1/* $NetBSD: tmpfs_vfsops.c,v 1.10 2005/12/11 12:24:29 christos 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, developed as part of Google's Summer of Code
9 * 2005 program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40/*
41 * Efficient memory file system.
42 *
43 * tmpfs is a file system that uses NetBSD's virtual memory sub-system
44 * (the well-known UVM) to store file data and metadata in an efficient
45 * way. This means that it does not follow the structure of an on-disk
46 * file system because it simply does not need to. Instead, it uses
47 * memory-specific data structures and algorithms to automatically
48 * allocate and release resources.
49 */
50#include <sys/cdefs.h>
| 1/* $NetBSD: tmpfs_vfsops.c,v 1.10 2005/12/11 12:24:29 christos 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, developed as part of Google's Summer of Code
9 * 2005 program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40/*
41 * Efficient memory file system.
42 *
43 * tmpfs is a file system that uses NetBSD's virtual memory sub-system
44 * (the well-known UVM) to store file data and metadata in an efficient
45 * way. This means that it does not follow the structure of an on-disk
46 * file system because it simply does not need to. Instead, it uses
47 * memory-specific data structures and algorithms to automatically
48 * allocate and release resources.
49 */
50#include <sys/cdefs.h>
|
52
53#include <sys/param.h>
54#include <sys/limits.h>
55#include <sys/lock.h>
56#include <sys/mutex.h>
57#include <sys/kernel.h>
58#include <sys/stat.h>
59#include <sys/systm.h>
60#include <sys/sysctl.h>
61
62#include <vm/vm.h>
63#include <vm/vm_object.h>
64#include <vm/vm_param.h>
65
66#include <fs/tmpfs/tmpfs.h>
67
68/*
69 * Default permission for root node
70 */
71#define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
72
73MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures");
74MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names");
75
76/* --------------------------------------------------------------------- */
77
78static int tmpfs_mount(struct mount *, struct thread *);
79static int tmpfs_unmount(struct mount *, int, struct thread *);
80static int tmpfs_root(struct mount *, int flags, struct vnode **,
81 struct thread *);
82static int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **);
83static int tmpfs_statfs(struct mount *, struct statfs *, struct thread *);
84
85/* --------------------------------------------------------------------- */
86
87static const char *tmpfs_opts[] = {
88 "from", "size", "inodes", "uid", "gid", "mode", "export",
89 NULL
90};
91
92/* --------------------------------------------------------------------- */
93
94#define SWI_MAXMIB 3
95
96static u_int
97get_swpgtotal(void)
98{
99 struct xswdev xsd;
100 char *sname = "vm.swap_info";
101 int soid[SWI_MAXMIB], oid[2];
102 u_int unswdev, total, dmmax, nswapdev;
103 size_t mibi, len;
104
105 total = 0;
106
107 len = sizeof(dmmax);
108 if (kernel_sysctlbyname(curthread, "vm.dmmax", &dmmax, &len,
109 NULL, 0, NULL, 0) != 0)
110 return total;
111
112 len = sizeof(nswapdev);
