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/10.1/sys/boot/zfs/zfs.c 241292 2012-10-06 19:42:50Z avg $
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/10.1/sys/boot/zfs/zfs.c 241292 2012-10-06 19:42:50Z avg $");
31
32 /*
33 * Stand-alone file reading package.
34 */
35
36 #include <sys/disk.h>
37 #include <sys/param.h>
38 #include <sys/time.h>
39 #include <sys/queue.h>
40 #include <part.h>
41 #include <stddef.h>
42 #include <stdarg.h>
43 #include <string.h>
44 #include <stand.h>
45 #include <bootstrap.h>
46
47 #include "libzfs.h"
48
49 #include "zfsimpl.c"
50
51 static int zfs_open(const char *path, struct open_file *f);
52 static int zfs_write(struct open_file *f, void *buf, size_t size, size_t *resid);
53 static int zfs_close(struct open_file *f);
54 static int zfs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
55 static off_t zfs_seek(struct open_file *f, off_t offset, int where);
56 static int zfs_stat(struct open_file *f, struct stat *sb);
57 static int zfs_readdir(struct open_file *f, struct dirent *d);
58
59 struct devsw zfs_dev;
60
61 struct fs_ops zfs_fsops = {
62 "zfs",
63 zfs_open,
64 zfs_close,
65 zfs_read,
66 zfs_write,
67 zfs_seek,
68 zfs_stat,
69 zfs_readdir
70 };
71
72 /*
73 * In-core open file.
74 */
75 struct file {
76 off_t f_seekp; /* seek pointer */
77 dnode_phys_t f_dnode;
78 uint64_t f_zap_type; /* zap type for readdir */
79 uint64_t f_num_leafs; /* number of fzap leaf blocks */
80 zap_leaf_phys_t *f_zap_leaf; /* zap leaf buffer */
81 };
82
83 /*
84 * Open a file.
85 */
86 static int
87 zfs_open(const char *upath, struct open_file *f)
88 {
89 struct zfsmount *mount = (struct zfsmount *)f->f_devdata;
90 struct file *fp;
91 int rc;
92
93 if (f->f_dev != &zfs_dev)
94 return (EINVAL);
95
96 /* allocate file system specific data structure */
97 fp = malloc(sizeof(struct file));
98 bzero(fp, sizeof(struct file));
99 f->f_fsdata = (void *)fp;
100
101 rc = zfs_lookup(mount, upath, &fp->f_dnode);
102 fp->f_seekp = 0;
103 if (rc) {
104 f->f_fsdata = NULL;
105 free(fp);
106 }
107 return (rc);
108 }
109
110 static int
111 zfs_close(struct open_file *f)
112 {
113 struct file *fp = (struct file *)f->f_fsdata;
114
115 dnode_cache_obj = 0;
116 f->f_fsdata = (void *)0;
117 if (fp == (struct file *)0)
118 return (0);
119
120 free(fp);
121 return (0);
122 }
123
124 /*
125 * Copy a portion of a file into kernel memory.
126 * Cross block boundaries when necessary.
127 */
128 static int
129 zfs_read(struct open_file *f, void *start, size_t size, size_t *resid /* out */)
130 {
131 const spa_t *spa = ((struct zfsmount *)f->f_devdata)->spa;
132 struct file *fp = (struct file *)f->f_fsdata;
133 struct stat sb;
134 size_t n;
135 int rc;
136
137 rc = zfs_stat(f, &sb);
138 if (rc)
139 return (rc);
140 n = size;
141 if (fp->f_seekp + n > sb.st_size)
142 n = sb.st_size - fp->f_seekp;
143
144 rc = dnode_read(spa, &fp->f_dnode, fp->f_seekp, start, n);
145 if (rc)
146 return (rc);
147
148 if (0) {
149 int i;
150 for (i = 0; i < n; i++)
151 putchar(((char*) start)[i]);
152 }
153 fp->f_seekp += n;
154 if (resid)
155 *resid = size - n;
156
157 return (0);
158 }
159
160 /*
161 * Don't be silly - the bootstrap has no business writing anything.
