1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2012 Alexander Block. All rights reserved.
6 #include <linux/bsearch.h>
8 #include <linux/file.h>
9 #include <linux/sort.h>
10 #include <linux/mount.h>
11 #include <linux/xattr.h>
12 #include <linux/posix_acl_xattr.h>
13 #include <linux/radix-tree.h>
14 #include <linux/vmalloc.h>
15 #include <linux/string.h>
16 #include <linux/compat.h>
17 #include <linux/crc32c.h>
23 #include "btrfs_inode.h"
24 #include "transaction.h"
25 #include "compression.h"
28 * A fs_path is a helper to dynamically build path names with unknown size.
29 * It reallocates the internal buffer on demand.
30 * It allows fast adding of path elements on the right side (normal path) and
31 * fast adding to the left side (reversed path). A reversed path can also be
32 * unreversed if needed.
41 unsigned short buf_len:15;
42 unsigned short reversed:1;
46 * Average path length does not exceed 200 bytes, we'll have
47 * better packing in the slab and higher chance to satisfy
48 * a allocation later during send.
53 #define FS_PATH_INLINE_SIZE \
54 (sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
57 /* reused for each extent */
59 struct btrfs_root *root;
66 #define SEND_CTX_MAX_NAME_CACHE_SIZE 128
67 #define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
70 struct file *send_filp;
76 u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
77 u64 flags; /* 'flags' member of btrfs_ioctl_send_args is u64 */
79 struct btrfs_root *send_root;
80 struct btrfs_root *parent_root;
81 struct clone_root *clone_roots;
84 /* current state of the compare_tree call */
85 struct btrfs_path *left_path;
86 struct btrfs_path *right_path;
87 struct btrfs_key *cmp_key;
90 * infos of the currently processed inode. In case of deleted inodes,
91 * these are the values from the deleted inode.
96 int cur_inode_new_gen;
97 int cur_inode_deleted;
101 u64 cur_inode_last_extent;
102 u64 cur_inode_next_write_offset;
103 bool ignore_cur_inode;
107 struct list_head new_refs;
108 struct list_head deleted_refs;
110 struct radix_tree_root name_cache;
111 struct list_head name_cache_list;
114 struct file_ra_state ra;
119 * We process inodes by their increasing order, so if before an
120 * incremental send we reverse the parent/child relationship of
121 * directories such that a directory with a lower inode number was
122 * the parent of a directory with a higher inode number, and the one
123 * becoming the new parent got renamed too, we can't rename/move the
124 * directory with lower inode number when we finish processing it - we
125 * must process the directory with higher inode number first, then
126 * rename/move it and then rename/move the directory with lower inode
127 * number. Example follows.
129 * Tree state when the first send was performed:
141 * Tree state when the second (incremental) send is performed:
150 * The sequence of steps that lead to the second state was:
152 * mv /a/b/c/d /a/b/c2/d2
153 * mv /a/b/c /a/b/c2/d2/cc
155 * "c" has lower inode number, but we can't move it (2nd mv operation)
156 * before we move "d", which has higher inode number.
158 * So we just memorize which move/rename operations must be performed
159 * later when their respective parent is processed and moved/renamed.
162 /* Indexed by parent directory inode number. */
163 struct rb_root pending_dir_moves;
166 * Reverse index, indexed by the inode number of a directory that
167 * is waiting for the move/rename of its immediate parent before its
168 * own move/rename can be performed.
170 struct rb_root waiting_dir_moves;
173 * A directory that is going to be rm'ed might have a child directory
174 * which is in the pending directory moves index above. In this case,
175 * the directory can only be removed after the move/rename of its child
176 * is performed. Example:
196 * Sequence of steps that lead to the send snapshot:
197 * rm -f /a/b/c/foo.txt
199 * mv /a/b/c/x /a/b/YY
202 * When the child is processed, its move/rename is delayed until its
203 * parent is processed (as explained above), but all other operations
204 * like update utimes, chown, chgrp, etc, are performed and the paths
205 * that it uses for those operations must use the orphanized name of
206 * its parent (the directory we're going to rm later), so we need to
207 * memorize that name.
209 * Indexed by the inode number of the directory to be deleted.
211 struct rb_root orphan_dirs;
214 struct pending_dir_move {
216 struct list_head list;
220 struct list_head update_refs;
223 struct waiting_dir_move {
227 * There might be some directory that could not be removed because it
228 * was waiting for this directory inode to be moved first. Therefore
229 * after this directory is moved, we can try to rmdir the ino rmdir_ino.
235 struct orphan_dir_info {
239 u64 last_dir_index_offset;
242 struct name_cache_entry {
243 struct list_head list;
245 * radix_tree has only 32bit entries but we need to handle 64bit inums.
246 * We use the lower 32bit of the 64bit inum to store it in the tree. If
247 * more then one inum would fall into the same entry, we use radix_list
248 * to store the additional entries. radix_list is also used to store
249 * entries where two entries have the same inum but different
252 struct list_head radix_list;
258 int need_later_update;
264 #define ADVANCE_ONLY_NEXT -1
266 enum btrfs_compare_tree_result {
267 BTRFS_COMPARE_TREE_NEW,
268 BTRFS_COMPARE_TREE_DELETED,
269 BTRFS_COMPARE_TREE_CHANGED,
270 BTRFS_COMPARE_TREE_SAME,
272 typedef int (*btrfs_changed_cb_t)(struct btrfs_path *left_path,
273 struct btrfs_path *right_path,
274 struct btrfs_key *key,
275 enum btrfs_compare_tree_result result,
279 static void inconsistent_snapshot_error(struct send_ctx *sctx,
280 enum btrfs_compare_tree_result result,
283 const char *result_string;
286 case BTRFS_COMPARE_TREE_NEW:
287 result_string = "new";
289 case BTRFS_COMPARE_TREE_DELETED:
290 result_string = "deleted";
292 case BTRFS_COMPARE_TREE_CHANGED:
293 result_string = "updated";
295 case BTRFS_COMPARE_TREE_SAME:
297 result_string = "unchanged";
301 result_string = "unexpected";
304 btrfs_err(sctx->send_root->fs_info,
305 "Send: inconsistent snapshot, found %s %s for inode %llu without updated inode item, send root is %llu, parent root is %llu",
306 result_string, what, sctx->cmp_key->objectid,
307 sctx->send_root->root_key.objectid,
309 sctx->parent_root->root_key.objectid : 0));
312 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);
314 static struct waiting_dir_move *
315 get_waiting_dir_move(struct send_ctx *sctx, u64 ino);
317 static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino);
319 static int need_send_hole(struct send_ctx *sctx)
321 return (sctx->parent_root && !sctx->cur_inode_new &&
322 !sctx->cur_inode_new_gen && !sctx->cur_inode_deleted &&
323 S_ISREG(sctx->cur_inode_mode));
326 static void fs_path_reset(struct fs_path *p)
329 p->start = p->buf + p->buf_len - 1;
339 static struct fs_path *fs_path_alloc(void)
343 p = kmalloc(sizeof(*p), GFP_KERNEL);
347 p->buf = p->inline_buf;
348 p->buf_len = FS_PATH_INLINE_SIZE;
353 static struct fs_path *fs_path_alloc_reversed(void)
365 static void fs_path_free(struct fs_path *p)
369 if (p->buf != p->inline_buf)
374 static int fs_path_len(struct fs_path *p)
376 return p->end - p->start;
379 static int fs_path_ensure_buf(struct fs_path *p, int len)
387 if (p->buf_len >= len)
390 if (len > PATH_MAX) {
395 path_len = p->end - p->start;
396 old_buf_len = p->buf_len;
399 * First time the inline_buf does not suffice
401 if (p->buf == p->inline_buf) {
402 tmp_buf = kmalloc(len, GFP_KERNEL);
404 memcpy(tmp_buf, p->buf, old_buf_len);
406 tmp_buf = krealloc(p->buf, len, GFP_KERNEL);
412 * The real size of the buffer is bigger, this will let the fast path
413 * happen most of the time
415 p->buf_len = ksize(p->buf);
418 tmp_buf = p->buf + old_buf_len - path_len - 1;
419 p->end = p->buf + p->buf_len - 1;
420 p->start = p->end - path_len;
421 memmove(p->start, tmp_buf, path_len + 1);
424 p->end = p->start + path_len;