113 if (kernel_sysctlbyname(curthread, "vm.nswapdev",
114 &nswapdev, &len,
115 NULL, 0, NULL, 0) != 0)
116 return total;
117
118 mibi = (SWI_MAXMIB - 1) * sizeof(int);
119 oid[0] = 0;
120 oid[1] = 3;
121
122 if (kernel_sysctl(curthread, oid, 2,
123 soid, &mibi, (void *)sname, strlen(sname),
124 NULL, 0) != 0)
125 return total;
126
127 mibi = (SWI_MAXMIB - 1);
128 for (unswdev = 0; unswdev < nswapdev; ++unswdev) {
129 soid[mibi] = unswdev;
130 len = sizeof(struct xswdev);
131 if (kernel_sysctl(curthread,
132 soid, mibi + 1, &xsd, &len, NULL, 0,
133 NULL, 0) != 0)
134 return total;
135 if (len == sizeof(struct xswdev))
136 total += (xsd.xsw_nblks - dmmax);
137 }
138
139 /* Not Reached */
140 return total;
141}
142
143/* --------------------------------------------------------------------- */
144static int
145tmpfs_node_ctor(void *mem, int size, void *arg, int flags)
146{
147 struct tmpfs_node *node = (struct tmpfs_node *)mem;
148
149 node->tn_gen++;
150 node->tn_size = 0;
151 node->tn_status = 0;
152 node->tn_flags = 0;
153 node->tn_links = 0;
154 node->tn_lockf = NULL;
155 node->tn_vnode = NULL;
156 node->tn_vpstate = 0;
| 52
53#include <sys/param.h>
54#include <sys/limits.h>
55#include <sys/lock.h>
56#include <sys/mutex.h>
57#include <sys/kernel.h>
58#include <sys/stat.h>
59#include <sys/systm.h>
60#include <sys/sysctl.h>
61
62#include <vm/vm.h>
63#include <vm/vm_object.h>
64#include <vm/vm_param.h>
65
66#include <fs/tmpfs/tmpfs.h>
67
68/*
69 * Default permission for root node
70 */
71#define TMPFS_DEFAULT_ROOT_MODE (S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
72
73MALLOC_DEFINE(M_TMPFSMNT, "tmpfs mount", "tmpfs mount structures");
74MALLOC_DEFINE(M_TMPFSNAME, "tmpfs name", "tmpfs file names");
75
76/* --------------------------------------------------------------------- */
77
78static int tmpfs_mount(struct mount *, struct thread *);
79static int tmpfs_unmount(struct mount *, int, struct thread *);
80static int tmpfs_root(struct mount *, int flags, struct vnode **,
81 struct thread *);
82static int tmpfs_fhtovp(struct mount *, struct fid *, struct vnode **);
83static int tmpfs_statfs(struct mount *, struct statfs *, struct thread *);
84
85/* --------------------------------------------------------------------- */
86
87static const char *tmpfs_opts[] = {
88 "from", "size", "inodes", "uid", "gid", "mode", "export",
89 NULL
90};
91
92/* --------------------------------------------------------------------- */
93
94#define SWI_MAXMIB 3
95
96static u_int
97get_swpgtotal(void)
98{
99 struct xswdev xsd;
100 char *sname = "vm.swap_info";
101 int soid[SWI_MAXMIB], oid[2];
102 u_int unswdev, total, dmmax, nswapdev;
103 size_t mibi, len;
104
105 total = 0;
106
107 len = sizeof(dmmax);
108 if (kernel_sysctlbyname(curthread, "vm.dmmax", &dmmax, &len,
109 NULL, 0, NULL, 0) != 0)
110 return total;
111
112 len = sizeof(nswapdev);
113 if (kernel_sysctlbyname(curthread, "vm.nswapdev",
114 &nswapdev, &len,
115 NULL, 0, NULL, 0) != 0)
116 return total;
117
118 mibi = (SWI_MAXMIB - 1) * sizeof(int);
119 oid[0] = 0;
120 oid[1] = 3;
121
122 if (kernel_sysctl(curthread, oid, 2,
