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mfs_vfsops.c revision 1.34
      1 /*	$NetBSD: mfs_vfsops.c,v 1.34 2001/05/30 11:57:19 mrg Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1989, 1990, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)mfs_vfsops.c	8.11 (Berkeley) 6/19/95
     36  */
     37 
     38 #if defined(_KERNEL_OPT)
     39 #include "opt_compat_netbsd.h"
     40 #endif
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/time.h>
     45 #include <sys/kernel.h>
     46 #include <sys/proc.h>
     47 #include <sys/buf.h>
     48 #include <sys/mount.h>
     49 #include <sys/signalvar.h>
     50 #include <sys/vnode.h>
     51 #include <sys/malloc.h>
     52 
     53 #include <miscfs/syncfs/syncfs.h>
     54 
     55 #include <ufs/ufs/quota.h>
     56 #include <ufs/ufs/inode.h>
     57 #include <ufs/ufs/ufsmount.h>
     58 #include <ufs/ufs/ufs_extern.h>
     59 
     60 #include <ufs/ffs/fs.h>
     61 #include <ufs/ffs/ffs_extern.h>
     62 
     63 #include <ufs/mfs/mfsnode.h>
     64 #include <ufs/mfs/mfs_extern.h>
     65 
     66 caddr_t	mfs_rootbase;	/* address of mini-root in kernel virtual memory */
     67 u_long	mfs_rootsize;	/* size of mini-root in bytes */
     68 
     69 static	int mfs_minor;	/* used for building internal dev_t */
     70 
     71 extern int (**mfs_vnodeop_p) __P((void *));
     72 
     73 /*
     74  * mfs vfs operations.
     75  */
     76 
     77 extern const struct vnodeopv_desc mfs_vnodeop_opv_desc;
     78 
     79 const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = {
     80 	&mfs_vnodeop_opv_desc,
     81 	NULL,
     82 };
     83 
     84 struct vfsops mfs_vfsops = {
     85 	MOUNT_MFS,
     86 	mfs_mount,
     87 	mfs_start,
     88 	ffs_unmount,
     89 	ufs_root,
     90 	ufs_quotactl,
     91 	mfs_statfs,
     92 	ffs_sync,
     93 	ffs_vget,
     94 	ffs_fhtovp,
     95 	ffs_vptofh,
     96 	mfs_init,
     97 	mfs_done,
     98 	ffs_sysctl,
     99 	NULL,
    100 	ufs_check_export,
    101 	mfs_vnodeopv_descs,
    102 };
    103 
    104 /*
    105  * Memory based filesystem initialization.
    106  */
    107 void
    108 mfs_init()
    109 {
    110 	/*
    111 	 * ffs_init() ensures to initialize necessary resources
    112 	 * only once.
    113 	 */
    114 	ffs_init();
    115 }
    116 
    117 void
    118 mfs_done()
    119 {
    120 	/*
    121 	 * ffs_done() ensures to free necessary resources
    122 	 * only once, when it's no more needed.
    123 	 */
    124 	ffs_done();
    125 }
    126 
    127 /*
    128  * Called by main() when mfs is going to be mounted as root.
    129  */
    130 
    131 int
    132 mfs_mountroot()
    133 {
    134 	struct fs *fs;
    135 	struct mount *mp;
    136 	struct proc *p = curproc;	/* XXX */
    137 	struct ufsmount *ump;
    138 	struct mfsnode *mfsp;
    139 	int error = 0;
    140 
    141 	/*
    142 	 * Get vnodes for rootdev.
