1 /* $NetBSD: mfs_vfsops.c,v 1.110 2015/03/17 09:39:29 hannken 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 1.110 2015/03/17 09:39:29 hannken 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/kmem.h>
53 #include <sys/module.h>
54
55 #include <miscfs/genfs/genfs.h>
56 #include <miscfs/specfs/specdev.h>
57
58 #include <ufs/ufs/quota.h>
59 #include <ufs/ufs/inode.h>
60 #include <ufs/ufs/ufsmount.h>
61 #include <ufs/ufs/ufs_extern.h>
62
63 #include <ufs/ffs/fs.h>
64 #include <ufs/ffs/ffs_extern.h>
65
66 #include <ufs/mfs/mfsnode.h>
67 #include <ufs/mfs/mfs_extern.h>
68
69 MODULE(MODULE_CLASS_VFS, mfs, "ffs");
70
71 kmutex_t mfs_lock; /* global lock */
72
73 /* used for building internal dev_t, minor == 0 reserved for miniroot */
74 static devminor_t mfs_minor = 1;
75 static int mfs_initcnt;
76
77 extern int (**mfs_vnodeop_p)(void *);
78
79 static struct sysctllog *mfs_sysctl_log;
80
81 /*
82 * mfs vfs operations.
83 */
84
85 extern const struct vnodeopv_desc mfs_vnodeop_opv_desc;
86
87 const struct vnodeopv_desc * const mfs_vnodeopv_descs[] = {
88 &mfs_vnodeop_opv_desc,
89 NULL,
90 };
91
92 struct vfsops mfs_vfsops = {
93 .vfs_name = MOUNT_MFS,
94 .vfs_min_mount_data = sizeof (struct mfs_args),
95 .vfs_mount = mfs_mount,
96 .vfs_start = mfs_start,
97 .vfs_unmount = ffs_unmount,
98 .vfs_root = ufs_root,
99 .vfs_quotactl = ufs_quotactl,
100 .vfs_statvfs = mfs_statvfs,
101 .vfs_sync = ffs_sync,
102 .vfs_vget = ufs_vget,
103 .vfs_loadvnode = ffs_loadvnode,
104 .vfs_newvnode = ffs_newvnode,
105 .vfs_fhtovp = ffs_fhtovp,
106 .vfs_vptofh = ffs_vptofh,
107 .vfs_init = mfs_init,
108 .vfs_reinit = mfs_reinit,
109 .vfs_done = mfs_done,
110 .vfs_snapshot = (void *)eopnotsupp,
111 .vfs_extattrctl = vfs_stdextattrctl,
112 .vfs_suspendctl = (void *)eopnotsupp,
113 .vfs_renamelock_enter = genfs_renamelock_enter,
114 .vfs_renamelock_exit = genfs_renamelock_exit,
115 .vfs_fsync = (void *)eopnotsupp,
116 .vfs_opv_descs = mfs_vnodeopv_descs
117 };
118
119 static int
mfs_modcmd(modcmd_t cmd,void * arg)120 mfs_modcmd(modcmd_t cmd, void *arg)
121 {
122 int error;
123
124 switch (cmd) {
125 case MODULE_CMD_INIT:
126 error = vfs_attach(&mfs_vfsops);
127 if (error != 0)
128 break;
129 sysctl_createv(&mfs_sysctl_log, 0, NULL, NULL,
130 CTLFLAG_PERMANENT|CTLFLAG_ALIAS,
131 CTLTYPE_NODE, "mfs",
132 SYSCTL_DESCR("Memory based file system"),
133 NULL, 1, NULL, 0,
134 CTL_VFS, 3, CTL_EOL);
135 /*
136 * XXX the "1" and the "3" above could be dynamic, thereby
137 * eliminating one more instance of the "number to vfs"
138 * mapping problem, but they are in order as taken from
139 * sys/mount.h
140 */
141 break;
142 case MODULE_CMD_FINI:
143 error = vfs_detach(&mfs_vfsops);
144 if (error != 0)
145 break;
146 sysctl_teardown(&mfs_sysctl_log);
147 break;
148 default:
149 error = ENOTTY;
150 break;
151 }
152
153 return (error);
154 }
155
156 /*
157 * Memory based filesystem initialization.
158 */
159 void
mfs_init(void)160 mfs_init(void)
161 {
162
163 if (mfs_initcnt++ == 0) {
164 mutex_init(&mfs_lock, MUTEX_DEFAULT, IPL_NONE);
165 ffs_init();
166 }
167 }
168
169 void
mfs_reinit(void)170 mfs_reinit(void)
171 {
172
173 ffs_reinit();
174 }
175
176 void
mfs_done(void)177 mfs_done(void)
178 {
179
180 if (--mfs_initcnt == 0) {
181 ffs_done();
182 mutex_destroy(&mfs_lock);
183 }
184 }
185
186 /*
187 * Called by main() when mfs is going to be mounted as root.