123 soid, &mibi, (void *)sname, strlen(sname),
124 NULL, 0) != 0)
125 return total;
126
127 mibi = (SWI_MAXMIB - 1);
128 for (unswdev = 0; unswdev < nswapdev; ++unswdev) {
129 soid[mibi] = unswdev;
130 len = sizeof(struct xswdev);
131 if (kernel_sysctl(curthread,
132 soid, mibi + 1, &xsd, &len, NULL, 0,
133 NULL, 0) != 0)
134 return total;
135 if (len == sizeof(struct xswdev))
136 total += (xsd.xsw_nblks - dmmax);
137 }
138
139 /* Not Reached */
140 return total;
141}
142
143/* --------------------------------------------------------------------- */
144static int
145tmpfs_node_ctor(void *mem, int size, void *arg, int flags)
146{
147 struct tmpfs_node *node = (struct tmpfs_node *)mem;
148
149 node->tn_gen++;
150 node->tn_size = 0;
151 node->tn_status = 0;
152 node->tn_flags = 0;
153 node->tn_links = 0;
154 node->tn_lockf = NULL;
155 node->tn_vnode = NULL;
156 node->tn_vpstate = 0;
|
158
159 return (0);
160}
161
162static void
163tmpfs_node_dtor(void *mem, int size, void *arg)
164{
165 struct tmpfs_node *node = (struct tmpfs_node *)mem;
166 node->tn_type = VNON;
167}
168
169static int
170tmpfs_node_init(void *mem, int size, int flags)
171{
172 struct tmpfs_node *node = (struct tmpfs_node *)mem;
173 node->tn_id = 0;
174
175 mtx_init(&node->tn_interlock, "tmpfs node interlock", NULL, MTX_DEF);
176 node->tn_gen = arc4random();
177
178 return (0);
179}
180
181static void
182tmpfs_node_fini(void *mem, int size)
183{
184 struct tmpfs_node *node = (struct tmpfs_node *)mem;
185
186 mtx_destroy(&node->tn_interlock);
187}
188
189static int
190tmpfs_mount(struct mount *mp, struct thread *td)
191{
192 struct tmpfs_mount *tmp;
193 struct tmpfs_node *root;
194 size_t pages, mem_size;
195 ino_t nodes;
196 int error;
197 /* Size counters. */
198 ino_t nodes_max;
199 off_t size_max;
200
201 /* Root node attributes. */
202 uid_t root_uid;
203 gid_t root_gid;
204 mode_t root_mode;
205
206 struct vattr va;
207
208 if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts))
209 return (EINVAL);
210
211 if (mp->mnt_flag & MNT_UPDATE) {
212 /* XXX: There is no support yet to update file system
213 * settings. Should be added. */
214
215 return EOPNOTSUPP;
216 }
217
218 printf("WARNING: TMPFS is considered to be a highly experimental "
219 "feature in FreeBSD.\n");
220
221 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY, td);
222 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred, td);
223 VOP_UNLOCK(mp->mnt_vnodecovered, 0, td);
224 if (error)
225 return (error);
226
227 if (mp->mnt_cred->cr_ruid != 0 ||
228 vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1)
229 root_gid = va.va_gid;
230 if (mp->mnt_cred->cr_ruid != 0 ||
231 vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1)
232 root_uid = va.va_uid;
233 if (mp->mnt_cred->cr_ruid != 0 ||
234 vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1)
235 root_mode = va.va_mode;
236 if (vfs_scanopt(mp->mnt_optnew, "inodes", "%d", &nodes_max) != 1)
237 nodes_max = 0;
238 if (vfs_scanopt(mp->mnt_optnew, "size", "%qu", &size_max) != 1)
239 size_max = 0;
240
241 /* Do not allow mounts if we do not have enough memory to preserve