429 static int fs_path_prepare_for_add(struct fs_path *p, int name_len,
435 new_len = p->end - p->start + name_len;
436 if (p->start != p->end)
438 ret = fs_path_ensure_buf(p, new_len);
443 if (p->start != p->end)
445 p->start -= name_len;
446 *prepared = p->start;
448 if (p->start != p->end)
459 static int fs_path_add(struct fs_path *p, const char *name, int name_len)
464 ret = fs_path_prepare_for_add(p, name_len, &prepared);
467 memcpy(prepared, name, name_len);
473 static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
478 ret = fs_path_prepare_for_add(p, p2->end - p2->start, &prepared);
481 memcpy(prepared, p2->start, p2->end - p2->start);
487 static int fs_path_add_from_extent_buffer(struct fs_path *p,
488 struct extent_buffer *eb,
489 unsigned long off, int len)
494 ret = fs_path_prepare_for_add(p, len, &prepared);
498 read_extent_buffer(eb, prepared, off, len);
504 static int fs_path_copy(struct fs_path *p, struct fs_path *from)
508 p->reversed = from->reversed;
511 ret = fs_path_add_path(p, from);
517 static void fs_path_unreverse(struct fs_path *p)
526 len = p->end - p->start;
528 p->end = p->start + len;
529 memmove(p->start, tmp, len + 1);
533 static struct btrfs_path *alloc_path_for_send(void)
535 struct btrfs_path *path;
537 path = btrfs_alloc_path();
540 path->search_commit_root = 1;
541 path->skip_locking = 1;
542 path->need_commit_sem = 1;
546 static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
552 ret = kernel_write(filp, buf + pos, len - pos, off);
553 /* TODO handle that correctly */
554 /*if (ret == -ERESTARTSYS) {
568 static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
570 struct btrfs_tlv_header *hdr;
571 int total_len = sizeof(*hdr) + len;
572 int left = sctx->send_max_size - sctx->send_size;
574 if (unlikely(left < total_len))
577 hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
578 hdr->tlv_type = cpu_to_le16(attr);
579 hdr->tlv_len = cpu_to_le16(len);
580 memcpy(hdr + 1, data, len);
581 sctx->send_size += total_len;
586 #define TLV_PUT_DEFINE_INT(bits) \
587 static int tlv_put_u##bits(struct send_ctx *sctx, \
588 u##bits attr, u##bits value) \
590 __le##bits __tmp = cpu_to_le##bits(value); \
591 return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \
594 TLV_PUT_DEFINE_INT(64)
596 static int tlv_put_string(struct send_ctx *sctx, u16 attr,
597 const char *str, int len)
601 return tlv_put(sctx, attr, str, len);
604 static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
607 return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
610 static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
611 struct extent_buffer *eb,
612 struct btrfs_timespec *ts)
614 struct btrfs_timespec bts;
615 read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
616 return tlv_put(sctx, attr, &bts, sizeof(bts));
620 #define TLV_PUT(sctx, attrtype, data, attrlen) \
622 ret = tlv_put(sctx, attrtype, data, attrlen); \
624 goto tlv_put_failure; \
627 #define TLV_PUT_INT(sctx, attrtype, bits, value) \
629 ret = tlv_put_u##bits(sctx, attrtype, value); \
631 goto tlv_put_failure; \
634 #define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
635 #define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
636 #define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
637 #define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
638 #define TLV_PUT_STRING(sctx, attrtype, str, len) \
640 ret = tlv_put_string(sctx, attrtype, str, len); \
642 goto tlv_put_failure; \
644 #define TLV_PUT_PATH(sctx, attrtype, p) \
646 ret = tlv_put_string(sctx, attrtype, p->start, \
647 p->end - p->start); \
649 goto tlv_put_failure; \
651 #define TLV_PUT_UUID(sctx, attrtype, uuid) \
653 ret = tlv_put_uuid(sctx, attrtype, uuid); \
655 goto tlv_put_failure; \
657 #define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
659 ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
661 goto tlv_put_failure; \
664 static int send_header(struct send_ctx *sctx)
666 struct btrfs_stream_header hdr;
668 strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
669 hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
671 return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
676 * For each command/item we want to send to userspace, we call this function.
678 static int begin_cmd(struct send_ctx *sctx, int cmd)
680 struct btrfs_cmd_header *hdr;
682 if (WARN_ON(!sctx->send_buf))
685 BUG_ON(sctx->send_size);
687 sctx->send_size += sizeof(*hdr);
688 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
689 hdr->cmd = cpu_to_le16(cmd);
694 static int send_cmd(struct send_ctx *sctx)
697 struct btrfs_cmd_header *hdr;
700 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
701 hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
704 crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
705 hdr->crc = cpu_to_le32(crc);
707 ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
710 sctx->total_send_size += sctx->send_size;
711 sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
718 * Sends a move instruction to user space
720 static int send_rename(struct send_ctx *sctx,
721 struct fs_path *from, struct fs_path *to)
723 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
726 btrfs_debug(fs_info, "send_rename %s -> %s", from->start, to->start);
728 ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
732 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
733 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
735 ret = send_cmd(sctx);
743 * Sends a link instruction to user space
745 static int send_link(struct send_ctx *sctx,
746 struct fs_path *path, struct fs_path *lnk)
748 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
751 btrfs_debug(fs_info, "send_link %s -> %s", path->start, lnk->start);
753 ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
757 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
758 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
760 ret = send_cmd(sctx);
768 * Sends an unlink instruction to user space
770 static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
772 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
775 btrfs_debug(fs_info, "send_unlink %s", path->start);
777 ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
781 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
783 ret = send_cmd(sctx);
791 * Sends a rmdir instruction to user space
793 static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
795 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
798 btrfs_debug(fs_info, "send_rmdir %s", path->start);
800 ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
804 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
806 ret = send_cmd(sctx);
814 * Helper function to retrieve some fields from an inode item.
816 static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
817 u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid,
821 struct btrfs_inode_item *ii;
822 struct btrfs_key key;
825 key.type = BTRFS_INODE_ITEM_KEY;
827 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
834 ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
835 struct btrfs_inode_item);
837 *size = btrfs_inode_size(path->nodes[0], ii);
839 *gen = btrfs_inode_generation(path->nodes[0], ii);
841 *mode = btrfs_inode_mode(path->nodes[0], ii);
843 *uid = btrfs_inode_uid(path->nodes[0], ii);
845 *gid = btrfs_inode_gid(path->nodes[0], ii);
847 *rdev = btrfs_inode_rdev(path->nodes[0], ii);
852 static int get_inode_info(struct btrfs_root *root,
853 u64 ino, u64 *size, u64 *gen,
854 u64 *mode, u64 *uid, u64 *gid,
857 struct btrfs_path *path;
860 path = alloc_path_for_send();
863 ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid,
865 btrfs_free_path(path);
869 typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
874 * Helper function to iterate the entries in ONE btrfs_inode_ref or
875 * btrfs_inode_extref.
876 * The iterate callback may return a non zero value to stop iteration. This can
877 * be a negative value for error codes or 1 to simply stop it.
879 * path must point to the INODE_REF or INODE_EXTREF when called.
