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umap_vfsops.c revision 1.34
      1 /*	$NetBSD: umap_vfsops.c,v 1.34 2002/07/30 07:40:11 soren Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software donated to Berkeley by
      8  * the UCLA Ficus project.
      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.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  *	from: @(#)null_vfsops.c       1.5 (Berkeley) 7/10/92
     39  *	@(#)umap_vfsops.c	8.8 (Berkeley) 5/14/95
     40  */
     41 
     42 /*
     43  * Umap Layer
     44  * (See mount_umap(8) for a description of this layer.)
     45  */
     46 
     47 #include <sys/cdefs.h>
     48 __KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.34 2002/07/30 07:40:11 soren Exp $");
     49 
     50 #include <sys/param.h>
     51 #include <sys/systm.h>
     52 #include <sys/proc.h>
     53 #include <sys/time.h>
     54 #include <sys/vnode.h>
     55 #include <sys/mount.h>
     56 #include <sys/namei.h>
     57 #include <sys/malloc.h>
     58 #include <miscfs/umapfs/umap.h>
     59 #include <miscfs/genfs/layer_extern.h>
     60 
     61 int	umapfs_mount __P((struct mount *, const char *, void *,
     62 			  struct nameidata *, struct proc *));
     63 int	umapfs_unmount __P((struct mount *, int, struct proc *));
     64 
     65 /*
     66  * Mount umap layer
     67  */
     68 int
     69 umapfs_mount(mp, path, data, ndp, p)
     70 	struct mount *mp;
     71 	const char *path;
     72 	void *data;
     73 	struct nameidata *ndp;
     74 	struct proc *p;
     75 {
     76 	struct umap_args args;
     77 	struct vnode *lowerrootvp, *vp;
     78 	struct umap_mount *amp;
     79 	size_t size;
     80 	int error;
     81 #ifdef UMAPFS_DIAGNOSTIC
     82 	int i;
     83 #endif
     84 
     85 	/* only for root */
     86 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
     87 		return error;
     88 
     89 #ifdef UMAPFS_DIAGNOSTIC
     90 	printf("umapfs_mount(mp = %p)\n", mp);
     91 #endif
     92 
     93 	/*
     94 	 * Get argument
     95 	 */
     96 	error = copyin(data, (caddr_t)&args, sizeof(struct umap_args));
     97 	if (error)
     98 		return (error);
     99 
    100 	/*
    101 	 * Update only does export updating.
    102 	 */
    103 	if (mp->mnt_flag & MNT_UPDATE) {
    104 		amp = MOUNTTOUMAPMOUNT(mp);
    105 		if (args.umap_target == 0)
    106 			return (vfs_export(mp, &amp->umapm_export,
    107 					&args.umap_export));
    108 		else
    109 			return (EOPNOTSUPP);
    110 	}
    111 
    112 	/*
    113 	 * Find lower node
    114 	 */
    115 	NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
    116 		UIO_USERSPACE, args.umap_target, p);
    117 	if ((error = namei(ndp)) != 0)
    118 		return (error);
    119 
    120 	/*
    121 	 * Sanity check on lower vnode
    122 	 */
    123 	lowerrootvp = ndp->ni_vp;
    124 #ifdef UMAPFS_DIAGNOSTIC
    125 	printf("vp = %p, check for VDIR...\n", lowerrootvp);
    126 #endif
    127 
    128 	if (lowerrootvp->v_type != VDIR) {
    129 		vput(lowerrootvp);
    130 		return (EINVAL);
    131 	}
    132 
    133 #ifdef UMAPFS_DIAGNOSTIC
    134 	printf("mp = %p\n", mp);
    135 #endif
    136 
    137 	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
    138 				M_UFSMNT, M_WAITOK);	/* XXX */
    139 	memset((caddr_t)amp, 0, sizeof(struct umap_mount));
    140 
    141 	mp->mnt_data = amp;
    142 	amp->umapm_vfs = lowerrootvp->v_mount;
    143 	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
    144 		mp->mnt_flag |= MNT_LOCAL;
    145 
    146 	/*
    147 	 * Now copy in the number of entries and maps for umap mapping.
    148 	 */
    149 	if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) {
    150 		vput(lowerrootvp);
    151 		return (error);
    152 	}
    153 
    154 	amp->info_nentries = args.nentries;
    155 	amp->info_gnentries = args.gnentries;
    156 	error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
    157 	    2*sizeof(u_long)*args.nentries);
    158 	if (error) {
    159 		vput(lowerrootvp);
    160 		return (error);
    161 	}
    162 
    163 #ifdef UMAPFS_DIAGNOSTIC
    164 	printf("umap_mount:nentries %d\n",args.nentries);
    165 	for (i = 0; i < args.nentries; i++)
    166 		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
    167 	 	    amp->info_mapdata[i][1]);
    168 #endif
    169 
    170 	error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
    171 	    2*sizeof(u_long)*args.gnentries);
    172 	if (error) {
    173 		vput(lowerrootvp);
    174 		return (error);
    175 	}
    176 
    177 #ifdef UMAPFS_DIAGNOSTIC
    178 	printf("umap_mount:gnentries %d\n",args.gnentries);
    179 	for (i = 0; i < args.gnentries; i++)
    180 		printf("\tgroup %ld maps to %ld\n",
    181 		    amp->info_gmapdata[i][0],
    182 	 	    amp->info_gmapdata[i][1]);
    183 #endif
    184 
    185 	/*
    186 	 * Make sure the mount point's sufficiently initialized
    187 	 * that the node create call will work.
