xref: /netbsd-src/sys/fs/tmpfs/tmpfs_vfsops.c (revision 5b84b3983f71fd20a534cfa5d1556623a8aaa717)
1 /*	$NetBSD: tmpfs_vfsops.c,v 1.2 2005/09/10 22:28:57 jmmv Exp $	*/
2 
3 /*
4  * Copyright (c) 2005 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Julio M. Merino Vidal.
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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Efficient memory file system.
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: tmpfs_vfsops.c,v 1.2 2005/09/10 22:28:57 jmmv Exp $");
45 
46 #include <sys/param.h>
47 #include <sys/types.h>
48 #include <sys/malloc.h>
49 #include <sys/mount.h>
50 #include <sys/systm.h>
51 #include <sys/vnode.h>
52 
53 #include <fs/tmpfs/tmpfs.h>
54 
55 MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures");
56 
57 /* --------------------------------------------------------------------- */
58 
59 static int	tmpfs_mount(struct mount *, const char *, void *,
60 		    struct nameidata *, struct proc *);
61 static int	tmpfs_start(struct mount *, int, struct proc *);
62 static int	tmpfs_unmount(struct mount *, int, struct proc *);
63 static int	tmpfs_root(struct mount *, struct vnode **);
64 static int	tmpfs_quotactl(struct mount *, int, uid_t, void *,
65 		    struct proc *);
66 static int	tmpfs_vget(struct mount *, ino_t, struct vnode **);
67 static int	tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **);
68 static int	tmpfs_vptofh(struct vnode *, struct fid *);
69 static int	tmpfs_statvfs(struct mount *, struct statvfs *, struct proc *);
70 static int	tmpfs_sync(struct mount *, int, struct ucred *, struct proc *);
71 static void	tmpfs_init(void);
72 static void	tmpfs_done(void);
73 static int	tmpfs_checkexp(struct mount *, struct mbuf *, int *,
74 		    struct ucred **);
75 static int	tmpfs_snapshot(struct mount *, struct vnode *,
76 		    struct timespec *);
77 
78 /* --------------------------------------------------------------------- */
79 
80 static int
81 tmpfs_mount(struct mount *mp, const char *path, void *data,
82     struct nameidata *ndp, struct proc *p)
83 {
84 	int error;
85 	ino_t nodes;
86 	size_t pages;
87 	struct tmpfs_mount *tmp;
88 	struct tmpfs_node *root;
89 	struct tmpfs_args args;
90 
91 	/* Handle retrieval of mount point arguments. */
92 	if (mp->mnt_flag & MNT_GETARGS) {
93 		if (mp->mnt_data == NULL)
94 			return EIO;
95 		tmp = VFS_TO_TMPFS(mp);
96 
97 		args.ta_version = TMPFS_ARGS_VERSION;
98 		args.ta_fspec = NULL;
99 		args.ta_nodes_max = tmp->tm_nodes_max;
100 		args.ta_size_max = tmp->tm_pages_max * PAGE_SIZE;
101 
102 		root = tmp->tm_root;
103 		args.ta_root_uid = root->tn_uid;
104 		args.ta_root_gid = root->tn_gid;
105 		args.ta_root_mode = root->tn_mode;
106 
107 		vfs_showexport(mp, &args, &tmp->tm_export);
108 
109 		return copyout(&args, data, sizeof(args));
110 	}
111 
112 	/* Verify that we have parameters, as they are required. */
113 	if (data == NULL)
114 		return EINVAL;
115 
116 	/* Get the mount parameters. */
117 	error = copyin(data, &args, sizeof(args));
118 	if (error != 0)
119 		return error;
120 
121 	if (mp->mnt_flag & MNT_UPDATE) {
122 		if (mp->mnt_data == NULL)
123 			return EIO;
124 		tmp = VFS_TO_TMPFS(mp);
125 
126 		if (args.ta_fspec == NULL) {
127 			/* Update NFS export information. */
128 			return vfs_export(mp, &tmp->tm_export, &args.ta_export);
129 		}
130 
