FreeBSD/Linux Kernel Cross Reference
sys/boot/zfs/zfs.c
1 /*-
2 * Copyright (c) 2007 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: releng/8.0/sys/boot/zfs/zfs.c 185938 2008-12-11 16:48:35Z ps $
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/8.0/sys/boot/zfs/zfs.c 185938 2008-12-11 16:48:35Z ps $");
31
32 /*
33 * Stand-alone file reading package.
34 */
35
36 #include <sys/param.h>
37 #include <sys/disklabel.h>
38 #include <sys/time.h>
39 #include <sys/queue.h>
40 #include <stddef.h>
41 #include <stdarg.h>
42 #include <string.h>
43 #include <stand.h>
44 #include <bootstrap.h>
45
46 #include "zfsimpl.c"
47
48 static int zfs_open(const char *path, struct open_file *f);
49 static int zfs_write(struct open_file *f, void *buf, size_t size, size_t *resid);
50 static int zfs_close(struct open_file *f);
51 static int zfs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
52 static off_t zfs_seek(struct open_file *f, off_t offset, int where);
53 static int zfs_stat(struct open_file *f, struct stat *sb);
54 static int zfs_readdir(struct open_file *f, struct dirent *d);
55
56 struct devsw zfs_dev;
57
58 struct fs_ops zfs_fsops = {
59 "zfs",
60 zfs_open,
61 zfs_close,
62 zfs_read,
63 zfs_write,
64 zfs_seek,
65 zfs_stat,
66 zfs_readdir
67 };
68
69 /*
70 * In-core open file.
71 */
72 struct file {
73 off_t f_seekp; /* seek pointer */
74 dnode_phys_t f_dnode;
75 uint64_t f_zap_type; /* zap type for readdir */
76 uint64_t f_num_leafs; /* number of fzap leaf blocks */
77 zap_leaf_phys_t *f_zap_leaf; /* zap leaf buffer */
78 };
79
80 /*
81 * Open a file.
82 */
83 static int
84 zfs_open(const char *upath, struct open_file *f)
85 {
86 spa_t *spa = (spa_t *) f->f_devdata;
87 struct file *fp;
88 int rc;
89
90 if (f->f_dev != &zfs_dev)
91 return (EINVAL);
92
93 rc = zfs_mount_pool(spa);
94 if (rc)
95 return (rc);
96
97 /* allocate file system specific data structure */
98 fp = malloc(sizeof(struct file));
99 bzero(fp, sizeof(struct file));
100 f->f_fsdata = (void *)fp;
101
102 if (spa->spa_root_objset.os_type != DMU_OST_ZFS) {
103 printf("Unexpected object set type %lld\n",
104 spa->spa_root_objset.os_type);
105 rc = EIO;
106 goto out;
107 }
108
109 rc = zfs_lookup(spa, upath, &fp->f_dnode);
110 if (rc)
111 goto out;
112
113 fp->f_seekp = 0;
114 out:
115 if (rc) {
116 f->f_fsdata = NULL;
117 free(fp);
118 }
119 return (rc);
120 }
121
122 static int
123 zfs_close(struct open_file *f)
124 {
125 struct file *fp = (struct file *)f->f_fsdata;
126
127 dnode_cache_obj = 0;
128 f->f_fsdata = (void *)0;
129 if (fp == (struct file *)0)
130 return (0);
131
132 free(fp);
133 return (0);
134 }
135
136 /*
137 * Copy a portion of a file into kernel memory.
138 * Cross block boundaries when necessary.
139 */
140 static int
141 zfs_read(struct open_file *f, void *start, size_t size, size_t *resid /* out */)
142 {
143 spa_t *spa = (spa_t *) f->f_devdata;
144 struct file *fp = (struct file *)f->f_fsdata;
145 const znode_phys_t *zp = (const znode_phys_t *) fp->f_dnode.dn_bonus;
146 size_t n;
147 int rc;
148
149 n = size;
150 if (fp->f_seekp + n > zp->zp_size)
151 n = zp->zp_size - fp->f_seekp;
152
153 rc = dnode_read(spa, &fp->f_dnode, fp->f_seekp, start, n);
154 if (rc)
155 return (rc);
156
157 if (0) {
158 int i;
159 for (i = 0; i < n; i++)
160 putchar(((char*) start)[i]);
161 }
162 fp->f_seekp += n;
163 if (resid)
164 *resid = size - n;
165
166 return (0);
167 }
168
169 /*
170 * Don't be silly - the bootstrap has no business writing anything.
