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>
21 #include <linux/file.h>
22 #include <linux/sort.h>
23 #include <linux/mount.h>
24 #include <linux/xattr.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/radix-tree.h>
27 #include <linux/crc32c.h>
28 #include <linux/vmalloc.h>
29 #include <linux/string.h>
35 #include "btrfs_inode.h"
36 #include "transaction.h"
38 static int g_verbose
= 0;
40 #define verbose_printk(...) if (g_verbose) printk(__VA_ARGS__)
43 * A fs_path is a helper to dynamically build path names with unknown size.
44 * It reallocates the internal buffer on demand.
45 * It allows fast adding of path elements on the right side (normal path) and
46 * fast adding to the left side (reversed path). A reversed path can also be
47 * unreversed if needed.
58 unsigned int reversed
:1;
59 unsigned int virtual_mem
:1;
65 #define FS_PATH_INLINE_SIZE \
66 (sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
69 /* reused for each extent */
71 struct btrfs_root
*root
;
78 #define SEND_CTX_MAX_NAME_CACHE_SIZE 128
79 #define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
82 struct file
*send_filp
;
88 u64 cmd_send_size
[BTRFS_SEND_C_MAX
+ 1];
89 u64 flags
; /* 'flags' member of btrfs_ioctl_send_args is u64 */
91 struct btrfs_root
*send_root
;
92 struct btrfs_root
*parent_root
;
93 struct clone_root
*clone_roots
;
96 /* current state of the compare_tree call */
97 struct btrfs_path
*left_path
;
98 struct btrfs_path
*right_path
;
99 struct btrfs_key
*cmp_key
;
102 * infos of the currently processed inode. In case of deleted inodes,
103 * these are the values from the deleted inode.
108 int cur_inode_new_gen
;
109 int cur_inode_deleted
;
112 u64 cur_inode_last_extent
;
116 struct list_head new_refs
;
117 struct list_head deleted_refs
;
119 struct radix_tree_root name_cache
;
120 struct list_head name_cache_list
;
126 struct name_cache_entry
{
127 struct list_head list
;
129 * radix_tree has only 32bit entries but we need to handle 64bit inums.
130 * We use the lower 32bit of the 64bit inum to store it in the tree. If
131 * more then one inum would fall into the same entry, we use radix_list
132 * to store the additional entries. radix_list is also used to store
133 * entries where two entries have the same inum but different
136 struct list_head radix_list
;
142 int need_later_update
;
147 static int need_send_hole(struct send_ctx
*sctx
)
149 return (sctx
->parent_root
&& !sctx
->cur_inode_new
&&
150 !sctx
->cur_inode_new_gen
&& !sctx
->cur_inode_deleted
&&
151 S_ISREG(sctx
->cur_inode_mode
));
154 static void fs_path_reset(struct fs_path
*p
)
157 p
->start
= p
->buf
+ p
->buf_len
- 1;
167 static struct fs_path
*fs_path_alloc(void)
171 p
= kmalloc(sizeof(*p
), GFP_NOFS
);
176 p
->buf
= p
->inline_buf
;
177 p
->buf_len
= FS_PATH_INLINE_SIZE
;
182 static struct fs_path
*fs_path_alloc_reversed(void)
194 static void fs_path_free(struct fs_path
*p
)
198 if (p
->buf
!= p
->inline_buf
) {
207 static int fs_path_len(struct fs_path
*p
)
209 return p
->end
- p
->start
;
212 static int fs_path_ensure_buf(struct fs_path
*p
, int len
)
220 if (p
->buf_len
>= len
)
223 path_len
= p
->end
- p
->start
;
224 old_buf_len
= p
->buf_len
;
225 len
= PAGE_ALIGN(len
);
227 if (p
->buf
== p
->inline_buf
) {
228 tmp_buf
= kmalloc(len
, GFP_NOFS
| __GFP_NOWARN
);
230 tmp_buf
= vmalloc(len
);
235 memcpy(tmp_buf
, p
->buf
, p
->buf_len
);
239 if (p
->virtual_mem
) {
240 tmp_buf
= vmalloc(len
);
243 memcpy(tmp_buf
, p
->buf
, p
->buf_len
);
246 tmp_buf
= krealloc(p
->buf
, len
, GFP_NOFS
);
248 tmp_buf
= vmalloc(len
);
251 memcpy(tmp_buf
, p
->buf
, p
->buf_len
);
260 tmp_buf
= p
->buf
+ old_buf_len
- path_len
- 1;
261 p
->end
= p
->buf
+ p
->buf_len
- 1;
262 p
->start
= p
->end
- path_len
;
263 memmove(p
->start
, tmp_buf
, path_len
+ 1);
266 p
->end
= p
->start
+ path_len
;
271 static int fs_path_prepare_for_add(struct fs_path
*p
, int name_len
)
276 new_len
= p
->end
- p
->start
+ name_len
;
277 if (p
->start
!= p
->end
)
279 ret
= fs_path_ensure_buf(p
, new_len
);
284 if (p
->start
!= p
->end
)
286 p
->start
-= name_len
;
287 p
->prepared
= p
->start
;
289 if (p
->start
!= p
->end
)
291 p
->prepared
= p
->end
;
300 static int fs_path_add(struct fs_path
*p
, const char *name
, int name_len
)
304 ret
= fs_path_prepare_for_add(p
, name_len
);
307 memcpy(p
->prepared
, name
, name_len
);
314 static int fs_path_add_path(struct fs_path
*p
, struct fs_path
*p2
)
318 ret
= fs_path_prepare_for_add(p
, p2
->end
- p2
->start
);
321 memcpy(p
->prepared
, p2
->start
, p2
->end
- p2
->start
);
328 static int fs_path_add_from_extent_buffer(struct fs_path
*p
,
329 struct extent_buffer
*eb
,
330 unsigned long off
, int len
)
334 ret
= fs_path_prepare_for_add(p
, len
);
338 read_extent_buffer(eb
, p
->prepared
, off
, len
);
345 static int fs_path_copy(struct fs_path
*p
, struct fs_path
*from
)
349 p
->reversed
= from
->reversed
;
352 ret
= fs_path_add_path(p
, from
);
358 static void fs_path_unreverse(struct fs_path
*p
)
367 len
= p
->end
- p
->start
;
369 p
->end
= p
->start
+ len
;
370 memmove(p
->start
, tmp
, len
+ 1);
374 static struct btrfs_path
*alloc_path_for_send(void)
376 struct btrfs_path
*path
;
378 path
= btrfs_alloc_path();
381 path
->search_commit_root
= 1;
382 path
->skip_locking
= 1;
386 static int write_buf(struct file
*filp
, const void *buf
, u32 len
, loff_t
*off
)
396 ret
= vfs_write(filp
, (char *)buf
+ pos
, len
- pos
, off
);
397 /* TODO handle that correctly */
398 /*if (ret == -ERESTARTSYS) {
417 static int tlv_put(struct send_ctx
*sctx
, u16 attr
, const void *data
, int len
)
419 struct btrfs_tlv_header
*hdr
;
420 int total_len
= sizeof(*hdr
) + len
;
421 int left
= sctx
->send_max_size
- sctx
->send_size
;
423 if (unlikely(left
< total_len
))
426 hdr
= (struct btrfs_tlv_header
*) (sctx
->send_buf
+ sctx
->send_size
);
427 hdr
->tlv_type
= cpu_to_le16(attr
);
428 hdr
->tlv_len
= cpu_to_le16(len
);
429 memcpy(hdr
+ 1, data
, len
);
430 sctx
->send_size
+= total_len
;
435 #define TLV_PUT_DEFINE_INT(bits) \
436 static int tlv_put_u##bits(struct send_ctx *sctx, \
437 u##bits attr, u##bits value) \
439 __le##bits __tmp = cpu_to_le##bits(value); \
440 return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \
443 TLV_PUT_DEFINE_INT(64)
445 static int tlv_put_string(struct send_ctx
*sctx
, u16 attr
,
446 const char *str
, int len
)
450 return tlv_put(sctx
, attr
, str
, len
);
453 static int tlv_put_uuid(struct send_ctx
*sctx
, u16 attr
,
456 return tlv_put(sctx
, attr
, uuid
, BTRFS_UUID_SIZE
);
459 static int tlv_put_btrfs_timespec(struct send_ctx
*sctx
, u16 attr
,
460 struct extent_buffer
*eb
,
461 struct btrfs_timespec
*ts
)
463 struct btrfs_timespec bts
;
464 read_extent_buffer(eb
, &bts
, (unsigned long)ts
, sizeof(bts
));
465 return tlv_put(sctx
, attr
, &bts
, sizeof(bts
));
469 #define TLV_PUT(sctx, attrtype, attrlen, data) \
471 ret = tlv_put(sctx, attrtype, attrlen, data); \
473 goto tlv_put_failure; \
476 #define TLV_PUT_INT(sctx, attrtype, bits, value) \
478 ret = tlv_put_u##bits(sctx, attrtype, value); \
480 goto tlv_put_failure; \
483 #define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
484 #define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
485 #define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
486 #define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
487 #define TLV_PUT_STRING(sctx, attrtype, str, len) \
489 ret = tlv_put_string(sctx, attrtype, str, len); \
491 goto tlv_put_failure; \
493 #define TLV_PUT_PATH(sctx, attrtype, p) \
495 ret = tlv_put_string(sctx, attrtype, p->start, \
496 p->end - p->start); \
498 goto tlv_put_failure; \
500 #define TLV_PUT_UUID(sctx, attrtype, uuid) \
502 ret = tlv_put_uuid(sctx, attrtype, uuid); \
504 goto tlv_put_failure; \
506 #define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
508 ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
510 goto tlv_put_failure; \
513 static int send_header(struct send_ctx
*sctx
)
515 struct btrfs_stream_header hdr
;
517 strcpy(hdr
.magic
, BTRFS_SEND_STREAM_MAGIC
);
518 hdr
.version
= cpu_to_le32(BTRFS_SEND_STREAM_VERSION
);
520 return write_buf(sctx
->send_filp
, &hdr
, sizeof(hdr
),
525 * For each command/item we want to send to userspace, we call this function.
527 static int begin_cmd(struct send_ctx
*sctx
, int cmd
)
529 struct btrfs_cmd_header
*hdr
;
531 if (WARN_ON(!sctx
->send_buf
))
534 BUG_ON(sctx
->send_size
);
536 sctx
->send_size
+= sizeof(*hdr
);
537 hdr
= (struct btrfs_cmd_header
*)sctx
->send_buf
;
538 hdr
->cmd
= cpu_to_le16(cmd
);
543 static int send_cmd(struct send_ctx
*sctx
)
546 struct btrfs_cmd_header
*hdr
;
549 hdr
= (struct btrfs_cmd_header
*)sctx
->send_buf
;
550 hdr
->len
= cpu_to_le32(sctx
->send_size
- sizeof(*hdr
));
553 crc
= crc32c(0, (unsigned char *)sctx
->send_buf
, sctx
->send_size
);
554 hdr
->crc
= cpu_to_le32(crc
);
556 ret
= write_buf(sctx
->send_filp
, sctx
->send_buf
, sctx
->send_size
,
559 sctx
->total_send_size
+= sctx
->send_size
;
560 sctx
->cmd_send_size
[le16_to_cpu(hdr
->cmd
)] += sctx
->send_size
;
567 * Sends a move instruction to user space
569 static int send_rename(struct send_ctx
*sctx
,
570 struct fs_path
*from
, struct fs_path
*to
)
574 verbose_printk("btrfs: send_rename %s -> %s\n", from
->start
, to
->start
);
576 ret
= begin_cmd(sctx
, BTRFS_SEND_C_RENAME
);
580 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, from
);
581 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH_TO
, to
);
583 ret
= send_cmd(sctx
);
591 * Sends a link instruction to user space
593 static int send_link(struct send_ctx
*sctx
,
594 struct fs_path
*path
, struct fs_path
*lnk
)
598 verbose_printk("btrfs: send_link %s -> %s\n", path
->start
, lnk
->start
);
600 ret
= begin_cmd(sctx
, BTRFS_SEND_C_LINK
);
604 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, path
);
605 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH_LINK
, lnk
);
607 ret
= send_cmd(sctx
);
615 * Sends an unlink instruction to user space
617 static int send_unlink(struct send_ctx
*sctx
, struct fs_path
*path
)
621 verbose_printk("btrfs: send_unlink %s\n", path
->start
);
623 ret
= begin_cmd(sctx
, BTRFS_SEND_C_UNLINK
);
627 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, path
);
629 ret
= send_cmd(sctx
);
637 * Sends a rmdir instruction to user space
639 static int send_rmdir(struct send_ctx
*sctx
, struct fs_path
*path
)
643 verbose_printk("btrfs: send_rmdir %s\n", path
->start
);
645 ret
= begin_cmd(sctx
, BTRFS_SEND_C_RMDIR
);
649 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, path
);
651 ret
= send_cmd(sctx
);
659 * Helper function to retrieve some fields from an inode item.
661 static int get_inode_info(struct btrfs_root
*root
,
662 u64 ino
, u64
*size
, u64
*gen
,
663 u64
*mode
, u64
*uid
, u64
*gid
,
667 struct btrfs_inode_item
*ii
;
668 struct btrfs_key key
;
669 struct btrfs_path
*path
;
671 path
= alloc_path_for_send();
676 key
.type
= BTRFS_INODE_ITEM_KEY
;
678 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
686 ii
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
687 struct btrfs_inode_item
);
689 *size
= btrfs_inode_size(path
->nodes
[0], ii
);
691 *gen
= btrfs_inode_generation(path
->nodes
[0], ii
);
693 *mode
= btrfs_inode_mode(path
->nodes
[0], ii
);
695 *uid
= btrfs_inode_uid(path
->nodes
[0], ii
);
697 *gid
= btrfs_inode_gid(path
->nodes
[0], ii
);
699 *rdev
= btrfs_inode_rdev(path
->nodes
[0], ii
);
702 btrfs_free_path(path
);
706 typedef int (*iterate_inode_ref_t
)(int num
, u64 dir
, int index
,
711 * Helper function to iterate the entries in ONE btrfs_inode_ref or
712 * btrfs_inode_extref.
713 * The iterate callback may return a non zero value to stop iteration. This can
714 * be a negative value for error codes or 1 to simply stop it.
716 * path must point to the INODE_REF or INODE_EXTREF when called.