162 */
163 static int
164 zfs_write(struct open_file *f, void *start, size_t size, size_t *resid /* out */)
165 {
166
167 return (EROFS);
168 }
169
170 static off_t
171 zfs_seek(struct open_file *f, off_t offset, int where)
172 {
173 struct file *fp = (struct file *)f->f_fsdata;
174
175 switch (where) {
176 case SEEK_SET:
177 fp->f_seekp = offset;
178 break;
179 case SEEK_CUR:
180 fp->f_seekp += offset;
181 break;
182 case SEEK_END:
183 {
184 struct stat sb;
185 int error;
186
187 error = zfs_stat(f, &sb);
188 if (error != 0) {
189 errno = error;
190 return (-1);
191 }
192 fp->f_seekp = sb.st_size - offset;
193 break;
194 }
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 const spa_t *spa = ((struct zfsmount *)f->f_devdata)->spa;
206 struct file *fp = (struct file *)f->f_fsdata;
207
208 return (zfs_dnode_stat(spa, &fp->f_dnode, sb));
209 }
210
211 static int
212 zfs_readdir(struct open_file *f, struct dirent *d)
213 {
214 const spa_t *spa = ((struct zfsmount *)f->f_devdata)->spa;
215 struct file *fp = (struct file *)f->f_fsdata;
216 mzap_ent_phys_t mze;
217 struct stat sb;
218 size_t bsize = fp->f_dnode.dn_datablkszsec << SPA_MINBLOCKSHIFT;
219 int rc;
220
221 rc = zfs_stat(f, &sb);
222 if (rc)
223 return (rc);
224 if (!S_ISDIR(sb.st_mode))
225 return (ENOTDIR);
226
227 /*
228 * If this is the first read, get the zap type.
229 */
230 if (fp->f_seekp == 0) {
231 rc = dnode_read(spa, &fp->f_dnode,
232 0, &fp->f_zap_type, sizeof(fp->f_zap_type));
233 if (rc)
234 return (rc);
235
236 if (fp->f_zap_type == ZBT_MICRO) {
237 fp->f_seekp = offsetof(mzap_phys_t, mz_chunk);
238 } else {
239 rc = dnode_read(spa, &fp->f_dnode,
240 offsetof(zap_phys_t, zap_num_leafs),
241 &fp->f_num_leafs,
242 sizeof(fp->f_num_leafs));
243 if (rc)
244 return (rc);
245
246 fp->f_seekp = bsize;
247 fp->f_zap_leaf = (zap_leaf_phys_t *)malloc(bsize);
248 rc = dnode_read(spa, &fp->f_dnode,
249 fp->f_seekp,
250 fp->f_zap_leaf,
251 bsize);
252 if (rc)
253 return (rc);
254 }
255 }
256
257 if (fp->f_zap_type == ZBT_MICRO) {
258 mzap_next:
259 if (fp->f_seekp >= bsize)
260 return (ENOENT);
261
262 rc = dnode_read(spa, &fp->f_dnode,
263 fp->f_seekp, &mze, sizeof(mze));
264 if (rc)
265 return (rc);
266 fp->f_seekp += sizeof(mze);
267
268 if (!mze.mze_name[0])
269 goto mzap_next;
270
271 d->d_fileno = ZFS_DIRENT_OBJ(mze.mze_value);
272 d->d_type = ZFS_DIRENT_TYPE(mze.mze_value);
273 strcpy(d->d_name, mze.mze_name);
274 d->d_namlen = strlen(d->d_name);
275 return (0);
276 } else {
277 zap_leaf_t zl;
278 zap_leaf_chunk_t *zc, *nc;
279 int chunk;
280 size_t namelen;
281 char *p;
282 uint64_t value;
283
284 /*
285 * Initialise this so we can use the ZAP size
286 * calculating macros.
287 */
288 zl.l_bs = ilog2(bsize);
289 zl.l_phys = fp->f_zap_leaf;
290
291 /*
292 * Figure out which chunk we are currently looking at
293 * and consider seeking to the next leaf. We use the
294 * low bits of f_seekp as a simple chunk index.
295 */
296 fzap_next:
297 chunk = fp->f_seekp & (bsize - 1);
298 if (chunk == ZAP_LEAF_NUMCHUNKS(&zl)) {
299 fp->f_seekp = (fp->f_seekp & ~(bsize - 1)) + bsize;
300 chunk = 0;
301
302 /*
303 * Check for EOF and read the new leaf.