188 */
189
190 int
mfs_mountroot(void)191 mfs_mountroot(void)
192 {
193 struct fs *fs;
194 struct mount *mp;
195 struct lwp *l = curlwp; /* XXX */
196 struct ufsmount *ump;
197 struct mfsnode *mfsp;
198 int error = 0;
199
200 if ((error = vfs_rootmountalloc(MOUNT_MFS, "mfs_root", &mp))) {
201 vrele(rootvp);
202 return (error);
203 }
204
205 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP);
206 rootvp->v_data = mfsp;
207 rootvp->v_op = mfs_vnodeop_p;
208 rootvp->v_tag = VT_MFS;
209 mfsp->mfs_baseoff = mfs_rootbase;
210 mfsp->mfs_size = mfs_rootsize;
211 mfsp->mfs_vnode = rootvp;
212 mfsp->mfs_proc = NULL; /* indicate kernel space */
213 mfsp->mfs_shutdown = 0;
214 cv_init(&mfsp->mfs_cv, "mfs");
215 mfsp->mfs_refcnt = 1;
216 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0);
217 if ((error = ffs_mountfs(rootvp, mp, l)) != 0) {
218 vfs_unbusy(mp, false, NULL);
219 bufq_free(mfsp->mfs_buflist);
220 vfs_destroy(mp);
221 kmem_free(mfsp, sizeof(*mfsp));
222 return (error);
223 }
224 mountlist_append(mp);
225 mp->mnt_vnodecovered = NULLVP;
226 ump = VFSTOUFS(mp);
227 fs = ump->um_fs;
228 (void) copystr(mp->mnt_stat.f_mntonname, fs->fs_fsmnt, MNAMELEN - 1, 0);
229 (void)ffs_statvfs(mp, &mp->mnt_stat);
230 vfs_unbusy(mp, false, NULL);
231 return (0);
232 }
233
234 /*
235 * VFS Operations.
236 *
237 * mount system call
238 */
239 /* ARGSUSED */
240 int
mfs_mount(struct mount * mp,const char * path,void * data,size_t * data_len)241 mfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
242 {
243 struct lwp *l = curlwp;
244 struct vnode *devvp;
245 struct mfs_args *args = data;
246 struct ufsmount *ump;
247 struct fs *fs;
248 struct mfsnode *mfsp;
249 struct proc *p;
250 devminor_t minor;
251 int flags, error = 0;
252
253 if (args == NULL)
254 return EINVAL;
255 if (*data_len < sizeof *args)
256 return EINVAL;
257
258 p = l->l_proc;
259 if (mp->mnt_flag & MNT_GETARGS) {
260 struct vnode *vp;
261
262 ump = VFSTOUFS(mp);
263 if (ump == NULL)
264 return EIO;
265
266 vp = ump->um_devvp;
267 if (vp == NULL)
268 return EIO;
269
270 mfsp = VTOMFS(vp);
271 if (mfsp == NULL)
272 return EIO;
273
274 args->fspec = NULL;
275 args->base = mfsp->mfs_baseoff;
276 args->size = mfsp->mfs_size;
277 *data_len = sizeof *args;
278 return 0;
279 }
280 /*
281 * XXX turn off async to avoid hangs when writing lots of data.
282 * the problem is that MFS needs to allocate pages to clean pages,
283 * so if we wait until the last minute to clean pages then there
284 * may not be any pages available to do the cleaning.
285 * ... and since the default partially-synchronous mode turns out
286 * to not be sufficient under heavy load, make it full synchronous.
287 */
288 mp->mnt_flag &= ~MNT_ASYNC;
289 mp->mnt_flag |= MNT_SYNCHRONOUS;
290
291 /*
292 * If updating, check whether changing from read-only to
293 * read/write; if there is no device name, that's all we do.
294 */
295 if (mp->mnt_flag & MNT_UPDATE) {
296 ump = VFSTOUFS(mp);
297 fs = ump->um_fs;
298 if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
299 flags = WRITECLOSE;
300 if (mp->mnt_flag & MNT_FORCE)
301 flags |= FORCECLOSE;
302 error = ffs_flushfiles(mp, flags, l);
303 if (error)
304 return (error);
305 }
306 if (fs->fs_ronly && (mp->mnt_iflag & IMNT_WANTRDWR))
307 fs->fs_ronly = 0;
308 if (args->fspec == NULL)
309 return EINVAL;
310 return (0);
311 }
312 mutex_enter(&mfs_lock);
313 minor = mfs_minor++;
314 mutex_exit(&mfs_lock);
315 error = bdevvp(makedev(255, minor), &devvp);
316 if (error)
317 return (error);
318 mfsp = kmem_alloc(sizeof(*mfsp), KM_SLEEP);
319 /*
320 * Changing v_op and v_data here is safe as we are
321 * the exclusive owner of this device node.
