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[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / btrfs / send.c
1 /*
2 * Copyright (C) 2012 Alexander Block. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/bsearch.h>
20 #include <linux/fs.h>
21 #include <linux/file.h>
22 #include <linux/sort.h>
23 #include <linux/mount.h>
24 #include <linux/xattr.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/radix-tree.h>
27 #include <linux/crc32c.h>
28 #include <linux/vmalloc.h>
29
30 #include "send.h"
31 #include "backref.h"
32 #include "locking.h"
33 #include "disk-io.h"
34 #include "btrfs_inode.h"
35 #include "transaction.h"
36
37 static int g_verbose = 0;
38
39 #define verbose_printk(...) if (g_verbose) printk(__VA_ARGS__)
40
41 /*
42 * A fs_path is a helper to dynamically build path names with unknown size.
43 * It reallocates the internal buffer on demand.
44 * It allows fast adding of path elements on the right side (normal path) and
45 * fast adding to the left side (reversed path). A reversed path can also be
46 * unreversed if needed.
47 */
48 struct fs_path {
49 union {
50 struct {
51 char *start;
52 char *end;
53 char *prepared;
54
55 char *buf;
56 int buf_len;
57 int reversed:1;
58 int virtual_mem:1;
59 char inline_buf[];
60 };
61 char pad[PAGE_SIZE];
62 };
63 };
64 #define FS_PATH_INLINE_SIZE \
65 (sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
66
67
68 /* reused for each extent */
69 struct clone_root {
70 struct btrfs_root *root;
71 u64 ino;
72 u64 offset;
73
74 u64 found_refs;
75 };
76
77 #define SEND_CTX_MAX_NAME_CACHE_SIZE 128
78 #define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
79
80 struct send_ctx {
81 struct file *send_filp;
82 loff_t send_off;
83 char *send_buf;
84 u32 send_size;
85 u32 send_max_size;
86 u64 total_send_size;
87 u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
88
89 struct vfsmount *mnt;
90
91 struct btrfs_root *send_root;
92 struct btrfs_root *parent_root;
93 struct clone_root *clone_roots;
94 int clone_roots_cnt;
95
96 /* current state of the compare_tree call */
97 struct btrfs_path *left_path;
98 struct btrfs_path *right_path;
99 struct btrfs_key *cmp_key;
100
101 /*
102 * infos of the currently processed inode. In case of deleted inodes,
103 * these are the values from the deleted inode.
104 */
105 u64 cur_ino;
106 u64 cur_inode_gen;
107 int cur_inode_new;
108 int cur_inode_new_gen;
109 int cur_inode_deleted;
110 u64 cur_inode_size;
111 u64 cur_inode_mode;
112
113 u64 send_progress;
114
115 struct list_head new_refs;
116 struct list_head deleted_refs;
117
118 struct radix_tree_root name_cache;
119 struct list_head name_cache_list;
120 int name_cache_size;
121
122 struct file *cur_inode_filp;
123 char *read_buf;
124 };
125
126 struct name_cache_entry {
127 struct list_head list;
128 /*
129 * radix_tree has only 32bit entries but we need to handle 64bit inums.
130 * We use the lower 32bit of the 64bit inum to store it in the tree. If
131 * more then one inum would fall into the same entry, we use radix_list
132 * to store the additional entries. radix_list is also used to store
133 * entries where two entries have the same inum but different
134 * generations.
135 */
136 struct list_head radix_list;
137 u64 ino;
138 u64 gen;
139 u64 parent_ino;
140 u64 parent_gen;
141 int ret;
142 int need_later_update;
143 int name_len;
144 char name[];
145 };
146
147 static void fs_path_reset(struct fs_path *p)
148 {
149 if (p->reversed) {
150 p->start = p->buf + p->buf_len - 1;
151 p->end = p->start;
152 *p->start = 0;
153 } else {
154 p->start = p->buf;
155 p->end = p->start;
156 *p->start = 0;
157 }
158 }
159
160 static struct fs_path *fs_path_alloc(struct send_ctx *sctx)
161 {
162 struct fs_path *p;
163
164 p = kmalloc(sizeof(*p), GFP_NOFS);
165 if (!p)
166 return NULL;
167 p->reversed = 0;
168 p->virtual_mem = 0;
169 p->buf = p->inline_buf;
170 p->buf_len = FS_PATH_INLINE_SIZE;
171 fs_path_reset(p);
172 return p;
173 }
174
175 static struct fs_path *fs_path_alloc_reversed(struct send_ctx *sctx)
176 {
177 struct fs_path *p;
178
179 p = fs_path_alloc(sctx);
180 if (!p)
181 return NULL;
182 p->reversed = 1;
183 fs_path_reset(p);
184 return p;
185 }
186
187 static void fs_path_free(struct send_ctx *sctx, struct fs_path *p)
188 {
189 if (!p)
190 return;
191 if (p->buf != p->inline_buf) {
192 if (p->virtual_mem)
193 vfree(p->buf);
194 else
195 kfree(p->buf);
196 }
197 kfree(p);
198 }
199
200 static int fs_path_len(struct fs_path *p)
201 {
202 return p->end - p->start;
203 }
204
205 static int fs_path_ensure_buf(struct fs_path *p, int len)
206 {
207 char *tmp_buf;
208 int path_len;
209 int old_buf_len;
210
211 len++;
212
213 if (p->buf_len >= len)
214 return 0;
215
216 path_len = p->end - p->start;
217 old_buf_len = p->buf_len;
218 len = PAGE_ALIGN(len);
219
220 if (p->buf == p->inline_buf) {
221 tmp_buf = kmalloc(len, GFP_NOFS);
222 if (!tmp_buf) {
223 tmp_buf = vmalloc(len);
224 if (!tmp_buf)
225 return -ENOMEM;
226 p->virtual_mem = 1;
227 }
228 memcpy(tmp_buf, p->buf, p->buf_len);
229 p->buf = tmp_buf;
230 p->buf_len = len;
231 } else {
232 if (p->virtual_mem) {
233 tmp_buf = vmalloc(len);
234 if (!tmp_buf)
235 return -ENOMEM;
236 memcpy(tmp_buf, p->buf, p->buf_len);
237 vfree(p->buf);
238 } else {
239 tmp_buf = krealloc(p->buf, len, GFP_NOFS);
240 if (!tmp_buf) {
241 tmp_buf = vmalloc(len);
242 if (!tmp_buf)
243 return -ENOMEM;
244 memcpy(tmp_buf, p->buf, p->buf_len);
245 kfree(p->buf);
246 p->virtual_mem = 1;
247 }
248 }
249 p->buf = tmp_buf;
250 p->buf_len = len;
251 }
252 if (p->reversed) {
253 tmp_buf = p->buf + old_buf_len - path_len - 1;
254 p->end = p->buf + p->buf_len - 1;
255 p->start = p->end - path_len;
256 memmove(p->start, tmp_buf, path_len + 1);
257 } else {
258 p->start = p->buf;
259 p->end = p->start + path_len;
260 }
261 return 0;
262 }
263
264 static int fs_path_prepare_for_add(struct fs_path *p, int name_len)
265 {
266 int ret;
267 int new_len;
268
269 new_len = p->end - p->start + name_len;
270 if (p->start != p->end)
271 new_len++;
272 ret = fs_path_ensure_buf(p, new_len);
273 if (ret < 0)
274 goto out;
275
276 if (p->reversed) {
277 if (p->start != p->end)
278 *--p->start = '/';
279 p->start -= name_len;
280 p->prepared = p->start;
281 } else {
282 if (p->start != p->end)
283 *p->end++ = '/';
284 p->prepared = p->end;
285 p->end += name_len;
286 *p->end = 0;
287 }
288
289 out:
290 return ret;
291 }
292
293 static int fs_path_add(struct fs_path *p, const char *name, int name_len)
294 {
295 int ret;
296
297 ret = fs_path_prepare_for_add(p, name_len);
298 if (ret < 0)
299 goto out;
300 memcpy(p->prepared, name, name_len);
301 p->prepared = NULL;
302
303 out:
304 return ret;
305 }
306
307 static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
308 {
309 int ret;
310
311 ret = fs_path_prepare_for_add(p, p2->end - p2->start);
312 if (ret < 0)
313 goto out;
314 memcpy(p->prepared, p2->start, p2->end - p2->start);
315 p->prepared = NULL;
316
317 out:
318 return ret;
319 }
320
321 static int fs_path_add_from_extent_buffer(struct fs_path *p,
322 struct extent_buffer *eb,
323 unsigned long off, int len)
324 {
325 int ret;
326
327 ret = fs_path_prepare_for_add(p, len);
328 if (ret < 0)
329 goto out;
330
331 read_extent_buffer(eb, p->prepared, off, len);
332 p->prepared = NULL;
333
334 out:
335 return ret;
336 }
337
338 #if 0
339 static void fs_path_remove(struct fs_path *p)
340 {
341 BUG_ON(p->reversed);
342 while (p->start != p->end && *p->end != '/')
343 p->end--;
344 *p->end = 0;
345 }
346 #endif
347
348 static int fs_path_copy(struct fs_path *p, struct fs_path *from)
349 {
350 int ret;
351
352 p->reversed = from->reversed;
353 fs_path_reset(p);
354
355 ret = fs_path_add_path(p, from);
356
357 return ret;
358 }
359
360
361 static void fs_path_unreverse(struct fs_path *p)
362 {
363 char *tmp;
364 int len;
365
366 if (!p->reversed)
367 return;
368
369 tmp = p->start;
370 len = p->end - p->start;
371 p->start = p->buf;
372 p->end = p->start + len;
373 memmove(p->start, tmp, len + 1);
374 p->reversed = 0;
375 }
376
377 static struct btrfs_path *alloc_path_for_send(void)
378 {
379 struct btrfs_path *path;
380
381 path = btrfs_alloc_path();
382 if (!path)
383 return NULL;
384 path->search_commit_root = 1;
385 path->skip_locking = 1;
386 return path;
387 }
388
389 int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
390 {
391 int ret;
392 mm_segment_t old_fs;
393 u32 pos = 0;
394
395 old_fs = get_fs();
396 set_fs(KERNEL_DS);
397
398 while (pos < len) {
399 ret = vfs_write(filp, (char *)buf + pos, len - pos, off);
400 /* TODO handle that correctly */
401 /*if (ret == -ERESTARTSYS) {
402 continue;
403 }*/
404 if (ret < 0)
405 goto out;
406 if (ret == 0) {
407 ret = -EIO;
408 goto out;
409 }
410 pos += ret;
411 }
412
413 ret = 0;
414
415 out:
416 set_fs(old_fs);
417 return ret;
418 }
419
420 static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
421 {
422 struct btrfs_tlv_header *hdr;
423 int total_len = sizeof(*hdr) + len;
424 int left = sctx->send_max_size - sctx->send_size;
425
426 if (unlikely(left < total_len))
427 return -EOVERFLOW;
428
429 hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
430 hdr->tlv_type = cpu_to_le16(attr);
431 hdr->tlv_len = cpu_to_le16(len);
432 memcpy(hdr + 1, data, len);
433 sctx->send_size += total_len;
434
435 return 0;
436 }
437
438 #if 0
439 static int tlv_put_u8(struct send_ctx *sctx, u16 attr, u8 value)
440 {
441 return tlv_put(sctx, attr, &value, sizeof(value));
442 }
443
444 static int tlv_put_u16(struct send_ctx *sctx, u16 attr, u16 value)
445 {
446 __le16 tmp = cpu_to_le16(value);
447 return tlv_put(sctx, attr, &tmp, sizeof(tmp));
448 }
449
450 static int tlv_put_u32(struct send_ctx *sctx, u16 attr, u32 value)
451 {
452 __le32 tmp = cpu_to_le32(value);
453 return tlv_put(sctx, attr, &tmp, sizeof(tmp));
454 }
455 #endif
456
457 static int tlv_put_u64(struct send_ctx *sctx, u16 attr, u64 value)
458 {
459 __le64 tmp = cpu_to_le64(value);
460 return tlv_put(sctx, attr, &tmp, sizeof(tmp));
461 }
462
463 static int tlv_put_string(struct send_ctx *sctx, u16 attr,
464 const char *str, int len)
465 {
466 if (len == -1)
467 len = strlen(str);
468 return tlv_put(sctx, attr, str, len);
469 }
470
471 static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
472 const u8 *uuid)
473 {
474 return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
475 }
476
477 #if 0
478 static int tlv_put_timespec(struct send_ctx *sctx, u16 attr,
479 struct timespec *ts)
480 {
481 struct btrfs_timespec bts;
482 bts.sec = cpu_to_le64(ts->tv_sec);
483 bts.nsec = cpu_to_le32(ts->tv_nsec);
484 return tlv_put(sctx, attr, &bts, sizeof(bts));
485 }
486 #endif
487
488 static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
489 struct extent_buffer *eb,
490 struct btrfs_timespec *ts)
491 {
492 struct btrfs_timespec bts;
493 read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
494 return tlv_put(sctx, attr, &bts, sizeof(bts));
495 }
496
497
498 #define TLV_PUT(sctx, attrtype, attrlen, data) \
499 do { \
500 ret = tlv_put(sctx, attrtype, attrlen, data); \
501 if (ret < 0) \
502 goto tlv_put_failure; \
503 } while (0)
504
505 #define TLV_PUT_INT(sctx, attrtype, bits, value) \
506 do { \
507 ret = tlv_put_u##bits(sctx, attrtype, value); \
508 if (ret < 0) \
509 goto tlv_put_failure; \
510 } while (0)
511
512 #define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
513 #define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
514 #define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
515 #define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
516 #define TLV_PUT_STRING(sctx, attrtype, str, len) \
517 do { \
518 ret = tlv_put_string(sctx, attrtype, str, len); \
519 if (ret < 0) \
520 goto tlv_put_failure; \
521 } while (0)
522 #define TLV_PUT_PATH(sctx, attrtype, p) \
523 do { \
524 ret = tlv_put_string(sctx, attrtype, p->start, \
525 p->end - p->start); \
526 if (ret < 0) \
527 goto tlv_put_failure; \
528 } while(0)
529 #define TLV_PUT_UUID(sctx, attrtype, uuid) \
530 do { \
531 ret = tlv_put_uuid(sctx, attrtype, uuid); \
532 if (ret < 0) \
533 goto tlv_put_failure; \
534 } while (0)
535 #define TLV_PUT_TIMESPEC(sctx, attrtype, ts) \
536 do { \
537 ret = tlv_put_timespec(sctx, attrtype, ts); \
538 if (ret < 0) \
539 goto tlv_put_failure; \
540 } while (0)
541 #define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
542 do { \
543 ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
544 if (ret < 0) \
545 goto tlv_put_failure; \
546 } while (0)
547
548 static int send_header(struct send_ctx *sctx)
549 {
550 struct btrfs_stream_header hdr;
551
552 strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
553 hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
554
555 return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
556 &sctx->send_off);
557 }
558
559 /*
560 * For each command/item we want to send to userspace, we call this function.
561 */
562 static int begin_cmd(struct send_ctx *sctx, int cmd)
563 {
564 struct btrfs_cmd_header *hdr;
565
566 if (!sctx->send_buf) {
567 WARN_ON(1);
568 return -EINVAL;
569 }
570
571 BUG_ON(sctx->send_size);
572
573 sctx->send_size += sizeof(*hdr);
574 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
575 hdr->cmd = cpu_to_le16(cmd);
576
577 return 0;
578 }
579
580 static int send_cmd(struct send_ctx *sctx)
581 {
582 int ret;
583 struct btrfs_cmd_header *hdr;
584 u32 crc;
585
586 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
587 hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
588 hdr->crc = 0;
589
590 crc = crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
591 hdr->crc = cpu_to_le32(crc);
592
593 ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
594 &sctx->send_off);
595
596 sctx->total_send_size += sctx->send_size;
597 sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
598 sctx->send_size = 0;
599
600 return ret;
601 }
602
603 /*
604 * Sends a move instruction to user space
605 */
606 static int send_rename(struct send_ctx *sctx,
607 struct fs_path *from, struct fs_path *to)
608 {
609 int ret;
610
611 verbose_printk("btrfs: send_rename %s -> %s\n", from->start, to->start);
612
613 ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
614 if (ret < 0)
615 goto out;
616
617 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
618 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
619
620 ret = send_cmd(sctx);
621
622 tlv_put_failure:
623 out:
624 return ret;
625 }
626
627 /*
628 * Sends a link instruction to user space
629 */
630 static int send_link(struct send_ctx *sctx,
631 struct fs_path *path, struct fs_path *lnk)
632 {
633 int ret;
634
635 verbose_printk("btrfs: send_link %s -> %s\n", path->start, lnk->start);
636
637 ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
638 if (ret < 0)
639 goto out;
640
641 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
642 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
643
644 ret = send_cmd(sctx);
645
646 tlv_put_failure:
647 out:
648 return ret;
649 }
650
651 /*
652 * Sends an unlink instruction to user space
653 */
654 static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
655 {
656 int ret;
657
658 verbose_printk("btrfs: send_unlink %s\n", path->start);
659
660 ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
661 if (ret < 0)
662 goto out;
663
664 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
665
666 ret = send_cmd(sctx);
667
668 tlv_put_failure:
669 out:
670 return ret;
671 }
672
673 /*
674 * Sends a rmdir instruction to user space
675 */
676 static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
677 {
678 int ret;
679
680 verbose_printk("btrfs: send_rmdir %s\n", path->start);
681
682 ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
683 if (ret < 0)
684 goto out;
685
686 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
687
688 ret = send_cmd(sctx);
689
690 tlv_put_failure:
691 out:
692 return ret;
693 }
694
695 /*
696 * Helper function to retrieve some fields from an inode item.