881 static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
882 struct btrfs_key *found_key, int resolve,
883 iterate_inode_ref_t iterate, void *ctx)
885 struct extent_buffer *eb = path->nodes[0];
886 struct btrfs_item *item;
887 struct btrfs_inode_ref *iref;
888 struct btrfs_inode_extref *extref;
889 struct btrfs_path *tmp_path;
893 int slot = path->slots[0];
900 unsigned long name_off;
901 unsigned long elem_size;
904 p = fs_path_alloc_reversed();
908 tmp_path = alloc_path_for_send();
915 if (found_key->type == BTRFS_INODE_REF_KEY) {
916 ptr = (unsigned long)btrfs_item_ptr(eb, slot,
917 struct btrfs_inode_ref);
918 item = btrfs_item_nr(slot);
919 total = btrfs_item_size(eb, item);
920 elem_size = sizeof(*iref);
922 ptr = btrfs_item_ptr_offset(eb, slot);
923 total = btrfs_item_size_nr(eb, slot);
924 elem_size = sizeof(*extref);
927 while (cur < total) {
930 if (found_key->type == BTRFS_INODE_REF_KEY) {
931 iref = (struct btrfs_inode_ref *)(ptr + cur);
932 name_len = btrfs_inode_ref_name_len(eb, iref);
933 name_off = (unsigned long)(iref + 1);
934 index = btrfs_inode_ref_index(eb, iref);
935 dir = found_key->offset;
937 extref = (struct btrfs_inode_extref *)(ptr + cur);
938 name_len = btrfs_inode_extref_name_len(eb, extref);
939 name_off = (unsigned long)&extref->name;
940 index = btrfs_inode_extref_index(eb, extref);
941 dir = btrfs_inode_extref_parent(eb, extref);
945 start = btrfs_ref_to_path(root, tmp_path, name_len,
949 ret = PTR_ERR(start);
952 if (start < p->buf) {
953 /* overflow , try again with larger buffer */
954 ret = fs_path_ensure_buf(p,
955 p->buf_len + p->buf - start);
958 start = btrfs_ref_to_path(root, tmp_path,
963 ret = PTR_ERR(start);
966 BUG_ON(start < p->buf);
970 ret = fs_path_add_from_extent_buffer(p, eb, name_off,
976 cur += elem_size + name_len;
977 ret = iterate(num, dir, index, p, ctx);
984 btrfs_free_path(tmp_path);
989 typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
990 const char *name, int name_len,
991 const char *data, int data_len,
995 * Helper function to iterate the entries in ONE btrfs_dir_item.
996 * The iterate callback may return a non zero value to stop iteration. This can
997 * be a negative value for error codes or 1 to simply stop it.
999 * path must point to the dir item when called.
1001 static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
1002 iterate_dir_item_t iterate, void *ctx)
1005 struct extent_buffer *eb;
1006 struct btrfs_item *item;
1007 struct btrfs_dir_item *di;
1008 struct btrfs_key di_key;
1021 * Start with a small buffer (1 page). If later we end up needing more
1022 * space, which can happen for xattrs on a fs with a leaf size greater
1023 * then the page size, attempt to increase the buffer. Typically xattr
1027 buf = kmalloc(buf_len, GFP_KERNEL);
1033 eb = path->nodes[0];
1034 slot = path->slots[0];
1035 item = btrfs_item_nr(slot);
1036 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
1039 total = btrfs_item_size(eb, item);
1042 while (cur < total) {
1043 name_len = btrfs_dir_name_len(eb, di);
1044 data_len = btrfs_dir_data_len(eb, di);
1045 type = btrfs_dir_type(eb, di);
1046 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
1048 if (type == BTRFS_FT_XATTR) {
1049 if (name_len > XATTR_NAME_MAX) {
1050 ret = -ENAMETOOLONG;
1053 if (name_len + data_len >
1054 BTRFS_MAX_XATTR_SIZE(root->fs_info)) {
1062 if (name_len + data_len > PATH_MAX) {
1063 ret = -ENAMETOOLONG;
1068 if (name_len + data_len > buf_len) {
1069 buf_len = name_len + data_len;
1070 if (is_vmalloc_addr(buf)) {
1074 char *tmp = krealloc(buf, buf_len,
1075 GFP_KERNEL | __GFP_NOWARN);
1082 buf = kvmalloc(buf_len, GFP_KERNEL);
1090 read_extent_buffer(eb, buf, (unsigned long)(di + 1),
1091 name_len + data_len);
1093 len = sizeof(*di) + name_len + data_len;
1094 di = (struct btrfs_dir_item *)((char *)di + len);
1097 ret = iterate(num, &di_key, buf, name_len, buf + name_len,
1098 data_len, type, ctx);
1114 static int __copy_first_ref(int num, u64 dir, int index,
1115 struct fs_path *p, void *ctx)
1118 struct fs_path *pt = ctx;
1120 ret = fs_path_copy(pt, p);
1124 /* we want the first only */
1129 * Retrieve the first path of an inode. If an inode has more then one
1130 * ref/hardlink, this is ignored.
1132 static int get_inode_path(struct btrfs_root *root,
1133 u64 ino, struct fs_path *path)
1136 struct btrfs_key key, found_key;
1137 struct btrfs_path *p;
1139 p = alloc_path_for_send();
1143 fs_path_reset(path);
1146 key.type = BTRFS_INODE_REF_KEY;
1149 ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
1156 btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
1157 if (found_key.objectid != ino ||
1158 (found_key.type != BTRFS_INODE_REF_KEY &&
1159 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1164 ret = iterate_inode_ref(root, p, &found_key, 1,
1165 __copy_first_ref, path);
1175 struct backref_ctx {
1176 struct send_ctx *sctx;
1178 /* number of total found references */
1182 * used for clones found in send_root. clones found behind cur_objectid
1183 * and cur_offset are not considered as allowed clones.
1188 /* may be truncated in case it's the last extent in a file */
1191 /* data offset in the file extent item */
1194 /* Just to check for bugs in backref resolving */
1198 static int __clone_root_cmp_bsearch(const void *key, const void *elt)
1200 u64 root = (u64)(uintptr_t)key;
1201 struct clone_root *cr = (struct clone_root *)elt;
1203 if (root < cr->root->root_key.objectid)
1205 if (root > cr->root->root_key.objectid)
1210 static int __clone_root_cmp_sort(const void *e1, const void *e2)
1212 struct clone_root *cr1 = (struct clone_root *)e1;
1213 struct clone_root *cr2 = (struct clone_root *)e2;
1215 if (cr1->root->root_key.objectid < cr2->root->root_key.objectid)
1217 if (cr1->root->root_key.objectid > cr2->root->root_key.objectid)
1223 * Called for every backref that is found for the current extent.
1224 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1226 static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
1228 struct backref_ctx *bctx = ctx_;
1229 struct clone_root *found;
1231 /* First check if the root is in the list of accepted clone sources */
1232 found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1233 bctx->sctx->clone_roots_cnt,
1234 sizeof(struct clone_root),
1235 __clone_root_cmp_bsearch);
1239 if (found->root == bctx->sctx->send_root &&
1240 ino == bctx->cur_objectid &&
1241 offset == bctx->cur_offset) {
1242 bctx->found_itself = 1;
1246 * Make sure we don't consider clones from send_root that are
1247 * behind the current inode/offset.
1249 if (found->root == bctx->sctx->send_root) {
1251 * TODO for the moment we don't accept clones from the inode
1252 * that is currently send. We may change this when
1253 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1256 if (ino >= bctx->cur_objectid)
1261 found->found_refs++;
1262 if (ino < found->ino) {
1264 found->offset = offset;
1265 } else if (found->ino == ino) {
1267 * same extent found more then once in the same file.
1269 if (found->offset > offset + bctx->extent_len)
1270 found->offset = offset;
1277 * Given an inode, offset and extent item, it finds a good clone for a clone
1278 * instruction. Returns -ENOENT when none could be found. The function makes
1279 * sure that the returned clone is usable at the point where sending is at the
1280 * moment. This means, that no clones are accepted which lie behind the current
1283 * path must point to the extent item when called.
1285 static int find_extent_clone(struct send_ctx *sctx,
1286 struct btrfs_path *path,
1287 u64 ino, u64 data_offset,
1289 struct clone_root **found)
1291 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
1297 u64 extent_item_pos;
1299 struct btrfs_file_extent_item *fi;
1300 struct extent_buffer *eb = path->nodes[0];
1301 struct backref_ctx *backref_ctx = NULL;
1302 struct clone_root *cur_clone_root;
1303 struct btrfs_key found_key;
1304 struct btrfs_path *tmp_path;
1308 tmp_path = alloc_path_for_send();
1312 /* We only use this path under the commit sem */
1313 tmp_path->need_commit_sem = 0;
1315 backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_KERNEL);
1321 if (data_offset >= ino_size) {
1323 * There may be extents that lie behind the file's size.
1324 * I at least had this in combination with snapshotting while
1325 * writing large files.
1331 fi = btrfs_item_ptr(eb, path->slots[0],
1332 struct btrfs_file_extent_item);
1333 extent_type = btrfs_file_extent_type(eb, fi);
1334 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1338 compressed = btrfs_file_extent_compression(eb, fi);
1340 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1341 disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
1342 if (disk_byte == 0) {
1346 logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1348 down_read(&fs_info->commit_root_sem);
1349 ret = extent_from_logical(fs_info, disk_byte, tmp_path,
1350 &found_key, &flags);
1351 up_read(&fs_info->commit_root_sem);
1352 btrfs_release_path(tmp_path);
1356 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1362 * Setup the clone roots.
