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Merge tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream
[deliverable/linux.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 int cur_inode_first_ref_orphan;
111 u64 cur_inode_size;
112 u64 cur_inode_mode;
113
114 u64 send_progress;
115
116 struct list_head new_refs;
117 struct list_head deleted_refs;
118
119 struct radix_tree_root name_cache;
120 struct list_head name_cache_list;
121 int name_cache_size;
122
123 struct file *cur_inode_filp;
124 char *read_buf;
125 };
126
127 struct name_cache_entry {
128 struct list_head list;
129 struct list_head use_list;
130 u64 ino;
131 u64 gen;
132 u64 parent_ino;
133 u64 parent_gen;
134 int ret;
135 int need_later_update;
136 int name_len;
137 char name[];
138 };
139
140 static void fs_path_reset(struct fs_path *p)
141 {
142 if (p->reversed) {
143 p->start = p->buf + p->buf_len - 1;
144 p->end = p->start;
145 *p->start = 0;
146 } else {
147 p->start = p->buf;
148 p->end = p->start;
149 *p->start = 0;
150 }
151 }
152
153 static struct fs_path *fs_path_alloc(struct send_ctx *sctx)
154 {
155 struct fs_path *p;
156
157 p = kmalloc(sizeof(*p), GFP_NOFS);
158 if (!p)
159 return NULL;
160 p->reversed = 0;
161 p->virtual_mem = 0;
162 p->buf = p->inline_buf;
163 p->buf_len = FS_PATH_INLINE_SIZE;
164 fs_path_reset(p);
165 return p;
166 }
167
168 static struct fs_path *fs_path_alloc_reversed(struct send_ctx *sctx)
169 {
170 struct fs_path *p;
171
172 p = fs_path_alloc(sctx);
173 if (!p)
174 return NULL;
175 p->reversed = 1;
176 fs_path_reset(p);
177 return p;
178 }
179
180 static void fs_path_free(struct send_ctx *sctx, struct fs_path *p)
181 {
182 if (!p)
183 return;
184 if (p->buf != p->inline_buf) {
185 if (p->virtual_mem)
186 vfree(p->buf);
187 else
188 kfree(p->buf);
189 }
190 kfree(p);
191 }
192
193 static int fs_path_len(struct fs_path *p)
194 {
195 return p->end - p->start;
196 }
197
198 static int fs_path_ensure_buf(struct fs_path *p, int len)
199 {
200 char *tmp_buf;
201 int path_len;
202 int old_buf_len;
203
204 len++;
205
206 if (p->buf_len >= len)
207 return 0;
208
209 path_len = p->end - p->start;
210 old_buf_len = p->buf_len;
211 len = PAGE_ALIGN(len);
212
213 if (p->buf == p->inline_buf) {
214 tmp_buf = kmalloc(len, GFP_NOFS);
215 if (!tmp_buf) {
216 tmp_buf = vmalloc(len);
217 if (!tmp_buf)
218 return -ENOMEM;
219 p->virtual_mem = 1;
220 }
221 memcpy(tmp_buf, p->buf, p->buf_len);
222 p->buf = tmp_buf;
223 p->buf_len = len;
224 } else {
225 if (p->virtual_mem) {
226 tmp_buf = vmalloc(len);
227 if (!tmp_buf)
228 return -ENOMEM;
229 memcpy(tmp_buf, p->buf, p->buf_len);
230 vfree(p->buf);
231 } else {
232 tmp_buf = krealloc(p->buf, len, GFP_NOFS);
233 if (!tmp_buf) {
234 tmp_buf = vmalloc(len);
235 if (!tmp_buf)
236 return -ENOMEM;
237 memcpy(tmp_buf, p->buf, p->buf_len);
238 kfree(p->buf);
239 p->virtual_mem = 1;
240 }
241 }
242 p->buf = tmp_buf;
243 p->buf_len = len;
244 }
245 if (p->reversed) {
246 tmp_buf = p->buf + old_buf_len - path_len - 1;
247 p->end = p->buf + p->buf_len - 1;
248 p->start = p->end - path_len;
249 memmove(p->start, tmp_buf, path_len + 1);
250 } else {
251 p->start = p->buf;
252 p->end = p->start + path_len;
253 }
254 return 0;
255 }
256
257 static int fs_path_prepare_for_add(struct fs_path *p, int name_len)
258 {
259 int ret;
260 int new_len;
261
262 new_len = p->end - p->start + name_len;
263 if (p->start != p->end)
264 new_len++;
265 ret = fs_path_ensure_buf(p, new_len);
266 if (ret < 0)
267 goto out;
268
269 if (p->reversed) {
270 if (p->start != p->end)
271 *--p->start = '/';
272 p->start -= name_len;
273 p->prepared = p->start;
274 } else {
275 if (p->start != p->end)
276 *p->end++ = '/';
277 p->prepared = p->end;
278 p->end += name_len;
279 *p->end = 0;
280 }
281
282 out:
283 return ret;
284 }
285
286 static int fs_path_add(struct fs_path *p, const char *name, int name_len)
287 {
288 int ret;
289
290 ret = fs_path_prepare_for_add(p, name_len);
291 if (ret < 0)
292 goto out;
293 memcpy(p->prepared, name, name_len);
294 p->prepared = NULL;
295
296 out:
297 return ret;
298 }
299
300 static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
301 {
302 int ret;
303
304 ret = fs_path_prepare_for_add(p, p2->end - p2->start);
305 if (ret < 0)
306 goto out;
307 memcpy(p->prepared, p2->start, p2->end - p2->start);
308 p->prepared = NULL;
309
310 out:
311 return ret;
312 }
313
314 static int fs_path_add_from_extent_buffer(struct fs_path *p,
315 struct extent_buffer *eb,
316 unsigned long off, int len)
317 {
318 int ret;
319
320 ret = fs_path_prepare_for_add(p, len);
321 if (ret < 0)
322 goto out;
323
324 read_extent_buffer(eb, p->prepared, off, len);
325 p->prepared = NULL;
326
327 out:
328 return ret;
329 }
330
331 static void fs_path_remove(struct fs_path *p)
332 {
333 BUG_ON(p->reversed);
334 while (p->start != p->end && *p->end != '/')
335 p->end--;
336 *p->end = 0;
337 }
338
339 static int fs_path_copy(struct fs_path *p, struct fs_path *from)
340 {
341 int ret;
342
343 p->reversed = from->reversed;
344 fs_path_reset(p);
345
346 ret = fs_path_add_path(p, from);
347
348 return ret;
349 }
350
351
352 static void fs_path_unreverse(struct fs_path *p)
353 {
354 char *tmp;
355 int len;
356
357 if (!p->reversed)
358 return;
359
360 tmp = p->start;
361 len = p->end - p->start;
362 p->start = p->buf;
363 p->end = p->start + len;
364 memmove(p->start, tmp, len + 1);
365 p->reversed = 0;
366 }
367
368 static struct btrfs_path *alloc_path_for_send(void)
369 {
370 struct btrfs_path *path;
371
372 path = btrfs_alloc_path();
373 if (!path)
374 return NULL;
375 path->search_commit_root = 1;
376 path->skip_locking = 1;
377 return path;
378 }
379
380 static int write_buf(struct send_ctx *sctx, const void *buf, u32 len)
381 {
382 int ret;
383 mm_segment_t old_fs;
384 u32 pos = 0;
385
386 old_fs = get_fs();
387 set_fs(KERNEL_DS);
388
389 while (pos < len) {
390 ret = vfs_write(sctx->send_filp, (char *)buf + pos, len - pos,
391 &sctx->send_off);
392 /* TODO handle that correctly */
393 /*if (ret == -ERESTARTSYS) {
394 continue;
395 }*/
396 if (ret < 0)
397 goto out;
398 if (ret == 0) {
399 ret = -EIO;
400 goto out;
401 }
402 pos += ret;
403 }
404
405 ret = 0;
406
407 out:
408 set_fs(old_fs);
409 return ret;
410 }
411
412 static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
413 {
414 struct btrfs_tlv_header *hdr;
415 int total_len = sizeof(*hdr) + len;
416 int left = sctx->send_max_size - sctx->send_size;
417
418 if (unlikely(left < total_len))
419 return -EOVERFLOW;
420
421 hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
422 hdr->tlv_type = cpu_to_le16(attr);
423 hdr->tlv_len = cpu_to_le16(len);
424 memcpy(hdr + 1, data, len);
425 sctx->send_size += total_len;
426
427 return 0;
428 }
429
430 #if 0
431 static int tlv_put_u8(struct send_ctx *sctx, u16 attr, u8 value)
432 {
433 return tlv_put(sctx, attr, &value, sizeof(value));
434 }
435
436 static int tlv_put_u16(struct send_ctx *sctx, u16 attr, u16 value)
437 {
438 __le16 tmp = cpu_to_le16(value);
439 return tlv_put(sctx, attr, &tmp, sizeof(tmp));
440 }
441
442 static int tlv_put_u32(struct send_ctx *sctx, u16 attr, u32 value)
443 {
444 __le32 tmp = cpu_to_le32(value);
445 return tlv_put(sctx, attr, &tmp, sizeof(tmp));
446 }
447 #endif
448
449 static int tlv_put_u64(struct send_ctx *sctx, u16 attr, u64 value)
450 {
451 __le64 tmp = cpu_to_le64(value);
452 return tlv_put(sctx, attr, &tmp, sizeof(tmp));
453 }
454
455 static int tlv_put_string(struct send_ctx *sctx, u16 attr,
456 const char *str, int len)
457 {
458 if (len == -1)
459 len = strlen(str);
460 return tlv_put(sctx, attr, str, len);
461 }
462
463 static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
464 const u8 *uuid)
465 {
466 return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
467 }
468
469 #if 0
470 static int tlv_put_timespec(struct send_ctx *sctx, u16 attr,
471 struct timespec *ts)
472 {
473 struct btrfs_timespec bts;
474 bts.sec = cpu_to_le64(ts->tv_sec);
475 bts.nsec = cpu_to_le32(ts->tv_nsec);
476 return tlv_put(sctx, attr, &bts, sizeof(bts));
477 }
478 #endif
479
480 static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
481 struct extent_buffer *eb,
482 struct btrfs_timespec *ts)
483 {
484 struct btrfs_timespec bts;
485 read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
486 return tlv_put(sctx, attr, &bts, sizeof(bts));
487 }
488
489
490 #define TLV_PUT(sctx, attrtype, attrlen, data) \
491 do { \
492 ret = tlv_put(sctx, attrtype, attrlen, data); \
493 if (ret < 0) \
494 goto tlv_put_failure; \
495 } while (0)
496
497 #define TLV_PUT_INT(sctx, attrtype, bits, value) \
498 do { \
499 ret = tlv_put_u##bits(sctx, attrtype, value); \
500 if (ret < 0) \
501 goto tlv_put_failure; \
502 } while (0)
503
504 #define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
505 #define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
506 #define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
507 #define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
508 #define TLV_PUT_STRING(sctx, attrtype, str, len) \
509 do { \
510 ret = tlv_put_string(sctx, attrtype, str, len); \
511 if (ret < 0) \
512 goto tlv_put_failure; \
513 } while (0)
514 #define TLV_PUT_PATH(sctx, attrtype, p) \
515 do { \
516 ret = tlv_put_string(sctx, attrtype, p->start, \
517 p->end - p->start); \
518 if (ret < 0) \
519 goto tlv_put_failure; \
520 } while(0)
521 #define TLV_PUT_UUID(sctx, attrtype, uuid) \
522 do { \
523 ret = tlv_put_uuid(sctx, attrtype, uuid); \
524 if (ret < 0) \
525 goto tlv_put_failure; \
526 } while (0)
527 #define TLV_PUT_TIMESPEC(sctx, attrtype, ts) \
528 do { \
529 ret = tlv_put_timespec(sctx, attrtype, ts); \
530 if (ret < 0) \
531 goto tlv_put_failure; \
532 } while (0)
533 #define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
534 do { \
535 ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
536 if (ret < 0) \
537 goto tlv_put_failure; \
538 } while (0)
539
540 static int send_header(struct send_ctx *sctx)
541 {
542 struct btrfs_stream_header hdr;
543
544 strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
545 hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
546
547 return write_buf(sctx, &hdr, sizeof(hdr));
548 }
549
550 /*
551 * For each command/item we want to send to userspace, we call this function.
552 */
553 static int begin_cmd(struct send_ctx *sctx, int cmd)
554 {
555 struct btrfs_cmd_header *hdr;
556
557 if (!sctx->send_buf) {
558 WARN_ON(1);
559 return -EINVAL;
560 }
561
562 BUG_ON(sctx->send_size);
563
564 sctx->send_size += sizeof(*hdr);
565 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
566 hdr->cmd = cpu_to_le16(cmd);
567
568 return 0;
569 }
570
571 static int send_cmd(struct send_ctx *sctx)
572 {
573 int ret;
574 struct btrfs_cmd_header *hdr;
575 u32 crc;
576
577 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
578 hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
579 hdr->crc = 0;
580
581 crc = crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
582 hdr->crc = cpu_to_le32(crc);
583
584 ret = write_buf(sctx, sctx->send_buf, sctx->send_size);
585
586 sctx->total_send_size += sctx->send_size;
587 sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
588 sctx->send_size = 0;
589
590 return ret;
591 }
592
593 /*
594 * Sends a move instruction to user space
595 */
596 static int send_rename(struct send_ctx *sctx,
597 struct fs_path *from, struct fs_path *to)
598 {
599 int ret;
600
601 verbose_printk("btrfs: send_rename %s -> %s\n", from->start, to->start);
602
603 ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
604 if (ret < 0)
605 goto out;
606
607 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
608 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
609
610 ret = send_cmd(sctx);
611
612 tlv_put_failure:
613 out:
614 return ret;
615 }
616
617 /*
618 * Sends a link instruction to user space
619 */
620 static int send_link(struct send_ctx *sctx,
621 struct fs_path *path, struct fs_path *lnk)
622 {
623 int ret;
624
625 verbose_printk("btrfs: send_link %s -> %s\n", path->start, lnk->start);
626
627 ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
628 if (ret < 0)
629 goto out;
630
631 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
632 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
633
634 ret = send_cmd(sctx);
635
636 tlv_put_failure:
637 out:
638 return ret;
639 }
640
641 /*
642 * Sends an unlink instruction to user space
643 */
644 static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
645 {
646 int ret;
647
648 verbose_printk("btrfs: send_unlink %s\n", path->start);
649
650 ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
651 if (ret < 0)
652 goto out;
653
654 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
655
656 ret = send_cmd(sctx);
657
658 tlv_put_failure:
659 out:
660 return ret;
661 }
662
663 /*
664 * Sends a rmdir instruction to user space
665 */
666 static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
667 {
668 int ret;
669
670 verbose_printk("btrfs: send_rmdir %s\n", path->start);
671
672 ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
673 if (ret < 0)
674 goto out;
675
676 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
677
678 ret = send_cmd(sctx);
679
680 tlv_put_failure:
681 out:
682 return ret;
683 }
684
685 /*
686 * Helper function to retrieve some fields from an inode item.
687 */
688 static int get_inode_info(struct btrfs_root *root,
689 u64 ino, u64 *size, u64 *gen,
690 u64 *mode, u64 *uid, u64 *gid)
691 {
692 int ret;
693 struct btrfs_inode_item *ii;
694 struct btrfs_key key;
695 struct btrfs_path *path;
696
697 path = alloc_path_for_send();
698 if (!path)
699 return -ENOMEM;
700
701 key.objectid = ino;
702 key.type = BTRFS_INODE_ITEM_KEY;
703 key.offset = 0;
704 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
705 if (ret < 0)
706 goto out;
707 if (ret) {
708 ret = -ENOENT;
709 goto out;
710 }
711
712 ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
713 struct btrfs_inode_item);
714 if (size)
715 *size = btrfs_inode_size(path->nodes[0], ii);
716 if (gen)
717 *gen = btrfs_inode_generation(path->nodes[0], ii);
718 if (mode)
719 *mode = btrfs_inode_mode(path->nodes[0], ii);
720 if (uid)
721 *uid = btrfs_inode_uid(path->nodes[0], ii);
722 if (gid)
723 *gid = btrfs_inode_gid(path->nodes[0], ii);
724
725 out:
726 btrfs_free_path(path);
727 return ret;
728 }
729
730 typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
731 struct fs_path *p,
732 void *ctx);
733
734 /*
735 * Helper function to iterate the entries in ONE btrfs_inode_ref.