697 */
698 static int get_inode_info(struct btrfs_root *root,
699 u64 ino, u64 *size, u64 *gen,
700 u64 *mode, u64 *uid, u64 *gid,
701 u64 *rdev)
702 {
703 int ret;
704 struct btrfs_inode_item *ii;
705 struct btrfs_key key;
706 struct btrfs_path *path;
707
708 path = alloc_path_for_send();
709 if (!path)
710 return -ENOMEM;
711
712 key.objectid = ino;
713 key.type = BTRFS_INODE_ITEM_KEY;
714 key.offset = 0;
715 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
716 if (ret < 0)
717 goto out;
718 if (ret) {
719 ret = -ENOENT;
720 goto out;
721 }
722
723 ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
724 struct btrfs_inode_item);
725 if (size)
726 *size = btrfs_inode_size(path->nodes[0], ii);
727 if (gen)
728 *gen = btrfs_inode_generation(path->nodes[0], ii);
729 if (mode)
730 *mode = btrfs_inode_mode(path->nodes[0], ii);
731 if (uid)
732 *uid = btrfs_inode_uid(path->nodes[0], ii);
733 if (gid)
734 *gid = btrfs_inode_gid(path->nodes[0], ii);
735 if (rdev)
736 *rdev = btrfs_inode_rdev(path->nodes[0], ii);
737
738 out:
739 btrfs_free_path(path);
740 return ret;
741 }
742
743 typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
744 struct fs_path *p,
745 void *ctx);
746
747 /*
748 * Helper function to iterate the entries in ONE btrfs_inode_ref or
749 * btrfs_inode_extref.
750 * The iterate callback may return a non zero value to stop iteration. This can
751 * be a negative value for error codes or 1 to simply stop it.
752 *
753 * path must point to the INODE_REF or INODE_EXTREF when called.
754 */
755 static int iterate_inode_ref(struct send_ctx *sctx,
756 struct btrfs_root *root, struct btrfs_path *path,
757 struct btrfs_key *found_key, int resolve,
758 iterate_inode_ref_t iterate, void *ctx)
759 {
760 struct extent_buffer *eb = path->nodes[0];
761 struct btrfs_item *item;
762 struct btrfs_inode_ref *iref;
763 struct btrfs_inode_extref *extref;
764 struct btrfs_path *tmp_path;
765 struct fs_path *p;
766 u32 cur = 0;
767 u32 total;
768 int slot = path->slots[0];
769 u32 name_len;
770 char *start;
771 int ret = 0;
772 int num = 0;
773 int index;
774 u64 dir;
775 unsigned long name_off;
776 unsigned long elem_size;
777 unsigned long ptr;
778
779 p = fs_path_alloc_reversed(sctx);
780 if (!p)
781 return -ENOMEM;
782
783 tmp_path = alloc_path_for_send();
784 if (!tmp_path) {
785 fs_path_free(sctx, p);
786 return -ENOMEM;
787 }
788
789
790 if (found_key->type == BTRFS_INODE_REF_KEY) {
791 ptr = (unsigned long)btrfs_item_ptr(eb, slot,
792 struct btrfs_inode_ref);
793 item = btrfs_item_nr(eb, slot);
794 total = btrfs_item_size(eb, item);
795 elem_size = sizeof(*iref);
796 } else {
797 ptr = btrfs_item_ptr_offset(eb, slot);
798 total = btrfs_item_size_nr(eb, slot);
799 elem_size = sizeof(*extref);
800 }
801
802 while (cur < total) {
803 fs_path_reset(p);
804
805 if (found_key->type == BTRFS_INODE_REF_KEY) {
806 iref = (struct btrfs_inode_ref *)(ptr + cur);
807 name_len = btrfs_inode_ref_name_len(eb, iref);
808 name_off = (unsigned long)(iref + 1);
809 index = btrfs_inode_ref_index(eb, iref);
810 dir = found_key->offset;
811 } else {
812 extref = (struct btrfs_inode_extref *)(ptr + cur);
813 name_len = btrfs_inode_extref_name_len(eb, extref);
814 name_off = (unsigned long)&extref->name;
815 index = btrfs_inode_extref_index(eb, extref);
816 dir = btrfs_inode_extref_parent(eb, extref);
817 }
818
819 if (resolve) {
820 start = btrfs_ref_to_path(root, tmp_path, name_len,
821 name_off, eb, dir,
822 p->buf, p->buf_len);
823 if (IS_ERR(start)) {
824 ret = PTR_ERR(start);
825 goto out;
826 }
827 if (start < p->buf) {
828 /* overflow , try again with larger buffer */
829 ret = fs_path_ensure_buf(p,
830 p->buf_len + p->buf - start);
831 if (ret < 0)
832 goto out;
833 start = btrfs_ref_to_path(root, tmp_path,
834 name_len, name_off,
835 eb, dir,
836 p->buf, p->buf_len);
837 if (IS_ERR(start)) {
838 ret = PTR_ERR(start);
839 goto out;
840 }
841 BUG_ON(start < p->buf);
842 }
843 p->start = start;
844 } else {
845 ret = fs_path_add_from_extent_buffer(p, eb, name_off,
846 name_len);
847 if (ret < 0)
848 goto out;
849 }
850
851 cur += elem_size + name_len;
852 ret = iterate(num, dir, index, p, ctx);
853 if (ret)
854 goto out;
855 num++;
856 }
857
858 out:
859 btrfs_free_path(tmp_path);
860 fs_path_free(sctx, p);
861 return ret;
862 }
863
864 typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
865 const char *name, int name_len,
866 const char *data, int data_len,
867 u8 type, void *ctx);
868
869 /*
870 * Helper function to iterate the entries in ONE btrfs_dir_item.
871 * The iterate callback may return a non zero value to stop iteration. This can
872 * be a negative value for error codes or 1 to simply stop it.
873 *
874 * path must point to the dir item when called.
875 */
876 static int iterate_dir_item(struct send_ctx *sctx,
877 struct btrfs_root *root, struct btrfs_path *path,
878 struct btrfs_key *found_key,
879 iterate_dir_item_t iterate, void *ctx)
880 {
881 int ret = 0;
882 struct extent_buffer *eb;
883 struct btrfs_item *item;
884 struct btrfs_dir_item *di;
885 struct btrfs_key di_key;
886 char *buf = NULL;
887 char *buf2 = NULL;
888 int buf_len;
889 int buf_virtual = 0;
890 u32 name_len;
891 u32 data_len;
892 u32 cur;
893 u32 len;
894 u32 total;
895 int slot;
896 int num;
897 u8 type;
898
899 buf_len = PAGE_SIZE;
900 buf = kmalloc(buf_len, GFP_NOFS);
901 if (!buf) {
902 ret = -ENOMEM;
903 goto out;
904 }
905
906 eb = path->nodes[0];
907 slot = path->slots[0];
908 item = btrfs_item_nr(eb, slot);
909 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
910 cur = 0;
911 len = 0;
912 total = btrfs_item_size(eb, item);
913
914 num = 0;
915 while (cur < total) {
916 name_len = btrfs_dir_name_len(eb, di);
917 data_len = btrfs_dir_data_len(eb, di);
918 type = btrfs_dir_type(eb, di);
919 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
920
921 if (name_len + data_len > buf_len) {
922 buf_len = PAGE_ALIGN(name_len + data_len);
923 if (buf_virtual) {
924 buf2 = vmalloc(buf_len);
925 if (!buf2) {
926 ret = -ENOMEM;
927 goto out;
928 }
929 vfree(buf);
930 } else {
931 buf2 = krealloc(buf, buf_len, GFP_NOFS);
932 if (!buf2) {
933 buf2 = vmalloc(buf_len);
934 if (!buf2) {
935 ret = -ENOMEM;
936 goto out;
937 }
938 kfree(buf);
939 buf_virtual = 1;
940 }
941 }
942
943 buf = buf2;
944 buf2 = NULL;
945 }
946
947 read_extent_buffer(eb, buf, (unsigned long)(di + 1),
948 name_len + data_len);
949
950 len = sizeof(*di) + name_len + data_len;
951 di = (struct btrfs_dir_item *)((char *)di + len);
952 cur += len;
953
954 ret = iterate(num, &di_key, buf, name_len, buf + name_len,
955 data_len, type, ctx);
956 if (ret < 0)
957 goto out;
958 if (ret) {
959 ret = 0;
960 goto out;
961 }
962
963 num++;
964 }
965
966 out:
967 if (buf_virtual)
968 vfree(buf);
969 else
970 kfree(buf);
971 return ret;
972 }
973
974 static int __copy_first_ref(int num, u64 dir, int index,
975 struct fs_path *p, void *ctx)
976 {
977 int ret;
978 struct fs_path *pt = ctx;
979
980 ret = fs_path_copy(pt, p);
981 if (ret < 0)
982 return ret;
983
984 /* we want the first only */
985 return 1;
986 }
987
988 /*
989 * Retrieve the first path of an inode. If an inode has more then one
990 * ref/hardlink, this is ignored.
991 */
992 static int get_inode_path(struct send_ctx *sctx, struct btrfs_root *root,
993 u64 ino, struct fs_path *path)
994 {
995 int ret;
996 struct btrfs_key key, found_key;
997 struct btrfs_path *p;
998
999 p = alloc_path_for_send();
1000 if (!p)
1001 return -ENOMEM;
1002
1003 fs_path_reset(path);
1004
1005 key.objectid = ino;
1006 key.type = BTRFS_INODE_REF_KEY;
1007 key.offset = 0;
1008
1009 ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
1010 if (ret < 0)
1011 goto out;
1012 if (ret) {
1013 ret = 1;
1014 goto out;
1015 }
1016 btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
1017 if (found_key.objectid != ino ||
1018 (found_key.type != BTRFS_INODE_REF_KEY &&
1019 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1020 ret = -ENOENT;
1021 goto out;
1022 }
1023
1024 ret = iterate_inode_ref(sctx, root, p, &found_key, 1,
1025 __copy_first_ref, path);
1026 if (ret < 0)
1027 goto out;
1028 ret = 0;
1029
1030 out:
1031 btrfs_free_path(p);
1032 return ret;
1033 }
1034
1035 struct backref_ctx {
1036 struct send_ctx *sctx;
1037
1038 /* number of total found references */
1039 u64 found;
1040
1041 /*
1042 * used for clones found in send_root. clones found behind cur_objectid
1043 * and cur_offset are not considered as allowed clones.
1044 */
1045 u64 cur_objectid;
1046 u64 cur_offset;
1047
1048 /* may be truncated in case it's the last extent in a file */
1049 u64 extent_len;
1050
1051 /* Just to check for bugs in backref resolving */
1052 int found_itself;
1053 };
1054
1055 static int __clone_root_cmp_bsearch(const void *key, const void *elt)
1056 {
1057 u64 root = (u64)(uintptr_t)key;
1058 struct clone_root *cr = (struct clone_root *)elt;
1059
1060 if (root < cr->root->objectid)
1061 return -1;
1062 if (root > cr->root->objectid)
1063 return 1;
1064 return 0;
1065 }
1066
1067 static int __clone_root_cmp_sort(const void *e1, const void *e2)
1068 {
1069 struct clone_root *cr1 = (struct clone_root *)e1;
1070 struct clone_root *cr2 = (struct clone_root *)e2;
1071
1072 if (cr1->root->objectid < cr2->root->objectid)
1073 return -1;
1074 if (cr1->root->objectid > cr2->root->objectid)
1075 return 1;
1076 return 0;
1077 }
1078
1079 /*
1080 * Called for every backref that is found for the current extent.
1081 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1082 */
1083 static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
1084 {
1085 struct backref_ctx *bctx = ctx_;
1086 struct clone_root *found;
1087 int ret;
1088 u64 i_size;
1089
1090 /* First check if the root is in the list of accepted clone sources */
1091 found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1092 bctx->sctx->clone_roots_cnt,
1093 sizeof(struct clone_root),
1094 __clone_root_cmp_bsearch);
1095 if (!found)
1096 return 0;
1097
1098 if (found->root == bctx->sctx->send_root &&
1099 ino == bctx->cur_objectid &&
1100 offset == bctx->cur_offset) {
1101 bctx->found_itself = 1;
1102 }
1103
1104 /*
1105 * There are inodes that have extents that lie behind its i_size. Don't
1106 * accept clones from these extents.
1107 */
1108 ret = get_inode_info(found->root, ino, &i_size, NULL, NULL, NULL, NULL,
1109 NULL);
1110 if (ret < 0)
1111 return ret;
1112
1113 if (offset + bctx->extent_len > i_size)
1114 return 0;
1115
1116 /*
1117 * Make sure we don't consider clones from send_root that are
1118 * behind the current inode/offset.
1119 */
1120 if (found->root == bctx->sctx->send_root) {
1121 /*
1122 * TODO for the moment we don't accept clones from the inode
1123 * that is currently send. We may change this when
1124 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1125 * file.
1126 */
1127 if (ino >= bctx->cur_objectid)
1128 return 0;
1129 #if 0
1130 if (ino > bctx->cur_objectid)
1131 return 0;
1132 if (offset + bctx->extent_len > bctx->cur_offset)
1133 return 0;
1134 #endif
1135 }
1136
1137 bctx->found++;
1138 found->found_refs++;
1139 if (ino < found->ino) {
1140 found->ino = ino;
1141 found->offset = offset;
1142 } else if (found->ino == ino) {
1143 /*
1144 * same extent found more then once in the same file.
1145 */
1146 if (found->offset > offset + bctx->extent_len)
1147 found->offset = offset;
1148 }
1149
1150 return 0;
1151 }
1152
1153 /*
1154 * Given an inode, offset and extent item, it finds a good clone for a clone
1155 * instruction. Returns -ENOENT when none could be found. The function makes
1156 * sure that the returned clone is usable at the point where sending is at the
1157 * moment. This means, that no clones are accepted which lie behind the current
1158 * inode+offset.
1159 *
1160 * path must point to the extent item when called.
1161 */
1162 static int find_extent_clone(struct send_ctx *sctx,
1163 struct btrfs_path *path,
1164 u64 ino, u64 data_offset,
1165 u64 ino_size,
1166 struct clone_root **found)
1167 {
1168 int ret;
1169 int extent_type;
1170 u64 logical;
1171 u64 disk_byte;
1172 u64 num_bytes;
1173 u64 extent_item_pos;
1174 u64 flags = 0;
1175 struct btrfs_file_extent_item *fi;
1176 struct extent_buffer *eb = path->nodes[0];
1177 struct backref_ctx *backref_ctx = NULL;
1178 struct clone_root *cur_clone_root;
1179 struct btrfs_key found_key;
1180 struct btrfs_path *tmp_path;
1181 int compressed;
1182 u32 i;
1183
1184 tmp_path = alloc_path_for_send();
1185 if (!tmp_path)
1186 return -ENOMEM;
1187
1188 backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
1189 if (!backref_ctx) {
1190 ret = -ENOMEM;
1191 goto out;
1192 }
1193
1194 if (data_offset >= ino_size) {
1195 /*
1196 * There may be extents that lie behind the file's size.
1197 * I at least had this in combination with snapshotting while
1198 * writing large files.
1199 */
1200 ret = 0;
1201 goto out;
1202 }
1203
1204 fi = btrfs_item_ptr(eb, path->slots[0],
1205 struct btrfs_file_extent_item);
1206 extent_type = btrfs_file_extent_type(eb, fi);
1207 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1208 ret = -ENOENT;
1209 goto out;
1210 }
1211 compressed = btrfs_file_extent_compression(eb, fi);
1212
1213 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1214 disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
1215 if (disk_byte == 0) {
1216 ret = -ENOENT;
1217 goto out;
1218 }
1219 logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1220
1221 ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path,
1222 &found_key, &flags);
1223 btrfs_release_path(tmp_path);
1224
1225 if (ret < 0)
1226 goto out;
1227 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1228 ret = -EIO;
1229 goto out;
1230 }
1231
1232 /*
1233 * Setup the clone roots.
1234 */
1235 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1236 cur_clone_root = sctx->clone_roots + i;
1237 cur_clone_root->ino = (u64)-1;
1238 cur_clone_root->offset = 0;
1239 cur_clone_root->found_refs = 0;
1240 }
1241
1242 backref_ctx->sctx = sctx;
1243 backref_ctx->found = 0;
1244 backref_ctx->cur_objectid = ino;
1245 backref_ctx->cur_offset = data_offset;
1246 backref_ctx->found_itself = 0;
1247 backref_ctx->extent_len = num_bytes;
1248
1249 /*
1250 * The last extent of a file may be too large due to page alignment.
1251 * We need to adjust extent_len in this case so that the checks in
1252 * __iterate_backrefs work.