171 */
172 static int
173 zfs_write(struct open_file *f, void *start, size_t size, size_t *resid /* out */)
174 {
175
176 return (EROFS);
177 }
178
179 static off_t
180 zfs_seek(struct open_file *f, off_t offset, int where)
181 {
182 struct file *fp = (struct file *)f->f_fsdata;
183 znode_phys_t *zp = (znode_phys_t *) fp->f_dnode.dn_bonus;
184
185 switch (where) {
186 case SEEK_SET:
187 fp->f_seekp = offset;
188 break;
189 case SEEK_CUR:
190 fp->f_seekp += offset;
191 break;
192 case SEEK_END:
193 fp->f_seekp = zp->zp_size - offset;
194 break;
195 default:
196 errno = EINVAL;
197 return (-1);
198 }
199 return (fp->f_seekp);
200 }
201
202 static int
203 zfs_stat(struct open_file *f, struct stat *sb)
204 {
205 struct file *fp = (struct file *)f->f_fsdata;
206 znode_phys_t *zp = (znode_phys_t *) fp->f_dnode.dn_bonus;
207
208 /* only important stuff */
209 sb->st_mode = zp->zp_mode;
210 sb->st_uid = zp->zp_uid;
211 sb->st_gid = zp->zp_gid;
212 sb->st_size = zp->zp_size;
213
214 return (0);
215 }
216
217 static int
218 zfs_readdir(struct open_file *f, struct dirent *d)
219 {
220 spa_t *spa = (spa_t *) f->f_devdata;
221 struct file *fp = (struct file *)f->f_fsdata;
222 znode_phys_t *zp = (znode_phys_t *) fp->f_dnode.dn_bonus;
223 mzap_ent_phys_t mze;
224 size_t bsize = fp->f_dnode.dn_datablkszsec << SPA_MINBLOCKSHIFT;
225 int rc;
226
227 if ((zp->zp_mode >> 12) != 0x4) {
228 return (ENOTDIR);
229 }
230
231 /*
232 * If this is the first read, get the zap type.
233 */
234 if (fp->f_seekp == 0) {
235 rc = dnode_read(spa, &fp->f_dnode,
236 0, &fp->f_zap_type, sizeof(fp->f_zap_type));
237 if (rc)
238 return (rc);
239
240 if (fp->f_zap_type == ZBT_MICRO) {
241 fp->f_seekp = offsetof(mzap_phys_t, mz_chunk);
242 } else {
243 rc = dnode_read(spa, &fp->f_dnode,
244 offsetof(zap_phys_t, zap_num_leafs),
245 &fp->f_num_leafs,
246 sizeof(fp->f_num_leafs));
247 if (rc)
248 return (rc);
249
250 fp->f_seekp = bsize;
251 fp->f_zap_leaf = (zap_leaf_phys_t *)malloc(bsize);
252 rc = dnode_read(spa, &fp->f_dnode,
253 fp->f_seekp,
254 fp->f_zap_leaf,
255 bsize);
256 if (rc)
257 return (rc);
258 }
259 }
260
261 if (fp->f_zap_type == ZBT_MICRO) {
262 mzap_next:
263 if (fp->f_seekp >= bsize)
264 return (ENOENT);
265
266 rc = dnode_read(spa, &fp->f_dnode,
267 fp->f_seekp, &mze, sizeof(mze));
268 fp->f_seekp += sizeof(mze);
269
270 if (!mze.mze_name[0])
271 goto mzap_next;
272
273 d->d_fileno = ZFS_DIRENT_OBJ(mze.mze_value);
274 d->d_type = ZFS_DIRENT_TYPE(mze.mze_value);
275 strcpy(d->d_name, mze.mze_name);
276 d->d_namlen = strlen(d->d_name);
277 return (0);
278 } else {
279 zap_leaf_t zl;
280 zap_leaf_chunk_t *zc, *nc;
281 int chunk;
282 size_t namelen;
283 char *p;
284 uint64_t value;
285
286 /*
287 * Initialise this so we can use the ZAP size
288 * calculating macros.
289 */
290 zl.l_bs = ilog2(bsize);
291 zl.l_phys = fp->f_zap_leaf;
292
293 /*
294 * Figure out which chunk we are currently looking at
295 * and consider seeking to the next leaf. We use the
296 * low bits of f_seekp as a simple chunk index.
297 */
298 fzap_next:
299 chunk = fp->f_seekp & (bsize - 1);
300 if (chunk == ZAP_LEAF_NUMCHUNKS(&zl)) {
301 fp->f_seekp = (fp->f_seekp & ~(bsize - 1)) + bsize;
302 chunk = 0;
303
304 /*
305 * Check for EOF and read the new leaf.
306 */
307 if (fp->f_seekp >= bsize * fp->f_num_leafs)
308 return (ENOENT);
309
310 rc = dnode_read(spa, &fp->f_dnode,
311 fp->f_seekp,
312 fp->f_zap_leaf,
313 bsize);
314 if (rc)
315 return (rc);
316 }
317
318 zc = &ZAP_LEAF_CHUNK(&zl, chunk);
319 fp->f_seekp++;
320 if (zc->l_entry.le_type != ZAP_CHUNK_ENTRY)
321 goto fzap_next;
322
323 namelen = zc->l_entry.le_name_length;
324 if (namelen > sizeof(d->d_name))
325 namelen = sizeof(d->d_name);
326
327 /*
328 * Paste the name back together.