304 */
305 if (fp->f_seekp >= bsize * fp->f_num_leafs)
306 return (ENOENT);
307
308 rc = dnode_read(spa, &fp->f_dnode,
309 fp->f_seekp,
310 fp->f_zap_leaf,
311 bsize);
312 if (rc)
313 return (rc);
314 }
315
316 zc = &ZAP_LEAF_CHUNK(&zl, chunk);
317 fp->f_seekp++;
318 if (zc->l_entry.le_type != ZAP_CHUNK_ENTRY)
319 goto fzap_next;
320
321 namelen = zc->l_entry.le_name_numints;
322 if (namelen > sizeof(d->d_name))
323 namelen = sizeof(d->d_name);
324
325 /*
326 * Paste the name back together.
327 */
328 nc = &ZAP_LEAF_CHUNK(&zl, zc->l_entry.le_name_chunk);
329 p = d->d_name;
330 while (namelen > 0) {
331 int len;
332 len = namelen;
333 if (len > ZAP_LEAF_ARRAY_BYTES)
334 len = ZAP_LEAF_ARRAY_BYTES;
335 memcpy(p, nc->l_array.la_array, len);
336 p += len;
337 namelen -= len;
338 nc = &ZAP_LEAF_CHUNK(&zl, nc->l_array.la_next);
339 }
340 d->d_name[sizeof(d->d_name) - 1] = 0;
341
342 /*
343 * Assume the first eight bytes of the value are
344 * a uint64_t.
345 */
346 value = fzap_leaf_value(&zl, zc);
347
348 d->d_fileno = ZFS_DIRENT_OBJ(value);
349 d->d_type = ZFS_DIRENT_TYPE(value);
350 d->d_namlen = strlen(d->d_name);
351
352 return (0);
353 }
354 }
355
356 static int
357 vdev_read(vdev_t *vdev, void *priv, off_t offset, void *buf, size_t size)
358 {
359 int fd;
360
361 fd = (uintptr_t) priv;
362 lseek(fd, offset, SEEK_SET);
363 if (read(fd, buf, size) == size) {
364 return 0;
365 } else {
366 return (EIO);
367 }
368 }
369
370 static int
371 zfs_dev_init(void)
372 {
373 spa_t *spa;
374 spa_t *next;
375 spa_t *prev;
376
377 zfs_init();
378 if (archsw.arch_zfs_probe == NULL)
379 return (ENXIO);
380 archsw.arch_zfs_probe();
381
382 prev = NULL;
383 spa = STAILQ_FIRST(&zfs_pools);
384 while (spa != NULL) {
385 next = STAILQ_NEXT(spa, spa_link);
386 if (zfs_spa_init(spa)) {
387 if (prev == NULL)
388 STAILQ_REMOVE_HEAD(&zfs_pools, spa_link);
389 else
390 STAILQ_REMOVE_AFTER(&zfs_pools, prev, spa_link);
391 } else
392 prev = spa;
393 spa = next;
394 }
395 return (0);
396 }
397
398 struct zfs_probe_args {
399 int fd;
400 const char *devname;
401 uint64_t *pool_guid;
402 uint16_t secsz;
403 };
404
405 static int
406 zfs_diskread(void *arg, void *buf, size_t blocks, off_t offset)
407 {
408 struct zfs_probe_args *ppa;
409
410 ppa = (struct zfs_probe_args *)arg;
411 return (vdev_read(NULL, (void *)(uintptr_t)ppa->fd,
412 offset * ppa->secsz, buf, blocks * ppa->secsz));
413 }
414
415 static int
416 zfs_probe(int fd, uint64_t *pool_guid)
417 {
418 spa_t *spa;
419 int ret;
420
421 ret = vdev_probe(vdev_read, (void *)(uintptr_t)fd, &spa);
422 if (ret == 0 && pool_guid != NULL)
423 *pool_guid = spa->spa_guid;
424 return (ret);
425 }
426
427 static void
428 zfs_probe_partition(void *arg, const char *partname,
429 const struct ptable_entry *part)
430 {
431 struct zfs_probe_args *ppa, pa;
432 struct ptable *table;
433 char devname[32];
434 int ret;
435
436 /* Probe only freebsd-zfs and freebsd partitions */
437 if (part->type != PART_FREEBSD &&
438 part->type != PART_FREEBSD_ZFS)
439 return;
440