131 		/* XXX: There is no support yet to update file system
132 		 * settings.  Should be added. */
133 
134 		return EOPNOTSUPP;
135 	}
136 
137 	if (args.ta_version != TMPFS_ARGS_VERSION)
138 		return EINVAL;
139 
140 	/* Do not allow mounts if we do not have enough memory to preserve
141 	 * the minimum reserved pages. */
142 	if (tmpfs_mem_info(TRUE) < TMPFS_PAGES_RESERVED)
143 		return EINVAL;
144 
145 	/* Get the maximum number of memory pages this file system is
146 	 * allowed to use, based on the maximum size the user passed in
147 	 * the mount structure.  A value of zero is treated as if the
148 	 * maximum available space was requested. */
149 	if (args.ta_size_max == 0)
150 		pages = SIZE_MAX;
151 	else
152 		pages = args.ta_size_max / PAGE_SIZE +
153 		    (args.ta_size_max % PAGE_SIZE == 0 ? 0 : 1);
154 
155 	if (args.ta_nodes_max == 0)
156 		nodes = pages * PAGE_SIZE / 1024;
157 	else
158 		nodes = args.ta_nodes_max;
159 
160 	/* Allocate the tmpfs mount structure and fill it. */
161 	tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
162 	    M_TMPFSMNT, M_WAITOK);
163 	KASSERT(tmp != NULL);
164 
165 	tmp->tm_nodes_max = nodes;
166 	tmp->tm_nodes_last = 0;
167 	LIST_INIT(&tmp->tm_nodes_used);
168 	LIST_INIT(&tmp->tm_nodes_avail);
169 
170 	tmp->tm_pages_max = pages;
171 	tmp->tm_pages_used = 0;
172 	tmpfs_pool_init(&tmp->tm_dirent_pool, sizeof(struct tmpfs_dirent),
173 	    "dirent", tmp);
174 	tmpfs_pool_init(&tmp->tm_node_pool, sizeof(struct tmpfs_node),
175 	    "node", tmp);
176 	tmpfs_str_pool_init(&tmp->tm_str_pool, tmp);
177 	bzero(&tmp->tm_export, sizeof(struct netexport));
178 
179 	/* Allocate the root node. */
180 	error = tmpfs_alloc_node(tmp, VDIR, args.ta_root_uid,
181 	    args.ta_root_gid, args.ta_root_mode, NULL, NULL, VNOVAL, p,
182 	    &root);
183 	KASSERT(error == 0 && root != NULL);
184 	tmp->tm_root = root;
185 
186 	mp->mnt_data = tmp;
187 	mp->mnt_flag |= MNT_LOCAL;
188 	mp->mnt_stat.f_namemax = MAXNAMLEN;
189 	vfs_getnewfsid(mp);
190 
191 	return set_statvfs_info(path, UIO_USERSPACE, "tmpfs", UIO_SYSSPACE,
192 	    mp, p);
193 }
194 
195 /* --------------------------------------------------------------------- */
196 
197 static int
198 tmpfs_start(struct mount *mp, int flags, struct proc *p)
199 {
200 
201 	return 0;
202 }
203 
204 /* --------------------------------------------------------------------- */
205 
206 /* ARGSUSED2 */
207 static int
208 tmpfs_unmount(struct mount *mp, int mntflags, struct proc *p)
209 {
210 	int error;
211 	int flags = 0;
212 	struct tmpfs_mount *tmp;
213 	struct tmpfs_node *node;
214 
215 	/* Handle forced unmounts. */
216 	if (mntflags & MNT_FORCE)
217 		flags |= FORCECLOSE;
218 
219 	/* Finalize all pending I/O. */
220 	error = vflush(mp, NULL, flags);
221 	if (error != 0)
222 		return error;
223 
224 	tmp = VFS_TO_TMPFS(mp);
225 
226 	/* Free all associated data.  The loop iterates over the linked list
227 	 * we have containing all used nodes.  For each of them that is
228 	 * a directory, we free all its directory entries.  Note that after
229 	 * freeing a node, it will automatically go to the available list,
230 	 * so we will later have to iterate over it to release its items. */
231 	node = LIST_FIRST(&tmp->tm_nodes_used);
232 	while (node != NULL) {
233 		struct tmpfs_node *next;
234 
235 		if (node->tn_type == VDIR) {
236 			struct tmpfs_dirent *de;