736 * The iterate callback may return a non zero value to stop iteration. This can
737 * be a negative value for error codes or 1 to simply stop it.
738 *
739 * path must point to the INODE_REF when called.
740 */
741 static int iterate_inode_ref(struct send_ctx *sctx,
742 struct btrfs_root *root, struct btrfs_path *path,
743 struct btrfs_key *found_key, int resolve,
744 iterate_inode_ref_t iterate, void *ctx)
745 {
746 struct extent_buffer *eb;
747 struct btrfs_item *item;
748 struct btrfs_inode_ref *iref;
749 struct btrfs_path *tmp_path;
750 struct fs_path *p;
751 u32 cur;
752 u32 len;
753 u32 total;
754 int slot;
755 u32 name_len;
756 char *start;
757 int ret = 0;
758 int num;
759 int index;
760
761 p = fs_path_alloc_reversed(sctx);
762 if (!p)
763 return -ENOMEM;
764
765 tmp_path = alloc_path_for_send();
766 if (!tmp_path) {
767 fs_path_free(sctx, p);
768 return -ENOMEM;
769 }
770
771 eb = path->nodes[0];
772 slot = path->slots[0];
773 item = btrfs_item_nr(eb, slot);
774 iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
775 cur = 0;
776 len = 0;
777 total = btrfs_item_size(eb, item);
778
779 num = 0;
780 while (cur < total) {
781 fs_path_reset(p);
782
783 name_len = btrfs_inode_ref_name_len(eb, iref);
784 index = btrfs_inode_ref_index(eb, iref);
785 if (resolve) {
786 start = btrfs_iref_to_path(root, tmp_path, iref, eb,
787 found_key->offset, p->buf,
788 p->buf_len);
789 if (IS_ERR(start)) {
790 ret = PTR_ERR(start);
791 goto out;
792 }
793 if (start < p->buf) {
794 /* overflow , try again with larger buffer */
795 ret = fs_path_ensure_buf(p,
796 p->buf_len + p->buf - start);
797 if (ret < 0)
798 goto out;
799 start = btrfs_iref_to_path(root, tmp_path, iref,
800 eb, found_key->offset, p->buf,
801 p->buf_len);
802 if (IS_ERR(start)) {
803 ret = PTR_ERR(start);
804 goto out;
805 }
806 BUG_ON(start < p->buf);
807 }
808 p->start = start;
809 } else {
810 ret = fs_path_add_from_extent_buffer(p, eb,
811 (unsigned long)(iref + 1), name_len);
812 if (ret < 0)
813 goto out;
814 }
815
816
817 len = sizeof(*iref) + name_len;
818 iref = (struct btrfs_inode_ref *)((char *)iref + len);
819 cur += len;
820
821 ret = iterate(num, found_key->offset, index, p, ctx);
822 if (ret)
823 goto out;
824
825 num++;
826 }
827
828 out:
829 btrfs_free_path(tmp_path);
830 fs_path_free(sctx, p);
831 return ret;
832 }
833
834 typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
835 const char *name, int name_len,
836 const char *data, int data_len,
837 u8 type, void *ctx);
838
839 /*
840 * Helper function to iterate the entries in ONE btrfs_dir_item.
841 * The iterate callback may return a non zero value to stop iteration. This can
842 * be a negative value for error codes or 1 to simply stop it.
843 *
844 * path must point to the dir item when called.
845 */
846 static int iterate_dir_item(struct send_ctx *sctx,
847 struct btrfs_root *root, struct btrfs_path *path,
848 struct btrfs_key *found_key,
849 iterate_dir_item_t iterate, void *ctx)
850 {
851 int ret = 0;
852 struct extent_buffer *eb;
853 struct btrfs_item *item;
854 struct btrfs_dir_item *di;
855 struct btrfs_path *tmp_path = NULL;
856 struct btrfs_key di_key;
857 char *buf = NULL;
858 char *buf2 = NULL;
859 int buf_len;
860 int buf_virtual = 0;
861 u32 name_len;
862 u32 data_len;
863 u32 cur;
864 u32 len;
865 u32 total;
866 int slot;
867 int num;
868 u8 type;
869
870 buf_len = PAGE_SIZE;
871 buf = kmalloc(buf_len, GFP_NOFS);
872 if (!buf) {
873 ret = -ENOMEM;
874 goto out;
875 }
876
877 tmp_path = alloc_path_for_send();
878 if (!tmp_path) {
879 ret = -ENOMEM;
880 goto out;
881 }
882
883 eb = path->nodes[0];
884 slot = path->slots[0];
885 item = btrfs_item_nr(eb, slot);
886 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
887 cur = 0;
888 len = 0;
889 total = btrfs_item_size(eb, item);
890
891 num = 0;
892 while (cur < total) {
893 name_len = btrfs_dir_name_len(eb, di);
894 data_len = btrfs_dir_data_len(eb, di);
895 type = btrfs_dir_type(eb, di);
896 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
897
898 if (name_len + data_len > buf_len) {
899 buf_len = PAGE_ALIGN(name_len + data_len);
900 if (buf_virtual) {
901 buf2 = vmalloc(buf_len);
902 if (!buf2) {
903 ret = -ENOMEM;
904 goto out;
905 }
906 vfree(buf);
907 } else {
908 buf2 = krealloc(buf, buf_len, GFP_NOFS);
909 if (!buf2) {
910 buf2 = vmalloc(buf_len);
911 if (!buf2) {
912 ret = -ENOMEM;
913 goto out;
914 }
915 kfree(buf);
916 buf_virtual = 1;
917 }
918 }
919
920 buf = buf2;
921 buf2 = NULL;
922 }
923
924 read_extent_buffer(eb, buf, (unsigned long)(di + 1),
925 name_len + data_len);
926
927 len = sizeof(*di) + name_len + data_len;
928 di = (struct btrfs_dir_item *)((char *)di + len);
929 cur += len;
930
931 ret = iterate(num, &di_key, buf, name_len, buf + name_len,
932 data_len, type, ctx);
933 if (ret < 0)
934 goto out;
935 if (ret) {
936 ret = 0;
937 goto out;
938 }
939
940 num++;
941 }
942
943 out:
944 btrfs_free_path(tmp_path);
945 if (buf_virtual)
946 vfree(buf);
947 else
948 kfree(buf);
949 return ret;
950 }
951
952 static int __copy_first_ref(int num, u64 dir, int index,
953 struct fs_path *p, void *ctx)
954 {
955 int ret;
956 struct fs_path *pt = ctx;
957
958 ret = fs_path_copy(pt, p);
959 if (ret < 0)
960 return ret;
961
962 /* we want the first only */
963 return 1;
964 }
965
966 /*
967 * Retrieve the first path of an inode. If an inode has more then one
968 * ref/hardlink, this is ignored.
969 */
970 static int get_inode_path(struct send_ctx *sctx, struct btrfs_root *root,
971 u64 ino, struct fs_path *path)
972 {
973 int ret;
974 struct btrfs_key key, found_key;
975 struct btrfs_path *p;
976
977 p = alloc_path_for_send();
978 if (!p)
979 return -ENOMEM;
980
981 fs_path_reset(path);
982
983 key.objectid = ino;
984 key.type = BTRFS_INODE_REF_KEY;
985 key.offset = 0;
986
987 ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
988 if (ret < 0)
989 goto out;
990 if (ret) {
991 ret = 1;
992 goto out;
993 }
994 btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
995 if (found_key.objectid != ino ||
996 found_key.type != BTRFS_INODE_REF_KEY) {
997 ret = -ENOENT;
998 goto out;
999 }
1000
1001 ret = iterate_inode_ref(sctx, root, p, &found_key, 1,
1002 __copy_first_ref, path);
1003 if (ret < 0)
1004 goto out;
1005 ret = 0;
1006
1007 out:
1008 btrfs_free_path(p);
1009 return ret;
1010 }
1011
1012 struct backref_ctx {
1013 struct send_ctx *sctx;
1014
1015 /* number of total found references */
1016 u64 found;
1017
1018 /*
1019 * used for clones found in send_root. clones found behind cur_objectid
1020 * and cur_offset are not considered as allowed clones.
1021 */
1022 u64 cur_objectid;
1023 u64 cur_offset;
1024
1025 /* may be truncated in case it's the last extent in a file */
1026 u64 extent_len;
1027
1028 /* Just to check for bugs in backref resolving */
1029 int found_in_send_root;
1030 };
1031
1032 static int __clone_root_cmp_bsearch(const void *key, const void *elt)
1033 {
1034 u64 root = (u64)key;
1035 struct clone_root *cr = (struct clone_root *)elt;
1036
1037 if (root < cr->root->objectid)
1038 return -1;
1039 if (root > cr->root->objectid)
1040 return 1;
1041 return 0;
1042 }
1043
1044 static int __clone_root_cmp_sort(const void *e1, const void *e2)
1045 {
1046 struct clone_root *cr1 = (struct clone_root *)e1;
1047 struct clone_root *cr2 = (struct clone_root *)e2;
1048
1049 if (cr1->root->objectid < cr2->root->objectid)
1050 return -1;
1051 if (cr1->root->objectid > cr2->root->objectid)
1052 return 1;
1053 return 0;
1054 }
1055
1056 /*
1057 * Called for every backref that is found for the current extent.
1058 */
1059 static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
1060 {
1061 struct backref_ctx *bctx = ctx_;
1062 struct clone_root *found;
1063 int ret;
1064 u64 i_size;
1065
1066 /* First check if the root is in the list of accepted clone sources */
1067 found = bsearch((void *)root, bctx->sctx->clone_roots,
1068 bctx->sctx->clone_roots_cnt,
1069 sizeof(struct clone_root),
1070 __clone_root_cmp_bsearch);
1071 if (!found)
1072 return 0;
1073
1074 if (found->root == bctx->sctx->send_root &&
1075 ino == bctx->cur_objectid &&
1076 offset == bctx->cur_offset) {
1077 bctx->found_in_send_root = 1;
1078 }
1079
1080 /*
1081 * There are inodes that have extents that lie behind it's i_size. Don't
1082 * accept clones from these extents.
1083 */
1084 ret = get_inode_info(found->root, ino, &i_size, NULL, NULL, NULL, NULL);
1085 if (ret < 0)
1086 return ret;
1087
1088 if (offset + bctx->extent_len > i_size)
1089 return 0;
1090
1091 /*
1092 * Make sure we don't consider clones from send_root that are
1093 * behind the current inode/offset.
1094 */
1095 if (found->root == bctx->sctx->send_root) {
1096 /*
1097 * TODO for the moment we don't accept clones from the inode
1098 * that is currently send. We may change this when
1099 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1100 * file.
1101 */
1102 if (ino >= bctx->cur_objectid)
1103 return 0;
1104 /*if (ino > ctx->cur_objectid)
1105 return 0;
1106 if (offset + ctx->extent_len > ctx->cur_offset)
1107 return 0;*/
1108
1109 bctx->found++;
1110 found->found_refs++;
1111 found->ino = ino;
1112 found->offset = offset;
1113 return 0;
1114 }
1115
1116 bctx->found++;
1117 found->found_refs++;
1118 if (ino < found->ino) {
1119 found->ino = ino;
1120 found->offset = offset;
1121 } else if (found->ino == ino) {
1122 /*
1123 * same extent found more then once in the same file.
1124 */
1125 if (found->offset > offset + bctx->extent_len)
1126 found->offset = offset;
1127 }
1128
1129 return 0;
1130 }
1131
1132 /*
1133 * path must point to the extent item when called.
1134 */
1135 static int find_extent_clone(struct send_ctx *sctx,
1136 struct btrfs_path *path,
1137 u64 ino, u64 data_offset,
1138 u64 ino_size,
1139 struct clone_root **found)
1140 {
1141 int ret;
1142 int extent_type;
1143 u64 logical;
1144 u64 num_bytes;
1145 u64 extent_item_pos;
1146 struct btrfs_file_extent_item *fi;
1147 struct extent_buffer *eb = path->nodes[0];
1148 struct backref_ctx backref_ctx;
1149 struct clone_root *cur_clone_root;
1150 struct btrfs_key found_key;
1151 struct btrfs_path *tmp_path;
1152 u32 i;
1153
1154 tmp_path = alloc_path_for_send();
1155 if (!tmp_path)
1156 return -ENOMEM;
1157
1158 if (data_offset >= ino_size) {
1159 /*
1160 * There may be extents that lie behind the file's size.
1161 * I at least had this in combination with snapshotting while
1162 * writing large files.
1163 */
1164 ret = 0;
1165 goto out;
1166 }
1167
1168 fi = btrfs_item_ptr(eb, path->slots[0],
1169 struct btrfs_file_extent_item);
1170 extent_type = btrfs_file_extent_type(eb, fi);
1171 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1172 ret = -ENOENT;
1173 goto out;
1174 }
1175
1176 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1177 logical = btrfs_file_extent_disk_bytenr(eb, fi);
1178 if (logical == 0) {
1179 ret = -ENOENT;
1180 goto out;
1181 }
1182 logical += btrfs_file_extent_offset(eb, fi);
1183
1184 ret = extent_from_logical(sctx->send_root->fs_info,
1185 logical, tmp_path, &found_key);
1186 btrfs_release_path(tmp_path);
1187
1188 if (ret < 0)
1189 goto out;
1190 if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1191 ret = -EIO;
1192 goto out;
1193 }
1194
1195 /*
1196 * Setup the clone roots.
1197 */
1198 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1199 cur_clone_root = sctx->clone_roots + i;
1200 cur_clone_root->ino = (u64)-1;
1201 cur_clone_root->offset = 0;
1202 cur_clone_root->found_refs = 0;
1203 }
1204
1205 backref_ctx.sctx = sctx;
1206 backref_ctx.found = 0;
1207 backref_ctx.cur_objectid = ino;
1208 backref_ctx.cur_offset = data_offset;
1209 backref_ctx.found_in_send_root = 0;
1210 backref_ctx.extent_len = num_bytes;
1211
1212 /*
1213 * The last extent of a file may be too large due to page alignment.
1214 * We need to adjust extent_len in this case so that the checks in
1215 * __iterate_backrefs work.
1216 */
1217 if (data_offset + num_bytes >= ino_size)
1218 backref_ctx.extent_len = ino_size - data_offset;
1219
1220 /*
1221 * Now collect all backrefs.
1222 */
1223 extent_item_pos = logical - found_key.objectid;
1224 ret = iterate_extent_inodes(sctx->send_root->fs_info,
1225 found_key.objectid, extent_item_pos, 1,
1226 __iterate_backrefs, &backref_ctx);
1227 if (ret < 0)
1228 goto out;
1229
1230 if (!backref_ctx.found_in_send_root) {
1231 /* found a bug in backref code? */
1232 ret = -EIO;
1233 printk(KERN_ERR "btrfs: ERROR did not find backref in "
1234 "send_root. inode=%llu, offset=%llu, "
1235 "logical=%llu\n",
1236 ino, data_offset, logical);
1237 goto out;
1238 }
1239
1240 verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "
1241 "ino=%llu, "
1242 "num_bytes=%llu, logical=%llu\n",
1243 data_offset, ino, num_bytes, logical);
1244
1245 if (!backref_ctx.found)
1246 verbose_printk("btrfs: no clones found\n");
1247
1248 cur_clone_root = NULL;
1249 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1250 if (sctx->clone_roots[i].found_refs) {
1251 if (!cur_clone_root)
1252 cur_clone_root = sctx->clone_roots + i;
1253 else if (sctx->clone_roots[i].root == sctx->send_root)
1254 /* prefer clones from send_root over others */
1255 cur_clone_root = sctx->clone_roots + i;
1256 break;
1257 }
1258
1259 }
1260
1261 if (cur_clone_root) {
1262 *found = cur_clone_root;
1263 ret = 0;
1264 } else {
1265 ret = -ENOENT;
1266 }
1267
1268 out:
1269 btrfs_free_path(tmp_path);
1270 return ret;
1271 }
1272
1273 static int read_symlink(struct send_ctx *sctx,
1274 struct btrfs_root *root,
1275 u64 ino,
1276 struct fs_path *dest)
1277 {
1278 int ret;
1279 struct btrfs_path *path;
1280 struct btrfs_key key;
1281 struct btrfs_file_extent_item *ei;
1282 u8 type;
1283 u8 compression;
1284 unsigned long off;
1285 int len;
1286
1287 path = alloc_path_for_send();
1288 if (!path)
1289 return -ENOMEM;
1290
1291 key.objectid = ino;
1292 key.type = BTRFS_EXTENT_DATA_KEY;
1293 key.offset = 0;
1294 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1295 if (ret < 0)
1296 goto out;
1297 BUG_ON(ret);
1298
1299 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
1300 struct btrfs_file_extent_item);
1301 type = btrfs_file_extent_type(path->nodes[0], ei);
1302 compression = btrfs_file_extent_compression(path->nodes[0], ei);
1303 BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
1304 BUG_ON(compression);
1305
1306 off = btrfs_file_extent_inline_start(ei);
1307 len = btrfs_file_extent_inline_len(path->nodes[0], ei);
1308
1309 ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
1310 if (ret < 0)
1311 goto out;
1312
1313 out:
1314 btrfs_free_path(path);
1315 return ret;
1316 }
1317
1318 /*
1319 * Helper function to generate a file name that is unique in the root of
1320 * send_root and parent_root. This is used to generate names for orphan inodes.
