Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / fs / btrfs / send.c
blob484e2af793de2a86fa206196661d47cda078f0c2
1 /*
2 * Copyright (C) 2012 Alexander Block. All rights reserved.
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.
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.
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.
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/vmalloc.h>
28 #include <linux/string.h>
29 #include <linux/compat.h>
31 #include "send.h"
32 #include "backref.h"
33 #include "hash.h"
34 #include "locking.h"
35 #include "disk-io.h"
36 #include "btrfs_inode.h"
37 #include "transaction.h"
38 #include "compression.h"
41 * A fs_path is a helper to dynamically build path names with unknown size.
42 * It reallocates the internal buffer on demand.
43 * It allows fast adding of path elements on the right side (normal path) and
44 * fast adding to the left side (reversed path). A reversed path can also be
45 * unreversed if needed.
47 struct fs_path {
48 union {
49 struct {
50 char *start;
51 char *end;
53 char *buf;
54 unsigned short buf_len:15;
55 unsigned short reversed:1;
56 char inline_buf[];
59 * Average path length does not exceed 200 bytes, we'll have
60 * better packing in the slab and higher chance to satisfy
61 * a allocation later during send.
63 char pad[256];
66 #define FS_PATH_INLINE_SIZE \
67 (sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
70 /* reused for each extent */
71 struct clone_root {
72 struct btrfs_root *root;
73 u64 ino;
74 u64 offset;
76 u64 found_refs;
79 #define SEND_CTX_MAX_NAME_CACHE_SIZE 128
80 #define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
82 struct send_ctx {
83 struct file *send_filp;
84 loff_t send_off;
85 char *send_buf;
86 u32 send_size;
87 u32 send_max_size;
88 u64 total_send_size;
89 u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
90 u64 flags; /* 'flags' member of btrfs_ioctl_send_args is u64 */
92 struct btrfs_root *send_root;
93 struct btrfs_root *parent_root;
94 struct clone_root *clone_roots;
95 int clone_roots_cnt;
97 /* current state of the compare_tree call */
98 struct btrfs_path *left_path;
99 struct btrfs_path *right_path;
100 struct btrfs_key *cmp_key;
103 * infos of the currently processed inode. In case of deleted inodes,
104 * these are the values from the deleted inode.
106 u64 cur_ino;
107 u64 cur_inode_gen;
108 int cur_inode_new;
109 int cur_inode_new_gen;
110 int cur_inode_deleted;
111 u64 cur_inode_size;
112 u64 cur_inode_mode;
113 u64 cur_inode_rdev;
114 u64 cur_inode_last_extent;
116 u64 send_progress;
118 struct list_head new_refs;
119 struct list_head deleted_refs;
121 struct radix_tree_root name_cache;
122 struct list_head name_cache_list;
123 int name_cache_size;
125 struct file_ra_state ra;
127 char *read_buf;
130 * We process inodes by their increasing order, so if before an
131 * incremental send we reverse the parent/child relationship of
132 * directories such that a directory with a lower inode number was
133 * the parent of a directory with a higher inode number, and the one
134 * becoming the new parent got renamed too, we can't rename/move the
135 * directory with lower inode number when we finish processing it - we
136 * must process the directory with higher inode number first, then
137 * rename/move it and then rename/move the directory with lower inode
138 * number. Example follows.
140 * Tree state when the first send was performed:
143 * |-- a (ino 257)
144 * |-- b (ino 258)
147 * |-- c (ino 259)
148 * | |-- d (ino 260)
150 * |-- c2 (ino 261)
152 * Tree state when the second (incremental) send is performed:
155 * |-- a (ino 257)
156 * |-- b (ino 258)
157 * |-- c2 (ino 261)
158 * |-- d2 (ino 260)
159 * |-- cc (ino 259)
161 * The sequence of steps that lead to the second state was:
163 * mv /a/b/c/d /a/b/c2/d2
164 * mv /a/b/c /a/b/c2/d2/cc
166 * "c" has lower inode number, but we can't move it (2nd mv operation)
167 * before we move "d", which has higher inode number.
169 * So we just memorize which move/rename operations must be performed
170 * later when their respective parent is processed and moved/renamed.
173 /* Indexed by parent directory inode number. */
174 struct rb_root pending_dir_moves;
177 * Reverse index, indexed by the inode number of a directory that
178 * is waiting for the move/rename of its immediate parent before its
179 * own move/rename can be performed.
181 struct rb_root waiting_dir_moves;
184 * A directory that is going to be rm'ed might have a child directory
185 * which is in the pending directory moves index above. In this case,
186 * the directory can only be removed after the move/rename of its child
187 * is performed. Example:
189 * Parent snapshot:
191 * . (ino 256)
192 * |-- a/ (ino 257)
193 * |-- b/ (ino 258)
194 * |-- c/ (ino 259)
195 * | |-- x/ (ino 260)
197 * |-- y/ (ino 261)
199 * Send snapshot:
201 * . (ino 256)
202 * |-- a/ (ino 257)
203 * |-- b/ (ino 258)
204 * |-- YY/ (ino 261)
205 * |-- x/ (ino 260)
207 * Sequence of steps that lead to the send snapshot:
208 * rm -f /a/b/c/foo.txt
209 * mv /a/b/y /a/b/YY
210 * mv /a/b/c/x /a/b/YY
211 * rmdir /a/b/c
213 * When the child is processed, its move/rename is delayed until its
214 * parent is processed (as explained above), but all other operations
215 * like update utimes, chown, chgrp, etc, are performed and the paths
216 * that it uses for those operations must use the orphanized name of
217 * its parent (the directory we're going to rm later), so we need to
218 * memorize that name.
220 * Indexed by the inode number of the directory to be deleted.
222 struct rb_root orphan_dirs;
225 struct pending_dir_move {
226 struct rb_node node;
227 struct list_head list;
228 u64 parent_ino;
229 u64 ino;
230 u64 gen;
231 struct list_head update_refs;
234 struct waiting_dir_move {
235 struct rb_node node;
236 u64 ino;
238 * There might be some directory that could not be removed because it
239 * was waiting for this directory inode to be moved first. Therefore
240 * after this directory is moved, we can try to rmdir the ino rmdir_ino.
242 u64 rmdir_ino;
243 bool orphanized;
246 struct orphan_dir_info {
247 struct rb_node node;
248 u64 ino;
249 u64 gen;
252 struct name_cache_entry {
253 struct list_head list;
255 * radix_tree has only 32bit entries but we need to handle 64bit inums.
256 * We use the lower 32bit of the 64bit inum to store it in the tree. If
257 * more then one inum would fall into the same entry, we use radix_list
258 * to store the additional entries. radix_list is also used to store
259 * entries where two entries have the same inum but different
260 * generations.
262 struct list_head radix_list;
263 u64 ino;
264 u64 gen;
265 u64 parent_ino;
266 u64 parent_gen;
267 int ret;
268 int need_later_update;
269 int name_len;
270 char name[];
273 static void inconsistent_snapshot_error(struct send_ctx *sctx,
274 enum btrfs_compare_tree_result result,
275 const char *what)
277 const char *result_string;
279 switch (result) {
280 case BTRFS_COMPARE_TREE_NEW:
281 result_string = "new";
282 break;
283 case BTRFS_COMPARE_TREE_DELETED:
284 result_string = "deleted";
285 break;
286 case BTRFS_COMPARE_TREE_CHANGED:
287 result_string = "updated";
288 break;
289 case BTRFS_COMPARE_TREE_SAME:
290 ASSERT(0);
291 result_string = "unchanged";
292 break;
293 default:
294 ASSERT(0);
295 result_string = "unexpected";
298 btrfs_err(sctx->send_root->fs_info,
299 "Send: inconsistent snapshot, found %s %s for inode %llu without updated inode item, send root is %llu, parent root is %llu",
300 result_string, what, sctx->cmp_key->objectid,
301 sctx->send_root->root_key.objectid,
302 (sctx->parent_root ?
303 sctx->parent_root->root_key.objectid : 0));
306 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);
308 static struct waiting_dir_move *
309 get_waiting_dir_move(struct send_ctx *sctx, u64 ino);
311 static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino);
313 static int need_send_hole(struct send_ctx *sctx)
315 return (sctx->parent_root && !sctx->cur_inode_new &&
316 !sctx->cur_inode_new_gen && !sctx->cur_inode_deleted &&
317 S_ISREG(sctx->cur_inode_mode));
320 static void fs_path_reset(struct fs_path *p)
322 if (p->reversed) {
323 p->start = p->buf + p->buf_len - 1;
324 p->end = p->start;
325 *p->start = 0;
326 } else {
327 p->start = p->buf;
328 p->end = p->start;
329 *p->start = 0;
333 static struct fs_path *fs_path_alloc(void)
335 struct fs_path *p;
337 p = kmalloc(sizeof(*p), GFP_KERNEL);
338 if (!p)
339 return NULL;
340 p->reversed = 0;
341 p->buf = p->inline_buf;
342 p->buf_len = FS_PATH_INLINE_SIZE;
343 fs_path_reset(p);
344 return p;
347 static struct fs_path *fs_path_alloc_reversed(void)
349 struct fs_path *p;
351 p = fs_path_alloc();
352 if (!p)
353 return NULL;
354 p->reversed = 1;
355 fs_path_reset(p);
356 return p;
359 static void fs_path_free(struct fs_path *p)
361 if (!p)
362 return;
363 if (p->buf != p->inline_buf)
364 kfree(p->buf);
365 kfree(p);
368 static int fs_path_len(struct fs_path *p)
370 return p->end - p->start;
373 static int fs_path_ensure_buf(struct fs_path *p, int len)
375 char *tmp_buf;
376 int path_len;
377 int old_buf_len;
379 len++;
381 if (p->buf_len >= len)
382 return 0;
384 if (len > PATH_MAX) {
385 WARN_ON(1);
386 return -ENOMEM;
389 path_len = p->end - p->start;
390 old_buf_len = p->buf_len;
393 * First time the inline_buf does not suffice
395 if (p->buf == p->inline_buf) {
396 tmp_buf = kmalloc(len, GFP_KERNEL);
397 if (tmp_buf)
398 memcpy(tmp_buf, p->buf, old_buf_len);
399 } else {
400 tmp_buf = krealloc(p->buf, len, GFP_KERNEL);
402 if (!tmp_buf)
403 return -ENOMEM;
404 p->buf = tmp_buf;
406 * The real size of the buffer is bigger, this will let the fast path
407 * happen most of the time
409 p->buf_len = ksize(p->buf);
411 if (p->reversed) {
412 tmp_buf = p->buf + old_buf_len - path_len - 1;
413 p->end = p->buf + p->buf_len - 1;
414 p->start = p->end - path_len;
415 memmove(p->start, tmp_buf, path_len + 1);
416 } else {
417 p->start = p->buf;
418 p->end = p->start + path_len;
420 return 0;
423 static int fs_path_prepare_for_add(struct fs_path *p, int name_len,
424 char **prepared)
426 int ret;
427 int new_len;
429 new_len = p->end - p->start + name_len;
430 if (p->start != p->end)
431 new_len++;
432 ret = fs_path_ensure_buf(p, new_len);
433 if (ret < 0)
434 goto out;
436 if (p->reversed) {
437 if (p->start != p->end)
438 *--p->start = '/';
439 p->start -= name_len;
440 *prepared = p->start;
441 } else {
442 if (p->start != p->end)
443 *p->end++ = '/';
444 *prepared = p->end;
445 p->end += name_len;
446 *p->end = 0;
449 out:
450 return ret;
453 static int fs_path_add(struct fs_path *p, const char *name, int name_len)
455 int ret;
456 char *prepared;
458 ret = fs_path_prepare_for_add(p, name_len, &prepared);
459 if (ret < 0)
460 goto out;
461 memcpy(prepared, name, name_len);
463 out:
464 return ret;
467 static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
469 int ret;
470 char *prepared;
472 ret = fs_path_prepare_for_add(p, p2->end - p2->start, &prepared);
473 if (ret < 0)
474 goto out;
475 memcpy(prepared, p2->start, p2->end - p2->start);
477 out:
478 return ret;
481 static int fs_path_add_from_extent_buffer(struct fs_path *p,
482 struct extent_buffer *eb,
483 unsigned long off, int len)
485 int ret;
486 char *prepared;
488 ret = fs_path_prepare_for_add(p, len, &prepared);
489 if (ret < 0)
490 goto out;
492 read_extent_buffer(eb, prepared, off, len);
494 out:
495 return ret;
498 static int fs_path_copy(struct fs_path *p, struct fs_path *from)
500 int ret;
502 p->reversed = from->reversed;
503 fs_path_reset(p);
505 ret = fs_path_add_path(p, from);
507 return ret;
511 static void fs_path_unreverse(struct fs_path *p)
513 char *tmp;
514 int len;
516 if (!p->reversed)
517 return;
519 tmp = p->start;
520 len = p->end - p->start;
521 p->start = p->buf;
522 p->end = p->start + len;
523 memmove(p->start, tmp, len + 1);
524 p->reversed = 0;
527 static struct btrfs_path *alloc_path_for_send(void)
529 struct btrfs_path *path;
531 path = btrfs_alloc_path();
532 if (!path)
533 return NULL;
534 path->search_commit_root = 1;
535 path->skip_locking = 1;
536 path->need_commit_sem = 1;
537 return path;
540 static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
542 int ret;
543 u32 pos = 0;
545 while (pos < len) {
546 ret = kernel_write(filp, buf + pos, len - pos, off);
547 /* TODO handle that correctly */
548 /*if (ret == -ERESTARTSYS) {
549 continue;
551 if (ret < 0)
552 return ret;
553 if (ret == 0) {
554 return -EIO;
556 pos += ret;
559 return 0;
562 static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
564 struct btrfs_tlv_header *hdr;
565 int total_len = sizeof(*hdr) + len;
566 int left = sctx->send_max_size - sctx->send_size;
568 if (unlikely(left < total_len))
569 return -EOVERFLOW;
571 hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
572 hdr->tlv_type = cpu_to_le16(attr);
573 hdr->tlv_len = cpu_to_le16(len);
574 memcpy(hdr + 1, data, len);
575 sctx->send_size += total_len;
577 return 0;
580 #define TLV_PUT_DEFINE_INT(bits) \
581 static int tlv_put_u##bits(struct send_ctx *sctx, \
582 u##bits attr, u##bits value) \
584 __le##bits __tmp = cpu_to_le##bits(value); \
585 return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \
588 TLV_PUT_DEFINE_INT(64)
590 static int tlv_put_string(struct send_ctx *sctx, u16 attr,
591 const char *str, int len)
593 if (len == -1)
594 len = strlen(str);
595 return tlv_put(sctx, attr, str, len);
598 static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
599 const u8 *uuid)
601 return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
604 static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
605 struct extent_buffer *eb,
606 struct btrfs_timespec *ts)
608 struct btrfs_timespec bts;
609 read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
610 return tlv_put(sctx, attr, &bts, sizeof(bts));
614 #define TLV_PUT(sctx, attrtype, attrlen, data) \
615 do { \
616 ret = tlv_put(sctx, attrtype, attrlen, data); \
617 if (ret < 0) \
618 goto tlv_put_failure; \
619 } while (0)
621 #define TLV_PUT_INT(sctx, attrtype, bits, value) \
622 do { \
623 ret = tlv_put_u##bits(sctx, attrtype, value); \
624 if (ret < 0) \
625 goto tlv_put_failure; \
626 } while (0)
628 #define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
629 #define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
630 #define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
631 #define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
632 #define TLV_PUT_STRING(sctx, attrtype, str, len) \
633 do { \
634 ret = tlv_put_string(sctx, attrtype, str, len); \
635 if (ret < 0) \
636 goto tlv_put_failure; \
637 } while (0)
638 #define TLV_PUT_PATH(sctx, attrtype, p) \
639 do { \
640 ret = tlv_put_string(sctx, attrtype, p->start, \
641 p->end - p->start); \
642 if (ret < 0) \
643 goto tlv_put_failure; \
644 } while(0)
645 #define TLV_PUT_UUID(sctx, attrtype, uuid) \
646 do { \
647 ret = tlv_put_uuid(sctx, attrtype, uuid); \
648 if (ret < 0) \
649 goto tlv_put_failure; \
650 } while (0)
651 #define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
652 do { \
653 ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
654 if (ret < 0) \
655 goto tlv_put_failure; \
656 } while (0)
658 static int send_header(struct send_ctx *sctx)
660 struct btrfs_stream_header hdr;
662 strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
663 hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
665 return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
666 &sctx->send_off);
670 * For each command/item we want to send to userspace, we call this function.
672 static int begin_cmd(struct send_ctx *sctx, int cmd)
674 struct btrfs_cmd_header *hdr;
676 if (WARN_ON(!sctx->send_buf))
677 return -EINVAL;
679 BUG_ON(sctx->send_size);
681 sctx->send_size += sizeof(*hdr);
682 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
683 hdr->cmd = cpu_to_le16(cmd);
685 return 0;
688 static int send_cmd(struct send_ctx *sctx)
690 int ret;
691 struct btrfs_cmd_header *hdr;
692 u32 crc;
694 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
695 hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
696 hdr->crc = 0;
698 crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
699 hdr->crc = cpu_to_le32(crc);
701 ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
702 &sctx->send_off);
704 sctx->total_send_size += sctx->send_size;
705 sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
706 sctx->send_size = 0;
708 return ret;
712 * Sends a move instruction to user space
714 static int send_rename(struct send_ctx *sctx,
715 struct fs_path *from, struct fs_path *to)
717 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
718 int ret;
720 btrfs_debug(fs_info, "send_rename %s -> %s", from->start, to->start);
722 ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
723 if (ret < 0)
724 goto out;
726 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
727 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
729 ret = send_cmd(sctx);
731 tlv_put_failure:
732 out:
733 return ret;
737 * Sends a link instruction to user space
739 static int send_link(struct send_ctx *sctx,
740 struct fs_path *path, struct fs_path *lnk)
742 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
743 int ret;
745 btrfs_debug(fs_info, "send_link %s -> %s", path->start, lnk->start);
747 ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
748 if (ret < 0)
749 goto out;
751 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
752 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
754 ret = send_cmd(sctx);
756 tlv_put_failure:
757 out:
758 return ret;
762 * Sends an unlink instruction to user space
764 static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
766 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
767 int ret;
769 btrfs_debug(fs_info, "send_unlink %s", path->start);
771 ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
772 if (ret < 0)
773 goto out;
775 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
777 ret = send_cmd(sctx);
779 tlv_put_failure:
780 out:
781 return ret;
785 * Sends a rmdir instruction to user space
787 static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
789 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
790 int ret;
792 btrfs_debug(fs_info, "send_rmdir %s", path->start);
794 ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
795 if (ret < 0)
796 goto out;
798 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
800 ret = send_cmd(sctx);
802 tlv_put_failure:
803 out:
804 return ret;
808 * Helper function to retrieve some fields from an inode item.
810 static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
811 u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid,
812 u64 *gid, u64 *rdev)
814 int ret;
815 struct btrfs_inode_item *ii;
816 struct btrfs_key key;
818 key.objectid = ino;
819 key.type = BTRFS_INODE_ITEM_KEY;
820 key.offset = 0;
821 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
822 if (ret) {
823 if (ret > 0)
824 ret = -ENOENT;
825 return ret;
828 ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
829 struct btrfs_inode_item);
830 if (size)
831 *size = btrfs_inode_size(path->nodes[0], ii);
832 if (gen)
833 *gen = btrfs_inode_generation(path->nodes[0], ii);
834 if (mode)
835 *mode = btrfs_inode_mode(path->nodes[0], ii);
836 if (uid)
837 *uid = btrfs_inode_uid(path->nodes[0], ii);
838 if (gid)
839 *gid = btrfs_inode_gid(path->nodes[0], ii);
840 if (rdev)
841 *rdev = btrfs_inode_rdev(path->nodes[0], ii);
843 return ret;
846 static int get_inode_info(struct btrfs_root *root,
847 u64 ino, u64 *size, u64 *gen,
848 u64 *mode, u64 *uid, u64 *gid,
849 u64 *rdev)
851 struct btrfs_path *path;
852 int ret;
854 path = alloc_path_for_send();
855 if (!path)
856 return -ENOMEM;
857 ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid,
858 rdev);
859 btrfs_free_path(path);
860 return ret;
863 typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
864 struct fs_path *p,
865 void *ctx);
868 * Helper function to iterate the entries in ONE btrfs_inode_ref or
869 * btrfs_inode_extref.
870 * The iterate callback may return a non zero value to stop iteration. This can
871 * be a negative value for error codes or 1 to simply stop it.
873 * path must point to the INODE_REF or INODE_EXTREF when called.
875 static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
876 struct btrfs_key *found_key, int resolve,
877 iterate_inode_ref_t iterate, void *ctx)
879 struct extent_buffer *eb = path->nodes[0];
880 struct btrfs_item *item;
881 struct btrfs_inode_ref *iref;
882 struct btrfs_inode_extref *extref;
883 struct btrfs_path *tmp_path;
884 struct fs_path *p;
885 u32 cur = 0;
886 u32 total;
887 int slot = path->slots[0];
888 u32 name_len;
889 char *start;
890 int ret = 0;
891 int num = 0;
892 int index;
893 u64 dir;
894 unsigned long name_off;
895 unsigned long elem_size;
896 unsigned long ptr;
898 p = fs_path_alloc_reversed();
899 if (!p)
900 return -ENOMEM;
902 tmp_path = alloc_path_for_send();
903 if (!tmp_path) {
904 fs_path_free(p);
905 return -ENOMEM;
909 if (found_key->type == BTRFS_INODE_REF_KEY) {
910 ptr = (unsigned long)btrfs_item_ptr(eb, slot,
911 struct btrfs_inode_ref);
912 item = btrfs_item_nr(slot);
913 total = btrfs_item_size(eb, item);
914 elem_size = sizeof(*iref);
915 } else {
916 ptr = btrfs_item_ptr_offset(eb, slot);
917 total = btrfs_item_size_nr(eb, slot);
918 elem_size = sizeof(*extref);
921 while (cur < total) {
922 fs_path_reset(p);
924 if (found_key->type == BTRFS_INODE_REF_KEY) {
925 iref = (struct btrfs_inode_ref *)(ptr + cur);
926 name_len = btrfs_inode_ref_name_len(eb, iref);
927 name_off = (unsigned long)(iref + 1);
928 index = btrfs_inode_ref_index(eb, iref);
929 dir = found_key->offset;
930 } else {
931 extref = (struct btrfs_inode_extref *)(ptr + cur);
932 name_len = btrfs_inode_extref_name_len(eb, extref);
933 name_off = (unsigned long)&extref->name;
934 index = btrfs_inode_extref_index(eb, extref);
935 dir = btrfs_inode_extref_parent(eb, extref);
938 if (resolve) {
939 start = btrfs_ref_to_path(root, tmp_path, name_len,
940 name_off, eb, dir,
941 p->buf, p->buf_len);
942 if (IS_ERR(start)) {
943 ret = PTR_ERR(start);
944 goto out;
946 if (start < p->buf) {
947 /* overflow , try again with larger buffer */
948 ret = fs_path_ensure_buf(p,
949 p->buf_len + p->buf - start);
950 if (ret < 0)
951 goto out;
952 start = btrfs_ref_to_path(root, tmp_path,
953 name_len, name_off,
954 eb, dir,
955 p->buf, p->buf_len);
956 if (IS_ERR(start)) {
957 ret = PTR_ERR(start);
958 goto out;
960 BUG_ON(start < p->buf);
962 p->start = start;
963 } else {
964 ret = fs_path_add_from_extent_buffer(p, eb, name_off,
965 name_len);
966 if (ret < 0)
967 goto out;
970 cur += elem_size + name_len;
971 ret = iterate(num, dir, index, p, ctx);
972 if (ret)
973 goto out;
974 num++;
977 out:
978 btrfs_free_path(tmp_path);
979 fs_path_free(p);
980 return ret;
983 typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
984 const char *name, int name_len,
985 const char *data, int data_len,
986 u8 type, void *ctx);
989 * Helper function to iterate the entries in ONE btrfs_dir_item.