    143 	 */
    144 	if (bdevvp(rootdev, &rootvp)) {
    145 		printf("mfs_mountroot: can't setup bdevvp's");
    146 		return (error);
    147 	}
    148 
    149 	if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) {
    150 		vrele(rootvp);
    151 		return (error);
    152 	}
    153 
    154 	mfsp = malloc(sizeof *mfsp, M_MFSNODE, M_WAITOK);
    155 	rootvp->v_data = mfsp;
    156 	rootvp->v_op = mfs_vnodeop_p;
    157 	rootvp->v_tag = VT_MFS;
    158 	mfsp->mfs_baseoff = mfs_rootbase;
    159 	mfsp->mfs_size = mfs_rootsize;
    160 	mfsp->mfs_vnode = rootvp;
    161 	mfsp->mfs_proc = NULL;		/* indicate kernel space */
    162 	BUFQ_INIT(&mfsp->mfs_buflist);
    163 	if ((error = ffs_mountfs(rootvp, mp, p)) != 0) {
    164 		mp->mnt_op->vfs_refcount--;
    165 		vfs_unbusy(mp);
    166 		free(mp, M_MOUNT);
    167 		free(mfsp, M_MFSNODE);
    168 		vrele(rootvp);
    169 		return (error);
    170 	}
    171 	simple_lock(&mountlist_slock);
    172 	CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
    173 	simple_unlock(&mountlist_slock);
    174 	mp->mnt_vnodecovered = NULLVP;
    175 	ump = VFSTOUFS(mp);
    176 	fs = ump->um_fs;
    177 	(void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0);
    178 	(void)ffs_statfs(mp, &mp->mnt_stat, p);
    179 	vfs_unbusy(mp);
    180 	inittodr((time_t)0);
    181 	return (0);
    182 }
    183 
    184 /*
    185  * This is called early in boot to set the base address and size
    186  * of the mini-root.
    187  */
    188 int
    189 mfs_initminiroot(base)
    190 	caddr_t base;
    191 {
    192 	struct fs *fs = (struct fs *)(base + SBOFF);
    193 	extern int (*mountroot) __P((void));
    194 
    195 	/* check for valid super block */
    196 	if (fs->fs_magic != FS_MAGIC || fs->fs_bsize > MAXBSIZE ||
    197 	    fs->fs_bsize < sizeof(struct fs))
    198 		return (0);
    199 	mountroot = mfs_mountroot;
    200 	mfs_rootbase = base;
    201 	mfs_rootsize = fs->fs_fsize * fs->fs_size;
    202 	rootdev = makedev(255, mfs_minor);
    203 	mfs_minor++;
    204 	return (mfs_rootsize);
    205 }
    206 
    207 /*
    208  * VFS Operations.
    209  *
    210  * mount system call
    211  */
    212 /* ARGSUSED */
    213 int
    214 mfs_mount(mp, path, data, ndp, p)
    215 	struct mount *mp;
    216 	const char *path;
    217 	void *data;
    218 	struct nameidata *ndp;
    219 	struct proc *p;
    220 {
    221 	struct vnode *devvp;
    222 	struct mfs_args args;
    223 	struct ufsmount *ump;
    224 	struct fs *fs;
    225 	struct mfsnode *mfsp;
    226 	size_t size;
    227 	int flags, error;
    228 
    229 	error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args));
    230 	if (error)
    231 		return (error);
    232 
    233 	/*
    234 	 * If updating, check whether changing from read-only to
    235 	 * read/write; if there is no device name, that's all we do.