242 * the minimum reserved pages. */
243 mem_size = cnt.v_free_count + cnt.v_inactive_count + get_swpgtotal();
244 mem_size -= mem_size > cnt.v_wire_count ? cnt.v_wire_count : mem_size;
245 if (mem_size < TMPFS_PAGES_RESERVED)
246 return ENOSPC;
247
248 /* Get the maximum number of memory pages this file system is
249 * allowed to use, based on the maximum size the user passed in
250 * the mount structure. A value of zero is treated as if the
251 * maximum available space was requested. */
252 if (size_max < PAGE_SIZE || size_max >= SIZE_MAX)
253 pages = SIZE_MAX;
254 else
255 pages = howmany(size_max, PAGE_SIZE);
256 MPASS(pages > 0);
257
258 if (nodes_max <= 3)
259 nodes = 3 + pages * PAGE_SIZE / 1024;
260 else
261 nodes = nodes_max;
262 MPASS(nodes >= 3);
263
264 /* Allocate the tmpfs mount structure and fill it. */
265 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
266 M_TMPFSMNT, M_WAITOK | M_ZERO);
267
268 mtx_init(&tmp->allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF);
269 tmp->tm_nodes_max = nodes;
270 tmp->tm_nodes_inuse = 0;
271 tmp->tm_maxfilesize = (u_int64_t)(cnt.v_page_count + get_swpgtotal()) * PAGE_SIZE;
272 LIST_INIT(&tmp->tm_nodes_used);
273
274 tmp->tm_pages_max = pages;
275 tmp->tm_pages_used = 0;
276 tmp->tm_ino_unr = new_unrhdr(2, INT_MAX, &tmp->allnode_lock);
277 tmp->tm_dirent_pool = uma_zcreate("TMPFS dirent",
278 sizeof(struct tmpfs_dirent),
279 NULL, NULL, NULL, NULL,
280 UMA_ALIGN_PTR, 0);
281 tmp->tm_node_pool = uma_zcreate("TMPFS node",
282 sizeof(struct tmpfs_node),
283 tmpfs_node_ctor, tmpfs_node_dtor,
284 tmpfs_node_init, tmpfs_node_fini,
285 UMA_ALIGN_PTR, 0);
286
287 /* Allocate the root node. */
288 error = tmpfs_alloc_node(tmp, VDIR, root_uid,
289 root_gid, root_mode & ALLPERMS, NULL, NULL,
290 VNOVAL, td, &root);
291
292 if (error != 0 || root == NULL) {
293 uma_zdestroy(tmp->tm_node_pool);
294 uma_zdestroy(tmp->tm_dirent_pool);
295 delete_unrhdr(tmp->tm_ino_unr);
296 free(tmp, M_TMPFSMNT);
297 return error;
298 }
299 KASSERT(root->tn_id == 2, ("tmpfs root with invalid ino: %d", root->tn_id));
300 tmp->tm_root = root;
301
302 MNT_ILOCK(mp);
303 mp->mnt_flag |= MNT_LOCAL;
304 mp->mnt_kern_flag |= MNTK_MPSAFE;
305 MNT_IUNLOCK(mp);
306
307 mp->mnt_data = tmp;
308 mp->mnt_stat.f_namemax = MAXNAMLEN;
309 vfs_getnewfsid(mp);
310 vfs_mountedfrom(mp, "tmpfs");
311
312 return 0;
313}
314
315/* --------------------------------------------------------------------- */
316
317/* ARGSUSED2 */
318static int
319tmpfs_unmount(struct mount *mp, int mntflags, struct thread *l)
320{
321 int error;
322 int flags = 0;
323 struct tmpfs_mount *tmp;
324 struct tmpfs_node *node;
325
326 /* Handle forced unmounts. */
327 if (mntflags & MNT_FORCE)
328 flags |= FORCECLOSE;
329
330 /* Finalize all pending I/O. */
331 error = vflush(mp, 0, flags, l);
332 if (error != 0)
333 return error;
334
335 tmp = VFS_TO_TMPFS(mp);
336
337 /* Free all associated data. The loop iterates over the linked list
338 * we have containing all used nodes. For each of them that is
339 * a directory, we free all its directory entries. Note that after