990 * The iterate callback may return a non zero value to stop iteration. This can
991 * be a negative value for error codes or 1 to simply stop it.
993 * path must point to the dir item when called.
995 static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
996 iterate_dir_item_t iterate, void *ctx)
998 int ret = 0;
999 struct extent_buffer *eb;
1000 struct btrfs_item *item;
1001 struct btrfs_dir_item *di;
1002 struct btrfs_key di_key;
1003 char *buf = NULL;
1004 int buf_len;
1005 u32 name_len;
1006 u32 data_len;
1007 u32 cur;
1008 u32 len;
1009 u32 total;
1010 int slot;
1011 int num;
1012 u8 type;
1015 * Start with a small buffer (1 page). If later we end up needing more
1016 * space, which can happen for xattrs on a fs with a leaf size greater
1017 * then the page size, attempt to increase the buffer. Typically xattr
1018 * values are small.
1020 buf_len = PATH_MAX;
1021 buf = kmalloc(buf_len, GFP_KERNEL);
1022 if (!buf) {
1023 ret = -ENOMEM;
1024 goto out;
1027 eb = path->nodes[0];
1028 slot = path->slots[0];
1029 item = btrfs_item_nr(slot);
1030 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
1031 cur = 0;
1032 len = 0;
1033 total = btrfs_item_size(eb, item);
1035 num = 0;
1036 while (cur < total) {
1037 name_len = btrfs_dir_name_len(eb, di);
1038 data_len = btrfs_dir_data_len(eb, di);
1039 type = btrfs_dir_type(eb, di);
1040 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
1042 if (type == BTRFS_FT_XATTR) {
1043 if (name_len > XATTR_NAME_MAX) {
1044 ret = -ENAMETOOLONG;
1045 goto out;
1047 if (name_len + data_len >
1048 BTRFS_MAX_XATTR_SIZE(root->fs_info)) {
1049 ret = -E2BIG;
1050 goto out;
1052 } else {
1054 * Path too long
1056 if (name_len + data_len > PATH_MAX) {
1057 ret = -ENAMETOOLONG;
1058 goto out;
1062 if (name_len + data_len > buf_len) {
1063 buf_len = name_len + data_len;
1064 if (is_vmalloc_addr(buf)) {
1065 vfree(buf);
1066 buf = NULL;
1067 } else {
1068 char *tmp = krealloc(buf, buf_len,
1069 GFP_KERNEL | __GFP_NOWARN);
1071 if (!tmp)
1072 kfree(buf);
1073 buf = tmp;
1075 if (!buf) {
1076 buf = kvmalloc(buf_len, GFP_KERNEL);
1077 if (!buf) {
1078 ret = -ENOMEM;
1079 goto out;
1084 read_extent_buffer(eb, buf, (unsigned long)(di + 1),
1085 name_len + data_len);
1087 len = sizeof(*di) + name_len + data_len;
1088 di = (struct btrfs_dir_item *)((char *)di + len);
1089 cur += len;
1091 ret = iterate(num, &di_key, buf, name_len, buf + name_len,
1092 data_len, type, ctx);
1093 if (ret < 0)
1094 goto out;
1095 if (ret) {
1096 ret = 0;
1097 goto out;
1100 num++;
1103 out:
1104 kvfree(buf);
1105 return ret;
1108 static int __copy_first_ref(int num, u64 dir, int index,
1109 struct fs_path *p, void *ctx)
1111 int ret;
1112 struct fs_path *pt = ctx;
1114 ret = fs_path_copy(pt, p);
1115 if (ret < 0)
1116 return ret;
1118 /* we want the first only */
1119 return 1;
1123 * Retrieve the first path of an inode. If an inode has more then one
1124 * ref/hardlink, this is ignored.
1126 static int get_inode_path(struct btrfs_root *root,
1127 u64 ino, struct fs_path *path)
1129 int ret;
1130 struct btrfs_key key, found_key;
1131 struct btrfs_path *p;
1133 p = alloc_path_for_send();
1134 if (!p)
1135 return -ENOMEM;
1137 fs_path_reset(path);
1139 key.objectid = ino;
1140 key.type = BTRFS_INODE_REF_KEY;
1141 key.offset = 0;
1143 ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
1144 if (ret < 0)
1145 goto out;
1146 if (ret) {
1147 ret = 1;
1148 goto out;
1150 btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
1151 if (found_key.objectid != ino ||
1152 (found_key.type != BTRFS_INODE_REF_KEY &&
1153 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1154 ret = -ENOENT;
1155 goto out;
1158 ret = iterate_inode_ref(root, p, &found_key, 1,
1159 __copy_first_ref, path);
1160 if (ret < 0)
1161 goto out;
1162 ret = 0;
1164 out:
1165 btrfs_free_path(p);
1166 return ret;
1169 struct backref_ctx {
1170 struct send_ctx *sctx;
1172 struct btrfs_path *path;
1173 /* number of total found references */
1174 u64 found;
1177 * used for clones found in send_root. clones found behind cur_objectid
1178 * and cur_offset are not considered as allowed clones.
1180 u64 cur_objectid;
1181 u64 cur_offset;
1183 /* may be truncated in case it's the last extent in a file */
1184 u64 extent_len;
1186 /* data offset in the file extent item */
1187 u64 data_offset;
1189 /* Just to check for bugs in backref resolving */
1190 int found_itself;
1193 static int __clone_root_cmp_bsearch(const void *key, const void *elt)
1195 u64 root = (u64)(uintptr_t)key;
1196 struct clone_root *cr = (struct clone_root *)elt;
1198 if (root < cr->root->objectid)
1199 return -1;
1200 if (root > cr->root->objectid)
1201 return 1;
1202 return 0;
1205 static int __clone_root_cmp_sort(const void *e1, const void *e2)
1207 struct clone_root *cr1 = (struct clone_root *)e1;
1208 struct clone_root *cr2 = (struct clone_root *)e2;
1210 if (cr1->root->objectid < cr2->root->objectid)
1211 return -1;
1212 if (cr1->root->objectid > cr2->root->objectid)
1213 return 1;
1214 return 0;
1218 * Called for every backref that is found for the current extent.
1219 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1221 static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
1223 struct backref_ctx *bctx = ctx_;
1224 struct clone_root *found;
1225 int ret;
1226 u64 i_size;
1228 /* First check if the root is in the list of accepted clone sources */
1229 found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1230 bctx->sctx->clone_roots_cnt,
1231 sizeof(struct clone_root),
1232 __clone_root_cmp_bsearch);
1233 if (!found)
1234 return 0;
1236 if (found->root == bctx->sctx->send_root &&
1237 ino == bctx->cur_objectid &&
1238 offset == bctx->cur_offset) {
1239 bctx->found_itself = 1;
1243 * There are inodes that have extents that lie behind its i_size. Don't
1244 * accept clones from these extents.
1246 ret = __get_inode_info(found->root, bctx->path, ino, &i_size, NULL, NULL,
1247 NULL, NULL, NULL);
1248 btrfs_release_path(bctx->path);
1249 if (ret < 0)
1250 return ret;
1252 if (offset + bctx->data_offset + bctx->extent_len > i_size)
1253 return 0;
1256 * Make sure we don't consider clones from send_root that are
1257 * behind the current inode/offset.
1259 if (found->root == bctx->sctx->send_root) {
1261 * TODO for the moment we don't accept clones from the inode
1262 * that is currently send. We may change this when
1263 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1264 * file.
1266 if (ino >= bctx->cur_objectid)
1267 return 0;
1270 bctx->found++;
1271 found->found_refs++;
1272 if (ino < found->ino) {
1273 found->ino = ino;
1274 found->offset = offset;
1275 } else if (found->ino == ino) {
1277 * same extent found more then once in the same file.
1279 if (found->offset > offset + bctx->extent_len)
1280 found->offset = offset;
1283 return 0;
1287 * Given an inode, offset and extent item, it finds a good clone for a clone
1288 * instruction. Returns -ENOENT when none could be found. The function makes
1289 * sure that the returned clone is usable at the point where sending is at the
1290 * moment. This means, that no clones are accepted which lie behind the current
1291 * inode+offset.
1293 * path must point to the extent item when called.
1295 static int find_extent_clone(struct send_ctx *sctx,
1296 struct btrfs_path *path,
1297 u64 ino, u64 data_offset,
1298 u64 ino_size,
1299 struct clone_root **found)
1301 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
1302 int ret;
1303 int extent_type;
1304 u64 logical;
1305 u64 disk_byte;
1306 u64 num_bytes;
1307 u64 extent_item_pos;
1308 u64 flags = 0;
1309 struct btrfs_file_extent_item *fi;
1310 struct extent_buffer *eb = path->nodes[0];
1311 struct backref_ctx *backref_ctx = NULL;
1312 struct clone_root *cur_clone_root;
1313 struct btrfs_key found_key;
1314 struct btrfs_path *tmp_path;
1315 int compressed;
1316 u32 i;
1318 tmp_path = alloc_path_for_send();
1319 if (!tmp_path)
1320 return -ENOMEM;
1322 /* We only use this path under the commit sem */
1323 tmp_path->need_commit_sem = 0;
1325 backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_KERNEL);
1326 if (!backref_ctx) {
1327 ret = -ENOMEM;
1328 goto out;
1331 backref_ctx->path = tmp_path;
1333 if (data_offset >= ino_size) {
1335 * There may be extents that lie behind the file's size.
1336 * I at least had this in combination with snapshotting while
1337 * writing large files.
1339 ret = 0;
1340 goto out;
1343 fi = btrfs_item_ptr(eb, path->slots[0],
1344 struct btrfs_file_extent_item);
1345 extent_type = btrfs_file_extent_type(eb, fi);
1346 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1347 ret = -ENOENT;
1348 goto out;
1350 compressed = btrfs_file_extent_compression(eb, fi);
1352 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1353 disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
1354 if (disk_byte == 0) {
1355 ret = -ENOENT;
1356 goto out;
1358 logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1360 down_read(&fs_info->commit_root_sem);
1361 ret = extent_from_logical(fs_info, disk_byte, tmp_path,
1362 &found_key, &flags);
1363 up_read(&fs_info->commit_root_sem);
1364 btrfs_release_path(tmp_path);
1366 if (ret < 0)
1367 goto out;
1368 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1369 ret = -EIO;
1370 goto out;
1374 * Setup the clone roots.
1376 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1377 cur_clone_root = sctx->clone_roots + i;
1378 cur_clone_root->ino = (u64)-1;
1379 cur_clone_root->offset = 0;
1380 cur_clone_root->found_refs = 0;
1383 backref_ctx->sctx = sctx;
1384 backref_ctx->found = 0;
1385 backref_ctx->cur_objectid = ino;
1386 backref_ctx->cur_offset = data_offset;
1387 backref_ctx->found_itself = 0;
1388 backref_ctx->extent_len = num_bytes;
1390 * For non-compressed extents iterate_extent_inodes() gives us extent
1391 * offsets that already take into account the data offset, but not for
1392 * compressed extents, since the offset is logical and not relative to
1393 * the physical extent locations. We must take this into account to
1394 * avoid sending clone offsets that go beyond the source file's size,
1395 * which would result in the clone ioctl failing with -EINVAL on the
1396 * receiving end.
1398 if (compressed == BTRFS_COMPRESS_NONE)
1399 backref_ctx->data_offset = 0;
1400 else
1401 backref_ctx->data_offset = btrfs_file_extent_offset(eb, fi);
1404 * The last extent of a file may be too large due to page alignment.
1405 * We need to adjust extent_len in this case so that the checks in
1406 * __iterate_backrefs work.
1408 if (data_offset + num_bytes >= ino_size)
1409 backref_ctx->extent_len = ino_size - data_offset;
1412 * Now collect all backrefs.
1414 if (compressed == BTRFS_COMPRESS_NONE)
1415 extent_item_pos = logical - found_key.objectid;
1416 else
1417 extent_item_pos = 0;
1418 ret = iterate_extent_inodes(fs_info, found_key.objectid,
1419 extent_item_pos, 1, __iterate_backrefs,
1420 backref_ctx, false);
1422 if (ret < 0)
1423 goto out;
1425 if (!backref_ctx->found_itself) {
1426 /* found a bug in backref code? */
1427 ret = -EIO;
1428 btrfs_err(fs_info,
1429 "did not find backref in send_root. inode=%llu, offset=%llu, disk_byte=%llu found extent=%llu",
1430 ino, data_offset, disk_byte, found_key.objectid);
1431 goto out;
1434 btrfs_debug(fs_info,
1435 "find_extent_clone: data_offset=%llu, ino=%llu, num_bytes=%llu, logical=%llu",
1436 data_offset, ino, num_bytes, logical);
1438 if (!backref_ctx->found)
1439 btrfs_debug(fs_info, "no clones found");
1441 cur_clone_root = NULL;
1442 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1443 if (sctx->clone_roots[i].found_refs) {
1444 if (!cur_clone_root)
1445 cur_clone_root = sctx->clone_roots + i;
1446 else if (sctx->clone_roots[i].root == sctx->send_root)
1447 /* prefer clones from send_root over others */
1448 cur_clone_root = sctx->clone_roots + i;
1453 if (cur_clone_root) {
1454 *found = cur_clone_root;
1455 ret = 0;
1456 } else {
1457 ret = -ENOENT;
1460 out:
1461 btrfs_free_path(tmp_path);
1462 kfree(backref_ctx);
1463 return ret;
1466 static int read_symlink(struct btrfs_root *root,
1467 u64 ino,
1468 struct fs_path *dest)
1470 int ret;
1471 struct btrfs_path *path;
1472 struct btrfs_key key;
1473 struct btrfs_file_extent_item *ei;
1474 u8 type;
1475 u8 compression;
1476 unsigned long off;
1477 int len;
1479 path = alloc_path_for_send();
1480 if (!path)
1481 return -ENOMEM;
1483 key.objectid = ino;
1484 key.type = BTRFS_EXTENT_DATA_KEY;
1485 key.offset = 0;
1486 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1487 if (ret < 0)
1488 goto out;
1489 if (ret) {
1491 * An empty symlink inode. Can happen in rare error paths when
1492 * creating a symlink (transaction committed before the inode
1493 * eviction handler removed the symlink inode items and a crash
1494 * happened in between or the subvol was snapshoted in between).
1495 * Print an informative message to dmesg/syslog so that the user
1496 * can delete the symlink.
1498 btrfs_err(root->fs_info,
1499 "Found empty symlink inode %llu at root %llu",
1500 ino, root->root_key.objectid);
1501 ret = -EIO;
1502 goto out;
1505 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
1506 struct btrfs_file_extent_item);
1507 type = btrfs_file_extent_type(path->nodes[0], ei);
1508 compression = btrfs_file_extent_compression(path->nodes[0], ei);
1509 BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
1510 BUG_ON(compression);
1512 off = btrfs_file_extent_inline_start(ei);
1513 len = btrfs_file_extent_inline_len(path->nodes[0], path->slots[0], ei);
1515 ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
1517 out:
1518 btrfs_free_path(path);
1519 return ret;
1523 * Helper function to generate a file name that is unique in the root of
1524 * send_root and parent_root. This is used to generate names for orphan inodes.
1526 static int gen_unique_name(struct send_ctx *sctx,
1527 u64 ino, u64 gen,
1528 struct fs_path *dest)
1530 int ret = 0;
1531 struct btrfs_path *path;
1532 struct btrfs_dir_item *di;
1533 char tmp[64];
1534 int len;
1535 u64 idx = 0;
1537 path = alloc_path_for_send();
1538 if (!path)
1539 return -ENOMEM;
1541 while (1) {
1542 len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
1543 ino, gen, idx);
1544 ASSERT(len < sizeof(tmp));
1546 di = btrfs_lookup_dir_item(NULL, sctx->send_root,
1547 path, BTRFS_FIRST_FREE_OBJECTID,
1548 tmp, strlen(tmp), 0);
1549 btrfs_release_path(path);
1550 if (IS_ERR(di)) {
1551 ret = PTR_ERR(di);
1552 goto out;
1554 if (di) {
1555 /* not unique, try again */
1556 idx++;
1557 continue;
1560 if (!sctx->parent_root) {
1561 /* unique */
1562 ret = 0;
1563 break;
1566 di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
1567 path, BTRFS_FIRST_FREE_OBJECTID,
1568 tmp, strlen(tmp), 0);
1569 btrfs_release_path(path);
1570 if (IS_ERR(di)) {
1571 ret = PTR_ERR(di);
1572 goto out;
1574 if (di) {
1575 /* not unique, try again */
1576 idx++;
1577 continue;
1579 /* unique */
1580 break;
1583 ret = fs_path_add(dest, tmp, strlen(tmp));
1585 out:
1586 btrfs_free_path(path);
1587 return ret;
1590 enum inode_state {
1591 inode_state_no_change,
1592 inode_state_will_create,
1593 inode_state_did_create,
1594 inode_state_will_delete,
1595 inode_state_did_delete,
1598 static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
1600 int ret;
1601 int left_ret;
1602 int right_ret;
1603 u64 left_gen;
1604 u64 right_gen;
1606 ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1607 NULL, NULL);
1608 if (ret < 0 && ret != -ENOENT)
1609 goto out;
1610 left_ret = ret;
1612 if (!sctx->parent_root) {
1613 right_ret = -ENOENT;
1614 } else {
1615 ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1616 NULL, NULL, NULL, NULL);
1617 if (ret < 0 && ret != -ENOENT)
1618 goto out;
1619 right_ret = ret;
1622 if (!left_ret && !right_ret) {
1623 if (left_gen == gen && right_gen == gen) {
1624 ret = inode_state_no_change;
1625 } else if (left_gen == gen) {
1626 if (ino < sctx->send_progress)
1627 ret = inode_state_did_create;
1628 else
1629 ret = inode_state_will_create;
1630 } else if (right_gen == gen) {
1631 if (ino < sctx->send_progress)
1632 ret = inode_state_did_delete;
1633 else
1634 ret = inode_state_will_delete;
1635 } else {
1636 ret = -ENOENT;
1638 } else if (!left_ret) {
1639 if (left_gen == gen) {
1640 if (ino < sctx->send_progress)
1641 ret = inode_state_did_create;
1642 else
1643 ret = inode_state_will_create;
1644 } else {
1645 ret = -ENOENT;
1647 } else if (!right_ret) {
1648 if (right_gen == gen) {
1649 if (ino < sctx->send_progress)
1650 ret = inode_state_did_delete;
1651 else
1652 ret = inode_state_will_delete;
1653 } else {
1654 ret = -ENOENT;
1656 } else {
1657 ret = -ENOENT;
1660 out:
1661 return ret;
1664 static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
1666 int ret;
1668 if (ino == BTRFS_FIRST_FREE_OBJECTID)
1669 return 1;
1671 ret = get_cur_inode_state(sctx, ino, gen);
1672 if (ret < 0)
1673 goto out;
1675 if (ret == inode_state_no_change ||
1676 ret == inode_state_did_create ||
1677 ret == inode_state_will_delete)
1678 ret = 1;
1679 else
1680 ret = 0;
1682 out:
1683 return ret;
1687 * Helper function to lookup a dir item in a dir.
1689 static int lookup_dir_item_inode(struct btrfs_root *root,
1690 u64 dir, const char *name, int name_len,
1691 u64 *found_inode,
1692 u8 *found_type)
1694 int ret = 0;
1695 struct btrfs_dir_item *di;
1696 struct btrfs_key key;
1697 struct btrfs_path *path;
1699 path = alloc_path_for_send();
1700 if (!path)
1701 return -ENOMEM;
1703 di = btrfs_lookup_dir_item(NULL, root, path,
1704 dir, name, name_len, 0);
1705 if (!di) {
1706 ret = -ENOENT;
1707 goto out;
1709 if (IS_ERR(di)) {
1710 ret = PTR_ERR(di);
1711 goto out;
1713 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1714 if (key.type == BTRFS_ROOT_ITEM_KEY) {
1715 ret = -ENOENT;
1716 goto out;
1718 *found_inode = key.objectid;
1719 *found_type = btrfs_dir_type(path->nodes[0], di);
1721 out:
1722 btrfs_free_path(path);
1723 return ret;
1727 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
1728 * generation of the parent dir and the name of the dir entry.
1730 static int get_first_ref(struct btrfs_root *root, u64 ino,
1731 u64 *dir, u64 *dir_gen, struct fs_path *name)
1733 int ret;
1734 struct btrfs_key key;
1735 struct btrfs_key found_key;
1736 struct btrfs_path *path;
1737 int len;
1738 u64 parent_dir;
1740 path = alloc_path_for_send();
1741 if (!path)
1742 return -ENOMEM;
1744 key.objectid = ino;
1745 key.type = BTRFS_INODE_REF_KEY;
1746 key.offset = 0;
1748 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
1749 if (ret < 0)
1750 goto out;
1751 if (!ret)
1752 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1753 path->slots[0]);
1754 if (ret || found_key.objectid != ino ||
1755 (found_key.type != BTRFS_INODE_REF_KEY &&
1756 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1757 ret = -ENOENT;
1758 goto out;
1761 if (found_key.type == BTRFS_INODE_REF_KEY) {
1762 struct btrfs_inode_ref *iref;
1763 iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1764 struct btrfs_inode_ref);
1765 len = btrfs_inode_ref_name_len(path->nodes[0], iref);
1766 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1767 (unsigned long)(iref + 1),
1768 len);
1769 parent_dir = found_key.offset;
1770 } else {
1771 struct btrfs_inode_extref *extref;
1772 extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1773 struct btrfs_inode_extref);
1774 len = btrfs_inode_extref_name_len(path->nodes[0], extref);
1775 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1776 (unsigned long)&extref->name, len);
1777 parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
1779 if (ret < 0)
1780 goto out;
1781 btrfs_release_path(path);
1783 if (dir_gen) {
1784 ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL,
1785 NULL, NULL, NULL);
1786 if (ret < 0)
1787 goto out;
1790 *dir = parent_dir;
1792 out:
1793 btrfs_free_path(path);
1794 return ret;
1797 static int is_first_ref(struct btrfs_root *root,
1798 u64 ino, u64 dir,
1799 const char *name, int name_len)
1801 int ret;
1802 struct fs_path *tmp_name;
1803 u64 tmp_dir;
1805 tmp_name = fs_path_alloc();
1806 if (!tmp_name)
1807 return -ENOMEM;
1809 ret = get_first_ref(root, ino, &tmp_dir, NULL, tmp_name);
1810 if (ret < 0)
1811 goto out;
1813 if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1814 ret = 0;
1815 goto out;
1818 ret = !memcmp(tmp_name->start, name, name_len);
1820 out:
1821 fs_path_free(tmp_name);
1822 return ret;
1826 * Used by process_recorded_refs to determine if a new ref would overwrite an
1827 * already existing ref. In case it detects an overwrite, it returns the
1828 * inode/gen in who_ino/who_gen.
1829 * When an overwrite is detected, process_recorded_refs does proper orphanizing
1830 * to make sure later references to the overwritten inode are possible.
