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kernfs_vfsops.c revision 1.87
      1 /*	$NetBSD: kernfs_vfsops.c,v 1.87 2008/12/17 20:51:36 cegger Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993, 1995
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software donated to Berkeley by
      8  * Jan-Simon Pendry.
      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. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  *
     34  *	@(#)kernfs_vfsops.c	8.10 (Berkeley) 5/14/95
     35  */
     36 
     37 /*
     38  * Kernel params Filesystem
     39  */
     40 
     41 #include <sys/cdefs.h>
     42 __KERNEL_RCSID(0, "$NetBSD: kernfs_vfsops.c,v 1.87 2008/12/17 20:51:36 cegger Exp $");
     43 
     44 #ifdef _KERNEL_OPT
     45 #include "opt_compat_netbsd.h"
     46 #endif
     47 
     48 #include <sys/param.h>
     49 #include <sys/systm.h>
     50 #include <sys/sysctl.h>
     51 #include <sys/conf.h>
     52 #include <sys/proc.h>
     53 #include <sys/vnode.h>
     54 #include <sys/mount.h>
     55 #include <sys/namei.h>
     56 #include <sys/dirent.h>
     57 #include <sys/malloc.h>
     58 #include <sys/syslog.h>
     59 #include <sys/kauth.h>
     60 #include <sys/module.h>
     61 
     62 #include <miscfs/genfs/genfs.h>
     63 #include <miscfs/specfs/specdev.h>
     64 #include <miscfs/kernfs/kernfs.h>
     65 
     66 MODULE(MODULE_CLASS_VFS, kernfs, NULL);
     67 
     68 MALLOC_JUSTDEFINE(M_KERNFSMNT, "kernfs mount", "kernfs mount structures");
     69 
     70 dev_t rrootdev = NODEV;
     71 
     72 VFS_PROTOS(kernfs);
     73 
     74 void	kernfs_get_rrootdev(void);
     75 
     76 static struct sysctllog *kernfs_sysctl_log;
     77 
     78 void
     79 kernfs_init()
     80 {
     81 
     82 	malloc_type_attach(M_KERNFSMNT);
     83 	kernfs_hashinit();
     84 }
     85 
     86 void
     87 kernfs_reinit()
     88 {
     89 	kernfs_hashreinit();
     90 }
     91 
     92 void
     93 kernfs_done()
     94 {
     95 
     96 	kernfs_hashdone();
     97 	malloc_type_detach(M_KERNFSMNT);
     98 }
     99 
    100 void
    101 kernfs_get_rrootdev()
    102 {
    103 	static int tried = 0;
    104 
    105 	if (tried) {
    106 		/* Already did it once. */
    107 		return;
    108 	}
    109 	tried = 1;
    110 
    111 	if (rootdev == NODEV)
    112 		return;
    113 	rrootdev = devsw_blk2chr(rootdev);
    114 	if (rrootdev != NODEV)
    115 		return;
    116 	rrootdev = NODEV;
    117 	printf("kernfs_get_rrootdev: no raw root device\n");
    118 }
    119 
    120 /*
    121  * Mount the Kernel params filesystem
    122  */
    123 int
    124 kernfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
    125 {
    126 	struct lwp *l = curlwp;
    127 	int error = 0;
    128 	struct kernfs_mount *fmp;
    129 
    130 	if (UIO_MX & (UIO_MX - 1)) {
    131 		log(LOG_ERR, "kernfs: invalid directory entry size");
    132 		return (EINVAL);
    133 	}
    134 
    135 	if (mp->mnt_flag & MNT_GETARGS) {
    136 		*data_len = 0;
    137 		return 0;
    138 	}
    139 	/*
    140 	 * Update is a no-op
    141 	 */
    142 	if (mp->mnt_flag & MNT_UPDATE)
    143 		return (EOPNOTSUPP);
    144 
    145 	fmp = malloc(sizeof(struct kernfs_mount), M_KERNFSMNT, M_WAITOK|M_ZERO);
    146 	TAILQ_INIT(&fmp->nodelist);
    147 
    148 	mp->mnt_stat.f_namemax = MAXNAMLEN;
    149 	mp->mnt_flag |= MNT_LOCAL;
    150 	mp->mnt_data = fmp;
    151 	vfs_getnewfsid(mp);
    152 
    153 	if ((error = set_statvfs_info(path, UIO_USERSPACE, "kernfs",
    154 	    UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) {
    155 		free(fmp, M_KERNFSMNT);
    156 		return error;
    157 	}
    158 
    159 	kernfs_get_rrootdev();
    160 	return 0;
    161 }
    162 
    163 int
    164 kernfs_start(struct mount *mp, int flags)
    165 {
    166 
    167 	return (0);
    168 }
    169 
    170 int
    171 kernfs_unmount(struct mount *mp, int mntflags)
    172 {
    173 	int error;