1321 */
1322 static int gen_unique_name(struct send_ctx *sctx,
1323 u64 ino, u64 gen,
1324 struct fs_path *dest)
1325 {
1326 int ret = 0;
1327 struct btrfs_path *path;
1328 struct btrfs_dir_item *di;
1329 char tmp[64];
1330 int len;
1331 u64 idx = 0;
1332
1333 path = alloc_path_for_send();
1334 if (!path)
1335 return -ENOMEM;
1336
1337 while (1) {
1338 len = snprintf(tmp, sizeof(tmp) - 1, "o%llu-%llu-%llu",
1339 ino, gen, idx);
1340 if (len >= sizeof(tmp)) {
1341 /* should really not happen */
1342 ret = -EOVERFLOW;
1343 goto out;
1344 }
1345
1346 di = btrfs_lookup_dir_item(NULL, sctx->send_root,
1347 path, BTRFS_FIRST_FREE_OBJECTID,
1348 tmp, strlen(tmp), 0);
1349 btrfs_release_path(path);
1350 if (IS_ERR(di)) {
1351 ret = PTR_ERR(di);
1352 goto out;
1353 }
1354 if (di) {
1355 /* not unique, try again */
1356 idx++;
1357 continue;
1358 }
1359
1360 if (!sctx->parent_root) {
1361 /* unique */
1362 ret = 0;
1363 break;
1364 }
1365
1366 di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
1367 path, BTRFS_FIRST_FREE_OBJECTID,
1368 tmp, strlen(tmp), 0);
1369 btrfs_release_path(path);
1370 if (IS_ERR(di)) {
1371 ret = PTR_ERR(di);
1372 goto out;
1373 }
1374 if (di) {
1375 /* not unique, try again */
1376 idx++;
1377 continue;
1378 }
1379 /* unique */
1380 break;
1381 }
1382
1383 ret = fs_path_add(dest, tmp, strlen(tmp));
1384
1385 out:
1386 btrfs_free_path(path);
1387 return ret;
1388 }
1389
1390 enum inode_state {
1391 inode_state_no_change,
1392 inode_state_will_create,
1393 inode_state_did_create,
1394 inode_state_will_delete,
1395 inode_state_did_delete,
1396 };
1397
1398 static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
1399 {
1400 int ret;
1401 int left_ret;
1402 int right_ret;
1403 u64 left_gen;
1404 u64 right_gen;
1405
1406 ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1407 NULL);
1408 if (ret < 0 && ret != -ENOENT)
1409 goto out;
1410 left_ret = ret;
1411
1412 if (!sctx->parent_root) {
1413 right_ret = -ENOENT;
1414 } else {
1415 ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1416 NULL, NULL, NULL);
1417 if (ret < 0 && ret != -ENOENT)
1418 goto out;
1419 right_ret = ret;
1420 }
1421
1422 if (!left_ret && !right_ret) {
1423 if (left_gen == gen && right_gen == gen)
1424 ret = inode_state_no_change;
1425 else if (left_gen == gen) {
1426 if (ino < sctx->send_progress)
1427 ret = inode_state_did_create;
1428 else
1429 ret = inode_state_will_create;
1430 } else if (right_gen == gen) {
1431 if (ino < sctx->send_progress)
1432 ret = inode_state_did_delete;
1433 else
1434 ret = inode_state_will_delete;
1435 } else {
1436 ret = -ENOENT;
1437 }
1438 } else if (!left_ret) {
1439 if (left_gen == gen) {
1440 if (ino < sctx->send_progress)
1441 ret = inode_state_did_create;
1442 else
1443 ret = inode_state_will_create;
1444 } else {
1445 ret = -ENOENT;
1446 }
1447 } else if (!right_ret) {
1448 if (right_gen == gen) {
1449 if (ino < sctx->send_progress)
1450 ret = inode_state_did_delete;
1451 else
1452 ret = inode_state_will_delete;
1453 } else {
1454 ret = -ENOENT;
1455 }
1456 } else {
1457 ret = -ENOENT;
1458 }
1459
1460 out:
1461 return ret;
1462 }
1463
1464 static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
1465 {
1466 int ret;
1467
1468 ret = get_cur_inode_state(sctx, ino, gen);
1469 if (ret < 0)
1470 goto out;
1471
1472 if (ret == inode_state_no_change ||
1473 ret == inode_state_did_create ||
1474 ret == inode_state_will_delete)
1475 ret = 1;
1476 else
1477 ret = 0;
1478
1479 out:
1480 return ret;
1481 }
1482
1483 /*
1484 * Helper function to lookup a dir item in a dir.
1485 */
1486 static int lookup_dir_item_inode(struct btrfs_root *root,
1487 u64 dir, const char *name, int name_len,
1488 u64 *found_inode,
1489 u8 *found_type)
1490 {
1491 int ret = 0;
1492 struct btrfs_dir_item *di;
1493 struct btrfs_key key;
1494 struct btrfs_path *path;
1495
1496 path = alloc_path_for_send();
1497 if (!path)
1498 return -ENOMEM;
1499
1500 di = btrfs_lookup_dir_item(NULL, root, path,
1501 dir, name, name_len, 0);
1502 if (!di) {
1503 ret = -ENOENT;
1504 goto out;
1505 }
1506 if (IS_ERR(di)) {
1507 ret = PTR_ERR(di);
1508 goto out;
1509 }
1510 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1511 *found_inode = key.objectid;
1512 *found_type = btrfs_dir_type(path->nodes[0], di);
1513
1514 out:
1515 btrfs_free_path(path);
1516 return ret;
1517 }
1518
1519 static int get_first_ref(struct send_ctx *sctx,
1520 struct btrfs_root *root, u64 ino,
1521 u64 *dir, u64 *dir_gen, struct fs_path *name)
1522 {
1523 int ret;
1524 struct btrfs_key key;
1525 struct btrfs_key found_key;
1526 struct btrfs_path *path;
1527 struct btrfs_inode_ref *iref;
1528 int len;
1529
1530 path = alloc_path_for_send();
1531 if (!path)
1532 return -ENOMEM;
1533
1534 key.objectid = ino;
1535 key.type = BTRFS_INODE_REF_KEY;
1536 key.offset = 0;
1537
1538 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
1539 if (ret < 0)
1540 goto out;
1541 if (!ret)
1542 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1543 path->slots[0]);
1544 if (ret || found_key.objectid != key.objectid ||
1545 found_key.type != key.type) {
1546 ret = -ENOENT;
1547 goto out;
1548 }
1549
1550 iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1551 struct btrfs_inode_ref);
1552 len = btrfs_inode_ref_name_len(path->nodes[0], iref);
1553 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1554 (unsigned long)(iref + 1), len);
1555 if (ret < 0)
1556 goto out;
1557 btrfs_release_path(path);
1558
1559 ret = get_inode_info(root, found_key.offset, NULL, dir_gen, NULL, NULL,
1560 NULL);
1561 if (ret < 0)
1562 goto out;
1563
1564 *dir = found_key.offset;
1565
1566 out:
1567 btrfs_free_path(path);
1568 return ret;
1569 }
1570
1571 static int is_first_ref(struct send_ctx *sctx,
1572 struct btrfs_root *root,
1573 u64 ino, u64 dir,
1574 const char *name, int name_len)
1575 {
1576 int ret;
1577 struct fs_path *tmp_name;
1578 u64 tmp_dir;
1579 u64 tmp_dir_gen;
1580
1581 tmp_name = fs_path_alloc(sctx);
1582 if (!tmp_name)
1583 return -ENOMEM;
1584
1585 ret = get_first_ref(sctx, root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
1586 if (ret < 0)
1587 goto out;
1588
1589 if (name_len != fs_path_len(tmp_name)) {
1590 ret = 0;
1591 goto out;
1592 }
1593
1594 ret = memcmp(tmp_name->start, name, name_len);
1595 if (ret)
1596 ret = 0;
1597 else
1598 ret = 1;
1599
1600 out:
1601 fs_path_free(sctx, tmp_name);
1602 return ret;
1603 }
1604
1605 static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
1606 const char *name, int name_len,
1607 u64 *who_ino, u64 *who_gen)
1608 {
1609 int ret = 0;
1610 u64 other_inode = 0;
1611 u8 other_type = 0;
1612
1613 if (!sctx->parent_root)
1614 goto out;
1615
1616 ret = is_inode_existent(sctx, dir, dir_gen);
1617 if (ret <= 0)
1618 goto out;
1619
1620 ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
1621 &other_inode, &other_type);
1622 if (ret < 0 && ret != -ENOENT)
1623 goto out;
1624 if (ret) {
1625 ret = 0;
1626 goto out;
1627 }
1628
1629 if (other_inode > sctx->send_progress) {
1630 ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1631 who_gen, NULL, NULL, NULL);
1632 if (ret < 0)
1633 goto out;
1634
1635 ret = 1;
1636 *who_ino = other_inode;
1637 } else {
1638 ret = 0;
1639 }
1640
1641 out:
1642 return ret;
1643 }
1644
1645 static int did_overwrite_ref(struct send_ctx *sctx,
1646 u64 dir, u64 dir_gen,
1647 u64 ino, u64 ino_gen,
1648 const char *name, int name_len)
1649 {
1650 int ret = 0;
1651 u64 gen;
1652 u64 ow_inode;
1653 u8 other_type;
1654
1655 if (!sctx->parent_root)
1656 goto out;
1657
1658 ret = is_inode_existent(sctx, dir, dir_gen);
1659 if (ret <= 0)
1660 goto out;
1661
1662 /* check if the ref was overwritten by another ref */
1663 ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
1664 &ow_inode, &other_type);
1665 if (ret < 0 && ret != -ENOENT)
1666 goto out;
1667 if (ret) {
1668 /* was never and will never be overwritten */
1669 ret = 0;
1670 goto out;
1671 }
1672
1673 ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1674 NULL);
1675 if (ret < 0)
1676 goto out;
1677
1678 if (ow_inode == ino && gen == ino_gen) {
1679 ret = 0;
1680 goto out;
1681 }
1682
1683 /* we know that it is or will be overwritten. check this now */
1684 if (ow_inode < sctx->send_progress)
1685 ret = 1;
1686 else
1687 ret = 0;
1688
1689 out:
1690 return ret;
1691 }
1692
1693 static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
1694 {
1695 int ret = 0;
1696 struct fs_path *name = NULL;
1697 u64 dir;
1698 u64 dir_gen;
1699
1700 if (!sctx->parent_root)
1701 goto out;
1702
1703 name = fs_path_alloc(sctx);
1704 if (!name)
1705 return -ENOMEM;
1706
1707 ret = get_first_ref(sctx, sctx->parent_root, ino, &dir, &dir_gen, name);
1708 if (ret < 0)
1709 goto out;
1710
1711 ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
1712 name->start, fs_path_len(name));
1713 if (ret < 0)
1714 goto out;
1715
1716 out:
1717 fs_path_free(sctx, name);
1718 return ret;
1719 }
1720
1721 static int name_cache_insert(struct send_ctx *sctx,
1722 struct name_cache_entry *nce)
1723 {
1724 int ret = 0;
1725 struct name_cache_entry **ncea;
1726
1727 ncea = radix_tree_lookup(&sctx->name_cache, nce->ino);
1728 if (ncea) {
1729 if (!ncea[0])
1730 ncea[0] = nce;
1731 else if (!ncea[1])
1732 ncea[1] = nce;
1733 else
1734 BUG();
1735 } else {
1736 ncea = kmalloc(sizeof(void *) * 2, GFP_NOFS);
1737 if (!ncea)
1738 return -ENOMEM;
1739
1740 ncea[0] = nce;
1741 ncea[1] = NULL;
1742 ret = radix_tree_insert(&sctx->name_cache, nce->ino, ncea);
1743 if (ret < 0)
1744 return ret;
1745 }
1746 list_add_tail(&nce->list, &sctx->name_cache_list);
1747 sctx->name_cache_size++;
1748
1749 return ret;
1750 }
1751
1752 static void name_cache_delete(struct send_ctx *sctx,
1753 struct name_cache_entry *nce)
1754 {
1755 struct name_cache_entry **ncea;
1756
1757 ncea = radix_tree_lookup(&sctx->name_cache, nce->ino);
1758 BUG_ON(!ncea);
1759
1760 if (ncea[0] == nce)
1761 ncea[0] = NULL;
1762 else if (ncea[1] == nce)
1763 ncea[1] = NULL;
1764 else
1765 BUG();
1766
1767 if (!ncea[0] && !ncea[1]) {
1768 radix_tree_delete(&sctx->name_cache, nce->ino);
1769 kfree(ncea);
1770 }
1771
1772 list_del(&nce->list);
1773
1774 sctx->name_cache_size--;
1775 }
1776
1777 static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
1778 u64 ino, u64 gen)
1779 {
1780 struct name_cache_entry **ncea;
1781
1782 ncea = radix_tree_lookup(&sctx->name_cache, ino);
1783 if (!ncea)
1784 return NULL;
1785
1786 if (ncea[0] && ncea[0]->gen == gen)
1787 return ncea[0];
1788 else if (ncea[1] && ncea[1]->gen == gen)
1789 return ncea[1];
1790 return NULL;
1791 }
1792
1793 static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
1794 {
1795 list_del(&nce->list);
1796 list_add_tail(&nce->list, &sctx->name_cache_list);
1797 }
1798
1799 static void name_cache_clean_unused(struct send_ctx *sctx)
1800 {
1801 struct name_cache_entry *nce;
1802
1803 if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
1804 return;
1805
1806 while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
1807 nce = list_entry(sctx->name_cache_list.next,
1808 struct name_cache_entry, list);
1809 name_cache_delete(sctx, nce);
1810 kfree(nce);
1811 }
1812 }
1813
1814 static void name_cache_free(struct send_ctx *sctx)
1815 {
1816 struct name_cache_entry *nce;
1817 struct name_cache_entry *tmp;
1818
1819 list_for_each_entry_safe(nce, tmp, &sctx->name_cache_list, list) {
1820 name_cache_delete(sctx, nce);
1821 }
1822 }
1823
1824 static int __get_cur_name_and_parent(struct send_ctx *sctx,
1825 u64 ino, u64 gen,
1826 u64 *parent_ino,
1827 u64 *parent_gen,
1828 struct fs_path *dest)
1829 {
1830 int ret;
1831 int nce_ret;
1832 struct btrfs_path *path = NULL;
1833 struct name_cache_entry *nce = NULL;
1834
1835 nce = name_cache_search(sctx, ino, gen);
1836 if (nce) {
1837 if (ino < sctx->send_progress && nce->need_later_update) {
1838 name_cache_delete(sctx, nce);
1839 kfree(nce);
1840 nce = NULL;
1841 } else {
1842 name_cache_used(sctx, nce);
1843 *parent_ino = nce->parent_ino;
1844 *parent_gen = nce->parent_gen;
1845 ret = fs_path_add(dest, nce->name, nce->name_len);
1846 if (ret < 0)
1847 goto out;
1848 ret = nce->ret;
1849 goto out;
1850 }
1851 }
1852
1853 path = alloc_path_for_send();
1854 if (!path)
1855 return -ENOMEM;
1856
1857 ret = is_inode_existent(sctx, ino, gen);
1858 if (ret < 0)
1859 goto out;
1860
1861 if (!ret) {
1862 ret = gen_unique_name(sctx, ino, gen, dest);
1863 if (ret < 0)
1864 goto out;
1865 ret = 1;
1866 goto out_cache;
1867 }
1868
1869 if (ino < sctx->send_progress)
1870 ret = get_first_ref(sctx, sctx->send_root, ino,
1871 parent_ino, parent_gen, dest);
1872 else
1873 ret = get_first_ref(sctx, sctx->parent_root, ino,
1874 parent_ino, parent_gen, dest);
1875 if (ret < 0)
1876 goto out;
1877
1878 ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
1879 dest->start, dest->end - dest->start);
1880 if (ret < 0)
1881 goto out;
1882 if (ret) {
1883 fs_path_reset(dest);
1884 ret = gen_unique_name(sctx, ino, gen, dest);
1885 if (ret < 0)
1886 goto out;
1887 ret = 1;
1888 }
1889
1890 out_cache:
1891 nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS);
1892 if (!nce) {
1893 ret = -ENOMEM;
1894 goto out;
1895 }
1896
1897 nce->ino = ino;
1898 nce->gen = gen;
1899 nce->parent_ino = *parent_ino;
1900 nce->parent_gen = *parent_gen;
1901 nce->name_len = fs_path_len(dest);
1902 nce->ret = ret;
1903 strcpy(nce->name, dest->start);
1904 memset(&nce->use_list, 0, sizeof(nce->use_list));
1905
1906 if (ino < sctx->send_progress)
1907 nce->need_later_update = 0;
1908 else
1909 nce->need_later_update = 1;
1910
1911 nce_ret = name_cache_insert(sctx, nce);
1912 if (nce_ret < 0)
1913 ret = nce_ret;
1914 name_cache_clean_unused(sctx);
1915
1916 out:
1917 btrfs_free_path(path);
1918 return ret;
1919 }
1920
1921 /*
1922 * Magic happens here. This function returns the first ref to an inode as it
1923 * would look like while receiving the stream at this point in time.