1831 * Orphanizing is however only required for the first ref of an inode.
1832 * process_recorded_refs does an additional is_first_ref check to see if
1833 * orphanizing is really required.
1835 static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
1836 const char *name, int name_len,
1837 u64 *who_ino, u64 *who_gen, u64 *who_mode)
1839 int ret = 0;
1840 u64 gen;
1841 u64 other_inode = 0;
1842 u8 other_type = 0;
1844 if (!sctx->parent_root)
1845 goto out;
1847 ret = is_inode_existent(sctx, dir, dir_gen);
1848 if (ret <= 0)
1849 goto out;
1852 * If we have a parent root we need to verify that the parent dir was
1853 * not deleted and then re-created, if it was then we have no overwrite
1854 * and we can just unlink this entry.
1856 if (sctx->parent_root && dir != BTRFS_FIRST_FREE_OBJECTID) {
1857 ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
1858 NULL, NULL, NULL);
1859 if (ret < 0 && ret != -ENOENT)
1860 goto out;
1861 if (ret) {
1862 ret = 0;
1863 goto out;
1865 if (gen != dir_gen)
1866 goto out;
1869 ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
1870 &other_inode, &other_type);
1871 if (ret < 0 && ret != -ENOENT)
1872 goto out;
1873 if (ret) {
1874 ret = 0;
1875 goto out;
1879 * Check if the overwritten ref was already processed. If yes, the ref
1880 * was already unlinked/moved, so we can safely assume that we will not
1881 * overwrite anything at this point in time.
1883 if (other_inode > sctx->send_progress ||
1884 is_waiting_for_move(sctx, other_inode)) {
1885 ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1886 who_gen, who_mode, NULL, NULL, NULL);
1887 if (ret < 0)
1888 goto out;
1890 ret = 1;
1891 *who_ino = other_inode;
1892 } else {
1893 ret = 0;
1896 out:
1897 return ret;
1901 * Checks if the ref was overwritten by an already processed inode. This is
1902 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
1903 * thus the orphan name needs be used.
1904 * process_recorded_refs also uses it to avoid unlinking of refs that were
1905 * overwritten.
1907 static int did_overwrite_ref(struct send_ctx *sctx,
1908 u64 dir, u64 dir_gen,
1909 u64 ino, u64 ino_gen,
1910 const char *name, int name_len)
1912 int ret = 0;
1913 u64 gen;
1914 u64 ow_inode;
1915 u8 other_type;
1917 if (!sctx->parent_root)
1918 goto out;
1920 ret = is_inode_existent(sctx, dir, dir_gen);
1921 if (ret <= 0)
1922 goto out;
1924 if (dir != BTRFS_FIRST_FREE_OBJECTID) {
1925 ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL,
1926 NULL, NULL, NULL);
1927 if (ret < 0 && ret != -ENOENT)
1928 goto out;
1929 if (ret) {
1930 ret = 0;
1931 goto out;
1933 if (gen != dir_gen)
1934 goto out;
1937 /* check if the ref was overwritten by another ref */
1938 ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
1939 &ow_inode, &other_type);
1940 if (ret < 0 && ret != -ENOENT)
1941 goto out;
1942 if (ret) {
1943 /* was never and will never be overwritten */
1944 ret = 0;
1945 goto out;
1948 ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1949 NULL, NULL);
1950 if (ret < 0)
1951 goto out;
1953 if (ow_inode == ino && gen == ino_gen) {
1954 ret = 0;
1955 goto out;
1959 * We know that it is or will be overwritten. Check this now.
1960 * The current inode being processed might have been the one that caused
1961 * inode 'ino' to be orphanized, therefore check if ow_inode matches
1962 * the current inode being processed.
1964 if ((ow_inode < sctx->send_progress) ||
1965 (ino != sctx->cur_ino && ow_inode == sctx->cur_ino &&
1966 gen == sctx->cur_inode_gen))
1967 ret = 1;
1968 else
1969 ret = 0;
1971 out:
1972 return ret;
1976 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
1977 * that got overwritten. This is used by process_recorded_refs to determine
1978 * if it has to use the path as returned by get_cur_path or the orphan name.
1980 static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
1982 int ret = 0;
1983 struct fs_path *name = NULL;
1984 u64 dir;
1985 u64 dir_gen;
1987 if (!sctx->parent_root)
1988 goto out;
1990 name = fs_path_alloc();
1991 if (!name)
1992 return -ENOMEM;
1994 ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
1995 if (ret < 0)
1996 goto out;
1998 ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
1999 name->start, fs_path_len(name));
2001 out:
2002 fs_path_free(name);
2003 return ret;
2007 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
2008 * so we need to do some special handling in case we have clashes. This function
2009 * takes care of this with the help of name_cache_entry::radix_list.
2010 * In case of error, nce is kfreed.
2012 static int name_cache_insert(struct send_ctx *sctx,
2013 struct name_cache_entry *nce)
2015 int ret = 0;
2016 struct list_head *nce_head;
2018 nce_head = radix_tree_lookup(&sctx->name_cache,
2019 (unsigned long)nce->ino);
2020 if (!nce_head) {
2021 nce_head = kmalloc(sizeof(*nce_head), GFP_KERNEL);
2022 if (!nce_head) {
2023 kfree(nce);
2024 return -ENOMEM;
2026 INIT_LIST_HEAD(nce_head);
2028 ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
2029 if (ret < 0) {
2030 kfree(nce_head);
2031 kfree(nce);
2032 return ret;
2035 list_add_tail(&nce->radix_list, nce_head);
2036 list_add_tail(&nce->list, &sctx->name_cache_list);
2037 sctx->name_cache_size++;
2039 return ret;
2042 static void name_cache_delete(struct send_ctx *sctx,
2043 struct name_cache_entry *nce)
2045 struct list_head *nce_head;
2047 nce_head = radix_tree_lookup(&sctx->name_cache,
2048 (unsigned long)nce->ino);
2049 if (!nce_head) {
2050 btrfs_err(sctx->send_root->fs_info,
2051 "name_cache_delete lookup failed ino %llu cache size %d, leaking memory",
2052 nce->ino, sctx->name_cache_size);
2055 list_del(&nce->radix_list);
2056 list_del(&nce->list);
2057 sctx->name_cache_size--;
2060 * We may not get to the final release of nce_head if the lookup fails
2062 if (nce_head && list_empty(nce_head)) {
2063 radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
2064 kfree(nce_head);
2068 static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
2069 u64 ino, u64 gen)
2071 struct list_head *nce_head;
2072 struct name_cache_entry *cur;
2074 nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
2075 if (!nce_head)
2076 return NULL;
2078 list_for_each_entry(cur, nce_head, radix_list) {
2079 if (cur->ino == ino && cur->gen == gen)
2080 return cur;
2082 return NULL;
2086 * Removes the entry from the list and adds it back to the end. This marks the
2087 * entry as recently used so that name_cache_clean_unused does not remove it.
2089 static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
2091 list_del(&nce->list);
2092 list_add_tail(&nce->list, &sctx->name_cache_list);
2096 * Remove some entries from the beginning of name_cache_list.
2098 static void name_cache_clean_unused(struct send_ctx *sctx)
2100 struct name_cache_entry *nce;
2102 if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
2103 return;
2105 while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
2106 nce = list_entry(sctx->name_cache_list.next,
2107 struct name_cache_entry, list);
2108 name_cache_delete(sctx, nce);
2109 kfree(nce);
2113 static void name_cache_free(struct send_ctx *sctx)
2115 struct name_cache_entry *nce;
2117 while (!list_empty(&sctx->name_cache_list)) {
2118 nce = list_entry(sctx->name_cache_list.next,
2119 struct name_cache_entry, list);
2120 name_cache_delete(sctx, nce);
2121 kfree(nce);
2126 * Used by get_cur_path for each ref up to the root.
2127 * Returns 0 if it succeeded.
2128 * Returns 1 if the inode is not existent or got overwritten. In that case, the
2129 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
2130 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
2131 * Returns <0 in case of error.
2133 static int __get_cur_name_and_parent(struct send_ctx *sctx,
2134 u64 ino, u64 gen,
2135 u64 *parent_ino,
2136 u64 *parent_gen,
2137 struct fs_path *dest)
2139 int ret;
2140 int nce_ret;
2141 struct name_cache_entry *nce = NULL;
2144 * First check if we already did a call to this function with the same
2145 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
2146 * return the cached result.
2148 nce = name_cache_search(sctx, ino, gen);
2149 if (nce) {
2150 if (ino < sctx->send_progress && nce->need_later_update) {
2151 name_cache_delete(sctx, nce);
2152 kfree(nce);
2153 nce = NULL;
2154 } else {
2155 name_cache_used(sctx, nce);
2156 *parent_ino = nce->parent_ino;
2157 *parent_gen = nce->parent_gen;
2158 ret = fs_path_add(dest, nce->name, nce->name_len);
2159 if (ret < 0)
2160 goto out;
2161 ret = nce->ret;
2162 goto out;
2167 * If the inode is not existent yet, add the orphan name and return 1.
2168 * This should only happen for the parent dir that we determine in
2169 * __record_new_ref
2171 ret = is_inode_existent(sctx, ino, gen);
2172 if (ret < 0)
2173 goto out;
2175 if (!ret) {
2176 ret = gen_unique_name(sctx, ino, gen, dest);
2177 if (ret < 0)
2178 goto out;
2179 ret = 1;
2180 goto out_cache;
2184 * Depending on whether the inode was already processed or not, use
2185 * send_root or parent_root for ref lookup.
2187 if (ino < sctx->send_progress)
2188 ret = get_first_ref(sctx->send_root, ino,
2189 parent_ino, parent_gen, dest);
2190 else
2191 ret = get_first_ref(sctx->parent_root, ino,
2192 parent_ino, parent_gen, dest);
2193 if (ret < 0)
2194 goto out;
2197 * Check if the ref was overwritten by an inode's ref that was processed
2198 * earlier. If yes, treat as orphan and return 1.
2200 ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
2201 dest->start, dest->end - dest->start);
2202 if (ret < 0)
2203 goto out;
2204 if (ret) {
2205 fs_path_reset(dest);
2206 ret = gen_unique_name(sctx, ino, gen, dest);
2207 if (ret < 0)
2208 goto out;
2209 ret = 1;
2212 out_cache:
2214 * Store the result of the lookup in the name cache.
2216 nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_KERNEL);
2217 if (!nce) {
2218 ret = -ENOMEM;
2219 goto out;
2222 nce->ino = ino;
2223 nce->gen = gen;
2224 nce->parent_ino = *parent_ino;
2225 nce->parent_gen = *parent_gen;
2226 nce->name_len = fs_path_len(dest);
2227 nce->ret = ret;
2228 strcpy(nce->name, dest->start);
2230 if (ino < sctx->send_progress)
2231 nce->need_later_update = 0;
2232 else
2233 nce->need_later_update = 1;
2235 nce_ret = name_cache_insert(sctx, nce);
2236 if (nce_ret < 0)
2237 ret = nce_ret;
2238 name_cache_clean_unused(sctx);
2240 out:
2241 return ret;
2245 * Magic happens here. This function returns the first ref to an inode as it
2246 * would look like while receiving the stream at this point in time.
2247 * We walk the path up to the root. For every inode in between, we check if it
2248 * was already processed/sent. If yes, we continue with the parent as found
2249 * in send_root. If not, we continue with the parent as found in parent_root.
2250 * If we encounter an inode that was deleted at this point in time, we use the
2251 * inodes "orphan" name instead of the real name and stop. Same with new inodes
2252 * that were not created yet and overwritten inodes/refs.
2254 * When do we have have orphan inodes:
2255 * 1. When an inode is freshly created and thus no valid refs are available yet
2256 * 2. When a directory lost all it's refs (deleted) but still has dir items
2257 * inside which were not processed yet (pending for move/delete). If anyone
2258 * tried to get the path to the dir items, it would get a path inside that
2259 * orphan directory.
2260 * 3. When an inode is moved around or gets new links, it may overwrite the ref
2261 * of an unprocessed inode. If in that case the first ref would be
2262 * overwritten, the overwritten inode gets "orphanized". Later when we
2263 * process this overwritten inode, it is restored at a new place by moving
2264 * the orphan inode.
2266 * sctx->send_progress tells this function at which point in time receiving
2267 * would be.
2269 static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
2270 struct fs_path *dest)
2272 int ret = 0;
2273 struct fs_path *name = NULL;
2274 u64 parent_inode = 0;
2275 u64 parent_gen = 0;
2276 int stop = 0;
2278 name = fs_path_alloc();
2279 if (!name) {
2280 ret = -ENOMEM;
2281 goto out;
2284 dest->reversed = 1;
2285 fs_path_reset(dest);
2287 while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
2288 struct waiting_dir_move *wdm;
2290 fs_path_reset(name);
2292 if (is_waiting_for_rm(sctx, ino)) {
2293 ret = gen_unique_name(sctx, ino, gen, name);
2294 if (ret < 0)
2295 goto out;
2296 ret = fs_path_add_path(dest, name);
2297 break;
2300 wdm = get_waiting_dir_move(sctx, ino);
2301 if (wdm && wdm->orphanized) {
2302 ret = gen_unique_name(sctx, ino, gen, name);
2303 stop = 1;
2304 } else if (wdm) {
2305 ret = get_first_ref(sctx->parent_root, ino,
2306 &parent_inode, &parent_gen, name);
2307 } else {
2308 ret = __get_cur_name_and_parent(sctx, ino, gen,
2309 &parent_inode,
2310 &parent_gen, name);
2311 if (ret)
2312 stop = 1;
2315 if (ret < 0)
2316 goto out;
2318 ret = fs_path_add_path(dest, name);
2319 if (ret < 0)
2320 goto out;
2322 ino = parent_inode;
2323 gen = parent_gen;
2326 out:
2327 fs_path_free(name);
2328 if (!ret)
2329 fs_path_unreverse(dest);
2330 return ret;
2334 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2336 static int send_subvol_begin(struct send_ctx *sctx)
2338 int ret;
2339 struct btrfs_root *send_root = sctx->send_root;
2340 struct btrfs_root *parent_root = sctx->parent_root;
2341 struct btrfs_path *path;
2342 struct btrfs_key key;
2343 struct btrfs_root_ref *ref;
2344 struct extent_buffer *leaf;
2345 char *name = NULL;
2346 int namelen;
2348 path = btrfs_alloc_path();
2349 if (!path)
2350 return -ENOMEM;
2352 name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_KERNEL);
2353 if (!name) {
2354 btrfs_free_path(path);
2355 return -ENOMEM;
2358 key.objectid = send_root->objectid;
2359 key.type = BTRFS_ROOT_BACKREF_KEY;
2360 key.offset = 0;
2362 ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
2363 &key, path, 1, 0);
2364 if (ret < 0)
2365 goto out;
2366 if (ret) {
2367 ret = -ENOENT;
2368 goto out;
2371 leaf = path->nodes[0];
2372 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2373 if (key.type != BTRFS_ROOT_BACKREF_KEY ||
2374 key.objectid != send_root->objectid) {
2375 ret = -ENOENT;
2376 goto out;
2378 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
2379 namelen = btrfs_root_ref_name_len(leaf, ref);
2380 read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
2381 btrfs_release_path(path);
2383 if (parent_root) {
2384 ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
2385 if (ret < 0)
2386 goto out;
2387 } else {
2388 ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
2389 if (ret < 0)
2390 goto out;
2393 TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
2395 if (!btrfs_is_empty_uuid(sctx->send_root->root_item.received_uuid))
2396 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2397 sctx->send_root->root_item.received_uuid);
2398 else
2399 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2400 sctx->send_root->root_item.uuid);
2402 TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2403 le64_to_cpu(sctx->send_root->root_item.ctransid));
2404 if (parent_root) {
2405 if (!btrfs_is_empty_uuid(parent_root->root_item.received_uuid))
2406 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2407 parent_root->root_item.received_uuid);
2408 else
2409 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2410 parent_root->root_item.uuid);
2411 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2412 le64_to_cpu(sctx->parent_root->root_item.ctransid));
2415 ret = send_cmd(sctx);
2417 tlv_put_failure:
2418 out:
2419 btrfs_free_path(path);
2420 kfree(name);
2421 return ret;
2424 static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
2426 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2427 int ret = 0;
2428 struct fs_path *p;
2430 btrfs_debug(fs_info, "send_truncate %llu size=%llu", ino, size);
2432 p = fs_path_alloc();
2433 if (!p)
2434 return -ENOMEM;
2436 ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
2437 if (ret < 0)
2438 goto out;
2440 ret = get_cur_path(sctx, ino, gen, p);
2441 if (ret < 0)
2442 goto out;
2443 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2444 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
2446 ret = send_cmd(sctx);
2448 tlv_put_failure:
2449 out:
2450 fs_path_free(p);
2451 return ret;
2454 static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
2456 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2457 int ret = 0;
2458 struct fs_path *p;
2460 btrfs_debug(fs_info, "send_chmod %llu mode=%llu", ino, mode);
2462 p = fs_path_alloc();
2463 if (!p)
2464 return -ENOMEM;
2466 ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
2467 if (ret < 0)
2468 goto out;
2470 ret = get_cur_path(sctx, ino, gen, p);
2471 if (ret < 0)
2472 goto out;
2473 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2474 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
2476 ret = send_cmd(sctx);
2478 tlv_put_failure:
2479 out:
2480 fs_path_free(p);
2481 return ret;
2484 static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
2486 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2487 int ret = 0;
2488 struct fs_path *p;
2490 btrfs_debug(fs_info, "send_chown %llu uid=%llu, gid=%llu",
2491 ino, uid, gid);
2493 p = fs_path_alloc();
2494 if (!p)
2495 return -ENOMEM;
2497 ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
2498 if (ret < 0)
2499 goto out;
2501 ret = get_cur_path(sctx, ino, gen, p);
2502 if (ret < 0)
2503 goto out;
2504 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2505 TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
2506 TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
2508 ret = send_cmd(sctx);
2510 tlv_put_failure:
2511 out:
2512 fs_path_free(p);
2513 return ret;
2516 static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
2518 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2519 int ret = 0;
2520 struct fs_path *p = NULL;
2521 struct btrfs_inode_item *ii;
2522 struct btrfs_path *path = NULL;
2523 struct extent_buffer *eb;
2524 struct btrfs_key key;
2525 int slot;
2527 btrfs_debug(fs_info, "send_utimes %llu", ino);
2529 p = fs_path_alloc();
2530 if (!p)
2531 return -ENOMEM;
2533 path = alloc_path_for_send();
2534 if (!path) {
2535 ret = -ENOMEM;
2536 goto out;
2539 key.objectid = ino;
2540 key.type = BTRFS_INODE_ITEM_KEY;
2541 key.offset = 0;
2542 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2543 if (ret > 0)
2544 ret = -ENOENT;
2545 if (ret < 0)
2546 goto out;
2548 eb = path->nodes[0];
2549 slot = path->slots[0];
2550 ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2552 ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
2553 if (ret < 0)
2554 goto out;
2556 ret = get_cur_path(sctx, ino, gen, p);
2557 if (ret < 0)
2558 goto out;
2559 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2560 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb, &ii->atime);
2561 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb, &ii->mtime);
2562 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb, &ii->ctime);
2563 /* TODO Add otime support when the otime patches get into upstream */
2565 ret = send_cmd(sctx);
2567 tlv_put_failure:
2568 out:
2569 fs_path_free(p);
2570 btrfs_free_path(path);
2571 return ret;
2575 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2576 * a valid path yet because we did not process the refs yet. So, the inode
2577 * is created as orphan.
2579 static int send_create_inode(struct send_ctx *sctx, u64 ino)
2581 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2582 int ret = 0;
2583 struct fs_path *p;
2584 int cmd;
2585 u64 gen;
2586 u64 mode;
2587 u64 rdev;
2589 btrfs_debug(fs_info, "send_create_inode %llu", ino);
2591 p = fs_path_alloc();
2592 if (!p)
2593 return -ENOMEM;
2595 if (ino != sctx->cur_ino) {
2596 ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode,
2597 NULL, NULL, &rdev);
2598 if (ret < 0)
2599 goto out;
2600 } else {
2601 gen = sctx->cur_inode_gen;
2602 mode = sctx->cur_inode_mode;
2603 rdev = sctx->cur_inode_rdev;
2606 if (S_ISREG(mode)) {
2607 cmd = BTRFS_SEND_C_MKFILE;
2608 } else if (S_ISDIR(mode)) {
2609 cmd = BTRFS_SEND_C_MKDIR;
2610 } else if (S_ISLNK(mode)) {
2611 cmd = BTRFS_SEND_C_SYMLINK;
2612 } else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2613 cmd = BTRFS_SEND_C_MKNOD;
2614 } else if (S_ISFIFO(mode)) {
2615 cmd = BTRFS_SEND_C_MKFIFO;
2616 } else if (S_ISSOCK(mode)) {
2617 cmd = BTRFS_SEND_C_MKSOCK;
2618 } else {
2619 btrfs_warn(sctx->send_root->fs_info, "unexpected inode type %o",
2620 (int)(mode & S_IFMT));
2621 ret = -EOPNOTSUPP;
2622 goto out;
2625 ret = begin_cmd(sctx, cmd);
2626 if (ret < 0)
2627 goto out;
2629 ret = gen_unique_name(sctx, ino, gen, p);
2630 if (ret < 0)
2631 goto out;
2633 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2634 TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2636 if (S_ISLNK(mode)) {
2637 fs_path_reset(p);
2638 ret = read_symlink(sctx->send_root, ino, p);
2639 if (ret < 0)
2640 goto out;
2641 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
2642 } else if (S_ISCHR(mode) || S_ISBLK(mode) ||
2643 S_ISFIFO(mode) || S_ISSOCK(mode)) {
2644 TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
2645 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2648 ret = send_cmd(sctx);
2649 if (ret < 0)
2650 goto out;
2653 tlv_put_failure:
2654 out:
2655 fs_path_free(p);
2656 return ret;
2660 * We need some special handling for inodes that get processed before the parent
2661 * directory got created. See process_recorded_refs for details.
2662 * This function does the check if we already created the dir out of order.
2664 static int did_create_dir(struct send_ctx *sctx, u64 dir)
2666 int ret = 0;
2667 struct btrfs_path *path = NULL;
2668 struct btrfs_key key;
2669 struct btrfs_key found_key;
2670 struct btrfs_key di_key;
2671 struct extent_buffer *eb;
2672 struct btrfs_dir_item *di;
2673 int slot;
2675 path = alloc_path_for_send();
2676 if (!path) {
2677 ret = -ENOMEM;
2678 goto out;
2681 key.objectid = dir;
2682 key.type = BTRFS_DIR_INDEX_KEY;
2683 key.offset = 0;
2684 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2685 if (ret < 0)
2686 goto out;
2688 while (1) {
2689 eb = path->nodes[0];
2690 slot = path->slots[0];
2691 if (slot >= btrfs_header_nritems(eb)) {
2692 ret = btrfs_next_leaf(sctx->send_root, path);
2693 if (ret < 0) {
2694 goto out;
2695 } else if (ret > 0) {
2696 ret = 0;
2697 break;
2699 continue;
2702 btrfs_item_key_to_cpu(eb, &found_key, slot);
2703 if (found_key.objectid != key.objectid ||
2704 found_key.type != key.type) {
2705 ret = 0;
2706 goto out;
2709 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2710 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2712 if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
2713 di_key.objectid < sctx->send_progress) {
2714 ret = 1;
2715 goto out;
2718 path->slots[0]++;
2721 out:
2722 btrfs_free_path(path);
2723 return ret;
2727 * Only creates the inode if it is:
2728 * 1. Not a directory
2729 * 2. Or a directory which was not created already due to out of order
2730 * directories. See did_create_dir and process_recorded_refs for details.
