrstuden 
    229      1.1  wrstuden 	/*
    230      1.1  wrstuden 	 * Clear out buffer cache.  I don't think we
    231      1.1  wrstuden 	 * ever get anything cached at this level at the
    232      1.1  wrstuden 	 * moment, but who knows...
    233      1.1  wrstuden 	 */
    234      1.1  wrstuden #if 0
    235      1.1  wrstuden 	mntflushbuf(mp, 0);
    236      1.1  wrstuden 	if (mntinvalbuf(mp, 1))
    237      1.1  wrstuden 		return (EBUSY);
    238      1.1  wrstuden #endif
    239      1.1  wrstuden 	if (overlay_rootvp->v_usecount > 1)
    240      1.1  wrstuden 		return (EBUSY);
    241      1.1  wrstuden 	if ((error = vflush(mp, overlay_rootvp, flags)) != 0)
    242      1.1  wrstuden 		return (error);
    243      1.1  wrstuden 
    244      1.1  wrstuden #ifdef OVERLAYFS_DIAGNOSTIC
    245      1.1  wrstuden 	vprint("alias root of lower", overlay_rootvp);
    246      1.1  wrstuden #endif
    247      1.1  wrstuden 	/*
    248      1.1  wrstuden 	 * Release reference on underlying root vnode
    249      1.1  wrstuden 	 */
    250      1.1  wrstuden 	vrele(overlay_rootvp);
    251      1.1  wrstuden 	/*
    252      1.1  wrstuden 	 * And blow it away for future re-use
    253      1.1  wrstuden 	 */
    254      1.1  wrstuden 	vgone(overlay_rootvp);
    255      1.1  wrstuden 	/*
    256      1.1  wrstuden 	 * Finally, throw away the overlay_mount structure
    257      1.1  wrstuden 	 */
    258      1.1  wrstuden 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
    259      1.1  wrstuden 	mp->mnt_data = 0;
    260      1.1  wrstuden 	return 0;
    261      1.1  wrstuden }
    262      1.1  wrstuden 
    263      1.6  jdolecek extern const struct vnodeopv_desc overlay_vnodeop_opv_desc;
    264      1.1  wrstuden 
    265      1.6  jdolecek const struct vnodeopv_desc * const ov_vnodeopv_descs[] = {
    266      1.1  wrstuden 	&overlay_vnodeop_opv_desc,
    267      1.1  wrstuden 	NULL,
    268      1.1  wrstuden };
    269      1.1  wrstuden 
    270      1.1  wrstuden struct vfsops overlay_vfsops = {
    271      1.1  wrstuden 	MOUNT_OVERLAY,
    272      1.1  wrstuden 	ov_mount,
    273      1.1  wrstuden 	layerfs_start,
    274      1.1  wrstuden 	ov_unmount,
    275      1.1  wrstuden 	layerfs_root,
    276      1.1  wrstuden 	layerfs_quotactl,
    277      1.1  wrstuden 	layerfs_statfs,
    278      1.1  wrstuden 	layerfs_sync,
    279      1.1  wrstuden 	layerfs_vget,
    280      1.1  wrstuden 	layerfs_fhtovp,
    281      1.1  wrstuden 	layerfs_vptofh,
    282      1.1  wrstuden 	layerfs_init,
    283  1.7.4.1      fvdl 	NULL,
    284      1.3  jdolecek 	layerfs_done,
    285      1.1  wrstuden 	layerfs_sysctl,
    286      1.1  wrstuden 	NULL,				/* vfs_mountroot */
    287      1.1  wrstuden 	layerfs_checkexp,
    288      1.1  wrstuden 	ov_vnodeopv_descs,
    289      1.1  wrstuden };
    290