718 static int iterate_inode_ref(struct btrfs_root
*root
, struct btrfs_path
*path
,
719 struct btrfs_key
*found_key
, int resolve
,
720 iterate_inode_ref_t iterate
, void *ctx
)
722 struct extent_buffer
*eb
= path
->nodes
[0];
723 struct btrfs_item
*item
;
724 struct btrfs_inode_ref
*iref
;
725 struct btrfs_inode_extref
*extref
;
726 struct btrfs_path
*tmp_path
;
730 int slot
= path
->slots
[0];
737 unsigned long name_off
;
738 unsigned long elem_size
;
741 p
= fs_path_alloc_reversed();
745 tmp_path
= alloc_path_for_send();
752 if (found_key
->type
== BTRFS_INODE_REF_KEY
) {
753 ptr
= (unsigned long)btrfs_item_ptr(eb
, slot
,
754 struct btrfs_inode_ref
);
755 item
= btrfs_item_nr(slot
);
756 total
= btrfs_item_size(eb
, item
);
757 elem_size
= sizeof(*iref
);
759 ptr
= btrfs_item_ptr_offset(eb
, slot
);
760 total
= btrfs_item_size_nr(eb
, slot
);
761 elem_size
= sizeof(*extref
);
764 while (cur
< total
) {
767 if (found_key
->type
== BTRFS_INODE_REF_KEY
) {
768 iref
= (struct btrfs_inode_ref
*)(ptr
+ cur
);
769 name_len
= btrfs_inode_ref_name_len(eb
, iref
);
770 name_off
= (unsigned long)(iref
+ 1);
771 index
= btrfs_inode_ref_index(eb
, iref
);
772 dir
= found_key
->offset
;
774 extref
= (struct btrfs_inode_extref
*)(ptr
+ cur
);
775 name_len
= btrfs_inode_extref_name_len(eb
, extref
);
776 name_off
= (unsigned long)&extref
->name
;
777 index
= btrfs_inode_extref_index(eb
, extref
);
778 dir
= btrfs_inode_extref_parent(eb
, extref
);
782 start
= btrfs_ref_to_path(root
, tmp_path
, name_len
,
786 ret
= PTR_ERR(start
);
789 if (start
< p
->buf
) {
790 /* overflow , try again with larger buffer */
791 ret
= fs_path_ensure_buf(p
,
792 p
->buf_len
+ p
->buf
- start
);
795 start
= btrfs_ref_to_path(root
, tmp_path
,
800 ret
= PTR_ERR(start
);
803 BUG_ON(start
< p
->buf
);
807 ret
= fs_path_add_from_extent_buffer(p
, eb
, name_off
,
813 cur
+= elem_size
+ name_len
;
814 ret
= iterate(num
, dir
, index
, p
, ctx
);
821 btrfs_free_path(tmp_path
);
826 typedef int (*iterate_dir_item_t
)(int num
, struct btrfs_key
*di_key
,
827 const char *name
, int name_len
,
828 const char *data
, int data_len
,
832 * Helper function to iterate the entries in ONE btrfs_dir_item.
833 * The iterate callback may return a non zero value to stop iteration. This can
834 * be a negative value for error codes or 1 to simply stop it.
836 * path must point to the dir item when called.
838 static int iterate_dir_item(struct btrfs_root
*root
, struct btrfs_path
*path
,
839 struct btrfs_key
*found_key
,
840 iterate_dir_item_t iterate
, void *ctx
)
843 struct extent_buffer
*eb
;
844 struct btrfs_item
*item
;
845 struct btrfs_dir_item
*di
;
846 struct btrfs_key di_key
;
861 buf
= kmalloc(buf_len
, GFP_NOFS
);
868 slot
= path
->slots
[0];
869 item
= btrfs_item_nr(slot
);
870 di
= btrfs_item_ptr(eb
, slot
, struct btrfs_dir_item
);
873 total
= btrfs_item_size(eb
, item
);
876 while (cur
< total
) {
877 name_len
= btrfs_dir_name_len(eb
, di
);
878 data_len
= btrfs_dir_data_len(eb
, di
);
879 type
= btrfs_dir_type(eb
, di
);
880 btrfs_dir_item_key_to_cpu(eb
, di
, &di_key
);
882 if (name_len
+ data_len
> buf_len
) {
883 buf_len
= PAGE_ALIGN(name_len
+ data_len
);
885 buf2
= vmalloc(buf_len
);
892 buf2
= krealloc(buf
, buf_len
, GFP_NOFS
);
894 buf2
= vmalloc(buf_len
);
908 read_extent_buffer(eb
, buf
, (unsigned long)(di
+ 1),
909 name_len
+ data_len
);
911 len
= sizeof(*di
) + name_len
+ data_len
;
912 di
= (struct btrfs_dir_item
*)((char *)di
+ len
);
915 ret
= iterate(num
, &di_key
, buf
, name_len
, buf
+ name_len
,
916 data_len
, type
, ctx
);
935 static int __copy_first_ref(int num
, u64 dir
, int index
,
936 struct fs_path
*p
, void *ctx
)
939 struct fs_path
*pt
= ctx
;
941 ret
= fs_path_copy(pt
, p
);
945 /* we want the first only */
950 * Retrieve the first path of an inode. If an inode has more then one
951 * ref/hardlink, this is ignored.
953 static int get_inode_path(struct btrfs_root
*root
,
954 u64 ino
, struct fs_path
*path
)
957 struct btrfs_key key
, found_key
;
958 struct btrfs_path
*p
;
960 p
= alloc_path_for_send();
967 key
.type
= BTRFS_INODE_REF_KEY
;
970 ret
= btrfs_search_slot_for_read(root
, &key
, p
, 1, 0);
977 btrfs_item_key_to_cpu(p
->nodes
[0], &found_key
, p
->slots
[0]);
978 if (found_key
.objectid
!= ino
||
979 (found_key
.type
!= BTRFS_INODE_REF_KEY
&&
980 found_key
.type
!= BTRFS_INODE_EXTREF_KEY
)) {
985 ret
= iterate_inode_ref(root
, p
, &found_key
, 1,
986 __copy_first_ref
, path
);
997 struct send_ctx
*sctx
;
999 /* number of total found references */
1003 * used for clones found in send_root. clones found behind cur_objectid
1004 * and cur_offset are not considered as allowed clones.
1009 /* may be truncated in case it's the last extent in a file */
1012 /* Just to check for bugs in backref resolving */
1016 static int __clone_root_cmp_bsearch(const void *key
, const void *elt
)
1018 u64 root
= (u64
)(uintptr_t)key
;
1019 struct clone_root
*cr
= (struct clone_root
*)elt
;
1021 if (root
< cr
->root
->objectid
)
1023 if (root
> cr
->root
->objectid
)
1028 static int __clone_root_cmp_sort(const void *e1
, const void *e2
)
1030 struct clone_root
*cr1
= (struct clone_root
*)e1
;
1031 struct clone_root
*cr2
= (struct clone_root
*)e2
;
1033 if (cr1
->root
->objectid
< cr2
->root
->objectid
)
1035 if (cr1
->root
->objectid
> cr2
->root
->objectid
)
1041 * Called for every backref that is found for the current extent.
1042 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1044 static int __iterate_backrefs(u64 ino
, u64 offset
, u64 root
, void *ctx_
)
1046 struct backref_ctx
*bctx
= ctx_
;
1047 struct clone_root
*found
;
1051 /* First check if the root is in the list of accepted clone sources */
1052 found
= bsearch((void *)(uintptr_t)root
, bctx
->sctx
->clone_roots
,
1053 bctx
->sctx
->clone_roots_cnt
,
1054 sizeof(struct clone_root
),
1055 __clone_root_cmp_bsearch
);
1059 if (found
->root
== bctx
->sctx
->send_root
&&
1060 ino
== bctx
->cur_objectid
&&
1061 offset
== bctx
->cur_offset
) {
1062 bctx
->found_itself
= 1;
1066 * There are inodes that have extents that lie behind its i_size. Don't
1067 * accept clones from these extents.
1069 ret
= get_inode_info(found
->root
, ino
, &i_size
, NULL
, NULL
, NULL
, NULL
,
1074 if (offset
+ bctx
->extent_len
> i_size
)
1078 * Make sure we don't consider clones from send_root that are
1079 * behind the current inode/offset.
1081 if (found
->root
== bctx
->sctx
->send_root
) {
1083 * TODO for the moment we don't accept clones from the inode
1084 * that is currently send. We may change this when
1085 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1088 if (ino
>= bctx
->cur_objectid
)
1091 if (ino
> bctx
->cur_objectid
)
1093 if (offset
+ bctx
->extent_len
> bctx
->cur_offset
)
1099 found
->found_refs
++;
1100 if (ino
< found
->ino
) {
1102 found
->offset
= offset
;
1103 } else if (found
->ino
== ino
) {
1105 * same extent found more then once in the same file.
1107 if (found
->offset
> offset
+ bctx
->extent_len
)
1108 found
->offset
= offset
;
1115 * Given an inode, offset and extent item, it finds a good clone for a clone
1116 * instruction. Returns -ENOENT when none could be found. The function makes
1117 * sure that the returned clone is usable at the point where sending is at the
1118 * moment. This means, that no clones are accepted which lie behind the current
1121 * path must point to the extent item when called.
1123 static int find_extent_clone(struct send_ctx
*sctx
,
1124 struct btrfs_path
*path
,
1125 u64 ino
, u64 data_offset
,
1127 struct clone_root
**found
)
1134 u64 extent_item_pos
;
1136 struct btrfs_file_extent_item
*fi
;
1137 struct extent_buffer
*eb
= path
->nodes
[0];
1138 struct backref_ctx
*backref_ctx
= NULL
;
1139 struct clone_root
*cur_clone_root
;
1140 struct btrfs_key found_key
;
1141 struct btrfs_path
*tmp_path
;
1145 tmp_path
= alloc_path_for_send();
1149 backref_ctx
= kmalloc(sizeof(*backref_ctx
), GFP_NOFS
);
1155 if (data_offset
>= ino_size
) {
1157 * There may be extents that lie behind the file's size.
1158 * I at least had this in combination with snapshotting while
1159 * writing large files.
1165 fi
= btrfs_item_ptr(eb
, path
->slots
[0],
1166 struct btrfs_file_extent_item
);
1167 extent_type
= btrfs_file_extent_type(eb
, fi
);
1168 if (extent_type
== BTRFS_FILE_EXTENT_INLINE
) {
1172 compressed
= btrfs_file_extent_compression(eb
, fi
);
1174 num_bytes
= btrfs_file_extent_num_bytes(eb
, fi
);
1175 disk_byte
= btrfs_file_extent_disk_bytenr(eb
, fi
);
1176 if (disk_byte
== 0) {
1180 logical
= disk_byte
+ btrfs_file_extent_offset(eb
, fi
);
1182 ret
= extent_from_logical(sctx
->send_root
->fs_info
, disk_byte
, tmp_path
,
1183 &found_key
, &flags
);
1184 btrfs_release_path(tmp_path
);
1188 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
1194 * Setup the clone roots.
1196 for (i
= 0; i
< sctx
->clone_roots_cnt
; i
++) {
1197 cur_clone_root
= sctx
->clone_roots
+ i
;
1198 cur_clone_root
->ino
= (u64
)-1;
1199 cur_clone_root
->offset
= 0;
1200 cur_clone_root
->found_refs
= 0;
1203 backref_ctx
->sctx
= sctx
;
1204 backref_ctx
->found
= 0;
1205 backref_ctx
->cur_objectid
= ino
;
1206 backref_ctx
->cur_offset
= data_offset
;
1207 backref_ctx
->found_itself
= 0;
1208 backref_ctx
->extent_len
= num_bytes
;
1211 * The last extent of a file may be too large due to page alignment.
1212 * We need to adjust extent_len in this case so that the checks in
1213 * __iterate_backrefs work.
1215 if (data_offset
+ num_bytes
>= ino_size
)
1216 backref_ctx
->extent_len
= ino_size
- data_offset
;
1219 * Now collect all backrefs.
1221 if (compressed
== BTRFS_COMPRESS_NONE
)
1222 extent_item_pos
= logical
- found_key
.objectid
;
1224 extent_item_pos
= 0;
1226 extent_item_pos
= logical
- found_key
.objectid
;
1227 ret
= iterate_extent_inodes(sctx
->send_root
->fs_info
,
1228 found_key
.objectid
, extent_item_pos
, 1,
1229 __iterate_backrefs
, backref_ctx
);
1234 if (!backref_ctx
->found_itself
) {
1235 /* found a bug in backref code? */
1237 printk(KERN_ERR
"btrfs: ERROR did not find backref in "
1238 "send_root. inode=%llu, offset=%llu, "
1239 "disk_byte=%llu found extent=%llu\n",
1240 ino
, data_offset
, disk_byte
, found_key
.objectid
);
1244 verbose_printk(KERN_DEBUG
"btrfs: find_extent_clone: data_offset=%llu, "
1246 "num_bytes=%llu, logical=%llu\n",
1247 data_offset
, ino
, num_bytes
, logical
);
1249 if (!backref_ctx
->found
)
1250 verbose_printk("btrfs: no clones found\n");
1252 cur_clone_root
= NULL
;
1253 for (i
= 0; i
< sctx
->clone_roots_cnt
; i
++) {
1254 if (sctx
->clone_roots
[i
].found_refs
) {
1255 if (!cur_clone_root
)
1256 cur_clone_root
= sctx
->clone_roots
+ i
;
1257 else if (sctx
->clone_roots
[i
].root
== sctx
->send_root
)
1258 /* prefer clones from send_root over others */
1259 cur_clone_root
= sctx
->clone_roots
+ i
;
1264 if (cur_clone_root
) {
1265 *found
= cur_clone_root
;
1272 btrfs_free_path(tmp_path
);
1277 static int read_symlink(struct btrfs_root
*root
,
1279 struct fs_path
*dest
)
1282 struct btrfs_path
*path
;
1283 struct btrfs_key key
;
1284 struct btrfs_file_extent_item
*ei
;
1290 path
= alloc_path_for_send();
1295 key
.type
= BTRFS_EXTENT_DATA_KEY
;
1297 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
1302 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
1303 struct btrfs_file_extent_item
);
1304 type
= btrfs_file_extent_type(path
->nodes
[0], ei
);
1305 compression
= btrfs_file_extent_compression(path
->nodes
[0], ei
);
1306 BUG_ON(type
!= BTRFS_FILE_EXTENT_INLINE
);
1307 BUG_ON(compression
);
1309 off
= btrfs_file_extent_inline_start(ei
);
1310 len
= btrfs_file_extent_inline_len(path
->nodes
[0], ei
);
1312 ret
= fs_path_add_from_extent_buffer(dest
, path
->nodes
[0], off
, len
);
1315 btrfs_free_path(path
);
1320 * Helper function to generate a file name that is unique in the root of
1321 * send_root and parent_root. This is used to generate names for orphan inodes.
1323 static int gen_unique_name(struct send_ctx
*sctx
,
1325 struct fs_path
*dest
)
1328 struct btrfs_path
*path
;
1329 struct btrfs_dir_item
*di
;
1334 path
= alloc_path_for_send();
1339 len
= snprintf(tmp
, sizeof(tmp
) - 1, "o%llu-%llu-%llu",
1341 if (len
>= sizeof(tmp
)) {
1342 /* should really not happen */
1347 di
= btrfs_lookup_dir_item(NULL
, sctx
->send_root
,
1348 path
, BTRFS_FIRST_FREE_OBJECTID
,
1349 tmp
, strlen(tmp
), 0);
1350 btrfs_release_path(path
);
1356 /* not unique, try again */
1361 if (!sctx
->parent_root
) {
1367 di
= btrfs_lookup_dir_item(NULL
, sctx
->parent_root
,
1368 path
, BTRFS_FIRST_FREE_OBJECTID
,
1369 tmp
, strlen(tmp
), 0);
1370 btrfs_release_path(path
);
1376 /* not unique, try again */
1384 ret
= fs_path_add(dest
, tmp
, strlen(tmp
));
1387 btrfs_free_path(path
);
1392 inode_state_no_change
,
1393 inode_state_will_create
,
1394 inode_state_did_create
,
1395 inode_state_will_delete
,
1396 inode_state_did_delete
,
1399 static int get_cur_inode_state(struct send_ctx
*sctx
, u64 ino
, u64 gen
)
1407 ret
= get_inode_info(sctx
->send_root
, ino
, NULL
, &left_gen
, NULL
, NULL
,
1409 if (ret
< 0 && ret
!= -ENOENT
)
1413 if (!sctx
->parent_root
) {
1414 right_ret
= -ENOENT
;
1416 ret
= get_inode_info(sctx
->parent_root
, ino
, NULL
, &right_gen
,
1417 NULL
, NULL
, NULL
, NULL
);
1418 if (ret
< 0 && ret
!= -ENOENT
)
1423 if (!left_ret
&& !right_ret
) {
1424 if (left_gen
== gen
&& right_gen
== gen
) {
1425 ret
= inode_state_no_change
;
1426 } else if (left_gen
== gen
) {
1427 if (ino
< sctx
->send_progress
)
1428 ret
= inode_state_did_create
;
1430 ret
= inode_state_will_create
;
1431 } else if (right_gen
== gen
) {
1432 if (ino
< sctx
->send_progress
)
1433 ret
= inode_state_did_delete
;
1435 ret
= inode_state_will_delete
;
1439 } else if (!left_ret
) {
1440 if (left_gen
== gen
) {
1441 if (ino
< sctx
->send_progress
)
1442 ret
= inode_state_did_create
;
1444 ret
= inode_state_will_create
;
1448 } else if (!right_ret
) {
1449 if (right_gen
== gen
) {
1450 if (ino
< sctx
->send_progress
)
1451 ret
= inode_state_did_delete
;
1453 ret
= inode_state_will_delete
;
1465 static int is_inode_existent(struct send_ctx
*sctx
, u64 ino
, u64 gen
)
1469 ret
= get_cur_inode_state(sctx
, ino
, gen
);
1473 if (ret
== inode_state_no_change
||
1474 ret
== inode_state_did_create
||
1475 ret
== inode_state_will_delete
)
1485 * Helper function to lookup a dir item in a dir.