441 ppa = (struct zfs_probe_args *)arg;
442 strncpy(devname, ppa->devname, strlen(ppa->devname) - 1);
443 devname[strlen(ppa->devname) - 1] = '\0';
444 sprintf(devname, "%s%s:", devname, partname);
445 pa.fd = open(devname, O_RDONLY);
446 if (pa.fd == -1)
447 return;
448 ret = zfs_probe(pa.fd, ppa->pool_guid);
449 if (ret == 0)
450 return;
451 /* Do we have BSD label here? */
452 if (part->type == PART_FREEBSD) {
453 pa.devname = devname;
454 pa.pool_guid = ppa->pool_guid;
455 pa.secsz = ppa->secsz;
456 table = ptable_open(&pa, part->end - part->start + 1,
457 ppa->secsz, zfs_diskread);
458 if (table != NULL) {
459 ptable_iterate(table, &pa, zfs_probe_partition);
460 ptable_close(table);
461 }
462 }
463 close(pa.fd);
464 }
465
466 int
467 zfs_probe_dev(const char *devname, uint64_t *pool_guid)
468 {
469 struct ptable *table;
470 struct zfs_probe_args pa;
471 off_t mediasz;
472 int ret;
473
474 pa.fd = open(devname, O_RDONLY);
475 if (pa.fd == -1)
476 return (ENXIO);
477 /* Probe the whole disk */
478 ret = zfs_probe(pa.fd, pool_guid);
479 if (ret == 0)
480 return (0);
481 /* Probe each partition */
482 ret = ioctl(pa.fd, DIOCGMEDIASIZE, &mediasz);
483 if (ret == 0)
484 ret = ioctl(pa.fd, DIOCGSECTORSIZE, &pa.secsz);
485 if (ret == 0) {
486 pa.devname = devname;
487 pa.pool_guid = pool_guid;
488 table = ptable_open(&pa, mediasz / pa.secsz, pa.secsz,
489 zfs_diskread);
490 if (table != NULL) {
491 ptable_iterate(table, &pa, zfs_probe_partition);
492 ptable_close(table);
493 }
494 }
495 close(pa.fd);
496 return (0);
497 }
498
499 /*
500 * Print information about ZFS pools
501 */
502 static void
503 zfs_dev_print(int verbose)
504 {
505 spa_t *spa;
506 char line[80];
507
508 if (verbose) {
509 spa_all_status();
510 return;
511 }
512 STAILQ_FOREACH(spa, &zfs_pools, spa_link) {
513 sprintf(line, " zfs:%s\n", spa->spa_name);
514 pager_output(line);
515 }
516 }
517
518 /*
519 * Attempt to open the pool described by (dev) for use by (f).
520 */
521 static int
522 zfs_dev_open(struct open_file *f, ...)
523 {
524 va_list args;
525 struct zfs_devdesc *dev;
526 struct zfsmount *mount;
527 spa_t *spa;
528 int rv;
529
530 va_start(args, f);
531 dev = va_arg(args, struct zfs_devdesc *);
532 va_end(args);
533
534 if (dev->pool_guid == 0)
535 spa = STAILQ_FIRST(&zfs_pools);
536 else
537 spa = spa_find_by_guid(dev->pool_guid);
538 if (!spa)
539 return (ENXIO);
540 mount = malloc(sizeof(*mount));
541 rv = zfs_mount(spa, dev->root_guid, mount);
542 if (rv != 0) {
543 free(mount);
544 return (rv);
545 }
546 if (mount->objset.os_type != DMU_OST_ZFS) {
547 printf("Unexpected object set type %ju\n",
548 (uintmax_t)mount->objset.os_type);
549 free(mount);
550 return (EIO);
551 }
552 f->f_devdata = mount;
553 free(dev);
554 return (0);
555 }
556
557 static int
558 zfs_dev_close(struct open_file *f)
559 {
560
561 free(f->f_devdata);
562 f->f_devdata = NULL;
563 return (0);
564 }
565
566 static int
567 zfs_dev_strategy(void *devdata, int rw, daddr_t dblk, size_t size, char *buf, size_t *rsize)
568 {
569
570 return (ENOSYS);