2732 static int send_create_inode_if_needed(struct send_ctx *sctx)
2734 int ret;
2736 if (S_ISDIR(sctx->cur_inode_mode)) {
2737 ret = did_create_dir(sctx, sctx->cur_ino);
2738 if (ret < 0)
2739 goto out;
2740 if (ret) {
2741 ret = 0;
2742 goto out;
2746 ret = send_create_inode(sctx, sctx->cur_ino);
2747 if (ret < 0)
2748 goto out;
2750 out:
2751 return ret;
2754 struct recorded_ref {
2755 struct list_head list;
2756 char *name;
2757 struct fs_path *full_path;
2758 u64 dir;
2759 u64 dir_gen;
2760 int name_len;
2763 static void set_ref_path(struct recorded_ref *ref, struct fs_path *path)
2765 ref->full_path = path;
2766 ref->name = (char *)kbasename(ref->full_path->start);
2767 ref->name_len = ref->full_path->end - ref->name;
2771 * We need to process new refs before deleted refs, but compare_tree gives us
2772 * everything mixed. So we first record all refs and later process them.
2773 * This function is a helper to record one ref.
2775 static int __record_ref(struct list_head *head, u64 dir,
2776 u64 dir_gen, struct fs_path *path)
2778 struct recorded_ref *ref;
2780 ref = kmalloc(sizeof(*ref), GFP_KERNEL);
2781 if (!ref)
2782 return -ENOMEM;
2784 ref->dir = dir;
2785 ref->dir_gen = dir_gen;
2786 set_ref_path(ref, path);
2787 list_add_tail(&ref->list, head);
2788 return 0;
2791 static int dup_ref(struct recorded_ref *ref, struct list_head *list)
2793 struct recorded_ref *new;
2795 new = kmalloc(sizeof(*ref), GFP_KERNEL);
2796 if (!new)
2797 return -ENOMEM;
2799 new->dir = ref->dir;
2800 new->dir_gen = ref->dir_gen;
2801 new->full_path = NULL;
2802 INIT_LIST_HEAD(&new->list);
2803 list_add_tail(&new->list, list);
2804 return 0;
2807 static void __free_recorded_refs(struct list_head *head)
2809 struct recorded_ref *cur;
2811 while (!list_empty(head)) {
2812 cur = list_entry(head->next, struct recorded_ref, list);
2813 fs_path_free(cur->full_path);
2814 list_del(&cur->list);
2815 kfree(cur);
2819 static void free_recorded_refs(struct send_ctx *sctx)
2821 __free_recorded_refs(&sctx->new_refs);
2822 __free_recorded_refs(&sctx->deleted_refs);
2826 * Renames/moves a file/dir to its orphan name. Used when the first
2827 * ref of an unprocessed inode gets overwritten and for all non empty
2828 * directories.
2830 static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
2831 struct fs_path *path)
2833 int ret;
2834 struct fs_path *orphan;
2836 orphan = fs_path_alloc();
2837 if (!orphan)
2838 return -ENOMEM;
2840 ret = gen_unique_name(sctx, ino, gen, orphan);
2841 if (ret < 0)
2842 goto out;
2844 ret = send_rename(sctx, path, orphan);
2846 out:
2847 fs_path_free(orphan);
2848 return ret;
2851 static struct orphan_dir_info *
2852 add_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2854 struct rb_node **p = &sctx->orphan_dirs.rb_node;
2855 struct rb_node *parent = NULL;
2856 struct orphan_dir_info *entry, *odi;
2858 odi = kmalloc(sizeof(*odi), GFP_KERNEL);
2859 if (!odi)
2860 return ERR_PTR(-ENOMEM);
2861 odi->ino = dir_ino;
2862 odi->gen = 0;
2864 while (*p) {
2865 parent = *p;
2866 entry = rb_entry(parent, struct orphan_dir_info, node);
2867 if (dir_ino < entry->ino) {
2868 p = &(*p)->rb_left;
2869 } else if (dir_ino > entry->ino) {
2870 p = &(*p)->rb_right;
2871 } else {
2872 kfree(odi);
2873 return entry;
2877 rb_link_node(&odi->node, parent, p);
2878 rb_insert_color(&odi->node, &sctx->orphan_dirs);
2879 return odi;
2882 static struct orphan_dir_info *
2883 get_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2885 struct rb_node *n = sctx->orphan_dirs.rb_node;
2886 struct orphan_dir_info *entry;
2888 while (n) {
2889 entry = rb_entry(n, struct orphan_dir_info, node);
2890 if (dir_ino < entry->ino)
2891 n = n->rb_left;
2892 else if (dir_ino > entry->ino)
2893 n = n->rb_right;
2894 else
2895 return entry;
2897 return NULL;
2900 static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino)
2902 struct orphan_dir_info *odi = get_orphan_dir_info(sctx, dir_ino);
2904 return odi != NULL;
2907 static void free_orphan_dir_info(struct send_ctx *sctx,
2908 struct orphan_dir_info *odi)
2910 if (!odi)
2911 return;
2912 rb_erase(&odi->node, &sctx->orphan_dirs);
2913 kfree(odi);
2917 * Returns 1 if a directory can be removed at this point in time.
2918 * We check this by iterating all dir items and checking if the inode behind
2919 * the dir item was already processed.
2921 static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
2922 u64 send_progress)
2924 int ret = 0;
2925 struct btrfs_root *root = sctx->parent_root;
2926 struct btrfs_path *path;
2927 struct btrfs_key key;
2928 struct btrfs_key found_key;
2929 struct btrfs_key loc;
2930 struct btrfs_dir_item *di;
2933 * Don't try to rmdir the top/root subvolume dir.
2935 if (dir == BTRFS_FIRST_FREE_OBJECTID)
2936 return 0;
2938 path = alloc_path_for_send();
2939 if (!path)
2940 return -ENOMEM;
2942 key.objectid = dir;
2943 key.type = BTRFS_DIR_INDEX_KEY;
2944 key.offset = 0;
2945 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2946 if (ret < 0)
2947 goto out;
2949 while (1) {
2950 struct waiting_dir_move *dm;
2952 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2953 ret = btrfs_next_leaf(root, path);
2954 if (ret < 0)
2955 goto out;
2956 else if (ret > 0)
2957 break;
2958 continue;
2960 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2961 path->slots[0]);
2962 if (found_key.objectid != key.objectid ||
2963 found_key.type != key.type)
2964 break;
2966 di = btrfs_item_ptr(path->nodes[0], path->slots[0],
2967 struct btrfs_dir_item);
2968 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
2970 dm = get_waiting_dir_move(sctx, loc.objectid);
2971 if (dm) {
2972 struct orphan_dir_info *odi;
2974 odi = add_orphan_dir_info(sctx, dir);
2975 if (IS_ERR(odi)) {
2976 ret = PTR_ERR(odi);
2977 goto out;
2979 odi->gen = dir_gen;
2980 dm->rmdir_ino = dir;
2981 ret = 0;
2982 goto out;
2985 if (loc.objectid > send_progress) {
2986 struct orphan_dir_info *odi;
2988 odi = get_orphan_dir_info(sctx, dir);
2989 free_orphan_dir_info(sctx, odi);
2990 ret = 0;
2991 goto out;
2994 path->slots[0]++;
2997 ret = 1;
2999 out:
3000 btrfs_free_path(path);
3001 return ret;
3004 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
3006 struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino);
3008 return entry != NULL;
3011 static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, bool orphanized)
3013 struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
3014 struct rb_node *parent = NULL;
3015 struct waiting_dir_move *entry, *dm;
3017 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
3018 if (!dm)
3019 return -ENOMEM;
3020 dm->ino = ino;
3021 dm->rmdir_ino = 0;
3022 dm->orphanized = orphanized;
3024 while (*p) {
3025 parent = *p;
3026 entry = rb_entry(parent, struct waiting_dir_move, node);
3027 if (ino < entry->ino) {
3028 p = &(*p)->rb_left;
3029 } else if (ino > entry->ino) {
3030 p = &(*p)->rb_right;
3031 } else {
3032 kfree(dm);
3033 return -EEXIST;
3037 rb_link_node(&dm->node, parent, p);
3038 rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
3039 return 0;
3042 static struct waiting_dir_move *
3043 get_waiting_dir_move(struct send_ctx *sctx, u64 ino)
3045 struct rb_node *n = sctx->waiting_dir_moves.rb_node;
3046 struct waiting_dir_move *entry;
3048 while (n) {
3049 entry = rb_entry(n, struct waiting_dir_move, node);
3050 if (ino < entry->ino)
3051 n = n->rb_left;
3052 else if (ino > entry->ino)
3053 n = n->rb_right;
3054 else
3055 return entry;
3057 return NULL;
3060 static void free_waiting_dir_move(struct send_ctx *sctx,
3061 struct waiting_dir_move *dm)
3063 if (!dm)
3064 return;
3065 rb_erase(&dm->node, &sctx->waiting_dir_moves);
3066 kfree(dm);
3069 static int add_pending_dir_move(struct send_ctx *sctx,
3070 u64 ino,
3071 u64 ino_gen,
3072 u64 parent_ino,
3073 struct list_head *new_refs,
3074 struct list_head *deleted_refs,
3075 const bool is_orphan)
3077 struct rb_node **p = &sctx->pending_dir_moves.rb_node;
3078 struct rb_node *parent = NULL;
3079 struct pending_dir_move *entry = NULL, *pm;
3080 struct recorded_ref *cur;
3081 int exists = 0;
3082 int ret;
3084 pm = kmalloc(sizeof(*pm), GFP_KERNEL);
3085 if (!pm)
3086 return -ENOMEM;
3087 pm->parent_ino = parent_ino;
3088 pm->ino = ino;
3089 pm->gen = ino_gen;
3090 INIT_LIST_HEAD(&pm->list);
3091 INIT_LIST_HEAD(&pm->update_refs);
3092 RB_CLEAR_NODE(&pm->node);
3094 while (*p) {
3095 parent = *p;
3096 entry = rb_entry(parent, struct pending_dir_move, node);
3097 if (parent_ino < entry->parent_ino) {
3098 p = &(*p)->rb_left;
3099 } else if (parent_ino > entry->parent_ino) {
3100 p = &(*p)->rb_right;
3101 } else {
3102 exists = 1;
3103 break;
3107 list_for_each_entry(cur, deleted_refs, list) {
3108 ret = dup_ref(cur, &pm->update_refs);
3109 if (ret < 0)
3110 goto out;
3112 list_for_each_entry(cur, new_refs, list) {
3113 ret = dup_ref(cur, &pm->update_refs);
3114 if (ret < 0)
3115 goto out;
3118 ret = add_waiting_dir_move(sctx, pm->ino, is_orphan);
3119 if (ret)
3120 goto out;
3122 if (exists) {
3123 list_add_tail(&pm->list, &entry->list);
3124 } else {
3125 rb_link_node(&pm->node, parent, p);
3126 rb_insert_color(&pm->node, &sctx->pending_dir_moves);
3128 ret = 0;
3129 out:
3130 if (ret) {
3131 __free_recorded_refs(&pm->update_refs);
3132 kfree(pm);
3134 return ret;
3137 static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
3138 u64 parent_ino)
3140 struct rb_node *n = sctx->pending_dir_moves.rb_node;
3141 struct pending_dir_move *entry;
3143 while (n) {
3144 entry = rb_entry(n, struct pending_dir_move, node);
3145 if (parent_ino < entry->parent_ino)
3146 n = n->rb_left;
3147 else if (parent_ino > entry->parent_ino)
3148 n = n->rb_right;
3149 else
3150 return entry;
3152 return NULL;
3155 static int path_loop(struct send_ctx *sctx, struct fs_path *name,
3156 u64 ino, u64 gen, u64 *ancestor_ino)
3158 int ret = 0;
3159 u64 parent_inode = 0;
3160 u64 parent_gen = 0;
3161 u64 start_ino = ino;
3163 *ancestor_ino = 0;
3164 while (ino != BTRFS_FIRST_FREE_OBJECTID) {
3165 fs_path_reset(name);
3167 if (is_waiting_for_rm(sctx, ino))
3168 break;
3169 if (is_waiting_for_move(sctx, ino)) {
3170 if (*ancestor_ino == 0)
3171 *ancestor_ino = ino;
3172 ret = get_first_ref(sctx->parent_root, ino,
3173 &parent_inode, &parent_gen, name);
3174 } else {
3175 ret = __get_cur_name_and_parent(sctx, ino, gen,
3176 &parent_inode,
3177 &parent_gen, name);
3178 if (ret > 0) {
3179 ret = 0;
3180 break;
3183 if (ret < 0)
3184 break;
3185 if (parent_inode == start_ino) {
3186 ret = 1;
3187 if (*ancestor_ino == 0)
3188 *ancestor_ino = ino;
3189 break;
3191 ino = parent_inode;
3192 gen = parent_gen;
3194 return ret;
3197 static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
3199 struct fs_path *from_path = NULL;
3200 struct fs_path *to_path = NULL;
3201 struct fs_path *name = NULL;
3202 u64 orig_progress = sctx->send_progress;
3203 struct recorded_ref *cur;
3204 u64 parent_ino, parent_gen;
3205 struct waiting_dir_move *dm = NULL;
3206 u64 rmdir_ino = 0;
3207 u64 ancestor;
3208 bool is_orphan;
3209 int ret;
3211 name = fs_path_alloc();
3212 from_path = fs_path_alloc();
3213 if (!name || !from_path) {
3214 ret = -ENOMEM;
3215 goto out;
3218 dm = get_waiting_dir_move(sctx, pm->ino);
3219 ASSERT(dm);
3220 rmdir_ino = dm->rmdir_ino;
3221 is_orphan = dm->orphanized;
3222 free_waiting_dir_move(sctx, dm);
3224 if (is_orphan) {
3225 ret = gen_unique_name(sctx, pm->ino,
3226 pm->gen, from_path);
3227 } else {
3228 ret = get_first_ref(sctx->parent_root, pm->ino,
3229 &parent_ino, &parent_gen, name);
3230 if (ret < 0)
3231 goto out;
3232 ret = get_cur_path(sctx, parent_ino, parent_gen,
3233 from_path);
3234 if (ret < 0)
3235 goto out;
3236 ret = fs_path_add_path(from_path, name);
3238 if (ret < 0)
3239 goto out;
3241 sctx->send_progress = sctx->cur_ino + 1;
3242 ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor);
3243 if (ret < 0)
3244 goto out;
3245 if (ret) {
3246 LIST_HEAD(deleted_refs);
3247 ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID);
3248 ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor,
3249 &pm->update_refs, &deleted_refs,
3250 is_orphan);
3251 if (ret < 0)
3252 goto out;
3253 if (rmdir_ino) {
3254 dm = get_waiting_dir_move(sctx, pm->ino);
3255 ASSERT(dm);
3256 dm->rmdir_ino = rmdir_ino;
3258 goto out;
3260 fs_path_reset(name);
3261 to_path = name;
3262 name = NULL;
3263 ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
3264 if (ret < 0)
3265 goto out;
3267 ret = send_rename(sctx, from_path, to_path);
3268 if (ret < 0)
3269 goto out;
3271 if (rmdir_ino) {
3272 struct orphan_dir_info *odi;
3274 odi = get_orphan_dir_info(sctx, rmdir_ino);
3275 if (!odi) {
3276 /* already deleted */
3277 goto finish;
3279 ret = can_rmdir(sctx, rmdir_ino, odi->gen, sctx->cur_ino);
3280 if (ret < 0)
3281 goto out;
3282 if (!ret)
3283 goto finish;
3285 name = fs_path_alloc();
3286 if (!name) {
3287 ret = -ENOMEM;
3288 goto out;
3290 ret = get_cur_path(sctx, rmdir_ino, odi->gen, name);
3291 if (ret < 0)
3292 goto out;
3293 ret = send_rmdir(sctx, name);
3294 if (ret < 0)
3295 goto out;
3296 free_orphan_dir_info(sctx, odi);
3299 finish:
3300 ret = send_utimes(sctx, pm->ino, pm->gen);
3301 if (ret < 0)
3302 goto out;
3305 * After rename/move, need to update the utimes of both new parent(s)
3306 * and old parent(s).
3308 list_for_each_entry(cur, &pm->update_refs, list) {
3310 * The parent inode might have been deleted in the send snapshot
3312 ret = get_inode_info(sctx->send_root, cur->dir, NULL,
3313 NULL, NULL, NULL, NULL, NULL);
3314 if (ret == -ENOENT) {
3315 ret = 0;
3316 continue;
3318 if (ret < 0)
3319 goto out;
3321 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3322 if (ret < 0)
3323 goto out;
3326 out:
3327 fs_path_free(name);
3328 fs_path_free(from_path);
3329 fs_path_free(to_path);
3330 sctx->send_progress = orig_progress;
3332 return ret;
3335 static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
3337 if (!list_empty(&m->list))
3338 list_del(&m->list);
3339 if (!RB_EMPTY_NODE(&m->node))
3340 rb_erase(&m->node, &sctx->pending_dir_moves);
3341 __free_recorded_refs(&m->update_refs);
3342 kfree(m);
3345 static void tail_append_pending_moves(struct pending_dir_move *moves,
3346 struct list_head *stack)
3348 if (list_empty(&moves->list)) {
3349 list_add_tail(&moves->list, stack);
3350 } else {
3351 LIST_HEAD(list);
3352 list_splice_init(&moves->list, &list);
3353 list_add_tail(&moves->list, stack);
3354 list_splice_tail(&list, stack);
3358 static int apply_children_dir_moves(struct send_ctx *sctx)
3360 struct pending_dir_move *pm;
3361 struct list_head stack;
3362 u64 parent_ino = sctx->cur_ino;
3363 int ret = 0;
3365 pm = get_pending_dir_moves(sctx, parent_ino);
3366 if (!pm)
3367 return 0;
3369 INIT_LIST_HEAD(&stack);
3370 tail_append_pending_moves(pm, &stack);
3372 while (!list_empty(&stack)) {
3373 pm = list_first_entry(&stack, struct pending_dir_move, list);
3374 parent_ino = pm->ino;
3375 ret = apply_dir_move(sctx, pm);
3376 free_pending_move(sctx, pm);
3377 if (ret)
3378 goto out;
3379 pm = get_pending_dir_moves(sctx, parent_ino);
3380 if (pm)
3381 tail_append_pending_moves(pm, &stack);
3383 return 0;
3385 out:
3386 while (!list_empty(&stack)) {
3387 pm = list_first_entry(&stack, struct pending_dir_move, list);
3388 free_pending_move(sctx, pm);
3390 return ret;
3394 * We might need to delay a directory rename even when no ancestor directory
3395 * (in the send root) with a higher inode number than ours (sctx->cur_ino) was
3396 * renamed. This happens when we rename a directory to the old name (the name
3397 * in the parent root) of some other unrelated directory that got its rename
3398 * delayed due to some ancestor with higher number that got renamed.
3400 * Example:
3402 * Parent snapshot:
3403 * . (ino 256)
3404 * |---- a/ (ino 257)
3405 * | |---- file (ino 260)
3407 * |---- b/ (ino 258)
3408 * |---- c/ (ino 259)
3410 * Send snapshot:
3411 * . (ino 256)
3412 * |---- a/ (ino 258)
3413 * |---- x/ (ino 259)
3414 * |---- y/ (ino 257)
3415 * |----- file (ino 260)
3417 * Here we can not rename 258 from 'b' to 'a' without the rename of inode 257
3418 * from 'a' to 'x/y' happening first, which in turn depends on the rename of
3419 * inode 259 from 'c' to 'x'. So the order of rename commands the send stream
3420 * must issue is:
3422 * 1 - rename 259 from 'c' to 'x'
3423 * 2 - rename 257 from 'a' to 'x/y'
3424 * 3 - rename 258 from 'b' to 'a'
3426 * Returns 1 if the rename of sctx->cur_ino needs to be delayed, 0 if it can
3427 * be done right away and < 0 on error.
3429 static int wait_for_dest_dir_move(struct send_ctx *sctx,
3430 struct recorded_ref *parent_ref,
3431 const bool is_orphan)
3433 struct btrfs_fs_info *fs_info = sctx->parent_root->fs_info;
3434 struct btrfs_path *path;
3435 struct btrfs_key key;
3436 struct btrfs_key di_key;
3437 struct btrfs_dir_item *di;
3438 u64 left_gen;
3439 u64 right_gen;
3440 int ret = 0;
3441 struct waiting_dir_move *wdm;
3443 if (RB_EMPTY_ROOT(&sctx->waiting_dir_moves))
3444 return 0;
3446 path = alloc_path_for_send();
3447 if (!path)
3448 return -ENOMEM;
3450 key.objectid = parent_ref->dir;
3451 key.type = BTRFS_DIR_ITEM_KEY;
3452 key.offset = btrfs_name_hash(parent_ref->name, parent_ref->name_len);
3454 ret = btrfs_search_slot(NULL, sctx->parent_root, &key, path, 0, 0);
3455 if (ret < 0) {
3456 goto out;
3457 } else if (ret > 0) {
3458 ret = 0;
3459 goto out;
3462 di = btrfs_match_dir_item_name(fs_info, path, parent_ref->name,
3463 parent_ref->name_len);
3464 if (!di) {
3465 ret = 0;
3466 goto out;
3469 * di_key.objectid has the number of the inode that has a dentry in the
3470 * parent directory with the same name that sctx->cur_ino is being
3471 * renamed to. We need to check if that inode is in the send root as
3472 * well and if it is currently marked as an inode with a pending rename,
3473 * if it is, we need to delay the rename of sctx->cur_ino as well, so
3474 * that it happens after that other inode is renamed.
3476 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &di_key);
3477 if (di_key.type != BTRFS_INODE_ITEM_KEY) {
3478 ret = 0;
3479 goto out;
3482 ret = get_inode_info(sctx->parent_root, di_key.objectid, NULL,
3483 &left_gen, NULL, NULL, NULL, NULL);
3484 if (ret < 0)
3485 goto out;
3486 ret = get_inode_info(sctx->send_root, di_key.objectid, NULL,
3487 &right_gen, NULL, NULL, NULL, NULL);
3488 if (ret < 0) {
3489 if (ret == -ENOENT)
3490 ret = 0;
3491 goto out;
3494 /* Different inode, no need to delay the rename of sctx->cur_ino */
3495 if (right_gen != left_gen) {
3496 ret = 0;
3497 goto out;
3500 wdm = get_waiting_dir_move(sctx, di_key.objectid);
3501 if (wdm && !wdm->orphanized) {
3502 ret = add_pending_dir_move(sctx,
3503 sctx->cur_ino,
3504 sctx->cur_inode_gen,
3505 di_key.objectid,
3506 &sctx->new_refs,
3507 &sctx->deleted_refs,
3508 is_orphan);
3509 if (!ret)
3510 ret = 1;
3512 out:
3513 btrfs_free_path(path);
3514 return ret;
3518 * Check if inode ino2, or any of its ancestors, is inode ino1.
3519 * Return 1 if true, 0 if false and < 0 on error.
