mfs_vfsops.c revision 1.72 
1/*	$NetBSD: mfs_vfsops.c,v 1.72 2006/04/15 01:16:40 christos 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. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	@(#)mfs_vfsops.c	8.11 (Berkeley) 6/19/95
32 */
33
34#include <sys/cdefs.h>
35__KERNEL_RCSID(0, "$NetBSD: mfs_vfsops.c,v 1.72 2006/04/15 01:16:40 christos Exp $");
36
37#if defined(_KERNEL_OPT)
38#include "opt_compat_netbsd.h"
39#endif
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/sysctl.h>
44#include <sys/time.h>
45#include <sys/kernel.h>
46#include <sys/proc.h>
47#include <sys/buf.h>
48#include <sys/bufq.h>
49#include <sys/mount.h>
50#include <sys/signalvar.h>
51#include <sys/vnode.h>
52#include <sys/malloc.h>
53
54#include <miscfs/syncfs/syncfs.h>
55
56#include <ufs/ufs/quota.h>
57#include <ufs/ufs/inode.h>
58#include <ufs/ufs/ufsmount.h>
59#include <ufs/ufs/ufs_extern.h>
60
61#include <ufs/ffs/fs.h>
62#include <ufs/ffs/ffs_extern.h>
63
64#include <ufs/mfs/mfsnode.h>
65#include <ufs/mfs/mfs_extern.h>
66
67caddr_t	mfs_rootbase;	/* address of mini-root in kernel virtual memory */
68u_long	mfs_rootsize;	/* size of mini-root in bytes */
69
70static	int mfs_minor;	/* used for building internal dev_t */
71
72extern int (**mfs_vnodeop_p)(void *);
73
74MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part");
75
76/*
77 * mfs vfs operations.
78 */
79
80extern const struct vnodeopv_desc mfs_vnodeop_opv_desc;
81
82const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = {
83	&mfs_vnodeop_opv_desc,
84	NULL,
85};
86
87struct vfsops mfs_vfsops = {
88	MOUNT_MFS,
89	mfs_mount,
90	mfs_start,
91	ffs_unmount,
92	ufs_root,
93	ufs_quotactl,
94	mfs_statvfs,
95	ffs_sync,
96	ffs_vget,
97	ffs_fhtovp,
98	ffs_vptofh,
99	mfs_init,
100	mfs_reinit,
101	mfs_done,
102	NULL,
103	(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
104	vfs_stdextattrctl,
105	mfs_vnodeopv_descs,
106};
107VFS_ATTACH(mfs_vfsops);
108
109SYSCTL_SETUP(sysctl_vfs_mfs_setup, "sysctl vfs.mfs subtree setup")
110{
111
112	sysctl_createv(clog, 0, NULL, NULL,
113		       CTLFLAG_PERMANENT,
114		       CTLTYPE_NODE, "vfs", NULL,
115		       NULL, 0, NULL, 0,
116		       CTL_VFS, CTL_EOL);
117	sysctl_createv(clog, 0, NULL, NULL,
118		       CTLFLAG_PERMANENT|CTLFLAG_ALIAS,
119		       CTLTYPE_NODE, "mfs",
120		       SYSCTL_DESCR("Memory based file system"),
121		       NULL, 1, NULL, 0,
122		       CTL_VFS, 3, CTL_EOL);
123	/*
124	 * XXX the "1" and the "3" above could be dynamic, thereby
125	 * eliminating one more instance of the "number to vfs"
126	 * mapping problem, but they are in order as taken from
127	 * sys/mount.h
128	 */
129}
130
131/*
132 * Memory based filesystem initialization.
133 */
134void
135mfs_init(void)
136{
137#ifdef _LKM
138	malloc_type_attach(M_MFSNODE);
139#endif
140	/*
141	 * ffs_init() ensures to initialize necessary resources
142	 * only once.
143	 */
144	ffs_init();
145}
146
147void
148mfs_reinit(void)
149{
150	ffs_reinit();
151}
152
153void
154mfs_done(void)
155{
156	/*
157	 * ffs_done() ensures to free necessary resources
158	 * only once, when it's no more needed.
159	 */
160	ffs_done();
161#ifdef _LKM
162	malloc_type_detach(M_MFSNODE);
163#endif
164}
165
166/*
167 * Called by main() when mfs is going to be mounted as root.