1253 */
1254 if (data_offset + num_bytes >= ino_size)
1255 backref_ctx->extent_len = ino_size - data_offset;
1256
1257 /*
1258 * Now collect all backrefs.
1259 */
1260 if (compressed == BTRFS_COMPRESS_NONE)
1261 extent_item_pos = logical - found_key.objectid;
1262 else
1263 extent_item_pos = 0;
1264
1265 extent_item_pos = logical - found_key.objectid;
1266 ret = iterate_extent_inodes(sctx->send_root->fs_info,
1267 found_key.objectid, extent_item_pos, 1,
1268 __iterate_backrefs, backref_ctx);
1269
1270 if (ret < 0)
1271 goto out;
1272
1273 if (!backref_ctx->found_itself) {
1274 /* found a bug in backref code? */
1275 ret = -EIO;
1276 printk(KERN_ERR "btrfs: ERROR did not find backref in "
1277 "send_root. inode=%llu, offset=%llu, "
1278 "disk_byte=%llu found extent=%llu\n",
1279 ino, data_offset, disk_byte, found_key.objectid);
1280 goto out;
1281 }
1282
1283 verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "
1284 "ino=%llu, "
1285 "num_bytes=%llu, logical=%llu\n",
1286 data_offset, ino, num_bytes, logical);
1287
1288 if (!backref_ctx->found)
1289 verbose_printk("btrfs: no clones found\n");
1290
1291 cur_clone_root = NULL;
1292 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1293 if (sctx->clone_roots[i].found_refs) {
1294 if (!cur_clone_root)
1295 cur_clone_root = sctx->clone_roots + i;
1296 else if (sctx->clone_roots[i].root == sctx->send_root)
1297 /* prefer clones from send_root over others */
1298 cur_clone_root = sctx->clone_roots + i;
1299 }
1300
1301 }
1302
1303 if (cur_clone_root) {
1304 *found = cur_clone_root;
1305 ret = 0;
1306 } else {
1307 ret = -ENOENT;
1308 }
1309
1310 out:
1311 btrfs_free_path(tmp_path);
1312 kfree(backref_ctx);
1313 return ret;
1314 }
1315
1316 static int read_symlink(struct send_ctx *sctx,
1317 struct btrfs_root *root,
1318 u64 ino,
1319 struct fs_path *dest)
1320 {
1321 int ret;
1322 struct btrfs_path *path;
1323 struct btrfs_key key;
1324 struct btrfs_file_extent_item *ei;
1325 u8 type;
1326 u8 compression;
1327 unsigned long off;
1328 int len;
1329
1330 path = alloc_path_for_send();
1331 if (!path)
1332 return -ENOMEM;
1333
1334 key.objectid = ino;
1335 key.type = BTRFS_EXTENT_DATA_KEY;
1336 key.offset = 0;
1337 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1338 if (ret < 0)
1339 goto out;
1340 BUG_ON(ret);
1341
1342 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
1343 struct btrfs_file_extent_item);
1344 type = btrfs_file_extent_type(path->nodes[0], ei);
1345 compression = btrfs_file_extent_compression(path->nodes[0], ei);
1346 BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
1347 BUG_ON(compression);
1348
1349 off = btrfs_file_extent_inline_start(ei);
1350 len = btrfs_file_extent_inline_len(path->nodes[0], ei);
1351
1352 ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
1353
1354 out:
1355 btrfs_free_path(path);
1356 return ret;
1357 }
1358
1359 /*
1360 * Helper function to generate a file name that is unique in the root of
1361 * send_root and parent_root. This is used to generate names for orphan inodes.
1362 */
1363 static int gen_unique_name(struct send_ctx *sctx,
1364 u64 ino, u64 gen,
1365 struct fs_path *dest)
1366 {
1367 int ret = 0;
1368 struct btrfs_path *path;
1369 struct btrfs_dir_item *di;
1370 char tmp[64];
1371 int len;
1372 u64 idx = 0;
1373
1374 path = alloc_path_for_send();
1375 if (!path)
1376 return -ENOMEM;
1377
1378 while (1) {
1379 len = snprintf(tmp, sizeof(tmp) - 1, "o%llu-%llu-%llu",
1380 ino, gen, idx);
1381 if (len >= sizeof(tmp)) {
1382 /* should really not happen */
1383 ret = -EOVERFLOW;
1384 goto out;
1385 }
1386
1387 di = btrfs_lookup_dir_item(NULL, sctx->send_root,
1388 path, BTRFS_FIRST_FREE_OBJECTID,
1389 tmp, strlen(tmp), 0);
1390 btrfs_release_path(path);
1391 if (IS_ERR(di)) {
1392 ret = PTR_ERR(di);
1393 goto out;
1394 }
1395 if (di) {
1396 /* not unique, try again */
1397 idx++;
1398 continue;
1399 }
1400
1401 if (!sctx->parent_root) {
1402 /* unique */
1403 ret = 0;
1404 break;
1405 }
1406
1407 di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
1408 path, BTRFS_FIRST_FREE_OBJECTID,
1409 tmp, strlen(tmp), 0);
1410 btrfs_release_path(path);
1411 if (IS_ERR(di)) {
1412 ret = PTR_ERR(di);
1413 goto out;
1414 }
1415 if (di) {
1416 /* not unique, try again */
1417 idx++;
1418 continue;
1419 }
1420 /* unique */
1421 break;
1422 }
1423
1424 ret = fs_path_add(dest, tmp, strlen(tmp));
1425
1426 out:
1427 btrfs_free_path(path);
1428 return ret;
1429 }
1430
1431 enum inode_state {
1432 inode_state_no_change,
1433 inode_state_will_create,
1434 inode_state_did_create,
1435 inode_state_will_delete,
1436 inode_state_did_delete,
1437 };
1438
1439 static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
1440 {
1441 int ret;
1442 int left_ret;
1443 int right_ret;
1444 u64 left_gen;
1445 u64 right_gen;
1446
1447 ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1448 NULL, NULL);
1449 if (ret < 0 && ret != -ENOENT)
1450 goto out;
1451 left_ret = ret;
1452
1453 if (!sctx->parent_root) {
1454 right_ret = -ENOENT;
1455 } else {
1456 ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1457 NULL, NULL, NULL, NULL);
1458 if (ret < 0 && ret != -ENOENT)
1459 goto out;
1460 right_ret = ret;
1461 }
1462
1463 if (!left_ret && !right_ret) {
1464 if (left_gen == gen && right_gen == gen) {
1465 ret = inode_state_no_change;
1466 } else if (left_gen == gen) {
1467 if (ino < sctx->send_progress)
1468 ret = inode_state_did_create;
1469 else
1470 ret = inode_state_will_create;
1471 } else if (right_gen == gen) {
1472 if (ino < sctx->send_progress)
1473 ret = inode_state_did_delete;
1474 else
1475 ret = inode_state_will_delete;
1476 } else {
1477 ret = -ENOENT;
1478 }
1479 } else if (!left_ret) {
1480 if (left_gen == gen) {
1481 if (ino < sctx->send_progress)
1482 ret = inode_state_did_create;
1483 else
1484 ret = inode_state_will_create;
1485 } else {
1486 ret = -ENOENT;
1487 }
1488 } else if (!right_ret) {
1489 if (right_gen == gen) {
1490 if (ino < sctx->send_progress)
1491 ret = inode_state_did_delete;
1492 else
1493 ret = inode_state_will_delete;
1494 } else {
1495 ret = -ENOENT;
1496 }
1497 } else {
1498 ret = -ENOENT;
1499 }
1500
1501 out:
1502 return ret;
1503 }
1504
1505 static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
1506 {
1507 int ret;
1508
1509 ret = get_cur_inode_state(sctx, ino, gen);
1510 if (ret < 0)
1511 goto out;
1512
1513 if (ret == inode_state_no_change ||
1514 ret == inode_state_did_create ||
1515 ret == inode_state_will_delete)
1516 ret = 1;
1517 else
1518 ret = 0;
1519
1520 out:
1521 return ret;
1522 }
1523
1524 /*
1525 * Helper function to lookup a dir item in a dir.
1526 */
1527 static int lookup_dir_item_inode(struct btrfs_root *root,
1528 u64 dir, const char *name, int name_len,
1529 u64 *found_inode,
1530 u8 *found_type)
1531 {
1532 int ret = 0;
1533 struct btrfs_dir_item *di;
1534 struct btrfs_key key;
1535 struct btrfs_path *path;
1536
1537 path = alloc_path_for_send();
1538 if (!path)
1539 return -ENOMEM;
1540
1541 di = btrfs_lookup_dir_item(NULL, root, path,
1542 dir, name, name_len, 0);
1543 if (!di) {
1544 ret = -ENOENT;
1545 goto out;
1546 }
1547 if (IS_ERR(di)) {
1548 ret = PTR_ERR(di);
1549 goto out;
1550 }
1551 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1552 *found_inode = key.objectid;
1553 *found_type = btrfs_dir_type(path->nodes[0], di);
1554
1555 out:
1556 btrfs_free_path(path);
1557 return ret;
1558 }
1559
1560 /*
1561 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
1562 * generation of the parent dir and the name of the dir entry.
1563 */
1564 static int get_first_ref(struct send_ctx *sctx,
1565 struct btrfs_root *root, u64 ino,
1566 u64 *dir, u64 *dir_gen, struct fs_path *name)
1567 {
1568 int ret;
1569 struct btrfs_key key;
1570 struct btrfs_key found_key;
1571 struct btrfs_path *path;
1572 int len;
1573 u64 parent_dir;
1574
1575 path = alloc_path_for_send();
1576 if (!path)
1577 return -ENOMEM;
1578
1579 key.objectid = ino;
1580 key.type = BTRFS_INODE_REF_KEY;
1581 key.offset = 0;
1582
1583 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
1584 if (ret < 0)
1585 goto out;
1586 if (!ret)
1587 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1588 path->slots[0]);
1589 if (ret || found_key.objectid != ino ||
1590 (found_key.type != BTRFS_INODE_REF_KEY &&
1591 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1592 ret = -ENOENT;
1593 goto out;
1594 }
1595
1596 if (key.type == BTRFS_INODE_REF_KEY) {
1597 struct btrfs_inode_ref *iref;
1598 iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1599 struct btrfs_inode_ref);
1600 len = btrfs_inode_ref_name_len(path->nodes[0], iref);
1601 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1602 (unsigned long)(iref + 1),
1603 len);
1604 parent_dir = found_key.offset;
1605 } else {
1606 struct btrfs_inode_extref *extref;
1607 extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1608 struct btrfs_inode_extref);
1609 len = btrfs_inode_extref_name_len(path->nodes[0], extref);
1610 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1611 (unsigned long)&extref->name, len);
1612 parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
1613 }
1614 if (ret < 0)
1615 goto out;
1616 btrfs_release_path(path);
1617
1618 ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
1619 NULL, NULL);
1620 if (ret < 0)
1621 goto out;
1622
1623 *dir = parent_dir;
1624
1625 out:
1626 btrfs_free_path(path);
1627 return ret;
1628 }
1629
1630 static int is_first_ref(struct send_ctx *sctx,
1631 struct btrfs_root *root,
1632 u64 ino, u64 dir,
1633 const char *name, int name_len)
1634 {
1635 int ret;
1636 struct fs_path *tmp_name;
1637 u64 tmp_dir;
1638 u64 tmp_dir_gen;
1639
1640 tmp_name = fs_path_alloc(sctx);
1641 if (!tmp_name)
1642 return -ENOMEM;
1643
1644 ret = get_first_ref(sctx, root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
1645 if (ret < 0)
1646 goto out;
1647
1648 if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1649 ret = 0;
1650 goto out;
1651 }
1652
1653 ret = !memcmp(tmp_name->start, name, name_len);
1654
1655 out:
1656 fs_path_free(sctx, tmp_name);
1657 return ret;
1658 }
1659
1660 /*
1661 * Used by process_recorded_refs to determine if a new ref would overwrite an
1662 * already existing ref. In case it detects an overwrite, it returns the
1663 * inode/gen in who_ino/who_gen.
1664 * When an overwrite is detected, process_recorded_refs does proper orphanizing
1665 * to make sure later references to the overwritten inode are possible.
1666 * Orphanizing is however only required for the first ref of an inode.
1667 * process_recorded_refs does an additional is_first_ref check to see if
1668 * orphanizing is really required.
1669 */
1670 static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
1671 const char *name, int name_len,
1672 u64 *who_ino, u64 *who_gen)
1673 {
1674 int ret = 0;
1675 u64 other_inode = 0;
1676 u8 other_type = 0;
1677
1678 if (!sctx->parent_root)
1679 goto out;
1680
1681 ret = is_inode_existent(sctx, dir, dir_gen);
1682 if (ret <= 0)
1683 goto out;
1684
1685 ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
1686 &other_inode, &other_type);
1687 if (ret < 0 && ret != -ENOENT)
1688 goto out;
1689 if (ret) {
1690 ret = 0;
1691 goto out;
1692 }
1693
1694 /*
1695 * Check if the overwritten ref was already processed. If yes, the ref
1696 * was already unlinked/moved, so we can safely assume that we will not
1697 * overwrite anything at this point in time.
1698 */
1699 if (other_inode > sctx->send_progress) {
1700 ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1701 who_gen, NULL, NULL, NULL, NULL);
1702 if (ret < 0)
1703 goto out;
1704
1705 ret = 1;
1706 *who_ino = other_inode;
1707 } else {
1708 ret = 0;
1709 }
1710
1711 out:
1712 return ret;
1713 }
1714
1715 /*
1716 * Checks if the ref was overwritten by an already processed inode. This is
1717 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
1718 * thus the orphan name needs be used.
1719 * process_recorded_refs also uses it to avoid unlinking of refs that were
1720 * overwritten.
1721 */
1722 static int did_overwrite_ref(struct send_ctx *sctx,
1723 u64 dir, u64 dir_gen,
1724 u64 ino, u64 ino_gen,
1725 const char *name, int name_len)
1726 {
1727 int ret = 0;
1728 u64 gen;
1729 u64 ow_inode;
1730 u8 other_type;
1731
1732 if (!sctx->parent_root)
1733 goto out;
1734
1735 ret = is_inode_existent(sctx, dir, dir_gen);
1736 if (ret <= 0)
1737 goto out;
1738
1739 /* check if the ref was overwritten by another ref */
1740 ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
1741 &ow_inode, &other_type);
1742 if (ret < 0 && ret != -ENOENT)
1743 goto out;
1744 if (ret) {
1745 /* was never and will never be overwritten */
1746 ret = 0;
1747 goto out;
1748 }
1749
1750 ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1751 NULL, NULL);
1752 if (ret < 0)
1753 goto out;
1754
1755 if (ow_inode == ino && gen == ino_gen) {
1756 ret = 0;
1757 goto out;
1758 }
1759
1760 /* we know that it is or will be overwritten. check this now */
1761 if (ow_inode < sctx->send_progress)
1762 ret = 1;
1763 else
1764 ret = 0;
1765
1766 out:
1767 return ret;
1768 }
1769
1770 /*
1771 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
1772 * that got overwritten. This is used by process_recorded_refs to determine
1773 * if it has to use the path as returned by get_cur_path or the orphan name.
1774 */
1775 static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
1776 {
1777 int ret = 0;
1778 struct fs_path *name = NULL;
1779 u64 dir;
1780 u64 dir_gen;
1781
1782 if (!sctx->parent_root)
1783 goto out;
1784
1785 name = fs_path_alloc(sctx);
1786 if (!name)
1787 return -ENOMEM;
1788
1789 ret = get_first_ref(sctx, sctx->parent_root, ino, &dir, &dir_gen, name);
1790 if (ret < 0)
1791 goto out;
1792
1793 ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
1794 name->start, fs_path_len(name));
1795
1796 out:
1797 fs_path_free(sctx, name);
1798 return ret;
1799 }
1800
1801 /*
1802 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
1803 * so we need to do some special handling in case we have clashes. This function
1804 * takes care of this with the help of name_cache_entry::radix_list.
1805 * In case of error, nce is kfreed.
1806 */
1807 static int name_cache_insert(struct send_ctx *sctx,
1808 struct name_cache_entry *nce)
1809 {
1810 int ret = 0;
1811 struct list_head *nce_head;
1812
1813 nce_head = radix_tree_lookup(&sctx->name_cache,
1814 (unsigned long)nce->ino);
1815 if (!nce_head) {
1816 nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
1817 if (!nce_head) {
1818 kfree(nce);
1819 return -ENOMEM;
1820 }
1821 INIT_LIST_HEAD(nce_head);
1822
1823 ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
1824 if (ret < 0) {
1825 kfree(nce_head);
1826 kfree(nce);
1827 return ret;
1828 }
1829 }
1830 list_add_tail(&nce->radix_list, nce_head);
1831 list_add_tail(&nce->list, &sctx->name_cache_list);
1832 sctx->name_cache_size++;
1833
1834 return ret;
1835 }
1836
1837 static void name_cache_delete(struct send_ctx *sctx,
1838 struct name_cache_entry *nce)
1839 {
1840 struct list_head *nce_head;
1841
1842 nce_head = radix_tree_lookup(&sctx->name_cache,
1843 (unsigned long)nce->ino);
1844 BUG_ON(!nce_head);
1845
1846 list_del(&nce->radix_list);
1847 list_del(&nce->list);
1848 sctx->name_cache_size--;
1849
1850 if (list_empty(nce_head)) {
1851 radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
1852 kfree(nce_head);
1853 }
1854 }
1855
1856 static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
1857 u64 ino, u64 gen)
1858 {
1859 struct list_head *nce_head;
1860 struct name_cache_entry *cur;
1861
1862 nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
1863 if (!nce_head)
1864 return NULL;
1865
1866 list_for_each_entry(cur, nce_head, radix_list) {
1867 if (cur->ino == ino && cur->gen == gen)
1868 return cur;
1869 }
1870 return NULL;
1871 }
1872
1873 /*
1874 * Removes the entry from the list and adds it back to the end. This marks the
1875 * entry as recently used so that name_cache_clean_unused does not remove it.