1364 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1365 cur_clone_root = sctx->clone_roots + i;
1366 cur_clone_root->ino = (u64)-1;
1367 cur_clone_root->offset = 0;
1368 cur_clone_root->found_refs = 0;
1371 backref_ctx->sctx = sctx;
1372 backref_ctx->found = 0;
1373 backref_ctx->cur_objectid = ino;
1374 backref_ctx->cur_offset = data_offset;
1375 backref_ctx->found_itself = 0;
1376 backref_ctx->extent_len = num_bytes;
1378 * For non-compressed extents iterate_extent_inodes() gives us extent
1379 * offsets that already take into account the data offset, but not for
1380 * compressed extents, since the offset is logical and not relative to
1381 * the physical extent locations. We must take this into account to
1382 * avoid sending clone offsets that go beyond the source file's size,
1383 * which would result in the clone ioctl failing with -EINVAL on the
1386 if (compressed == BTRFS_COMPRESS_NONE)
1387 backref_ctx->data_offset = 0;
1389 backref_ctx->data_offset = btrfs_file_extent_offset(eb, fi);
1392 * The last extent of a file may be too large due to page alignment.
1393 * We need to adjust extent_len in this case so that the checks in
1394 * __iterate_backrefs work.
1396 if (data_offset + num_bytes >= ino_size)
1397 backref_ctx->extent_len = ino_size - data_offset;
1400 * Now collect all backrefs.
1402 if (compressed == BTRFS_COMPRESS_NONE)
1403 extent_item_pos = logical - found_key.objectid;
1405 extent_item_pos = 0;
1406 ret = iterate_extent_inodes(fs_info, found_key.objectid,
1407 extent_item_pos, 1, __iterate_backrefs,
1408 backref_ctx, false);
1413 if (!backref_ctx->found_itself) {
1414 /* found a bug in backref code? */
1417 "did not find backref in send_root. inode=%llu, offset=%llu, disk_byte=%llu found extent=%llu",
1418 ino, data_offset, disk_byte, found_key.objectid);
1422 btrfs_debug(fs_info,
1423 "find_extent_clone: data_offset=%llu, ino=%llu, num_bytes=%llu, logical=%llu",
1424 data_offset, ino, num_bytes, logical);
1426 if (!backref_ctx->found)
1427 btrfs_debug(fs_info, "no clones found");
1429 cur_clone_root = NULL;
1430 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1431 if (sctx->clone_roots[i].found_refs) {
1432 if (!cur_clone_root)
1433 cur_clone_root = sctx->clone_roots + i;
1434 else if (sctx->clone_roots[i].root == sctx->send_root)
1435 /* prefer clones from send_root over others */
1436 cur_clone_root = sctx->clone_roots + i;
1441 if (cur_clone_root) {
1442 *found = cur_clone_root;
1449 btrfs_free_path(tmp_path);
1454 static int read_symlink(struct btrfs_root *root,
1456 struct fs_path *dest)
1459 struct btrfs_path *path;
1460 struct btrfs_key key;
1461 struct btrfs_file_extent_item *ei;
1467 path = alloc_path_for_send();
1472 key.type = BTRFS_EXTENT_DATA_KEY;
1474 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1479 * An empty symlink inode. Can happen in rare error paths when
1480 * creating a symlink (transaction committed before the inode
1481 * eviction handler removed the symlink inode items and a crash
1482 * happened in between or the subvol was snapshoted in between).
1483 * Print an informative message to dmesg/syslog so that the user
1484 * can delete the symlink.
1486 btrfs_err(root->fs_info,
1487 "Found empty symlink inode %llu at root %llu",
1488 ino, root->root_key.objectid);
1493 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
1494 struct btrfs_file_extent_item);
1495 type = btrfs_file_extent_type(path->nodes[0], ei);
1496 compression = btrfs_file_extent_compression(path->nodes[0], ei);
1497 BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
1498 BUG_ON(compression);
1500 off = btrfs_file_extent_inline_start(ei);
1501 len = btrfs_file_extent_ram_bytes(path->nodes[0], ei);
1503 ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
1506 btrfs_free_path(path);
1511 * Helper function to generate a file name that is unique in the root of
1512 * send_root and parent_root. This is used to generate names for orphan inodes.
1514 static int gen_unique_name(struct send_ctx *sctx,
1516 struct fs_path *dest)
1519 struct btrfs_path *path;
1520 struct btrfs_dir_item *di;
1525 path = alloc_path_for_send();
1530 len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
1532 ASSERT(len < sizeof(tmp));
1534 di = btrfs_lookup_dir_item(NULL, sctx->send_root,
1535 path, BTRFS_FIRST_FREE_OBJECTID,
1536 tmp, strlen(tmp), 0);
1537 btrfs_release_path(path);
1543 /* not unique, try again */
1548 if (!sctx->parent_root) {
1554 di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
1555 path, BTRFS_FIRST_FREE_OBJECTID,
1556 tmp, strlen(tmp), 0);
1557 btrfs_release_path(path);
1563 /* not unique, try again */
1571 ret = fs_path_add(dest, tmp, strlen(tmp));
1574 btrfs_free_path(path);
1579 inode_state_no_change,
1580 inode_state_will_create,
1581 inode_state_did_create,
1582 inode_state_will_delete,
1583 inode_state_did_delete,
1586 static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
1594 ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1596 if (ret < 0 && ret != -ENOENT)
1600 if (!sctx->parent_root) {
1601 right_ret = -ENOENT;
1603 ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1604 NULL, NULL, NULL, NULL);
1605 if (ret < 0 && ret != -ENOENT)
1610 if (!left_ret && !right_ret) {
1611 if (left_gen == gen && right_gen == gen) {
1612 ret = inode_state_no_change;
1613 } else if (left_gen == gen) {
1614 if (ino < sctx->send_progress)
1615 ret = inode_state_did_create;
1617 ret = inode_state_will_create;
1618 } else if (right_gen == gen) {
1619 if (ino < sctx->send_progress)
1620 ret = inode_state_did_delete;
1622 ret = inode_state_will_delete;
1626 } else if (!left_ret) {
1627 if (left_gen == gen) {
1628 if (ino < sctx->send_progress)
1629 ret = inode_state_did_create;
1631 ret = inode_state_will_create;
1635 } else if (!right_ret) {
1636 if (right_gen == gen) {
1637 if (ino < sctx->send_progress)
1638 ret = inode_state_did_delete;
1640 ret = inode_state_will_delete;
1652 static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
1656 if (ino == BTRFS_FIRST_FREE_OBJECTID)
1659 ret = get_cur_inode_state(sctx, ino, gen);
1663 if (ret == inode_state_no_change ||
1664 ret == inode_state_did_create ||
1665 ret == inode_state_will_delete)
1675 * Helper function to lookup a dir item in a dir.
1677 static int lookup_dir_item_inode(struct btrfs_root *root,
1678 u64 dir, const char *name, int name_len,
1683 struct btrfs_dir_item *di;
1684 struct btrfs_key key;
1685 struct btrfs_path *path;
1687 path = alloc_path_for_send();
1691 di = btrfs_lookup_dir_item(NULL, root, path,
1692 dir, name, name_len, 0);
1693 if (IS_ERR_OR_NULL(di)) {
1694 ret = di ? PTR_ERR(di) : -ENOENT;
1697 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1698 if (key.type == BTRFS_ROOT_ITEM_KEY) {
1702 *found_inode = key.objectid;
1703 *found_type = btrfs_dir_type(path->nodes[0], di);
1706 btrfs_free_path(path);
1711 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
1712 * generation of the parent dir and the name of the dir entry.