3521 static int check_ino_in_path(struct btrfs_root *root,
3522 const u64 ino1,
3523 const u64 ino1_gen,
3524 const u64 ino2,
3525 const u64 ino2_gen,
3526 struct fs_path *fs_path)
3528 u64 ino = ino2;
3530 if (ino1 == ino2)
3531 return ino1_gen == ino2_gen;
3533 while (ino > BTRFS_FIRST_FREE_OBJECTID) {
3534 u64 parent;
3535 u64 parent_gen;
3536 int ret;
3538 fs_path_reset(fs_path);
3539 ret = get_first_ref(root, ino, &parent, &parent_gen, fs_path);
3540 if (ret < 0)
3541 return ret;
3542 if (parent == ino1)
3543 return parent_gen == ino1_gen;
3544 ino = parent;
3546 return 0;
3550 * Check if ino ino1 is an ancestor of inode ino2 in the given root for any
3551 * possible path (in case ino2 is not a directory and has multiple hard links).
3552 * Return 1 if true, 0 if false and < 0 on error.
3554 static int is_ancestor(struct btrfs_root *root,
3555 const u64 ino1,
3556 const u64 ino1_gen,
3557 const u64 ino2,
3558 struct fs_path *fs_path)
3560 bool free_fs_path = false;
3561 int ret = 0;
3562 struct btrfs_path *path = NULL;
3563 struct btrfs_key key;
3565 if (!fs_path) {
3566 fs_path = fs_path_alloc();
3567 if (!fs_path)
3568 return -ENOMEM;
3569 free_fs_path = true;
3572 path = alloc_path_for_send();
3573 if (!path) {
3574 ret = -ENOMEM;
3575 goto out;
3578 key.objectid = ino2;
3579 key.type = BTRFS_INODE_REF_KEY;
3580 key.offset = 0;
3582 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3583 if (ret < 0)
3584 goto out;
3586 while (true) {
3587 struct extent_buffer *leaf = path->nodes[0];
3588 int slot = path->slots[0];
3589 u32 cur_offset = 0;
3590 u32 item_size;
3592 if (slot >= btrfs_header_nritems(leaf)) {
3593 ret = btrfs_next_leaf(root, path);
3594 if (ret < 0)
3595 goto out;
3596 if (ret > 0)
3597 break;
3598 continue;
3601 btrfs_item_key_to_cpu(leaf, &key, slot);
3602 if (key.objectid != ino2)
3603 break;
3604 if (key.type != BTRFS_INODE_REF_KEY &&
3605 key.type != BTRFS_INODE_EXTREF_KEY)
3606 break;
3608 item_size = btrfs_item_size_nr(leaf, slot);
3609 while (cur_offset < item_size) {
3610 u64 parent;
3611 u64 parent_gen;
3613 if (key.type == BTRFS_INODE_EXTREF_KEY) {
3614 unsigned long ptr;
3615 struct btrfs_inode_extref *extref;
3617 ptr = btrfs_item_ptr_offset(leaf, slot);
3618 extref = (struct btrfs_inode_extref *)
3619 (ptr + cur_offset);
3620 parent = btrfs_inode_extref_parent(leaf,
3621 extref);
3622 cur_offset += sizeof(*extref);
3623 cur_offset += btrfs_inode_extref_name_len(leaf,
3624 extref);
3625 } else {
3626 parent = key.offset;
3627 cur_offset = item_size;
3630 ret = get_inode_info(root, parent, NULL, &parent_gen,
3631 NULL, NULL, NULL, NULL);
3632 if (ret < 0)
3633 goto out;
3634 ret = check_ino_in_path(root, ino1, ino1_gen,
3635 parent, parent_gen, fs_path);
3636 if (ret)
3637 goto out;
3639 path->slots[0]++;
3641 ret = 0;
3642 out:
3643 btrfs_free_path(path);
3644 if (free_fs_path)
3645 fs_path_free(fs_path);
3646 return ret;
3649 static int wait_for_parent_move(struct send_ctx *sctx,
3650 struct recorded_ref *parent_ref,
3651 const bool is_orphan)
3653 int ret = 0;
3654 u64 ino = parent_ref->dir;
3655 u64 ino_gen = parent_ref->dir_gen;
3656 u64 parent_ino_before, parent_ino_after;
3657 struct fs_path *path_before = NULL;
3658 struct fs_path *path_after = NULL;
3659 int len1, len2;
3661 path_after = fs_path_alloc();
3662 path_before = fs_path_alloc();
3663 if (!path_after || !path_before) {
3664 ret = -ENOMEM;
3665 goto out;
3669 * Our current directory inode may not yet be renamed/moved because some
3670 * ancestor (immediate or not) has to be renamed/moved first. So find if
3671 * such ancestor exists and make sure our own rename/move happens after
3672 * that ancestor is processed to avoid path build infinite loops (done
3673 * at get_cur_path()).
3675 while (ino > BTRFS_FIRST_FREE_OBJECTID) {
3676 u64 parent_ino_after_gen;
3678 if (is_waiting_for_move(sctx, ino)) {
3680 * If the current inode is an ancestor of ino in the
3681 * parent root, we need to delay the rename of the
3682 * current inode, otherwise don't delayed the rename
3683 * because we can end up with a circular dependency
3684 * of renames, resulting in some directories never
3685 * getting the respective rename operations issued in
3686 * the send stream or getting into infinite path build
3687 * loops.
3689 ret = is_ancestor(sctx->parent_root,
3690 sctx->cur_ino, sctx->cur_inode_gen,
3691 ino, path_before);
3692 if (ret)
3693 break;
3696 fs_path_reset(path_before);
3697 fs_path_reset(path_after);
3699 ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3700 &parent_ino_after_gen, path_after);
3701 if (ret < 0)
3702 goto out;
3703 ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
3704 NULL, path_before);
3705 if (ret < 0 && ret != -ENOENT) {
3706 goto out;
3707 } else if (ret == -ENOENT) {
3708 ret = 0;
3709 break;
3712 len1 = fs_path_len(path_before);
3713 len2 = fs_path_len(path_after);
3714 if (ino > sctx->cur_ino &&
3715 (parent_ino_before != parent_ino_after || len1 != len2 ||
3716 memcmp(path_before->start, path_after->start, len1))) {
3717 u64 parent_ino_gen;
3719 ret = get_inode_info(sctx->parent_root, ino, NULL,
3720 &parent_ino_gen, NULL, NULL, NULL,
3721 NULL);
3722 if (ret < 0)
3723 goto out;
3724 if (ino_gen == parent_ino_gen) {
3725 ret = 1;
3726 break;
3729 ino = parent_ino_after;
3730 ino_gen = parent_ino_after_gen;
3733 out:
3734 fs_path_free(path_before);
3735 fs_path_free(path_after);
3737 if (ret == 1) {
3738 ret = add_pending_dir_move(sctx,
3739 sctx->cur_ino,
3740 sctx->cur_inode_gen,
3741 ino,
3742 &sctx->new_refs,
3743 &sctx->deleted_refs,
3744 is_orphan);
3745 if (!ret)
3746 ret = 1;
3749 return ret;
3752 static int update_ref_path(struct send_ctx *sctx, struct recorded_ref *ref)
3754 int ret;
3755 struct fs_path *new_path;
3758 * Our reference's name member points to its full_path member string, so
3759 * we use here a new path.
3761 new_path = fs_path_alloc();
3762 if (!new_path)
3763 return -ENOMEM;
3765 ret = get_cur_path(sctx, ref->dir, ref->dir_gen, new_path);
3766 if (ret < 0) {
3767 fs_path_free(new_path);
3768 return ret;
3770 ret = fs_path_add(new_path, ref->name, ref->name_len);
3771 if (ret < 0) {
3772 fs_path_free(new_path);
3773 return ret;
3776 fs_path_free(ref->full_path);
3777 set_ref_path(ref, new_path);
3779 return 0;
3783 * This does all the move/link/unlink/rmdir magic.
3785 static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
3787 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
3788 int ret = 0;
3789 struct recorded_ref *cur;
3790 struct recorded_ref *cur2;
3791 struct list_head check_dirs;
3792 struct fs_path *valid_path = NULL;
3793 u64 ow_inode = 0;
3794 u64 ow_gen;
3795 u64 ow_mode;
3796 int did_overwrite = 0;
3797 int is_orphan = 0;
3798 u64 last_dir_ino_rm = 0;
3799 bool can_rename = true;
3800 bool orphanized_dir = false;
3801 bool orphanized_ancestor = false;
3803 btrfs_debug(fs_info, "process_recorded_refs %llu", sctx->cur_ino);
3806 * This should never happen as the root dir always has the same ref
3807 * which is always '..'
3809 BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
3810 INIT_LIST_HEAD(&check_dirs);
3812 valid_path = fs_path_alloc();
3813 if (!valid_path) {
3814 ret = -ENOMEM;
3815 goto out;
3819 * First, check if the first ref of the current inode was overwritten
3820 * before. If yes, we know that the current inode was already orphanized
3821 * and thus use the orphan name. If not, we can use get_cur_path to
3822 * get the path of the first ref as it would like while receiving at
3823 * this point in time.
3824 * New inodes are always orphan at the beginning, so force to use the
3825 * orphan name in this case.
3826 * The first ref is stored in valid_path and will be updated if it
3827 * gets moved around.
3829 if (!sctx->cur_inode_new) {
3830 ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
3831 sctx->cur_inode_gen);
3832 if (ret < 0)
3833 goto out;
3834 if (ret)
3835 did_overwrite = 1;
3837 if (sctx->cur_inode_new || did_overwrite) {
3838 ret = gen_unique_name(sctx, sctx->cur_ino,
3839 sctx->cur_inode_gen, valid_path);
3840 if (ret < 0)
3841 goto out;
3842 is_orphan = 1;
3843 } else {
3844 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3845 valid_path);
3846 if (ret < 0)
3847 goto out;
3850 list_for_each_entry(cur, &sctx->new_refs, list) {
3852 * We may have refs where the parent directory does not exist
3853 * yet. This happens if the parent directories inum is higher
3854 * the the current inum. To handle this case, we create the
3855 * parent directory out of order. But we need to check if this
3856 * did already happen before due to other refs in the same dir.
3858 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3859 if (ret < 0)
3860 goto out;
3861 if (ret == inode_state_will_create) {
3862 ret = 0;
3864 * First check if any of the current inodes refs did
3865 * already create the dir.
3867 list_for_each_entry(cur2, &sctx->new_refs, list) {
3868 if (cur == cur2)
3869 break;
3870 if (cur2->dir == cur->dir) {
3871 ret = 1;
3872 break;
3877 * If that did not happen, check if a previous inode
3878 * did already create the dir.
3880 if (!ret)
3881 ret = did_create_dir(sctx, cur->dir);
3882 if (ret < 0)
3883 goto out;
3884 if (!ret) {
3885 ret = send_create_inode(sctx, cur->dir);
3886 if (ret < 0)
3887 goto out;
3892 * Check if this new ref would overwrite the first ref of
3893 * another unprocessed inode. If yes, orphanize the
3894 * overwritten inode. If we find an overwritten ref that is
3895 * not the first ref, simply unlink it.
3897 ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3898 cur->name, cur->name_len,
3899 &ow_inode, &ow_gen, &ow_mode);
3900 if (ret < 0)
3901 goto out;
3902 if (ret) {
3903 ret = is_first_ref(sctx->parent_root,
3904 ow_inode, cur->dir, cur->name,
3905 cur->name_len);
3906 if (ret < 0)
3907 goto out;
3908 if (ret) {
3909 struct name_cache_entry *nce;
3910 struct waiting_dir_move *wdm;
3912 ret = orphanize_inode(sctx, ow_inode, ow_gen,
3913 cur->full_path);
3914 if (ret < 0)
3915 goto out;
3916 if (S_ISDIR(ow_mode))
3917 orphanized_dir = true;
3920 * If ow_inode has its rename operation delayed
3921 * make sure that its orphanized name is used in
3922 * the source path when performing its rename
3923 * operation.
3925 if (is_waiting_for_move(sctx, ow_inode)) {
3926 wdm = get_waiting_dir_move(sctx,
3927 ow_inode);
3928 ASSERT(wdm);
3929 wdm->orphanized = true;
3933 * Make sure we clear our orphanized inode's
3934 * name from the name cache. This is because the
3935 * inode ow_inode might be an ancestor of some
3936 * other inode that will be orphanized as well
3937 * later and has an inode number greater than
3938 * sctx->send_progress. We need to prevent
3939 * future name lookups from using the old name
3940 * and get instead the orphan name.
3942 nce = name_cache_search(sctx, ow_inode, ow_gen);
3943 if (nce) {
3944 name_cache_delete(sctx, nce);
3945 kfree(nce);
3949 * ow_inode might currently be an ancestor of
3950 * cur_ino, therefore compute valid_path (the
3951 * current path of cur_ino) again because it
3952 * might contain the pre-orphanization name of
3953 * ow_inode, which is no longer valid.
3955 ret = is_ancestor(sctx->parent_root,
3956 ow_inode, ow_gen,
3957 sctx->cur_ino, NULL);
3958 if (ret > 0) {
3959 orphanized_ancestor = true;
3960 fs_path_reset(valid_path);
3961 ret = get_cur_path(sctx, sctx->cur_ino,
3962 sctx->cur_inode_gen,
3963 valid_path);
3965 if (ret < 0)
3966 goto out;
3967 } else {
3968 ret = send_unlink(sctx, cur->full_path);
3969 if (ret < 0)
3970 goto out;
3974 if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root) {
3975 ret = wait_for_dest_dir_move(sctx, cur, is_orphan);
3976 if (ret < 0)
3977 goto out;
3978 if (ret == 1) {
3979 can_rename = false;
3980 *pending_move = 1;
3984 if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root &&
3985 can_rename) {
3986 ret = wait_for_parent_move(sctx, cur, is_orphan);
3987 if (ret < 0)
3988 goto out;
3989 if (ret == 1) {
3990 can_rename = false;
3991 *pending_move = 1;
3996 * link/move the ref to the new place. If we have an orphan
3997 * inode, move it and update valid_path. If not, link or move
3998 * it depending on the inode mode.
4000 if (is_orphan && can_rename) {
4001 ret = send_rename(sctx, valid_path, cur->full_path);
4002 if (ret < 0)
4003 goto out;
4004 is_orphan = 0;
4005 ret = fs_path_copy(valid_path, cur->full_path);
4006 if (ret < 0)
4007 goto out;
4008 } else if (can_rename) {
4009 if (S_ISDIR(sctx->cur_inode_mode)) {
4011 * Dirs can't be linked, so move it. For moved
4012 * dirs, we always have one new and one deleted
4013 * ref. The deleted ref is ignored later.
4015 ret = send_rename(sctx, valid_path,
4016 cur->full_path);
4017 if (!ret)
4018 ret = fs_path_copy(valid_path,
4019 cur->full_path);
4020 if (ret < 0)
4021 goto out;
4022 } else {
4024 * We might have previously orphanized an inode
4025 * which is an ancestor of our current inode,
4026 * so our reference's full path, which was
4027 * computed before any such orphanizations, must
4028 * be updated.
4030 if (orphanized_dir) {
4031 ret = update_ref_path(sctx, cur);
4032 if (ret < 0)
4033 goto out;
4035 ret = send_link(sctx, cur->full_path,
4036 valid_path);
4037 if (ret < 0)
4038 goto out;
4041 ret = dup_ref(cur, &check_dirs);
4042 if (ret < 0)
4043 goto out;
4046 if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
4048 * Check if we can already rmdir the directory. If not,
4049 * orphanize it. For every dir item inside that gets deleted
4050 * later, we do this check again and rmdir it then if possible.
4051 * See the use of check_dirs for more details.
4053 ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4054 sctx->cur_ino);
4055 if (ret < 0)
4056 goto out;
4057 if (ret) {
4058 ret = send_rmdir(sctx, valid_path);
4059 if (ret < 0)
4060 goto out;
4061 } else if (!is_orphan) {
4062 ret = orphanize_inode(sctx, sctx->cur_ino,
4063 sctx->cur_inode_gen, valid_path);
4064 if (ret < 0)
4065 goto out;
4066 is_orphan = 1;
4069 list_for_each_entry(cur, &sctx->deleted_refs, list) {
4070 ret = dup_ref(cur, &check_dirs);
4071 if (ret < 0)
4072 goto out;
4074 } else if (S_ISDIR(sctx->cur_inode_mode) &&
4075 !list_empty(&sctx->deleted_refs)) {
4077 * We have a moved dir. Add the old parent to check_dirs
4079 cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
4080 list);
4081 ret = dup_ref(cur, &check_dirs);
4082 if (ret < 0)
4083 goto out;
4084 } else if (!S_ISDIR(sctx->cur_inode_mode)) {
4086 * We have a non dir inode. Go through all deleted refs and
4087 * unlink them if they were not already overwritten by other
4088 * inodes.
4090 list_for_each_entry(cur, &sctx->deleted_refs, list) {
4091 ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
4092 sctx->cur_ino, sctx->cur_inode_gen,
4093 cur->name, cur->name_len);
4094 if (ret < 0)
4095 goto out;
4096 if (!ret) {
4098 * If we orphanized any ancestor before, we need
4099 * to recompute the full path for deleted names,
4100 * since any such path was computed before we
4101 * processed any references and orphanized any
4102 * ancestor inode.
4104 if (orphanized_ancestor) {
4105 ret = update_ref_path(sctx, cur);
4106 if (ret < 0)
4107 goto out;
4109 ret = send_unlink(sctx, cur->full_path);
4110 if (ret < 0)
4111 goto out;
4113 ret = dup_ref(cur, &check_dirs);
4114 if (ret < 0)
4115 goto out;
4118 * If the inode is still orphan, unlink the orphan. This may
4119 * happen when a previous inode did overwrite the first ref
4120 * of this inode and no new refs were added for the current
4121 * inode. Unlinking does not mean that the inode is deleted in
4122 * all cases. There may still be links to this inode in other
4123 * places.
4125 if (is_orphan) {
4126 ret = send_unlink(sctx, valid_path);
4127 if (ret < 0)
4128 goto out;
4133 * We did collect all parent dirs where cur_inode was once located. We
4134 * now go through all these dirs and check if they are pending for
4135 * deletion and if it's finally possible to perform the rmdir now.
4136 * We also update the inode stats of the parent dirs here.
4138 list_for_each_entry(cur, &check_dirs, list) {
4140 * In case we had refs into dirs that were not processed yet,
4141 * we don't need to do the utime and rmdir logic for these dirs.
4142 * The dir will be processed later.
4144 if (cur->dir > sctx->cur_ino)
4145 continue;
4147 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
4148 if (ret < 0)
4149 goto out;
4151 if (ret == inode_state_did_create ||
4152 ret == inode_state_no_change) {
4153 /* TODO delayed utimes */
4154 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
4155 if (ret < 0)
4156 goto out;
4157 } else if (ret == inode_state_did_delete &&
4158 cur->dir != last_dir_ino_rm) {
4159 ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
4160 sctx->cur_ino);
4161 if (ret < 0)
4162 goto out;
4163 if (ret) {
4164 ret = get_cur_path(sctx, cur->dir,
4165 cur->dir_gen, valid_path);
4166 if (ret < 0)
4167 goto out;
4168 ret = send_rmdir(sctx, valid_path);
4169 if (ret < 0)
4170 goto out;
4171 last_dir_ino_rm = cur->dir;
4176 ret = 0;
4178 out:
4179 __free_recorded_refs(&check_dirs);
4180 free_recorded_refs(sctx);
4181 fs_path_free(valid_path);
4182 return ret;
4185 static int record_ref(struct btrfs_root *root, u64 dir, struct fs_path *name,
4186 void *ctx, struct list_head *refs)
4188 int ret = 0;
4189 struct send_ctx *sctx = ctx;
4190 struct fs_path *p;
4191 u64 gen;
4193 p = fs_path_alloc();
4194 if (!p)
4195 return -ENOMEM;
4197 ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
4198 NULL, NULL);
4199 if (ret < 0)
4200 goto out;
4202 ret = get_cur_path(sctx, dir, gen, p);
4203 if (ret < 0)
4204 goto out;
4205 ret = fs_path_add_path(p, name);
4206 if (ret < 0)
4207 goto out;
4209 ret = __record_ref(refs, dir, gen, p);
4211 out:
4212 if (ret)
4213 fs_path_free(p);
4214 return ret;
4217 static int __record_new_ref(int num, u64 dir, int index,
4218 struct fs_path *name,
4219 void *ctx)
4221 struct send_ctx *sctx = ctx;
4222 return record_ref(sctx->send_root, dir, name, ctx, &sctx->new_refs);
4226 static int __record_deleted_ref(int num, u64 dir, int index,
4227 struct fs_path *name,
4228 void *ctx)
4230 struct send_ctx *sctx = ctx;
4231 return record_ref(sctx->parent_root, dir, name, ctx,
4232 &sctx->deleted_refs);
4235 static int record_new_ref(struct send_ctx *sctx)
4237 int ret;
4239 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
4240 sctx->cmp_key, 0, __record_new_ref, sctx);
4241 if (ret < 0)
4242 goto out;
4243 ret = 0;
4245 out:
4246 return ret;
4249 static int record_deleted_ref(struct send_ctx *sctx)
4251 int ret;
4253 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
4254 sctx->cmp_key, 0, __record_deleted_ref, sctx);
4255 if (ret < 0)
4256 goto out;
4257 ret = 0;
4259 out:
4260 return ret;
4263 struct find_ref_ctx {
4264 u64 dir;
4265 u64 dir_gen;
4266 struct btrfs_root *root;
4267 struct fs_path *name;
4268 int found_idx;
4271 static int __find_iref(int num, u64 dir, int index,
4272 struct fs_path *name,
4273 void *ctx_)
4275 struct find_ref_ctx *ctx = ctx_;
4276 u64 dir_gen;
4277 int ret;
4279 if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
4280 strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
4282 * To avoid doing extra lookups we'll only do this if everything
4283 * else matches.
4285 ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
4286 NULL, NULL, NULL);
4287 if (ret)
4288 return ret;
4289 if (dir_gen != ctx->dir_gen)
4290 return 0;
4291 ctx->found_idx = num;
4292 return 1;
4294 return 0;
4297 static int find_iref(struct btrfs_root *root,
4298 struct btrfs_path *path,
4299 struct btrfs_key *key,
4300 u64 dir, u64 dir_gen, struct fs_path *name)
4302 int ret;
4303 struct find_ref_ctx ctx;
4305 ctx.dir = dir;
4306 ctx.name = name;
4307 ctx.dir_gen = dir_gen;
4308 ctx.found_idx = -1;
4309 ctx.root = root;
4311 ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
4312 if (ret < 0)
4313 return ret;
4315 if (ctx.found_idx == -1)
4316 return -ENOENT;
4318 return ctx.found_idx;
4321 static int __record_changed_new_ref(int num, u64 dir, int index,
4322 struct fs_path *name,
4323 void *ctx)
4325 u64 dir_gen;
4326 int ret;
4327 struct send_ctx *sctx = ctx;
4329 ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
4330 NULL, NULL, NULL);
4331 if (ret)
4332 return ret;
4334 ret = find_iref(sctx->parent_root, sctx->right_path,
4335 sctx->cmp_key, dir, dir_gen, name);
4336 if (ret == -ENOENT)
4337 ret = __record_new_ref(num, dir, index, name, sctx);
4338 else if (ret > 0)
4339 ret = 0;
4341 return ret;
4344 static int __record_changed_deleted_ref(int num, u64 dir, int index,
4345 struct fs_path *name,
4346 void *ctx)
4348 u64 dir_gen;
4349 int ret;
4350 struct send_ctx *sctx = ctx;
4352 ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
4353 NULL, NULL, NULL);
4354 if (ret)
4355 return ret;
4357 ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
4358 dir, dir_gen, name);
4359 if (ret == -ENOENT)
4360 ret = __record_deleted_ref(num, dir, index, name, sctx);
4361 else if (ret > 0)
4362 ret = 0;
4364 return ret;
4367 static int record_changed_ref(struct send_ctx *sctx)
4369 int ret = 0;
4371 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
4372 sctx->cmp_key, 0, __record_changed_new_ref, sctx);
4373 if (ret < 0)
4374 goto out;
4375 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
4376 sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
4377 if (ret < 0)
4378 goto out;
4379 ret = 0;
4381 out:
4382 return ret;
4386 * Record and process all refs at once. Needed when an inode changes the
4387 * generation number, which means that it was deleted and recreated.
