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umap_vfsops.c revision 1.35
      1 /*	$NetBSD: umap_vfsops.c,v 1.35 2002/09/21 18:09:31 christos 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 1.35 2002/09/21 18:09:31 christos 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 	if (mp->mnt_flag & MNT_GETARGS) {
     85 		amp = MOUNTTOUMAPMOUNT(mp);
     86 		if (amp == NULL)
     87 			return EIO;
     88 		args.la.target = NULL;
     89 		vfs_showexport(mp, &args.la.export, &amp->umapm_export);
     90 		args.nentries = amp->info_nentries;
     91 		args.gnentries = amp->info_gnentries;
     92 		return copyout(&args, data, sizeof(args));
     93 	}
     94 
     95 	/* only for root */
     96 	if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
     97 		return error;
     98 
     99 #ifdef UMAPFS_DIAGNOSTIC
    100 	printf("umapfs_mount(mp = %p)\n", mp);
    101 #endif
    102 
    103 	/*
    104 	 * Get argument
    105 	 */
    106 	error = copyin(data, (caddr_t)&args, sizeof(struct umap_args));
    107 	if (error)
    108 		return (error);
    109 
    110 	/*
    111 	 * Update only does export updating.
    112 	 */
    113 	if (mp->mnt_flag & MNT_UPDATE) {
    114 		amp = MOUNTTOUMAPMOUNT(mp);
    115 		if (args.umap_target == 0)
    116 			return (vfs_export(mp, &amp->umapm_export,
    117 					&args.umap_export));
    118 		else
    119 			return (EOPNOTSUPP);
    120 	}
    121 
    122 	/*
    123 	 * Find lower node
    124 	 */
    125 	NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
    126 		UIO_USERSPACE, args.umap_target, p);
    127 	if ((error = namei(ndp)) != 0)
    128 		return (error);
    129 
    130 	/*
    131 	 * Sanity check on lower vnode
    132 	 */
    133 	lowerrootvp = ndp->ni_vp;
    134 #ifdef UMAPFS_DIAGNOSTIC
    135 	printf("vp = %p, check for VDIR...\n", lowerrootvp);
    136 #endif
    137 
    138 	if (lowerrootvp->v_type != VDIR) {
    139 		vput(lowerrootvp);
    140 		return (EINVAL);
    141 	}
    142 
    143 #ifdef UMAPFS_DIAGNOSTIC
    144 	printf("mp = %p\n", mp);
    145 #endif
    146 
    147 	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
    148 				M_UFSMNT, M_WAITOK);	/* XXX */
    149 	memset((caddr_t)amp, 0, sizeof(struct umap_mount));
    150 
    151 	mp->mnt_data = amp;
    152 	amp->umapm_vfs = lowerrootvp->v_mount;
    153 	if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
    154 		mp->mnt_flag |= MNT_LOCAL;
    155 
    156 	/*
    157 	 * Now copy in the number of entries and maps for umap mapping.
    158 	 */
    159 	if (args.nentries > MAPFILEENTRIES || args.gnentries > GMAPFILEENTRIES) {
    160 		vput(lowerrootvp);
    161 		return (error);
    162 	}
    163 
    164 	amp->info_nentries = args.nentries;
    165 	amp->info_gnentries = args.gnentries;
    166 	error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
    167 	    2*sizeof(u_long)*args.nentries);
    168 	if (error) {
    169 		vput(lowerrootvp);
    170 		return (error);
    171 	}
    172 
    173 #ifdef UMAPFS_DIAGNOSTIC
    174 	printf("umap_mount:nentries %d\n",args.nentries);
    175 	for (i = 0; i < args.nentries; i++)
    176 		printf("   %ld maps to %ld\n", amp->info_mapdata[i][0],
    177 	 	    amp->info_mapdata[i][1]);
    178 #endif
    179 
    180 	error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
    181 	    2*sizeof(u_long)*args.gnentries);
    182 	if (error) {
    183 		vput(lowerrootvp);
    184 		return (error);
    185 	}
    186 
    187 #ifdef UMAPFS_DIAGNOSTIC
    188 	printf("umap_mount:gnentries %d\n",args.gnentries);
    189 	for (i = 0; i < args.gnentries; i++)
    190 		printf("\tgroup %ld maps to %ld\n",
    191 		    amp->info_gmapdata[i][0],
    192 	 	    amp->info_gmapdata[i][1]);
    193 #endif
    194 
    195 	/*
    196 	 * Make sure the mount point's sufficiently initialized
    197 	 * that the node create call will work.