1714 static int get_first_ref(struct btrfs_root *root, u64 ino,
1715 u64 *dir, u64 *dir_gen, struct fs_path *name)
1718 struct btrfs_key key;
1719 struct btrfs_key found_key;
1720 struct btrfs_path *path;
1724 path = alloc_path_for_send();
1729 key.type = BTRFS_INODE_REF_KEY;
1732 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
1736 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1738 if (ret || found_key.objectid != ino ||
1739 (found_key.type != BTRFS_INODE_REF_KEY &&
1740 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1745 if (found_key.type == BTRFS_INODE_REF_KEY) {
1746 struct btrfs_inode_ref *iref;
1747 iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1748 struct btrfs_inode_ref);
1749 len = btrfs_inode_ref_name_len(path->nodes[0], iref);
1750 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1751 (unsigned long)(iref + 1),
1753 parent_dir = found_key.offset;
1755 struct btrfs_inode_extref *extref;
1756 extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1757 struct btrfs_inode_extref);
1758 len = btrfs_inode_extref_name_len(path->nodes[0], extref);
1759 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1760 (unsigned long)&extref->name, len);
1761 parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
1765 btrfs_release_path(path);
1768 ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL,
1777 btrfs_free_path(path);
1781 static int is_first_ref(struct btrfs_root *root,
1783 const char *name, int name_len)
1786 struct fs_path *tmp_name;
1789 tmp_name = fs_path_alloc();
1793 ret = get_first_ref(root, ino, &tmp_dir, NULL, tmp_name);
1797 if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1802 ret = !memcmp(tmp_name->start, name, name_len);
1805 fs_path_free(tmp_name);
1810 * Used by process_recorded_refs to determine if a new ref would overwrite an
1811 * already existing ref. In case it detects an overwrite, it returns the
1812 * inode/gen in who_ino/who_gen.
1813 * When an overwrite is detected, process_recorded_refs does proper orphanizing
1814 * to make sure later references to the overwritten inode are possible.
1815 * Orphanizing is however only required for the first ref of an inode.
1816 * process_recorded_refs does an additional is_first_ref check to see if
1817 * orphanizing is really required.
1819 static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
1820 const char *name, int name_len,
1821 u64 *who_ino, u64 *who_gen, u64 *who_mode)
1825 u64 other_inode = 0;
1828 if (!sctx->parent_root)
1831 ret = is_inode_existent(sctx, dir, dir_gen);
1836 * If we have a parent root we need to verify that the parent dir was
1837 * not deleted and then re-created, if it was then we have no overwrite
1838 * and we can just unlink this entry.
1840 if (sctx->parent_root && dir != BTRFS_FIRST_FREE_OBJECTID) {
1841 ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
1843 if (ret < 0 && ret != -ENOENT)
1853 ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
1854 &other_inode, &other_type);
1855 if (ret < 0 && ret != -ENOENT)
1863 * Check if the overwritten ref was already processed. If yes, the ref
1864 * was already unlinked/moved, so we can safely assume that we will not
1865 * overwrite anything at this point in time.
1867 if (other_inode > sctx->send_progress ||
1868 is_waiting_for_move(sctx, other_inode)) {
1869 ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1870 who_gen, who_mode, NULL, NULL, NULL);
1875 *who_ino = other_inode;
1885 * Checks if the ref was overwritten by an already processed inode. This is
1886 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
1887 * thus the orphan name needs be used.
1888 * process_recorded_refs also uses it to avoid unlinking of refs that were
1891 static int did_overwrite_ref(struct send_ctx *sctx,
1892 u64 dir, u64 dir_gen,
1893 u64 ino, u64 ino_gen,
1894 const char *name, int name_len)
1901 if (!sctx->parent_root)
1904 ret = is_inode_existent(sctx, dir, dir_gen);
1908 if (dir != BTRFS_FIRST_FREE_OBJECTID) {
1909 ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL,
1911 if (ret < 0 && ret != -ENOENT)
1921 /* check if the ref was overwritten by another ref */
1922 ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
1923 &ow_inode, &other_type);
1924 if (ret < 0 && ret != -ENOENT)
1927 /* was never and will never be overwritten */
1932 ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1937 if (ow_inode == ino && gen == ino_gen) {
1943 * We know that it is or will be overwritten. Check this now.
1944 * The current inode being processed might have been the one that caused
1945 * inode 'ino' to be orphanized, therefore check if ow_inode matches
1946 * the current inode being processed.
1948 if ((ow_inode < sctx->send_progress) ||
1949 (ino != sctx->cur_ino && ow_inode == sctx->cur_ino &&
1950 gen == sctx->cur_inode_gen))
1960 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
1961 * that got overwritten. This is used by process_recorded_refs to determine
1962 * if it has to use the path as returned by get_cur_path or the orphan name.
1964 static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
1967 struct fs_path *name = NULL;
1971 if (!sctx->parent_root)
1974 name = fs_path_alloc();
1978 ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
1982 ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
1983 name->start, fs_path_len(name));
1991 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
1992 * so we need to do some special handling in case we have clashes. This function
1993 * takes care of this with the help of name_cache_entry::radix_list.
1994 * In case of error, nce is kfreed.
1996 static int name_cache_insert(struct send_ctx *sctx,
1997 struct name_cache_entry *nce)
2000 struct list_head *nce_head;
2002 nce_head = radix_tree_lookup(&sctx->name_cache,
2003 (unsigned long)nce->ino);
2005 nce_head = kmalloc(sizeof(*nce_head), GFP_KERNEL);
2010 INIT_LIST_HEAD(nce_head);
2012 ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
2019 list_add_tail(&nce->radix_list, nce_head);
2020 list_add_tail(&nce->list, &sctx->name_cache_list);
2021 sctx->name_cache_size++;
2026 static void name_cache_delete(struct send_ctx *sctx,
2027 struct name_cache_entry *nce)
2029 struct list_head *nce_head;
2031 nce_head = radix_tree_lookup(&sctx->name_cache,
2032 (unsigned long)nce->ino);
2034 btrfs_err(sctx->send_root->fs_info,
2035 "name_cache_delete lookup failed ino %llu cache size %d, leaking memory",
2036 nce->ino, sctx->name_cache_size);
2039 list_del(&nce->radix_list);
2040 list_del(&nce->list);
2041 sctx->name_cache_size--;
2044 * We may not get to the final release of nce_head if the lookup fails
2046 if (nce_head && list_empty(nce_head)) {
2047 radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
2052 static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
2055 struct list_head *nce_head;
2056 struct name_cache_entry *cur;
2058 nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
2062 list_for_each_entry(cur, nce_head, radix_list) {
2063 if (cur->ino == ino && cur->gen == gen)
2070 * Removes the entry from the list and adds it back to the end. This marks the
2071 * entry as recently used so that name_cache_clean_unused does not remove it.
2073 static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
2075 list_del(&nce->list);
2076 list_add_tail(&nce->list, &sctx->name_cache_list);
2080 * Remove some entries from the beginning of name_cache_list.
2082 static void name_cache_clean_unused(struct send_ctx *sctx)
2084 struct name_cache_entry *nce;
2086 if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
2089 while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
2090 nce = list_entry(sctx->name_cache_list.next,
2091 struct name_cache_entry, list);
2092 name_cache_delete(sctx, nce);
2097 static void name_cache_free(struct send_ctx *sctx)
2099 struct name_cache_entry *nce;
2101 while (!list_empty(&sctx->name_cache_list)) {
2102 nce = list_entry(sctx->name_cache_list.next,
2103 struct name_cache_entry, list);
2104 name_cache_delete(sctx, nce);
2110 * Used by get_cur_path for each ref up to the root.
2111 * Returns 0 if it succeeded.
2112 * Returns 1 if the inode is not existent or got overwritten. In that case, the
2113 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
2114 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
2115 * Returns <0 in case of error.
2117 static int __get_cur_name_and_parent(struct send_ctx *sctx,
2121 struct fs_path *dest)
2125 struct name_cache_entry *nce = NULL;
2128 * First check if we already did a call to this function with the same
2129 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
2130 * return the cached result.
2132 nce = name_cache_search(sctx, ino, gen);
2134 if (ino < sctx->send_progress && nce->need_later_update) {
2135 name_cache_delete(sctx, nce);
2139 name_cache_used(sctx, nce);
2140 *parent_ino = nce->parent_ino;
2141 *parent_gen = nce->parent_gen;
2142 ret = fs_path_add(dest, nce->name, nce->name_len);
2151 * If the inode is not existent yet, add the orphan name and return 1.
2152 * This should only happen for the parent dir that we determine in
2155 ret = is_inode_existent(sctx, ino, gen);
2160 ret = gen_unique_name(sctx, ino, gen, dest);
2168 * Depending on whether the inode was already processed or not, use
2169 * send_root or parent_root for ref lookup.
2171 if (ino < sctx->send_progress)
2172 ret = get_first_ref(sctx->send_root, ino,
2173 parent_ino, parent_gen, dest);
2175 ret = get_first_ref(sctx->parent_root, ino,
2176 parent_ino, parent_gen, dest);
2181 * Check if the ref was overwritten by an inode's ref that was processed
2182 * earlier. If yes, treat as orphan and return 1.