329 */
330 nc = &ZAP_LEAF_CHUNK(&zl, zc->l_entry.le_name_chunk);
331 p = d->d_name;
332 while (namelen > 0) {
333 int len;
334 len = namelen;
335 if (len > ZAP_LEAF_ARRAY_BYTES)
336 len = ZAP_LEAF_ARRAY_BYTES;
337 memcpy(p, nc->l_array.la_array, len);
338 p += len;
339 namelen -= len;
340 nc = &ZAP_LEAF_CHUNK(&zl, nc->l_array.la_next);
341 }
342 d->d_name[sizeof(d->d_name) - 1] = 0;
343
344 /*
345 * Assume the first eight bytes of the value are
346 * a uint64_t.
347 */
348 value = fzap_leaf_value(&zl, zc);
349
350 d->d_fileno = ZFS_DIRENT_OBJ(value);
351 d->d_type = ZFS_DIRENT_TYPE(value);
352 d->d_namlen = strlen(d->d_name);
353
354 return (0);
355 }
356 }
357
358 static int
359 vdev_read(vdev_t *vdev, void *priv, off_t offset, void *buf, size_t size)
360 {
361 int fd;
362
363 fd = (uintptr_t) priv;
364 lseek(fd, offset, SEEK_SET);
365 if (read(fd, buf, size) == size) {
366 return 0;
367 } else {
368 return (EIO);
369 }
370 }
371
372 /*
373 * Convert a pool guid to a 'unit number' suitable for use with zfs_dev_open.
374 */
375 int
376 zfs_guid_to_unit(uint64_t guid)
377 {
378 spa_t *spa;
379 int unit;
380
381 unit = 0;
382 STAILQ_FOREACH(spa, &zfs_pools, spa_link) {
383 if (spa->spa_guid == guid)
384 return unit;
385 unit++;
386 }
387 return (-1);
388 }
389
390 static int
391 zfs_dev_init(void)
392 {
393 char devname[512];
394 int unit, slice;
395 int fd;
396
397 /*
398 * Open all the disks we can find and see if we can reconstruct
399 * ZFS pools from them. Bogusly assumes that the disks are named
400 * diskN or diskNsM.
401 */
402 zfs_init();
403 for (unit = 0; unit < 32 /* XXX */; unit++) {
404 sprintf(devname, "disk%d:", unit);
405 fd = open(devname, O_RDONLY);
406 if (fd == -1)
407 continue;
408
409 /*
410 * If we find a vdev, the zfs code will eat the fd, otherwise
411 * we close it.
412 */
413 if (vdev_probe(vdev_read, (void*) (uintptr_t) fd, 0))
414 close(fd);
415
416 for (slice = 1; slice <= 4; slice++) {
417 sprintf(devname, "disk%dp%d:", unit, slice);
418 fd = open(devname, O_RDONLY);
419 if (fd == -1) {
420 sprintf(devname, "disk%ds%d:", unit, slice);
421 fd = open(devname, O_RDONLY);
422 if (fd == -1)
423 continue;
424 }
425 if (vdev_probe(vdev_read, (void*) (uintptr_t) fd, 0))
426 close(fd);
427 }
428 }
429
430 return (0);
431 }
432
433 /*
434 * Print information about ZFS pools
435 */
436 static void
437 zfs_dev_print(int verbose)
438 {
439 spa_t *spa;
440 char line[80];
441 int unit;
442
443 if (verbose) {
444 spa_all_status();
445 return;
446 }
447 unit = 0;
448 STAILQ_FOREACH(spa, &zfs_pools, spa_link) {
449 sprintf(line, " zfs%d: %s\n", unit, spa->spa_name);
450 pager_output(line);
451 unit++;
452 }
453 }
454
455 /*
456 * Attempt to open the pool described by (dev) for use by (f).
457 */
458 static int
459 zfs_dev_open(struct open_file *f, ...)
460 {
461 va_list args;
462 struct devdesc *dev;
463 int unit, i;
464 spa_t *spa;
465
466 va_start(args, f);
467 dev = va_arg(args, struct devdesc*);
468 va_end(args);
469
470 /*
471 * We mostly ignore the stuff that devopen sends us. For now,
472 * use the unit to find a pool - later we will override the
473 * devname parsing so that we can name a pool and a fs within
474 * the pool.
475 */
476 unit = dev->d_unit;
477
478 i = 0;
479 STAILQ_FOREACH(spa, &zfs_pools, spa_link) {
480 if (i == unit)
481 break;
482 i++;
483 }
484 if (!spa) {
485 return (ENXIO);
486 }
487
488 f->f_devdata = spa;
489 free(dev);
490 return (0);
491 }
492
493 static int
494 zfs_dev_close(struct open_file *f)
495 {
496
497 f->f_devdata = NULL;
498 return (0);
499 }
500
501 static int
502 zfs_dev_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
503 {
504
505 return (ENOSYS);
506 }
507
508 struct devsw zfs_dev = {
509 .dv_name = "zfs",
510 .dv_type = DEVT_ZFS,
511 .dv_init = zfs_dev_init,
512 .dv_strategy = zfs_dev_strategy,
513 .dv_open = zfs_dev_open,
514 .dv_close = zfs_dev_close,
515 .dv_ioctl = noioctl,
516 .dv_print = zfs_dev_print,
517 .dv_cleanup = NULL
518 };
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