    174 	int flags = 0;
    175 
    176 	if (mntflags & MNT_FORCE)
    177 		flags |= FORCECLOSE;
    178 
    179 	if ((error = vflush(mp, 0, flags)) != 0)
    180 		return (error);
    181 
    182 	/*
    183 	 * Finally, throw away the kernfs_mount structure
    184 	 */
    185 	free(mp->mnt_data, M_KERNFSMNT);
    186 	mp->mnt_data = NULL;
    187 	return (0);
    188 }
    189 
    190 int
    191 kernfs_root(mp, vpp)
    192 	struct mount *mp;
    193 	struct vnode **vpp;
    194 {
    195 
    196 	/* setup "." */
    197 	return (kernfs_allocvp(mp, vpp, KFSkern, &kern_targets[0], 0));
    198 }
    199 
    200 int
    201 kernfs_statvfs(struct mount *mp, struct statvfs *sbp)
    202 {
    203 
    204 	sbp->f_bsize = DEV_BSIZE;
    205 	sbp->f_frsize = DEV_BSIZE;
    206 	sbp->f_iosize = DEV_BSIZE;
    207 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    208 	sbp->f_bfree = 0;
    209 	sbp->f_bavail = 0;
    210 	sbp->f_bresvd = 0;
    211 	sbp->f_files = 1024;	/* XXX lie */
    212 	sbp->f_ffree = 128;	/* XXX lie */
    213 	sbp->f_favail = 128;	/* XXX lie */
    214 	sbp->f_fresvd = 0;
    215 	copy_statvfs_info(sbp, mp);
    216 	return (0);
    217 }
    218 
    219 /*ARGSUSED*/
    220 int
    221 kernfs_sync(struct mount *mp, int waitfor,
    222     kauth_cred_t uc)
    223 {
    224 
    225 	return (0);
    226 }
    227 
    228 /*
    229  * Kernfs flat namespace lookup.
    230  * Currently unsupported.
    231  */
    232 int
    233 kernfs_vget(struct mount *mp, ino_t ino,
    234     struct vnode **vpp)
    235 {
    236 
    237 	return (EOPNOTSUPP);
    238 }
    239 
    240 extern const struct vnodeopv_desc kernfs_vnodeop_opv_desc;
    241 
    242 const struct vnodeopv_desc * const kernfs_vnodeopv_descs[] = {
    243 	&kernfs_vnodeop_opv_desc,
    244 	NULL,
    245 };
    246 
    247 struct vfsops kernfs_vfsops = {
    248 	MOUNT_KERNFS,
    249 	0,
    250 	kernfs_mount,
    251 	kernfs_start,
    252 	kernfs_unmount,
    253 	kernfs_root,
    254 	(void *)eopnotsupp,		/* vfs_quotactl */
    255 	kernfs_statvfs,
    256 	kernfs_sync,
    257 	kernfs_vget,
    258 	(void *)eopnotsupp,		/* vfs_fhtovp */
    259 	(void *)eopnotsupp,		/* vfs_vptofh */
    260 	kernfs_init,
    261 	kernfs_reinit,
    262 	kernfs_done,
    263 	NULL,				/* vfs_mountroot */
    264 	(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
    265 	vfs_stdextattrctl,
    266 	(void *)eopnotsupp,		/* vfs_suspendctl */
    267 	genfs_renamelock_enter,
    268 	genfs_renamelock_exit,
    269 	(void *)eopnotsupp,
    270 	kernfs_vnodeopv_descs,
    271 	0,
    272 	{ NULL, NULL },
    273 };
    274 
    275 static int
    276 kernfs_modcmd(modcmd_t cmd, void *arg)
    277 {
    278 	int error;
    279 
    280 	switch (cmd) {
    281 	case MODULE_CMD_INIT:
    282 		error = vfs_attach(&kernfs_vfsops);
    283 		if (error != 0)
    284 			break;
    285 		sysctl_createv(&kernfs_sysctl_log, 0, NULL, NULL,
    286 			       CTLFLAG_PERMANENT,
    287 			       CTLTYPE_NODE, "vfs", NULL,
    288 			       NULL, 0, NULL, 0,
    289 			       CTL_VFS, CTL_EOL);
    290 		sysctl_createv(&kernfs_sysctl_log, 0, NULL, NULL,
    291 			       CTLFLAG_PERMANENT,
    292 			       CTLTYPE_NODE, "kernfs",
    293 			       SYSCTL_DESCR("/kern file system"),
    294 			       NULL, 0, NULL, 0,
    295 			       CTL_VFS, 11, CTL_EOL);
    296 		/*
    297 		 * XXX the "11" above could be dynamic, thereby eliminating one
    298 		 * more instance of the "number to vfs" mapping problem, but
    299 		 * "11" is the order as taken from sys/mount.h
    300 		 */
    301 		break;
    302 	case MODULE_CMD_FINI:
    303 		error = vfs_detach(&kernfs_vfsops);
    304 		if (error != 0)
    305 			break;
    306 		sysctl_teardown(&kernfs_sysctl_log);
    307 		break;
    308 	default:
    309 		error = ENOTTY;
    310 		break;
    311 	}
    312 
    313 	return (error);
    314 }
    315