1876 */
1877 static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
1878 {
1879 list_del(&nce->list);
1880 list_add_tail(&nce->list, &sctx->name_cache_list);
1881 }
1882
1883 /*
1884 * Remove some entries from the beginning of name_cache_list.
1885 */
1886 static void name_cache_clean_unused(struct send_ctx *sctx)
1887 {
1888 struct name_cache_entry *nce;
1889
1890 if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
1891 return;
1892
1893 while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
1894 nce = list_entry(sctx->name_cache_list.next,
1895 struct name_cache_entry, list);
1896 name_cache_delete(sctx, nce);
1897 kfree(nce);
1898 }
1899 }
1900
1901 static void name_cache_free(struct send_ctx *sctx)
1902 {
1903 struct name_cache_entry *nce;
1904
1905 while (!list_empty(&sctx->name_cache_list)) {
1906 nce = list_entry(sctx->name_cache_list.next,
1907 struct name_cache_entry, list);
1908 name_cache_delete(sctx, nce);
1909 kfree(nce);
1910 }
1911 }
1912
1913 /*
1914 * Used by get_cur_path for each ref up to the root.
1915 * Returns 0 if it succeeded.
1916 * Returns 1 if the inode is not existent or got overwritten. In that case, the
1917 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
1918 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
1919 * Returns <0 in case of error.
1920 */
1921 static int __get_cur_name_and_parent(struct send_ctx *sctx,
1922 u64 ino, u64 gen,
1923 u64 *parent_ino,
1924 u64 *parent_gen,
1925 struct fs_path *dest)
1926 {
1927 int ret;
1928 int nce_ret;
1929 struct btrfs_path *path = NULL;
1930 struct name_cache_entry *nce = NULL;
1931
1932 /*
1933 * First check if we already did a call to this function with the same
1934 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
1935 * return the cached result.
1936 */
1937 nce = name_cache_search(sctx, ino, gen);
1938 if (nce) {
1939 if (ino < sctx->send_progress && nce->need_later_update) {
1940 name_cache_delete(sctx, nce);
1941 kfree(nce);
1942 nce = NULL;
1943 } else {
1944 name_cache_used(sctx, nce);
1945 *parent_ino = nce->parent_ino;
1946 *parent_gen = nce->parent_gen;
1947 ret = fs_path_add(dest, nce->name, nce->name_len);
1948 if (ret < 0)
1949 goto out;
1950 ret = nce->ret;
1951 goto out;
1952 }
1953 }
1954
1955 path = alloc_path_for_send();
1956 if (!path)
1957 return -ENOMEM;
1958
1959 /*
1960 * If the inode is not existent yet, add the orphan name and return 1.
1961 * This should only happen for the parent dir that we determine in
1962 * __record_new_ref
1963 */
1964 ret = is_inode_existent(sctx, ino, gen);
1965 if (ret < 0)
1966 goto out;
1967
1968 if (!ret) {
1969 ret = gen_unique_name(sctx, ino, gen, dest);
1970 if (ret < 0)
1971 goto out;
1972 ret = 1;
1973 goto out_cache;
1974 }
1975
1976 /*
1977 * Depending on whether the inode was already processed or not, use
1978 * send_root or parent_root for ref lookup.
1979 */
1980 if (ino < sctx->send_progress)
1981 ret = get_first_ref(sctx, sctx->send_root, ino,
1982 parent_ino, parent_gen, dest);
1983 else
1984 ret = get_first_ref(sctx, sctx->parent_root, ino,
1985 parent_ino, parent_gen, dest);
1986 if (ret < 0)
1987 goto out;
1988
1989 /*
1990 * Check if the ref was overwritten by an inode's ref that was processed
1991 * earlier. If yes, treat as orphan and return 1.
1992 */
1993 ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
1994 dest->start, dest->end - dest->start);
1995 if (ret < 0)
1996 goto out;
1997 if (ret) {
1998 fs_path_reset(dest);
1999 ret = gen_unique_name(sctx, ino, gen, dest);
2000 if (ret < 0)
2001 goto out;
2002 ret = 1;
2003 }
2004
2005 out_cache:
2006 /*
2007 * Store the result of the lookup in the name cache.
2008 */
2009 nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS);
2010 if (!nce) {
2011 ret = -ENOMEM;
2012 goto out;
2013 }
2014
2015 nce->ino = ino;
2016 nce->gen = gen;
2017 nce->parent_ino = *parent_ino;
2018 nce->parent_gen = *parent_gen;
2019 nce->name_len = fs_path_len(dest);
2020 nce->ret = ret;
2021 strcpy(nce->name, dest->start);
2022
2023 if (ino < sctx->send_progress)
2024 nce->need_later_update = 0;
2025 else
2026 nce->need_later_update = 1;
2027
2028 nce_ret = name_cache_insert(sctx, nce);
2029 if (nce_ret < 0)
2030 ret = nce_ret;
2031 name_cache_clean_unused(sctx);
2032
2033 out:
2034 btrfs_free_path(path);
2035 return ret;
2036 }
2037
2038 /*
2039 * Magic happens here. This function returns the first ref to an inode as it
2040 * would look like while receiving the stream at this point in time.
2041 * We walk the path up to the root. For every inode in between, we check if it
2042 * was already processed/sent. If yes, we continue with the parent as found
2043 * in send_root. If not, we continue with the parent as found in parent_root.
2044 * If we encounter an inode that was deleted at this point in time, we use the
2045 * inodes "orphan" name instead of the real name and stop. Same with new inodes
2046 * that were not created yet and overwritten inodes/refs.
2047 *
2048 * When do we have have orphan inodes:
2049 * 1. When an inode is freshly created and thus no valid refs are available yet
2050 * 2. When a directory lost all it's refs (deleted) but still has dir items
2051 * inside which were not processed yet (pending for move/delete). If anyone
2052 * tried to get the path to the dir items, it would get a path inside that
2053 * orphan directory.
2054 * 3. When an inode is moved around or gets new links, it may overwrite the ref
2055 * of an unprocessed inode. If in that case the first ref would be
2056 * overwritten, the overwritten inode gets "orphanized". Later when we
2057 * process this overwritten inode, it is restored at a new place by moving
2058 * the orphan inode.
2059 *
2060 * sctx->send_progress tells this function at which point in time receiving
2061 * would be.
2062 */
2063 static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
2064 struct fs_path *dest)
2065 {
2066 int ret = 0;
2067 struct fs_path *name = NULL;
2068 u64 parent_inode = 0;
2069 u64 parent_gen = 0;
2070 int stop = 0;
2071
2072 name = fs_path_alloc(sctx);
2073 if (!name) {
2074 ret = -ENOMEM;
2075 goto out;
2076 }
2077
2078 dest->reversed = 1;
2079 fs_path_reset(dest);
2080
2081 while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
2082 fs_path_reset(name);
2083
2084 ret = __get_cur_name_and_parent(sctx, ino, gen,
2085 &parent_inode, &parent_gen, name);
2086 if (ret < 0)
2087 goto out;
2088 if (ret)
2089 stop = 1;
2090
2091 ret = fs_path_add_path(dest, name);
2092 if (ret < 0)
2093 goto out;
2094
2095 ino = parent_inode;
2096 gen = parent_gen;
2097 }
2098
2099 out:
2100 fs_path_free(sctx, name);
2101 if (!ret)
2102 fs_path_unreverse(dest);
2103 return ret;
2104 }
2105
2106 /*
2107 * Called for regular files when sending extents data. Opens a struct file
2108 * to read from the file.
2109 */
2110 static int open_cur_inode_file(struct send_ctx *sctx)
2111 {
2112 int ret = 0;
2113 struct btrfs_key key;
2114 struct path path;
2115 struct inode *inode;
2116 struct dentry *dentry;
2117 struct file *filp;
2118 int new = 0;
2119
2120 if (sctx->cur_inode_filp)
2121 goto out;
2122
2123 key.objectid = sctx->cur_ino;
2124 key.type = BTRFS_INODE_ITEM_KEY;
2125 key.offset = 0;
2126
2127 inode = btrfs_iget(sctx->send_root->fs_info->sb, &key, sctx->send_root,
2128 &new);
2129 if (IS_ERR(inode)) {
2130 ret = PTR_ERR(inode);
2131 goto out;
2132 }
2133
2134 dentry = d_obtain_alias(inode);
2135 inode = NULL;
2136 if (IS_ERR(dentry)) {
2137 ret = PTR_ERR(dentry);
2138 goto out;
2139 }
2140
2141 path.mnt = sctx->mnt;
2142 path.dentry = dentry;
2143 filp = dentry_open(&path, O_RDONLY | O_LARGEFILE, current_cred());
2144 dput(dentry);
2145 dentry = NULL;
2146 if (IS_ERR(filp)) {
2147 ret = PTR_ERR(filp);
2148 goto out;
2149 }
2150 sctx->cur_inode_filp = filp;
2151
2152 out:
2153 /*
2154 * no xxxput required here as every vfs op
2155 * does it by itself on failure
2156 */
2157 return ret;
2158 }
2159
2160 /*
2161 * Closes the struct file that was created in open_cur_inode_file
2162 */
2163 static int close_cur_inode_file(struct send_ctx *sctx)
2164 {
2165 int ret = 0;
2166
2167 if (!sctx->cur_inode_filp)
2168 goto out;
2169
2170 ret = filp_close(sctx->cur_inode_filp, NULL);
2171 sctx->cur_inode_filp = NULL;
2172
2173 out:
2174 return ret;
2175 }
2176
2177 /*
2178 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2179 */
2180 static int send_subvol_begin(struct send_ctx *sctx)
2181 {
2182 int ret;
2183 struct btrfs_root *send_root = sctx->send_root;
2184 struct btrfs_root *parent_root = sctx->parent_root;
2185 struct btrfs_path *path;
2186 struct btrfs_key key;
2187 struct btrfs_root_ref *ref;
2188 struct extent_buffer *leaf;
2189 char *name = NULL;
2190 int namelen;
2191
2192 path = alloc_path_for_send();
2193 if (!path)
2194 return -ENOMEM;
2195
2196 name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS);
2197 if (!name) {
2198 btrfs_free_path(path);
2199 return -ENOMEM;
2200 }
2201
2202 key.objectid = send_root->objectid;
2203 key.type = BTRFS_ROOT_BACKREF_KEY;
2204 key.offset = 0;
2205
2206 ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
2207 &key, path, 1, 0);
2208 if (ret < 0)
2209 goto out;
2210 if (ret) {
2211 ret = -ENOENT;
2212 goto out;
2213 }
2214
2215 leaf = path->nodes[0];
2216 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2217 if (key.type != BTRFS_ROOT_BACKREF_KEY ||
2218 key.objectid != send_root->objectid) {
2219 ret = -ENOENT;
2220 goto out;
2221 }
2222 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
2223 namelen = btrfs_root_ref_name_len(leaf, ref);
2224 read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
2225 btrfs_release_path(path);
2226
2227 if (parent_root) {
2228 ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
2229 if (ret < 0)
2230 goto out;
2231 } else {
2232 ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
2233 if (ret < 0)
2234 goto out;
2235 }
2236
2237 TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
2238 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2239 sctx->send_root->root_item.uuid);
2240 TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2241 sctx->send_root->root_item.ctransid);
2242 if (parent_root) {
2243 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2244 sctx->parent_root->root_item.uuid);
2245 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2246 sctx->parent_root->root_item.ctransid);
2247 }
2248
2249 ret = send_cmd(sctx);
2250
2251 tlv_put_failure:
2252 out:
2253 btrfs_free_path(path);
2254 kfree(name);
2255 return ret;
2256 }
2257
2258 static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
2259 {
2260 int ret = 0;
2261 struct fs_path *p;
2262
2263 verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino, size);
2264
2265 p = fs_path_alloc(sctx);
2266 if (!p)
2267 return -ENOMEM;
2268
2269 ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
2270 if (ret < 0)
2271 goto out;
2272
2273 ret = get_cur_path(sctx, ino, gen, p);
2274 if (ret < 0)
2275 goto out;
2276 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2277 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
2278
2279 ret = send_cmd(sctx);
2280
2281 tlv_put_failure:
2282 out:
2283 fs_path_free(sctx, p);
2284 return ret;
2285 }
2286
2287 static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
2288 {
2289 int ret = 0;
2290 struct fs_path *p;
2291
2292 verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino, mode);
2293
2294 p = fs_path_alloc(sctx);
2295 if (!p)
2296 return -ENOMEM;
2297
2298 ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
2299 if (ret < 0)
2300 goto out;
2301
2302 ret = get_cur_path(sctx, ino, gen, p);
2303 if (ret < 0)
2304 goto out;
2305 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2306 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
2307
2308 ret = send_cmd(sctx);
2309
2310 tlv_put_failure:
2311 out:
2312 fs_path_free(sctx, p);
2313 return ret;
2314 }
2315
2316 static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
2317 {
2318 int ret = 0;
2319 struct fs_path *p;
2320
2321 verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino, uid, gid);
2322
2323 p = fs_path_alloc(sctx);
2324 if (!p)
2325 return -ENOMEM;
2326
2327 ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
2328 if (ret < 0)
2329 goto out;
2330
2331 ret = get_cur_path(sctx, ino, gen, p);
2332 if (ret < 0)
2333 goto out;
2334 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2335 TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
2336 TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
2337
2338 ret = send_cmd(sctx);
2339
2340 tlv_put_failure:
2341 out:
2342 fs_path_free(sctx, p);
2343 return ret;
2344 }
2345
2346 static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
2347 {
2348 int ret = 0;
2349 struct fs_path *p = NULL;
2350 struct btrfs_inode_item *ii;
2351 struct btrfs_path *path = NULL;
2352 struct extent_buffer *eb;
2353 struct btrfs_key key;
2354 int slot;
2355
2356 verbose_printk("btrfs: send_utimes %llu\n", ino);
2357
2358 p = fs_path_alloc(sctx);
2359 if (!p)
2360 return -ENOMEM;
2361
2362 path = alloc_path_for_send();
2363 if (!path) {
2364 ret = -ENOMEM;
2365 goto out;
2366 }
2367
2368 key.objectid = ino;
2369 key.type = BTRFS_INODE_ITEM_KEY;
2370 key.offset = 0;
2371 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2372 if (ret < 0)
2373 goto out;
2374
2375 eb = path->nodes[0];
2376 slot = path->slots[0];
2377 ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2378
2379 ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
2380 if (ret < 0)
2381 goto out;
2382
2383 ret = get_cur_path(sctx, ino, gen, p);
2384 if (ret < 0)
2385 goto out;
2386 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2387 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb,
2388 btrfs_inode_atime(ii));
2389 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb,
2390 btrfs_inode_mtime(ii));
2391 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb,
2392 btrfs_inode_ctime(ii));
2393 /* TODO Add otime support when the otime patches get into upstream */
2394
2395 ret = send_cmd(sctx);
2396
2397 tlv_put_failure:
2398 out:
2399 fs_path_free(sctx, p);
2400 btrfs_free_path(path);
2401 return ret;
2402 }
2403
2404 /*
2405 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2406 * a valid path yet because we did not process the refs yet. So, the inode
2407 * is created as orphan.
