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umap_vfsops.c revision 1.29
      1 /*	$NetBSD: umap_vfsops.c,v 1.29 2001/08/03 06:00:13 jdolecek 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/param.h>
     48 #include <sys/systm.h>
     49 #include <sys/proc.h>
     50 #include <sys/time.h>
     51 #include <sys/types.h>
     52 #include <sys/vnode.h>
     53 #include <sys/mount.h>
     54 #include <sys/namei.h>
     55 #include <sys/malloc.h>
     56 #include <miscfs/umapfs/umap.h>
     57 #include <miscfs/genfs/layer_extern.h>
     58 
     59 int	umapfs_mount __P((struct mount *, const char *, void *,
     60 			  struct nameidata *, struct proc *));
     61 int	umapfs_unmount __P((struct mount *, int, struct proc *));
     62 
     63 /*
     64  * Mount umap layer
     65  */
     66 int
     67 umapfs_mount(mp, path, data, ndp, p)
     68 	struct mount *mp;
     69 	const char *path;
     70 	void *data;
     71 	struct nameidata *ndp;
     72 	struct proc *p;
     73 {
     74 	struct umap_args args;
     75 	struct vnode *lowerrootvp, *vp;
     76 	struct umap_mount *amp;
     77 	size_t size;
     78 	int error;
     79 #ifdef UMAPFS_DIAGNOSTIC
     80 	int i;
     81 #endif
     82 
     83 	/* only for root */
     84 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
     85 		return error;
     86 
     87 #ifdef UMAPFS_DIAGNOSTIC
     88 	printf("umapfs_mount(mp = %p)\n", mp);
     89 #endif
     90 
     91 	/*
     92 	 * Get argument
     93 	 */
     94 	error = copyin(data, (caddr_t)&args, sizeof(struct umap_args));
     95 	if (error)
     96 		return (error);
     97 
     98 	/*
     99 	 * Update only does export updating.
    100 	 */
    101 	if (mp->mnt_flag & MNT_UPDATE) {
    102 		amp = MOUNTTOUMAPMOUNT(mp);
    103 		if (args.umap_target == 0)
    104 			return (vfs_export(mp, &amp->umapm_export,
    105 					&args.umap_export));
    106 		else
    107 			return (EOPNOTSUPP);
    108 	}
    109 
    110 	/*
    111 	 * Find lower node
    112 	 */
    113 	NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
    114 		UIO_USERSPACE, args.umap_target, p);
    115 	if ((error = namei(ndp)) != 0)
    116 		return (error);
    117 
    118 	/*
    119 	 * Sanity check on lower vnode
    120 	 */
    121 	lowerrootvp = ndp->ni_vp;
    122 #ifdef UMAPFS_DIAGNOSTIC
    123 	printf("vp = %p, check for VDIR...\n", lowerrootvp);
    124 #endif
    125 
    126 	if (lowerrootvp->v_type != VDIR) {
    127 		vput(lowerrootvp);
    128 		return (EINVAL);
    129 	}
    130 
    131 #ifdef UMAPFS_DIAGNOSTIC
    132 	printf("mp = %p\n", mp);
    133 #endif
    134 
    135 	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
    136 				M_UFSMNT, M_WAITOK);	/* XXX */
    137 	memset((caddr_t)amp, 0, sizeof(struct umap_mount));
    138 
    139 	mp->mnt_data = (qaddr_t) amp;
    140 	amp->umapm_vfs = lowerrootvp->v_mount;
    141 	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
    142 		mp->mnt_flag |= MNT_LOCAL;
    143 
    144 	/*
    145 	 * Now copy in the number of entries and maps for umap mapping.
    146 	 */
    147 	if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES){
    148 		vput(lowerrootvp);
    149 		return (error);
    150 	}
    151 
    152 	amp->info_nentries = args.nentries;
    153 	amp->info_gnentries = args.gnentries;
    154 	error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
    155 	    2*sizeof(u_long)*args.nentries);
    156 	if (error) {
    157 		vput(lowerrootvp);
    158 		return (error);
    159 	}
    160 
    161 #ifdef UMAPFS_DIAGNOSTIC
    162 	printf("umap_mount:nentries %d\n",args.nentries);
    163 	for (i = 0; i < args.nentries; i++)
    164 		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
    165 	 	    amp->info_mapdata[i][1]);
    166 #endif
    167 
    168 	error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
    169 	    2*sizeof(u_long)*args.gnentries);
    170 	if (error) {
    171 		vput(lowerrootvp);
    172 		return (error);
    173 	}
    174 
    175 #ifdef UMAPFS_DIAGNOSTIC
    176 	printf("umap_mount:gnentries %d\n",args.gnentries);
    177 	for (i = 0; i < args.gnentries; i++)
    178 		printf("\tgroup %ld maps to %ld\n",
    179 		    amp->info_gmapdata[i][0],
    180 	 	    amp->info_gmapdata[i][1]);
    181 #endif
    182 
    183 	/*
    184 	 * Make sure the mount point's sufficiently initialized
    185 	 * that the node create call will work.