1487 static int lookup_dir_item_inode(struct btrfs_root
*root
,
1488 u64 dir
, const char *name
, int name_len
,
1493 struct btrfs_dir_item
*di
;
1494 struct btrfs_key key
;
1495 struct btrfs_path
*path
;
1497 path
= alloc_path_for_send();
1501 di
= btrfs_lookup_dir_item(NULL
, root
, path
,
1502 dir
, name
, name_len
, 0);
1511 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &key
);
1512 *found_inode
= key
.objectid
;
1513 *found_type
= btrfs_dir_type(path
->nodes
[0], di
);
1516 btrfs_free_path(path
);
1521 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
1522 * generation of the parent dir and the name of the dir entry.
1524 static int get_first_ref(struct btrfs_root
*root
, u64 ino
,
1525 u64
*dir
, u64
*dir_gen
, struct fs_path
*name
)
1528 struct btrfs_key key
;
1529 struct btrfs_key found_key
;
1530 struct btrfs_path
*path
;
1534 path
= alloc_path_for_send();
1539 key
.type
= BTRFS_INODE_REF_KEY
;
1542 ret
= btrfs_search_slot_for_read(root
, &key
, path
, 1, 0);
1546 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
,
1548 if (ret
|| found_key
.objectid
!= ino
||
1549 (found_key
.type
!= BTRFS_INODE_REF_KEY
&&
1550 found_key
.type
!= BTRFS_INODE_EXTREF_KEY
)) {
1555 if (key
.type
== BTRFS_INODE_REF_KEY
) {
1556 struct btrfs_inode_ref
*iref
;
1557 iref
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
1558 struct btrfs_inode_ref
);
1559 len
= btrfs_inode_ref_name_len(path
->nodes
[0], iref
);
1560 ret
= fs_path_add_from_extent_buffer(name
, path
->nodes
[0],
1561 (unsigned long)(iref
+ 1),
1563 parent_dir
= found_key
.offset
;
1565 struct btrfs_inode_extref
*extref
;
1566 extref
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
1567 struct btrfs_inode_extref
);
1568 len
= btrfs_inode_extref_name_len(path
->nodes
[0], extref
);
1569 ret
= fs_path_add_from_extent_buffer(name
, path
->nodes
[0],
1570 (unsigned long)&extref
->name
, len
);
1571 parent_dir
= btrfs_inode_extref_parent(path
->nodes
[0], extref
);
1575 btrfs_release_path(path
);
1577 ret
= get_inode_info(root
, parent_dir
, NULL
, dir_gen
, NULL
, NULL
,
1585 btrfs_free_path(path
);
1589 static int is_first_ref(struct btrfs_root
*root
,
1591 const char *name
, int name_len
)
1594 struct fs_path
*tmp_name
;
1598 tmp_name
= fs_path_alloc();
1602 ret
= get_first_ref(root
, ino
, &tmp_dir
, &tmp_dir_gen
, tmp_name
);
1606 if (dir
!= tmp_dir
|| name_len
!= fs_path_len(tmp_name
)) {
1611 ret
= !memcmp(tmp_name
->start
, name
, name_len
);
1614 fs_path_free(tmp_name
);
1619 * Used by process_recorded_refs to determine if a new ref would overwrite an
1620 * already existing ref. In case it detects an overwrite, it returns the
1621 * inode/gen in who_ino/who_gen.
1622 * When an overwrite is detected, process_recorded_refs does proper orphanizing
1623 * to make sure later references to the overwritten inode are possible.
1624 * Orphanizing is however only required for the first ref of an inode.
1625 * process_recorded_refs does an additional is_first_ref check to see if
1626 * orphanizing is really required.
1628 static int will_overwrite_ref(struct send_ctx
*sctx
, u64 dir
, u64 dir_gen
,
1629 const char *name
, int name_len
,
1630 u64
*who_ino
, u64
*who_gen
)
1634 u64 other_inode
= 0;
1637 if (!sctx
->parent_root
)
1640 ret
= is_inode_existent(sctx
, dir
, dir_gen
);
1645 * If we have a parent root we need to verify that the parent dir was
1646 * not delted and then re-created, if it was then we have no overwrite
1647 * and we can just unlink this entry.
1649 if (sctx
->parent_root
) {
1650 ret
= get_inode_info(sctx
->parent_root
, dir
, NULL
, &gen
, NULL
,
1652 if (ret
< 0 && ret
!= -ENOENT
)
1662 ret
= lookup_dir_item_inode(sctx
->parent_root
, dir
, name
, name_len
,
1663 &other_inode
, &other_type
);
1664 if (ret
< 0 && ret
!= -ENOENT
)
1672 * Check if the overwritten ref was already processed. If yes, the ref
1673 * was already unlinked/moved, so we can safely assume that we will not
1674 * overwrite anything at this point in time.
1676 if (other_inode
> sctx
->send_progress
) {
1677 ret
= get_inode_info(sctx
->parent_root
, other_inode
, NULL
,
1678 who_gen
, NULL
, NULL
, NULL
, NULL
);
1683 *who_ino
= other_inode
;
1693 * Checks if the ref was overwritten by an already processed inode. This is
1694 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
1695 * thus the orphan name needs be used.
1696 * process_recorded_refs also uses it to avoid unlinking of refs that were
1699 static int did_overwrite_ref(struct send_ctx
*sctx
,
1700 u64 dir
, u64 dir_gen
,
1701 u64 ino
, u64 ino_gen
,
1702 const char *name
, int name_len
)
1709 if (!sctx
->parent_root
)
1712 ret
= is_inode_existent(sctx
, dir
, dir_gen
);
1716 /* check if the ref was overwritten by another ref */
1717 ret
= lookup_dir_item_inode(sctx
->send_root
, dir
, name
, name_len
,
1718 &ow_inode
, &other_type
);
1719 if (ret
< 0 && ret
!= -ENOENT
)
1722 /* was never and will never be overwritten */
1727 ret
= get_inode_info(sctx
->send_root
, ow_inode
, NULL
, &gen
, NULL
, NULL
,
1732 if (ow_inode
== ino
&& gen
== ino_gen
) {
1737 /* we know that it is or will be overwritten. check this now */
1738 if (ow_inode
< sctx
->send_progress
)
1748 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
1749 * that got overwritten. This is used by process_recorded_refs to determine
1750 * if it has to use the path as returned by get_cur_path or the orphan name.
1752 static int did_overwrite_first_ref(struct send_ctx
*sctx
, u64 ino
, u64 gen
)
1755 struct fs_path
*name
= NULL
;
1759 if (!sctx
->parent_root
)
1762 name
= fs_path_alloc();
1766 ret
= get_first_ref(sctx
->parent_root
, ino
, &dir
, &dir_gen
, name
);
1770 ret
= did_overwrite_ref(sctx
, dir
, dir_gen
, ino
, gen
,
1771 name
->start
, fs_path_len(name
));
1779 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
1780 * so we need to do some special handling in case we have clashes. This function
1781 * takes care of this with the help of name_cache_entry::radix_list.
1782 * In case of error, nce is kfreed.
1784 static int name_cache_insert(struct send_ctx
*sctx
,
1785 struct name_cache_entry
*nce
)
1788 struct list_head
*nce_head
;
1790 nce_head
= radix_tree_lookup(&sctx
->name_cache
,
1791 (unsigned long)nce
->ino
);
1793 nce_head
= kmalloc(sizeof(*nce_head
), GFP_NOFS
);
1798 INIT_LIST_HEAD(nce_head
);
1800 ret
= radix_tree_insert(&sctx
->name_cache
, nce
->ino
, nce_head
);
1807 list_add_tail(&nce
->radix_list
, nce_head
);
1808 list_add_tail(&nce
->list
, &sctx
->name_cache_list
);
1809 sctx
->name_cache_size
++;
1814 static void name_cache_delete(struct send_ctx
*sctx
,
1815 struct name_cache_entry
*nce
)
1817 struct list_head
*nce_head
;
1819 nce_head
= radix_tree_lookup(&sctx
->name_cache
,
1820 (unsigned long)nce
->ino
);
1823 list_del(&nce
->radix_list
);
1824 list_del(&nce
->list
);
1825 sctx
->name_cache_size
--;
1827 if (list_empty(nce_head
)) {
1828 radix_tree_delete(&sctx
->name_cache
, (unsigned long)nce
->ino
);
1833 static struct name_cache_entry
*name_cache_search(struct send_ctx
*sctx
,
1836 struct list_head
*nce_head
;
1837 struct name_cache_entry
*cur
;
1839 nce_head
= radix_tree_lookup(&sctx
->name_cache
, (unsigned long)ino
);
1843 list_for_each_entry(cur
, nce_head
, radix_list
) {
1844 if (cur
->ino
== ino
&& cur
->gen
== gen
)
1851 * Removes the entry from the list and adds it back to the end. This marks the
1852 * entry as recently used so that name_cache_clean_unused does not remove it.
1854 static void name_cache_used(struct send_ctx
*sctx
, struct name_cache_entry
*nce
)
1856 list_del(&nce
->list
);
1857 list_add_tail(&nce
->list
, &sctx
->name_cache_list
);
1861 * Remove some entries from the beginning of name_cache_list.
1863 static void name_cache_clean_unused(struct send_ctx
*sctx
)
1865 struct name_cache_entry
*nce
;
1867 if (sctx
->name_cache_size
< SEND_CTX_NAME_CACHE_CLEAN_SIZE
)
1870 while (sctx
->name_cache_size
> SEND_CTX_MAX_NAME_CACHE_SIZE
) {
1871 nce
= list_entry(sctx
->name_cache_list
.next
,
1872 struct name_cache_entry
, list
);
1873 name_cache_delete(sctx
, nce
);
1878 static void name_cache_free(struct send_ctx
*sctx
)
1880 struct name_cache_entry
*nce
;
1882 while (!list_empty(&sctx
->name_cache_list
)) {
1883 nce
= list_entry(sctx
->name_cache_list
.next
,
1884 struct name_cache_entry
, list
);
1885 name_cache_delete(sctx
, nce
);
1891 * Used by get_cur_path for each ref up to the root.
1892 * Returns 0 if it succeeded.
1893 * Returns 1 if the inode is not existent or got overwritten. In that case, the
1894 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
1895 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
1896 * Returns <0 in case of error.
1898 static int __get_cur_name_and_parent(struct send_ctx
*sctx
,
1902 struct fs_path
*dest
)
1906 struct btrfs_path
*path
= NULL
;
1907 struct name_cache_entry
*nce
= NULL
;
1910 * First check if we already did a call to this function with the same
1911 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
1912 * return the cached result.
1914 nce
= name_cache_search(sctx
, ino
, gen
);
1916 if (ino
< sctx
->send_progress
&& nce
->need_later_update
) {
1917 name_cache_delete(sctx
, nce
);
1921 name_cache_used(sctx
, nce
);
1922 *parent_ino
= nce
->parent_ino
;
1923 *parent_gen
= nce
->parent_gen
;
1924 ret
= fs_path_add(dest
, nce
->name
, nce
->name_len
);
1932 path
= alloc_path_for_send();
1937 * If the inode is not existent yet, add the orphan name and return 1.
1938 * This should only happen for the parent dir that we determine in
1941 ret
= is_inode_existent(sctx
, ino
, gen
);
1946 ret
= gen_unique_name(sctx
, ino
, gen
, dest
);
1954 * Depending on whether the inode was already processed or not, use
1955 * send_root or parent_root for ref lookup.
1957 if (ino
< sctx
->send_progress
)
1958 ret
= get_first_ref(sctx
->send_root
, ino
,
1959 parent_ino
, parent_gen
, dest
);
1961 ret
= get_first_ref(sctx
->parent_root
, ino
,
1962 parent_ino
, parent_gen
, dest
);
1967 * Check if the ref was overwritten by an inode's ref that was processed
1968 * earlier. If yes, treat as orphan and return 1.
1970 ret
= did_overwrite_ref(sctx
, *parent_ino
, *parent_gen
, ino
, gen
,
1971 dest
->start
, dest
->end
- dest
->start
);
1975 fs_path_reset(dest
);
1976 ret
= gen_unique_name(sctx
, ino
, gen
, dest
);
1984 * Store the result of the lookup in the name cache.
1986 nce
= kmalloc(sizeof(*nce
) + fs_path_len(dest
) + 1, GFP_NOFS
);
1994 nce
->parent_ino
= *parent_ino
;
1995 nce
->parent_gen
= *parent_gen
;
1996 nce
->name_len
= fs_path_len(dest
);
1998 strcpy(nce
->name
, dest
->start
);
2000 if (ino
< sctx
->send_progress
)
2001 nce
->need_later_update
= 0;
2003 nce
->need_later_update
= 1;
2005 nce_ret
= name_cache_insert(sctx
, nce
);
2008 name_cache_clean_unused(sctx
);
2011 btrfs_free_path(path
);
2016 * Magic happens here. This function returns the first ref to an inode as it
2017 * would look like while receiving the stream at this point in time.
2018 * We walk the path up to the root. For every inode in between, we check if it
2019 * was already processed/sent. If yes, we continue with the parent as found
2020 * in send_root. If not, we continue with the parent as found in parent_root.
2021 * If we encounter an inode that was deleted at this point in time, we use the
2022 * inodes "orphan" name instead of the real name and stop. Same with new inodes
2023 * that were not created yet and overwritten inodes/refs.
