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 |
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 |
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 |
170 | mfs_reinit(void) |
171 | { |
172 | |
173 | ffs_reinit(); |
174 | } |
175 | |
176 | 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 |
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 |
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 |
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 |
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 | |