    186 	 */
    187 	vfs_getnewfsid(mp);
    188 	amp->umapm_size = sizeof(struct umap_node);
    189 	amp->umapm_tag = VT_UMAP;
    190 	amp->umapm_bypass = umap_bypass;
    191 	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
    192 	amp->umapm_vnodeop_p = umap_vnodeop_p;
    193 	simple_lock_init(&amp->umapm_hashlock);
    194 	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
    195 	    M_WAITOK, &amp->umapm_node_hash);
    196 
    197 
    198 	/*
    199 	 * fix up umap node for root vnode.
    200 	 */
    201 	error = layer_node_create(mp, lowerrootvp, &vp);
    202 	/*
    203 	 * Make sure the node alias worked
    204 	 */
    205 	if (error) {
    206 		vput(lowerrootvp);
    207 		free(amp, M_UFSMNT);	/* XXX */
    208 		return (error);
    209 	}
    210 	/*
    211 	 * Unlock the node (either the lower or the alias)
    212 	 */
    213 	VOP_UNLOCK(vp, 0);
    214 
    215 	/*
    216 	 * Keep a held reference to the root vnode.
    217 	 * It is vrele'd in umapfs_unmount.
    218 	 */
    219 	vp->v_flag |= VROOT;
    220 	amp->umapm_rootvp = vp;
    221 
    222 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    223 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
    224 	(void) copyinstr(args.umap_target, mp->mnt_stat.f_mntfromname,
    225 		MNAMELEN - 1, &size);
    226 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
    227 #ifdef UMAPFS_DIAGNOSTIC
    228 	printf("umapfs_mount: lower %s, alias at %s\n",
    229 		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
    230 #endif
    231 	return (0);
    232 }
    233 
    234 /*
    235  * Free reference to umap layer
    236  */
    237 int
    238 umapfs_unmount(mp, mntflags, p)
    239 	struct mount *mp;
    240 	int mntflags;
    241 	struct proc *p;
    242 {
    243 	struct vnode *rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
    244 	int error;
    245 	int flags = 0;
    246 
    247 #ifdef UMAPFS_DIAGNOSTIC
    248 	printf("umapfs_unmount(mp = %p)\n", mp);
    249 #endif
    250 
    251 	if (mntflags & MNT_FORCE)
    252 		flags |= FORCECLOSE;
    253 
    254 	/*
    255 	 * Clear out buffer cache.  I don't think we
    256 	 * ever get anything cached at this level at the
    257 	 * moment, but who knows...
    258 	 */
    259 #ifdef notyet
    260 	mntflushbuf(mp, 0);
    261 	if (mntinvalbuf(mp, 1))
    262 		return (EBUSY);
    263 #endif
    264 	if (rootvp->v_usecount > 1)
    265 		return (EBUSY);
    266 	if ((error = vflush(mp, rootvp, flags)) != 0)
    267 		return (error);
    268 
    269 #ifdef UMAPFS_DIAGNOSTIC
    270 	vprint("alias root of lower", rootvp);
    271 #endif
    272 	/*
    273 	 * Release reference on underlying root vnode
    274 	 */
    275 	vrele(rootvp);
    276 	/*
    277 	 * And blow it away for future re-use
    278 	 */
    279 	vgone(rootvp);
    280 	/*
    281 	 * Finally, throw away the umap_mount structure
    282 	 */
    283 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
    284 	mp->mnt_data = 0;
    285 	return (0);
    286 }
    287 
    288 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
    289 
    290 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
    291 	&umapfs_vnodeop_opv_desc,
    292 	NULL,
    293 };
    294 
    295 struct vfsops umapfs_vfsops = {
    296 	MOUNT_UMAP,
    297 	umapfs_mount,
    298 	layerfs_start,
    299 	umapfs_unmount,
    300 	layerfs_root,
    301 	layerfs_quotactl,
    302 	layerfs_statfs,
    303 	layerfs_sync,
    304 	layerfs_vget,
    305 	layerfs_fhtovp,
    306 	layerfs_vptofh,
    307 	layerfs_init,
    308 	layerfs_done,
    309 	layerfs_sysctl,
    310 	NULL,				/* vfs_mountroot */
    311 	layerfs_checkexp,
    312 	umapfs_vnodeopv_descs,
    313 };
    314