2025 * When do we have have orphan inodes:
2026 * 1. When an inode is freshly created and thus no valid refs are available yet
2027 * 2. When a directory lost all it's refs (deleted) but still has dir items
2028 * inside which were not processed yet (pending for move/delete). If anyone
2029 * tried to get the path to the dir items, it would get a path inside that
2031 * 3. When an inode is moved around or gets new links, it may overwrite the ref
2032 * of an unprocessed inode. If in that case the first ref would be
2033 * overwritten, the overwritten inode gets "orphanized". Later when we
2034 * process this overwritten inode, it is restored at a new place by moving
2037 * sctx->send_progress tells this function at which point in time receiving
2040 static int get_cur_path(struct send_ctx
*sctx
, u64 ino
, u64 gen
,
2041 struct fs_path
*dest
)
2044 struct fs_path
*name
= NULL
;
2045 u64 parent_inode
= 0;
2049 name
= fs_path_alloc();
2056 fs_path_reset(dest
);
2058 while (!stop
&& ino
!= BTRFS_FIRST_FREE_OBJECTID
) {
2059 fs_path_reset(name
);
2061 ret
= __get_cur_name_and_parent(sctx
, ino
, gen
,
2062 &parent_inode
, &parent_gen
, name
);
2068 ret
= fs_path_add_path(dest
, name
);
2079 fs_path_unreverse(dest
);
2084 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2086 static int send_subvol_begin(struct send_ctx
*sctx
)
2089 struct btrfs_root
*send_root
= sctx
->send_root
;
2090 struct btrfs_root
*parent_root
= sctx
->parent_root
;
2091 struct btrfs_path
*path
;
2092 struct btrfs_key key
;
2093 struct btrfs_root_ref
*ref
;
2094 struct extent_buffer
*leaf
;
2098 path
= alloc_path_for_send();
2102 name
= kmalloc(BTRFS_PATH_NAME_MAX
, GFP_NOFS
);
2104 btrfs_free_path(path
);
2108 key
.objectid
= send_root
->objectid
;
2109 key
.type
= BTRFS_ROOT_BACKREF_KEY
;
2112 ret
= btrfs_search_slot_for_read(send_root
->fs_info
->tree_root
,
2121 leaf
= path
->nodes
[0];
2122 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
2123 if (key
.type
!= BTRFS_ROOT_BACKREF_KEY
||
2124 key
.objectid
!= send_root
->objectid
) {
2128 ref
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_root_ref
);
2129 namelen
= btrfs_root_ref_name_len(leaf
, ref
);
2130 read_extent_buffer(leaf
, name
, (unsigned long)(ref
+ 1), namelen
);
2131 btrfs_release_path(path
);
2134 ret
= begin_cmd(sctx
, BTRFS_SEND_C_SNAPSHOT
);
2138 ret
= begin_cmd(sctx
, BTRFS_SEND_C_SUBVOL
);
2143 TLV_PUT_STRING(sctx
, BTRFS_SEND_A_PATH
, name
, namelen
);
2144 TLV_PUT_UUID(sctx
, BTRFS_SEND_A_UUID
,
2145 sctx
->send_root
->root_item
.uuid
);
2146 TLV_PUT_U64(sctx
, BTRFS_SEND_A_CTRANSID
,
2147 le64_to_cpu(sctx
->send_root
->root_item
.ctransid
));
2149 TLV_PUT_UUID(sctx
, BTRFS_SEND_A_CLONE_UUID
,
2150 sctx
->parent_root
->root_item
.uuid
);
2151 TLV_PUT_U64(sctx
, BTRFS_SEND_A_CLONE_CTRANSID
,
2152 le64_to_cpu(sctx
->parent_root
->root_item
.ctransid
));
2155 ret
= send_cmd(sctx
);
2159 btrfs_free_path(path
);
2164 static int send_truncate(struct send_ctx
*sctx
, u64 ino
, u64 gen
, u64 size
)
2169 verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino
, size
);
2171 p
= fs_path_alloc();
2175 ret
= begin_cmd(sctx
, BTRFS_SEND_C_TRUNCATE
);
2179 ret
= get_cur_path(sctx
, ino
, gen
, p
);
2182 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
2183 TLV_PUT_U64(sctx
, BTRFS_SEND_A_SIZE
, size
);
2185 ret
= send_cmd(sctx
);
2193 static int send_chmod(struct send_ctx
*sctx
, u64 ino
, u64 gen
, u64 mode
)
2198 verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino
, mode
);
2200 p
= fs_path_alloc();
2204 ret
= begin_cmd(sctx
, BTRFS_SEND_C_CHMOD
);
2208 ret
= get_cur_path(sctx
, ino
, gen
, p
);
2211 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
2212 TLV_PUT_U64(sctx
, BTRFS_SEND_A_MODE
, mode
& 07777);
2214 ret
= send_cmd(sctx
);
2222 static int send_chown(struct send_ctx
*sctx
, u64 ino
, u64 gen
, u64 uid
, u64 gid
)
2227 verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino
, uid
, gid
);
2229 p
= fs_path_alloc();
2233 ret
= begin_cmd(sctx
, BTRFS_SEND_C_CHOWN
);
2237 ret
= get_cur_path(sctx
, ino
, gen
, p
);
2240 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
2241 TLV_PUT_U64(sctx
, BTRFS_SEND_A_UID
, uid
);
2242 TLV_PUT_U64(sctx
, BTRFS_SEND_A_GID
, gid
);
2244 ret
= send_cmd(sctx
);
2252 static int send_utimes(struct send_ctx
*sctx
, u64 ino
, u64 gen
)
2255 struct fs_path
*p
= NULL
;
2256 struct btrfs_inode_item
*ii
;
2257 struct btrfs_path
*path
= NULL
;
2258 struct extent_buffer
*eb
;
2259 struct btrfs_key key
;
2262 verbose_printk("btrfs: send_utimes %llu\n", ino
);
2264 p
= fs_path_alloc();
2268 path
= alloc_path_for_send();
2275 key
.type
= BTRFS_INODE_ITEM_KEY
;
2277 ret
= btrfs_search_slot(NULL
, sctx
->send_root
, &key
, path
, 0, 0);
2281 eb
= path
->nodes
[0];
2282 slot
= path
->slots
[0];
2283 ii
= btrfs_item_ptr(eb
, slot
, struct btrfs_inode_item
);
2285 ret
= begin_cmd(sctx
, BTRFS_SEND_C_UTIMES
);
2289 ret
= get_cur_path(sctx
, ino
, gen
, p
);
2292 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
2293 TLV_PUT_BTRFS_TIMESPEC(sctx
, BTRFS_SEND_A_ATIME
, eb
,
2294 btrfs_inode_atime(ii
));
2295 TLV_PUT_BTRFS_TIMESPEC(sctx
, BTRFS_SEND_A_MTIME
, eb
,
2296 btrfs_inode_mtime(ii
));
2297 TLV_PUT_BTRFS_TIMESPEC(sctx
, BTRFS_SEND_A_CTIME
, eb
,
2298 btrfs_inode_ctime(ii
));
2299 /* TODO Add otime support when the otime patches get into upstream */
2301 ret
= send_cmd(sctx
);
2306 btrfs_free_path(path
);
2311 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2312 * a valid path yet because we did not process the refs yet. So, the inode
2313 * is created as orphan.
2315 static int send_create_inode(struct send_ctx
*sctx
, u64 ino
)
2324 verbose_printk("btrfs: send_create_inode %llu\n", ino
);
2326 p
= fs_path_alloc();
2330 ret
= get_inode_info(sctx
->send_root
, ino
, NULL
, &gen
, &mode
, NULL
,
2335 if (S_ISREG(mode
)) {
2336 cmd
= BTRFS_SEND_C_MKFILE
;
2337 } else if (S_ISDIR(mode
)) {
2338 cmd
= BTRFS_SEND_C_MKDIR
;
2339 } else if (S_ISLNK(mode
)) {
2340 cmd
= BTRFS_SEND_C_SYMLINK
;
2341 } else if (S_ISCHR(mode
) || S_ISBLK(mode
)) {
2342 cmd
= BTRFS_SEND_C_MKNOD
;
2343 } else if (S_ISFIFO(mode
)) {
2344 cmd
= BTRFS_SEND_C_MKFIFO
;
2345 } else if (S_ISSOCK(mode
)) {
2346 cmd
= BTRFS_SEND_C_MKSOCK
;
2348 printk(KERN_WARNING
"btrfs: unexpected inode type %o",
2349 (int)(mode
& S_IFMT
));
2354 ret
= begin_cmd(sctx
, cmd
);
2358 ret
= gen_unique_name(sctx
, ino
, gen
, p
);
2362 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
2363 TLV_PUT_U64(sctx
, BTRFS_SEND_A_INO
, ino
);
2365 if (S_ISLNK(mode
)) {
2367 ret
= read_symlink(sctx
->send_root
, ino
, p
);
2370 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH_LINK
, p
);
2371 } else if (S_ISCHR(mode
) || S_ISBLK(mode
) ||
2372 S_ISFIFO(mode
) || S_ISSOCK(mode
)) {
2373 TLV_PUT_U64(sctx
, BTRFS_SEND_A_RDEV
, new_encode_dev(rdev
));
2374 TLV_PUT_U64(sctx
, BTRFS_SEND_A_MODE
, mode
);
2377 ret
= send_cmd(sctx
);
2389 * We need some special handling for inodes that get processed before the parent
2390 * directory got created. See process_recorded_refs for details.
2391 * This function does the check if we already created the dir out of order.
2393 static int did_create_dir(struct send_ctx
*sctx
, u64 dir
)
2396 struct btrfs_path
*path
= NULL
;
2397 struct btrfs_key key
;
2398 struct btrfs_key found_key
;
2399 struct btrfs_key di_key
;
2400 struct extent_buffer
*eb
;
2401 struct btrfs_dir_item
*di
;
2404 path
= alloc_path_for_send();
2411 key
.type
= BTRFS_DIR_INDEX_KEY
;
2414 ret
= btrfs_search_slot_for_read(sctx
->send_root
, &key
, path
,
2419 eb
= path
->nodes
[0];
2420 slot
= path
->slots
[0];
2421 btrfs_item_key_to_cpu(eb
, &found_key
, slot
);
2423 if (ret
|| found_key
.objectid
!= key
.objectid
||
2424 found_key
.type
!= key
.type
) {
2429 di
= btrfs_item_ptr(eb
, slot
, struct btrfs_dir_item
);
2430 btrfs_dir_item_key_to_cpu(eb
, di
, &di_key
);
2432 if (di_key
.type
!= BTRFS_ROOT_ITEM_KEY
&&
2433 di_key
.objectid
< sctx
->send_progress
) {
2438 key
.offset
= found_key
.offset
+ 1;
2439 btrfs_release_path(path
);
2443 btrfs_free_path(path
);
2448 * Only creates the inode if it is:
2449 * 1. Not a directory
2450 * 2. Or a directory which was not created already due to out of order
2451 * directories. See did_create_dir and process_recorded_refs for details.
2453 static int send_create_inode_if_needed(struct send_ctx
*sctx
)
2457 if (S_ISDIR(sctx
->cur_inode_mode
)) {
2458 ret
= did_create_dir(sctx
, sctx
->cur_ino
);
2467 ret
= send_create_inode(sctx
, sctx
->cur_ino
);
2475 struct recorded_ref
{
2476 struct list_head list
;
2479 struct fs_path
*full_path
;
2487 * We need to process new refs before deleted refs, but compare_tree gives us
2488 * everything mixed. So we first record all refs and later process them.
2489 * This function is a helper to record one ref.
2491 static int record_ref(struct list_head
*head
, u64 dir
,
2492 u64 dir_gen
, struct fs_path
*path
)
2494 struct recorded_ref
*ref
;
2496 ref
= kmalloc(sizeof(*ref
), GFP_NOFS
);
2501 ref
->dir_gen
= dir_gen
;
2502 ref
->full_path
= path
;
2504 ref
->name
= (char *)kbasename(ref
->full_path
->start
);
2505 ref
->name_len
= ref
->full_path
->end
- ref
->name
;
2506 ref
->dir_path
= ref
->full_path
->start
;
2507 if (ref
->name
== ref
->full_path
->start
)
2508 ref
->dir_path_len
= 0;
2510 ref
->dir_path_len
= ref
->full_path
->end
-
2511 ref
->full_path
->start
- 1 - ref
->name_len
;
2513 list_add_tail(&ref
->list
, head
);
2517 static int dup_ref(struct recorded_ref
*ref
, struct list_head
*list
)
2519 struct recorded_ref
*new;
2521 new = kmalloc(sizeof(*ref
), GFP_NOFS
);
2525 new->dir
= ref
->dir
;
2526 new->dir_gen
= ref
->dir_gen
;
2527 new->full_path
= NULL
;
2528 INIT_LIST_HEAD(&new->list
);
2529 list_add_tail(&new->list
, list
);
2533 static void __free_recorded_refs(struct list_head
*head
)
2535 struct recorded_ref
*cur
;
2537 while (!list_empty(head
)) {
2538 cur
= list_entry(head
->next
, struct recorded_ref
, list
);
2539 fs_path_free(cur
->full_path
);
2540 list_del(&cur
->list
);
2545 static void free_recorded_refs(struct send_ctx
*sctx
)
2547 __free_recorded_refs(&sctx
->new_refs
);
2548 __free_recorded_refs(&sctx
->deleted_refs
);
2552 * Renames/moves a file/dir to its orphan name. Used when the first
2553 * ref of an unprocessed inode gets overwritten and for all non empty
2556 static int orphanize_inode(struct send_ctx
*sctx
, u64 ino
, u64 gen
,
2557 struct fs_path
*path
)
2560 struct fs_path
*orphan
;
2562 orphan
= fs_path_alloc();
2566 ret
= gen_unique_name(sctx
, ino
, gen
, orphan
);
2570 ret
= send_rename(sctx
, path
, orphan
);
2573 fs_path_free(orphan
);
2578 * Returns 1 if a directory can be removed at this point in time.
2579 * We check this by iterating all dir items and checking if the inode behind
2580 * the dir item was already processed.
2582 static int can_rmdir(struct send_ctx
*sctx
, u64 dir
, u64 send_progress
)
2585 struct btrfs_root
*root
= sctx
->parent_root
;
2586 struct btrfs_path
*path
;
2587 struct btrfs_key key
;
2588 struct btrfs_key found_key
;
2589 struct btrfs_key loc
;
2590 struct btrfs_dir_item
*di
;
2593 * Don't try to rmdir the top/root subvolume dir.
2595 if (dir
== BTRFS_FIRST_FREE_OBJECTID
)
2598 path
= alloc_path_for_send();
2603 key
.type
= BTRFS_DIR_INDEX_KEY
;
2607 ret
= btrfs_search_slot_for_read(root
, &key
, path
, 1, 0);
2611 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
,
2614 if (ret
|| found_key
.objectid
!= key
.objectid
||
2615 found_key
.type
!= key
.type
) {
2619 di
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
2620 struct btrfs_dir_item
);
2621 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &loc
);
2623 if (loc
.objectid
> send_progress
) {
2628 btrfs_release_path(path
);
2629 key
.offset
= found_key
.offset
+ 1;
2635 btrfs_free_path(path
);
2640 * This does all the move/link/unlink/rmdir magic.
2642 static int process_recorded_refs(struct send_ctx
*sctx
)
2645 struct recorded_ref
*cur
;
2646 struct recorded_ref
*cur2
;
2647 struct list_head check_dirs
;
2648 struct fs_path
*valid_path
= NULL
;
2651 int did_overwrite
= 0;
2654 verbose_printk("btrfs: process_recorded_refs %llu\n", sctx
->cur_ino
);
2657 * This should never happen as the root dir always has the same ref
2658 * which is always '..'
2660 BUG_ON(sctx
->cur_ino
<= BTRFS_FIRST_FREE_OBJECTID
);
2661 INIT_LIST_HEAD(&check_dirs
);
2663 valid_path
= fs_path_alloc();
2670 * First, check if the first ref of the current inode was overwritten
2671 * before. If yes, we know that the current inode was already orphanized
2672 * and thus use the orphan name. If not, we can use get_cur_path to
2673 * get the path of the first ref as it would like while receiving at
2674 * this point in time.
2675 * New inodes are always orphan at the beginning, so force to use the
2676 * orphan name in this case.
2677 * The first ref is stored in valid_path and will be updated if it
2678 * gets moved around.