2184 ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
2185 dest->start, dest->end - dest->start);
2189 fs_path_reset(dest);
2190 ret = gen_unique_name(sctx, ino, gen, dest);
2198 * Store the result of the lookup in the name cache.
2200 nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_KERNEL);
2208 nce->parent_ino = *parent_ino;
2209 nce->parent_gen = *parent_gen;
2210 nce->name_len = fs_path_len(dest);
2212 strcpy(nce->name, dest->start);
2214 if (ino < sctx->send_progress)
2215 nce->need_later_update = 0;
2217 nce->need_later_update = 1;
2219 nce_ret = name_cache_insert(sctx, nce);
2222 name_cache_clean_unused(sctx);
2229 * Magic happens here. This function returns the first ref to an inode as it
2230 * would look like while receiving the stream at this point in time.
2231 * We walk the path up to the root. For every inode in between, we check if it
2232 * was already processed/sent. If yes, we continue with the parent as found
2233 * in send_root. If not, we continue with the parent as found in parent_root.
2234 * If we encounter an inode that was deleted at this point in time, we use the
2235 * inodes "orphan" name instead of the real name and stop. Same with new inodes
2236 * that were not created yet and overwritten inodes/refs.
2238 * When do we have orphan inodes:
2239 * 1. When an inode is freshly created and thus no valid refs are available yet
2240 * 2. When a directory lost all it's refs (deleted) but still has dir items
2241 * inside which were not processed yet (pending for move/delete). If anyone
2242 * tried to get the path to the dir items, it would get a path inside that
2244 * 3. When an inode is moved around or gets new links, it may overwrite the ref
2245 * of an unprocessed inode. If in that case the first ref would be
2246 * overwritten, the overwritten inode gets "orphanized". Later when we
2247 * process this overwritten inode, it is restored at a new place by moving
2250 * sctx->send_progress tells this function at which point in time receiving
2253 static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
2254 struct fs_path *dest)
2257 struct fs_path *name = NULL;
2258 u64 parent_inode = 0;
2262 name = fs_path_alloc();
2269 fs_path_reset(dest);
2271 while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
2272 struct waiting_dir_move *wdm;
2274 fs_path_reset(name);
2276 if (is_waiting_for_rm(sctx, ino)) {
2277 ret = gen_unique_name(sctx, ino, gen, name);
2280 ret = fs_path_add_path(dest, name);
2284 wdm = get_waiting_dir_move(sctx, ino);
2285 if (wdm && wdm->orphanized) {
2286 ret = gen_unique_name(sctx, ino, gen, name);
2289 ret = get_first_ref(sctx->parent_root, ino,
2290 &parent_inode, &parent_gen, name);
2292 ret = __get_cur_name_and_parent(sctx, ino, gen,
2302 ret = fs_path_add_path(dest, name);
2313 fs_path_unreverse(dest);
2318 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2320 static int send_subvol_begin(struct send_ctx *sctx)
2323 struct btrfs_root *send_root = sctx->send_root;
2324 struct btrfs_root *parent_root = sctx->parent_root;
2325 struct btrfs_path *path;
2326 struct btrfs_key key;
2327 struct btrfs_root_ref *ref;
2328 struct extent_buffer *leaf;
2332 path = btrfs_alloc_path();
2336 name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_KERNEL);
2338 btrfs_free_path(path);
2342 key.objectid = send_root->root_key.objectid;
2343 key.type = BTRFS_ROOT_BACKREF_KEY;
2346 ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
2355 leaf = path->nodes[0];
2356 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2357 if (key.type != BTRFS_ROOT_BACKREF_KEY ||
2358 key.objectid != send_root->root_key.objectid) {
2362 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
2363 namelen = btrfs_root_ref_name_len(leaf, ref);
2364 read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
2365 btrfs_release_path(path);
2368 ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
2372 ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
2377 TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
2379 if (!btrfs_is_empty_uuid(sctx->send_root->root_item.received_uuid))
2380 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2381 sctx->send_root->root_item.received_uuid);
2383 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2384 sctx->send_root->root_item.uuid);
2386 TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2387 le64_to_cpu(sctx->send_root->root_item.ctransid));
2389 if (!btrfs_is_empty_uuid(parent_root->root_item.received_uuid))
2390 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2391 parent_root->root_item.received_uuid);
2393 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2394 parent_root->root_item.uuid);
2395 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2396 le64_to_cpu(sctx->parent_root->root_item.ctransid));
2399 ret = send_cmd(sctx);
2403 btrfs_free_path(path);
2408 static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
2410 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2414 btrfs_debug(fs_info, "send_truncate %llu size=%llu", ino, size);
2416 p = fs_path_alloc();
2420 ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
2424 ret = get_cur_path(sctx, ino, gen, p);
2427 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2428 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
2430 ret = send_cmd(sctx);
2438 static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
2440 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2444 btrfs_debug(fs_info, "send_chmod %llu mode=%llu", ino, mode);
2446 p = fs_path_alloc();
2450 ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
2454 ret = get_cur_path(sctx, ino, gen, p);
2457 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2458 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
2460 ret = send_cmd(sctx);
2468 static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
2470 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2474 btrfs_debug(fs_info, "send_chown %llu uid=%llu, gid=%llu",
2477 p = fs_path_alloc();
2481 ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
2485 ret = get_cur_path(sctx, ino, gen, p);
2488 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2489 TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
2490 TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
2492 ret = send_cmd(sctx);
2500 static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
2502 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2504 struct fs_path *p = NULL;
2505 struct btrfs_inode_item *ii;
2506 struct btrfs_path *path = NULL;
2507 struct extent_buffer *eb;
2508 struct btrfs_key key;
2511 btrfs_debug(fs_info, "send_utimes %llu", ino);
2513 p = fs_path_alloc();
2517 path = alloc_path_for_send();
2524 key.type = BTRFS_INODE_ITEM_KEY;
2526 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2532 eb = path->nodes[0];
2533 slot = path->slots[0];
2534 ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2536 ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
2540 ret = get_cur_path(sctx, ino, gen, p);
2543 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2544 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb, &ii->atime);
2545 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb, &ii->mtime);
2546 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb, &ii->ctime);
2547 /* TODO Add otime support when the otime patches get into upstream */
2549 ret = send_cmd(sctx);
2554 btrfs_free_path(path);
2559 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2560 * a valid path yet because we did not process the refs yet. So, the inode
2561 * is created as orphan.
2563 static int send_create_inode(struct send_ctx *sctx, u64 ino)
2565 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
2573 btrfs_debug(fs_info, "send_create_inode %llu", ino);
2575 p = fs_path_alloc();
2579 if (ino != sctx->cur_ino) {
2580 ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode,
2585 gen = sctx->cur_inode_gen;
2586 mode = sctx->cur_inode_mode;
2587 rdev = sctx->cur_inode_rdev;
2590 if (S_ISREG(mode)) {
2591 cmd = BTRFS_SEND_C_MKFILE;
2592 } else if (S_ISDIR(mode)) {
2593 cmd = BTRFS_SEND_C_MKDIR;
2594 } else if (S_ISLNK(mode)) {
2595 cmd = BTRFS_SEND_C_SYMLINK;
2596 } else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2597 cmd = BTRFS_SEND_C_MKNOD;
2598 } else if (S_ISFIFO(mode)) {
2599 cmd = BTRFS_SEND_C_MKFIFO;
2600 } else if (S_ISSOCK(mode)) {
2601 cmd = BTRFS_SEND_C_MKSOCK;
2603 btrfs_warn(sctx->send_root->fs_info, "unexpected inode type %o",
2604 (int)(mode & S_IFMT));
2609 ret = begin_cmd(sctx, cmd);
2613 ret = gen_unique_name(sctx, ino, gen, p);
2617 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2618 TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2620 if (S_ISLNK(mode)) {
2622 ret = read_symlink(sctx->send_root, ino, p);
2625 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
2626 } else if (S_ISCHR(mode) || S_ISBLK(mode) ||
2627 S_ISFIFO(mode) || S_ISSOCK(mode)) {
2628 TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
2629 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2632 ret = send_cmd(sctx);
2644 * We need some special handling for inodes that get processed before the parent
2645 * directory got created. See process_recorded_refs for details.