1924 * We walk the path up to the root. For every inode in between, we check if it
1925 * was already processed/sent. If yes, we continue with the parent as found
1926 * in send_root. If not, we continue with the parent as found in parent_root.
1927 * If we encounter an inode that was deleted at this point in time, we use the
1928 * inodes "orphan" name instead of the real name and stop. Same with new inodes
1929 * that were not created yet and overwritten inodes/refs.
1930 *
1931 * When do we have have orphan inodes:
1932 * 1. When an inode is freshly created and thus no valid refs are available yet
1933 * 2. When a directory lost all it's refs (deleted) but still has dir items
1934 * inside which were not processed yet (pending for move/delete). If anyone
1935 * tried to get the path to the dir items, it would get a path inside that
1936 * orphan directory.
1937 * 3. When an inode is moved around or gets new links, it may overwrite the ref
1938 * of an unprocessed inode. If in that case the first ref would be
1939 * overwritten, the overwritten inode gets "orphanized". Later when we
1940 * process this overwritten inode, it is restored at a new place by moving
1941 * the orphan inode.
1942 *
1943 * sctx->send_progress tells this function at which point in time receiving
1944 * would be.
1945 */
1946 static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
1947 struct fs_path *dest)
1948 {
1949 int ret = 0;
1950 struct fs_path *name = NULL;
1951 u64 parent_inode = 0;
1952 u64 parent_gen = 0;
1953 int stop = 0;
1954
1955 name = fs_path_alloc(sctx);
1956 if (!name) {
1957 ret = -ENOMEM;
1958 goto out;
1959 }
1960
1961 dest->reversed = 1;
1962 fs_path_reset(dest);
1963
1964 while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
1965 fs_path_reset(name);
1966
1967 ret = __get_cur_name_and_parent(sctx, ino, gen,
1968 &parent_inode, &parent_gen, name);
1969 if (ret < 0)
1970 goto out;
1971 if (ret)
1972 stop = 1;
1973
1974 ret = fs_path_add_path(dest, name);
1975 if (ret < 0)
1976 goto out;
1977
1978 ino = parent_inode;
1979 gen = parent_gen;
1980 }
1981
1982 out:
1983 fs_path_free(sctx, name);
1984 if (!ret)
1985 fs_path_unreverse(dest);
1986 return ret;
1987 }
1988
1989 /*
1990 * Called for regular files when sending extents data. Opens a struct file
1991 * to read from the file.
1992 */
1993 static int open_cur_inode_file(struct send_ctx *sctx)
1994 {
1995 int ret = 0;
1996 struct btrfs_key key;
1997 struct path path;
1998 struct inode *inode;
1999 struct dentry *dentry;
2000 struct file *filp;
2001 int new = 0;
2002
2003 if (sctx->cur_inode_filp)
2004 goto out;
2005
2006 key.objectid = sctx->cur_ino;
2007 key.type = BTRFS_INODE_ITEM_KEY;
2008 key.offset = 0;
2009
2010 inode = btrfs_iget(sctx->send_root->fs_info->sb, &key, sctx->send_root,
2011 &new);
2012 if (IS_ERR(inode)) {
2013 ret = PTR_ERR(inode);
2014 goto out;
2015 }
2016
2017 dentry = d_obtain_alias(inode);
2018 inode = NULL;
2019 if (IS_ERR(dentry)) {
2020 ret = PTR_ERR(dentry);
2021 goto out;
2022 }
2023
2024 path.mnt = sctx->mnt;
2025 path.dentry = dentry;
2026 filp = dentry_open(&path, O_RDONLY | O_LARGEFILE, current_cred());
2027 dput(dentry);
2028 dentry = NULL;
2029 if (IS_ERR(filp)) {
2030 ret = PTR_ERR(filp);
2031 goto out;
2032 }
2033 sctx->cur_inode_filp = filp;
2034
2035 out:
2036 /*
2037 * no xxxput required here as every vfs op
2038 * does it by itself on failure
2039 */
2040 return ret;
2041 }
2042
2043 /*
2044 * Closes the struct file that was created in open_cur_inode_file
2045 */
2046 static int close_cur_inode_file(struct send_ctx *sctx)
2047 {
2048 int ret = 0;
2049
2050 if (!sctx->cur_inode_filp)
2051 goto out;
2052
2053 ret = filp_close(sctx->cur_inode_filp, NULL);
2054 sctx->cur_inode_filp = NULL;
2055
2056 out:
2057 return ret;
2058 }
2059
2060 /*
2061 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2062 */
2063 static int send_subvol_begin(struct send_ctx *sctx)
2064 {
2065 int ret;
2066 struct btrfs_root *send_root = sctx->send_root;
2067 struct btrfs_root *parent_root = sctx->parent_root;
2068 struct btrfs_path *path;
2069 struct btrfs_key key;
2070 struct btrfs_root_ref *ref;
2071 struct extent_buffer *leaf;
2072 char *name = NULL;
2073 int namelen;
2074
2075 path = alloc_path_for_send();
2076 if (!path)
2077 return -ENOMEM;
2078
2079 name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS);
2080 if (!name) {
2081 btrfs_free_path(path);
2082 return -ENOMEM;
2083 }
2084
2085 key.objectid = send_root->objectid;
2086 key.type = BTRFS_ROOT_BACKREF_KEY;
2087 key.offset = 0;
2088
2089 ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
2090 &key, path, 1, 0);
2091 if (ret < 0)
2092 goto out;
2093 if (ret) {
2094 ret = -ENOENT;
2095 goto out;
2096 }
2097
2098 leaf = path->nodes[0];
2099 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2100 if (key.type != BTRFS_ROOT_BACKREF_KEY ||
2101 key.objectid != send_root->objectid) {
2102 ret = -ENOENT;
2103 goto out;
2104 }
2105 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
2106 namelen = btrfs_root_ref_name_len(leaf, ref);
2107 read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
2108 btrfs_release_path(path);
2109
2110 if (ret < 0)
2111 goto out;
2112
2113 if (parent_root) {
2114 ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
2115 if (ret < 0)
2116 goto out;
2117 } else {
2118 ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
2119 if (ret < 0)
2120 goto out;
2121 }
2122
2123 TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
2124 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2125 sctx->send_root->root_item.uuid);
2126 TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2127 sctx->send_root->root_item.ctransid);
2128 if (parent_root) {
2129 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2130 sctx->parent_root->root_item.uuid);
2131 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2132 sctx->parent_root->root_item.ctransid);
2133 }
2134
2135 ret = send_cmd(sctx);
2136
2137 tlv_put_failure:
2138 out:
2139 btrfs_free_path(path);
2140 kfree(name);
2141 return ret;
2142 }
2143
2144 static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
2145 {
2146 int ret = 0;
2147 struct fs_path *p;
2148
2149 verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino, size);
2150
2151 p = fs_path_alloc(sctx);
2152 if (!p)
2153 return -ENOMEM;
2154
2155 ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
2156 if (ret < 0)
2157 goto out;
2158
2159 ret = get_cur_path(sctx, ino, gen, p);
2160 if (ret < 0)
2161 goto out;
2162 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2163 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
2164
2165 ret = send_cmd(sctx);
2166
2167 tlv_put_failure:
2168 out:
2169 fs_path_free(sctx, p);
2170 return ret;
2171 }
2172
2173 static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
2174 {
2175 int ret = 0;
2176 struct fs_path *p;
2177
2178 verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino, mode);
2179
2180 p = fs_path_alloc(sctx);
2181 if (!p)
2182 return -ENOMEM;
2183
2184 ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
2185 if (ret < 0)
2186 goto out;
2187
2188 ret = get_cur_path(sctx, ino, gen, p);
2189 if (ret < 0)
2190 goto out;
2191 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2192 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
2193
2194 ret = send_cmd(sctx);
2195
2196 tlv_put_failure:
2197 out:
2198 fs_path_free(sctx, p);
2199 return ret;
2200 }
2201
2202 static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
2203 {
2204 int ret = 0;
2205 struct fs_path *p;
2206
2207 verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino, uid, gid);
2208
2209 p = fs_path_alloc(sctx);
2210 if (!p)
2211 return -ENOMEM;
2212
2213 ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
2214 if (ret < 0)
2215 goto out;
2216
2217 ret = get_cur_path(sctx, ino, gen, p);
2218 if (ret < 0)
2219 goto out;
2220 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2221 TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
2222 TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
2223
2224 ret = send_cmd(sctx);
2225
2226 tlv_put_failure:
2227 out:
2228 fs_path_free(sctx, p);
2229 return ret;
2230 }
2231
2232 static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
2233 {
2234 int ret = 0;
2235 struct fs_path *p = NULL;
2236 struct btrfs_inode_item *ii;
2237 struct btrfs_path *path = NULL;
2238 struct extent_buffer *eb;
2239 struct btrfs_key key;
2240 int slot;
2241
2242 verbose_printk("btrfs: send_utimes %llu\n", ino);
2243
2244 p = fs_path_alloc(sctx);
2245 if (!p)
2246 return -ENOMEM;
2247
2248 path = alloc_path_for_send();
2249 if (!path) {
2250 ret = -ENOMEM;
2251 goto out;
2252 }
2253
2254 key.objectid = ino;
2255 key.type = BTRFS_INODE_ITEM_KEY;
2256 key.offset = 0;
2257 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2258 if (ret < 0)
2259 goto out;
2260
2261 eb = path->nodes[0];
2262 slot = path->slots[0];
2263 ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2264
2265 ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
2266 if (ret < 0)
2267 goto out;
2268
2269 ret = get_cur_path(sctx, ino, gen, p);
2270 if (ret < 0)
2271 goto out;
2272 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2273 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb,
2274 btrfs_inode_atime(ii));
2275 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb,
2276 btrfs_inode_mtime(ii));
2277 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb,
2278 btrfs_inode_ctime(ii));
2279 /* TODO otime? */
2280
2281 ret = send_cmd(sctx);
2282
2283 tlv_put_failure:
2284 out:
2285 fs_path_free(sctx, p);
2286 btrfs_free_path(path);
2287 return ret;
2288 }
2289
2290 /*
2291 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2292 * a valid path yet because we did not process the refs yet. So, the inode
2293 * is created as orphan.
2294 */
2295 static int send_create_inode(struct send_ctx *sctx, struct btrfs_path *path,
2296 struct btrfs_key *key)
2297 {
2298 int ret = 0;
2299 struct extent_buffer *eb = path->nodes[0];
2300 struct btrfs_inode_item *ii;
2301 struct fs_path *p;
2302 int slot = path->slots[0];
2303 int cmd;
2304 u64 mode;
2305
2306 verbose_printk("btrfs: send_create_inode %llu\n", sctx->cur_ino);
2307
2308 p = fs_path_alloc(sctx);
2309 if (!p)
2310 return -ENOMEM;
2311
2312 ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2313 mode = btrfs_inode_mode(eb, ii);
2314
2315 if (S_ISREG(mode))
2316 cmd = BTRFS_SEND_C_MKFILE;
2317 else if (S_ISDIR(mode))
2318 cmd = BTRFS_SEND_C_MKDIR;
2319 else if (S_ISLNK(mode))
2320 cmd = BTRFS_SEND_C_SYMLINK;
2321 else if (S_ISCHR(mode) || S_ISBLK(mode))
2322 cmd = BTRFS_SEND_C_MKNOD;
2323 else if (S_ISFIFO(mode))
2324 cmd = BTRFS_SEND_C_MKFIFO;
2325 else if (S_ISSOCK(mode))
2326 cmd = BTRFS_SEND_C_MKSOCK;
2327 else {
2328 printk(KERN_WARNING "btrfs: unexpected inode type %o",
2329 (int)(mode & S_IFMT));
2330 ret = -ENOTSUPP;
2331 goto out;
2332 }
2333
2334 ret = begin_cmd(sctx, cmd);
2335 if (ret < 0)
2336 goto out;
2337
2338 ret = gen_unique_name(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
2339 if (ret < 0)
2340 goto out;
2341
2342 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2343 TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, sctx->cur_ino);
2344
2345 if (S_ISLNK(mode)) {
2346 fs_path_reset(p);
2347 ret = read_symlink(sctx, sctx->send_root, sctx->cur_ino, p);
2348 if (ret < 0)
2349 goto out;
2350 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
2351 } else if (S_ISCHR(mode) || S_ISBLK(mode) ||
2352 S_ISFIFO(mode) || S_ISSOCK(mode)) {
2353 TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, btrfs_inode_rdev(eb, ii));
2354 }
2355
2356 ret = send_cmd(sctx);
2357 if (ret < 0)
2358 goto out;
2359
2360
2361 tlv_put_failure:
2362 out:
2363 fs_path_free(sctx, p);
2364 return ret;
2365 }
2366
2367 struct recorded_ref {
2368 struct list_head list;
2369 char *dir_path;
2370 char *name;
2371 struct fs_path *full_path;
2372 u64 dir;
2373 u64 dir_gen;
2374 int dir_path_len;
2375 int name_len;
2376 };
2377
2378 /*
2379 * We need to process new refs before deleted refs, but compare_tree gives us
2380 * everything mixed. So we first record all refs and later process them.
2381 * This function is a helper to record one ref.
2382 */
2383 static int record_ref(struct list_head *head, u64 dir,
2384 u64 dir_gen, struct fs_path *path)
2385 {
2386 struct recorded_ref *ref;
2387 char *tmp;
2388
2389 ref = kmalloc(sizeof(*ref), GFP_NOFS);
2390 if (!ref)
2391 return -ENOMEM;
2392
2393 ref->dir = dir;
2394 ref->dir_gen = dir_gen;
2395 ref->full_path = path;
2396
2397 tmp = strrchr(ref->full_path->start, '/');
2398 if (!tmp) {
2399 ref->name_len = ref->full_path->end - ref->full_path->start;
2400 ref->name = ref->full_path->start;
2401 ref->dir_path_len = 0;
2402 ref->dir_path = ref->full_path->start;
2403 } else {
2404 tmp++;
2405 ref->name_len = ref->full_path->end - tmp;
2406 ref->name = tmp;
2407 ref->dir_path = ref->full_path->start;
2408 ref->dir_path_len = ref->full_path->end -
2409 ref->full_path->start - 1 - ref->name_len;
2410 }
2411
2412 list_add_tail(&ref->list, head);
2413 return 0;
2414 }
2415
2416 static void __free_recorded_refs(struct send_ctx *sctx, struct list_head *head)
2417 {
2418 struct recorded_ref *cur;
2419 struct recorded_ref *tmp;
2420
2421 list_for_each_entry_safe(cur, tmp, head, list) {
2422 fs_path_free(sctx, cur->full_path);
2423 kfree(cur);
2424 }
2425 INIT_LIST_HEAD(head);
2426 }
2427
2428 static void free_recorded_refs(struct send_ctx *sctx)
2429 {
2430 __free_recorded_refs(sctx, &sctx->new_refs);
2431 __free_recorded_refs(sctx, &sctx->deleted_refs);
2432 }
2433
2434 /*
2435 * Renames/moves a file/dir to it's orphan name. Used when the first
2436 * ref of an unprocessed inode gets overwritten and for all non empty
2437 * directories.