2408 */
2409 static int send_create_inode(struct send_ctx *sctx, u64 ino)
2410 {
2411 int ret = 0;
2412 struct fs_path *p;
2413 int cmd;
2414 u64 gen;
2415 u64 mode;
2416 u64 rdev;
2417
2418 verbose_printk("btrfs: send_create_inode %llu\n", ino);
2419
2420 p = fs_path_alloc(sctx);
2421 if (!p)
2422 return -ENOMEM;
2423
2424 ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode, NULL,
2425 NULL, &rdev);
2426 if (ret < 0)
2427 goto out;
2428
2429 if (S_ISREG(mode)) {
2430 cmd = BTRFS_SEND_C_MKFILE;
2431 } else if (S_ISDIR(mode)) {
2432 cmd = BTRFS_SEND_C_MKDIR;
2433 } else if (S_ISLNK(mode)) {
2434 cmd = BTRFS_SEND_C_SYMLINK;
2435 } else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2436 cmd = BTRFS_SEND_C_MKNOD;
2437 } else if (S_ISFIFO(mode)) {
2438 cmd = BTRFS_SEND_C_MKFIFO;
2439 } else if (S_ISSOCK(mode)) {
2440 cmd = BTRFS_SEND_C_MKSOCK;
2441 } else {
2442 printk(KERN_WARNING "btrfs: unexpected inode type %o",
2443 (int)(mode & S_IFMT));
2444 ret = -ENOTSUPP;
2445 goto out;
2446 }
2447
2448 ret = begin_cmd(sctx, cmd);
2449 if (ret < 0)
2450 goto out;
2451
2452 ret = gen_unique_name(sctx, ino, gen, p);
2453 if (ret < 0)
2454 goto out;
2455
2456 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2457 TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2458
2459 if (S_ISLNK(mode)) {
2460 fs_path_reset(p);
2461 ret = read_symlink(sctx, sctx->send_root, ino, p);
2462 if (ret < 0)
2463 goto out;
2464 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
2465 } else if (S_ISCHR(mode) || S_ISBLK(mode) ||
2466 S_ISFIFO(mode) || S_ISSOCK(mode)) {
2467 TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
2468 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2469 }
2470
2471 ret = send_cmd(sctx);
2472 if (ret < 0)
2473 goto out;
2474
2475
2476 tlv_put_failure:
2477 out:
2478 fs_path_free(sctx, p);
2479 return ret;
2480 }
2481
2482 /*
2483 * We need some special handling for inodes that get processed before the parent
2484 * directory got created. See process_recorded_refs for details.
2485 * This function does the check if we already created the dir out of order.
2486 */
2487 static int did_create_dir(struct send_ctx *sctx, u64 dir)
2488 {
2489 int ret = 0;
2490 struct btrfs_path *path = NULL;
2491 struct btrfs_key key;
2492 struct btrfs_key found_key;
2493 struct btrfs_key di_key;
2494 struct extent_buffer *eb;
2495 struct btrfs_dir_item *di;
2496 int slot;
2497
2498 path = alloc_path_for_send();
2499 if (!path) {
2500 ret = -ENOMEM;
2501 goto out;
2502 }
2503
2504 key.objectid = dir;
2505 key.type = BTRFS_DIR_INDEX_KEY;
2506 key.offset = 0;
2507 while (1) {
2508 ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
2509 1, 0);
2510 if (ret < 0)
2511 goto out;
2512 if (!ret) {
2513 eb = path->nodes[0];
2514 slot = path->slots[0];
2515 btrfs_item_key_to_cpu(eb, &found_key, slot);
2516 }
2517 if (ret || found_key.objectid != key.objectid ||
2518 found_key.type != key.type) {
2519 ret = 0;
2520 goto out;
2521 }
2522
2523 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2524 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2525
2526 if (di_key.objectid < sctx->send_progress) {
2527 ret = 1;
2528 goto out;
2529 }
2530
2531 key.offset = found_key.offset + 1;
2532 btrfs_release_path(path);
2533 }
2534
2535 out:
2536 btrfs_free_path(path);
2537 return ret;
2538 }
2539
2540 /*
2541 * Only creates the inode if it is:
2542 * 1. Not a directory
2543 * 2. Or a directory which was not created already due to out of order
2544 * directories. See did_create_dir and process_recorded_refs for details.
2545 */
2546 static int send_create_inode_if_needed(struct send_ctx *sctx)
2547 {
2548 int ret;
2549
2550 if (S_ISDIR(sctx->cur_inode_mode)) {
2551 ret = did_create_dir(sctx, sctx->cur_ino);
2552 if (ret < 0)
2553 goto out;
2554 if (ret) {
2555 ret = 0;
2556 goto out;
2557 }
2558 }
2559
2560 ret = send_create_inode(sctx, sctx->cur_ino);
2561 if (ret < 0)
2562 goto out;
2563
2564 out:
2565 return ret;
2566 }
2567
2568 struct recorded_ref {
2569 struct list_head list;
2570 char *dir_path;
2571 char *name;
2572 struct fs_path *full_path;
2573 u64 dir;
2574 u64 dir_gen;
2575 int dir_path_len;
2576 int name_len;
2577 };
2578
2579 /*
2580 * We need to process new refs before deleted refs, but compare_tree gives us
2581 * everything mixed. So we first record all refs and later process them.
2582 * This function is a helper to record one ref.
2583 */
2584 static int record_ref(struct list_head *head, u64 dir,
2585 u64 dir_gen, struct fs_path *path)
2586 {
2587 struct recorded_ref *ref;
2588 char *tmp;
2589
2590 ref = kmalloc(sizeof(*ref), GFP_NOFS);
2591 if (!ref)
2592 return -ENOMEM;
2593
2594 ref->dir = dir;
2595 ref->dir_gen = dir_gen;
2596 ref->full_path = path;
2597
2598 tmp = strrchr(ref->full_path->start, '/');
2599 if (!tmp) {
2600 ref->name_len = ref->full_path->end - ref->full_path->start;
2601 ref->name = ref->full_path->start;
2602 ref->dir_path_len = 0;
2603 ref->dir_path = ref->full_path->start;
2604 } else {
2605 tmp++;
2606 ref->name_len = ref->full_path->end - tmp;
2607 ref->name = tmp;
2608 ref->dir_path = ref->full_path->start;
2609 ref->dir_path_len = ref->full_path->end -
2610 ref->full_path->start - 1 - ref->name_len;
2611 }
2612
2613 list_add_tail(&ref->list, head);
2614 return 0;
2615 }
2616
2617 static void __free_recorded_refs(struct send_ctx *sctx, struct list_head *head)
2618 {
2619 struct recorded_ref *cur;
2620
2621 while (!list_empty(head)) {
2622 cur = list_entry(head->next, struct recorded_ref, list);
2623 fs_path_free(sctx, cur->full_path);
2624 list_del(&cur->list);
2625 kfree(cur);
2626 }
2627 }
2628
2629 static void free_recorded_refs(struct send_ctx *sctx)
2630 {
2631 __free_recorded_refs(sctx, &sctx->new_refs);
2632 __free_recorded_refs(sctx, &sctx->deleted_refs);
2633 }
2634
2635 /*
2636 * Renames/moves a file/dir to its orphan name. Used when the first
2637 * ref of an unprocessed inode gets overwritten and for all non empty
2638 * directories.
2639 */
2640 static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
2641 struct fs_path *path)
2642 {
2643 int ret;
2644 struct fs_path *orphan;
2645
2646 orphan = fs_path_alloc(sctx);
2647 if (!orphan)
2648 return -ENOMEM;
2649
2650 ret = gen_unique_name(sctx, ino, gen, orphan);
2651 if (ret < 0)
2652 goto out;
2653
2654 ret = send_rename(sctx, path, orphan);
2655
2656 out:
2657 fs_path_free(sctx, orphan);
2658 return ret;
2659 }
2660
2661 /*
2662 * Returns 1 if a directory can be removed at this point in time.
2663 * We check this by iterating all dir items and checking if the inode behind
2664 * the dir item was already processed.
2665 */
2666 static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 send_progress)
2667 {
2668 int ret = 0;
2669 struct btrfs_root *root = sctx->parent_root;
2670 struct btrfs_path *path;
2671 struct btrfs_key key;
2672 struct btrfs_key found_key;
2673 struct btrfs_key loc;
2674 struct btrfs_dir_item *di;
2675
2676 /*
2677 * Don't try to rmdir the top/root subvolume dir.
2678 */
2679 if (dir == BTRFS_FIRST_FREE_OBJECTID)
2680 return 0;
2681
2682 path = alloc_path_for_send();
2683 if (!path)
2684 return -ENOMEM;
2685
2686 key.objectid = dir;
2687 key.type = BTRFS_DIR_INDEX_KEY;
2688 key.offset = 0;
2689
2690 while (1) {
2691 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
2692 if (ret < 0)
2693 goto out;
2694 if (!ret) {
2695 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2696 path->slots[0]);
2697 }
2698 if (ret || found_key.objectid != key.objectid ||
2699 found_key.type != key.type) {
2700 break;
2701 }
2702
2703 di = btrfs_item_ptr(path->nodes[0], path->slots[0],
2704 struct btrfs_dir_item);
2705 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
2706
2707 if (loc.objectid > send_progress) {
2708 ret = 0;
2709 goto out;
2710 }
2711
2712 btrfs_release_path(path);
2713 key.offset = found_key.offset + 1;
2714 }
2715
2716 ret = 1;
2717
2718 out:
2719 btrfs_free_path(path);
2720 return ret;
2721 }
2722
2723 /*
2724 * This does all the move/link/unlink/rmdir magic.
2725 */
2726 static int process_recorded_refs(struct send_ctx *sctx)
2727 {
2728 int ret = 0;
2729 struct recorded_ref *cur;
2730 struct recorded_ref *cur2;
2731 struct ulist *check_dirs = NULL;
2732 struct ulist_iterator uit;
2733 struct ulist_node *un;
2734 struct fs_path *valid_path = NULL;
2735 u64 ow_inode = 0;
2736 u64 ow_gen;
2737 int did_overwrite = 0;
2738 int is_orphan = 0;
2739
2740 verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
2741
2742 /*
2743 * This should never happen as the root dir always has the same ref
2744 * which is always '..'
2745 */
2746 BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
2747
2748 valid_path = fs_path_alloc(sctx);
2749 if (!valid_path) {
2750 ret = -ENOMEM;
2751 goto out;
2752 }
2753
2754 check_dirs = ulist_alloc(GFP_NOFS);
2755 if (!check_dirs) {
2756 ret = -ENOMEM;
2757 goto out;
2758 }
2759
2760 /*
2761 * First, check if the first ref of the current inode was overwritten
2762 * before. If yes, we know that the current inode was already orphanized
2763 * and thus use the orphan name. If not, we can use get_cur_path to
2764 * get the path of the first ref as it would like while receiving at
2765 * this point in time.
2766 * New inodes are always orphan at the beginning, so force to use the
2767 * orphan name in this case.
2768 * The first ref is stored in valid_path and will be updated if it
2769 * gets moved around.
2770 */
2771 if (!sctx->cur_inode_new) {
2772 ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
2773 sctx->cur_inode_gen);
2774 if (ret < 0)
2775 goto out;
2776 if (ret)
2777 did_overwrite = 1;
2778 }
2779 if (sctx->cur_inode_new || did_overwrite) {
2780 ret = gen_unique_name(sctx, sctx->cur_ino,
2781 sctx->cur_inode_gen, valid_path);
2782 if (ret < 0)
2783 goto out;
2784 is_orphan = 1;
2785 } else {
2786 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
2787 valid_path);
2788 if (ret < 0)
2789 goto out;
2790 }
2791
2792 list_for_each_entry(cur, &sctx->new_refs, list) {
2793 /*
2794 * We may have refs where the parent directory does not exist
2795 * yet. This happens if the parent directories inum is higher
2796 * the the current inum. To handle this case, we create the
2797 * parent directory out of order. But we need to check if this
2798 * did already happen before due to other refs in the same dir.
2799 */
2800 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
2801 if (ret < 0)
2802 goto out;
2803 if (ret == inode_state_will_create) {
2804 ret = 0;
2805 /*
2806 * First check if any of the current inodes refs did
2807 * already create the dir.
2808 */
2809 list_for_each_entry(cur2, &sctx->new_refs, list) {
2810 if (cur == cur2)
2811 break;
2812 if (cur2->dir == cur->dir) {
2813 ret = 1;
2814 break;
2815 }
2816 }
2817
2818 /*
2819 * If that did not happen, check if a previous inode
2820 * did already create the dir.
2821 */
2822 if (!ret)
2823 ret = did_create_dir(sctx, cur->dir);
2824 if (ret < 0)
2825 goto out;
2826 if (!ret) {
2827 ret = send_create_inode(sctx, cur->dir);
2828 if (ret < 0)
2829 goto out;
2830 }
2831 }
2832
2833 /*
2834 * Check if this new ref would overwrite the first ref of
2835 * another unprocessed inode. If yes, orphanize the
2836 * overwritten inode. If we find an overwritten ref that is
2837 * not the first ref, simply unlink it.
2838 */
2839 ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
2840 cur->name, cur->name_len,
2841 &ow_inode, &ow_gen);
2842 if (ret < 0)
2843 goto out;
2844 if (ret) {
2845 ret = is_first_ref(sctx, sctx->parent_root,
2846 ow_inode, cur->dir, cur->name,
2847 cur->name_len);
2848 if (ret < 0)
2849 goto out;
2850 if (ret) {
2851 ret = orphanize_inode(sctx, ow_inode, ow_gen,
2852 cur->full_path);
2853 if (ret < 0)
2854 goto out;
2855 } else {
2856 ret = send_unlink(sctx, cur->full_path);
2857 if (ret < 0)
2858 goto out;
2859 }
2860 }
2861
2862 /*
2863 * link/move the ref to the new place. If we have an orphan
2864 * inode, move it and update valid_path. If not, link or move
2865 * it depending on the inode mode.
2866 */
2867 if (is_orphan) {
2868 ret = send_rename(sctx, valid_path, cur->full_path);
2869 if (ret < 0)
2870 goto out;
2871 is_orphan = 0;
2872 ret = fs_path_copy(valid_path, cur->full_path);
2873 if (ret < 0)
2874 goto out;
2875 } else {
2876 if (S_ISDIR(sctx->cur_inode_mode)) {
2877 /*
2878 * Dirs can't be linked, so move it. For moved
2879 * dirs, we always have one new and one deleted
2880 * ref. The deleted ref is ignored later.
2881 */
2882 ret = send_rename(sctx, valid_path,
2883 cur->full_path);
2884 if (ret < 0)
2885 goto out;
2886 ret = fs_path_copy(valid_path, cur->full_path);
2887 if (ret < 0)
2888 goto out;
2889 } else {
2890 ret = send_link(sctx, cur->full_path,
2891 valid_path);
2892 if (ret < 0)
2893 goto out;
2894 }
2895 }
2896 ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
2897 GFP_NOFS);
2898 if (ret < 0)
2899 goto out;
2900 }
2901
2902 if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
2903 /*
2904 * Check if we can already rmdir the directory. If not,
2905 * orphanize it. For every dir item inside that gets deleted
2906 * later, we do this check again and rmdir it then if possible.
2907 * See the use of check_dirs for more details.
2908 */
2909 ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_ino);
2910 if (ret < 0)
2911 goto out;
2912 if (ret) {
2913 ret = send_rmdir(sctx, valid_path);
2914 if (ret < 0)
2915 goto out;
2916 } else if (!is_orphan) {
2917 ret = orphanize_inode(sctx, sctx->cur_ino,
2918 sctx->cur_inode_gen, valid_path);
2919 if (ret < 0)
2920 goto out;
2921 is_orphan = 1;
2922 }
2923
2924 list_for_each_entry(cur, &sctx->deleted_refs, list) {
2925 ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
2926 GFP_NOFS);
2927 if (ret < 0)
2928 goto out;
2929 }
2930 } else if (S_ISDIR(sctx->cur_inode_mode) &&
2931 !list_empty(&sctx->deleted_refs)) {
2932 /*
2933 * We have a moved dir. Add the old parent to check_dirs
2934 */
2935 cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
2936 list);
2937 ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
2938 GFP_NOFS);
2939 if (ret < 0)
2940 goto out;
2941 } else if (!S_ISDIR(sctx->cur_inode_mode)) {
2942 /*
2943 * We have a non dir inode. Go through all deleted refs and
2944 * unlink them if they were not already overwritten by other
2945 * inodes.
2946 */
2947 list_for_each_entry(cur, &sctx->deleted_refs, list) {
2948 ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
2949 sctx->cur_ino, sctx->cur_inode_gen,
2950 cur->name, cur->name_len);
2951 if (ret < 0)
2952 goto out;
2953 if (!ret) {
2954 ret = send_unlink(sctx, cur->full_path);
2955 if (ret < 0)
2956 goto out;
2957 }
2958 ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
2959 GFP_NOFS);
2960 if (ret < 0)
2961 goto out;
2962 }
2963
2964 /*
2965 * If the inode is still orphan, unlink the orphan. This may
2966 * happen when a previous inode did overwrite the first ref
2967 * of this inode and no new refs were added for the current
2968 * inode. Unlinking does not mean that the inode is deleted in
2969 * all cases. There may still be links to this inode in other
2970 * places.
2971 */
2972 if (is_orphan) {
2973 ret = send_unlink(sctx, valid_path);
2974 if (ret < 0)
2975 goto out;
2976 }
2977 }
2978
2979 /*
2980 * We did collect all parent dirs where cur_inode was once located. We
2981 * now go through all these dirs and check if they are pending for
2982 * deletion and if it's finally possible to perform the rmdir now.
2983 * We also update the inode stats of the parent dirs here.
2984 */
2985 ULIST_ITER_INIT(&uit);
2986 while ((un = ulist_next(check_dirs, &uit))) {
2987 /*
2988 * In case we had refs into dirs that were not processed yet,
2989 * we don't need to do the utime and rmdir logic for these dirs.
2990 * The dir will be processed later.