    188 	 */
    189 	vfs_getnewfsid(mp);
    190 	amp->umapm_size = sizeof(struct umap_node);
    191 	amp->umapm_tag = VT_UMAP;
    192 	amp->umapm_bypass = umap_bypass;
    193 	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
    194 	amp->umapm_vnodeop_p = umap_vnodeop_p;
    195 	simple_lock_init(&amp->umapm_hashlock);
    196 	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
    197 	    M_WAITOK, &amp->umapm_node_hash);
    198 
    199 
    200 	/*
    201 	 * fix up umap node for root vnode.
    202 	 */
    203 	error = layer_node_create(mp, lowerrootvp, &vp);
    204 	/*
    205 	 * Make sure the node alias worked
    206 	 */
    207 	if (error) {
    208 		vput(lowerrootvp);
    209 		free(amp, M_UFSMNT);	/* XXX */
    210 		return (error);
    211 	}
    212 	/*
    213 	 * Unlock the node (either the lower or the alias)
    214 	 */
    215 	VOP_UNLOCK(vp, 0);
    216 
    217 	/*
    218 	 * Keep a held reference to the root vnode.
    219 	 * It is vrele'd in umapfs_unmount.
    220 	 */
    221 	vp->v_flag |= VROOT;
    222 	amp->umapm_rootvp = vp;
    223 
    224 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    225 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
    226 	(void) copyinstr(args.umap_target, mp->mnt_stat.f_mntfromname,
    227 		MNAMELEN - 1, &size);
    228 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
    229 #ifdef UMAPFS_DIAGNOSTIC
    230 	printf("umapfs_mount: lower %s, alias at %s\n",
    231 		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
    232 #endif
    233 	return (0);
    234 }
    235 
    236 /*
    237  * Free reference to umap layer
    238  */
    239 int
    240 umapfs_unmount(mp, mntflags, p)
    241 	struct mount *mp;
    242 	int mntflags;
    243 	struct proc *p;
    244 {
    245 	struct vnode *rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
    246 	int error;
    247 	int flags = 0;
    248 
    249 #ifdef UMAPFS_DIAGNOSTIC
    250 	printf("umapfs_unmount(mp = %p)\n", mp);
    251 #endif
    252 
    253 	if (mntflags & MNT_FORCE)
    254 		flags |= FORCECLOSE;
    255 
    256 	/*
    257 	 * Clear out buffer cache.  I don't think we
    258 	 * ever get anything cached at this level at the
    259 	 * moment, but who knows...
    260 	 */
    261 #ifdef notyet
    262 	mntflushbuf(mp, 0);
    263 	if (mntinvalbuf(mp, 1))
    264 		return (EBUSY);
    265 #endif
    266 	if (rootvp->v_usecount > 1)
    267 		return (EBUSY);
    268 	if ((error = vflush(mp, rootvp, flags)) != 0)
    269 		return (error);
    270 
    271 #ifdef UMAPFS_DIAGNOSTIC
    272 	vprint("alias root of lower", rootvp);
    273 #endif
    274 	/*
    275 	 * Release reference on underlying root vnode
    276 	 */
    277 	vrele(rootvp);
    278 	/*
    279 	 * And blow it away for future re-use
    280 	 */
    281 	vgone(rootvp);
    282 	/*
    283 	 * Finally, throw away the umap_mount structure
    284 	 */
    285 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
    286 	mp->mnt_data = 0;
    287 	return (0);
    288 }
    289 
    290 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
    291 
    292 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
    293 	&umapfs_vnodeop_opv_desc,
    294 	NULL,
    295 };
    296 
    297 struct vfsops umapfs_vfsops = {
    298 	MOUNT_UMAP,
    299 	umapfs_mount,
    300 	layerfs_start,
    301 	umapfs_unmount,
    302 	layerfs_root,
    303 	layerfs_quotactl,
    304 	layerfs_statfs,
    305 	layerfs_sync,
    306 	layerfs_vget,
    307 	layerfs_fhtovp,
    308 	layerfs_vptofh,
    309 	layerfs_init,
    310 	NULL,
    311 	layerfs_done,
    312 	layerfs_sysctl,
    313 	NULL,				/* vfs_mountroot */
    314 	layerfs_checkexp,
    315 	umapfs_vnodeopv_descs,
    316 };
    317