2680 if (!sctx
->cur_inode_new
) {
2681 ret
= did_overwrite_first_ref(sctx
, sctx
->cur_ino
,
2682 sctx
->cur_inode_gen
);
2688 if (sctx
->cur_inode_new
|| did_overwrite
) {
2689 ret
= gen_unique_name(sctx
, sctx
->cur_ino
,
2690 sctx
->cur_inode_gen
, valid_path
);
2695 ret
= get_cur_path(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
,
2701 list_for_each_entry(cur
, &sctx
->new_refs
, list
) {
2703 * We may have refs where the parent directory does not exist
2704 * yet. This happens if the parent directories inum is higher
2705 * the the current inum. To handle this case, we create the
2706 * parent directory out of order. But we need to check if this
2707 * did already happen before due to other refs in the same dir.
2709 ret
= get_cur_inode_state(sctx
, cur
->dir
, cur
->dir_gen
);
2712 if (ret
== inode_state_will_create
) {
2715 * First check if any of the current inodes refs did
2716 * already create the dir.
2718 list_for_each_entry(cur2
, &sctx
->new_refs
, list
) {
2721 if (cur2
->dir
== cur
->dir
) {
2728 * If that did not happen, check if a previous inode
2729 * did already create the dir.
2732 ret
= did_create_dir(sctx
, cur
->dir
);
2736 ret
= send_create_inode(sctx
, cur
->dir
);
2743 * Check if this new ref would overwrite the first ref of
2744 * another unprocessed inode. If yes, orphanize the
2745 * overwritten inode. If we find an overwritten ref that is
2746 * not the first ref, simply unlink it.
2748 ret
= will_overwrite_ref(sctx
, cur
->dir
, cur
->dir_gen
,
2749 cur
->name
, cur
->name_len
,
2750 &ow_inode
, &ow_gen
);
2754 ret
= is_first_ref(sctx
->parent_root
,
2755 ow_inode
, cur
->dir
, cur
->name
,
2760 ret
= orphanize_inode(sctx
, ow_inode
, ow_gen
,
2765 ret
= send_unlink(sctx
, cur
->full_path
);
2772 * link/move the ref to the new place. If we have an orphan
2773 * inode, move it and update valid_path. If not, link or move
2774 * it depending on the inode mode.
2777 ret
= send_rename(sctx
, valid_path
, cur
->full_path
);
2781 ret
= fs_path_copy(valid_path
, cur
->full_path
);
2785 if (S_ISDIR(sctx
->cur_inode_mode
)) {
2787 * Dirs can't be linked, so move it. For moved
2788 * dirs, we always have one new and one deleted
2789 * ref. The deleted ref is ignored later.
2791 ret
= send_rename(sctx
, valid_path
,
2795 ret
= fs_path_copy(valid_path
, cur
->full_path
);
2799 ret
= send_link(sctx
, cur
->full_path
,
2805 ret
= dup_ref(cur
, &check_dirs
);
2810 if (S_ISDIR(sctx
->cur_inode_mode
) && sctx
->cur_inode_deleted
) {
2812 * Check if we can already rmdir the directory. If not,
2813 * orphanize it. For every dir item inside that gets deleted
2814 * later, we do this check again and rmdir it then if possible.
2815 * See the use of check_dirs for more details.
2817 ret
= can_rmdir(sctx
, sctx
->cur_ino
, sctx
->cur_ino
);
2821 ret
= send_rmdir(sctx
, valid_path
);
2824 } else if (!is_orphan
) {
2825 ret
= orphanize_inode(sctx
, sctx
->cur_ino
,
2826 sctx
->cur_inode_gen
, valid_path
);
2832 list_for_each_entry(cur
, &sctx
->deleted_refs
, list
) {
2833 ret
= dup_ref(cur
, &check_dirs
);
2837 } else if (S_ISDIR(sctx
->cur_inode_mode
) &&
2838 !list_empty(&sctx
->deleted_refs
)) {
2840 * We have a moved dir. Add the old parent to check_dirs
2842 cur
= list_entry(sctx
->deleted_refs
.next
, struct recorded_ref
,
2844 ret
= dup_ref(cur
, &check_dirs
);
2847 } else if (!S_ISDIR(sctx
->cur_inode_mode
)) {
2849 * We have a non dir inode. Go through all deleted refs and
2850 * unlink them if they were not already overwritten by other
2853 list_for_each_entry(cur
, &sctx
->deleted_refs
, list
) {
2854 ret
= did_overwrite_ref(sctx
, cur
->dir
, cur
->dir_gen
,
2855 sctx
->cur_ino
, sctx
->cur_inode_gen
,
2856 cur
->name
, cur
->name_len
);
2860 ret
= send_unlink(sctx
, cur
->full_path
);
2864 ret
= dup_ref(cur
, &check_dirs
);
2869 * If the inode is still orphan, unlink the orphan. This may
2870 * happen when a previous inode did overwrite the first ref
2871 * of this inode and no new refs were added for the current
2872 * inode. Unlinking does not mean that the inode is deleted in
2873 * all cases. There may still be links to this inode in other
2877 ret
= send_unlink(sctx
, valid_path
);
2884 * We did collect all parent dirs where cur_inode was once located. We
2885 * now go through all these dirs and check if they are pending for
2886 * deletion and if it's finally possible to perform the rmdir now.
2887 * We also update the inode stats of the parent dirs here.
2889 list_for_each_entry(cur
, &check_dirs
, list
) {
2891 * In case we had refs into dirs that were not processed yet,
2892 * we don't need to do the utime and rmdir logic for these dirs.
2893 * The dir will be processed later.
2895 if (cur
->dir
> sctx
->cur_ino
)
2898 ret
= get_cur_inode_state(sctx
, cur
->dir
, cur
->dir_gen
);
2902 if (ret
== inode_state_did_create
||
2903 ret
== inode_state_no_change
) {
2904 /* TODO delayed utimes */
2905 ret
= send_utimes(sctx
, cur
->dir
, cur
->dir_gen
);
2908 } else if (ret
== inode_state_did_delete
) {
2909 ret
= can_rmdir(sctx
, cur
->dir
, sctx
->cur_ino
);
2913 ret
= get_cur_path(sctx
, cur
->dir
,
2914 cur
->dir_gen
, valid_path
);
2917 ret
= send_rmdir(sctx
, valid_path
);
2927 __free_recorded_refs(&check_dirs
);
2928 free_recorded_refs(sctx
);
2929 fs_path_free(valid_path
);
2933 static int __record_new_ref(int num
, u64 dir
, int index
,
2934 struct fs_path
*name
,
2938 struct send_ctx
*sctx
= ctx
;
2942 p
= fs_path_alloc();
2946 ret
= get_inode_info(sctx
->send_root
, dir
, NULL
, &gen
, NULL
, NULL
,
2951 ret
= get_cur_path(sctx
, dir
, gen
, p
);
2954 ret
= fs_path_add_path(p
, name
);
2958 ret
= record_ref(&sctx
->new_refs
, dir
, gen
, p
);
2966 static int __record_deleted_ref(int num
, u64 dir
, int index
,
2967 struct fs_path
*name
,
2971 struct send_ctx
*sctx
= ctx
;
2975 p
= fs_path_alloc();
2979 ret
= get_inode_info(sctx
->parent_root
, dir
, NULL
, &gen
, NULL
, NULL
,
2984 ret
= get_cur_path(sctx
, dir
, gen
, p
);
2987 ret
= fs_path_add_path(p
, name
);
2991 ret
= record_ref(&sctx
->deleted_refs
, dir
, gen
, p
);
2999 static int record_new_ref(struct send_ctx
*sctx
)
3003 ret
= iterate_inode_ref(sctx
->send_root
, sctx
->left_path
,
3004 sctx
->cmp_key
, 0, __record_new_ref
, sctx
);
3013 static int record_deleted_ref(struct send_ctx
*sctx
)
3017 ret
= iterate_inode_ref(sctx
->parent_root
, sctx
->right_path
,
3018 sctx
->cmp_key
, 0, __record_deleted_ref
, sctx
);
3027 struct find_ref_ctx
{
3030 struct btrfs_root
*root
;
3031 struct fs_path
*name
;
3035 static int __find_iref(int num
, u64 dir
, int index
,
3036 struct fs_path
*name
,
3039 struct find_ref_ctx
*ctx
= ctx_
;
3043 if (dir
== ctx
->dir
&& fs_path_len(name
) == fs_path_len(ctx
->name
) &&
3044 strncmp(name
->start
, ctx
->name
->start
, fs_path_len(name
)) == 0) {
3046 * To avoid doing extra lookups we'll only do this if everything
3049 ret
= get_inode_info(ctx
->root
, dir
, NULL
, &dir_gen
, NULL
,
3053 if (dir_gen
!= ctx
->dir_gen
)
3055 ctx
->found_idx
= num
;
3061 static int find_iref(struct btrfs_root
*root
,
3062 struct btrfs_path
*path
,
3063 struct btrfs_key
*key
,
3064 u64 dir
, u64 dir_gen
, struct fs_path
*name
)
3067 struct find_ref_ctx ctx
;
3071 ctx
.dir_gen
= dir_gen
;
3075 ret
= iterate_inode_ref(root
, path
, key
, 0, __find_iref
, &ctx
);
3079 if (ctx
.found_idx
== -1)
3082 return ctx
.found_idx
;
3085 static int __record_changed_new_ref(int num
, u64 dir
, int index
,
3086 struct fs_path
*name
,
3091 struct send_ctx
*sctx
= ctx
;
3093 ret
= get_inode_info(sctx
->send_root
, dir
, NULL
, &dir_gen
, NULL
,
3098 ret
= find_iref(sctx
->parent_root
, sctx
->right_path
,
3099 sctx
->cmp_key
, dir
, dir_gen
, name
);
3101 ret
= __record_new_ref(num
, dir
, index
, name
, sctx
);
3108 static int __record_changed_deleted_ref(int num
, u64 dir
, int index
,
3109 struct fs_path
*name
,
3114 struct send_ctx
*sctx
= ctx
;
3116 ret
= get_inode_info(sctx
->parent_root
, dir
, NULL
, &dir_gen
, NULL
,
3121 ret
= find_iref(sctx
->send_root
, sctx
->left_path
, sctx
->cmp_key
,
3122 dir
, dir_gen
, name
);
3124 ret
= __record_deleted_ref(num
, dir
, index
, name
, sctx
);
3131 static int record_changed_ref(struct send_ctx
*sctx
)
3135 ret
= iterate_inode_ref(sctx
->send_root
, sctx
->left_path
,
3136 sctx
->cmp_key
, 0, __record_changed_new_ref
, sctx
);
3139 ret
= iterate_inode_ref(sctx
->parent_root
, sctx
->right_path
,
3140 sctx
->cmp_key
, 0, __record_changed_deleted_ref
, sctx
);
3150 * Record and process all refs at once. Needed when an inode changes the
3151 * generation number, which means that it was deleted and recreated.
3153 static int process_all_refs(struct send_ctx
*sctx
,
3154 enum btrfs_compare_tree_result cmd
)
3157 struct btrfs_root
*root
;
3158 struct btrfs_path
*path
;
3159 struct btrfs_key key
;
3160 struct btrfs_key found_key
;
3161 struct extent_buffer
*eb
;
3163 iterate_inode_ref_t cb
;
3165 path
= alloc_path_for_send();
3169 if (cmd
== BTRFS_COMPARE_TREE_NEW
) {
3170 root
= sctx
->send_root
;
3171 cb
= __record_new_ref
;
3172 } else if (cmd
== BTRFS_COMPARE_TREE_DELETED
) {
3173 root
= sctx
->parent_root
;
3174 cb
= __record_deleted_ref
;
3179 key
.objectid
= sctx
->cmp_key
->objectid
;
3180 key
.type
= BTRFS_INODE_REF_KEY
;
3183 ret
= btrfs_search_slot_for_read(root
, &key
, path
, 1, 0);
3189 eb
= path
->nodes
[0];
3190 slot
= path
->slots
[0];
3191 btrfs_item_key_to_cpu(eb
, &found_key
, slot
);
3193 if (found_key
.objectid
!= key
.objectid
||
3194 (found_key
.type
!= BTRFS_INODE_REF_KEY
&&
3195 found_key
.type
!= BTRFS_INODE_EXTREF_KEY
))
3198 ret
= iterate_inode_ref(root
, path
, &found_key
, 0, cb
, sctx
);
3199 btrfs_release_path(path
);
3203 key
.offset
= found_key
.offset
+ 1;
3205 btrfs_release_path(path
);
3207 ret
= process_recorded_refs(sctx
);
3210 btrfs_free_path(path
);
3214 static int send_set_xattr(struct send_ctx
*sctx
,
3215 struct fs_path
*path
,
3216 const char *name
, int name_len
,
3217 const char *data
, int data_len
)
3221 ret
= begin_cmd(sctx
, BTRFS_SEND_C_SET_XATTR
);
3225 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, path
);
3226 TLV_PUT_STRING(sctx
, BTRFS_SEND_A_XATTR_NAME
, name
, name_len
);
3227 TLV_PUT(sctx
, BTRFS_SEND_A_XATTR_DATA
, data
, data_len
);
3229 ret
= send_cmd(sctx
);
3236 static int send_remove_xattr(struct send_ctx
*sctx
,
3237 struct fs_path
*path
,
3238 const char *name
, int name_len
)
3242 ret
= begin_cmd(sctx
, BTRFS_SEND_C_REMOVE_XATTR
);
3246 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, path
);
3247 TLV_PUT_STRING(sctx
, BTRFS_SEND_A_XATTR_NAME
, name
, name_len
);
3249 ret
= send_cmd(sctx
);
3256 static int __process_new_xattr(int num
, struct btrfs_key
*di_key
,
3257 const char *name
, int name_len
,
3258 const char *data
, int data_len
,
3262 struct send_ctx
*sctx
= ctx
;
3264 posix_acl_xattr_header dummy_acl
;
3266 p
= fs_path_alloc();
3271 * This hack is needed because empty acl's are stored as zero byte
3272 * data in xattrs. Problem with that is, that receiving these zero byte
3273 * acl's will fail later. To fix this, we send a dummy acl list that
3274 * only contains the version number and no entries.