2646 * This function does the check if we already created the dir out of order.
2648 static int did_create_dir(struct send_ctx *sctx, u64 dir)
2651 struct btrfs_path *path = NULL;
2652 struct btrfs_key key;
2653 struct btrfs_key found_key;
2654 struct btrfs_key di_key;
2655 struct extent_buffer *eb;
2656 struct btrfs_dir_item *di;
2659 path = alloc_path_for_send();
2666 key.type = BTRFS_DIR_INDEX_KEY;
2668 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2673 eb = path->nodes[0];
2674 slot = path->slots[0];
2675 if (slot >= btrfs_header_nritems(eb)) {
2676 ret = btrfs_next_leaf(sctx->send_root, path);
2679 } else if (ret > 0) {
2686 btrfs_item_key_to_cpu(eb, &found_key, slot);
2687 if (found_key.objectid != key.objectid ||
2688 found_key.type != key.type) {
2693 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2694 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2696 if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
2697 di_key.objectid < sctx->send_progress) {
2706 btrfs_free_path(path);
2711 * Only creates the inode if it is:
2712 * 1. Not a directory
2713 * 2. Or a directory which was not created already due to out of order
2714 * directories. See did_create_dir and process_recorded_refs for details.
2716 static int send_create_inode_if_needed(struct send_ctx *sctx)
2720 if (S_ISDIR(sctx->cur_inode_mode)) {
2721 ret = did_create_dir(sctx, sctx->cur_ino);
2730 ret = send_create_inode(sctx, sctx->cur_ino);
2738 struct recorded_ref {
2739 struct list_head list;
2741 struct fs_path *full_path;
2747 static void set_ref_path(struct recorded_ref *ref, struct fs_path *path)
2749 ref->full_path = path;
2750 ref->name = (char *)kbasename(ref->full_path->start);
2751 ref->name_len = ref->full_path->end - ref->name;
2755 * We need to process new refs before deleted refs, but compare_tree gives us
2756 * everything mixed. So we first record all refs and later process them.
2757 * This function is a helper to record one ref.
2759 static int __record_ref(struct list_head *head, u64 dir,
2760 u64 dir_gen, struct fs_path *path)
2762 struct recorded_ref *ref;
2764 ref = kmalloc(sizeof(*ref), GFP_KERNEL);
2769 ref->dir_gen = dir_gen;
2770 set_ref_path(ref, path);
2771 list_add_tail(&ref->list, head);
2775 static int dup_ref(struct recorded_ref *ref, struct list_head *list)
2777 struct recorded_ref *new;
2779 new = kmalloc(sizeof(*ref), GFP_KERNEL);
2783 new->dir = ref->dir;
2784 new->dir_gen = ref->dir_gen;
2785 new->full_path = NULL;
2786 INIT_LIST_HEAD(&new->list);
2787 list_add_tail(&new->list, list);
2791 static void __free_recorded_refs(struct list_head *head)
2793 struct recorded_ref *cur;
2795 while (!list_empty(head)) {
2796 cur = list_entry(head->next, struct recorded_ref, list);
2797 fs_path_free(cur->full_path);
2798 list_del(&cur->list);
2803 static void free_recorded_refs(struct send_ctx *sctx)
2805 __free_recorded_refs(&sctx->new_refs);
2806 __free_recorded_refs(&sctx->deleted_refs);
2810 * Renames/moves a file/dir to its orphan name. Used when the first
2811 * ref of an unprocessed inode gets overwritten and for all non empty
2814 static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
2815 struct fs_path *path)
2818 struct fs_path *orphan;
2820 orphan = fs_path_alloc();
2824 ret = gen_unique_name(sctx, ino, gen, orphan);
2828 ret = send_rename(sctx, path, orphan);
2831 fs_path_free(orphan);
2835 static struct orphan_dir_info *
2836 add_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2838 struct rb_node **p = &sctx->orphan_dirs.rb_node;
2839 struct rb_node *parent = NULL;
2840 struct orphan_dir_info *entry, *odi;
2844 entry = rb_entry(parent, struct orphan_dir_info, node);
2845 if (dir_ino < entry->ino) {
2847 } else if (dir_ino > entry->ino) {
2848 p = &(*p)->rb_right;
2854 odi = kmalloc(sizeof(*odi), GFP_KERNEL);
2856 return ERR_PTR(-ENOMEM);
2859 odi->last_dir_index_offset = 0;
2861 rb_link_node(&odi->node, parent, p);
2862 rb_insert_color(&odi->node, &sctx->orphan_dirs);
2866 static struct orphan_dir_info *
2867 get_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2869 struct rb_node *n = sctx->orphan_dirs.rb_node;
2870 struct orphan_dir_info *entry;
2873 entry = rb_entry(n, struct orphan_dir_info, node);
2874 if (dir_ino < entry->ino)
2876 else if (dir_ino > entry->ino)
2884 static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino)
2886 struct orphan_dir_info *odi = get_orphan_dir_info(sctx, dir_ino);
2891 static void free_orphan_dir_info(struct send_ctx *sctx,
2892 struct orphan_dir_info *odi)
2896 rb_erase(&odi->node, &sctx->orphan_dirs);
2901 * Returns 1 if a directory can be removed at this point in time.
2902 * We check this by iterating all dir items and checking if the inode behind
2903 * the dir item was already processed.
2905 static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
2909 struct btrfs_root *root = sctx->parent_root;
2910 struct btrfs_path *path;
2911 struct btrfs_key key;
2912 struct btrfs_key found_key;
2913 struct btrfs_key loc;
2914 struct btrfs_dir_item *di;
2915 struct orphan_dir_info *odi = NULL;
2918 * Don't try to rmdir the top/root subvolume dir.
2920 if (dir == BTRFS_FIRST_FREE_OBJECTID)
2923 path = alloc_path_for_send();
2928 key.type = BTRFS_DIR_INDEX_KEY;
2931 odi = get_orphan_dir_info(sctx, dir);
2933 key.offset = odi->last_dir_index_offset;
2935 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2940 struct waiting_dir_move *dm;
2942 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2943 ret = btrfs_next_leaf(root, path);
2950 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2952 if (found_key.objectid != key.objectid ||
2953 found_key.type != key.type)
2956 di = btrfs_item_ptr(path->nodes[0], path->slots[0],
2957 struct btrfs_dir_item);
2958 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
2960 dm = get_waiting_dir_move(sctx, loc.objectid);
2962 odi = add_orphan_dir_info(sctx, dir);
2968 odi->last_dir_index_offset = found_key.offset;
2969 dm->rmdir_ino = dir;
2974 if (loc.objectid > send_progress) {
2975 odi = add_orphan_dir_info(sctx, dir);
2981 odi->last_dir_index_offset = found_key.offset;
2988 free_orphan_dir_info(sctx, odi);
2993 btrfs_free_path(path);
2997 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
2999 struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino);
3001 return entry != NULL;
3004 static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino, bool orphanized)
3006 struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
3007 struct rb_node *parent = NULL;
3008 struct waiting_dir_move *entry, *dm;
3010 dm = kmalloc(sizeof(*dm), GFP_KERNEL);
3015 dm->orphanized = orphanized;
3019 entry = rb_entry(parent, struct waiting_dir_move, node);
3020 if (ino < entry->ino) {
3022 } else if (ino > entry->ino) {
3023 p = &(*p)->rb_right;
3030 rb_link_node(&dm->node, parent, p);
3031 rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
3035 static struct waiting_dir_move *
3036 get_waiting_dir_move(struct send_ctx *sctx, u64 ino)
3038 struct rb_node *n = sctx->waiting_dir_moves.rb_node;
3039 struct waiting_dir_move *entry;
3042 entry = rb_entry(n, struct waiting_dir_move, node);
3043 if (ino < entry->ino)
3045 else if (ino > entry->ino)
3053 static void free_waiting_dir_move(struct send_ctx *sctx,