168 */
169
170int
171mfs_mountroot(void)
172{
173	struct fs *fs;
174	struct mount *mp;
175	struct lwp *l = curlwp;		/* XXX */
176	struct ufsmount *ump;
177	struct mfsnode *mfsp;
178	int error = 0;
179
180	if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) {
181		vrele(rootvp);
182		return (error);
183	}
184
185	mfsp = malloc(sizeof *mfsp, M_MFSNODE, M_WAITOK);
186	rootvp->v_data = mfsp;
187	rootvp->v_op = mfs_vnodeop_p;
188	rootvp->v_tag = VT_MFS;
189	mfsp->mfs_baseoff = mfs_rootbase;
190	mfsp->mfs_size = mfs_rootsize;
191	mfsp->mfs_vnode = rootvp;
192	mfsp->mfs_proc = NULL;		/* indicate kernel space */
193	mfsp->mfs_shutdown = 0;
194	bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0);
195	if ((error = ffs_mountfs(rootvp, mp, l)) != 0) {
196		mp->mnt_op->vfs_refcount--;
197		vfs_unbusy(mp);
198		bufq_free(mfsp->mfs_buflist);
199		free(mp, M_MOUNT);
200		free(mfsp, M_MFSNODE);
201		return (error);
202	}
203	simple_lock(&mountlist_slock);
204	CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
205	simple_unlock(&mountlist_slock);
206	mp->mnt_vnodecovered = NULLVP;
207	ump = VFSTOUFS(mp);
208	fs = ump->um_fs;
209	(void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0);
210	(void)ffs_statvfs(mp, &mp->mnt_stat, l);
211	vfs_unbusy(mp);
212	return (0);
213}
214
215/*
216 * This is called early in boot to set the base address and size
217 * of the mini-root.
218 */
219int
220mfs_initminiroot(caddr_t base)
221{
222	struct fs *fs = (struct fs *)(base + SBLOCK_UFS1);
223
224	/* check for valid super block */
225	if (fs->fs_magic != FS_UFS1_MAGIC || fs->fs_bsize > MAXBSIZE ||
226	    fs->fs_bsize < sizeof(struct fs))
227		return (0);
228	mountroot = mfs_mountroot;
229	mfs_rootbase = base;
230	mfs_rootsize = fs->fs_fsize * fs->fs_size;
231	rootdev = makedev(255, mfs_minor);
232	mfs_minor++;
233	return (mfs_rootsize);
234}
235
236/*
237 * VFS Operations.
238 *
239 * mount system call
240 */
241/* ARGSUSED */
242int
243mfs_mount(struct mount *mp, const char *path, void *data,
244	struct nameidata *ndp, struct lwp *l)
245{
246	struct vnode *devvp;
247	struct mfs_args args;
248	struct ufsmount *ump;
249	struct fs *fs;
250	struct mfsnode *mfsp;
251	struct proc *p;
252	int flags, error;
253
254	p = l->l_proc;
255	if (mp->mnt_flag & MNT_GETARGS) {
256		struct vnode *vp;
257
258		ump = VFSTOUFS(mp);
259		if (ump == NULL)
260			return EIO;
261
262		vp = ump->um_devvp;
263		if (vp == NULL)
264			return EIO;
265
266		mfsp = VTOMFS(vp);
267		if (mfsp == NULL)
268			return EIO;
269
270		args.fspec = NULL;
271		args.base = mfsp->mfs_baseoff;
272		args.size = mfsp->mfs_size;
273		return copyout(&args, data, sizeof(args));
274	}
275	/*
276	 * XXX turn off async to avoid hangs when writing lots of data.
277	 * the problem is that MFS needs to allocate pages to clean pages,
278	 * so if we wait until the last minute to clean pages then there
279	 * may not be any pages available to do the cleaning.
280	 * ... and since the default partially-synchronous mode turns out
281	 * to not be sufficient under heavy load, make it full synchronous.
282	 */
283	mp->mnt_flag &= ~MNT_ASYNC;
284	mp->mnt_flag |= MNT_SYNCHRONOUS;
285
286	error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args));
287	if (error)
288		return (error);
289
290	/*
291	 * If updating, check whether changing from read-only to
292	 * read/write; if there is no device name, that's all we do.