3276 if (!strncmp(name
, XATTR_NAME_POSIX_ACL_ACCESS
, name_len
) ||
3277 !strncmp(name
, XATTR_NAME_POSIX_ACL_DEFAULT
, name_len
)) {
3278 if (data_len
== 0) {
3279 dummy_acl
.a_version
=
3280 cpu_to_le32(POSIX_ACL_XATTR_VERSION
);
3281 data
= (char *)&dummy_acl
;
3282 data_len
= sizeof(dummy_acl
);
3286 ret
= get_cur_path(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
, p
);
3290 ret
= send_set_xattr(sctx
, p
, name
, name_len
, data
, data_len
);
3297 static int __process_deleted_xattr(int num
, struct btrfs_key
*di_key
,
3298 const char *name
, int name_len
,
3299 const char *data
, int data_len
,
3303 struct send_ctx
*sctx
= ctx
;
3306 p
= fs_path_alloc();
3310 ret
= get_cur_path(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
, p
);
3314 ret
= send_remove_xattr(sctx
, p
, name
, name_len
);
3321 static int process_new_xattr(struct send_ctx
*sctx
)
3325 ret
= iterate_dir_item(sctx
->send_root
, sctx
->left_path
,
3326 sctx
->cmp_key
, __process_new_xattr
, sctx
);
3331 static int process_deleted_xattr(struct send_ctx
*sctx
)
3335 ret
= iterate_dir_item(sctx
->parent_root
, sctx
->right_path
,
3336 sctx
->cmp_key
, __process_deleted_xattr
, sctx
);
3341 struct find_xattr_ctx
{
3349 static int __find_xattr(int num
, struct btrfs_key
*di_key
,
3350 const char *name
, int name_len
,
3351 const char *data
, int data_len
,
3352 u8 type
, void *vctx
)
3354 struct find_xattr_ctx
*ctx
= vctx
;
3356 if (name_len
== ctx
->name_len
&&
3357 strncmp(name
, ctx
->name
, name_len
) == 0) {
3358 ctx
->found_idx
= num
;
3359 ctx
->found_data_len
= data_len
;
3360 ctx
->found_data
= kmemdup(data
, data_len
, GFP_NOFS
);
3361 if (!ctx
->found_data
)
3368 static int find_xattr(struct btrfs_root
*root
,
3369 struct btrfs_path
*path
,
3370 struct btrfs_key
*key
,
3371 const char *name
, int name_len
,
3372 char **data
, int *data_len
)
3375 struct find_xattr_ctx ctx
;
3378 ctx
.name_len
= name_len
;
3380 ctx
.found_data
= NULL
;
3381 ctx
.found_data_len
= 0;
3383 ret
= iterate_dir_item(root
, path
, key
, __find_xattr
, &ctx
);
3387 if (ctx
.found_idx
== -1)
3390 *data
= ctx
.found_data
;
3391 *data_len
= ctx
.found_data_len
;
3393 kfree(ctx
.found_data
);
3395 return ctx
.found_idx
;
3399 static int __process_changed_new_xattr(int num
, struct btrfs_key
*di_key
,
3400 const char *name
, int name_len
,
3401 const char *data
, int data_len
,
3405 struct send_ctx
*sctx
= ctx
;
3406 char *found_data
= NULL
;
3407 int found_data_len
= 0;
3409 ret
= find_xattr(sctx
->parent_root
, sctx
->right_path
,
3410 sctx
->cmp_key
, name
, name_len
, &found_data
,
3412 if (ret
== -ENOENT
) {
3413 ret
= __process_new_xattr(num
, di_key
, name
, name_len
, data
,
3414 data_len
, type
, ctx
);
3415 } else if (ret
>= 0) {
3416 if (data_len
!= found_data_len
||
3417 memcmp(data
, found_data
, data_len
)) {
3418 ret
= __process_new_xattr(num
, di_key
, name
, name_len
,
3419 data
, data_len
, type
, ctx
);
3429 static int __process_changed_deleted_xattr(int num
, struct btrfs_key
*di_key
,
3430 const char *name
, int name_len
,
3431 const char *data
, int data_len
,
3435 struct send_ctx
*sctx
= ctx
;
3437 ret
= find_xattr(sctx
->send_root
, sctx
->left_path
, sctx
->cmp_key
,
3438 name
, name_len
, NULL
, NULL
);
3440 ret
= __process_deleted_xattr(num
, di_key
, name
, name_len
, data
,
3441 data_len
, type
, ctx
);
3448 static int process_changed_xattr(struct send_ctx
*sctx
)
3452 ret
= iterate_dir_item(sctx
->send_root
, sctx
->left_path
,
3453 sctx
->cmp_key
, __process_changed_new_xattr
, sctx
);
3456 ret
= iterate_dir_item(sctx
->parent_root
, sctx
->right_path
,
3457 sctx
->cmp_key
, __process_changed_deleted_xattr
, sctx
);
3463 static int process_all_new_xattrs(struct send_ctx
*sctx
)
3466 struct btrfs_root
*root
;
3467 struct btrfs_path
*path
;
3468 struct btrfs_key key
;
3469 struct btrfs_key found_key
;
3470 struct extent_buffer
*eb
;
3473 path
= alloc_path_for_send();
3477 root
= sctx
->send_root
;
3479 key
.objectid
= sctx
->cmp_key
->objectid
;
3480 key
.type
= BTRFS_XATTR_ITEM_KEY
;
3483 ret
= btrfs_search_slot_for_read(root
, &key
, path
, 1, 0);
3491 eb
= path
->nodes
[0];
3492 slot
= path
->slots
[0];
3493 btrfs_item_key_to_cpu(eb
, &found_key
, slot
);
3495 if (found_key
.objectid
!= key
.objectid
||
3496 found_key
.type
!= key
.type
) {
3501 ret
= iterate_dir_item(root
, path
, &found_key
,
3502 __process_new_xattr
, sctx
);
3506 btrfs_release_path(path
);
3507 key
.offset
= found_key
.offset
+ 1;
3511 btrfs_free_path(path
);
3515 static ssize_t
fill_read_buf(struct send_ctx
*sctx
, u64 offset
, u32 len
)
3517 struct btrfs_root
*root
= sctx
->send_root
;
3518 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
3519 struct inode
*inode
;
3522 struct btrfs_key key
;
3523 pgoff_t index
= offset
>> PAGE_CACHE_SHIFT
;
3525 unsigned pg_offset
= offset
& ~PAGE_CACHE_MASK
;
3528 key
.objectid
= sctx
->cur_ino
;
3529 key
.type
= BTRFS_INODE_ITEM_KEY
;
3532 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3534 return PTR_ERR(inode
);
3536 if (offset
+ len
> i_size_read(inode
)) {
3537 if (offset
> i_size_read(inode
))
3540 len
= offset
- i_size_read(inode
);
3545 last_index
= (offset
+ len
- 1) >> PAGE_CACHE_SHIFT
;
3546 while (index
<= last_index
) {
3547 unsigned cur_len
= min_t(unsigned, len
,
3548 PAGE_CACHE_SIZE
- pg_offset
);
3549 page
= find_or_create_page(inode
->i_mapping
, index
, GFP_NOFS
);
3555 if (!PageUptodate(page
)) {
3556 btrfs_readpage(NULL
, page
);
3558 if (!PageUptodate(page
)) {
3560 page_cache_release(page
);
3567 memcpy(sctx
->read_buf
+ ret
, addr
+ pg_offset
, cur_len
);
3570 page_cache_release(page
);
3582 * Read some bytes from the current inode/file and send a write command to
3585 static int send_write(struct send_ctx
*sctx
, u64 offset
, u32 len
)
3589 ssize_t num_read
= 0;
3591 p
= fs_path_alloc();
3595 verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset
, len
);
3597 num_read
= fill_read_buf(sctx
, offset
, len
);
3598 if (num_read
<= 0) {
3604 ret
= begin_cmd(sctx
, BTRFS_SEND_C_WRITE
);
3608 ret
= get_cur_path(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
, p
);
3612 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
3613 TLV_PUT_U64(sctx
, BTRFS_SEND_A_FILE_OFFSET
, offset
);
3614 TLV_PUT(sctx
, BTRFS_SEND_A_DATA
, sctx
->read_buf
, num_read
);
3616 ret
= send_cmd(sctx
);
3627 * Send a clone command to user space.
3629 static int send_clone(struct send_ctx
*sctx
,
3630 u64 offset
, u32 len
,
3631 struct clone_root
*clone_root
)
3637 verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, "
3638 "clone_inode=%llu, clone_offset=%llu\n", offset
, len
,
3639 clone_root
->root
->objectid
, clone_root
->ino
,
3640 clone_root
->offset
);
3642 p
= fs_path_alloc();
3646 ret
= begin_cmd(sctx
, BTRFS_SEND_C_CLONE
);
3650 ret
= get_cur_path(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
, p
);
3654 TLV_PUT_U64(sctx
, BTRFS_SEND_A_FILE_OFFSET
, offset
);
3655 TLV_PUT_U64(sctx
, BTRFS_SEND_A_CLONE_LEN
, len
);
3656 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
3658 if (clone_root
->root
== sctx
->send_root
) {
3659 ret
= get_inode_info(sctx
->send_root
, clone_root
->ino
, NULL
,
3660 &gen
, NULL
, NULL
, NULL
, NULL
);
3663 ret
= get_cur_path(sctx
, clone_root
->ino
, gen
, p
);
3665 ret
= get_inode_path(clone_root
->root
, clone_root
->ino
, p
);
3670 TLV_PUT_UUID(sctx
, BTRFS_SEND_A_CLONE_UUID
,
3671 clone_root
->root
->root_item
.uuid
);
3672 TLV_PUT_U64(sctx
, BTRFS_SEND_A_CLONE_CTRANSID
,
3673 le64_to_cpu(clone_root
->root
->root_item
.ctransid
));
3674 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_CLONE_PATH
, p
);
3675 TLV_PUT_U64(sctx
, BTRFS_SEND_A_CLONE_OFFSET
,
3676 clone_root
->offset
);
3678 ret
= send_cmd(sctx
);
3687 * Send an update extent command to user space.
3689 static int send_update_extent(struct send_ctx
*sctx
,
3690 u64 offset
, u32 len
)
3695 p
= fs_path_alloc();
3699 ret
= begin_cmd(sctx
, BTRFS_SEND_C_UPDATE_EXTENT
);
3703 ret
= get_cur_path(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
, p
);
3707 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
3708 TLV_PUT_U64(sctx
, BTRFS_SEND_A_FILE_OFFSET
, offset
);
3709 TLV_PUT_U64(sctx
, BTRFS_SEND_A_SIZE
, len
);
3711 ret
= send_cmd(sctx
);
3719 static int send_hole(struct send_ctx
*sctx
, u64 end
)
3721 struct fs_path
*p
= NULL
;
3722 u64 offset
= sctx
->cur_inode_last_extent
;
3726 p
= fs_path_alloc();
3729 memset(sctx
->read_buf
, 0, BTRFS_SEND_READ_SIZE
);
3730 while (offset
< end
) {
3731 len
= min_t(u64
, end
- offset
, BTRFS_SEND_READ_SIZE
);
3733 ret
= begin_cmd(sctx
, BTRFS_SEND_C_WRITE
);
3736 ret
= get_cur_path(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
, p
);
3739 TLV_PUT_PATH(sctx
, BTRFS_SEND_A_PATH
, p
);
3740 TLV_PUT_U64(sctx
, BTRFS_SEND_A_FILE_OFFSET
, offset
);
3741 TLV_PUT(sctx
, BTRFS_SEND_A_DATA
, sctx
->read_buf
, len
);
3742 ret
= send_cmd(sctx
);
3752 static int send_write_or_clone(struct send_ctx
*sctx
,
3753 struct btrfs_path
*path
,
3754 struct btrfs_key
*key
,
3755 struct clone_root
*clone_root
)
3758 struct btrfs_file_extent_item
*ei
;
3759 u64 offset
= key
->offset
;
3765 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3766 struct btrfs_file_extent_item
);
3767 type
= btrfs_file_extent_type(path
->nodes
[0], ei
);
3768 if (type
== BTRFS_FILE_EXTENT_INLINE
) {
3769 len
= btrfs_file_extent_inline_len(path
->nodes
[0], ei
);
3771 * it is possible the inline item won't cover the whole page,
3772 * but there may be items after this page. Make
3773 * sure to send the whole thing
3775 len
= PAGE_CACHE_ALIGN(len
);
3777 len
= btrfs_file_extent_num_bytes(path
->nodes
[0], ei
);
3780 if (offset
+ len
> sctx
->cur_inode_size
)
3781 len
= sctx
->cur_inode_size
- offset
;
3788 ret
= send_clone(sctx
, offset
, len
, clone_root
);
3789 } else if (sctx
->flags
& BTRFS_SEND_FLAG_NO_FILE_DATA
) {
3790 ret
= send_update_extent(sctx
, offset
, len
);
3794 if (l
> BTRFS_SEND_READ_SIZE
)
3795 l
= BTRFS_SEND_READ_SIZE
;
3796 ret
= send_write(sctx
, pos
+ offset
, l
);
3809 static int is_extent_unchanged(struct send_ctx
*sctx
,
3810 struct btrfs_path
*left_path
,
3811 struct btrfs_key
*ekey
)
3814 struct btrfs_key key
;
3815 struct btrfs_path
*path
= NULL
;
3816 struct extent_buffer
*eb
;
3818 struct btrfs_key found_key
;
3819 struct btrfs_file_extent_item
*ei
;
3824 u64 left_offset_fixed
;
3832 path
= alloc_path_for_send();
3836 eb
= left_path
->nodes
[0];
3837 slot
= left_path
->slots
[0];
3838 ei
= btrfs_item_ptr(eb
, slot
, struct btrfs_file_extent_item
);
3839 left_type
= btrfs_file_extent_type(eb
, ei
);
3841 if (left_type
!= BTRFS_FILE_EXTENT_REG
) {
3845 left_disknr
= btrfs_file_extent_disk_bytenr(eb
, ei
);
3846 left_len
= btrfs_file_extent_num_bytes(eb
, ei
);
3847 left_offset
= btrfs_file_extent_offset(eb
, ei
);
3848 left_gen
= btrfs_file_extent_generation(eb
, ei
);
3851 * Following comments will refer to these graphics. L is the left
3852 * extents which we are checking at the moment. 1-8 are the right
3853 * extents that we iterate.
3856 * |-1-|-2a-|-3-|-4-|-5-|-6-|
3859 * |--1--|-2b-|...(same as above)
3861 * Alternative situation. Happens on files where extents got split.
3863 * |-----------7-----------|-6-|
3865 * Alternative situation. Happens on files which got larger.
3868 * Nothing follows after 8.
3871 key
.objectid
= ekey
->objectid
;
3872 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3873 key
.offset
= ekey
->offset
;
3874 ret
= btrfs_search_slot_for_read(sctx
->parent_root
, &key
, path
, 0, 0);
3883 * Handle special case where the right side has no extents at all.
3885 eb
= path
->nodes
[0];
3886 slot
= path
->slots
[0];
3887 btrfs_item_key_to_cpu(eb
, &found_key
, slot
);
3888 if (found_key
.objectid
!= key
.objectid
||
3889 found_key
.type
!= key
.type
) {
3890 /* If we're a hole then just pretend nothing changed */
3891 ret
= (left_disknr
) ? 0 : 1;
3896 * We're now on 2a, 2b or 7.
3899 while (key
.offset
< ekey
->offset
+ left_len
) {
3900 ei
= btrfs_item_ptr(eb
, slot
, struct btrfs_file_extent_item
);
3901 right_type
= btrfs_file_extent_type(eb
, ei
);
3902 if (right_type
!= BTRFS_FILE_EXTENT_REG
) {
3907 right_disknr
= btrfs_file_extent_disk_bytenr(eb
, ei
);
3908 right_len
= btrfs_file_extent_num_bytes(eb
, ei
);
3909 right_offset
= btrfs_file_extent_offset(eb
, ei
);
3910 right_gen
= btrfs_file_extent_generation(eb
, ei
);
3913 * Are we at extent 8? If yes, we know the extent is changed.
3914 * This may only happen on the first iteration.
3916 if (found_key
.offset
+ right_len
<= ekey
->offset
) {
3917 /* If we're a hole just pretend nothing changed */
3918 ret
= (left_disknr
) ? 0 : 1;
3922 left_offset_fixed
= left_offset
;
3923 if (key
.offset
< ekey
->offset
) {
3924 /* Fix the right offset for 2a and 7. */
3925 right_offset
+= ekey
->offset
- key
.offset
;
3927 /* Fix the left offset for all behind 2a and 2b */
3928 left_offset_fixed
+= key
.offset
- ekey
->offset
;
3932 * Check if we have the same extent.
3934 if (left_disknr
!= right_disknr
||
3935 left_offset_fixed
!= right_offset
||
3936 left_gen
!= right_gen
) {
3942 * Go to the next extent.
3944 ret
= btrfs_next_item(sctx
->parent_root
, path
);
3948 eb
= path
->nodes
[0];
3949 slot
= path
->slots
[0];
3950 btrfs_item_key_to_cpu(eb
, &found_key
, slot
);
3952 if (ret
|| found_key
.objectid
!= key
.objectid
||
3953 found_key
.type
!= key
.type
) {
3954 key
.offset
+= right_len
;
3957 if (found_key
.offset
!= key
.offset
+ right_len
) {
3965 * We're now behind the left extent (treat as unchanged) or at the end
3966 * of the right side (treat as changed).