2991 */
2992 if (un->val > sctx->cur_ino)
2993 continue;
2994
2995 ret = get_cur_inode_state(sctx, un->val, un->aux);
2996 if (ret < 0)
2997 goto out;
2998
2999 if (ret == inode_state_did_create ||
3000 ret == inode_state_no_change) {
3001 /* TODO delayed utimes */
3002 ret = send_utimes(sctx, un->val, un->aux);
3003 if (ret < 0)
3004 goto out;
3005 } else if (ret == inode_state_did_delete) {
3006 ret = can_rmdir(sctx, un->val, sctx->cur_ino);
3007 if (ret < 0)
3008 goto out;
3009 if (ret) {
3010 ret = get_cur_path(sctx, un->val, un->aux,
3011 valid_path);
3012 if (ret < 0)
3013 goto out;
3014 ret = send_rmdir(sctx, valid_path);
3015 if (ret < 0)
3016 goto out;
3017 }
3018 }
3019 }
3020
3021 ret = 0;
3022
3023 out:
3024 free_recorded_refs(sctx);
3025 ulist_free(check_dirs);
3026 fs_path_free(sctx, valid_path);
3027 return ret;
3028 }
3029
3030 static int __record_new_ref(int num, u64 dir, int index,
3031 struct fs_path *name,
3032 void *ctx)
3033 {
3034 int ret = 0;
3035 struct send_ctx *sctx = ctx;
3036 struct fs_path *p;
3037 u64 gen;
3038
3039 p = fs_path_alloc(sctx);
3040 if (!p)
3041 return -ENOMEM;
3042
3043 ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL, NULL,
3044 NULL, NULL);
3045 if (ret < 0)
3046 goto out;
3047
3048 ret = get_cur_path(sctx, dir, gen, p);
3049 if (ret < 0)
3050 goto out;
3051 ret = fs_path_add_path(p, name);
3052 if (ret < 0)
3053 goto out;
3054
3055 ret = record_ref(&sctx->new_refs, dir, gen, p);
3056
3057 out:
3058 if (ret)
3059 fs_path_free(sctx, p);
3060 return ret;
3061 }
3062
3063 static int __record_deleted_ref(int num, u64 dir, int index,
3064 struct fs_path *name,
3065 void *ctx)
3066 {
3067 int ret = 0;
3068 struct send_ctx *sctx = ctx;
3069 struct fs_path *p;
3070 u64 gen;
3071
3072 p = fs_path_alloc(sctx);
3073 if (!p)
3074 return -ENOMEM;
3075
3076 ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL, NULL,
3077 NULL, NULL);
3078 if (ret < 0)
3079 goto out;
3080
3081 ret = get_cur_path(sctx, dir, gen, p);
3082 if (ret < 0)
3083 goto out;
3084 ret = fs_path_add_path(p, name);
3085 if (ret < 0)
3086 goto out;
3087
3088 ret = record_ref(&sctx->deleted_refs, dir, gen, p);
3089
3090 out:
3091 if (ret)
3092 fs_path_free(sctx, p);
3093 return ret;
3094 }
3095
3096 static int record_new_ref(struct send_ctx *sctx)
3097 {
3098 int ret;
3099
3100 ret = iterate_inode_ref(sctx, sctx->send_root, sctx->left_path,
3101 sctx->cmp_key, 0, __record_new_ref, sctx);
3102 if (ret < 0)
3103 goto out;
3104 ret = 0;
3105
3106 out:
3107 return ret;
3108 }
3109
3110 static int record_deleted_ref(struct send_ctx *sctx)
3111 {
3112 int ret;
3113
3114 ret = iterate_inode_ref(sctx, sctx->parent_root, sctx->right_path,
3115 sctx->cmp_key, 0, __record_deleted_ref, sctx);
3116 if (ret < 0)
3117 goto out;
3118 ret = 0;
3119
3120 out:
3121 return ret;
3122 }
3123
3124 struct find_ref_ctx {
3125 u64 dir;
3126 struct fs_path *name;
3127 int found_idx;
3128 };
3129
3130 static int __find_iref(int num, u64 dir, int index,
3131 struct fs_path *name,
3132 void *ctx_)
3133 {
3134 struct find_ref_ctx *ctx = ctx_;
3135
3136 if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
3137 strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
3138 ctx->found_idx = num;
3139 return 1;
3140 }
3141 return 0;
3142 }
3143
3144 static int find_iref(struct send_ctx *sctx,
3145 struct btrfs_root *root,
3146 struct btrfs_path *path,
3147 struct btrfs_key *key,
3148 u64 dir, struct fs_path *name)
3149 {
3150 int ret;
3151 struct find_ref_ctx ctx;
3152
3153 ctx.dir = dir;
3154 ctx.name = name;
3155 ctx.found_idx = -1;
3156
3157 ret = iterate_inode_ref(sctx, root, path, key, 0, __find_iref, &ctx);
3158 if (ret < 0)
3159 return ret;
3160
3161 if (ctx.found_idx == -1)
3162 return -ENOENT;
3163
3164 return ctx.found_idx;
3165 }
3166
3167 static int __record_changed_new_ref(int num, u64 dir, int index,
3168 struct fs_path *name,
3169 void *ctx)
3170 {
3171 int ret;
3172 struct send_ctx *sctx = ctx;
3173
3174 ret = find_iref(sctx, sctx->parent_root, sctx->right_path,
3175 sctx->cmp_key, dir, name);
3176 if (ret == -ENOENT)
3177 ret = __record_new_ref(num, dir, index, name, sctx);
3178 else if (ret > 0)
3179 ret = 0;
3180
3181 return ret;
3182 }
3183
3184 static int __record_changed_deleted_ref(int num, u64 dir, int index,
3185 struct fs_path *name,
3186 void *ctx)
3187 {
3188 int ret;
3189 struct send_ctx *sctx = ctx;
3190
3191 ret = find_iref(sctx, sctx->send_root, sctx->left_path, sctx->cmp_key,
3192 dir, name);
3193 if (ret == -ENOENT)
3194 ret = __record_deleted_ref(num, dir, index, name, sctx);
3195 else if (ret > 0)
3196 ret = 0;
3197
3198 return ret;
3199 }
3200
3201 static int record_changed_ref(struct send_ctx *sctx)
3202 {
3203 int ret = 0;
3204
3205 ret = iterate_inode_ref(sctx, sctx->send_root, sctx->left_path,
3206 sctx->cmp_key, 0, __record_changed_new_ref, sctx);
3207 if (ret < 0)
3208 goto out;
3209 ret = iterate_inode_ref(sctx, sctx->parent_root, sctx->right_path,
3210 sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
3211 if (ret < 0)
3212 goto out;
3213 ret = 0;
3214
3215 out:
3216 return ret;
3217 }
3218
3219 /*
3220 * Record and process all refs at once. Needed when an inode changes the
3221 * generation number, which means that it was deleted and recreated.
3222 */
3223 static int process_all_refs(struct send_ctx *sctx,
3224 enum btrfs_compare_tree_result cmd)
3225 {
3226 int ret;
3227 struct btrfs_root *root;
3228 struct btrfs_path *path;
3229 struct btrfs_key key;
3230 struct btrfs_key found_key;
3231 struct extent_buffer *eb;
3232 int slot;
3233 iterate_inode_ref_t cb;
3234
3235 path = alloc_path_for_send();
3236 if (!path)
3237 return -ENOMEM;
3238
3239 if (cmd == BTRFS_COMPARE_TREE_NEW) {
3240 root = sctx->send_root;
3241 cb = __record_new_ref;
3242 } else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
3243 root = sctx->parent_root;
3244 cb = __record_deleted_ref;
3245 } else {
3246 BUG();
3247 }
3248
3249 key.objectid = sctx->cmp_key->objectid;
3250 key.type = BTRFS_INODE_REF_KEY;
3251 key.offset = 0;
3252 while (1) {
3253 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3254 if (ret < 0)
3255 goto out;
3256 if (ret)
3257 break;
3258
3259 eb = path->nodes[0];
3260 slot = path->slots[0];
3261 btrfs_item_key_to_cpu(eb, &found_key, slot);
3262
3263 if (found_key.objectid != key.objectid ||
3264 (found_key.type != BTRFS_INODE_REF_KEY &&
3265 found_key.type != BTRFS_INODE_EXTREF_KEY))
3266 break;
3267
3268 ret = iterate_inode_ref(sctx, root, path, &found_key, 0, cb,
3269 sctx);
3270 btrfs_release_path(path);
3271 if (ret < 0)
3272 goto out;
3273
3274 key.offset = found_key.offset + 1;
3275 }
3276 btrfs_release_path(path);
3277
3278 ret = process_recorded_refs(sctx);
3279
3280 out:
3281 btrfs_free_path(path);
3282 return ret;
3283 }
3284
3285 static int send_set_xattr(struct send_ctx *sctx,
3286 struct fs_path *path,
3287 const char *name, int name_len,
3288 const char *data, int data_len)
3289 {
3290 int ret = 0;
3291
3292 ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
3293 if (ret < 0)
3294 goto out;
3295
3296 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3297 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3298 TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
3299
3300 ret = send_cmd(sctx);
3301
3302 tlv_put_failure:
3303 out:
3304 return ret;
3305 }
3306
3307 static int send_remove_xattr(struct send_ctx *sctx,
3308 struct fs_path *path,
3309 const char *name, int name_len)
3310 {
3311 int ret = 0;
3312
3313 ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
3314 if (ret < 0)
3315 goto out;
3316
3317 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3318 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3319
3320 ret = send_cmd(sctx);
3321
3322 tlv_put_failure:
3323 out:
3324 return ret;
3325 }
3326
3327 static int __process_new_xattr(int num, struct btrfs_key *di_key,
3328 const char *name, int name_len,
3329 const char *data, int data_len,
3330 u8 type, void *ctx)
3331 {
3332 int ret;
3333 struct send_ctx *sctx = ctx;
3334 struct fs_path *p;
3335 posix_acl_xattr_header dummy_acl;
3336
3337 p = fs_path_alloc(sctx);
3338 if (!p)
3339 return -ENOMEM;
3340
3341 /*
3342 * This hack is needed because empty acl's are stored as zero byte
3343 * data in xattrs. Problem with that is, that receiving these zero byte
3344 * acl's will fail later. To fix this, we send a dummy acl list that
3345 * only contains the version number and no entries.
3346 */
3347 if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
3348 !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
3349 if (data_len == 0) {
3350 dummy_acl.a_version =
3351 cpu_to_le32(POSIX_ACL_XATTR_VERSION);
3352 data = (char *)&dummy_acl;
3353 data_len = sizeof(dummy_acl);
3354 }
3355 }
3356
3357 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3358 if (ret < 0)
3359 goto out;
3360
3361 ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
3362
3363 out:
3364 fs_path_free(sctx, p);
3365 return ret;
3366 }
3367
3368 static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
3369 const char *name, int name_len,
3370 const char *data, int data_len,
3371 u8 type, void *ctx)
3372 {
3373 int ret;
3374 struct send_ctx *sctx = ctx;
3375 struct fs_path *p;
3376
3377 p = fs_path_alloc(sctx);
3378 if (!p)
3379 return -ENOMEM;
3380
3381 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3382 if (ret < 0)
3383 goto out;
3384
3385 ret = send_remove_xattr(sctx, p, name, name_len);
3386
3387 out:
3388 fs_path_free(sctx, p);
3389 return ret;
3390 }
3391
3392 static int process_new_xattr(struct send_ctx *sctx)
3393 {
3394 int ret = 0;
3395
3396 ret = iterate_dir_item(sctx, sctx->send_root, sctx->left_path,
3397 sctx->cmp_key, __process_new_xattr, sctx);
3398
3399 return ret;
3400 }
3401
3402 static int process_deleted_xattr(struct send_ctx *sctx)
3403 {
3404 int ret;
3405
3406 ret = iterate_dir_item(sctx, sctx->parent_root, sctx->right_path,
3407 sctx->cmp_key, __process_deleted_xattr, sctx);
3408
3409 return ret;
3410 }
3411
3412 struct find_xattr_ctx {
3413 const char *name;
3414 int name_len;
3415 int found_idx;
3416 char *found_data;
3417 int found_data_len;
3418 };
3419
3420 static int __find_xattr(int num, struct btrfs_key *di_key,
3421 const char *name, int name_len,
3422 const char *data, int data_len,
3423 u8 type, void *vctx)
3424 {
3425 struct find_xattr_ctx *ctx = vctx;
3426
3427 if (name_len == ctx->name_len &&
3428 strncmp(name, ctx->name, name_len) == 0) {
3429 ctx->found_idx = num;
3430 ctx->found_data_len = data_len;
3431 ctx->found_data = kmalloc(data_len, GFP_NOFS);
3432 if (!ctx->found_data)
3433 return -ENOMEM;
3434 memcpy(ctx->found_data, data, data_len);
3435 return 1;
3436 }
3437 return 0;
3438 }
3439
3440 static int find_xattr(struct send_ctx *sctx,
3441 struct btrfs_root *root,
3442 struct btrfs_path *path,
3443 struct btrfs_key *key,
3444 const char *name, int name_len,
3445 char **data, int *data_len)
3446 {
3447 int ret;
3448 struct find_xattr_ctx ctx;
3449
3450 ctx.name = name;
3451 ctx.name_len = name_len;
3452 ctx.found_idx = -1;
3453 ctx.found_data = NULL;
3454 ctx.found_data_len = 0;
3455
3456 ret = iterate_dir_item(sctx, root, path, key, __find_xattr, &ctx);
3457 if (ret < 0)
3458 return ret;
3459
3460 if (ctx.found_idx == -1)
3461 return -ENOENT;
3462 if (data) {
3463 *data = ctx.found_data;
3464 *data_len = ctx.found_data_len;
3465 } else {
3466 kfree(ctx.found_data);
3467 }
3468 return ctx.found_idx;
3469 }
3470
3471
3472 static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
3473 const char *name, int name_len,
3474 const char *data, int data_len,
3475 u8 type, void *ctx)
3476 {
3477 int ret;
3478 struct send_ctx *sctx = ctx;
3479 char *found_data = NULL;
3480 int found_data_len = 0;
3481 struct fs_path *p = NULL;
3482
3483 ret = find_xattr(sctx, sctx->parent_root, sctx->right_path,
3484 sctx->cmp_key, name, name_len, &found_data,
3485 &found_data_len);
3486 if (ret == -ENOENT) {
3487 ret = __process_new_xattr(num, di_key, name, name_len, data,
3488 data_len, type, ctx);
3489 } else if (ret >= 0) {
3490 if (data_len != found_data_len ||
3491 memcmp(data, found_data, data_len)) {
3492 ret = __process_new_xattr(num, di_key, name, name_len,
3493 data, data_len, type, ctx);
3494 } else {
3495 ret = 0;
3496 }
3497 }
3498
3499 kfree(found_data);
3500 fs_path_free(sctx, p);
3501 return ret;
3502 }
3503
3504 static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
3505 const char *name, int name_len,
3506 const char *data, int data_len,
3507 u8 type, void *ctx)
3508 {
3509 int ret;
3510 struct send_ctx *sctx = ctx;
3511
3512 ret = find_xattr(sctx, sctx->send_root, sctx->left_path, sctx->cmp_key,
3513 name, name_len, NULL, NULL);
3514 if (ret == -ENOENT)
3515 ret = __process_deleted_xattr(num, di_key, name, name_len, data,
3516 data_len, type, ctx);
3517 else if (ret >= 0)
3518 ret = 0;
3519
3520 return ret;
3521 }
3522
3523 static int process_changed_xattr(struct send_ctx *sctx)
3524 {
3525 int ret = 0;
3526
3527 ret = iterate_dir_item(sctx, sctx->send_root, sctx->left_path,
3528 sctx->cmp_key, __process_changed_new_xattr, sctx);
3529 if (ret < 0)
3530 goto out;
3531 ret = iterate_dir_item(sctx, sctx->parent_root, sctx->right_path,
3532 sctx->cmp_key, __process_changed_deleted_xattr, sctx);
3533
3534 out:
3535 return ret;
3536 }
3537
3538 static int process_all_new_xattrs(struct send_ctx *sctx)
3539 {
3540 int ret;
3541 struct btrfs_root *root;
3542 struct btrfs_path *path;
3543 struct btrfs_key key;
3544 struct btrfs_key found_key;
3545 struct extent_buffer *eb;
3546 int slot;
3547
3548 path = alloc_path_for_send();
3549 if (!path)
3550 return -ENOMEM;
3551
3552 root = sctx->send_root;
3553
3554 key.objectid = sctx->cmp_key->objectid;
3555 key.type = BTRFS_XATTR_ITEM_KEY;
3556 key.offset = 0;
3557 while (1) {
3558 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3559 if (ret < 0)
3560 goto out;
3561 if (ret) {
3562 ret = 0;
3563 goto out;
3564 }
3565
3566 eb = path->nodes[0];
3567 slot = path->slots[0];
3568 btrfs_item_key_to_cpu(eb, &found_key, slot);
3569
3570 if (found_key.objectid != key.objectid ||
3571 found_key.type != key.type) {
3572 ret = 0;
3573 goto out;
3574 }
3575
3576 ret = iterate_dir_item(sctx, root, path, &found_key,
3577 __process_new_xattr, sctx);
3578 if (ret < 0)
3579 goto out;
3580
3581 btrfs_release_path(path);
3582 key.offset = found_key.offset + 1;
3583 }
3584
3585 out:
3586 btrfs_free_path(path);
3587 return ret;
3588 }
3589
3590 /*
3591 * Read some bytes from the current inode/file and send a write command to
3592 * user space.