293	 */
294	if (mp->mnt_flag & MNT_UPDATE) {
295		ump = VFSTOUFS(mp);
296		fs = ump->um_fs;
297		if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
298			flags = WRITECLOSE;
299			if (mp->mnt_flag & MNT_FORCE)
300				flags |= FORCECLOSE;
301			error = ffs_flushfiles(mp, flags, l);
302			if (error)
303				return (error);
304		}
305		if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR))
306			fs->fs_ronly = 0;
307		if (args.fspec == NULL)
308			return EINVAL;
309		return (0);
310	}
311	error = getnewvnode(VT_MFS, (struct mount *)0, mfs_vnodeop_p, &devvp);
312	if (error)
313		return (error);
314	devvp->v_type = VBLK;
315	if (checkalias(devvp, makedev(255, mfs_minor), (struct mount *)0))
316		panic("mfs_mount: dup dev");
317	mfs_minor++;
318	mfsp = (struct mfsnode *)malloc(sizeof *mfsp, M_MFSNODE, M_WAITOK);
319	devvp->v_data = mfsp;
320	mfsp->mfs_baseoff = args.base;
321	mfsp->mfs_size = args.size;
322	mfsp->mfs_vnode = devvp;
323	mfsp->mfs_proc = p;
324	mfsp->mfs_shutdown = 0;
325	bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0);
326	if ((error = ffs_mountfs(devvp, mp, l)) != 0) {
327		mfsp->mfs_shutdown = 1;
328		vrele(devvp);
329		return (error);
330	}
331	ump = VFSTOUFS(mp);
332	fs = ump->um_fs;
333	error = set_statvfs_info(path, UIO_USERSPACE, args.fspec,
334	    UIO_USERSPACE, mp, l);
335	if (error)
336		return error;
337	(void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname,
338		sizeof(fs->fs_fsmnt));
339	fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0';
340	/* XXX: cleanup on error */
341	return 0;
342}
343
344int	mfs_pri = PWAIT | PCATCH;		/* XXX prob. temp */
345
346/*
347 * Used to grab the process and keep it in the kernel to service
348 * memory filesystem I/O requests.
349 *
350 * Loop servicing I/O requests.
351 * Copy the requested data into or out of the memory filesystem
352 * address space.
353 */
354/* ARGSUSED */
355int
356mfs_start(struct mount *mp, int flags, struct lwp *l)
357{
358	struct vnode *vp = VFSTOUFS(mp)->um_devvp;
359	struct mfsnode *mfsp = VTOMFS(vp);
360	struct buf *bp;
361	caddr_t base;
362	int sleepreturn = 0;
363
364	base = mfsp->mfs_baseoff;
365	while (mfsp->mfs_shutdown != 1) {
366		while ((bp = BUFQ_GET(mfsp->mfs_buflist)) != NULL) {
367			mfs_doio(bp, base);
368			wakeup((caddr_t)bp);
369		}
370		/*
371		 * If a non-ignored signal is received, try to unmount.
372		 * If that fails, or the filesystem is already in the
373		 * process of being unmounted, clear the signal (it has been
374		 * "processed"), otherwise we will loop here, as tsleep
375		 * will always return EINTR/ERESTART.
376		 */
377		if (sleepreturn != 0) {
378			/*
379			 * XXX Freeze syncer.  Must do this before locking
380			 * the mount point.  See dounmount() for details.
381			 */
382			lockmgr(&syncer_lock, LK_EXCLUSIVE, NULL);
383			if (vfs_busy(mp, LK_NOWAIT, 0) != 0)
384				lockmgr(&syncer_lock, LK_RELEASE, NULL);
385			else if (dounmount(mp, 0, l) != 0)
386				CLRSIG(l);
387			sleepreturn = 0;
388			continue;
389		}
390
391		sleepreturn = tsleep(vp, mfs_pri, "mfsidl", 0);
392	}
393	KASSERT(BUFQ_PEEK(mfsp->mfs_buflist) == NULL);
394	bufq_free(mfsp->mfs_buflist);
395	return (sleepreturn);
396}
397
398/*
399 * Get file system statistics.
400 */
401int
402mfs_statvfs(struct mount *mp, struct statvfs *sbp, struct lwp *l)
403{
404	int error;
405
406	error = ffs_statvfs(mp, sbp, l);
407	if (error)
408		return error;
409	(void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name,
410	    sizeof(sbp->f_fstypename));
411	sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0';
412	return 0;
413}
414