340 * freeing a node, it will automatically go to the available list,
341 * so we will later have to iterate over it to release its items. */
342 node = LIST_FIRST(&tmp->tm_nodes_used);
343 while (node != NULL) {
344 struct tmpfs_node *next;
345
346 if (node->tn_type == VDIR) {
347 struct tmpfs_dirent *de;
348
349 de = TAILQ_FIRST(&node->tn_dir.tn_dirhead);
350 while (de != NULL) {
351 struct tmpfs_dirent *nde;
352
353 nde = TAILQ_NEXT(de, td_entries);
354 tmpfs_free_dirent(tmp, de, FALSE);
355 de = nde;
356 node->tn_size -= sizeof(struct tmpfs_dirent);
357 }
358 }
359
360 next = LIST_NEXT(node, tn_entries);
361 tmpfs_free_node(tmp, node);
362 node = next;
363 }
364
365 uma_zdestroy(tmp->tm_dirent_pool);
366 uma_zdestroy(tmp->tm_node_pool);
367 delete_unrhdr(tmp->tm_ino_unr);
368
369 mtx_destroy(&tmp->allnode_lock);
370 MPASS(tmp->tm_pages_used == 0);
371 MPASS(tmp->tm_nodes_inuse == 0);
372
373 /* Throw away the tmpfs_mount structure. */
374 free(mp->mnt_data, M_TMPFSMNT);
375 mp->mnt_data = NULL;
376
377 MNT_ILOCK(mp);
378 mp->mnt_flag &= ~MNT_LOCAL;
379 MNT_IUNLOCK(mp);
380 return 0;
381}
382
383/* --------------------------------------------------------------------- */
384
385static int
386tmpfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
387{
388 int error;
389 error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp, td);
390
391 if (!error)
392 (*vpp)->v_vflag |= VV_ROOT;
393
394 return error;
395}
396
397/* --------------------------------------------------------------------- */
398
399static int
400tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
401{
402 boolean_t found;
403 struct tmpfs_fid *tfhp;
404 struct tmpfs_mount *tmp;
405 struct tmpfs_node *node;
406
407 tmp = VFS_TO_TMPFS(mp);
408
409 tfhp = (struct tmpfs_fid *)fhp;
410 if (tfhp->tf_len != sizeof(struct tmpfs_fid))
411 return EINVAL;
412
413 if (tfhp->tf_id >= tmp->tm_nodes_max)
414 return EINVAL;
415
416 found = FALSE;
417
418 TMPFS_LOCK(tmp);
419 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
420 if (node->tn_id == tfhp->tf_id &&
421 node->tn_gen == tfhp->tf_gen) {
422 found = TRUE;
423 break;
424 }
425 }
426 TMPFS_UNLOCK(tmp);
427
428 if (found)
429 return (tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp, curthread));
430
431 return (EINVAL);
432}
433
434/* --------------------------------------------------------------------- */
435
436/* ARGSUSED2 */
437static int
438tmpfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *l)
439{
440 fsfilcnt_t freenodes;
441 struct tmpfs_mount *tmp;
442
443 tmp = VFS_TO_TMPFS(mp);
444
445 sbp->f_iosize = PAGE_SIZE;
446 sbp->f_bsize = PAGE_SIZE;
447
448 sbp->f_blocks = TMPFS_PAGES_MAX(tmp);
449 sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp);
450
451 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_inuse,
452 TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node));
453
454 sbp->f_files = freenodes + tmp->tm_nodes_inuse;
455 sbp->f_ffree = freenodes;
456 /* sbp->f_owner = tmp->tn_uid; */
457
458 return 0;
459}
460
461/* --------------------------------------------------------------------- */
462
463/*
464 * tmpfs vfs operations.