237 
238 			de = TAILQ_FIRST(&node->tn_dir);
239 			while (de != NULL) {
240 				struct tmpfs_dirent *nde;
241 
242 				nde = TAILQ_NEXT(de, td_entries);
243 				tmpfs_free_dirent(tmp, de, FALSE);
244 				de = nde;
245 				node->tn_size -= sizeof(struct tmpfs_dirent);
246 			}
247 		}
248 
249 		next = LIST_NEXT(node, tn_entries);
250 		tmpfs_free_node(tmp, node);
251 		node = next;
252 	}
253 	node = LIST_FIRST(&tmp->tm_nodes_avail);
254 	while (node != NULL) {
255 		struct tmpfs_node *next;
256 
257 		next = LIST_NEXT(node, tn_entries);
258 		LIST_REMOVE(node, tn_entries);
259 		TMPFS_POOL_PUT(&tmp->tm_node_pool, node);
260 		node = next;
261 	}
262 
263 	tmpfs_pool_destroy(&tmp->tm_dirent_pool);
264 	tmpfs_pool_destroy(&tmp->tm_node_pool);
265 	tmpfs_str_pool_destroy(&tmp->tm_str_pool);
266 
267 	KASSERT(tmp->tm_pages_used == 0);
268 
269 	/* Throw away the tmpfs_mount structure. */
270 	free(mp->mnt_data, M_TMPFSMNT);
271 	mp->mnt_data = NULL;
272 
273 	return 0;
274 }
275 
276 /* --------------------------------------------------------------------- */
277 
278 static int
279 tmpfs_root(struct mount *mp, struct vnode **vpp)
280 {
281 
282 	return tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, vpp);
283 }
284 
285 /* --------------------------------------------------------------------- */
286 
287 static int
288 tmpfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg,
289     struct proc *p)
290 {
291 
292 	printf("tmpfs_quotactl called; need for it unknown yet\n");
293 	return EOPNOTSUPP;
294 }
295 
296 /* --------------------------------------------------------------------- */
297 
298 static int
299 tmpfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
300 {
301 
302 	printf("tmpfs_vget called; need for it unknown yet\n");
303 	return EOPNOTSUPP;
304 }
305 
306 /* --------------------------------------------------------------------- */
307 
308 static int
309 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
310 {
311 	boolean_t found;
312 	struct tmpfs_fid *tfhp;
313 	struct tmpfs_mount *tmp;
314 	struct tmpfs_node *node;
315 
316 	tmp = VFS_TO_TMPFS(mp);
317 
318 	tfhp = (struct tmpfs_fid *)fhp;
319 	if (tfhp->tf_len != sizeof(struct tmpfs_fid))
320 		return EINVAL;
321 
322 	if (tfhp->tf_id >= tmp->tm_nodes_max)
323 		return EINVAL;
324 
325 	found = FALSE;
326 	LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
327 		if (node->tn_id == tfhp->tf_id &&
328 		    node->tn_gen == tfhp->tf_gen) {
329 			found = TRUE;
330 			break;
331 		}
332 	}
333 
334 	return found ? tmpfs_alloc_vp(mp, node, vpp) : EINVAL;
335 }
336 
337 /* --------------------------------------------------------------------- */
338 
339 static int
340 tmpfs_vptofh(struct vnode *vp, struct fid *fhp)
341 {
342 	struct tmpfs_fid *tfhp;
343 	struct tmpfs_node *node;
344 
345 	tfhp = (struct tmpfs_fid *)fhp;
346 	node = VP_TO_TMPFS_NODE(vp);
347 
348 	tfhp->tf_len = sizeof(struct tmpfs_fid);
349 	tfhp->tf_id = node->tn_id;
350 	tfhp->tf_gen = node->tn_gen;
351 
352 	return 0;
353 }
354 
355 /* --------------------------------------------------------------------- */
356 
357 /* ARGSUSED2 */
358 static int
359 tmpfs_statvfs(struct mount *mp, struct statvfs *sbp, struct proc *p)
360 {
361 	fsfilcnt_t freenodes, usednodes;
362 	struct tmpfs_mount *tmp;
363 	struct tmpfs_node *dummy;
364 
365 	tmp = VFS_TO_TMPFS(mp);
366 