2438 */
2439 static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
2440 struct fs_path *path)
2441 {
2442 int ret;
2443 struct fs_path *orphan;
2444
2445 orphan = fs_path_alloc(sctx);
2446 if (!orphan)
2447 return -ENOMEM;
2448
2449 ret = gen_unique_name(sctx, ino, gen, orphan);
2450 if (ret < 0)
2451 goto out;
2452
2453 ret = send_rename(sctx, path, orphan);
2454
2455 out:
2456 fs_path_free(sctx, orphan);
2457 return ret;
2458 }
2459
2460 /*
2461 * Returns 1 if a directory can be removed at this point in time.
2462 * We check this by iterating all dir items and checking if the inode behind
2463 * the dir item was already processed.
2464 */
2465 static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 send_progress)
2466 {
2467 int ret = 0;
2468 struct btrfs_root *root = sctx->parent_root;
2469 struct btrfs_path *path;
2470 struct btrfs_key key;
2471 struct btrfs_key found_key;
2472 struct btrfs_key loc;
2473 struct btrfs_dir_item *di;
2474
2475 path = alloc_path_for_send();
2476 if (!path)
2477 return -ENOMEM;
2478
2479 key.objectid = dir;
2480 key.type = BTRFS_DIR_INDEX_KEY;
2481 key.offset = 0;
2482
2483 while (1) {
2484 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
2485 if (ret < 0)
2486 goto out;
2487 if (!ret) {
2488 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2489 path->slots[0]);
2490 }
2491 if (ret || found_key.objectid != key.objectid ||
2492 found_key.type != key.type) {
2493 break;
2494 }
2495
2496 di = btrfs_item_ptr(path->nodes[0], path->slots[0],
2497 struct btrfs_dir_item);
2498 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
2499
2500 if (loc.objectid > send_progress) {
2501 ret = 0;
2502 goto out;
2503 }
2504
2505 btrfs_release_path(path);
2506 key.offset = found_key.offset + 1;
2507 }
2508
2509 ret = 1;
2510
2511 out:
2512 btrfs_free_path(path);
2513 return ret;
2514 }
2515
2516 struct finish_unordered_dir_ctx {
2517 struct send_ctx *sctx;
2518 struct fs_path *cur_path;
2519 struct fs_path *dir_path;
2520 u64 dir_ino;
2521 int need_delete;
2522 int delete_pass;
2523 };
2524
2525 int __finish_unordered_dir(int num, struct btrfs_key *di_key,
2526 const char *name, int name_len,
2527 const char *data, int data_len,
2528 u8 type, void *ctx)
2529 {
2530 int ret = 0;
2531 struct finish_unordered_dir_ctx *fctx = ctx;
2532 struct send_ctx *sctx = fctx->sctx;
2533 u64 di_gen;
2534 u64 di_mode;
2535 int is_orphan = 0;
2536
2537 if (di_key->objectid >= fctx->dir_ino)
2538 goto out;
2539
2540 fs_path_reset(fctx->cur_path);
2541
2542 ret = get_inode_info(sctx->send_root, di_key->objectid,
2543 NULL, &di_gen, &di_mode, NULL, NULL);
2544 if (ret < 0)
2545 goto out;
2546
2547 ret = is_first_ref(sctx, sctx->send_root, di_key->objectid,
2548 fctx->dir_ino, name, name_len);
2549 if (ret < 0)
2550 goto out;
2551 if (ret) {
2552 is_orphan = 1;
2553 ret = gen_unique_name(sctx, di_key->objectid, di_gen,
2554 fctx->cur_path);
2555 } else {
2556 ret = get_cur_path(sctx, di_key->objectid, di_gen,
2557 fctx->cur_path);
2558 }
2559 if (ret < 0)
2560 goto out;
2561
2562 ret = fs_path_add(fctx->dir_path, name, name_len);
2563 if (ret < 0)
2564 goto out;
2565
2566 if (!fctx->delete_pass) {
2567 if (S_ISDIR(di_mode)) {
2568 ret = send_rename(sctx, fctx->cur_path,
2569 fctx->dir_path);
2570 } else {
2571 ret = send_link(sctx, fctx->dir_path,
2572 fctx->cur_path);
2573 if (is_orphan)
2574 fctx->need_delete = 1;
2575 }
2576 } else if (!S_ISDIR(di_mode)) {
2577 ret = send_unlink(sctx, fctx->cur_path);
2578 } else {
2579 ret = 0;
2580 }
2581
2582 fs_path_remove(fctx->dir_path);
2583
2584 out:
2585 return ret;
2586 }
2587
2588 /*
2589 * Go through all dir items and see if we find refs which could not be created
2590 * in the past because the dir did not exist at that time.
2591 */
2592 static int finish_outoforder_dir(struct send_ctx *sctx, u64 dir, u64 dir_gen)
2593 {
2594 int ret = 0;
2595 struct btrfs_path *path = NULL;
2596 struct btrfs_key key;
2597 struct btrfs_key found_key;
2598 struct extent_buffer *eb;
2599 struct finish_unordered_dir_ctx fctx;
2600 int slot;
2601
2602 path = alloc_path_for_send();
2603 if (!path) {
2604 ret = -ENOMEM;
2605 goto out;
2606 }
2607
2608 memset(&fctx, 0, sizeof(fctx));
2609 fctx.sctx = sctx;
2610 fctx.cur_path = fs_path_alloc(sctx);
2611 fctx.dir_path = fs_path_alloc(sctx);
2612 if (!fctx.cur_path || !fctx.dir_path) {
2613 ret = -ENOMEM;
2614 goto out;
2615 }
2616 fctx.dir_ino = dir;
2617
2618 ret = get_cur_path(sctx, dir, dir_gen, fctx.dir_path);
2619 if (ret < 0)
2620 goto out;
2621
2622 /*
2623 * We do two passes. The first links in the new refs and the second
2624 * deletes orphans if required. Deletion of orphans is not required for
2625 * directory inodes, as we always have only one ref and use rename
2626 * instead of link for those.
2627 */
2628
2629 again:
2630 key.objectid = dir;
2631 key.type = BTRFS_DIR_ITEM_KEY;
2632 key.offset = 0;
2633 while (1) {
2634 ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
2635 1, 0);
2636 if (ret < 0)
2637 goto out;
2638 eb = path->nodes[0];
2639 slot = path->slots[0];
2640 btrfs_item_key_to_cpu(eb, &found_key, slot);
2641
2642 if (found_key.objectid != key.objectid ||
2643 found_key.type != key.type) {
2644 btrfs_release_path(path);
2645 break;
2646 }
2647
2648 ret = iterate_dir_item(sctx, sctx->send_root, path,
2649 &found_key, __finish_unordered_dir,
2650 &fctx);
2651 if (ret < 0)
2652 goto out;
2653
2654 key.offset = found_key.offset + 1;
2655 btrfs_release_path(path);
2656 }
2657
2658 if (!fctx.delete_pass && fctx.need_delete) {
2659 fctx.delete_pass = 1;
2660 goto again;
2661 }
2662
2663 out:
2664 btrfs_free_path(path);
2665 fs_path_free(sctx, fctx.cur_path);
2666 fs_path_free(sctx, fctx.dir_path);
2667 return ret;
2668 }
2669
2670 /*
2671 * This does all the move/link/unlink/rmdir magic.
2672 */
2673 static int process_recorded_refs(struct send_ctx *sctx)
2674 {
2675 int ret = 0;
2676 struct recorded_ref *cur;
2677 struct ulist *check_dirs = NULL;
2678 struct ulist_iterator uit;
2679 struct ulist_node *un;
2680 struct fs_path *valid_path = NULL;
2681 u64 ow_inode = 0;
2682 u64 ow_gen;
2683 int did_overwrite = 0;
2684 int is_orphan = 0;
2685
2686 verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
2687
2688 valid_path = fs_path_alloc(sctx);
2689 if (!valid_path) {
2690 ret = -ENOMEM;
2691 goto out;
2692 }
2693
2694 check_dirs = ulist_alloc(GFP_NOFS);
2695 if (!check_dirs) {
2696 ret = -ENOMEM;
2697 goto out;
2698 }
2699
2700 /*
2701 * First, check if the first ref of the current inode was overwritten
2702 * before. If yes, we know that the current inode was already orphanized
2703 * and thus use the orphan name. If not, we can use get_cur_path to
2704 * get the path of the first ref as it would like while receiving at
2705 * this point in time.
2706 * New inodes are always orphan at the beginning, so force to use the
2707 * orphan name in this case.
2708 * The first ref is stored in valid_path and will be updated if it
2709 * gets moved around.
2710 */
2711 if (!sctx->cur_inode_new) {
2712 ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
2713 sctx->cur_inode_gen);
2714 if (ret < 0)
2715 goto out;
2716 if (ret)
2717 did_overwrite = 1;
2718 }
2719 if (sctx->cur_inode_new || did_overwrite) {
2720 ret = gen_unique_name(sctx, sctx->cur_ino,
2721 sctx->cur_inode_gen, valid_path);
2722 if (ret < 0)
2723 goto out;
2724 is_orphan = 1;
2725 } else {
2726 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
2727 valid_path);
2728 if (ret < 0)
2729 goto out;
2730 }
2731
2732 list_for_each_entry(cur, &sctx->new_refs, list) {
2733 /*
2734 * Check if this new ref would overwrite the first ref of
2735 * another unprocessed inode. If yes, orphanize the
2736 * overwritten inode. If we find an overwritten ref that is
2737 * not the first ref, simply unlink it.
2738 */
2739 ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
2740 cur->name, cur->name_len,
2741 &ow_inode, &ow_gen);
2742 if (ret < 0)
2743 goto out;
2744 if (ret) {
2745 ret = is_first_ref(sctx, sctx->parent_root,
2746 ow_inode, cur->dir, cur->name,
2747 cur->name_len);
2748 if (ret < 0)
2749 goto out;
2750 if (ret) {
2751 ret = orphanize_inode(sctx, ow_inode, ow_gen,
2752 cur->full_path);
2753 if (ret < 0)
2754 goto out;
2755 } else {
2756 ret = send_unlink(sctx, cur->full_path);
2757 if (ret < 0)
2758 goto out;
2759 }
2760 }
2761
2762 /*
2763 * link/move the ref to the new place. If we have an orphan
2764 * inode, move it and update valid_path. If not, link or move
2765 * it depending on the inode mode.
2766 */
2767 if (is_orphan && !sctx->cur_inode_first_ref_orphan) {
2768 ret = send_rename(sctx, valid_path, cur->full_path);
2769 if (ret < 0)
2770 goto out;
2771 is_orphan = 0;
2772 ret = fs_path_copy(valid_path, cur->full_path);
2773 if (ret < 0)
2774 goto out;
2775 } else {
2776 if (S_ISDIR(sctx->cur_inode_mode)) {
2777 /*
2778 * Dirs can't be linked, so move it. For moved
2779 * dirs, we always have one new and one deleted
2780 * ref. The deleted ref is ignored later.
2781 */
2782 ret = send_rename(sctx, valid_path,
2783 cur->full_path);
2784 if (ret < 0)
2785 goto out;
2786 ret = fs_path_copy(valid_path, cur->full_path);
2787 if (ret < 0)
2788 goto out;
2789 } else {
2790 ret = send_link(sctx, cur->full_path,
2791 valid_path);
2792 if (ret < 0)
2793 goto out;
2794 }
2795 }
2796 ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
2797 GFP_NOFS);
2798 if (ret < 0)
2799 goto out;
2800 }
2801
2802 if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
2803 /*
2804 * Check if we can already rmdir the directory. If not,
2805 * orphanize it. For every dir item inside that gets deleted
2806 * later, we do this check again and rmdir it then if possible.
2807 * See the use of check_dirs for more details.
2808 */
2809 ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_ino);
2810 if (ret < 0)
2811 goto out;
2812 if (ret) {
2813 ret = send_rmdir(sctx, valid_path);
2814 if (ret < 0)
2815 goto out;
2816 } else if (!is_orphan) {
2817 ret = orphanize_inode(sctx, sctx->cur_ino,
2818 sctx->cur_inode_gen, valid_path);
2819 if (ret < 0)
2820 goto out;
2821 is_orphan = 1;
2822 }
2823
2824 list_for_each_entry(cur, &sctx->deleted_refs, list) {
2825 ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
2826 GFP_NOFS);
2827 if (ret < 0)
2828 goto out;
2829 }
2830 } else if (!S_ISDIR(sctx->cur_inode_mode)) {
2831 /*
2832 * We have a non dir inode. Go through all deleted refs and
2833 * unlink them if they were not already overwritten by other
2834 * inodes.
2835 */
2836 list_for_each_entry(cur, &sctx->deleted_refs, list) {
2837 ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
2838 sctx->cur_ino, sctx->cur_inode_gen,
2839 cur->name, cur->name_len);
2840 if (ret < 0)
2841 goto out;
2842 if (!ret) {
2843 /*
2844 * In case the inode was moved to a directory
2845 * that was not created yet (see
2846 * __record_new_ref), we can not unlink the ref
2847 * as it will be needed later when the parent
2848 * directory is created, so that we can move in
2849 * the inode to the new dir.
2850 */
2851 if (!is_orphan &&
2852 sctx->cur_inode_first_ref_orphan) {
2853 ret = orphanize_inode(sctx,
2854 sctx->cur_ino,
2855 sctx->cur_inode_gen,
2856 cur->full_path);
2857 if (ret < 0)
2858 goto out;
2859 ret = gen_unique_name(sctx,
2860 sctx->cur_ino,
2861 sctx->cur_inode_gen,
2862 valid_path);
2863 if (ret < 0)
2864 goto out;
2865 is_orphan = 1;
2866
2867 } else {
2868 ret = send_unlink(sctx, cur->full_path);
2869 if (ret < 0)
2870 goto out;
2871 }
2872 }
2873 ret = ulist_add(check_dirs, cur->dir, cur->dir_gen,
2874 GFP_NOFS);
2875 if (ret < 0)
2876 goto out;
2877 }
2878
2879 /*
2880 * If the inode is still orphan, unlink the orphan. This may
2881 * happen when a previous inode did overwrite the first ref
2882 * of this inode and no new refs were added for the current
2883 * inode.
2884 * We can however not delete the orphan in case the inode relies
2885 * in a directory that was not created yet (see
2886 * __record_new_ref)
2887 */
2888 if (is_orphan && !sctx->cur_inode_first_ref_orphan) {
2889 ret = send_unlink(sctx, valid_path);
2890 if (ret < 0)
2891 goto out;
2892 }
2893 }
2894
2895 /*
2896 * We did collect all parent dirs where cur_inode was once located. We
2897 * now go through all these dirs and check if they are pending for
2898 * deletion and if it's finally possible to perform the rmdir now.
2899 * We also update the inode stats of the parent dirs here.
2900 */
2901 ULIST_ITER_INIT(&uit);
2902 while ((un = ulist_next(check_dirs, &uit))) {
2903 if (un->val > sctx->cur_ino)
2904 continue;
2905
2906 ret = get_cur_inode_state(sctx, un->val, un->aux);
2907 if (ret < 0)
2908 goto out;
2909
2910 if (ret == inode_state_did_create ||
2911 ret == inode_state_no_change) {
2912 /* TODO delayed utimes */
2913 ret = send_utimes(sctx, un->val, un->aux);
2914 if (ret < 0)
2915 goto out;
2916 } else if (ret == inode_state_did_delete) {
2917 ret = can_rmdir(sctx, un->val, sctx->cur_ino);
2918 if (ret < 0)
2919 goto out;
2920 if (ret) {
2921 ret = get_cur_path(sctx, un->val, un->aux,
2922 valid_path);
2923 if (ret < 0)
2924 goto out;
2925 ret = send_rmdir(sctx, valid_path);
2926 if (ret < 0)
2927 goto out;
2928 }
2929 }
2930 }
2931
2932 /*
2933 * Current inode is now at it's new position, so we must increase
2934 * send_progress
2935 */
2936 sctx->send_progress = sctx->cur_ino + 1;
2937
2938 /*
2939 * We may have a directory here that has pending refs which could not
2940 * be created before (because the dir did not exist before, see
2941 * __record_new_ref). finish_outoforder_dir will link/move the pending
2942 * refs.