465 */
466
467struct vfsops tmpfs_vfsops = {
468 .vfs_mount = tmpfs_mount,
469 .vfs_unmount = tmpfs_unmount,
470 .vfs_root = tmpfs_root,
471 .vfs_statfs = tmpfs_statfs,
472 .vfs_fhtovp = tmpfs_fhtovp,
473};
474VFS_SET(tmpfs_vfsops, tmpfs, 0);
| 157
158 return (0);
159}
160
161static void
162tmpfs_node_dtor(void *mem, int size, void *arg)
163{
164 struct tmpfs_node *node = (struct tmpfs_node *)mem;
165 node->tn_type = VNON;
166}
167
168static int
169tmpfs_node_init(void *mem, int size, int flags)
170{
171 struct tmpfs_node *node = (struct tmpfs_node *)mem;
172 node->tn_id = 0;
173
174 mtx_init(&node->tn_interlock, "tmpfs node interlock", NULL, MTX_DEF);
175 node->tn_gen = arc4random();
176
177 return (0);
178}
179
180static void
181tmpfs_node_fini(void *mem, int size)
182{
183 struct tmpfs_node *node = (struct tmpfs_node *)mem;
184
185 mtx_destroy(&node->tn_interlock);
186}
187
188static int
189tmpfs_mount(struct mount *mp, struct thread *td)
190{
191 struct tmpfs_mount *tmp;
192 struct tmpfs_node *root;
193 size_t pages, mem_size;
194 ino_t nodes;
195 int error;
196 /* Size counters. */
197 ino_t nodes_max;
198 off_t size_max;
199
200 /* Root node attributes. */
201 uid_t root_uid;
202 gid_t root_gid;
203 mode_t root_mode;
204
205 struct vattr va;
206
207 if (vfs_filteropt(mp->mnt_optnew, tmpfs_opts))
208 return (EINVAL);
209
210 if (mp->mnt_flag & MNT_UPDATE) {
211 /* XXX: There is no support yet to update file system
212 * settings. Should be added. */
213
214 return EOPNOTSUPP;
215 }
216
217 printf("WARNING: TMPFS is considered to be a highly experimental "
218 "feature in FreeBSD.\n");
219
220 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY, td);
221 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred, td);
222 VOP_UNLOCK(mp->mnt_vnodecovered, 0, td);
223 if (error)
224 return (error);
225
226 if (mp->mnt_cred->cr_ruid != 0 ||
227 vfs_scanopt(mp->mnt_optnew, "gid", "%d", &root_gid) != 1)
228 root_gid = va.va_gid;
229 if (mp->mnt_cred->cr_ruid != 0 ||
230 vfs_scanopt(mp->mnt_optnew, "uid", "%d", &root_uid) != 1)
231 root_uid = va.va_uid;
232 if (mp->mnt_cred->cr_ruid != 0 ||
233 vfs_scanopt(mp->mnt_optnew, "mode", "%ho", &root_mode) != 1)
234 root_mode = va.va_mode;
235 if (vfs_scanopt(mp->mnt_optnew, "inodes", "%d", &nodes_max) != 1)
236 nodes_max = 0;
237 if (vfs_scanopt(mp->mnt_optnew, "size", "%qu", &size_max) != 1)
238 size_max = 0;
239
240 /* Do not allow mounts if we do not have enough memory to preserve
241 * the minimum reserved pages. */
242 mem_size = cnt.v_free_count + cnt.v_inactive_count + get_swpgtotal();
243 mem_size -= mem_size > cnt.v_wire_count ? cnt.v_wire_count : mem_size;
244 if (mem_size < TMPFS_PAGES_RESERVED)
245 return ENOSPC;
246
247 /* Get the maximum number of memory pages this file system is
248 * allowed to use, based on the maximum size the user passed in
249 * the mount structure. A value of zero is treated as if the
250 * maximum available space was requested. */