571 }
572
573 struct devsw zfs_dev = {
574 .dv_name = "zfs",
575 .dv_type = DEVT_ZFS,
576 .dv_init = zfs_dev_init,
577 .dv_strategy = zfs_dev_strategy,
578 .dv_open = zfs_dev_open,
579 .dv_close = zfs_dev_close,
580 .dv_ioctl = noioctl,
581 .dv_print = zfs_dev_print,
582 .dv_cleanup = NULL
583 };
584
585 int
586 zfs_parsedev(struct zfs_devdesc *dev, const char *devspec, const char **path)
587 {
588 static char rootname[ZFS_MAXNAMELEN];
589 static char poolname[ZFS_MAXNAMELEN];
590 spa_t *spa;
591 const char *end;
592 const char *np;
593 const char *sep;
594 int rv;
595
596 np = devspec;
597 if (*np != ':')
598 return (EINVAL);
599 np++;
600 end = strchr(np, ':');
601 if (end == NULL)
602 return (EINVAL);
603 sep = strchr(np, '/');
604 if (sep == NULL || sep >= end)
605 sep = end;
606 memcpy(poolname, np, sep - np);
607 poolname[sep - np] = '\0';
608 if (sep < end) {
609 sep++;
610 memcpy(rootname, sep, end - sep);
611 rootname[end - sep] = '\0';
612 }
613 else
614 rootname[0] = '\0';
615
616 spa = spa_find_by_name(poolname);
617 if (!spa)
618 return (ENXIO);
619 dev->pool_guid = spa->spa_guid;
620 rv = zfs_lookup_dataset(spa, rootname, &dev->root_guid);
621 if (rv != 0)
622 return (rv);
623 if (path != NULL)
624 *path = (*end == '\0') ? end : end + 1;
625 dev->d_dev = &zfs_dev;
626 dev->d_type = zfs_dev.dv_type;
627 return (0);
628 }
629
630 char *
631 zfs_fmtdev(void *vdev)
632 {
633 static char rootname[ZFS_MAXNAMELEN];
634 static char buf[2 * ZFS_MAXNAMELEN + 8];
635 struct zfs_devdesc *dev = (struct zfs_devdesc *)vdev;
636 spa_t *spa;
637
638 buf[0] = '\0';
639 if (dev->d_type != DEVT_ZFS)
640 return (buf);
641
642 if (dev->pool_guid == 0) {
643 spa = STAILQ_FIRST(&zfs_pools);
644 dev->pool_guid = spa->spa_guid;
645 } else
646 spa = spa_find_by_guid(dev->pool_guid);
647 if (spa == NULL) {
648 printf("ZFS: can't find pool by guid\n");
649 return (buf);
650 }
651 if (dev->root_guid == 0 && zfs_get_root(spa, &dev->root_guid)) {
652 printf("ZFS: can't find root filesystem\n");
653 return (buf);
654 }
655 if (zfs_rlookup(spa, dev->root_guid, rootname)) {
656 printf("ZFS: can't find filesystem by guid\n");
657 return (buf);
658 }
659
660 if (rootname[0] == '\0')
661 sprintf(buf, "%s:%s:", dev->d_dev->dv_name, spa->spa_name);
662 else
663 sprintf(buf, "%s:%s/%s:", dev->d_dev->dv_name, spa->spa_name,
664 rootname);
665 return (buf);
666 }
667
668 int
669 zfs_list(const char *name)
670 {
671 static char poolname[ZFS_MAXNAMELEN];
672 uint64_t objid;
673 spa_t *spa;
674 const char *dsname;
675 int len;
676 int rv;
677
678 len = strlen(name);
679 dsname = strchr(name, '/');
680 if (dsname != NULL) {
681 len = dsname - name;
682 dsname++;
683 } else
684 dsname = "";
685 memcpy(poolname, name, len);
686 poolname[len] = '\0';
687
688 spa = spa_find_by_name(poolname);
689 if (!spa)
690 return (ENXIO);
691 rv = zfs_lookup_dataset(spa, dsname, &objid);
692 if (rv != 0)
693 return (rv);
694 rv = zfs_list_dataset(spa, objid);
695 return (rv);
696 }
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