4389 static int process_all_refs(struct send_ctx *sctx,
4390 enum btrfs_compare_tree_result cmd)
4392 int ret;
4393 struct btrfs_root *root;
4394 struct btrfs_path *path;
4395 struct btrfs_key key;
4396 struct btrfs_key found_key;
4397 struct extent_buffer *eb;
4398 int slot;
4399 iterate_inode_ref_t cb;
4400 int pending_move = 0;
4402 path = alloc_path_for_send();
4403 if (!path)
4404 return -ENOMEM;
4406 if (cmd == BTRFS_COMPARE_TREE_NEW) {
4407 root = sctx->send_root;
4408 cb = __record_new_ref;
4409 } else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
4410 root = sctx->parent_root;
4411 cb = __record_deleted_ref;
4412 } else {
4413 btrfs_err(sctx->send_root->fs_info,
4414 "Wrong command %d in process_all_refs", cmd);
4415 ret = -EINVAL;
4416 goto out;
4419 key.objectid = sctx->cmp_key->objectid;
4420 key.type = BTRFS_INODE_REF_KEY;
4421 key.offset = 0;
4422 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4423 if (ret < 0)
4424 goto out;
4426 while (1) {
4427 eb = path->nodes[0];
4428 slot = path->slots[0];
4429 if (slot >= btrfs_header_nritems(eb)) {
4430 ret = btrfs_next_leaf(root, path);
4431 if (ret < 0)
4432 goto out;
4433 else if (ret > 0)
4434 break;
4435 continue;
4438 btrfs_item_key_to_cpu(eb, &found_key, slot);
4440 if (found_key.objectid != key.objectid ||
4441 (found_key.type != BTRFS_INODE_REF_KEY &&
4442 found_key.type != BTRFS_INODE_EXTREF_KEY))
4443 break;
4445 ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
4446 if (ret < 0)
4447 goto out;
4449 path->slots[0]++;
4451 btrfs_release_path(path);
4454 * We don't actually care about pending_move as we are simply
4455 * re-creating this inode and will be rename'ing it into place once we
4456 * rename the parent directory.
4458 ret = process_recorded_refs(sctx, &pending_move);
4459 out:
4460 btrfs_free_path(path);
4461 return ret;
4464 static int send_set_xattr(struct send_ctx *sctx,
4465 struct fs_path *path,
4466 const char *name, int name_len,
4467 const char *data, int data_len)
4469 int ret = 0;
4471 ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
4472 if (ret < 0)
4473 goto out;
4475 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
4476 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
4477 TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
4479 ret = send_cmd(sctx);
4481 tlv_put_failure:
4482 out:
4483 return ret;
4486 static int send_remove_xattr(struct send_ctx *sctx,
4487 struct fs_path *path,
4488 const char *name, int name_len)
4490 int ret = 0;
4492 ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
4493 if (ret < 0)
4494 goto out;
4496 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
4497 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
4499 ret = send_cmd(sctx);
4501 tlv_put_failure:
4502 out:
4503 return ret;
4506 static int __process_new_xattr(int num, struct btrfs_key *di_key,
4507 const char *name, int name_len,
4508 const char *data, int data_len,
4509 u8 type, void *ctx)
4511 int ret;
4512 struct send_ctx *sctx = ctx;
4513 struct fs_path *p;
4514 struct posix_acl_xattr_header dummy_acl;
4516 p = fs_path_alloc();
4517 if (!p)
4518 return -ENOMEM;
4521 * This hack is needed because empty acls are stored as zero byte
4522 * data in xattrs. Problem with that is, that receiving these zero byte
4523 * acls will fail later. To fix this, we send a dummy acl list that
4524 * only contains the version number and no entries.
4526 if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
4527 !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
4528 if (data_len == 0) {
4529 dummy_acl.a_version =
4530 cpu_to_le32(POSIX_ACL_XATTR_VERSION);
4531 data = (char *)&dummy_acl;
4532 data_len = sizeof(dummy_acl);
4536 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4537 if (ret < 0)
4538 goto out;
4540 ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
4542 out:
4543 fs_path_free(p);
4544 return ret;
4547 static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
4548 const char *name, int name_len,
4549 const char *data, int data_len,
4550 u8 type, void *ctx)
4552 int ret;
4553 struct send_ctx *sctx = ctx;
4554 struct fs_path *p;
4556 p = fs_path_alloc();
4557 if (!p)
4558 return -ENOMEM;
4560 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4561 if (ret < 0)
4562 goto out;
4564 ret = send_remove_xattr(sctx, p, name, name_len);
4566 out:
4567 fs_path_free(p);
4568 return ret;
4571 static int process_new_xattr(struct send_ctx *sctx)
4573 int ret = 0;
4575 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4576 __process_new_xattr, sctx);
4578 return ret;
4581 static int process_deleted_xattr(struct send_ctx *sctx)
4583 return iterate_dir_item(sctx->parent_root, sctx->right_path,
4584 __process_deleted_xattr, sctx);
4587 struct find_xattr_ctx {
4588 const char *name;
4589 int name_len;
4590 int found_idx;
4591 char *found_data;
4592 int found_data_len;
4595 static int __find_xattr(int num, struct btrfs_key *di_key,
4596 const char *name, int name_len,
4597 const char *data, int data_len,
4598 u8 type, void *vctx)
4600 struct find_xattr_ctx *ctx = vctx;
4602 if (name_len == ctx->name_len &&
4603 strncmp(name, ctx->name, name_len) == 0) {
4604 ctx->found_idx = num;
4605 ctx->found_data_len = data_len;
4606 ctx->found_data = kmemdup(data, data_len, GFP_KERNEL);
4607 if (!ctx->found_data)
4608 return -ENOMEM;
4609 return 1;
4611 return 0;
4614 static int find_xattr(struct btrfs_root *root,
4615 struct btrfs_path *path,
4616 struct btrfs_key *key,
4617 const char *name, int name_len,
4618 char **data, int *data_len)
4620 int ret;
4621 struct find_xattr_ctx ctx;
4623 ctx.name = name;
4624 ctx.name_len = name_len;
4625 ctx.found_idx = -1;
4626 ctx.found_data = NULL;
4627 ctx.found_data_len = 0;
4629 ret = iterate_dir_item(root, path, __find_xattr, &ctx);
4630 if (ret < 0)
4631 return ret;
4633 if (ctx.found_idx == -1)
4634 return -ENOENT;
4635 if (data) {
4636 *data = ctx.found_data;
4637 *data_len = ctx.found_data_len;
4638 } else {
4639 kfree(ctx.found_data);
4641 return ctx.found_idx;
4645 static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
4646 const char *name, int name_len,
4647 const char *data, int data_len,
4648 u8 type, void *ctx)
4650 int ret;
4651 struct send_ctx *sctx = ctx;
4652 char *found_data = NULL;
4653 int found_data_len = 0;
4655 ret = find_xattr(sctx->parent_root, sctx->right_path,
4656 sctx->cmp_key, name, name_len, &found_data,
4657 &found_data_len);
4658 if (ret == -ENOENT) {
4659 ret = __process_new_xattr(num, di_key, name, name_len, data,
4660 data_len, type, ctx);
4661 } else if (ret >= 0) {
4662 if (data_len != found_data_len ||
4663 memcmp(data, found_data, data_len)) {
4664 ret = __process_new_xattr(num, di_key, name, name_len,
4665 data, data_len, type, ctx);
4666 } else {
4667 ret = 0;
4671 kfree(found_data);
4672 return ret;
4675 static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
4676 const char *name, int name_len,
4677 const char *data, int data_len,
4678 u8 type, void *ctx)
4680 int ret;
4681 struct send_ctx *sctx = ctx;
4683 ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
4684 name, name_len, NULL, NULL);
4685 if (ret == -ENOENT)
4686 ret = __process_deleted_xattr(num, di_key, name, name_len, data,
4687 data_len, type, ctx);
4688 else if (ret >= 0)
4689 ret = 0;
4691 return ret;
4694 static int process_changed_xattr(struct send_ctx *sctx)
4696 int ret = 0;
4698 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4699 __process_changed_new_xattr, sctx);
4700 if (ret < 0)
4701 goto out;
4702 ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4703 __process_changed_deleted_xattr, sctx);
4705 out:
4706 return ret;
4709 static int process_all_new_xattrs(struct send_ctx *sctx)
4711 int ret;
4712 struct btrfs_root *root;
4713 struct btrfs_path *path;
4714 struct btrfs_key key;
4715 struct btrfs_key found_key;
4716 struct extent_buffer *eb;
4717 int slot;
4719 path = alloc_path_for_send();
4720 if (!path)
4721 return -ENOMEM;
4723 root = sctx->send_root;
4725 key.objectid = sctx->cmp_key->objectid;
4726 key.type = BTRFS_XATTR_ITEM_KEY;
4727 key.offset = 0;
4728 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4729 if (ret < 0)
4730 goto out;
4732 while (1) {
4733 eb = path->nodes[0];
4734 slot = path->slots[0];
4735 if (slot >= btrfs_header_nritems(eb)) {
4736 ret = btrfs_next_leaf(root, path);
4737 if (ret < 0) {
4738 goto out;
4739 } else if (ret > 0) {
4740 ret = 0;
4741 break;
4743 continue;
4746 btrfs_item_key_to_cpu(eb, &found_key, slot);
4747 if (found_key.objectid != key.objectid ||
4748 found_key.type != key.type) {
4749 ret = 0;
4750 goto out;
4753 ret = iterate_dir_item(root, path, __process_new_xattr, sctx);
4754 if (ret < 0)
4755 goto out;
4757 path->slots[0]++;
4760 out:
4761 btrfs_free_path(path);
4762 return ret;
4765 static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
4767 struct btrfs_root *root = sctx->send_root;
4768 struct btrfs_fs_info *fs_info = root->fs_info;
4769 struct inode *inode;
4770 struct page *page;
4771 char *addr;
4772 struct btrfs_key key;
4773 pgoff_t index = offset >> PAGE_SHIFT;
4774 pgoff_t last_index;
4775 unsigned pg_offset = offset & ~PAGE_MASK;
4776 ssize_t ret = 0;
4778 key.objectid = sctx->cur_ino;
4779 key.type = BTRFS_INODE_ITEM_KEY;
4780 key.offset = 0;
4782 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
4783 if (IS_ERR(inode))
4784 return PTR_ERR(inode);
4786 if (offset + len > i_size_read(inode)) {
4787 if (offset > i_size_read(inode))
4788 len = 0;
4789 else
4790 len = offset - i_size_read(inode);
4792 if (len == 0)
4793 goto out;
4795 last_index = (offset + len - 1) >> PAGE_SHIFT;
4797 /* initial readahead */
4798 memset(&sctx->ra, 0, sizeof(struct file_ra_state));
4799 file_ra_state_init(&sctx->ra, inode->i_mapping);
4801 while (index <= last_index) {
4802 unsigned cur_len = min_t(unsigned, len,
4803 PAGE_SIZE - pg_offset);
4805 page = find_lock_page(inode->i_mapping, index);
4806 if (!page) {
4807 page_cache_sync_readahead(inode->i_mapping, &sctx->ra,
4808 NULL, index, last_index + 1 - index);
4810 page = find_or_create_page(inode->i_mapping, index,
4811 GFP_KERNEL);
4812 if (!page) {
4813 ret = -ENOMEM;
4814 break;
4818 if (PageReadahead(page)) {
4819 page_cache_async_readahead(inode->i_mapping, &sctx->ra,
4820 NULL, page, index, last_index + 1 - index);
4823 if (!PageUptodate(page)) {
4824 btrfs_readpage(NULL, page);
4825 lock_page(page);
4826 if (!PageUptodate(page)) {
4827 unlock_page(page);
4828 put_page(page);
4829 ret = -EIO;
4830 break;
4834 addr = kmap(page);
4835 memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len);
4836 kunmap(page);
4837 unlock_page(page);
4838 put_page(page);
4839 index++;
4840 pg_offset = 0;
4841 len -= cur_len;
4842 ret += cur_len;
4844 out:
4845 iput(inode);
4846 return ret;
4850 * Read some bytes from the current inode/file and send a write command to
4851 * user space.
4853 static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
4855 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
4856 int ret = 0;
4857 struct fs_path *p;
4858 ssize_t num_read = 0;
4860 p = fs_path_alloc();
4861 if (!p)
4862 return -ENOMEM;
4864 btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len);
4866 num_read = fill_read_buf(sctx, offset, len);
4867 if (num_read <= 0) {
4868 if (num_read < 0)
4869 ret = num_read;
4870 goto out;
4873 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4874 if (ret < 0)
4875 goto out;
4877 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4878 if (ret < 0)
4879 goto out;
4881 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4882 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4883 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
4885 ret = send_cmd(sctx);
4887 tlv_put_failure:
4888 out:
4889 fs_path_free(p);
4890 if (ret < 0)
4891 return ret;
4892 return num_read;
4896 * Send a clone command to user space.
4898 static int send_clone(struct send_ctx *sctx,
4899 u64 offset, u32 len,
4900 struct clone_root *clone_root)
4902 int ret = 0;
4903 struct fs_path *p;
4904 u64 gen;
4906 btrfs_debug(sctx->send_root->fs_info,
4907 "send_clone offset=%llu, len=%d, clone_root=%llu, clone_inode=%llu, clone_offset=%llu",
4908 offset, len, clone_root->root->objectid, clone_root->ino,
4909 clone_root->offset);
4911 p = fs_path_alloc();
4912 if (!p)
4913 return -ENOMEM;
4915 ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
4916 if (ret < 0)
4917 goto out;
4919 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4920 if (ret < 0)
4921 goto out;
4923 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4924 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
4925 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4927 if (clone_root->root == sctx->send_root) {
4928 ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
4929 &gen, NULL, NULL, NULL, NULL);
4930 if (ret < 0)
4931 goto out;
4932 ret = get_cur_path(sctx, clone_root->ino, gen, p);
4933 } else {
4934 ret = get_inode_path(clone_root->root, clone_root->ino, p);
4936 if (ret < 0)
4937 goto out;
4940 * If the parent we're using has a received_uuid set then use that as
4941 * our clone source as that is what we will look for when doing a
4942 * receive.
4944 * This covers the case that we create a snapshot off of a received
4945 * subvolume and then use that as the parent and try to receive on a
4946 * different host.
4948 if (!btrfs_is_empty_uuid(clone_root->root->root_item.received_uuid))
4949 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4950 clone_root->root->root_item.received_uuid);
4951 else
4952 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4953 clone_root->root->root_item.uuid);
4954 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
4955 le64_to_cpu(clone_root->root->root_item.ctransid));
4956 TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
4957 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
4958 clone_root->offset);
4960 ret = send_cmd(sctx);
4962 tlv_put_failure:
4963 out:
4964 fs_path_free(p);
4965 return ret;
4969 * Send an update extent command to user space.
4971 static int send_update_extent(struct send_ctx *sctx,
4972 u64 offset, u32 len)
4974 int ret = 0;
4975 struct fs_path *p;
4977 p = fs_path_alloc();
4978 if (!p)
4979 return -ENOMEM;
4981 ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
4982 if (ret < 0)
4983 goto out;
4985 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4986 if (ret < 0)
4987 goto out;
4989 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4990 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4991 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);
4993 ret = send_cmd(sctx);
4995 tlv_put_failure:
4996 out:
4997 fs_path_free(p);
4998 return ret;
5001 static int send_hole(struct send_ctx *sctx, u64 end)
5003 struct fs_path *p = NULL;
5004 u64 offset = sctx->cur_inode_last_extent;
5005 u64 len;
5006 int ret = 0;
5008 if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
5009 return send_update_extent(sctx, offset, end - offset);
5011 p = fs_path_alloc();
5012 if (!p)
5013 return -ENOMEM;
5014 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
5015 if (ret < 0)
5016 goto tlv_put_failure;
5017 memset(sctx->read_buf, 0, BTRFS_SEND_READ_SIZE);
5018 while (offset < end) {
5019 len = min_t(u64, end - offset, BTRFS_SEND_READ_SIZE);
5021 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
5022 if (ret < 0)
5023 break;
5024 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
5025 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
5026 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len);
5027 ret = send_cmd(sctx);
5028 if (ret < 0)
5029 break;
5030 offset += len;
5032 tlv_put_failure:
5033 fs_path_free(p);
5034 return ret;
5037 static int send_extent_data(struct send_ctx *sctx,
5038 const u64 offset,
5039 const u64 len)
5041 u64 sent = 0;
5043 if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
5044 return send_update_extent(sctx, offset, len);
5046 while (sent < len) {
5047 u64 size = len - sent;
5048 int ret;
5050 if (size > BTRFS_SEND_READ_SIZE)
5051 size = BTRFS_SEND_READ_SIZE;
5052 ret = send_write(sctx, offset + sent, size);
5053 if (ret < 0)
5054 return ret;
5055 if (!ret)
5056 break;
5057 sent += ret;
5059 return 0;
5062 static int clone_range(struct send_ctx *sctx,
5063 struct clone_root *clone_root,
5064 const u64 disk_byte,
5065 u64 data_offset,
5066 u64 offset,
5067 u64 len)
5069 struct btrfs_path *path;
5070 struct btrfs_key key;
5071 int ret;
5074 * Prevent cloning from a zero offset with a length matching the sector
5075 * size because in some scenarios this will make the receiver fail.
5077 * For example, if in the source filesystem the extent at offset 0
5078 * has a length of sectorsize and it was written using direct IO, then
5079 * it can never be an inline extent (even if compression is enabled).
5080 * Then this extent can be cloned in the original filesystem to a non
5081 * zero file offset, but it may not be possible to clone in the
5082 * destination filesystem because it can be inlined due to compression
5083 * on the destination filesystem (as the receiver's write operations are
5084 * always done using buffered IO). The same happens when the original
5085 * filesystem does not have compression enabled but the destination
5086 * filesystem has.
5088 if (clone_root->offset == 0 &&
5089 len == sctx->send_root->fs_info->sectorsize)
5090 return send_extent_data(sctx, offset, len);
5092 path = alloc_path_for_send();
5093 if (!path)
5094 return -ENOMEM;
5097 * We can't send a clone operation for the entire range if we find
5098 * extent items in the respective range in the source file that
5099 * refer to different extents or if we find holes.
5100 * So check for that and do a mix of clone and regular write/copy
5101 * operations if needed.
5103 * Example:
5105 * mkfs.btrfs -f /dev/sda
5106 * mount /dev/sda /mnt
5107 * xfs_io -f -c "pwrite -S 0xaa 0K 100K" /mnt/foo
5108 * cp --reflink=always /mnt/foo /mnt/bar
5109 * xfs_io -c "pwrite -S 0xbb 50K 50K" /mnt/foo
5110 * btrfs subvolume snapshot -r /mnt /mnt/snap
5112 * If when we send the snapshot and we are processing file bar (which
5113 * has a higher inode number than foo) we blindly send a clone operation
5114 * for the [0, 100K[ range from foo to bar, the receiver ends up getting
5115 * a file bar that matches the content of file foo - iow, doesn't match
5116 * the content from bar in the original filesystem.
5118 key.objectid = clone_root->ino;
5119 key.type = BTRFS_EXTENT_DATA_KEY;
5120 key.offset = clone_root->offset;
5121 ret = btrfs_search_slot(NULL, clone_root->root, &key, path, 0, 0);
5122 if (ret < 0)
5123 goto out;
5124 if (ret > 0 && path->slots[0] > 0) {
5125 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
5126 if (key.objectid == clone_root->ino &&
5127 key.type == BTRFS_EXTENT_DATA_KEY)
5128 path->slots[0]--;
5131 while (true) {
5132 struct extent_buffer *leaf = path->nodes[0];
5133 int slot = path->slots[0];
5134 struct btrfs_file_extent_item *ei;
5135 u8 type;
5136 u64 ext_len;
5137 u64 clone_len;
5139 if (slot >= btrfs_header_nritems(leaf)) {
5140 ret = btrfs_next_leaf(clone_root->root, path);
5141 if (ret < 0)
5142 goto out;
5143 else if (ret > 0)
5144 break;
5145 continue;
5148 btrfs_item_key_to_cpu(leaf, &key, slot);
5151 * We might have an implicit trailing hole (NO_HOLES feature
5152 * enabled). We deal with it after leaving this loop.
5154 if (key.objectid != clone_root->ino ||
5155 key.type != BTRFS_EXTENT_DATA_KEY)
5156 break;
5158 ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5159 type = btrfs_file_extent_type(leaf, ei);
5160 if (type == BTRFS_FILE_EXTENT_INLINE) {
5161 ext_len = btrfs_file_extent_inline_len(leaf, slot, ei);
5162 ext_len = PAGE_ALIGN(ext_len);
5163 } else {
5164 ext_len = btrfs_file_extent_num_bytes(leaf, ei);
5167 if (key.offset + ext_len <= clone_root->offset)
5168 goto next;
5170 if (key.offset > clone_root->offset) {
5171 /* Implicit hole, NO_HOLES feature enabled. */
5172 u64 hole_len = key.offset - clone_root->offset;
5174 if (hole_len > len)
5175 hole_len = len;
5176 ret = send_extent_data(sctx, offset, hole_len);
5177 if (ret < 0)
5178 goto out;
5180 len -= hole_len;
5181 if (len == 0)
5182 break;
5183 offset += hole_len;
5184 clone_root->offset += hole_len;
5185 data_offset += hole_len;
5188 if (key.offset >= clone_root->offset + len)
5189 break;
5191 clone_len = min_t(u64, ext_len, len);
5193 if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte &&
5194 btrfs_file_extent_offset(leaf, ei) == data_offset)
5195 ret = send_clone(sctx, offset, clone_len, clone_root);
5196 else
5197 ret = send_extent_data(sctx, offset, clone_len);
5199 if (ret < 0)
5200 goto out;
5202 len -= clone_len;
5203 if (len == 0)
5204 break;
5205 offset += clone_len;
5206 clone_root->offset += clone_len;
5207 data_offset += clone_len;
5208 next:
5209 path->slots[0]++;
5212 if (len > 0)
5213 ret = send_extent_data(sctx, offset, len);
5214 else
5215 ret = 0;
5216 out:
5217 btrfs_free_path(path);
5218 return ret;
5221 static int send_write_or_clone(struct send_ctx *sctx,
5222 struct btrfs_path *path,
5223 struct btrfs_key *key,
5224 struct clone_root *clone_root)
5226 int ret = 0;
5227 struct btrfs_file_extent_item *ei;
5228 u64 offset = key->offset;
5229 u64 len;
5230 u8 type;
5231 u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
5233 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
5234 struct btrfs_file_extent_item);
5235 type = btrfs_file_extent_type(path->nodes[0], ei);
5236 if (type == BTRFS_FILE_EXTENT_INLINE) {
5237 len = btrfs_file_extent_inline_len(path->nodes[0],
5238 path->slots[0], ei);
5240 * it is possible the inline item won't cover the whole page,
5241 * but there may be items after this page. Make
5242 * sure to send the whole thing
5244 len = PAGE_ALIGN(len);
5245 } else {
5246 len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
5249 if (offset + len > sctx->cur_inode_size)
5250 len = sctx->cur_inode_size - offset;
5251 if (len == 0) {
5252 ret = 0;
5253 goto out;
5256 if (clone_root && IS_ALIGNED(offset + len, bs)) {
5257 u64 disk_byte;
5258 u64 data_offset;
5260 disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei);
5261 data_offset = btrfs_file_extent_offset(path->nodes[0], ei);
5262 ret = clone_range(sctx, clone_root, disk_byte, data_offset,
5263 offset, len);
5264 } else {
5265 ret = send_extent_data(sctx, offset, len);
5267 out:
5268 return ret;
5271 static int is_extent_unchanged(struct send_ctx *sctx,
5272 struct btrfs_path *left_path,
5273 struct btrfs_key *ekey)
5275 int ret = 0;
5276 struct btrfs_key key;
5277 struct btrfs_path *path = NULL;
5278 struct extent_buffer *eb;
5279 int slot;
5280 struct btrfs_key found_key;
5281 struct btrfs_file_extent_item *ei;
5282 u64 left_disknr;
5283 u64 right_disknr;
5284 u64 left_offset;
5285 u64 right_offset;
5286 u64 left_offset_fixed;
5287 u64 left_len;
5288 u64 right_len;
5289 u64 left_gen;
5290 u64 right_gen;
5291 u8 left_type;
5292 u8 right_type;
5294 path = alloc_path_for_send();
5295 if (!path)
5296 return -ENOMEM;
5298 eb = left_path->nodes[0];
5299 slot = left_path->slots[0];
5300 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
5301 left_type = btrfs_file_extent_type(eb, ei);
5303 if (left_type != BTRFS_FILE_EXTENT_REG) {
5304 ret = 0;
5305 goto out;
5307 left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
5308 left_len = btrfs_file_extent_num_bytes(eb, ei);
5309 left_offset = btrfs_file_extent_offset(eb, ei);
5310 left_gen = btrfs_file_extent_generation(eb, ei);
5313 * Following comments will refer to these graphics. L is the left
5314 * extents which we are checking at the moment. 1-8 are the right
5315 * extents that we iterate.