251 if (size_max < PAGE_SIZE || size_max >= SIZE_MAX)
252 pages = SIZE_MAX;
253 else
254 pages = howmany(size_max, PAGE_SIZE);
255 MPASS(pages > 0);
256
257 if (nodes_max <= 3)
258 nodes = 3 + pages * PAGE_SIZE / 1024;
259 else
260 nodes = nodes_max;
261 MPASS(nodes >= 3);
262
263 /* Allocate the tmpfs mount structure and fill it. */
264 tmp = (struct tmpfs_mount *)malloc(sizeof(struct tmpfs_mount),
265 M_TMPFSMNT, M_WAITOK | M_ZERO);
266
267 mtx_init(&tmp->allnode_lock, "tmpfs allnode lock", NULL, MTX_DEF);
268 tmp->tm_nodes_max = nodes;
269 tmp->tm_nodes_inuse = 0;
270 tmp->tm_maxfilesize = (u_int64_t)(cnt.v_page_count + get_swpgtotal()) * PAGE_SIZE;
271 LIST_INIT(&tmp->tm_nodes_used);
272
273 tmp->tm_pages_max = pages;
274 tmp->tm_pages_used = 0;
275 tmp->tm_ino_unr = new_unrhdr(2, INT_MAX, &tmp->allnode_lock);
276 tmp->tm_dirent_pool = uma_zcreate("TMPFS dirent",
277 sizeof(struct tmpfs_dirent),
278 NULL, NULL, NULL, NULL,
279 UMA_ALIGN_PTR, 0);
280 tmp->tm_node_pool = uma_zcreate("TMPFS node",
281 sizeof(struct tmpfs_node),
282 tmpfs_node_ctor, tmpfs_node_dtor,
283 tmpfs_node_init, tmpfs_node_fini,
284 UMA_ALIGN_PTR, 0);
285
286 /* Allocate the root node. */
287 error = tmpfs_alloc_node(tmp, VDIR, root_uid,
288 root_gid, root_mode & ALLPERMS, NULL, NULL,
289 VNOVAL, td, &root);
290
291 if (error != 0 || root == NULL) {
292 uma_zdestroy(tmp->tm_node_pool);
293 uma_zdestroy(tmp->tm_dirent_pool);
294 delete_unrhdr(tmp->tm_ino_unr);
295 free(tmp, M_TMPFSMNT);
296 return error;
297 }
298 KASSERT(root->tn_id == 2, ("tmpfs root with invalid ino: %d", root->tn_id));
299 tmp->tm_root = root;
300
301 MNT_ILOCK(mp);
302 mp->mnt_flag |= MNT_LOCAL;
303 mp->mnt_kern_flag |= MNTK_MPSAFE;
304 MNT_IUNLOCK(mp);
305
306 mp->mnt_data = tmp;
307 mp->mnt_stat.f_namemax = MAXNAMLEN;
308 vfs_getnewfsid(mp);
309 vfs_mountedfrom(mp, "tmpfs");
310
311 return 0;
312}
313
314/* --------------------------------------------------------------------- */
315
316/* ARGSUSED2 */
317static int
318tmpfs_unmount(struct mount *mp, int mntflags, struct thread *l)
319{
320 int error;
321 int flags = 0;
322 struct tmpfs_mount *tmp;
323 struct tmpfs_node *node;
324
325 /* Handle forced unmounts. */
326 if (mntflags & MNT_FORCE)
327 flags |= FORCECLOSE;
328
329 /* Finalize all pending I/O. */
330 error = vflush(mp, 0, flags, l);
331 if (error != 0)
332 return error;
333
334 tmp = VFS_TO_TMPFS(mp);
335
336 /* Free all associated data. The loop iterates over the linked list
337 * we have containing all used nodes. For each of them that is
338 * a directory, we free all its directory entries. Note that after
339 * freeing a node, it will automatically go to the available list,
340 * so we will later have to iterate over it to release its items. */
341 node = LIST_FIRST(&tmp->tm_nodes_used);
342 while (node != NULL) {
343 struct tmpfs_node *next;
344
345 if (node->tn_type == VDIR) {
346 struct tmpfs_dirent *de;
347
348 de = TAILQ_FIRST(&node->tn_dir.tn_dirhead);
349 while (de != NULL) {