2943 */
2944 if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_new) {
2945 ret = finish_outoforder_dir(sctx, sctx->cur_ino,
2946 sctx->cur_inode_gen);
2947 if (ret < 0)
2948 goto out;
2949 }
2950
2951 ret = 0;
2952
2953 out:
2954 free_recorded_refs(sctx);
2955 ulist_free(check_dirs);
2956 fs_path_free(sctx, valid_path);
2957 return ret;
2958 }
2959
2960 static int __record_new_ref(int num, u64 dir, int index,
2961 struct fs_path *name,
2962 void *ctx)
2963 {
2964 int ret = 0;
2965 struct send_ctx *sctx = ctx;
2966 struct fs_path *p;
2967 u64 gen;
2968
2969 p = fs_path_alloc(sctx);
2970 if (!p)
2971 return -ENOMEM;
2972
2973 ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL, NULL,
2974 NULL);
2975 if (ret < 0)
2976 goto out;
2977
2978 /*
2979 * The parent may be non-existent at this point in time. This happens
2980 * if the ino of the parent dir is higher then the current ino. In this
2981 * case, we can not process this ref until the parent dir is finally
2982 * created. If we reach the parent dir later, process_recorded_refs
2983 * will go through all dir items and process the refs that could not be
2984 * processed before. In case this is the first ref, we set
2985 * cur_inode_first_ref_orphan to 1 to inform process_recorded_refs to
2986 * keep an orphan of the inode so that it later can be used for
2987 * link/move
2988 */
2989 ret = is_inode_existent(sctx, dir, gen);
2990 if (ret < 0)
2991 goto out;
2992 if (!ret) {
2993 ret = is_first_ref(sctx, sctx->send_root, sctx->cur_ino, dir,
2994 name->start, fs_path_len(name));
2995 if (ret < 0)
2996 goto out;
2997 if (ret)
2998 sctx->cur_inode_first_ref_orphan = 1;
2999 ret = 0;
3000 goto out;
3001 }
3002
3003 ret = get_cur_path(sctx, dir, gen, p);
3004 if (ret < 0)
3005 goto out;
3006 ret = fs_path_add_path(p, name);
3007 if (ret < 0)
3008 goto out;
3009
3010 ret = record_ref(&sctx->new_refs, dir, gen, p);
3011
3012 out:
3013 if (ret)
3014 fs_path_free(sctx, p);
3015 return ret;
3016 }
3017
3018 static int __record_deleted_ref(int num, u64 dir, int index,
3019 struct fs_path *name,
3020 void *ctx)
3021 {
3022 int ret = 0;
3023 struct send_ctx *sctx = ctx;
3024 struct fs_path *p;
3025 u64 gen;
3026
3027 p = fs_path_alloc(sctx);
3028 if (!p)
3029 return -ENOMEM;
3030
3031 ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL, NULL,
3032 NULL);
3033 if (ret < 0)
3034 goto out;
3035
3036 ret = get_cur_path(sctx, dir, gen, p);
3037 if (ret < 0)
3038 goto out;
3039 ret = fs_path_add_path(p, name);
3040 if (ret < 0)
3041 goto out;
3042
3043 ret = record_ref(&sctx->deleted_refs, dir, gen, p);
3044
3045 out:
3046 if (ret)
3047 fs_path_free(sctx, p);
3048 return ret;
3049 }
3050
3051 static int record_new_ref(struct send_ctx *sctx)
3052 {
3053 int ret;
3054
3055 ret = iterate_inode_ref(sctx, sctx->send_root, sctx->left_path,
3056 sctx->cmp_key, 0, __record_new_ref, sctx);
3057 if (ret < 0)
3058 goto out;
3059 ret = 0;
3060
3061 out:
3062 return ret;
3063 }
3064
3065 static int record_deleted_ref(struct send_ctx *sctx)
3066 {
3067 int ret;
3068
3069 ret = iterate_inode_ref(sctx, sctx->parent_root, sctx->right_path,
3070 sctx->cmp_key, 0, __record_deleted_ref, sctx);
3071 if (ret < 0)
3072 goto out;
3073 ret = 0;
3074
3075 out:
3076 return ret;
3077 }
3078
3079 struct find_ref_ctx {
3080 u64 dir;
3081 struct fs_path *name;
3082 int found_idx;
3083 };
3084
3085 static int __find_iref(int num, u64 dir, int index,
3086 struct fs_path *name,
3087 void *ctx_)
3088 {
3089 struct find_ref_ctx *ctx = ctx_;
3090
3091 if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
3092 strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
3093 ctx->found_idx = num;
3094 return 1;
3095 }
3096 return 0;
3097 }
3098
3099 static int find_iref(struct send_ctx *sctx,
3100 struct btrfs_root *root,
3101 struct btrfs_path *path,
3102 struct btrfs_key *key,
3103 u64 dir, struct fs_path *name)
3104 {
3105 int ret;
3106 struct find_ref_ctx ctx;
3107
3108 ctx.dir = dir;
3109 ctx.name = name;
3110 ctx.found_idx = -1;
3111
3112 ret = iterate_inode_ref(sctx, root, path, key, 0, __find_iref, &ctx);
3113 if (ret < 0)
3114 return ret;
3115
3116 if (ctx.found_idx == -1)
3117 return -ENOENT;
3118
3119 return ctx.found_idx;
3120 }
3121
3122 static int __record_changed_new_ref(int num, u64 dir, int index,
3123 struct fs_path *name,
3124 void *ctx)
3125 {
3126 int ret;
3127 struct send_ctx *sctx = ctx;
3128
3129 ret = find_iref(sctx, sctx->parent_root, sctx->right_path,
3130 sctx->cmp_key, dir, name);
3131 if (ret == -ENOENT)
3132 ret = __record_new_ref(num, dir, index, name, sctx);
3133 else if (ret > 0)
3134 ret = 0;
3135
3136 return ret;
3137 }
3138
3139 static int __record_changed_deleted_ref(int num, u64 dir, int index,
3140 struct fs_path *name,
3141 void *ctx)
3142 {
3143 int ret;
3144 struct send_ctx *sctx = ctx;
3145
3146 ret = find_iref(sctx, sctx->send_root, sctx->left_path, sctx->cmp_key,
3147 dir, name);
3148 if (ret == -ENOENT)
3149 ret = __record_deleted_ref(num, dir, index, name, sctx);
3150 else if (ret > 0)
3151 ret = 0;
3152
3153 return ret;
3154 }
3155
3156 static int record_changed_ref(struct send_ctx *sctx)
3157 {
3158 int ret = 0;
3159
3160 ret = iterate_inode_ref(sctx, sctx->send_root, sctx->left_path,
3161 sctx->cmp_key, 0, __record_changed_new_ref, sctx);
3162 if (ret < 0)
3163 goto out;
3164 ret = iterate_inode_ref(sctx, sctx->parent_root, sctx->right_path,
3165 sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
3166 if (ret < 0)
3167 goto out;
3168 ret = 0;
3169
3170 out:
3171 return ret;
3172 }
3173
3174 /*
3175 * Record and process all refs at once. Needed when an inode changes the
3176 * generation number, which means that it was deleted and recreated.
3177 */
3178 static int process_all_refs(struct send_ctx *sctx,
3179 enum btrfs_compare_tree_result cmd)
3180 {
3181 int ret;
3182 struct btrfs_root *root;
3183 struct btrfs_path *path;
3184 struct btrfs_key key;
3185 struct btrfs_key found_key;
3186 struct extent_buffer *eb;
3187 int slot;
3188 iterate_inode_ref_t cb;
3189
3190 path = alloc_path_for_send();
3191 if (!path)
3192 return -ENOMEM;
3193
3194 if (cmd == BTRFS_COMPARE_TREE_NEW) {
3195 root = sctx->send_root;
3196 cb = __record_new_ref;
3197 } else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
3198 root = sctx->parent_root;
3199 cb = __record_deleted_ref;
3200 } else {
3201 BUG();
3202 }
3203
3204 key.objectid = sctx->cmp_key->objectid;
3205 key.type = BTRFS_INODE_REF_KEY;
3206 key.offset = 0;
3207 while (1) {
3208 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3209 if (ret < 0) {
3210 btrfs_release_path(path);
3211 goto out;
3212 }
3213 if (ret) {
3214 btrfs_release_path(path);
3215 break;
3216 }
3217
3218 eb = path->nodes[0];
3219 slot = path->slots[0];
3220 btrfs_item_key_to_cpu(eb, &found_key, slot);
3221
3222 if (found_key.objectid != key.objectid ||
3223 found_key.type != key.type) {
3224 btrfs_release_path(path);
3225 break;
3226 }
3227
3228 ret = iterate_inode_ref(sctx, sctx->parent_root, path,
3229 &found_key, 0, cb, sctx);
3230 btrfs_release_path(path);
3231 if (ret < 0)
3232 goto out;
3233
3234 key.offset = found_key.offset + 1;
3235 }
3236
3237 ret = process_recorded_refs(sctx);
3238
3239 out:
3240 btrfs_free_path(path);
3241 return ret;
3242 }
3243
3244 static int send_set_xattr(struct send_ctx *sctx,
3245 struct fs_path *path,
3246 const char *name, int name_len,
3247 const char *data, int data_len)
3248 {
3249 int ret = 0;
3250
3251 ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
3252 if (ret < 0)
3253 goto out;
3254
3255 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3256 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3257 TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
3258
3259 ret = send_cmd(sctx);
3260
3261 tlv_put_failure:
3262 out:
3263 return ret;
3264 }
3265
3266 static int send_remove_xattr(struct send_ctx *sctx,
3267 struct fs_path *path,
3268 const char *name, int name_len)
3269 {
3270 int ret = 0;
3271
3272 ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
3273 if (ret < 0)
3274 goto out;
3275
3276 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3277 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3278
3279 ret = send_cmd(sctx);
3280
3281 tlv_put_failure:
3282 out:
3283 return ret;
3284 }
3285
3286 static int __process_new_xattr(int num, struct btrfs_key *di_key,
3287 const char *name, int name_len,
3288 const char *data, int data_len,
3289 u8 type, void *ctx)
3290 {
3291 int ret;
3292 struct send_ctx *sctx = ctx;
3293 struct fs_path *p;
3294 posix_acl_xattr_header dummy_acl;
3295
3296 p = fs_path_alloc(sctx);
3297 if (!p)
3298 return -ENOMEM;
3299
3300 /*
3301 * This hack is needed because empty acl's are stored as zero byte
3302 * data in xattrs. Problem with that is, that receiving these zero byte
3303 * acl's will fail later. To fix this, we send a dummy acl list that
3304 * only contains the version number and no entries.
3305 */
3306 if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
3307 !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
3308 if (data_len == 0) {
3309 dummy_acl.a_version =
3310 cpu_to_le32(POSIX_ACL_XATTR_VERSION);
3311 data = (char *)&dummy_acl;
3312 data_len = sizeof(dummy_acl);
3313 }
3314 }
3315
3316 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3317 if (ret < 0)
3318 goto out;
3319
3320 ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
3321
3322 out:
3323 fs_path_free(sctx, p);
3324 return ret;
3325 }
3326
3327 static int __process_deleted_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
3336 p = fs_path_alloc(sctx);
3337 if (!p)
3338 return -ENOMEM;
3339
3340 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3341 if (ret < 0)
3342 goto out;
3343
3344 ret = send_remove_xattr(sctx, p, name, name_len);
3345
3346 out:
3347 fs_path_free(sctx, p);
3348 return ret;
3349 }
3350
3351 static int process_new_xattr(struct send_ctx *sctx)
3352 {
3353 int ret = 0;
3354
3355 ret = iterate_dir_item(sctx, sctx->send_root, sctx->left_path,
3356 sctx->cmp_key, __process_new_xattr, sctx);
3357
3358 return ret;
3359 }
3360
3361 static int process_deleted_xattr(struct send_ctx *sctx)
3362 {
3363 int ret;
3364
3365 ret = iterate_dir_item(sctx, sctx->parent_root, sctx->right_path,
3366 sctx->cmp_key, __process_deleted_xattr, sctx);
3367
3368 return ret;
3369 }
3370
3371 struct find_xattr_ctx {
3372 const char *name;
3373 int name_len;
3374 int found_idx;
3375 char *found_data;
3376 int found_data_len;
3377 };
3378
3379 static int __find_xattr(int num, struct btrfs_key *di_key,
3380 const char *name, int name_len,
3381 const char *data, int data_len,
3382 u8 type, void *vctx)
3383 {
3384 struct find_xattr_ctx *ctx = vctx;
3385
3386 if (name_len == ctx->name_len &&
3387 strncmp(name, ctx->name, name_len) == 0) {
3388 ctx->found_idx = num;
3389 ctx->found_data_len = data_len;
3390 ctx->found_data = kmalloc(data_len, GFP_NOFS);
3391 if (!ctx->found_data)
3392 return -ENOMEM;
3393 memcpy(ctx->found_data, data, data_len);
3394 return 1;
3395 }
3396 return 0;
3397 }
3398
3399 static int find_xattr(struct send_ctx *sctx,
3400 struct btrfs_root *root,
3401 struct btrfs_path *path,
3402 struct btrfs_key *key,
3403 const char *name, int name_len,
3404 char **data, int *data_len)
3405 {
3406 int ret;
3407 struct find_xattr_ctx ctx;
3408
3409 ctx.name = name;
3410 ctx.name_len = name_len;
3411 ctx.found_idx = -1;
3412 ctx.found_data = NULL;
3413 ctx.found_data_len = 0;
3414
3415 ret = iterate_dir_item(sctx, root, path, key, __find_xattr, &ctx);
3416 if (ret < 0)
3417 return ret;
3418
3419 if (ctx.found_idx == -1)
3420 return -ENOENT;
3421 if (data) {
3422 *data = ctx.found_data;
3423 *data_len = ctx.found_data_len;
3424 } else {
3425 kfree(ctx.found_data);
3426 }
3427 return ctx.found_idx;
3428 }
3429
3430
3431 static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
3432 const char *name, int name_len,
3433 const char *data, int data_len,
3434 u8 type, void *ctx)
3435 {
3436 int ret;
3437 struct send_ctx *sctx = ctx;
3438 char *found_data = NULL;
3439 int found_data_len = 0;
3440 struct fs_path *p = NULL;
3441
3442 ret = find_xattr(sctx, sctx->parent_root, sctx->right_path,
3443 sctx->cmp_key, name, name_len, &found_data,
3444 &found_data_len);
3445 if (ret == -ENOENT) {
3446 ret = __process_new_xattr(num, di_key, name, name_len, data,
3447 data_len, type, ctx);
3448 } else if (ret >= 0) {
3449 if (data_len != found_data_len ||
3450 memcmp(data, found_data, data_len)) {
3451 ret = __process_new_xattr(num, di_key, name, name_len,
3452 data, data_len, type, ctx);
3453 } else {
3454 ret = 0;
3455 }
3456 }
3457
3458 kfree(found_data);
3459 fs_path_free(sctx, p);
3460 return ret;
3461 }
3462
3463 static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
3464 const char *name, int name_len,
3465 const char *data, int data_len,
3466 u8 type, void *ctx)
3467 {
3468 int ret;
3469 struct send_ctx *sctx = ctx;
3470
3471 ret = find_xattr(sctx, sctx->send_root, sctx->left_path, sctx->cmp_key,
3472 name, name_len, NULL, NULL);
3473 if (ret == -ENOENT)
3474 ret = __process_deleted_xattr(num, di_key, name, name_len, data,
3475 data_len, type, ctx);
3476 else if (ret >= 0)
3477 ret = 0;
3478
3479 return ret;
3480 }
3481
3482 static int process_changed_xattr(struct send_ctx *sctx)
3483 {
3484 int ret = 0;
3485
3486 ret = iterate_dir_item(sctx, sctx->send_root, sctx->left_path,
3487 sctx->cmp_key, __process_changed_new_xattr, sctx);
3488 if (ret < 0)
3489 goto out;
3490 ret = iterate_dir_item(sctx, sctx->parent_root, sctx->right_path,
3491 sctx->cmp_key, __process_changed_deleted_xattr, sctx);
3492
3493 out:
3494 return ret;
3495 }
3496
3497 static int process_all_new_xattrs(struct send_ctx *sctx)
3498 {
3499 int ret;
3500 struct btrfs_root *root;
3501 struct btrfs_path *path;
3502 struct btrfs_key key;
3503 struct btrfs_key found_key;
3504 struct extent_buffer *eb;
3505 int slot;
3506
3507 path = alloc_path_for_send();
3508 if (!path)
3509 return -ENOMEM;
3510
3511 root = sctx->send_root;
3512
3513 key.objectid = sctx->cmp_key->objectid;
3514 key.type = BTRFS_XATTR_ITEM_KEY;
3515 key.offset = 0;
3516 while (1) {
3517 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3518 if (ret < 0)
3519 goto out;
3520 if (ret) {
3521 ret = 0;
3522 goto out;
3523 }
3524
3525 eb = path->nodes[0];
3526 slot = path->slots[0];
3527 btrfs_item_key_to_cpu(eb, &found_key, slot);
3528
3529 if (found_key.objectid != key.objectid ||
3530 found_key.type != key.type) {
3531 ret = 0;
3532 goto out;
3533 }
3534
3535 ret = iterate_dir_item(sctx, root, path, &found_key,
3536 __process_new_xattr, sctx);
3537 if (ret < 0)
3538 goto out;
3539
3540 btrfs_release_path(path);
3541 key.offset = found_key.offset + 1;
3542 }
3543
3544 out:
3545 btrfs_free_path(path);
3546 return ret;
3547 }
3548
3549 /*
3550 * Read some bytes from the current inode/file and send a write command to
3551 * user space.