3593 */
3594 static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
3595 {
3596 int ret = 0;
3597 struct fs_path *p;
3598 loff_t pos = offset;
3599 int num_read = 0;
3600 mm_segment_t old_fs;
3601
3602 p = fs_path_alloc(sctx);
3603 if (!p)
3604 return -ENOMEM;
3605
3606 /*
3607 * vfs normally only accepts user space buffers for security reasons.
3608 * we only read from the file and also only provide the read_buf buffer
3609 * to vfs. As this buffer does not come from a user space call, it's
3610 * ok to temporary allow kernel space buffers.
3611 */
3612 old_fs = get_fs();
3613 set_fs(KERNEL_DS);
3614
3615 verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len);
3616
3617 ret = open_cur_inode_file(sctx);
3618 if (ret < 0)
3619 goto out;
3620
3621 ret = vfs_read(sctx->cur_inode_filp, sctx->read_buf, len, &pos);
3622 if (ret < 0)
3623 goto out;
3624 num_read = ret;
3625 if (!num_read)
3626 goto out;
3627
3628 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
3629 if (ret < 0)
3630 goto out;
3631
3632 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3633 if (ret < 0)
3634 goto out;
3635
3636 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
3637 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
3638 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
3639
3640 ret = send_cmd(sctx);
3641
3642 tlv_put_failure:
3643 out:
3644 fs_path_free(sctx, p);
3645 set_fs(old_fs);
3646 if (ret < 0)
3647 return ret;
3648 return num_read;
3649 }
3650
3651 /*
3652 * Send a clone command to user space.
3653 */
3654 static int send_clone(struct send_ctx *sctx,
3655 u64 offset, u32 len,
3656 struct clone_root *clone_root)
3657 {
3658 int ret = 0;
3659 struct fs_path *p;
3660 u64 gen;
3661
3662 verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, "
3663 "clone_inode=%llu, clone_offset=%llu\n", offset, len,
3664 clone_root->root->objectid, clone_root->ino,
3665 clone_root->offset);
3666
3667 p = fs_path_alloc(sctx);
3668 if (!p)
3669 return -ENOMEM;
3670
3671 ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
3672 if (ret < 0)
3673 goto out;
3674
3675 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3676 if (ret < 0)
3677 goto out;
3678
3679 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
3680 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
3681 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
3682
3683 if (clone_root->root == sctx->send_root) {
3684 ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
3685 &gen, NULL, NULL, NULL, NULL);
3686 if (ret < 0)
3687 goto out;
3688 ret = get_cur_path(sctx, clone_root->ino, gen, p);
3689 } else {
3690 ret = get_inode_path(sctx, clone_root->root,
3691 clone_root->ino, p);
3692 }
3693 if (ret < 0)
3694 goto out;
3695
3696 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
3697 clone_root->root->root_item.uuid);
3698 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
3699 clone_root->root->root_item.ctransid);
3700 TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
3701 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
3702 clone_root->offset);
3703
3704 ret = send_cmd(sctx);
3705
3706 tlv_put_failure:
3707 out:
3708 fs_path_free(sctx, p);
3709 return ret;
3710 }
3711
3712 static int send_write_or_clone(struct send_ctx *sctx,
3713 struct btrfs_path *path,
3714 struct btrfs_key *key,
3715 struct clone_root *clone_root)
3716 {
3717 int ret = 0;
3718 struct btrfs_file_extent_item *ei;
3719 u64 offset = key->offset;
3720 u64 pos = 0;
3721 u64 len;
3722 u32 l;
3723 u8 type;
3724
3725 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3726 struct btrfs_file_extent_item);
3727 type = btrfs_file_extent_type(path->nodes[0], ei);
3728 if (type == BTRFS_FILE_EXTENT_INLINE) {
3729 len = btrfs_file_extent_inline_len(path->nodes[0], ei);
3730 /*
3731 * it is possible the inline item won't cover the whole page,
3732 * but there may be items after this page. Make
3733 * sure to send the whole thing
3734 */
3735 len = PAGE_CACHE_ALIGN(len);
3736 } else {
3737 len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3738 }
3739
3740 if (offset + len > sctx->cur_inode_size)
3741 len = sctx->cur_inode_size - offset;
3742 if (len == 0) {
3743 ret = 0;
3744 goto out;
3745 }
3746
3747 if (!clone_root) {
3748 while (pos < len) {
3749 l = len - pos;
3750 if (l > BTRFS_SEND_READ_SIZE)
3751 l = BTRFS_SEND_READ_SIZE;
3752 ret = send_write(sctx, pos + offset, l);
3753 if (ret < 0)
3754 goto out;
3755 if (!ret)
3756 break;
3757 pos += ret;
3758 }
3759 ret = 0;
3760 } else {
3761 ret = send_clone(sctx, offset, len, clone_root);
3762 }
3763
3764 out:
3765 return ret;
3766 }
3767
3768 static int is_extent_unchanged(struct send_ctx *sctx,
3769 struct btrfs_path *left_path,
3770 struct btrfs_key *ekey)
3771 {
3772 int ret = 0;
3773 struct btrfs_key key;
3774 struct btrfs_path *path = NULL;
3775 struct extent_buffer *eb;
3776 int slot;
3777 struct btrfs_key found_key;
3778 struct btrfs_file_extent_item *ei;
3779 u64 left_disknr;
3780 u64 right_disknr;
3781 u64 left_offset;
3782 u64 right_offset;
3783 u64 left_offset_fixed;
3784 u64 left_len;
3785 u64 right_len;
3786 u64 left_gen;
3787 u64 right_gen;
3788 u8 left_type;
3789 u8 right_type;
3790
3791 path = alloc_path_for_send();
3792 if (!path)
3793 return -ENOMEM;
3794
3795 eb = left_path->nodes[0];
3796 slot = left_path->slots[0];
3797 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
3798 left_type = btrfs_file_extent_type(eb, ei);
3799
3800 if (left_type != BTRFS_FILE_EXTENT_REG) {
3801 ret = 0;
3802 goto out;
3803 }
3804 left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
3805 left_len = btrfs_file_extent_num_bytes(eb, ei);
3806 left_offset = btrfs_file_extent_offset(eb, ei);
3807 left_gen = btrfs_file_extent_generation(eb, ei);
3808
3809 /*
3810 * Following comments will refer to these graphics. L is the left
3811 * extents which we are checking at the moment. 1-8 are the right
3812 * extents that we iterate.
3813 *
3814 * |-----L-----|
3815 * |-1-|-2a-|-3-|-4-|-5-|-6-|
3816 *
3817 * |-----L-----|
3818 * |--1--|-2b-|...(same as above)
3819 *
3820 * Alternative situation. Happens on files where extents got split.
3821 * |-----L-----|
3822 * |-----------7-----------|-6-|
3823 *
3824 * Alternative situation. Happens on files which got larger.
3825 * |-----L-----|
3826 * |-8-|
3827 * Nothing follows after 8.
3828 */
3829
3830 key.objectid = ekey->objectid;
3831 key.type = BTRFS_EXTENT_DATA_KEY;
3832 key.offset = ekey->offset;
3833 ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
3834 if (ret < 0)
3835 goto out;
3836 if (ret) {
3837 ret = 0;
3838 goto out;
3839 }
3840
3841 /*
3842 * Handle special case where the right side has no extents at all.
3843 */
3844 eb = path->nodes[0];
3845 slot = path->slots[0];
3846 btrfs_item_key_to_cpu(eb, &found_key, slot);
3847 if (found_key.objectid != key.objectid ||
3848 found_key.type != key.type) {
3849 ret = 0;
3850 goto out;
3851 }
3852
3853 /*
3854 * We're now on 2a, 2b or 7.
3855 */
3856 key = found_key;
3857 while (key.offset < ekey->offset + left_len) {
3858 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
3859 right_type = btrfs_file_extent_type(eb, ei);
3860 right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
3861 right_len = btrfs_file_extent_num_bytes(eb, ei);
3862 right_offset = btrfs_file_extent_offset(eb, ei);
3863 right_gen = btrfs_file_extent_generation(eb, ei);
3864
3865 if (right_type != BTRFS_FILE_EXTENT_REG) {
3866 ret = 0;
3867 goto out;
3868 }
3869
3870 /*
3871 * Are we at extent 8? If yes, we know the extent is changed.
3872 * This may only happen on the first iteration.
3873 */
3874 if (found_key.offset + right_len <= ekey->offset) {
3875 ret = 0;
3876 goto out;
3877 }
3878
3879 left_offset_fixed = left_offset;
3880 if (key.offset < ekey->offset) {
3881 /* Fix the right offset for 2a and 7. */
3882 right_offset += ekey->offset - key.offset;
3883 } else {
3884 /* Fix the left offset for all behind 2a and 2b */
3885 left_offset_fixed += key.offset - ekey->offset;
3886 }
3887
3888 /*
3889 * Check if we have the same extent.
3890 */
3891 if (left_disknr != right_disknr ||
3892 left_offset_fixed != right_offset ||
3893 left_gen != right_gen) {
3894 ret = 0;
3895 goto out;
3896 }
3897
3898 /*
3899 * Go to the next extent.
3900 */
3901 ret = btrfs_next_item(sctx->parent_root, path);
3902 if (ret < 0)
3903 goto out;
3904 if (!ret) {
3905 eb = path->nodes[0];
3906 slot = path->slots[0];
3907 btrfs_item_key_to_cpu(eb, &found_key, slot);
3908 }
3909 if (ret || found_key.objectid != key.objectid ||
3910 found_key.type != key.type) {
3911 key.offset += right_len;
3912 break;
3913 } else {
3914 if (found_key.offset != key.offset + right_len) {
3915 /* Should really not happen */
3916 ret = -EIO;
3917 goto out;
3918 }
3919 }
3920 key = found_key;
3921 }
3922
3923 /*
3924 * We're now behind the left extent (treat as unchanged) or at the end
3925 * of the right side (treat as changed).
3926 */
3927 if (key.offset >= ekey->offset + left_len)
3928 ret = 1;
3929 else
3930 ret = 0;
3931
3932
3933 out:
3934 btrfs_free_path(path);
3935 return ret;
3936 }
3937
3938 static int process_extent(struct send_ctx *sctx,
3939 struct btrfs_path *path,
3940 struct btrfs_key *key)
3941 {
3942 int ret = 0;
3943 struct clone_root *found_clone = NULL;
3944
3945 if (S_ISLNK(sctx->cur_inode_mode))
3946 return 0;
3947
3948 if (sctx->parent_root && !sctx->cur_inode_new) {
3949 ret = is_extent_unchanged(sctx, path, key);
3950 if (ret < 0)
3951 goto out;
3952 if (ret) {
3953 ret = 0;
3954 goto out;
3955 }
3956 }
3957
3958 ret = find_extent_clone(sctx, path, key->objectid, key->offset,
3959 sctx->cur_inode_size, &found_clone);
3960 if (ret != -ENOENT && ret < 0)
3961 goto out;
3962
3963 ret = send_write_or_clone(sctx, path, key, found_clone);
3964
3965 out:
3966 return ret;
3967 }
3968
3969 static int process_all_extents(struct send_ctx *sctx)
3970 {
3971 int ret;
3972 struct btrfs_root *root;
3973 struct btrfs_path *path;
3974 struct btrfs_key key;
3975 struct btrfs_key found_key;
3976 struct extent_buffer *eb;
3977 int slot;
3978
3979 root = sctx->send_root;
3980 path = alloc_path_for_send();
3981 if (!path)
3982 return -ENOMEM;
3983
3984 key.objectid = sctx->cmp_key->objectid;
3985 key.type = BTRFS_EXTENT_DATA_KEY;
3986 key.offset = 0;
3987 while (1) {
3988 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3989 if (ret < 0)
3990 goto out;
3991 if (ret) {
3992 ret = 0;
3993 goto out;
3994 }
3995
3996 eb = path->nodes[0];
3997 slot = path->slots[0];
3998 btrfs_item_key_to_cpu(eb, &found_key, slot);
3999
4000 if (found_key.objectid != key.objectid ||
4001 found_key.type != key.type) {
4002 ret = 0;
4003 goto out;
4004 }
4005
4006 ret = process_extent(sctx, path, &found_key);
4007 if (ret < 0)
4008 goto out;
4009
4010 btrfs_release_path(path);
4011 key.offset = found_key.offset + 1;
4012 }
4013
4014 out:
4015 btrfs_free_path(path);
4016 return ret;
4017 }
4018
4019 static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end)
4020 {
4021 int ret = 0;
4022
4023 if (sctx->cur_ino == 0)
4024 goto out;
4025 if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
4026 sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
4027 goto out;
4028 if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
4029 goto out;
4030
4031 ret = process_recorded_refs(sctx);
4032 if (ret < 0)
4033 goto out;
4034
4035 /*
4036 * We have processed the refs and thus need to advance send_progress.
4037 * Now, calls to get_cur_xxx will take the updated refs of the current
4038 * inode into account.
4039 */
4040 sctx->send_progress = sctx->cur_ino + 1;
4041
4042 out:
4043 return ret;
4044 }
4045
4046 static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
4047 {
4048 int ret = 0;
4049 u64 left_mode;
4050 u64 left_uid;
4051 u64 left_gid;
4052 u64 right_mode;
4053 u64 right_uid;
4054 u64 right_gid;
4055 int need_chmod = 0;
4056 int need_chown = 0;
4057
4058 ret = process_recorded_refs_if_needed(sctx, at_end);
4059 if (ret < 0)
4060 goto out;
4061
4062 if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
4063 goto out;
4064 if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
4065 goto out;
4066
4067 ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
4068 &left_mode, &left_uid, &left_gid, NULL);
4069 if (ret < 0)
4070 goto out;
4071
4072 if (!sctx->parent_root || sctx->cur_inode_new) {
4073 need_chown = 1;
4074 if (!S_ISLNK(sctx->cur_inode_mode))
4075 need_chmod = 1;
4076 } else {
4077 ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
4078 NULL, NULL, &right_mode, &right_uid,
4079 &right_gid, NULL);
4080 if (ret < 0)
4081 goto out;
4082
4083 if (left_uid != right_uid || left_gid != right_gid)
4084 need_chown = 1;
4085 if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
4086 need_chmod = 1;
4087 }
4088
4089 if (S_ISREG(sctx->cur_inode_mode)) {
4090 ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4091 sctx->cur_inode_size);
4092 if (ret < 0)
4093 goto out;
4094 }
4095
4096 if (need_chown) {
4097 ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4098 left_uid, left_gid);
4099 if (ret < 0)
4100 goto out;
4101 }
4102 if (need_chmod) {
4103 ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4104 left_mode);
4105 if (ret < 0)
4106 goto out;
4107 }
4108
4109 /*
4110 * Need to send that every time, no matter if it actually changed
4111 * between the two trees as we have done changes to the inode before.
4112 */
4113 ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
4114 if (ret < 0)
4115 goto out;
4116
4117 out:
4118 return ret;
4119 }
4120
4121 static int changed_inode(struct send_ctx *sctx,
4122 enum btrfs_compare_tree_result result)
4123 {
4124 int ret = 0;
4125 struct btrfs_key *key = sctx->cmp_key;
4126 struct btrfs_inode_item *left_ii = NULL;
4127 struct btrfs_inode_item *right_ii = NULL;
4128 u64 left_gen = 0;
4129 u64 right_gen = 0;
4130
4131 ret = close_cur_inode_file(sctx);
4132 if (ret < 0)
4133 goto out;
4134
4135 sctx->cur_ino = key->objectid;
4136 sctx->cur_inode_new_gen = 0;
4137
4138 /*
4139 * Set send_progress to current inode. This will tell all get_cur_xxx
4140 * functions that the current inode's refs are not updated yet. Later,
4141 * when process_recorded_refs is finished, it is set to cur_ino + 1.
4142 */
4143 sctx->send_progress = sctx->cur_ino;
4144
4145 if (result == BTRFS_COMPARE_TREE_NEW ||
4146 result == BTRFS_COMPARE_TREE_CHANGED) {
4147 left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
4148 sctx->left_path->slots[0],
4149 struct btrfs_inode_item);
4150 left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
4151 left_ii);
4152 } else {
4153 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
4154 sctx->right_path->slots[0],
4155 struct btrfs_inode_item);
4156 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
4157 right_ii);
4158 }
4159 if (result == BTRFS_COMPARE_TREE_CHANGED) {
4160 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
4161 sctx->right_path->slots[0],
4162 struct btrfs_inode_item);
4163
4164 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
4165 right_ii);
4166
4167 /*
4168 * The cur_ino = root dir case is special here. We can't treat
4169 * the inode as deleted+reused because it would generate a
4170 * stream that tries to delete/mkdir the root dir.