    198 	 */
    199 	vfs_getnewfsid(mp);
    200 	amp->umapm_size = sizeof(struct umap_node);
    201 	amp->umapm_tag = VT_UMAP;
    202 	amp->umapm_bypass = umap_bypass;
    203 	amp->umapm_alloc = layer_node_alloc;	/* the default alloc is fine */
    204 	amp->umapm_vnodeop_p = umap_vnodeop_p;
    205 	simple_lock_init(&amp->umapm_hashlock);
    206 	amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, M_CACHE,
    207 	    M_WAITOK, &amp->umapm_node_hash);
    208 
    209 
    210 	/*
    211 	 * fix up umap node for root vnode.
    212 	 */
    213 	error = layer_node_create(mp, lowerrootvp, &vp);
    214 	/*
    215 	 * Make sure the node alias worked
    216 	 */
    217 	if (error) {
    218 		vput(lowerrootvp);
    219 		free(amp, M_UFSMNT);	/* XXX */
    220 		return (error);
    221 	}
    222 	/*
    223 	 * Unlock the node (either the lower or the alias)
    224 	 */
    225 	VOP_UNLOCK(vp, 0);
    226 
    227 	/*
    228 	 * Keep a held reference to the root vnode.
    229 	 * It is vrele'd in umapfs_unmount.
    230 	 */
    231 	vp->v_flag |= VROOT;
    232 	amp->umapm_rootvp = vp;
    233 
    234 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    235 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
    236 	(void) copyinstr(args.umap_target, mp->mnt_stat.f_mntfromname,
    237 		MNAMELEN - 1, &size);
    238 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
    239 #ifdef UMAPFS_DIAGNOSTIC
    240 	printf("umapfs_mount: lower %s, alias at %s\n",
    241 		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
    242 #endif
    243 	return (0);
    244 }
    245 
    246 /*
    247  * Free reference to umap layer
    248  */
    249 int
    250 umapfs_unmount(mp, mntflags, p)
    251 	struct mount *mp;
    252 	int mntflags;
    253 	struct proc *p;
    254 {
    255 	struct vnode *rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
    256 	int error;
    257 	int flags = 0;
    258 
    259 #ifdef UMAPFS_DIAGNOSTIC
    260 	printf("umapfs_unmount(mp = %p)\n", mp);
    261 #endif
    262 
    263 	if (mntflags & MNT_FORCE)
    264 		flags |= FORCECLOSE;
    265 
    266 	/*
    267 	 * Clear out buffer cache.  I don't think we
    268 	 * ever get anything cached at this level at the
    269 	 * moment, but who knows...
    270 	 */
    271 #ifdef notyet
    272 	mntflushbuf(mp, 0);
    273 	if (mntinvalbuf(mp, 1))
    274 		return (EBUSY);
    275 #endif
    276 	if (rootvp->v_usecount > 1)
    277 		return (EBUSY);
    278 	if ((error = vflush(mp, rootvp, flags)) != 0)
    279 		return (error);
    280 
    281 #ifdef UMAPFS_DIAGNOSTIC
    282 	vprint("alias root of lower", rootvp);
    283 #endif
    284 	/*
    285 	 * Release reference on underlying root vnode
    286 	 */
    287 	vrele(rootvp);
    288 	/*
    289 	 * And blow it away for future re-use
    290 	 */
    291 	vgone(rootvp);
    292 	/*
    293 	 * Finally, throw away the umap_mount structure
    294 	 */
    295 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
    296 	mp->mnt_data = 0;
    297 	return (0);
    298 }
    299 
    300 extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
    301 
    302 const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
    303 	&umapfs_vnodeop_opv_desc,
    304 	NULL,
    305 };
    306 
    307 struct vfsops umapfs_vfsops = {
    308 	MOUNT_UMAP,
    309 	umapfs_mount,
    310 	layerfs_start,
    311 	umapfs_unmount,
    312 	layerfs_root,
    313 	layerfs_quotactl,
    314 	layerfs_statfs,
    315 	layerfs_sync,
    316 	layerfs_vget,
    317 	layerfs_fhtovp,
    318 	layerfs_vptofh,
    319 	layerfs_init,
    320 	NULL,
    321 	layerfs_done,
    322 	layerfs_sysctl,
    323 	NULL,				/* vfs_mountroot */
    324 	layerfs_checkexp,
    325 	umapfs_vnodeopv_descs,
    326 };
    327