5317 * |-----L-----|
5318 * |-1-|-2a-|-3-|-4-|-5-|-6-|
5320 * |-----L-----|
5321 * |--1--|-2b-|...(same as above)
5323 * Alternative situation. Happens on files where extents got split.
5324 * |-----L-----|
5325 * |-----------7-----------|-6-|
5327 * Alternative situation. Happens on files which got larger.
5328 * |-----L-----|
5329 * |-8-|
5330 * Nothing follows after 8.
5333 key.objectid = ekey->objectid;
5334 key.type = BTRFS_EXTENT_DATA_KEY;
5335 key.offset = ekey->offset;
5336 ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
5337 if (ret < 0)
5338 goto out;
5339 if (ret) {
5340 ret = 0;
5341 goto out;
5345 * Handle special case where the right side has no extents at all.
5347 eb = path->nodes[0];
5348 slot = path->slots[0];
5349 btrfs_item_key_to_cpu(eb, &found_key, slot);
5350 if (found_key.objectid != key.objectid ||
5351 found_key.type != key.type) {
5352 /* If we're a hole then just pretend nothing changed */
5353 ret = (left_disknr) ? 0 : 1;
5354 goto out;
5358 * We're now on 2a, 2b or 7.
5360 key = found_key;
5361 while (key.offset < ekey->offset + left_len) {
5362 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
5363 right_type = btrfs_file_extent_type(eb, ei);
5364 if (right_type != BTRFS_FILE_EXTENT_REG &&
5365 right_type != BTRFS_FILE_EXTENT_INLINE) {
5366 ret = 0;
5367 goto out;
5370 if (right_type == BTRFS_FILE_EXTENT_INLINE) {
5371 right_len = btrfs_file_extent_inline_len(eb, slot, ei);
5372 right_len = PAGE_ALIGN(right_len);
5373 } else {
5374 right_len = btrfs_file_extent_num_bytes(eb, ei);
5378 * Are we at extent 8? If yes, we know the extent is changed.
5379 * This may only happen on the first iteration.
5381 if (found_key.offset + right_len <= ekey->offset) {
5382 /* If we're a hole just pretend nothing changed */
5383 ret = (left_disknr) ? 0 : 1;
5384 goto out;
5388 * We just wanted to see if when we have an inline extent, what
5389 * follows it is a regular extent (wanted to check the above
5390 * condition for inline extents too). This should normally not
5391 * happen but it's possible for example when we have an inline
5392 * compressed extent representing data with a size matching
5393 * the page size (currently the same as sector size).
5395 if (right_type == BTRFS_FILE_EXTENT_INLINE) {
5396 ret = 0;
5397 goto out;
5400 right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
5401 right_offset = btrfs_file_extent_offset(eb, ei);
5402 right_gen = btrfs_file_extent_generation(eb, ei);
5404 left_offset_fixed = left_offset;
5405 if (key.offset < ekey->offset) {
5406 /* Fix the right offset for 2a and 7. */
5407 right_offset += ekey->offset - key.offset;
5408 } else {
5409 /* Fix the left offset for all behind 2a and 2b */
5410 left_offset_fixed += key.offset - ekey->offset;
5414 * Check if we have the same extent.
5416 if (left_disknr != right_disknr ||
5417 left_offset_fixed != right_offset ||
5418 left_gen != right_gen) {
5419 ret = 0;
5420 goto out;
5424 * Go to the next extent.
5426 ret = btrfs_next_item(sctx->parent_root, path);
5427 if (ret < 0)
5428 goto out;
5429 if (!ret) {
5430 eb = path->nodes[0];
5431 slot = path->slots[0];
5432 btrfs_item_key_to_cpu(eb, &found_key, slot);
5434 if (ret || found_key.objectid != key.objectid ||
5435 found_key.type != key.type) {
5436 key.offset += right_len;
5437 break;
5439 if (found_key.offset != key.offset + right_len) {
5440 ret = 0;
5441 goto out;
5443 key = found_key;
5447 * We're now behind the left extent (treat as unchanged) or at the end
5448 * of the right side (treat as changed).
5450 if (key.offset >= ekey->offset + left_len)
5451 ret = 1;
5452 else
5453 ret = 0;
5456 out:
5457 btrfs_free_path(path);
5458 return ret;
5461 static int get_last_extent(struct send_ctx *sctx, u64 offset)
5463 struct btrfs_path *path;
5464 struct btrfs_root *root = sctx->send_root;
5465 struct btrfs_file_extent_item *fi;
5466 struct btrfs_key key;
5467 u64 extent_end;
5468 u8 type;
5469 int ret;
5471 path = alloc_path_for_send();
5472 if (!path)
5473 return -ENOMEM;
5475 sctx->cur_inode_last_extent = 0;
5477 key.objectid = sctx->cur_ino;
5478 key.type = BTRFS_EXTENT_DATA_KEY;
5479 key.offset = offset;
5480 ret = btrfs_search_slot_for_read(root, &key, path, 0, 1);
5481 if (ret < 0)
5482 goto out;
5483 ret = 0;
5484 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
5485 if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY)
5486 goto out;
5488 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
5489 struct btrfs_file_extent_item);
5490 type = btrfs_file_extent_type(path->nodes[0], fi);
5491 if (type == BTRFS_FILE_EXTENT_INLINE) {
5492 u64 size = btrfs_file_extent_inline_len(path->nodes[0],
5493 path->slots[0], fi);
5494 extent_end = ALIGN(key.offset + size,
5495 sctx->send_root->fs_info->sectorsize);
5496 } else {
5497 extent_end = key.offset +
5498 btrfs_file_extent_num_bytes(path->nodes[0], fi);
5500 sctx->cur_inode_last_extent = extent_end;
5501 out:
5502 btrfs_free_path(path);
5503 return ret;
5506 static int range_is_hole_in_parent(struct send_ctx *sctx,
5507 const u64 start,
5508 const u64 end)
5510 struct btrfs_path *path;
5511 struct btrfs_key key;
5512 struct btrfs_root *root = sctx->parent_root;
5513 u64 search_start = start;
5514 int ret;
5516 path = alloc_path_for_send();
5517 if (!path)
5518 return -ENOMEM;
5520 key.objectid = sctx->cur_ino;
5521 key.type = BTRFS_EXTENT_DATA_KEY;
5522 key.offset = search_start;
5523 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5524 if (ret < 0)
5525 goto out;
5526 if (ret > 0 && path->slots[0] > 0)
5527 path->slots[0]--;
5529 while (search_start < end) {
5530 struct extent_buffer *leaf = path->nodes[0];
5531 int slot = path->slots[0];
5532 struct btrfs_file_extent_item *fi;
5533 u64 extent_end;
5535 if (slot >= btrfs_header_nritems(leaf)) {
5536 ret = btrfs_next_leaf(root, path);
5537 if (ret < 0)
5538 goto out;
5539 else if (ret > 0)
5540 break;
5541 continue;
5544 btrfs_item_key_to_cpu(leaf, &key, slot);
5545 if (key.objectid < sctx->cur_ino ||
5546 key.type < BTRFS_EXTENT_DATA_KEY)
5547 goto next;
5548 if (key.objectid > sctx->cur_ino ||
5549 key.type > BTRFS_EXTENT_DATA_KEY ||
5550 key.offset >= end)
5551 break;
5553 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5554 if (btrfs_file_extent_type(leaf, fi) ==
5555 BTRFS_FILE_EXTENT_INLINE) {
5556 u64 size = btrfs_file_extent_inline_len(leaf, slot, fi);
5558 extent_end = ALIGN(key.offset + size,
5559 root->fs_info->sectorsize);
5560 } else {
5561 extent_end = key.offset +
5562 btrfs_file_extent_num_bytes(leaf, fi);
5564 if (extent_end <= start)
5565 goto next;
5566 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) {
5567 search_start = extent_end;
5568 goto next;
5570 ret = 0;
5571 goto out;
5572 next:
5573 path->slots[0]++;
5575 ret = 1;
5576 out:
5577 btrfs_free_path(path);
5578 return ret;
5581 static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
5582 struct btrfs_key *key)
5584 struct btrfs_file_extent_item *fi;
5585 u64 extent_end;
5586 u8 type;
5587 int ret = 0;
5589 if (sctx->cur_ino != key->objectid || !need_send_hole(sctx))
5590 return 0;
5592 if (sctx->cur_inode_last_extent == (u64)-1) {
5593 ret = get_last_extent(sctx, key->offset - 1);
5594 if (ret)
5595 return ret;
5598 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
5599 struct btrfs_file_extent_item);
5600 type = btrfs_file_extent_type(path->nodes[0], fi);
5601 if (type == BTRFS_FILE_EXTENT_INLINE) {
5602 u64 size = btrfs_file_extent_inline_len(path->nodes[0],
5603 path->slots[0], fi);
5604 extent_end = ALIGN(key->offset + size,
5605 sctx->send_root->fs_info->sectorsize);
5606 } else {
5607 extent_end = key->offset +
5608 btrfs_file_extent_num_bytes(path->nodes[0], fi);
5611 if (path->slots[0] == 0 &&
5612 sctx->cur_inode_last_extent < key->offset) {
5614 * We might have skipped entire leafs that contained only
5615 * file extent items for our current inode. These leafs have
5616 * a generation number smaller (older) than the one in the
5617 * current leaf and the leaf our last extent came from, and
5618 * are located between these 2 leafs.
5620 ret = get_last_extent(sctx, key->offset - 1);
5621 if (ret)
5622 return ret;
5625 if (sctx->cur_inode_last_extent < key->offset) {
5626 ret = range_is_hole_in_parent(sctx,
5627 sctx->cur_inode_last_extent,
5628 key->offset);
5629 if (ret < 0)
5630 return ret;
5631 else if (ret == 0)
5632 ret = send_hole(sctx, key->offset);
5633 else
5634 ret = 0;
5636 sctx->cur_inode_last_extent = extent_end;
5637 return ret;
5640 static int process_extent(struct send_ctx *sctx,
5641 struct btrfs_path *path,
5642 struct btrfs_key *key)
5644 struct clone_root *found_clone = NULL;
5645 int ret = 0;
5647 if (S_ISLNK(sctx->cur_inode_mode))
5648 return 0;
5650 if (sctx->parent_root && !sctx->cur_inode_new) {
5651 ret = is_extent_unchanged(sctx, path, key);
5652 if (ret < 0)
5653 goto out;
5654 if (ret) {
5655 ret = 0;
5656 goto out_hole;
5658 } else {
5659 struct btrfs_file_extent_item *ei;
5660 u8 type;
5662 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
5663 struct btrfs_file_extent_item);
5664 type = btrfs_file_extent_type(path->nodes[0], ei);
5665 if (type == BTRFS_FILE_EXTENT_PREALLOC ||
5666 type == BTRFS_FILE_EXTENT_REG) {
5668 * The send spec does not have a prealloc command yet,
5669 * so just leave a hole for prealloc'ed extents until
5670 * we have enough commands queued up to justify rev'ing
5671 * the send spec.
5673 if (type == BTRFS_FILE_EXTENT_PREALLOC) {
5674 ret = 0;
5675 goto out;
5678 /* Have a hole, just skip it. */
5679 if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
5680 ret = 0;
5681 goto out;
5686 ret = find_extent_clone(sctx, path, key->objectid, key->offset,
5687 sctx->cur_inode_size, &found_clone);
5688 if (ret != -ENOENT && ret < 0)
5689 goto out;
5691 ret = send_write_or_clone(sctx, path, key, found_clone);
5692 if (ret)
5693 goto out;
5694 out_hole:
5695 ret = maybe_send_hole(sctx, path, key);
5696 out:
5697 return ret;
5700 static int process_all_extents(struct send_ctx *sctx)
5702 int ret;
5703 struct btrfs_root *root;
5704 struct btrfs_path *path;
5705 struct btrfs_key key;
5706 struct btrfs_key found_key;
5707 struct extent_buffer *eb;
5708 int slot;
5710 root = sctx->send_root;
5711 path = alloc_path_for_send();
5712 if (!path)
5713 return -ENOMEM;
5715 key.objectid = sctx->cmp_key->objectid;
5716 key.type = BTRFS_EXTENT_DATA_KEY;
5717 key.offset = 0;
5718 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5719 if (ret < 0)
5720 goto out;
5722 while (1) {
5723 eb = path->nodes[0];
5724 slot = path->slots[0];
5726 if (slot >= btrfs_header_nritems(eb)) {
5727 ret = btrfs_next_leaf(root, path);
5728 if (ret < 0) {
5729 goto out;
5730 } else if (ret > 0) {
5731 ret = 0;
5732 break;
5734 continue;
5737 btrfs_item_key_to_cpu(eb, &found_key, slot);
5739 if (found_key.objectid != key.objectid ||
5740 found_key.type != key.type) {
5741 ret = 0;
5742 goto out;
5745 ret = process_extent(sctx, path, &found_key);
5746 if (ret < 0)
5747 goto out;
5749 path->slots[0]++;
5752 out:
5753 btrfs_free_path(path);
5754 return ret;
5757 static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
5758 int *pending_move,
5759 int *refs_processed)
5761 int ret = 0;
5763 if (sctx->cur_ino == 0)
5764 goto out;
5765 if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
5766 sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
5767 goto out;
5768 if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
5769 goto out;
5771 ret = process_recorded_refs(sctx, pending_move);
5772 if (ret < 0)
5773 goto out;
5775 *refs_processed = 1;
5776 out:
5777 return ret;
5780 static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
5782 int ret = 0;
5783 u64 left_mode;
5784 u64 left_uid;
5785 u64 left_gid;
5786 u64 right_mode;
5787 u64 right_uid;
5788 u64 right_gid;
5789 int need_chmod = 0;
5790 int need_chown = 0;
5791 int pending_move = 0;
5792 int refs_processed = 0;
5794 ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
5795 &refs_processed);
5796 if (ret < 0)
5797 goto out;
5800 * We have processed the refs and thus need to advance send_progress.
5801 * Now, calls to get_cur_xxx will take the updated refs of the current
5802 * inode into account.
5804 * On the other hand, if our current inode is a directory and couldn't
5805 * be moved/renamed because its parent was renamed/moved too and it has
5806 * a higher inode number, we can only move/rename our current inode
5807 * after we moved/renamed its parent. Therefore in this case operate on
5808 * the old path (pre move/rename) of our current inode, and the
5809 * move/rename will be performed later.
5811 if (refs_processed && !pending_move)
5812 sctx->send_progress = sctx->cur_ino + 1;
5814 if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
5815 goto out;
5816 if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
5817 goto out;
5819 ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
5820 &left_mode, &left_uid, &left_gid, NULL);
5821 if (ret < 0)
5822 goto out;
5824 if (!sctx->parent_root || sctx->cur_inode_new) {
5825 need_chown = 1;
5826 if (!S_ISLNK(sctx->cur_inode_mode))
5827 need_chmod = 1;
5828 } else {
5829 ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
5830 NULL, NULL, &right_mode, &right_uid,
5831 &right_gid, NULL);
5832 if (ret < 0)
5833 goto out;
5835 if (left_uid != right_uid || left_gid != right_gid)
5836 need_chown = 1;
5837 if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
5838 need_chmod = 1;
5841 if (S_ISREG(sctx->cur_inode_mode)) {
5842 if (need_send_hole(sctx)) {
5843 if (sctx->cur_inode_last_extent == (u64)-1 ||
5844 sctx->cur_inode_last_extent <
5845 sctx->cur_inode_size) {
5846 ret = get_last_extent(sctx, (u64)-1);
5847 if (ret)
5848 goto out;
5850 if (sctx->cur_inode_last_extent <
5851 sctx->cur_inode_size) {
5852 ret = send_hole(sctx, sctx->cur_inode_size);
5853 if (ret)
5854 goto out;
5857 ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5858 sctx->cur_inode_size);
5859 if (ret < 0)
5860 goto out;
5863 if (need_chown) {
5864 ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5865 left_uid, left_gid);
5866 if (ret < 0)
5867 goto out;
5869 if (need_chmod) {
5870 ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5871 left_mode);
5872 if (ret < 0)
5873 goto out;
5877 * If other directory inodes depended on our current directory
5878 * inode's move/rename, now do their move/rename operations.
5880 if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
5881 ret = apply_children_dir_moves(sctx);
5882 if (ret)
5883 goto out;
5885 * Need to send that every time, no matter if it actually
5886 * changed between the two trees as we have done changes to
5887 * the inode before. If our inode is a directory and it's
5888 * waiting to be moved/renamed, we will send its utimes when
5889 * it's moved/renamed, therefore we don't need to do it here.
5891 sctx->send_progress = sctx->cur_ino + 1;
5892 ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
5893 if (ret < 0)
5894 goto out;
5897 out:
5898 return ret;
5901 static int changed_inode(struct send_ctx *sctx,
5902 enum btrfs_compare_tree_result result)
5904 int ret = 0;
5905 struct btrfs_key *key = sctx->cmp_key;
5906 struct btrfs_inode_item *left_ii = NULL;
5907 struct btrfs_inode_item *right_ii = NULL;
5908 u64 left_gen = 0;
5909 u64 right_gen = 0;
5911 sctx->cur_ino = key->objectid;
5912 sctx->cur_inode_new_gen = 0;
5913 sctx->cur_inode_last_extent = (u64)-1;
5916 * Set send_progress to current inode. This will tell all get_cur_xxx
5917 * functions that the current inode's refs are not updated yet. Later,
5918 * when process_recorded_refs is finished, it is set to cur_ino + 1.
5920 sctx->send_progress = sctx->cur_ino;
5922 if (result == BTRFS_COMPARE_TREE_NEW ||
5923 result == BTRFS_COMPARE_TREE_CHANGED) {
5924 left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
5925 sctx->left_path->slots[0],
5926 struct btrfs_inode_item);
5927 left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
5928 left_ii);
5929 } else {
5930 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
5931 sctx->right_path->slots[0],
5932 struct btrfs_inode_item);
5933 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
5934 right_ii);
5936 if (result == BTRFS_COMPARE_TREE_CHANGED) {
5937 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
5938 sctx->right_path->slots[0],
5939 struct btrfs_inode_item);
5941 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
5942 right_ii);
5945 * The cur_ino = root dir case is special here. We can't treat
5946 * the inode as deleted+reused because it would generate a
5947 * stream that tries to delete/mkdir the root dir.
5949 if (left_gen != right_gen &&
5950 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5951 sctx->cur_inode_new_gen = 1;
5954 if (result == BTRFS_COMPARE_TREE_NEW) {
5955 sctx->cur_inode_gen = left_gen;
5956 sctx->cur_inode_new = 1;
5957 sctx->cur_inode_deleted = 0;
5958 sctx->cur_inode_size = btrfs_inode_size(
5959 sctx->left_path->nodes[0], left_ii);
5960 sctx->cur_inode_mode = btrfs_inode_mode(
5961 sctx->left_path->nodes[0], left_ii);
5962 sctx->cur_inode_rdev = btrfs_inode_rdev(
5963 sctx->left_path->nodes[0], left_ii);
5964 if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5965 ret = send_create_inode_if_needed(sctx);
5966 } else if (result == BTRFS_COMPARE_TREE_DELETED) {
5967 sctx->cur_inode_gen = right_gen;
5968 sctx->cur_inode_new = 0;
5969 sctx->cur_inode_deleted = 1;
5970 sctx->cur_inode_size = btrfs_inode_size(
5971 sctx->right_path->nodes[0], right_ii);
5972 sctx->cur_inode_mode = btrfs_inode_mode(
5973 sctx->right_path->nodes[0], right_ii);
5974 } else if (result == BTRFS_COMPARE_TREE_CHANGED) {
5976 * We need to do some special handling in case the inode was
5977 * reported as changed with a changed generation number. This
5978 * means that the original inode was deleted and new inode
5979 * reused the same inum. So we have to treat the old inode as
5980 * deleted and the new one as new.
5982 if (sctx->cur_inode_new_gen) {
5984 * First, process the inode as if it was deleted.
5986 sctx->cur_inode_gen = right_gen;
5987 sctx->cur_inode_new = 0;
5988 sctx->cur_inode_deleted = 1;
5989 sctx->cur_inode_size = btrfs_inode_size(
5990 sctx->right_path->nodes[0], right_ii);
5991 sctx->cur_inode_mode = btrfs_inode_mode(
5992 sctx->right_path->nodes[0], right_ii);
5993 ret = process_all_refs(sctx,
5994 BTRFS_COMPARE_TREE_DELETED);
5995 if (ret < 0)
5996 goto out;
5999 * Now process the inode as if it was new.
6001 sctx->cur_inode_gen = left_gen;
6002 sctx->cur_inode_new = 1;
6003 sctx->cur_inode_deleted = 0;
6004 sctx->cur_inode_size = btrfs_inode_size(
6005 sctx->left_path->nodes[0], left_ii);
6006 sctx->cur_inode_mode = btrfs_inode_mode(
6007 sctx->left_path->nodes[0], left_ii);
6008 sctx->cur_inode_rdev = btrfs_inode_rdev(
6009 sctx->left_path->nodes[0], left_ii);
6010 ret = send_create_inode_if_needed(sctx);
6011 if (ret < 0)
6012 goto out;
6014 ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
6015 if (ret < 0)
6016 goto out;
6018 * Advance send_progress now as we did not get into
6019 * process_recorded_refs_if_needed in the new_gen case.