    236 	 */
    237 	if (mp->mnt_flag & MNT_UPDATE) {
    238 		ump = VFSTOUFS(mp);
    239 		fs = ump->um_fs;
    240 		if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
    241 			flags = WRITECLOSE;
    242 			if (mp->mnt_flag & MNT_FORCE)
    243 				flags |= FORCECLOSE;
    244 			error = ffs_flushfiles(mp, flags, p);
    245 			if (error)
    246 				return (error);
    247 		}
    248 		if (fs->fs_ronly && (mp->mnt_flag & MNT_WANTRDWR))
    249 			fs->fs_ronly = 0;
    250 		if (args.fspec == 0)
    251 			return (vfs_export(mp, &ump->um_export, &args.export));
    252 		return (0);
    253 	}
    254 	error = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp);
    255 	if (error)
    256 		return (error);
    257 	devvp->v_type = VBLK;
    258 	if (checkalias(devvp, makedev(255, mfs_minor), (struct mount *)0))
    259 		panic("mfs_mount: dup dev");
    260 	mfs_minor++;
    261 	mfsp = (struct mfsnode *)malloc(sizeof *mfsp, M_MFSNODE, M_WAITOK);
    262 	devvp->v_data = mfsp;
    263 	mfsp->mfs_baseoff = args.base;
    264 	mfsp->mfs_size = args.size;
    265 	mfsp->mfs_vnode = devvp;
    266 	mfsp->mfs_proc = p;
    267 	BUFQ_INIT(&mfsp->mfs_buflist);
    268 	if ((error = ffs_mountfs(devvp, mp, p)) != 0) {
    269 		BUFQ_FIRST(&mfsp->mfs_buflist) = (struct buf *) -1;
    270 		vrele(devvp);
    271 		return (error);
    272 	}
    273 	ump = VFSTOUFS(mp);
    274 	fs = ump->um_fs;
    275 	(void) copyinstr(path, fs->fs_fsmnt, sizeof(fs->fs_fsmnt) - 1, &size);
    276 	memset(fs->fs_fsmnt + size, 0, sizeof(fs->fs_fsmnt) - size);
    277 	memcpy(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN);
    278 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
    279 	    &size);
    280 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
    281 	return (0);
    282 }
    283 
    284 int	mfs_pri = PWAIT | PCATCH;		/* XXX prob. temp */
    285 
    286 /*
    287  * Used to grab the process and keep it in the kernel to service
    288  * memory filesystem I/O requests.
    289  *
    290  * Loop servicing I/O requests.
    291  * Copy the requested data into or out of the memory filesystem
    292  * address space.
    293  */
    294 /* ARGSUSED */
    295 int
    296 mfs_start(mp, flags, p)
    297 	struct mount *mp;
    298 	int flags;
    299 	struct proc *p;
    300 {
    301 	struct vnode *vp = VFSTOUFS(mp)->um_devvp;
    302 	struct mfsnode *mfsp = VTOMFS(vp);
    303 	struct buf *bp;
    304 	caddr_t base;
    305 	int sleepreturn = 0;
    306 
    307 	base = mfsp->mfs_baseoff;
    308 	while (BUFQ_FIRST(&mfsp->mfs_buflist) != (struct buf *) -1) {
    309 		while ((bp = BUFQ_FIRST(&mfsp->mfs_buflist)) != NULL) {
    310 			BUFQ_REMOVE(&mfsp->mfs_buflist, bp);
    311 			mfs_doio(bp, base);
    312 			wakeup((caddr_t)bp);
    313 		}
    314 		/*
    315 		 * If a non-ignored signal is received, try to unmount.
    316 		 * If that fails, or the filesystem is already in the
    317 		 * process of being unmounted, clear the signal (it has been
    318 		 * "processed"), otherwise we will loop here, as tsleep
    319 		 * will always return EINTR/ERESTART.
    320 		 */
    321 		if (sleepreturn != 0) {
    322 			/*
    323 			 * XXX Freeze syncer.  Must do this before locking
    324 			 * the mount point.  See dounmount() for details.
    325 			 */
    326 			lockmgr(&syncer_lock, LK_EXCLUSIVE, NULL);
    327 			if (vfs_busy(mp, LK_NOWAIT, 0) != 0)
    328 				lockmgr(&syncer_lock, LK_RELEASE, NULL);
    329 			else if (dounmount(mp, 0, p) != 0)
    330 				CLRSIG(p, CURSIG(p));
    331 			sleepreturn = 0;
    332 			continue;
    333 		}
    334 
    335 		sleepreturn = tsleep(vp, mfs_pri, "mfsidl", 0);
    336 	}
    337 	return (sleepreturn);
    338 }
    339 
    340 /*
    341  * Get file system statistics.
    342  */
    343 int
    344 mfs_statfs(mp, sbp, p)
    345 	struct mount *mp;
    346 	struct statfs *sbp;
    347 	struct proc *p;
    348 {
    349 	int error;
    350 
    351 	error = ffs_statfs(mp, sbp, p);
    352 #ifdef COMPAT_09
    353 	sbp->f_type = 3;
    354 #else
    355 	sbp->f_type = 0;
    356 #endif
    357 	strncpy(&sbp->f_fstypename[0], mp->mnt_op->vfs_name, MFSNAMELEN);
    358 	return (error);
    359 }
    360