367 	sbp->f_iosize = sbp->f_frsize = sbp->f_bsize = PAGE_SIZE;
368 
369 	sbp->f_blocks = TMPFS_PAGES_MAX(tmp);
370 	sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp);
371 	sbp->f_bresvd = 0;
372 
373 	freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_last,
374 	    TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node));
375 	LIST_FOREACH(dummy, &tmp->tm_nodes_avail, tn_entries)
376 		freenodes++;
377 
378 	usednodes = 0;
379 	LIST_FOREACH(dummy, &tmp->tm_nodes_used, tn_entries)
380 		usednodes++;
381 
382 	sbp->f_files = freenodes + usednodes;
383 	sbp->f_favail = sbp->f_ffree = freenodes;
384 	sbp->f_fresvd = 0;
385 
386 	copy_statvfs_info(sbp, mp);
387 
388 	return 0;
389 }
390 
391 /* --------------------------------------------------------------------- */
392 
393 /* ARGSUSED0 */
394 static int
395 tmpfs_sync(struct mount *mp, int waitfor, struct ucred *uc, struct proc *p)
396 {
397 
398 	return 0;
399 }
400 
401 /* --------------------------------------------------------------------- */
402 
403 static void
404 tmpfs_init(void)
405 {
406 
407 #ifdef _LKM
408 	malloc_type_attach(M_TMPFSMNT);
409 #endif
410 }
411 
412 /* --------------------------------------------------------------------- */
413 
414 static void
415 tmpfs_done(void)
416 {
417 
418 #ifdef _LKM
419 	malloc_type_detach(M_TMPFSMNT);
420 #endif
421 }
422 
423 /* --------------------------------------------------------------------- */
424 
425 static int
426 tmpfs_checkexp(struct mount *mp, struct mbuf *mb, int *wh,
427     struct ucred **anon)
428 {
429 	struct netcred *np;
430 	struct tmpfs_mount *tmp;
431 
432 	tmp = VFS_TO_TMPFS(mp);
433 
434 	np = vfs_export_lookup(mp, &tmp->tm_export, mb);
435 	if (np != NULL) {
436 		*wh = np->netc_exflags;
437 		*anon = &np->netc_anon;
438 	}
439 
440 	return np == NULL ? EACCES : 0;
441 }
442 
443 /* --------------------------------------------------------------------- */
444 
445 static int
446 tmpfs_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ctime)
447 {
448 
449 	return EOPNOTSUPP;
450 }
451 
452 /* --------------------------------------------------------------------- */
453 
454 /*
455  * tmpfs vfs operations.
456  */
457 
458 extern const struct vnodeopv_desc tmpfs_fifoop_opv_desc;
459 extern const struct vnodeopv_desc tmpfs_specop_opv_desc;
460 extern const struct vnodeopv_desc tmpfs_vnodeop_opv_desc;
461 
462 const struct vnodeopv_desc * const tmpfs_vnodeopv_descs[] = {
463 	&tmpfs_fifoop_opv_desc,
464 	&tmpfs_specop_opv_desc,
465 	&tmpfs_vnodeop_opv_desc,
466 	NULL,
467 };
468 
469 struct vfsops tmpfs_vfsops = {
470 	MOUNT_TMPFS,			/* vfs_name */
471 	tmpfs_mount,			/* vfs_mount */
472 	tmpfs_start,			/* vfs_start */
473 	tmpfs_unmount,			/* vfs_unmount */
474 	tmpfs_root,			/* vfs_root */
475 	tmpfs_quotactl,			/* vfs_quotactl */
476 	tmpfs_statvfs,			/* vfs_statvfs */
477 	tmpfs_sync,			/* vfs_sync */
478 	tmpfs_vget,			/* vfs_vget */
479 	tmpfs_fhtovp,			/* vfs_fhtovp */
480 	tmpfs_vptofh,			/* vfs_vptofh */
481 	tmpfs_init,			/* vfs_init */
482 	NULL,				/* vfs_reinit */
483 	tmpfs_done,			/* vfs_done */
484 	NULL,				/* vfs_wassysctl: deprecated */
485 	NULL,				/* vfs_mountroot */
486 	tmpfs_checkexp,			/* vfs_checkexp */
487 	tmpfs_snapshot,			/* vfs_snapshot */
488 	vfs_stdextattrctl,		/* vfs_extattrctl */
489 	tmpfs_vnodeopv_descs,
490 };
491 VFS_ATTACH(tmpfs_vfsops);
492