6021 sctx->send_progress = sctx->cur_ino + 1;
6024 * Now process all extents and xattrs of the inode as if
6025 * they were all new.
6027 ret = process_all_extents(sctx);
6028 if (ret < 0)
6029 goto out;
6030 ret = process_all_new_xattrs(sctx);
6031 if (ret < 0)
6032 goto out;
6033 } else {
6034 sctx->cur_inode_gen = left_gen;
6035 sctx->cur_inode_new = 0;
6036 sctx->cur_inode_new_gen = 0;
6037 sctx->cur_inode_deleted = 0;
6038 sctx->cur_inode_size = btrfs_inode_size(
6039 sctx->left_path->nodes[0], left_ii);
6040 sctx->cur_inode_mode = btrfs_inode_mode(
6041 sctx->left_path->nodes[0], left_ii);
6045 out:
6046 return ret;
6050 * We have to process new refs before deleted refs, but compare_trees gives us
6051 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
6052 * first and later process them in process_recorded_refs.
6053 * For the cur_inode_new_gen case, we skip recording completely because
6054 * changed_inode did already initiate processing of refs. The reason for this is
6055 * that in this case, compare_tree actually compares the refs of 2 different
6056 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
6057 * refs of the right tree as deleted and all refs of the left tree as new.
6059 static int changed_ref(struct send_ctx *sctx,
6060 enum btrfs_compare_tree_result result)
6062 int ret = 0;
6064 if (sctx->cur_ino != sctx->cmp_key->objectid) {
6065 inconsistent_snapshot_error(sctx, result, "reference");
6066 return -EIO;
6069 if (!sctx->cur_inode_new_gen &&
6070 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
6071 if (result == BTRFS_COMPARE_TREE_NEW)
6072 ret = record_new_ref(sctx);
6073 else if (result == BTRFS_COMPARE_TREE_DELETED)
6074 ret = record_deleted_ref(sctx);
6075 else if (result == BTRFS_COMPARE_TREE_CHANGED)
6076 ret = record_changed_ref(sctx);
6079 return ret;
6083 * Process new/deleted/changed xattrs. We skip processing in the
6084 * cur_inode_new_gen case because changed_inode did already initiate processing
6085 * of xattrs. The reason is the same as in changed_ref
6087 static int changed_xattr(struct send_ctx *sctx,
6088 enum btrfs_compare_tree_result result)
6090 int ret = 0;
6092 if (sctx->cur_ino != sctx->cmp_key->objectid) {
6093 inconsistent_snapshot_error(sctx, result, "xattr");
6094 return -EIO;
6097 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
6098 if (result == BTRFS_COMPARE_TREE_NEW)
6099 ret = process_new_xattr(sctx);
6100 else if (result == BTRFS_COMPARE_TREE_DELETED)
6101 ret = process_deleted_xattr(sctx);
6102 else if (result == BTRFS_COMPARE_TREE_CHANGED)
6103 ret = process_changed_xattr(sctx);
6106 return ret;
6110 * Process new/deleted/changed extents. We skip processing in the
6111 * cur_inode_new_gen case because changed_inode did already initiate processing
6112 * of extents. The reason is the same as in changed_ref
6114 static int changed_extent(struct send_ctx *sctx,
6115 enum btrfs_compare_tree_result result)
6117 int ret = 0;
6119 if (sctx->cur_ino != sctx->cmp_key->objectid) {
6121 if (result == BTRFS_COMPARE_TREE_CHANGED) {
6122 struct extent_buffer *leaf_l;
6123 struct extent_buffer *leaf_r;
6124 struct btrfs_file_extent_item *ei_l;
6125 struct btrfs_file_extent_item *ei_r;
6127 leaf_l = sctx->left_path->nodes[0];
6128 leaf_r = sctx->right_path->nodes[0];
6129 ei_l = btrfs_item_ptr(leaf_l,
6130 sctx->left_path->slots[0],
6131 struct btrfs_file_extent_item);
6132 ei_r = btrfs_item_ptr(leaf_r,
6133 sctx->right_path->slots[0],
6134 struct btrfs_file_extent_item);
6137 * We may have found an extent item that has changed
6138 * only its disk_bytenr field and the corresponding
6139 * inode item was not updated. This case happens due to
6140 * very specific timings during relocation when a leaf
6141 * that contains file extent items is COWed while
6142 * relocation is ongoing and its in the stage where it
6143 * updates data pointers. So when this happens we can
6144 * safely ignore it since we know it's the same extent,
6145 * but just at different logical and physical locations
6146 * (when an extent is fully replaced with a new one, we
6147 * know the generation number must have changed too,
6148 * since snapshot creation implies committing the current
6149 * transaction, and the inode item must have been updated
6150 * as well).
6151 * This replacement of the disk_bytenr happens at
6152 * relocation.c:replace_file_extents() through
6153 * relocation.c:btrfs_reloc_cow_block().
6155 if (btrfs_file_extent_generation(leaf_l, ei_l) ==
6156 btrfs_file_extent_generation(leaf_r, ei_r) &&
6157 btrfs_file_extent_ram_bytes(leaf_l, ei_l) ==
6158 btrfs_file_extent_ram_bytes(leaf_r, ei_r) &&
6159 btrfs_file_extent_compression(leaf_l, ei_l) ==
6160 btrfs_file_extent_compression(leaf_r, ei_r) &&
6161 btrfs_file_extent_encryption(leaf_l, ei_l) ==
6162 btrfs_file_extent_encryption(leaf_r, ei_r) &&
6163 btrfs_file_extent_other_encoding(leaf_l, ei_l) ==
6164 btrfs_file_extent_other_encoding(leaf_r, ei_r) &&
6165 btrfs_file_extent_type(leaf_l, ei_l) ==
6166 btrfs_file_extent_type(leaf_r, ei_r) &&
6167 btrfs_file_extent_disk_bytenr(leaf_l, ei_l) !=
6168 btrfs_file_extent_disk_bytenr(leaf_r, ei_r) &&
6169 btrfs_file_extent_disk_num_bytes(leaf_l, ei_l) ==
6170 btrfs_file_extent_disk_num_bytes(leaf_r, ei_r) &&
6171 btrfs_file_extent_offset(leaf_l, ei_l) ==
6172 btrfs_file_extent_offset(leaf_r, ei_r) &&
6173 btrfs_file_extent_num_bytes(leaf_l, ei_l) ==
6174 btrfs_file_extent_num_bytes(leaf_r, ei_r))
6175 return 0;
6178 inconsistent_snapshot_error(sctx, result, "extent");
6179 return -EIO;
6182 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
6183 if (result != BTRFS_COMPARE_TREE_DELETED)
6184 ret = process_extent(sctx, sctx->left_path,
6185 sctx->cmp_key);
6188 return ret;
6191 static int dir_changed(struct send_ctx *sctx, u64 dir)
6193 u64 orig_gen, new_gen;
6194 int ret;
6196 ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
6197 NULL, NULL);
6198 if (ret)
6199 return ret;
6201 ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
6202 NULL, NULL, NULL);
6203 if (ret)
6204 return ret;
6206 return (orig_gen != new_gen) ? 1 : 0;
6209 static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path,
6210 struct btrfs_key *key)
6212 struct btrfs_inode_extref *extref;
6213 struct extent_buffer *leaf;
6214 u64 dirid = 0, last_dirid = 0;
6215 unsigned long ptr;
6216 u32 item_size;
6217 u32 cur_offset = 0;
6218 int ref_name_len;
6219 int ret = 0;
6221 /* Easy case, just check this one dirid */
6222 if (key->type == BTRFS_INODE_REF_KEY) {
6223 dirid = key->offset;
6225 ret = dir_changed(sctx, dirid);
6226 goto out;
6229 leaf = path->nodes[0];
6230 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
6231 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
6232 while (cur_offset < item_size) {
6233 extref = (struct btrfs_inode_extref *)(ptr +
6234 cur_offset);
6235 dirid = btrfs_inode_extref_parent(leaf, extref);
6236 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
6237 cur_offset += ref_name_len + sizeof(*extref);
6238 if (dirid == last_dirid)
6239 continue;
6240 ret = dir_changed(sctx, dirid);
6241 if (ret)
6242 break;
6243 last_dirid = dirid;
6245 out:
6246 return ret;
6250 * Updates compare related fields in sctx and simply forwards to the actual
6251 * changed_xxx functions.
6253 static int changed_cb(struct btrfs_path *left_path,
6254 struct btrfs_path *right_path,
6255 struct btrfs_key *key,
6256 enum btrfs_compare_tree_result result,
6257 void *ctx)
6259 int ret = 0;
6260 struct send_ctx *sctx = ctx;
6262 if (result == BTRFS_COMPARE_TREE_SAME) {
6263 if (key->type == BTRFS_INODE_REF_KEY ||
6264 key->type == BTRFS_INODE_EXTREF_KEY) {
6265 ret = compare_refs(sctx, left_path, key);
6266 if (!ret)
6267 return 0;
6268 if (ret < 0)
6269 return ret;
6270 } else if (key->type == BTRFS_EXTENT_DATA_KEY) {
6271 return maybe_send_hole(sctx, left_path, key);
6272 } else {
6273 return 0;
6275 result = BTRFS_COMPARE_TREE_CHANGED;
6276 ret = 0;
6279 sctx->left_path = left_path;
6280 sctx->right_path = right_path;
6281 sctx->cmp_key = key;
6283 ret = finish_inode_if_needed(sctx, 0);
6284 if (ret < 0)
6285 goto out;
6287 /* Ignore non-FS objects */
6288 if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
6289 key->objectid == BTRFS_FREE_SPACE_OBJECTID)
6290 goto out;
6292 if (key->type == BTRFS_INODE_ITEM_KEY)
6293 ret = changed_inode(sctx, result);
6294 else if (key->type == BTRFS_INODE_REF_KEY ||
6295 key->type == BTRFS_INODE_EXTREF_KEY)
6296 ret = changed_ref(sctx, result);
6297 else if (key->type == BTRFS_XATTR_ITEM_KEY)
6298 ret = changed_xattr(sctx, result);
6299 else if (key->type == BTRFS_EXTENT_DATA_KEY)
6300 ret = changed_extent(sctx, result);
6302 out:
6303 return ret;
6306 static int full_send_tree(struct send_ctx *sctx)
6308 int ret;
6309 struct btrfs_root *send_root = sctx->send_root;
6310 struct btrfs_key key;
6311 struct btrfs_key found_key;
6312 struct btrfs_path *path;
6313 struct extent_buffer *eb;
6314 int slot;
6316 path = alloc_path_for_send();
6317 if (!path)
6318 return -ENOMEM;
6320 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
6321 key.type = BTRFS_INODE_ITEM_KEY;
6322 key.offset = 0;
6324 ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
6325 if (ret < 0)
6326 goto out;
6327 if (ret)
6328 goto out_finish;
6330 while (1) {
6331 eb = path->nodes[0];
6332 slot = path->slots[0];
6333 btrfs_item_key_to_cpu(eb, &found_key, slot);
6335 ret = changed_cb(path, NULL, &found_key,
6336 BTRFS_COMPARE_TREE_NEW, sctx);
6337 if (ret < 0)
6338 goto out;
6340 key.objectid = found_key.objectid;
6341 key.type = found_key.type;
6342 key.offset = found_key.offset + 1;
6344 ret = btrfs_next_item(send_root, path);
6345 if (ret < 0)
6346 goto out;
6347 if (ret) {
6348 ret = 0;
6349 break;
6353 out_finish:
6354 ret = finish_inode_if_needed(sctx, 1);
6356 out:
6357 btrfs_free_path(path);
6358 return ret;
6361 static int send_subvol(struct send_ctx *sctx)
6363 int ret;
6365 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
6366 ret = send_header(sctx);
6367 if (ret < 0)
6368 goto out;
6371 ret = send_subvol_begin(sctx);
6372 if (ret < 0)
6373 goto out;
6375 if (sctx->parent_root) {
6376 ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
6377 changed_cb, sctx);
6378 if (ret < 0)
6379 goto out;
6380 ret = finish_inode_if_needed(sctx, 1);
6381 if (ret < 0)
6382 goto out;
6383 } else {
6384 ret = full_send_tree(sctx);
6385 if (ret < 0)
6386 goto out;
6389 out:
6390 free_recorded_refs(sctx);
6391 return ret;
6395 * If orphan cleanup did remove any orphans from a root, it means the tree
6396 * was modified and therefore the commit root is not the same as the current
6397 * root anymore. This is a problem, because send uses the commit root and
6398 * therefore can see inode items that don't exist in the current root anymore,
6399 * and for example make calls to btrfs_iget, which will do tree lookups based
6400 * on the current root and not on the commit root. Those lookups will fail,
6401 * returning a -ESTALE error, and making send fail with that error. So make
6402 * sure a send does not see any orphans we have just removed, and that it will
6403 * see the same inodes regardless of whether a transaction commit happened
6404 * before it started (meaning that the commit root will be the same as the
6405 * current root) or not.
6407 static int ensure_commit_roots_uptodate(struct send_ctx *sctx)
6409 int i;
6410 struct btrfs_trans_handle *trans = NULL;
6412 again:
6413 if (sctx->parent_root &&
6414 sctx->parent_root->node != sctx->parent_root->commit_root)
6415 goto commit_trans;
6417 for (i = 0; i < sctx->clone_roots_cnt; i++)
6418 if (sctx->clone_roots[i].root->node !=
6419 sctx->clone_roots[i].root->commit_root)
6420 goto commit_trans;
6422 if (trans)
6423 return btrfs_end_transaction(trans);
6425 return 0;
6427 commit_trans:
6428 /* Use any root, all fs roots will get their commit roots updated. */
6429 if (!trans) {
6430 trans = btrfs_join_transaction(sctx->send_root);
6431 if (IS_ERR(trans))
6432 return PTR_ERR(trans);
6433 goto again;
6436 return btrfs_commit_transaction(trans);
6439 static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
6441 spin_lock(&root->root_item_lock);
6442 root->send_in_progress--;
6444 * Not much left to do, we don't know why it's unbalanced and
6445 * can't blindly reset it to 0.
6447 if (root->send_in_progress < 0)
6448 btrfs_err(root->fs_info,
6449 "send_in_progres unbalanced %d root %llu",
6450 root->send_in_progress, root->root_key.objectid);
6451 spin_unlock(&root->root_item_lock);
6454 long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
6456 int ret = 0;
6457 struct btrfs_root *send_root = BTRFS_I(file_inode(mnt_file))->root;
6458 struct btrfs_fs_info *fs_info = send_root->fs_info;
6459 struct btrfs_root *clone_root;
6460 struct btrfs_key key;
6461 struct send_ctx *sctx = NULL;
6462 u32 i;
6463 u64 *clone_sources_tmp = NULL;
6464 int clone_sources_to_rollback = 0;
6465 unsigned alloc_size;
6466 int sort_clone_roots = 0;
6467 int index;
6469 if (!capable(CAP_SYS_ADMIN))
6470 return -EPERM;
6473 * The subvolume must remain read-only during send, protect against
6474 * making it RW. This also protects against deletion.
6476 spin_lock(&send_root->root_item_lock);
6477 send_root->send_in_progress++;
6478 spin_unlock(&send_root->root_item_lock);
6481 * This is done when we lookup the root, it should already be complete
6482 * by the time we get here.
6484 WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE);
6487 * Userspace tools do the checks and warn the user if it's
6488 * not RO.
6490 if (!btrfs_root_readonly(send_root)) {
6491 ret = -EPERM;
6492 goto out;
6496 * Check that we don't overflow at later allocations, we request
6497 * clone_sources_count + 1 items, and compare to unsigned long inside
6498 * access_ok.
6500 if (arg->clone_sources_count >
6501 ULONG_MAX / sizeof(struct clone_root) - 1) {
6502 ret = -EINVAL;
6503 goto out;
6506 if (!access_ok(VERIFY_READ, arg->clone_sources,
6507 sizeof(*arg->clone_sources) *
6508 arg->clone_sources_count)) {
6509 ret = -EFAULT;
6510 goto out;
6513 if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
6514 ret = -EINVAL;
6515 goto out;
6518 sctx = kzalloc(sizeof(struct send_ctx), GFP_KERNEL);
6519 if (!sctx) {
6520 ret = -ENOMEM;
6521 goto out;
6524 INIT_LIST_HEAD(&sctx->new_refs);
6525 INIT_LIST_HEAD(&sctx->deleted_refs);
6526 INIT_RADIX_TREE(&sctx->name_cache, GFP_KERNEL);
6527 INIT_LIST_HEAD(&sctx->name_cache_list);
6529 sctx->flags = arg->flags;
6531 sctx->send_filp = fget(arg->send_fd);
6532 if (!sctx->send_filp) {
6533 ret = -EBADF;
6534 goto out;
6537 sctx->send_root = send_root;
6539 * Unlikely but possible, if the subvolume is marked for deletion but
6540 * is slow to remove the directory entry, send can still be started
6542 if (btrfs_root_dead(sctx->send_root)) {
6543 ret = -EPERM;
6544 goto out;
6547 sctx->clone_roots_cnt = arg->clone_sources_count;
6549 sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
6550 sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
6551 if (!sctx->send_buf) {
6552 ret = -ENOMEM;
6553 goto out;
6556 sctx->read_buf = kvmalloc(BTRFS_SEND_READ_SIZE, GFP_KERNEL);
6557 if (!sctx->read_buf) {
6558 ret = -ENOMEM;
6559 goto out;
6562 sctx->pending_dir_moves = RB_ROOT;
6563 sctx->waiting_dir_moves = RB_ROOT;
6564 sctx->orphan_dirs = RB_ROOT;
6566 alloc_size = sizeof(struct clone_root) * (arg->clone_sources_count + 1);
6568 sctx->clone_roots = kzalloc(alloc_size, GFP_KERNEL);
6569 if (!sctx->clone_roots) {
6570 ret = -ENOMEM;
6571 goto out;
6574 alloc_size = arg->clone_sources_count * sizeof(*arg->clone_sources);
6576 if (arg->clone_sources_count) {
6577 clone_sources_tmp = kvmalloc(alloc_size, GFP_KERNEL);
6578 if (!clone_sources_tmp) {
6579 ret = -ENOMEM;
6580 goto out;
6583 ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
6584 alloc_size);
6585 if (ret) {
6586 ret = -EFAULT;
6587 goto out;
6590 for (i = 0; i < arg->clone_sources_count; i++) {
6591 key.objectid = clone_sources_tmp[i];
6592 key.type = BTRFS_ROOT_ITEM_KEY;
6593 key.offset = (u64)-1;
6595 index = srcu_read_lock(&fs_info->subvol_srcu);
6597 clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
6598 if (IS_ERR(clone_root)) {
6599 srcu_read_unlock(&fs_info->subvol_srcu, index);
6600 ret = PTR_ERR(clone_root);
6601 goto out;
6603 spin_lock(&clone_root->root_item_lock);
6604 if (!btrfs_root_readonly(clone_root) ||
6605 btrfs_root_dead(clone_root)) {
6606 spin_unlock(&clone_root->root_item_lock);
6607 srcu_read_unlock(&fs_info->subvol_srcu, index);
6608 ret = -EPERM;
6609 goto out;
6611 clone_root->send_in_progress++;
6612 spin_unlock(&clone_root->root_item_lock);
6613 srcu_read_unlock(&fs_info->subvol_srcu, index);
6615 sctx->clone_roots[i].root = clone_root;
6616 clone_sources_to_rollback = i + 1;
6618 kvfree(clone_sources_tmp);
6619 clone_sources_tmp = NULL;
6622 if (arg->parent_root) {
6623 key.objectid = arg->parent_root;
6624 key.type = BTRFS_ROOT_ITEM_KEY;
6625 key.offset = (u64)-1;
6627 index = srcu_read_lock(&fs_info->subvol_srcu);
6629 sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
6630 if (IS_ERR(sctx->parent_root)) {
6631 srcu_read_unlock(&fs_info->subvol_srcu, index);
6632 ret = PTR_ERR(sctx->parent_root);
6633 goto out;
6636 spin_lock(&sctx->parent_root->root_item_lock);
6637 sctx->parent_root->send_in_progress++;
6638 if (!btrfs_root_readonly(sctx->parent_root) ||
6639 btrfs_root_dead(sctx->parent_root)) {
6640 spin_unlock(&sctx->parent_root->root_item_lock);
6641 srcu_read_unlock(&fs_info->subvol_srcu, index);
6642 ret = -EPERM;
6643 goto out;
6645 spin_unlock(&sctx->parent_root->root_item_lock);
6647 srcu_read_unlock(&fs_info->subvol_srcu, index);
6651 * Clones from send_root are allowed, but only if the clone source
6652 * is behind the current send position. This is checked while searching
6653 * for possible clone sources.
6655 sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;
6657 /* We do a bsearch later */
6658 sort(sctx->clone_roots, sctx->clone_roots_cnt,
6659 sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
6660 NULL);
6661 sort_clone_roots = 1;
6663 ret = ensure_commit_roots_uptodate(sctx);
6664 if (ret)
6665 goto out;
6667 current->journal_info = BTRFS_SEND_TRANS_STUB;
6668 ret = send_subvol(sctx);
6669 current->journal_info = NULL;
6670 if (ret < 0)
6671 goto out;
6673 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) {
6674 ret = begin_cmd(sctx, BTRFS_SEND_C_END);
6675 if (ret < 0)
6676 goto out;
6677 ret = send_cmd(sctx);
6678 if (ret < 0)
6679 goto out;
6682 out:
6683 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
6684 while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
6685 struct rb_node *n;
6686 struct pending_dir_move *pm;
6688 n = rb_first(&sctx->pending_dir_moves);
6689 pm = rb_entry(n, struct pending_dir_move, node);
6690 while (!list_empty(&pm->list)) {
6691 struct pending_dir_move *pm2;
6693 pm2 = list_first_entry(&pm->list,
6694 struct pending_dir_move, list);
6695 free_pending_move(sctx, pm2);
6697 free_pending_move(sctx, pm);
6700 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
6701 while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
6702 struct rb_node *n;
6703 struct waiting_dir_move *dm;
6705 n = rb_first(&sctx->waiting_dir_moves);
6706 dm = rb_entry(n, struct waiting_dir_move, node);
6707 rb_erase(&dm->node, &sctx->waiting_dir_moves);
6708 kfree(dm);
6711 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->orphan_dirs));
6712 while (sctx && !RB_EMPTY_ROOT(&sctx->orphan_dirs)) {
6713 struct rb_node *n;
6714 struct orphan_dir_info *odi;
6716 n = rb_first(&sctx->orphan_dirs);
6717 odi = rb_entry(n, struct orphan_dir_info, node);
6718 free_orphan_dir_info(sctx, odi);
6721 if (sort_clone_roots) {
6722 for (i = 0; i < sctx->clone_roots_cnt; i++)
6723 btrfs_root_dec_send_in_progress(
6724 sctx->clone_roots[i].root);
6725 } else {
6726 for (i = 0; sctx && i < clone_sources_to_rollback; i++)
6727 btrfs_root_dec_send_in_progress(
6728 sctx->clone_roots[i].root);
6730 btrfs_root_dec_send_in_progress(send_root);
6732 if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
6733 btrfs_root_dec_send_in_progress(sctx->parent_root);
6735 kvfree(clone_sources_tmp);
6737 if (sctx) {
6738 if (sctx->send_filp)
6739 fput(sctx->send_filp);
6741 kvfree(sctx->clone_roots);
6742 kvfree(sctx->send_buf);
6743 kvfree(sctx->read_buf);
6745 name_cache_free(sctx);
6747 kfree(sctx);
6750 return ret;