3968 if (key
.offset
>= ekey
->offset
+ left_len
)
3975 btrfs_free_path(path
);
3979 static int get_last_extent(struct send_ctx
*sctx
, u64 offset
)
3981 struct btrfs_path
*path
;
3982 struct btrfs_root
*root
= sctx
->send_root
;
3983 struct btrfs_file_extent_item
*fi
;
3984 struct btrfs_key key
;
3989 path
= alloc_path_for_send();
3993 sctx
->cur_inode_last_extent
= 0;
3995 key
.objectid
= sctx
->cur_ino
;
3996 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3997 key
.offset
= offset
;
3998 ret
= btrfs_search_slot_for_read(root
, &key
, path
, 0, 1);
4002 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, path
->slots
[0]);
4003 if (key
.objectid
!= sctx
->cur_ino
|| key
.type
!= BTRFS_EXTENT_DATA_KEY
)
4006 fi
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4007 struct btrfs_file_extent_item
);
4008 type
= btrfs_file_extent_type(path
->nodes
[0], fi
);
4009 if (type
== BTRFS_FILE_EXTENT_INLINE
) {
4010 u64 size
= btrfs_file_extent_inline_len(path
->nodes
[0], fi
);
4011 extent_end
= ALIGN(key
.offset
+ size
,
4012 sctx
->send_root
->sectorsize
);
4014 extent_end
= key
.offset
+
4015 btrfs_file_extent_num_bytes(path
->nodes
[0], fi
);
4017 sctx
->cur_inode_last_extent
= extent_end
;
4019 btrfs_free_path(path
);
4023 static int maybe_send_hole(struct send_ctx
*sctx
, struct btrfs_path
*path
,
4024 struct btrfs_key
*key
)
4026 struct btrfs_file_extent_item
*fi
;
4031 if (sctx
->cur_ino
!= key
->objectid
|| !need_send_hole(sctx
))
4034 if (sctx
->cur_inode_last_extent
== (u64
)-1) {
4035 ret
= get_last_extent(sctx
, key
->offset
- 1);
4040 fi
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4041 struct btrfs_file_extent_item
);
4042 type
= btrfs_file_extent_type(path
->nodes
[0], fi
);
4043 if (type
== BTRFS_FILE_EXTENT_INLINE
) {
4044 u64 size
= btrfs_file_extent_inline_len(path
->nodes
[0], fi
);
4045 extent_end
= ALIGN(key
->offset
+ size
,
4046 sctx
->send_root
->sectorsize
);
4048 extent_end
= key
->offset
+
4049 btrfs_file_extent_num_bytes(path
->nodes
[0], fi
);
4051 if (sctx
->cur_inode_last_extent
< key
->offset
)
4052 ret
= send_hole(sctx
, key
->offset
);
4053 sctx
->cur_inode_last_extent
= extent_end
;
4057 static int process_extent(struct send_ctx
*sctx
,
4058 struct btrfs_path
*path
,
4059 struct btrfs_key
*key
)
4061 struct clone_root
*found_clone
= NULL
;
4064 if (S_ISLNK(sctx
->cur_inode_mode
))
4067 if (sctx
->parent_root
&& !sctx
->cur_inode_new
) {
4068 ret
= is_extent_unchanged(sctx
, path
, key
);
4076 struct btrfs_file_extent_item
*ei
;
4079 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4080 struct btrfs_file_extent_item
);
4081 type
= btrfs_file_extent_type(path
->nodes
[0], ei
);
4082 if (type
== BTRFS_FILE_EXTENT_PREALLOC
||
4083 type
== BTRFS_FILE_EXTENT_REG
) {
4085 * The send spec does not have a prealloc command yet,
4086 * so just leave a hole for prealloc'ed extents until
4087 * we have enough commands queued up to justify rev'ing
4090 if (type
== BTRFS_FILE_EXTENT_PREALLOC
) {
4095 /* Have a hole, just skip it. */
4096 if (btrfs_file_extent_disk_bytenr(path
->nodes
[0], ei
) == 0) {
4103 ret
= find_extent_clone(sctx
, path
, key
->objectid
, key
->offset
,
4104 sctx
->cur_inode_size
, &found_clone
);
4105 if (ret
!= -ENOENT
&& ret
< 0)
4108 ret
= send_write_or_clone(sctx
, path
, key
, found_clone
);
4112 ret
= maybe_send_hole(sctx
, path
, key
);
4117 static int process_all_extents(struct send_ctx
*sctx
)
4120 struct btrfs_root
*root
;
4121 struct btrfs_path
*path
;
4122 struct btrfs_key key
;
4123 struct btrfs_key found_key
;
4124 struct extent_buffer
*eb
;
4127 root
= sctx
->send_root
;
4128 path
= alloc_path_for_send();
4132 key
.objectid
= sctx
->cmp_key
->objectid
;
4133 key
.type
= BTRFS_EXTENT_DATA_KEY
;
4136 ret
= btrfs_search_slot_for_read(root
, &key
, path
, 1, 0);
4144 eb
= path
->nodes
[0];
4145 slot
= path
->slots
[0];
4146 btrfs_item_key_to_cpu(eb
, &found_key
, slot
);
4148 if (found_key
.objectid
!= key
.objectid
||
4149 found_key
.type
!= key
.type
) {
4154 ret
= process_extent(sctx
, path
, &found_key
);
4158 btrfs_release_path(path
);
4159 key
.offset
= found_key
.offset
+ 1;
4163 btrfs_free_path(path
);
4167 static int process_recorded_refs_if_needed(struct send_ctx
*sctx
, int at_end
)
4171 if (sctx
->cur_ino
== 0)
4173 if (!at_end
&& sctx
->cur_ino
== sctx
->cmp_key
->objectid
&&
4174 sctx
->cmp_key
->type
<= BTRFS_INODE_EXTREF_KEY
)
4176 if (list_empty(&sctx
->new_refs
) && list_empty(&sctx
->deleted_refs
))
4179 ret
= process_recorded_refs(sctx
);
4184 * We have processed the refs and thus need to advance send_progress.
4185 * Now, calls to get_cur_xxx will take the updated refs of the current
4186 * inode into account.
4188 sctx
->send_progress
= sctx
->cur_ino
+ 1;
4194 static int finish_inode_if_needed(struct send_ctx
*sctx
, int at_end
)
4206 ret
= process_recorded_refs_if_needed(sctx
, at_end
);
4210 if (sctx
->cur_ino
== 0 || sctx
->cur_inode_deleted
)
4212 if (!at_end
&& sctx
->cmp_key
->objectid
== sctx
->cur_ino
)
4215 ret
= get_inode_info(sctx
->send_root
, sctx
->cur_ino
, NULL
, NULL
,
4216 &left_mode
, &left_uid
, &left_gid
, NULL
);
4220 if (!sctx
->parent_root
|| sctx
->cur_inode_new
) {
4222 if (!S_ISLNK(sctx
->cur_inode_mode
))
4225 ret
= get_inode_info(sctx
->parent_root
, sctx
->cur_ino
,
4226 NULL
, NULL
, &right_mode
, &right_uid
,
4231 if (left_uid
!= right_uid
|| left_gid
!= right_gid
)
4233 if (!S_ISLNK(sctx
->cur_inode_mode
) && left_mode
!= right_mode
)
4237 if (S_ISREG(sctx
->cur_inode_mode
)) {
4238 if (need_send_hole(sctx
)) {
4239 if (sctx
->cur_inode_last_extent
== (u64
)-1) {
4240 ret
= get_last_extent(sctx
, (u64
)-1);
4244 if (sctx
->cur_inode_last_extent
<
4245 sctx
->cur_inode_size
) {
4246 ret
= send_hole(sctx
, sctx
->cur_inode_size
);
4251 ret
= send_truncate(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
,
4252 sctx
->cur_inode_size
);
4258 ret
= send_chown(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
,
4259 left_uid
, left_gid
);
4264 ret
= send_chmod(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
,
4271 * Need to send that every time, no matter if it actually changed
4272 * between the two trees as we have done changes to the inode before.
4274 ret
= send_utimes(sctx
, sctx
->cur_ino
, sctx
->cur_inode_gen
);
4282 static int changed_inode(struct send_ctx
*sctx
,
4283 enum btrfs_compare_tree_result result
)
4286 struct btrfs_key
*key
= sctx
->cmp_key
;
4287 struct btrfs_inode_item
*left_ii
= NULL
;
4288 struct btrfs_inode_item
*right_ii
= NULL
;
4292 sctx
->cur_ino
= key
->objectid
;
4293 sctx
->cur_inode_new_gen
= 0;
4294 sctx
->cur_inode_last_extent
= (u64
)-1;
4297 * Set send_progress to current inode. This will tell all get_cur_xxx
4298 * functions that the current inode's refs are not updated yet. Later,
4299 * when process_recorded_refs is finished, it is set to cur_ino + 1.
4301 sctx
->send_progress
= sctx
->cur_ino
;
4303 if (result
== BTRFS_COMPARE_TREE_NEW
||
4304 result
== BTRFS_COMPARE_TREE_CHANGED
) {
4305 left_ii
= btrfs_item_ptr(sctx
->left_path
->nodes
[0],
4306 sctx
->left_path
->slots
[0],
4307 struct btrfs_inode_item
);
4308 left_gen
= btrfs_inode_generation(sctx
->left_path
->nodes
[0],
4311 right_ii
= btrfs_item_ptr(sctx
->right_path
->nodes
[0],
4312 sctx
->right_path
->slots
[0],
4313 struct btrfs_inode_item
);
4314 right_gen
= btrfs_inode_generation(sctx
->right_path
->nodes
[0],
4317 if (result
== BTRFS_COMPARE_TREE_CHANGED
) {
4318 right_ii
= btrfs_item_ptr(sctx
->right_path
->nodes
[0],
4319 sctx
->right_path
->slots
[0],
4320 struct btrfs_inode_item
);
4322 right_gen
= btrfs_inode_generation(sctx
->right_path
->nodes
[0],
4326 * The cur_ino = root dir case is special here. We can't treat
4327 * the inode as deleted+reused because it would generate a
4328 * stream that tries to delete/mkdir the root dir.
4330 if (left_gen
!= right_gen
&&
4331 sctx
->cur_ino
!= BTRFS_FIRST_FREE_OBJECTID
)
4332 sctx
->cur_inode_new_gen
= 1;
4335 if (result
== BTRFS_COMPARE_TREE_NEW
) {
4336 sctx
->cur_inode_gen
= left_gen
;
4337 sctx
->cur_inode_new
= 1;
4338 sctx
->cur_inode_deleted
= 0;
4339 sctx
->cur_inode_size
= btrfs_inode_size(
4340 sctx
->left_path
->nodes
[0], left_ii
);
4341 sctx
->cur_inode_mode
= btrfs_inode_mode(
4342 sctx
->left_path
->nodes
[0], left_ii
);
4343 if (sctx
->cur_ino
!= BTRFS_FIRST_FREE_OBJECTID
)
4344 ret
= send_create_inode_if_needed(sctx
);
4345 } else if (result
== BTRFS_COMPARE_TREE_DELETED
) {
4346 sctx
->cur_inode_gen
= right_gen
;
4347 sctx
->cur_inode_new
= 0;
4348 sctx
->cur_inode_deleted
= 1;
4349 sctx
->cur_inode_size
= btrfs_inode_size(
4350 sctx
->right_path
->nodes
[0], right_ii
);
4351 sctx
->cur_inode_mode
= btrfs_inode_mode(
4352 sctx
->right_path
->nodes
[0], right_ii
);
4353 } else if (result
== BTRFS_COMPARE_TREE_CHANGED
) {
4355 * We need to do some special handling in case the inode was
4356 * reported as changed with a changed generation number. This
4357 * means that the original inode was deleted and new inode
4358 * reused the same inum. So we have to treat the old inode as
4359 * deleted and the new one as new.
4361 if (sctx
->cur_inode_new_gen
) {
4363 * First, process the inode as if it was deleted.
4365 sctx
->cur_inode_gen
= right_gen
;
4366 sctx
->cur_inode_new
= 0;
4367 sctx
->cur_inode_deleted
= 1;
4368 sctx
->cur_inode_size
= btrfs_inode_size(
4369 sctx
->right_path
->nodes
[0], right_ii
);
4370 sctx
->cur_inode_mode
= btrfs_inode_mode(
4371 sctx
->right_path
->nodes
[0], right_ii
);
4372 ret
= process_all_refs(sctx
,
4373 BTRFS_COMPARE_TREE_DELETED
);
4378 * Now process the inode as if it was new.
4380 sctx
->cur_inode_gen
= left_gen
;
4381 sctx
->cur_inode_new
= 1;
4382 sctx
->cur_inode_deleted
= 0;
4383 sctx
->cur_inode_size
= btrfs_inode_size(
4384 sctx
->left_path
->nodes
[0], left_ii
);
4385 sctx
->cur_inode_mode
= btrfs_inode_mode(
4386 sctx
->left_path
->nodes
[0], left_ii
);
4387 ret
= send_create_inode_if_needed(sctx
);
4391 ret
= process_all_refs(sctx
, BTRFS_COMPARE_TREE_NEW
);
4395 * Advance send_progress now as we did not get into
4396 * process_recorded_refs_if_needed in the new_gen case.
4398 sctx
->send_progress
= sctx
->cur_ino
+ 1;
4401 * Now process all extents and xattrs of the inode as if
4402 * they were all new.
4404 ret
= process_all_extents(sctx
);
4407 ret
= process_all_new_xattrs(sctx
);
4411 sctx
->cur_inode_gen
= left_gen
;
4412 sctx
->cur_inode_new
= 0;
4413 sctx
->cur_inode_new_gen
= 0;
4414 sctx
->cur_inode_deleted
= 0;
4415 sctx
->cur_inode_size
= btrfs_inode_size(
4416 sctx
->left_path
->nodes
[0], left_ii
);
4417 sctx
->cur_inode_mode
= btrfs_inode_mode(
4418 sctx
->left_path
->nodes
[0], left_ii
);
4427 * We have to process new refs before deleted refs, but compare_trees gives us
4428 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
4429 * first and later process them in process_recorded_refs.
4430 * For the cur_inode_new_gen case, we skip recording completely because
4431 * changed_inode did already initiate processing of refs. The reason for this is
4432 * that in this case, compare_tree actually compares the refs of 2 different
4433 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
4434 * refs of the right tree as deleted and all refs of the left tree as new.