350 struct tmpfs_dirent *nde;
351
352 nde = TAILQ_NEXT(de, td_entries);
353 tmpfs_free_dirent(tmp, de, FALSE);
354 de = nde;
355 node->tn_size -= sizeof(struct tmpfs_dirent);
356 }
357 }
358
359 next = LIST_NEXT(node, tn_entries);
360 tmpfs_free_node(tmp, node);
361 node = next;
362 }
363
364 uma_zdestroy(tmp->tm_dirent_pool);
365 uma_zdestroy(tmp->tm_node_pool);
366 delete_unrhdr(tmp->tm_ino_unr);
367
368 mtx_destroy(&tmp->allnode_lock);
369 MPASS(tmp->tm_pages_used == 0);
370 MPASS(tmp->tm_nodes_inuse == 0);
371
372 /* Throw away the tmpfs_mount structure. */
373 free(mp->mnt_data, M_TMPFSMNT);
374 mp->mnt_data = NULL;
375
376 MNT_ILOCK(mp);
377 mp->mnt_flag &= ~MNT_LOCAL;
378 MNT_IUNLOCK(mp);
379 return 0;
380}
381
382/* --------------------------------------------------------------------- */
383
384static int
385tmpfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
386{
387 int error;
388 error = tmpfs_alloc_vp(mp, VFS_TO_TMPFS(mp)->tm_root, flags, vpp, td);
389
390 if (!error)
391 (*vpp)->v_vflag |= VV_ROOT;
392
393 return error;
394}
395
396/* --------------------------------------------------------------------- */
397
398static int
399tmpfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
400{
401 boolean_t found;
402 struct tmpfs_fid *tfhp;
403 struct tmpfs_mount *tmp;
404 struct tmpfs_node *node;
405
406 tmp = VFS_TO_TMPFS(mp);
407
408 tfhp = (struct tmpfs_fid *)fhp;
409 if (tfhp->tf_len != sizeof(struct tmpfs_fid))
410 return EINVAL;
411
412 if (tfhp->tf_id >= tmp->tm_nodes_max)
413 return EINVAL;
414
415 found = FALSE;
416
417 TMPFS_LOCK(tmp);
418 LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
419 if (node->tn_id == tfhp->tf_id &&
420 node->tn_gen == tfhp->tf_gen) {
421 found = TRUE;
422 break;
423 }
424 }
425 TMPFS_UNLOCK(tmp);
426
427 if (found)
428 return (tmpfs_alloc_vp(mp, node, LK_EXCLUSIVE, vpp, curthread));
429
430 return (EINVAL);
431}
432
433/* --------------------------------------------------------------------- */
434
435/* ARGSUSED2 */
436static int
437tmpfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *l)
438{
439 fsfilcnt_t freenodes;
440 struct tmpfs_mount *tmp;
441
442 tmp = VFS_TO_TMPFS(mp);
443
444 sbp->f_iosize = PAGE_SIZE;
445 sbp->f_bsize = PAGE_SIZE;
446
447 sbp->f_blocks = TMPFS_PAGES_MAX(tmp);
448 sbp->f_bavail = sbp->f_bfree = TMPFS_PAGES_AVAIL(tmp);
449
450 freenodes = MIN(tmp->tm_nodes_max - tmp->tm_nodes_inuse,
451 TMPFS_PAGES_AVAIL(tmp) * PAGE_SIZE / sizeof(struct tmpfs_node));
452
453 sbp->f_files = freenodes + tmp->tm_nodes_inuse;
454 sbp->f_ffree = freenodes;
455 /* sbp->f_owner = tmp->tn_uid; */
456
457 return 0;
458}
459
460/* --------------------------------------------------------------------- */
461
462/*
463 * tmpfs vfs operations.
464 */
465
466struct vfsops tmpfs_vfsops = {
467 .vfs_mount = tmpfs_mount,
468 .vfs_unmount = tmpfs_unmount,
469 .vfs_root = tmpfs_root,
470 .vfs_statfs = tmpfs_statfs,
471 .vfs_fhtovp = tmpfs_fhtovp,
472};
473VFS_SET(tmpfs_vfsops, tmpfs, 0);
|