4171 */
4172 if (left_gen != right_gen &&
4173 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
4174 sctx->cur_inode_new_gen = 1;
4175 }
4176
4177 if (result == BTRFS_COMPARE_TREE_NEW) {
4178 sctx->cur_inode_gen = left_gen;
4179 sctx->cur_inode_new = 1;
4180 sctx->cur_inode_deleted = 0;
4181 sctx->cur_inode_size = btrfs_inode_size(
4182 sctx->left_path->nodes[0], left_ii);
4183 sctx->cur_inode_mode = btrfs_inode_mode(
4184 sctx->left_path->nodes[0], left_ii);
4185 if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
4186 ret = send_create_inode_if_needed(sctx);
4187 } else if (result == BTRFS_COMPARE_TREE_DELETED) {
4188 sctx->cur_inode_gen = right_gen;
4189 sctx->cur_inode_new = 0;
4190 sctx->cur_inode_deleted = 1;
4191 sctx->cur_inode_size = btrfs_inode_size(
4192 sctx->right_path->nodes[0], right_ii);
4193 sctx->cur_inode_mode = btrfs_inode_mode(
4194 sctx->right_path->nodes[0], right_ii);
4195 } else if (result == BTRFS_COMPARE_TREE_CHANGED) {
4196 /*
4197 * We need to do some special handling in case the inode was
4198 * reported as changed with a changed generation number. This
4199 * means that the original inode was deleted and new inode
4200 * reused the same inum. So we have to treat the old inode as
4201 * deleted and the new one as new.
4202 */
4203 if (sctx->cur_inode_new_gen) {
4204 /*
4205 * First, process the inode as if it was deleted.
4206 */
4207 sctx->cur_inode_gen = right_gen;
4208 sctx->cur_inode_new = 0;
4209 sctx->cur_inode_deleted = 1;
4210 sctx->cur_inode_size = btrfs_inode_size(
4211 sctx->right_path->nodes[0], right_ii);
4212 sctx->cur_inode_mode = btrfs_inode_mode(
4213 sctx->right_path->nodes[0], right_ii);
4214 ret = process_all_refs(sctx,
4215 BTRFS_COMPARE_TREE_DELETED);
4216 if (ret < 0)
4217 goto out;
4218
4219 /*
4220 * Now process the inode as if it was new.
4221 */
4222 sctx->cur_inode_gen = left_gen;
4223 sctx->cur_inode_new = 1;
4224 sctx->cur_inode_deleted = 0;
4225 sctx->cur_inode_size = btrfs_inode_size(
4226 sctx->left_path->nodes[0], left_ii);
4227 sctx->cur_inode_mode = btrfs_inode_mode(
4228 sctx->left_path->nodes[0], left_ii);
4229 ret = send_create_inode_if_needed(sctx);
4230 if (ret < 0)
4231 goto out;
4232
4233 ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
4234 if (ret < 0)
4235 goto out;
4236 /*
4237 * Advance send_progress now as we did not get into
4238 * process_recorded_refs_if_needed in the new_gen case.
4239 */
4240 sctx->send_progress = sctx->cur_ino + 1;
4241
4242 /*
4243 * Now process all extents and xattrs of the inode as if
4244 * they were all new.
4245 */
4246 ret = process_all_extents(sctx);
4247 if (ret < 0)
4248 goto out;
4249 ret = process_all_new_xattrs(sctx);
4250 if (ret < 0)
4251 goto out;
4252 } else {
4253 sctx->cur_inode_gen = left_gen;
4254 sctx->cur_inode_new = 0;
4255 sctx->cur_inode_new_gen = 0;
4256 sctx->cur_inode_deleted = 0;
4257 sctx->cur_inode_size = btrfs_inode_size(
4258 sctx->left_path->nodes[0], left_ii);
4259 sctx->cur_inode_mode = btrfs_inode_mode(
4260 sctx->left_path->nodes[0], left_ii);
4261 }
4262 }
4263
4264 out:
4265 return ret;
4266 }
4267
4268 /*
4269 * We have to process new refs before deleted refs, but compare_trees gives us
4270 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
4271 * first and later process them in process_recorded_refs.
4272 * For the cur_inode_new_gen case, we skip recording completely because
4273 * changed_inode did already initiate processing of refs. The reason for this is
4274 * that in this case, compare_tree actually compares the refs of 2 different
4275 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
4276 * refs of the right tree as deleted and all refs of the left tree as new.
4277 */
4278 static int changed_ref(struct send_ctx *sctx,
4279 enum btrfs_compare_tree_result result)
4280 {
4281 int ret = 0;
4282
4283 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4284
4285 if (!sctx->cur_inode_new_gen &&
4286 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
4287 if (result == BTRFS_COMPARE_TREE_NEW)
4288 ret = record_new_ref(sctx);
4289 else if (result == BTRFS_COMPARE_TREE_DELETED)
4290 ret = record_deleted_ref(sctx);
4291 else if (result == BTRFS_COMPARE_TREE_CHANGED)
4292 ret = record_changed_ref(sctx);
4293 }
4294
4295 return ret;
4296 }
4297
4298 /*
4299 * Process new/deleted/changed xattrs. We skip processing in the
4300 * cur_inode_new_gen case because changed_inode did already initiate processing
4301 * of xattrs. The reason is the same as in changed_ref
4302 */
4303 static int changed_xattr(struct send_ctx *sctx,
4304 enum btrfs_compare_tree_result result)
4305 {
4306 int ret = 0;
4307
4308 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4309
4310 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
4311 if (result == BTRFS_COMPARE_TREE_NEW)
4312 ret = process_new_xattr(sctx);
4313 else if (result == BTRFS_COMPARE_TREE_DELETED)
4314 ret = process_deleted_xattr(sctx);
4315 else if (result == BTRFS_COMPARE_TREE_CHANGED)
4316 ret = process_changed_xattr(sctx);
4317 }
4318
4319 return ret;
4320 }
4321
4322 /*
4323 * Process new/deleted/changed extents. We skip processing in the
4324 * cur_inode_new_gen case because changed_inode did already initiate processing
4325 * of extents. The reason is the same as in changed_ref
4326 */
4327 static int changed_extent(struct send_ctx *sctx,
4328 enum btrfs_compare_tree_result result)
4329 {
4330 int ret = 0;
4331
4332 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4333
4334 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
4335 if (result != BTRFS_COMPARE_TREE_DELETED)
4336 ret = process_extent(sctx, sctx->left_path,
4337 sctx->cmp_key);
4338 }
4339
4340 return ret;
4341 }
4342
4343 /*
4344 * Updates compare related fields in sctx and simply forwards to the actual
4345 * changed_xxx functions.
4346 */
4347 static int changed_cb(struct btrfs_root *left_root,
4348 struct btrfs_root *right_root,
4349 struct btrfs_path *left_path,
4350 struct btrfs_path *right_path,
4351 struct btrfs_key *key,
4352 enum btrfs_compare_tree_result result,
4353 void *ctx)
4354 {
4355 int ret = 0;
4356 struct send_ctx *sctx = ctx;
4357
4358 sctx->left_path = left_path;
4359 sctx->right_path = right_path;
4360 sctx->cmp_key = key;
4361
4362 ret = finish_inode_if_needed(sctx, 0);
4363 if (ret < 0)
4364 goto out;
4365
4366 /* Ignore non-FS objects */
4367 if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
4368 key->objectid == BTRFS_FREE_SPACE_OBJECTID)
4369 goto out;
4370
4371 if (key->type == BTRFS_INODE_ITEM_KEY)
4372 ret = changed_inode(sctx, result);
4373 else if (key->type == BTRFS_INODE_REF_KEY ||
4374 key->type == BTRFS_INODE_EXTREF_KEY)
4375 ret = changed_ref(sctx, result);
4376 else if (key->type == BTRFS_XATTR_ITEM_KEY)
4377 ret = changed_xattr(sctx, result);
4378 else if (key->type == BTRFS_EXTENT_DATA_KEY)
4379 ret = changed_extent(sctx, result);
4380
4381 out:
4382 return ret;
4383 }
4384
4385 static int full_send_tree(struct send_ctx *sctx)
4386 {
4387 int ret;
4388 struct btrfs_trans_handle *trans = NULL;
4389 struct btrfs_root *send_root = sctx->send_root;
4390 struct btrfs_key key;
4391 struct btrfs_key found_key;
4392 struct btrfs_path *path;
4393 struct extent_buffer *eb;
4394 int slot;
4395 u64 start_ctransid;
4396 u64 ctransid;
4397
4398 path = alloc_path_for_send();
4399 if (!path)
4400 return -ENOMEM;
4401
4402 spin_lock(&send_root->root_item_lock);
4403 start_ctransid = btrfs_root_ctransid(&send_root->root_item);
4404 spin_unlock(&send_root->root_item_lock);
4405
4406 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
4407 key.type = BTRFS_INODE_ITEM_KEY;
4408 key.offset = 0;
4409
4410 join_trans:
4411 /*
4412 * We need to make sure the transaction does not get committed
4413 * while we do anything on commit roots. Join a transaction to prevent
4414 * this.
4415 */
4416 trans = btrfs_join_transaction(send_root);
4417 if (IS_ERR(trans)) {
4418 ret = PTR_ERR(trans);
4419 trans = NULL;
4420 goto out;
4421 }
4422
4423 /*
4424 * Make sure the tree has not changed after re-joining. We detect this
4425 * by comparing start_ctransid and ctransid. They should always match.
4426 */
4427 spin_lock(&send_root->root_item_lock);
4428 ctransid = btrfs_root_ctransid(&send_root->root_item);
4429 spin_unlock(&send_root->root_item_lock);
4430
4431 if (ctransid != start_ctransid) {
4432 WARN(1, KERN_WARNING "btrfs: the root that you're trying to "
4433 "send was modified in between. This is "
4434 "probably a bug.\n");
4435 ret = -EIO;
4436 goto out;
4437 }
4438
4439 ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
4440 if (ret < 0)
4441 goto out;
4442 if (ret)
4443 goto out_finish;
4444
4445 while (1) {
4446 /*
4447 * When someone want to commit while we iterate, end the
4448 * joined transaction and rejoin.
4449 */
4450 if (btrfs_should_end_transaction(trans, send_root)) {
4451 ret = btrfs_end_transaction(trans, send_root);
4452 trans = NULL;
4453 if (ret < 0)
4454 goto out;
4455 btrfs_release_path(path);
4456 goto join_trans;
4457 }
4458
4459 eb = path->nodes[0];
4460 slot = path->slots[0];
4461 btrfs_item_key_to_cpu(eb, &found_key, slot);
4462
4463 ret = changed_cb(send_root, NULL, path, NULL,
4464 &found_key, BTRFS_COMPARE_TREE_NEW, sctx);
4465 if (ret < 0)
4466 goto out;
4467
4468 key.objectid = found_key.objectid;
4469 key.type = found_key.type;
4470 key.offset = found_key.offset + 1;
4471
4472 ret = btrfs_next_item(send_root, path);
4473 if (ret < 0)
4474 goto out;
4475 if (ret) {
4476 ret = 0;
4477 break;
4478 }
4479 }
4480
4481 out_finish:
4482 ret = finish_inode_if_needed(sctx, 1);
4483
4484 out:
4485 btrfs_free_path(path);
4486 if (trans) {
4487 if (!ret)
4488 ret = btrfs_end_transaction(trans, send_root);
4489 else
4490 btrfs_end_transaction(trans, send_root);
4491 }
4492 return ret;
4493 }
4494
4495 static int send_subvol(struct send_ctx *sctx)
4496 {
4497 int ret;
4498
4499 ret = send_header(sctx);
4500 if (ret < 0)
4501 goto out;
4502
4503 ret = send_subvol_begin(sctx);
4504 if (ret < 0)
4505 goto out;
4506
4507 if (sctx->parent_root) {
4508 ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
4509 changed_cb, sctx);
4510 if (ret < 0)
4511 goto out;
4512 ret = finish_inode_if_needed(sctx, 1);
4513 if (ret < 0)
4514 goto out;
4515 } else {
4516 ret = full_send_tree(sctx);
4517 if (ret < 0)
4518 goto out;
4519 }
4520
4521 out:
4522 if (!ret)
4523 ret = close_cur_inode_file(sctx);
4524 else
4525 close_cur_inode_file(sctx);
4526
4527 free_recorded_refs(sctx);
4528 return ret;
4529 }
4530
4531 long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
4532 {
4533 int ret = 0;
4534 struct btrfs_root *send_root;
4535 struct btrfs_root *clone_root;
4536 struct btrfs_fs_info *fs_info;
4537 struct btrfs_ioctl_send_args *arg = NULL;
4538 struct btrfs_key key;
4539 struct file *filp = NULL;
4540 struct send_ctx *sctx = NULL;
4541 u32 i;
4542 u64 *clone_sources_tmp = NULL;
4543
4544 if (!capable(CAP_SYS_ADMIN))
4545 return -EPERM;
4546
4547 send_root = BTRFS_I(file_inode(mnt_file))->root;
4548 fs_info = send_root->fs_info;
4549
4550 arg = memdup_user(arg_, sizeof(*arg));
4551 if (IS_ERR(arg)) {
4552 ret = PTR_ERR(arg);
4553 arg = NULL;
4554 goto out;
4555 }
4556
4557 if (!access_ok(VERIFY_READ, arg->clone_sources,
4558 sizeof(*arg->clone_sources *
4559 arg->clone_sources_count))) {
4560 ret = -EFAULT;
4561 goto out;
4562 }
4563
4564 sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
4565 if (!sctx) {
4566 ret = -ENOMEM;
4567 goto out;
4568 }
4569
4570 INIT_LIST_HEAD(&sctx->new_refs);
4571 INIT_LIST_HEAD(&sctx->deleted_refs);
4572 INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
4573 INIT_LIST_HEAD(&sctx->name_cache_list);
4574
4575 sctx->send_filp = fget(arg->send_fd);
4576 if (IS_ERR(sctx->send_filp)) {
4577 ret = PTR_ERR(sctx->send_filp);
4578 goto out;
4579 }
4580
4581 sctx->mnt = mnt_file->f_path.mnt;
4582
4583 sctx->send_root = send_root;
4584 sctx->clone_roots_cnt = arg->clone_sources_count;
4585
4586 sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
4587 sctx->send_buf = vmalloc(sctx->send_max_size);
4588 if (!sctx->send_buf) {
4589 ret = -ENOMEM;
4590 goto out;
4591 }
4592
4593 sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE);
4594 if (!sctx->read_buf) {
4595 ret = -ENOMEM;
4596 goto out;
4597 }
4598
4599 sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
4600 (arg->clone_sources_count + 1));
4601 if (!sctx->clone_roots) {
4602 ret = -ENOMEM;
4603 goto out;
4604 }
4605
4606 if (arg->clone_sources_count) {
4607 clone_sources_tmp = vmalloc(arg->clone_sources_count *
4608 sizeof(*arg->clone_sources));
4609 if (!clone_sources_tmp) {
4610 ret = -ENOMEM;
4611 goto out;
4612 }
4613
4614 ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
4615 arg->clone_sources_count *
4616 sizeof(*arg->clone_sources));
4617 if (ret) {
4618 ret = -EFAULT;
4619 goto out;
4620 }
4621
4622 for (i = 0; i < arg->clone_sources_count; i++) {
4623 key.objectid = clone_sources_tmp[i];
4624 key.type = BTRFS_ROOT_ITEM_KEY;
4625 key.offset = (u64)-1;
4626 clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
4627 if (!clone_root) {
4628 ret = -EINVAL;
4629 goto out;
4630 }
4631 if (IS_ERR(clone_root)) {
4632 ret = PTR_ERR(clone_root);
4633 goto out;
4634 }
4635 sctx->clone_roots[i].root = clone_root;
4636 }
4637 vfree(clone_sources_tmp);
4638 clone_sources_tmp = NULL;
4639 }
4640
4641 if (arg->parent_root) {
4642 key.objectid = arg->parent_root;
4643 key.type = BTRFS_ROOT_ITEM_KEY;
4644 key.offset = (u64)-1;
4645 sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
4646 if (!sctx->parent_root) {
4647 ret = -EINVAL;
4648 goto out;
4649 }
4650 }
4651
4652 /*
4653 * Clones from send_root are allowed, but only if the clone source
4654 * is behind the current send position. This is checked while searching
4655 * for possible clone sources.
4656 */
4657 sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;
4658
4659 /* We do a bsearch later */
4660 sort(sctx->clone_roots, sctx->clone_roots_cnt,
4661 sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
4662 NULL);
4663
4664 ret = send_subvol(sctx);
4665 if (ret < 0)
4666 goto out;
4667
4668 ret = begin_cmd(sctx, BTRFS_SEND_C_END);
4669 if (ret < 0)
4670 goto out;
4671 ret = send_cmd(sctx);
4672 if (ret < 0)
4673 goto out;
4674
4675 out:
4676 if (filp)
4677 fput(filp);
4678 kfree(arg);
4679 vfree(clone_sources_tmp);
4680
4681 if (sctx) {
4682 if (sctx->send_filp)
4683 fput(sctx->send_filp);
4684
4685 vfree(sctx->clone_roots);
4686 vfree(sctx->send_buf);
4687 vfree(sctx->read_buf);
4688
4689 name_cache_free(sctx);
4690
4691 kfree(sctx);
4692 }
4693
4694 return ret;
4695 }
kernel source for telekom puls (alcatel/mediatek)