4436 static int changed_ref(struct send_ctx
*sctx
,
4437 enum btrfs_compare_tree_result result
)
4441 BUG_ON(sctx
->cur_ino
!= sctx
->cmp_key
->objectid
);
4443 if (!sctx
->cur_inode_new_gen
&&
4444 sctx
->cur_ino
!= BTRFS_FIRST_FREE_OBJECTID
) {
4445 if (result
== BTRFS_COMPARE_TREE_NEW
)
4446 ret
= record_new_ref(sctx
);
4447 else if (result
== BTRFS_COMPARE_TREE_DELETED
)
4448 ret
= record_deleted_ref(sctx
);
4449 else if (result
== BTRFS_COMPARE_TREE_CHANGED
)
4450 ret
= record_changed_ref(sctx
);
4457 * Process new/deleted/changed xattrs. We skip processing in the
4458 * cur_inode_new_gen case because changed_inode did already initiate processing
4459 * of xattrs. The reason is the same as in changed_ref
4461 static int changed_xattr(struct send_ctx
*sctx
,
4462 enum btrfs_compare_tree_result result
)
4466 BUG_ON(sctx
->cur_ino
!= sctx
->cmp_key
->objectid
);
4468 if (!sctx
->cur_inode_new_gen
&& !sctx
->cur_inode_deleted
) {
4469 if (result
== BTRFS_COMPARE_TREE_NEW
)
4470 ret
= process_new_xattr(sctx
);
4471 else if (result
== BTRFS_COMPARE_TREE_DELETED
)
4472 ret
= process_deleted_xattr(sctx
);
4473 else if (result
== BTRFS_COMPARE_TREE_CHANGED
)
4474 ret
= process_changed_xattr(sctx
);
4481 * Process new/deleted/changed extents. We skip processing in the
4482 * cur_inode_new_gen case because changed_inode did already initiate processing
4483 * of extents. The reason is the same as in changed_ref
4485 static int changed_extent(struct send_ctx
*sctx
,
4486 enum btrfs_compare_tree_result result
)
4490 BUG_ON(sctx
->cur_ino
!= sctx
->cmp_key
->objectid
);
4492 if (!sctx
->cur_inode_new_gen
&& !sctx
->cur_inode_deleted
) {
4493 if (result
!= BTRFS_COMPARE_TREE_DELETED
)
4494 ret
= process_extent(sctx
, sctx
->left_path
,
4501 static int dir_changed(struct send_ctx
*sctx
, u64 dir
)
4503 u64 orig_gen
, new_gen
;
4506 ret
= get_inode_info(sctx
->send_root
, dir
, NULL
, &new_gen
, NULL
, NULL
,
4511 ret
= get_inode_info(sctx
->parent_root
, dir
, NULL
, &orig_gen
, NULL
,
4516 return (orig_gen
!= new_gen
) ? 1 : 0;
4519 static int compare_refs(struct send_ctx
*sctx
, struct btrfs_path
*path
,
4520 struct btrfs_key
*key
)
4522 struct btrfs_inode_extref
*extref
;
4523 struct extent_buffer
*leaf
;
4524 u64 dirid
= 0, last_dirid
= 0;
4531 /* Easy case, just check this one dirid */
4532 if (key
->type
== BTRFS_INODE_REF_KEY
) {
4533 dirid
= key
->offset
;
4535 ret
= dir_changed(sctx
, dirid
);
4539 leaf
= path
->nodes
[0];
4540 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
4541 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
4542 while (cur_offset
< item_size
) {
4543 extref
= (struct btrfs_inode_extref
*)(ptr
+
4545 dirid
= btrfs_inode_extref_parent(leaf
, extref
);
4546 ref_name_len
= btrfs_inode_extref_name_len(leaf
, extref
);
4547 cur_offset
+= ref_name_len
+ sizeof(*extref
);
4548 if (dirid
== last_dirid
)
4550 ret
= dir_changed(sctx
, dirid
);
4560 * Updates compare related fields in sctx and simply forwards to the actual
4561 * changed_xxx functions.
4563 static int changed_cb(struct btrfs_root
*left_root
,
4564 struct btrfs_root
*right_root
,
4565 struct btrfs_path
*left_path
,
4566 struct btrfs_path
*right_path
,
4567 struct btrfs_key
*key
,
4568 enum btrfs_compare_tree_result result
,
4572 struct send_ctx
*sctx
= ctx
;
4574 if (result
== BTRFS_COMPARE_TREE_SAME
) {
4575 if (key
->type
== BTRFS_INODE_REF_KEY
||
4576 key
->type
== BTRFS_INODE_EXTREF_KEY
) {
4577 ret
= compare_refs(sctx
, left_path
, key
);
4582 } else if (key
->type
== BTRFS_EXTENT_DATA_KEY
) {
4583 return maybe_send_hole(sctx
, left_path
, key
);
4587 result
= BTRFS_COMPARE_TREE_CHANGED
;
4591 sctx
->left_path
= left_path
;
4592 sctx
->right_path
= right_path
;
4593 sctx
->cmp_key
= key
;
4595 ret
= finish_inode_if_needed(sctx
, 0);
4599 /* Ignore non-FS objects */
4600 if (key
->objectid
== BTRFS_FREE_INO_OBJECTID
||
4601 key
->objectid
== BTRFS_FREE_SPACE_OBJECTID
)
4604 if (key
->type
== BTRFS_INODE_ITEM_KEY
)
4605 ret
= changed_inode(sctx
, result
);
4606 else if (key
->type
== BTRFS_INODE_REF_KEY
||
4607 key
->type
== BTRFS_INODE_EXTREF_KEY
)
4608 ret
= changed_ref(sctx
, result
);
4609 else if (key
->type
== BTRFS_XATTR_ITEM_KEY
)
4610 ret
= changed_xattr(sctx
, result
);
4611 else if (key
->type
== BTRFS_EXTENT_DATA_KEY
)
4612 ret
= changed_extent(sctx
, result
);
4618 static int full_send_tree(struct send_ctx
*sctx
)
4621 struct btrfs_trans_handle
*trans
= NULL
;
4622 struct btrfs_root
*send_root
= sctx
->send_root
;
4623 struct btrfs_key key
;
4624 struct btrfs_key found_key
;
4625 struct btrfs_path
*path
;
4626 struct extent_buffer
*eb
;
4631 path
= alloc_path_for_send();
4635 spin_lock(&send_root
->root_item_lock
);
4636 start_ctransid
= btrfs_root_ctransid(&send_root
->root_item
);
4637 spin_unlock(&send_root
->root_item_lock
);
4639 key
.objectid
= BTRFS_FIRST_FREE_OBJECTID
;
4640 key
.type
= BTRFS_INODE_ITEM_KEY
;
4645 * We need to make sure the transaction does not get committed
4646 * while we do anything on commit roots. Join a transaction to prevent
4649 trans
= btrfs_join_transaction(send_root
);
4650 if (IS_ERR(trans
)) {
4651 ret
= PTR_ERR(trans
);
4657 * Make sure the tree has not changed after re-joining. We detect this
4658 * by comparing start_ctransid and ctransid. They should always match.
4660 spin_lock(&send_root
->root_item_lock
);
4661 ctransid
= btrfs_root_ctransid(&send_root
->root_item
);
4662 spin_unlock(&send_root
->root_item_lock
);
4664 if (ctransid
!= start_ctransid
) {
4665 WARN(1, KERN_WARNING
"btrfs: the root that you're trying to "
4666 "send was modified in between. This is "
4667 "probably a bug.\n");
4672 ret
= btrfs_search_slot_for_read(send_root
, &key
, path
, 1, 0);
4680 * When someone want to commit while we iterate, end the
4681 * joined transaction and rejoin.
4683 if (btrfs_should_end_transaction(trans
, send_root
)) {
4684 ret
= btrfs_end_transaction(trans
, send_root
);
4688 btrfs_release_path(path
);
4692 eb
= path
->nodes
[0];
4693 slot
= path
->slots
[0];
4694 btrfs_item_key_to_cpu(eb
, &found_key
, slot
);
4696 ret
= changed_cb(send_root
, NULL
, path
, NULL
,
4697 &found_key
, BTRFS_COMPARE_TREE_NEW
, sctx
);
4701 key
.objectid
= found_key
.objectid
;
4702 key
.type
= found_key
.type
;
4703 key
.offset
= found_key
.offset
+ 1;
4705 ret
= btrfs_next_item(send_root
, path
);
4715 ret
= finish_inode_if_needed(sctx
, 1);
4718 btrfs_free_path(path
);
4721 ret
= btrfs_end_transaction(trans
, send_root
);
4723 btrfs_end_transaction(trans
, send_root
);
4728 static int send_subvol(struct send_ctx
*sctx
)
4732 if (!(sctx
->flags
& BTRFS_SEND_FLAG_OMIT_STREAM_HEADER
)) {
4733 ret
= send_header(sctx
);
4738 ret
= send_subvol_begin(sctx
);
4742 if (sctx
->parent_root
) {
4743 ret
= btrfs_compare_trees(sctx
->send_root
, sctx
->parent_root
,
4747 ret
= finish_inode_if_needed(sctx
, 1);
4751 ret
= full_send_tree(sctx
);
4757 free_recorded_refs(sctx
);
4761 long btrfs_ioctl_send(struct file
*mnt_file
, void __user
*arg_
)
4764 struct btrfs_root
*send_root
;
4765 struct btrfs_root
*clone_root
;
4766 struct btrfs_fs_info
*fs_info
;
4767 struct btrfs_ioctl_send_args
*arg
= NULL
;
4768 struct btrfs_key key
;
4769 struct send_ctx
*sctx
= NULL
;
4771 u64
*clone_sources_tmp
= NULL
;
4772 int clone_sources_to_rollback
= 0;
4774 if (!capable(CAP_SYS_ADMIN
))
4777 send_root
= BTRFS_I(file_inode(mnt_file
))->root
;
4778 fs_info
= send_root
->fs_info
;
4781 * The subvolume must remain read-only during send, protect against
4784 spin_lock(&send_root
->root_item_lock
);
4785 send_root
->send_in_progress
++;
4786 spin_unlock(&send_root
->root_item_lock
);
4789 * This is done when we lookup the root, it should already be complete
4790 * by the time we get here.
4792 WARN_ON(send_root
->orphan_cleanup_state
!= ORPHAN_CLEANUP_DONE
);
4795 * If we just created this root we need to make sure that the orphan
4796 * cleanup has been done and committed since we search the commit root,
4797 * so check its commit root transid with our otransid and if they match
4798 * commit the transaction to make sure everything is updated.
4800 down_read(&send_root
->fs_info
->extent_commit_sem
);
4801 if (btrfs_header_generation(send_root
->commit_root
) ==
4802 btrfs_root_otransid(&send_root
->root_item
)) {
4803 struct btrfs_trans_handle
*trans
;
4805 up_read(&send_root
->fs_info
->extent_commit_sem
);
4807 trans
= btrfs_attach_transaction_barrier(send_root
);
4808 if (IS_ERR(trans
)) {
4809 if (PTR_ERR(trans
) != -ENOENT
) {
4810 ret
= PTR_ERR(trans
);
4813 /* ENOENT means theres no transaction */
4815 ret
= btrfs_commit_transaction(trans
, send_root
);
4820 up_read(&send_root
->fs_info
->extent_commit_sem
);
4824 * Userspace tools do the checks and warn the user if it's
4827 if (!btrfs_root_readonly(send_root
)) {
4832 arg
= memdup_user(arg_
, sizeof(*arg
));
4839 if (!access_ok(VERIFY_READ
, arg
->clone_sources
,
4840 sizeof(*arg
->clone_sources
) *
4841 arg
->clone_sources_count
)) {
4846 if (arg
->flags
& ~BTRFS_SEND_FLAG_MASK
) {
4851 sctx
= kzalloc(sizeof(struct send_ctx
), GFP_NOFS
);
4857 INIT_LIST_HEAD(&sctx
->new_refs
);
4858 INIT_LIST_HEAD(&sctx
->deleted_refs
);
4859 INIT_RADIX_TREE(&sctx
->name_cache
, GFP_NOFS
);
4860 INIT_LIST_HEAD(&sctx
->name_cache_list
);
4862 sctx
->flags
= arg
->flags
;
4864 sctx
->send_filp
= fget(arg
->send_fd
);
4865 if (!sctx
->send_filp
) {
4870 sctx
->send_root
= send_root
;
4871 sctx
->clone_roots_cnt
= arg
->clone_sources_count
;
4873 sctx
->send_max_size
= BTRFS_SEND_BUF_SIZE
;
4874 sctx
->send_buf
= vmalloc(sctx
->send_max_size
);
4875 if (!sctx
->send_buf
) {
4880 sctx
->read_buf
= vmalloc(BTRFS_SEND_READ_SIZE
);
4881 if (!sctx
->read_buf
) {
4886 sctx
->clone_roots
= vzalloc(sizeof(struct clone_root
) *
4887 (arg
->clone_sources_count
+ 1));
4888 if (!sctx
->clone_roots
) {
4893 if (arg
->clone_sources_count
) {
4894 clone_sources_tmp
= vmalloc(arg
->clone_sources_count
*
4895 sizeof(*arg
->clone_sources
));
4896 if (!clone_sources_tmp
) {
4901 ret
= copy_from_user(clone_sources_tmp
, arg
->clone_sources
,
4902 arg
->clone_sources_count
*
4903 sizeof(*arg
->clone_sources
));
4909 for (i
= 0; i
< arg
->clone_sources_count
; i
++) {
4910 key
.objectid
= clone_sources_tmp
[i
];
4911 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4912 key
.offset
= (u64
)-1;
4913 clone_root
= btrfs_read_fs_root_no_name(fs_info
, &key
);
4914 if (IS_ERR(clone_root
)) {
4915 ret
= PTR_ERR(clone_root
);
4918 clone_sources_to_rollback
= i
+ 1;
4919 spin_lock(&clone_root
->root_item_lock
);
4920 clone_root
->send_in_progress
++;
4921 if (!btrfs_root_readonly(clone_root
)) {
4922 spin_unlock(&clone_root
->root_item_lock
);
4926 spin_unlock(&clone_root
->root_item_lock
);
4927 sctx
->clone_roots
[i
].root
= clone_root
;
4929 vfree(clone_sources_tmp
);
4930 clone_sources_tmp
= NULL
;
4933 if (arg
->parent_root
) {
4934 key
.objectid
= arg
->parent_root
;
4935 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4936 key
.offset
= (u64
)-1;
4937 sctx
->parent_root
= btrfs_read_fs_root_no_name(fs_info
, &key
);
4938 if (IS_ERR(sctx
->parent_root
)) {
4939 ret
= PTR_ERR(sctx
->parent_root
);
4942 spin_lock(&sctx
->parent_root
->root_item_lock
);
4943 sctx
->parent_root
->send_in_progress
++;
4944 if (!btrfs_root_readonly(sctx
->parent_root
)) {
4945 spin_unlock(&sctx
->parent_root
->root_item_lock
);
4949 spin_unlock(&sctx
->parent_root
->root_item_lock
);
4953 * Clones from send_root are allowed, but only if the clone source
4954 * is behind the current send position. This is checked while searching
4955 * for possible clone sources.
4957 sctx
->clone_roots
[sctx
->clone_roots_cnt
++].root
= sctx
->send_root
;
4959 /* We do a bsearch later */
4960 sort(sctx
->clone_roots
, sctx
->clone_roots_cnt
,
4961 sizeof(*sctx
->clone_roots
), __clone_root_cmp_sort
,
4964 ret
= send_subvol(sctx
);
4968 if (!(sctx
->flags
& BTRFS_SEND_FLAG_OMIT_END_CMD
)) {
4969 ret
= begin_cmd(sctx
, BTRFS_SEND_C_END
);
4972 ret
= send_cmd(sctx
);
4978 for (i
= 0; sctx
&& i
< clone_sources_to_rollback
; i
++) {
4979 struct btrfs_root
*r
= sctx
->clone_roots
[i
].root
;
4981 spin_lock(&r
->root_item_lock
);
4982 r
->send_in_progress
--;
4983 spin_unlock(&r
->root_item_lock
);
4985 if (sctx
&& !IS_ERR_OR_NULL(sctx
->parent_root
)) {
4986 struct btrfs_root
*r
= sctx
->parent_root
;
4988 spin_lock(&r
->root_item_lock
);
4989 r
->send_in_progress
--;
4990 spin_unlock(&r
->root_item_lock
);
4993 spin_lock(&send_root
->root_item_lock
);
4994 send_root
->send_in_progress
--;
4995 spin_unlock(&send_root
->root_item_lock
);
4998 vfree(clone_sources_tmp
);
5001 if (sctx
->send_filp
)
5002 fput(sctx
->send_filp
);
5004 vfree(sctx
->clone_roots
);
5005 vfree(sctx
->send_buf
);
5006 vfree(sctx
->read_buf
);
5008 name_cache_free(sctx
);