3552 */
3553 static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
3554 {
3555 int ret = 0;
3556 struct fs_path *p;
3557 loff_t pos = offset;
3558 int readed = 0;
3559 mm_segment_t old_fs;
3560
3561 p = fs_path_alloc(sctx);
3562 if (!p)
3563 return -ENOMEM;
3564
3565 /*
3566 * vfs normally only accepts user space buffers for security reasons.
3567 * we only read from the file and also only provide the read_buf buffer
3568 * to vfs. As this buffer does not come from a user space call, it's
3569 * ok to temporary allow kernel space buffers.
3570 */
3571 old_fs = get_fs();
3572 set_fs(KERNEL_DS);
3573
3574 verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len);
3575
3576 ret = open_cur_inode_file(sctx);
3577 if (ret < 0)
3578 goto out;
3579
3580 ret = vfs_read(sctx->cur_inode_filp, sctx->read_buf, len, &pos);
3581 if (ret < 0)
3582 goto out;
3583 readed = ret;
3584 if (!readed)
3585 goto out;
3586
3587 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
3588 if (ret < 0)
3589 goto out;
3590
3591 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3592 if (ret < 0)
3593 goto out;
3594
3595 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
3596 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
3597 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, readed);
3598
3599 ret = send_cmd(sctx);
3600
3601 tlv_put_failure:
3602 out:
3603 fs_path_free(sctx, p);
3604 set_fs(old_fs);
3605 if (ret < 0)
3606 return ret;
3607 return readed;
3608 }
3609
3610 /*
3611 * Send a clone command to user space.
3612 */
3613 static int send_clone(struct send_ctx *sctx,
3614 u64 offset, u32 len,
3615 struct clone_root *clone_root)
3616 {
3617 int ret = 0;
3618 struct btrfs_root *clone_root2 = clone_root->root;
3619 struct fs_path *p;
3620 u64 gen;
3621
3622 verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, "
3623 "clone_inode=%llu, clone_offset=%llu\n", offset, len,
3624 clone_root->root->objectid, clone_root->ino,
3625 clone_root->offset);
3626
3627 p = fs_path_alloc(sctx);
3628 if (!p)
3629 return -ENOMEM;
3630
3631 ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
3632 if (ret < 0)
3633 goto out;
3634
3635 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3636 if (ret < 0)
3637 goto out;
3638
3639 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
3640 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
3641 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
3642
3643 if (clone_root2 == sctx->send_root) {
3644 ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
3645 &gen, NULL, NULL, NULL);
3646 if (ret < 0)
3647 goto out;
3648 ret = get_cur_path(sctx, clone_root->ino, gen, p);
3649 } else {
3650 ret = get_inode_path(sctx, clone_root2, clone_root->ino, p);
3651 }
3652 if (ret < 0)
3653 goto out;
3654
3655 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
3656 clone_root2->root_item.uuid);
3657 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
3658 clone_root2->root_item.ctransid);
3659 TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
3660 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
3661 clone_root->offset);
3662
3663 ret = send_cmd(sctx);
3664
3665 tlv_put_failure:
3666 out:
3667 fs_path_free(sctx, p);
3668 return ret;
3669 }
3670
3671 static int send_write_or_clone(struct send_ctx *sctx,
3672 struct btrfs_path *path,
3673 struct btrfs_key *key,
3674 struct clone_root *clone_root)
3675 {
3676 int ret = 0;
3677 struct btrfs_file_extent_item *ei;
3678 u64 offset = key->offset;
3679 u64 pos = 0;
3680 u64 len;
3681 u32 l;
3682 u8 type;
3683
3684 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3685 struct btrfs_file_extent_item);
3686 type = btrfs_file_extent_type(path->nodes[0], ei);
3687 if (type == BTRFS_FILE_EXTENT_INLINE)
3688 len = btrfs_file_extent_inline_len(path->nodes[0], ei);
3689 else
3690 len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3691
3692 if (offset + len > sctx->cur_inode_size)
3693 len = sctx->cur_inode_size - offset;
3694 if (len == 0) {
3695 ret = 0;
3696 goto out;
3697 }
3698
3699 if (!clone_root) {
3700 while (pos < len) {
3701 l = len - pos;
3702 if (l > BTRFS_SEND_READ_SIZE)
3703 l = BTRFS_SEND_READ_SIZE;
3704 ret = send_write(sctx, pos + offset, l);
3705 if (ret < 0)
3706 goto out;
3707 if (!ret)
3708 break;
3709 pos += ret;
3710 }
3711 ret = 0;
3712 } else {
3713 ret = send_clone(sctx, offset, len, clone_root);
3714 }
3715
3716 out:
3717 return ret;
3718 }
3719
3720 static int is_extent_unchanged(struct send_ctx *sctx,
3721 struct btrfs_path *left_path,
3722 struct btrfs_key *ekey)
3723 {
3724 int ret = 0;
3725 struct btrfs_key key;
3726 struct btrfs_path *path = NULL;
3727 struct extent_buffer *eb;
3728 int slot;
3729 struct btrfs_key found_key;
3730 struct btrfs_file_extent_item *ei;
3731 u64 left_disknr;
3732 u64 right_disknr;
3733 u64 left_offset;
3734 u64 right_offset;
3735 u64 left_offset_fixed;
3736 u64 left_len;
3737 u64 right_len;
3738 u8 left_type;
3739 u8 right_type;
3740
3741 path = alloc_path_for_send();
3742 if (!path)
3743 return -ENOMEM;
3744
3745 eb = left_path->nodes[0];
3746 slot = left_path->slots[0];
3747
3748 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
3749 left_type = btrfs_file_extent_type(eb, ei);
3750 left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
3751 left_len = btrfs_file_extent_num_bytes(eb, ei);
3752 left_offset = btrfs_file_extent_offset(eb, ei);
3753
3754 if (left_type != BTRFS_FILE_EXTENT_REG) {
3755 ret = 0;
3756 goto out;
3757 }
3758
3759 /*
3760 * Following comments will refer to these graphics. L is the left
3761 * extents which we are checking at the moment. 1-8 are the right
3762 * extents that we iterate.
3763 *
3764 * |-----L-----|
3765 * |-1-|-2a-|-3-|-4-|-5-|-6-|
3766 *
3767 * |-----L-----|
3768 * |--1--|-2b-|...(same as above)
3769 *
3770 * Alternative situation. Happens on files where extents got split.
3771 * |-----L-----|
3772 * |-----------7-----------|-6-|
3773 *
3774 * Alternative situation. Happens on files which got larger.
3775 * |-----L-----|
3776 * |-8-|
3777 * Nothing follows after 8.
3778 */
3779
3780 key.objectid = ekey->objectid;
3781 key.type = BTRFS_EXTENT_DATA_KEY;
3782 key.offset = ekey->offset;
3783 ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
3784 if (ret < 0)
3785 goto out;
3786 if (ret) {
3787 ret = 0;
3788 goto out;
3789 }
3790
3791 /*
3792 * Handle special case where the right side has no extents at all.
3793 */
3794 eb = path->nodes[0];
3795 slot = path->slots[0];
3796 btrfs_item_key_to_cpu(eb, &found_key, slot);
3797 if (found_key.objectid != key.objectid ||
3798 found_key.type != key.type) {
3799 ret = 0;
3800 goto out;
3801 }
3802
3803 /*
3804 * We're now on 2a, 2b or 7.
3805 */
3806 key = found_key;
3807 while (key.offset < ekey->offset + left_len) {
3808 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
3809 right_type = btrfs_file_extent_type(eb, ei);
3810 right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
3811 right_len = btrfs_file_extent_num_bytes(eb, ei);
3812 right_offset = btrfs_file_extent_offset(eb, ei);
3813
3814 if (right_type != BTRFS_FILE_EXTENT_REG) {
3815 ret = 0;
3816 goto out;
3817 }
3818
3819 /*
3820 * Are we at extent 8? If yes, we know the extent is changed.
3821 * This may only happen on the first iteration.
3822 */
3823 if (found_key.offset + right_len < ekey->offset) {
3824 ret = 0;
3825 goto out;
3826 }
3827
3828 left_offset_fixed = left_offset;
3829 if (key.offset < ekey->offset) {
3830 /* Fix the right offset for 2a and 7. */
3831 right_offset += ekey->offset - key.offset;
3832 } else {
3833 /* Fix the left offset for all behind 2a and 2b */
3834 left_offset_fixed += key.offset - ekey->offset;
3835 }
3836
3837 /*
3838 * Check if we have the same extent.
3839 */
3840 if (left_disknr + left_offset_fixed !=
3841 right_disknr + right_offset) {
3842 ret = 0;
3843 goto out;
3844 }
3845
3846 /*
3847 * Go to the next extent.
3848 */
3849 ret = btrfs_next_item(sctx->parent_root, path);
3850 if (ret < 0)
3851 goto out;
3852 if (!ret) {
3853 eb = path->nodes[0];
3854 slot = path->slots[0];
3855 btrfs_item_key_to_cpu(eb, &found_key, slot);
3856 }
3857 if (ret || found_key.objectid != key.objectid ||
3858 found_key.type != key.type) {
3859 key.offset += right_len;
3860 break;
3861 } else {
3862 if (found_key.offset != key.offset + right_len) {
3863 /* Should really not happen */
3864 ret = -EIO;
3865 goto out;
3866 }
3867 }
3868 key = found_key;
3869 }
3870
3871 /*
3872 * We're now behind the left extent (treat as unchanged) or at the end
3873 * of the right side (treat as changed).
3874 */
3875 if (key.offset >= ekey->offset + left_len)
3876 ret = 1;
3877 else
3878 ret = 0;
3879
3880
3881 out:
3882 btrfs_free_path(path);
3883 return ret;
3884 }
3885
3886 static int process_extent(struct send_ctx *sctx,
3887 struct btrfs_path *path,
3888 struct btrfs_key *key)
3889 {
3890 int ret = 0;
3891 struct clone_root *found_clone = NULL;
3892
3893 if (S_ISLNK(sctx->cur_inode_mode))
3894 return 0;
3895
3896 if (sctx->parent_root && !sctx->cur_inode_new) {
3897 ret = is_extent_unchanged(sctx, path, key);
3898 if (ret < 0)
3899 goto out;
3900 if (ret) {
3901 ret = 0;
3902 goto out;
3903 }
3904 }
3905
3906 ret = find_extent_clone(sctx, path, key->objectid, key->offset,
3907 sctx->cur_inode_size, &found_clone);
3908 if (ret != -ENOENT && ret < 0)
3909 goto out;
3910
3911 ret = send_write_or_clone(sctx, path, key, found_clone);
3912
3913 out:
3914 return ret;
3915 }
3916
3917 static int process_all_extents(struct send_ctx *sctx)
3918 {
3919 int ret;
3920 struct btrfs_root *root;
3921 struct btrfs_path *path;
3922 struct btrfs_key key;
3923 struct btrfs_key found_key;
3924 struct extent_buffer *eb;
3925 int slot;
3926
3927 root = sctx->send_root;
3928 path = alloc_path_for_send();
3929 if (!path)
3930 return -ENOMEM;
3931
3932 key.objectid = sctx->cmp_key->objectid;
3933 key.type = BTRFS_EXTENT_DATA_KEY;
3934 key.offset = 0;
3935 while (1) {
3936 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3937 if (ret < 0)
3938 goto out;
3939 if (ret) {
3940 ret = 0;
3941 goto out;
3942 }
3943
3944 eb = path->nodes[0];
3945 slot = path->slots[0];
3946 btrfs_item_key_to_cpu(eb, &found_key, slot);
3947
3948 if (found_key.objectid != key.objectid ||
3949 found_key.type != key.type) {
3950 ret = 0;
3951 goto out;
3952 }
3953
3954 ret = process_extent(sctx, path, &found_key);
3955 if (ret < 0)
3956 goto out;
3957
3958 btrfs_release_path(path);
3959 key.offset = found_key.offset + 1;
3960 }
3961
3962 out:
3963 btrfs_free_path(path);
3964 return ret;
3965 }
3966
3967 static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end)
3968 {
3969 int ret = 0;
3970
3971 if (sctx->cur_ino == 0)
3972 goto out;
3973 if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
3974 sctx->cmp_key->type <= BTRFS_INODE_REF_KEY)
3975 goto out;
3976 if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
3977 goto out;
3978
3979 ret = process_recorded_refs(sctx);
3980
3981 out:
3982 return ret;
3983 }
3984
3985 static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
3986 {
3987 int ret = 0;
3988 u64 left_mode;
3989 u64 left_uid;
3990 u64 left_gid;
3991 u64 right_mode;
3992 u64 right_uid;
3993 u64 right_gid;
3994 int need_chmod = 0;
3995 int need_chown = 0;
3996
3997 ret = process_recorded_refs_if_needed(sctx, at_end);
3998 if (ret < 0)
3999 goto out;
4000
4001 if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
4002 goto out;
4003 if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
4004 goto out;
4005
4006 ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
4007 &left_mode, &left_uid, &left_gid);
4008 if (ret < 0)
4009 goto out;
4010
4011 if (!S_ISLNK(sctx->cur_inode_mode)) {
4012 if (!sctx->parent_root || sctx->cur_inode_new) {
4013 need_chmod = 1;
4014 need_chown = 1;
4015 } else {
4016 ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
4017 NULL, NULL, &right_mode, &right_uid,
4018 &right_gid);
4019 if (ret < 0)
4020 goto out;
4021
4022 if (left_uid != right_uid || left_gid != right_gid)
4023 need_chown = 1;
4024 if (left_mode != right_mode)
4025 need_chmod = 1;
4026 }
4027 }
4028
4029 if (S_ISREG(sctx->cur_inode_mode)) {
4030 ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4031 sctx->cur_inode_size);
4032 if (ret < 0)
4033 goto out;
4034 }
4035
4036 if (need_chown) {
4037 ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4038 left_uid, left_gid);
4039 if (ret < 0)
4040 goto out;
4041 }
4042 if (need_chmod) {
4043 ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4044 left_mode);
4045 if (ret < 0)
4046 goto out;
4047 }
4048
4049 /*
4050 * Need to send that every time, no matter if it actually changed
4051 * between the two trees as we have done changes to the inode before.