322 */
323 KASSERT(devvp->v_op == spec_vnodeop_p);
324 KASSERT(devvp->v_data == NULL);
325 devvp->v_op = mfs_vnodeop_p;
326 devvp->v_data = mfsp;
327 mfsp->mfs_baseoff = args->base;
328 mfsp->mfs_size = args->size;
329 mfsp->mfs_vnode = devvp;
330 mfsp->mfs_proc = p;
331 mfsp->mfs_shutdown = 0;
332 cv_init(&mfsp->mfs_cv, "mfsidl");
333 mfsp->mfs_refcnt = 1;
334 bufq_alloc(&mfsp->mfs_buflist, "fcfs", 0);
335 if ((error = ffs_mountfs(devvp, mp, l)) != 0) {
336 mfsp->mfs_shutdown = 1;
337 vrele(devvp);
338 return (error);
339 }
340 ump = VFSTOUFS(mp);
341 fs = ump->um_fs;
342 error = set_statvfs_info(path, UIO_USERSPACE, args->fspec,
343 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
344 if (error)
345 return error;
346 (void)strncpy(fs->fs_fsmnt, mp->mnt_stat.f_mntonname,
347 sizeof(fs->fs_fsmnt));
348 fs->fs_fsmnt[sizeof(fs->fs_fsmnt) - 1] = '\0';
349 /* XXX: cleanup on error */
350 return 0;
351 }
352
353 /*
354 * Used to grab the process and keep it in the kernel to service
355 * memory filesystem I/O requests.
356 *
357 * Loop servicing I/O requests.
358 * Copy the requested data into or out of the memory filesystem
359 * address space.
360 */
361 /* ARGSUSED */
362 int
mfs_start(struct mount * mp,int flags)363 mfs_start(struct mount *mp, int flags)
364 {
365 struct vnode *vp;
366 struct mfsnode *mfsp;
367 struct proc *p;
368 struct buf *bp;
369 void *base;
370 int sleepreturn = 0, refcnt, error;
371 ksiginfoq_t kq;
372
373 /*
374 * Ensure that file system is still mounted when getting mfsnode.
375 * Add a reference to the mfsnode to prevent it disappearing in
376 * this routine.
377 */
378 if ((error = vfs_busy(mp, NULL)) != 0)
379 return error;
380 vp = VFSTOUFS(mp)->um_devvp;
381 mfsp = VTOMFS(vp);
382 mutex_enter(&mfs_lock);
383 mfsp->mfs_refcnt++;
384 mutex_exit(&mfs_lock);
385 vfs_unbusy(mp, false, NULL);
386
387 base = mfsp->mfs_baseoff;
388 mutex_enter(&mfs_lock);
389 while (mfsp->mfs_shutdown != 1) {
390 while ((bp = bufq_get(mfsp->mfs_buflist)) != NULL) {
391 mutex_exit(&mfs_lock);
392 mfs_doio(bp, base);
393 mutex_enter(&mfs_lock);
394 }
395 /*
396 * If a non-ignored signal is received, try to unmount.
397 * If that fails, or the filesystem is already in the
398 * process of being unmounted, clear the signal (it has been
399 * "processed"), otherwise we will loop here, as tsleep
400 * will always return EINTR/ERESTART.
401 */
402 if (sleepreturn != 0) {
403 mutex_exit(&mfs_lock);
404 if (dounmount(mp, 0, curlwp) != 0) {
405 p = curproc;
406 ksiginfo_queue_init(&kq);
407 mutex_enter(p->p_lock);
408 sigclearall(p, NULL, &kq);
409 mutex_exit(p->p_lock);
410 ksiginfo_queue_drain(&kq);
411 }
412 sleepreturn = 0;
413 mutex_enter(&mfs_lock);
414 continue;
415 }
416
417 sleepreturn = cv_wait_sig(&mfsp->mfs_cv, &mfs_lock);
418 }
419 KASSERT(bufq_peek(mfsp->mfs_buflist) == NULL);
420 refcnt = --mfsp->mfs_refcnt;
421 mutex_exit(&mfs_lock);
422 if (refcnt == 0) {
423 bufq_free(mfsp->mfs_buflist);
424 cv_destroy(&mfsp->mfs_cv);
425 kmem_free(mfsp, sizeof(*mfsp));
426 }
427 return (sleepreturn);
428 }
429
430 /*
431 * Get file system statistics.
432 */
433 int
mfs_statvfs(struct mount * mp,struct statvfs * sbp)434 mfs_statvfs(struct mount *mp, struct statvfs *sbp)
435 {
436 int error;
437
438 error = ffs_statvfs(mp, sbp);
439 if (error)
440 return error;
441 (void)strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name,
442 sizeof(sbp->f_fstypename));
443 sbp->f_fstypename[sizeof(sbp->f_fstypename) - 1] = '\0';
444 return 0;
445 }
446