4052 */
4053 ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
4054 if (ret < 0)
4055 goto out;
4056
4057 out:
4058 return ret;
4059 }
4060
4061 static int changed_inode(struct send_ctx *sctx,
4062 enum btrfs_compare_tree_result result)
4063 {
4064 int ret = 0;
4065 struct btrfs_key *key = sctx->cmp_key;
4066 struct btrfs_inode_item *left_ii = NULL;
4067 struct btrfs_inode_item *right_ii = NULL;
4068 u64 left_gen = 0;
4069 u64 right_gen = 0;
4070
4071 ret = close_cur_inode_file(sctx);
4072 if (ret < 0)
4073 goto out;
4074
4075 sctx->cur_ino = key->objectid;
4076 sctx->cur_inode_new_gen = 0;
4077 sctx->cur_inode_first_ref_orphan = 0;
4078 sctx->send_progress = sctx->cur_ino;
4079
4080 if (result == BTRFS_COMPARE_TREE_NEW ||
4081 result == BTRFS_COMPARE_TREE_CHANGED) {
4082 left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
4083 sctx->left_path->slots[0],
4084 struct btrfs_inode_item);
4085 left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
4086 left_ii);
4087 } else {
4088 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
4089 sctx->right_path->slots[0],
4090 struct btrfs_inode_item);
4091 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
4092 right_ii);
4093 }
4094 if (result == BTRFS_COMPARE_TREE_CHANGED) {
4095 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
4096 sctx->right_path->slots[0],
4097 struct btrfs_inode_item);
4098
4099 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
4100 right_ii);
4101 if (left_gen != right_gen)
4102 sctx->cur_inode_new_gen = 1;
4103 }
4104
4105 if (result == BTRFS_COMPARE_TREE_NEW) {
4106 sctx->cur_inode_gen = left_gen;
4107 sctx->cur_inode_new = 1;
4108 sctx->cur_inode_deleted = 0;
4109 sctx->cur_inode_size = btrfs_inode_size(
4110 sctx->left_path->nodes[0], left_ii);
4111 sctx->cur_inode_mode = btrfs_inode_mode(
4112 sctx->left_path->nodes[0], left_ii);
4113 if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
4114 ret = send_create_inode(sctx, sctx->left_path,
4115 sctx->cmp_key);
4116 } else if (result == BTRFS_COMPARE_TREE_DELETED) {
4117 sctx->cur_inode_gen = right_gen;
4118 sctx->cur_inode_new = 0;
4119 sctx->cur_inode_deleted = 1;
4120 sctx->cur_inode_size = btrfs_inode_size(
4121 sctx->right_path->nodes[0], right_ii);
4122 sctx->cur_inode_mode = btrfs_inode_mode(
4123 sctx->right_path->nodes[0], right_ii);
4124 } else if (result == BTRFS_COMPARE_TREE_CHANGED) {
4125 if (sctx->cur_inode_new_gen) {
4126 sctx->cur_inode_gen = right_gen;
4127 sctx->cur_inode_new = 0;
4128 sctx->cur_inode_deleted = 1;
4129 sctx->cur_inode_size = btrfs_inode_size(
4130 sctx->right_path->nodes[0], right_ii);
4131 sctx->cur_inode_mode = btrfs_inode_mode(
4132 sctx->right_path->nodes[0], right_ii);
4133 ret = process_all_refs(sctx,
4134 BTRFS_COMPARE_TREE_DELETED);
4135 if (ret < 0)
4136 goto out;
4137
4138 sctx->cur_inode_gen = left_gen;
4139 sctx->cur_inode_new = 1;
4140 sctx->cur_inode_deleted = 0;
4141 sctx->cur_inode_size = btrfs_inode_size(
4142 sctx->left_path->nodes[0], left_ii);
4143 sctx->cur_inode_mode = btrfs_inode_mode(
4144 sctx->left_path->nodes[0], left_ii);
4145 ret = send_create_inode(sctx, sctx->left_path,
4146 sctx->cmp_key);
4147 if (ret < 0)
4148 goto out;
4149
4150 ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
4151 if (ret < 0)
4152 goto out;
4153 ret = process_all_extents(sctx);
4154 if (ret < 0)
4155 goto out;
4156 ret = process_all_new_xattrs(sctx);
4157 if (ret < 0)
4158 goto out;
4159 } else {
4160 sctx->cur_inode_gen = left_gen;
4161 sctx->cur_inode_new = 0;
4162 sctx->cur_inode_new_gen = 0;
4163 sctx->cur_inode_deleted = 0;
4164 sctx->cur_inode_size = btrfs_inode_size(
4165 sctx->left_path->nodes[0], left_ii);
4166 sctx->cur_inode_mode = btrfs_inode_mode(
4167 sctx->left_path->nodes[0], left_ii);
4168 }
4169 }
4170
4171 out:
4172 return ret;
4173 }
4174
4175 static int changed_ref(struct send_ctx *sctx,
4176 enum btrfs_compare_tree_result result)
4177 {
4178 int ret = 0;
4179
4180 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4181
4182 if (!sctx->cur_inode_new_gen &&
4183 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
4184 if (result == BTRFS_COMPARE_TREE_NEW)
4185 ret = record_new_ref(sctx);
4186 else if (result == BTRFS_COMPARE_TREE_DELETED)
4187 ret = record_deleted_ref(sctx);
4188 else if (result == BTRFS_COMPARE_TREE_CHANGED)
4189 ret = record_changed_ref(sctx);
4190 }
4191
4192 return ret;
4193 }
4194
4195 static int changed_xattr(struct send_ctx *sctx,
4196 enum btrfs_compare_tree_result result)
4197 {
4198 int ret = 0;
4199
4200 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4201
4202 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
4203 if (result == BTRFS_COMPARE_TREE_NEW)
4204 ret = process_new_xattr(sctx);
4205 else if (result == BTRFS_COMPARE_TREE_DELETED)
4206 ret = process_deleted_xattr(sctx);
4207 else if (result == BTRFS_COMPARE_TREE_CHANGED)
4208 ret = process_changed_xattr(sctx);
4209 }
4210
4211 return ret;
4212 }
4213
4214 static int changed_extent(struct send_ctx *sctx,
4215 enum btrfs_compare_tree_result result)
4216 {
4217 int ret = 0;
4218
4219 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4220
4221 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
4222 if (result != BTRFS_COMPARE_TREE_DELETED)
4223 ret = process_extent(sctx, sctx->left_path,
4224 sctx->cmp_key);
4225 }
4226
4227 return ret;
4228 }
4229
4230
4231 static int changed_cb(struct btrfs_root *left_root,
4232 struct btrfs_root *right_root,
4233 struct btrfs_path *left_path,
4234 struct btrfs_path *right_path,
4235 struct btrfs_key *key,
4236 enum btrfs_compare_tree_result result,
4237 void *ctx)
4238 {
4239 int ret = 0;
4240 struct send_ctx *sctx = ctx;
4241
4242 sctx->left_path = left_path;
4243 sctx->right_path = right_path;
4244 sctx->cmp_key = key;
4245
4246 ret = finish_inode_if_needed(sctx, 0);
4247 if (ret < 0)
4248 goto out;
4249
4250 if (key->type == BTRFS_INODE_ITEM_KEY)
4251 ret = changed_inode(sctx, result);
4252 else if (key->type == BTRFS_INODE_REF_KEY)
4253 ret = changed_ref(sctx, result);
4254 else if (key->type == BTRFS_XATTR_ITEM_KEY)
4255 ret = changed_xattr(sctx, result);
4256 else if (key->type == BTRFS_EXTENT_DATA_KEY)
4257 ret = changed_extent(sctx, result);
4258
4259 out:
4260 return ret;
4261 }
4262
4263 static int full_send_tree(struct send_ctx *sctx)
4264 {
4265 int ret;
4266 struct btrfs_trans_handle *trans = NULL;
4267 struct btrfs_root *send_root = sctx->send_root;
4268 struct btrfs_key key;
4269 struct btrfs_key found_key;
4270 struct btrfs_path *path;
4271 struct extent_buffer *eb;
4272 int slot;
4273 u64 start_ctransid;
4274 u64 ctransid;
4275
4276 path = alloc_path_for_send();
4277 if (!path)
4278 return -ENOMEM;
4279
4280 spin_lock(&send_root->root_times_lock);
4281 start_ctransid = btrfs_root_ctransid(&send_root->root_item);
4282 spin_unlock(&send_root->root_times_lock);
4283
4284 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
4285 key.type = BTRFS_INODE_ITEM_KEY;
4286 key.offset = 0;
4287
4288 join_trans:
4289 /*
4290 * We need to make sure the transaction does not get committed
4291 * while we do anything on commit roots. Join a transaction to prevent
4292 * this.
4293 */
4294 trans = btrfs_join_transaction(send_root);
4295 if (IS_ERR(trans)) {
4296 ret = PTR_ERR(trans);
4297 trans = NULL;
4298 goto out;
4299 }
4300
4301 /*
4302 * Make sure the tree has not changed
4303 */
4304 spin_lock(&send_root->root_times_lock);
4305 ctransid = btrfs_root_ctransid(&send_root->root_item);
4306 spin_unlock(&send_root->root_times_lock);
4307
4308 if (ctransid != start_ctransid) {
4309 WARN(1, KERN_WARNING "btrfs: the root that you're trying to "
4310 "send was modified in between. This is "
4311 "probably a bug.\n");
4312 ret = -EIO;
4313 goto out;
4314 }
4315
4316 ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
4317 if (ret < 0)
4318 goto out;
4319 if (ret)
4320 goto out_finish;
4321
4322 while (1) {
4323 /*
4324 * When someone want to commit while we iterate, end the
4325 * joined transaction and rejoin.
4326 */
4327 if (btrfs_should_end_transaction(trans, send_root)) {
4328 ret = btrfs_end_transaction(trans, send_root);
4329 trans = NULL;
4330 if (ret < 0)
4331 goto out;
4332 btrfs_release_path(path);
4333 goto join_trans;
4334 }
4335
4336 eb = path->nodes[0];
4337 slot = path->slots[0];
4338 btrfs_item_key_to_cpu(eb, &found_key, slot);
4339
4340 ret = changed_cb(send_root, NULL, path, NULL,
4341 &found_key, BTRFS_COMPARE_TREE_NEW, sctx);
4342 if (ret < 0)
4343 goto out;
4344
4345 key.objectid = found_key.objectid;
4346 key.type = found_key.type;
4347 key.offset = found_key.offset + 1;
4348
4349 ret = btrfs_next_item(send_root, path);
4350 if (ret < 0)
4351 goto out;
4352 if (ret) {
4353 ret = 0;
4354 break;
4355 }
4356 }
4357
4358 out_finish:
4359 ret = finish_inode_if_needed(sctx, 1);
4360
4361 out:
4362 btrfs_free_path(path);
4363 if (trans) {
4364 if (!ret)
4365 ret = btrfs_end_transaction(trans, send_root);
4366 else
4367 btrfs_end_transaction(trans, send_root);
4368 }
4369 return ret;
4370 }
4371
4372 static int send_subvol(struct send_ctx *sctx)
4373 {
4374 int ret;
4375
4376 ret = send_header(sctx);
4377 if (ret < 0)
4378 goto out;
4379
4380 ret = send_subvol_begin(sctx);
4381 if (ret < 0)
4382 goto out;
4383
4384 if (sctx->parent_root) {
4385 ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
4386 changed_cb, sctx);
4387 if (ret < 0)
4388 goto out;
4389 ret = finish_inode_if_needed(sctx, 1);
4390 if (ret < 0)
4391 goto out;
4392 } else {
4393 ret = full_send_tree(sctx);
4394 if (ret < 0)
4395 goto out;
4396 }
4397
4398 out:
4399 if (!ret)
4400 ret = close_cur_inode_file(sctx);
4401 else
4402 close_cur_inode_file(sctx);
4403
4404 free_recorded_refs(sctx);
4405 return ret;
4406 }
4407
4408 long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
4409 {
4410 int ret = 0;
4411 struct btrfs_root *send_root;
4412 struct btrfs_root *clone_root;
4413 struct btrfs_fs_info *fs_info;
4414 struct btrfs_ioctl_send_args *arg = NULL;
4415 struct btrfs_key key;
4416 struct file *filp = NULL;
4417 struct send_ctx *sctx = NULL;
4418 u32 i;
4419 u64 *clone_sources_tmp = NULL;
4420
4421 if (!capable(CAP_SYS_ADMIN))
4422 return -EPERM;
4423
4424 send_root = BTRFS_I(fdentry(mnt_file)->d_inode)->root;
4425 fs_info = send_root->fs_info;
4426
4427 arg = memdup_user(arg_, sizeof(*arg));
4428 if (IS_ERR(arg)) {
4429 ret = PTR_ERR(arg);
4430 arg = NULL;
4431 goto out;
4432 }
4433
4434 if (!access_ok(VERIFY_READ, arg->clone_sources,
4435 sizeof(*arg->clone_sources *
4436 arg->clone_sources_count))) {
4437 ret = -EFAULT;
4438 goto out;
4439 }
4440
4441 sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
4442 if (!sctx) {
4443 ret = -ENOMEM;
4444 goto out;
4445 }
4446
4447 INIT_LIST_HEAD(&sctx->new_refs);
4448 INIT_LIST_HEAD(&sctx->deleted_refs);
4449 INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
4450 INIT_LIST_HEAD(&sctx->name_cache_list);
4451
4452 sctx->send_filp = fget(arg->send_fd);
4453 if (IS_ERR(sctx->send_filp)) {
4454 ret = PTR_ERR(sctx->send_filp);
4455 goto out;
4456 }
4457
4458 sctx->mnt = mnt_file->f_path.mnt;
4459
4460 sctx->send_root = send_root;
4461 sctx->clone_roots_cnt = arg->clone_sources_count;
4462
4463 sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
4464 sctx->send_buf = vmalloc(sctx->send_max_size);
4465 if (!sctx->send_buf) {
4466 ret = -ENOMEM;
4467 goto out;
4468 }
4469
4470 sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE);
4471 if (!sctx->read_buf) {
4472 ret = -ENOMEM;
4473 goto out;
4474 }
4475
4476 sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
4477 (arg->clone_sources_count + 1));
4478 if (!sctx->clone_roots) {
4479 ret = -ENOMEM;
4480 goto out;
4481 }
4482
4483 if (arg->clone_sources_count) {
4484 clone_sources_tmp = vmalloc(arg->clone_sources_count *
4485 sizeof(*arg->clone_sources));
4486 if (!clone_sources_tmp) {
4487 ret = -ENOMEM;
4488 goto out;
4489 }
4490
4491 ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
4492 arg->clone_sources_count *
4493 sizeof(*arg->clone_sources));
4494 if (ret) {
4495 ret = -EFAULT;
4496 goto out;
4497 }
4498
4499 for (i = 0; i < arg->clone_sources_count; i++) {
4500 key.objectid = clone_sources_tmp[i];
4501 key.type = BTRFS_ROOT_ITEM_KEY;
4502 key.offset = (u64)-1;
4503 clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
4504 if (!clone_root) {
4505 ret = -EINVAL;
4506 goto out;
4507 }
4508 if (IS_ERR(clone_root)) {
4509 ret = PTR_ERR(clone_root);
4510 goto out;
4511 }
4512 sctx->clone_roots[i].root = clone_root;
4513 }
4514 vfree(clone_sources_tmp);
4515 clone_sources_tmp = NULL;
4516 }
4517
4518 if (arg->parent_root) {
4519 key.objectid = arg->parent_root;
4520 key.type = BTRFS_ROOT_ITEM_KEY;
4521 key.offset = (u64)-1;
4522 sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
4523 if (!sctx->parent_root) {
4524 ret = -EINVAL;
4525 goto out;
4526 }
4527 }
4528
4529 /*
4530 * Clones from send_root are allowed, but only if the clone source
4531 * is behind the current send position. This is checked while searching
4532 * for possible clone sources.
4533 */
4534 sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;
4535
4536 /* We do a bsearch later */
4537 sort(sctx->clone_roots, sctx->clone_roots_cnt,
4538 sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
4539 NULL);
4540
4541 ret = send_subvol(sctx);
4542 if (ret < 0)
4543 goto out;
4544
4545 ret = begin_cmd(sctx, BTRFS_SEND_C_END);
4546 if (ret < 0)
4547 goto out;
4548 ret = send_cmd(sctx);
4549 if (ret < 0)
4550 goto out;
4551
4552 out:
4553 if (filp)
4554 fput(filp);
4555 kfree(arg);
4556 vfree(clone_sources_tmp);
4557
4558 if (sctx) {
4559 if (sctx->send_filp)
4560 fput(sctx->send_filp);
4561
4562 vfree(sctx->clone_roots);
4563 vfree(sctx->send_buf);
4564 vfree(sctx->read_buf);
4565
4566 name_cache_free(sctx);
4567
4568 kfree(sctx);
4569 }
4570
4571 return ret;
4572 }
Linux kernel - Deliverables
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