3054 struct waiting_dir_move *dm)
3058 rb_erase(&dm->node, &sctx->waiting_dir_moves);
3062 static int add_pending_dir_move(struct send_ctx *sctx,
3066 struct list_head *new_refs,
3067 struct list_head *deleted_refs,
3068 const bool is_orphan)
3070 struct rb_node **p = &sctx->pending_dir_moves.rb_node;
3071 struct rb_node *parent = NULL;
3072 struct pending_dir_move *entry = NULL, *pm;
3073 struct recorded_ref *cur;
3077 pm = kmalloc(sizeof(*pm), GFP_KERNEL);
3080 pm->parent_ino = parent_ino;
3083 INIT_LIST_HEAD(&pm->list);
3084 INIT_LIST_HEAD(&pm->update_refs);
3085 RB_CLEAR_NODE(&pm->node);
3089 entry = rb_entry(parent, struct pending_dir_move, node);
3090 if (parent_ino < entry->parent_ino) {
3092 } else if (parent_ino > entry->parent_ino) {
3093 p = &(*p)->rb_right;
3100 list_for_each_entry(cur, deleted_refs, list) {
3101 ret = dup_ref(cur, &pm->update_refs);
3105 list_for_each_entry(cur, new_refs, list) {
3106 ret = dup_ref(cur, &pm->update_refs);
3111 ret = add_waiting_dir_move(sctx, pm->ino, is_orphan);
3116 list_add_tail(&pm->list, &entry->list);
3118 rb_link_node(&pm->node, parent, p);
3119 rb_insert_color(&pm->node, &sctx->pending_dir_moves);
3124 __free_recorded_refs(&pm->update_refs);
3130 static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
3133 struct rb_node *n = sctx->pending_dir_moves.rb_node;
3134 struct pending_dir_move *entry;
3137 entry = rb_entry(n, struct pending_dir_move, node);
3138 if (parent_ino < entry->parent_ino)
3140 else if (parent_ino > entry->parent_ino)
3148 static int path_loop(struct send_ctx *sctx, struct fs_path *name,
3149 u64 ino, u64 gen, u64 *ancestor_ino)
3152 u64 parent_inode = 0;
3154 u64 start_ino = ino;
3157 while (ino != BTRFS_FIRST_FREE_OBJECTID) {
3158 fs_path_reset(name);
3160 if (is_waiting_for_rm(sctx, ino))
3162 if (is_waiting_for_move(sctx, ino)) {
3163 if (*ancestor_ino == 0)
3164 *ancestor_ino = ino;
3165 ret = get_first_ref(sctx->parent_root, ino,
3166 &parent_inode, &parent_gen, name);
3168 ret = __get_cur_name_and_parent(sctx, ino, gen,
3178 if (parent_inode == start_ino) {
3180 if (*ancestor_ino == 0)
3181 *ancestor_ino = ino;
3190 static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
3192 struct fs_path *from_path = NULL;
3193 struct fs_path *to_path = NULL;
3194 struct fs_path *name = NULL;
3195 u64 orig_progress = sctx->send_progress;
3196 struct recorded_ref *cur;
3197 u64 parent_ino, parent_gen;
3198 struct waiting_dir_move *dm = NULL;
3204 name = fs_path_alloc();
3205 from_path = fs_path_alloc();
3206 if (!name || !from_path) {
3211 dm = get_waiting_dir_move(sctx, pm->ino);
3213 rmdir_ino = dm->rmdir_ino;
3214 is_orphan = dm->orphanized;
3215 free_waiting_dir_move(sctx, dm);
3218 ret = gen_unique_name(sctx, pm->ino,
3219 pm->gen, from_path);
3221 ret = get_first_ref(sctx->parent_root, pm->ino,
3222 &parent_ino, &parent_gen, name);
3225 ret = get_cur_path(sctx, parent_ino, parent_gen,
3229 ret = fs_path_add_path(from_path, name);
3234 sctx->send_progress = sctx->cur_ino + 1;
3235 ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor);
3239 LIST_HEAD(deleted_refs);
3240 ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID);
3241 ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor,
3242 &pm->update_refs, &deleted_refs,
3247 dm = get_waiting_dir_move(sctx, pm->ino);
3249 dm->rmdir_ino = rmdir_ino;
3253 fs_path_reset(name);
3256 ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
3260 ret = send_rename(sctx, from_path, to_path);
3265 struct orphan_dir_info *odi;
3268 odi = get_orphan_dir_info(sctx, rmdir_ino);
3270 /* already deleted */
3275 ret = can_rmdir(sctx, rmdir_ino, gen, sctx->cur_ino);
3281 name = fs_path_alloc();
3286 ret = get_cur_path(sctx, rmdir_ino, gen, name);
3289 ret = send_rmdir(sctx, name);
3295 ret = send_utimes(sctx, pm->ino, pm->gen);
3300 * After rename/move, need to update the utimes of both new parent(s)
3301 * and old parent(s).
3303 list_for_each_entry(cur, &pm->update_refs, list) {
3305 * The parent inode might have been deleted in the send snapshot
3307 ret = get_inode_info(sctx->send_root, cur->dir, NULL,
3308 NULL, NULL, NULL, NULL, NULL);
3309 if (ret == -ENOENT) {
3316 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3323 fs_path_free(from_path);
3324 fs_path_free(to_path);
3325 sctx->send_progress = orig_progress;
3330 static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
3332 if (!list_empty(&m->list))
3334 if (!RB_EMPTY_NODE(&m->node))
3335 rb_erase(&m->node, &sctx->pending_dir_moves);
3336 __free_recorded_refs(&m->update_refs);
3340 static void tail_append_pending_moves(struct send_ctx *sctx,
3341 struct pending_dir_move *moves,
3342 struct list_head *stack)
3344 if (list_empty(&moves->list)) {
3345 list_add_tail(&moves->list, stack);
3348 list_splice_init(&moves->list, &list);
3349 list_add_tail(&moves->list, stack);
3350 list_splice_tail(&list, stack);
3352 if (!RB_EMPTY_NODE(&moves->node)) {
3353 rb_erase(&moves->node, &sctx->pending_dir_moves);
3354 RB_CLEAR_NODE(&moves->node);
3358 static int apply_children_dir_moves(struct send_ctx *sctx)
3360 struct pending_dir_move *pm;
3361 struct list_head stack;
3362 u64 parent_ino = sctx->cur_ino;
3365 pm = get_pending_dir_moves(sctx, parent_ino);
3369 INIT_LIST_HEAD(&stack);
3370 tail_append_pending_moves(sctx, pm, &stack);
3372 while (!list_empty(&stack)) {
3373 pm = list_first_entry(&stack, struct pending_dir_move, list);
3374 parent_ino = pm->ino;
3375 ret = apply_dir_move(sctx, pm);
3376 free_pending_move(sctx, pm);
3379 pm = get_pending_dir_moves(sctx, parent_ino);
3381 tail_append_pending_moves(sctx, pm, &stack);
3386 while (!list_empty(&stack)) {
3387 pm = list_first_entry(&stack, struct pending_dir_move, list);
3388 free_pending_move(sctx, pm);
3394 * We might need to delay a directory rename even when no ancestor directory
3395 * (in the send root) with a higher inode number than ours (sctx->cur_ino) was
3396 * renamed. This happens when we rename a directory to the old name (the name
3397 * in the parent root) of some other unrelated directory that got its rename
3398 * delayed due to some ancestor with higher number that got renamed.
3404 * |---- a/ (ino 257)
3405 * | |---- file (ino 260)
3407 * |---- b/ (ino 258)
3408 * |---- c/ (ino 259)
3412 * |---- a/ (ino 258)
3413 * |---- x/ (ino 259)
3414 * |---- y/ (ino 257)
3415 * |----- file (ino 260)
3417 * Here we can not rename 258 from 'b' to 'a' without the rename of inode 257
3418 * from 'a' to 'x/y' happening first, which in turn depends on the rename of
3419 * inode 259 from 'c' to 'x'. So the order of rename commands the send stream
3422 * 1 - rename 259 from 'c' to 'x'
3423 * 2 - rename 257 from 'a' to 'x/y'
3424 * 3 - rename 258 from 'b' to 'a'
3426 * Returns 1 if the rename of sctx->cur_ino needs to be delayed, 0 if it can
3427 * be done right away and < 0 on error.
3429 static int wait_for_dest_dir_move(struct send_ctx *sctx,
3430 struct recorded_ref *parent_ref,
3431 const bool is_orphan)
3433 struct btrfs_fs_info *fs_info = sctx->parent_root->fs_info;
3434 struct btrfs_path *path;
3435 struct btrfs_key key;
3436 struct btrfs_key di_key;
3437 struct btrfs_dir_item *di;
3441 struct waiting_dir_move *wdm;
3443 if (RB_EMPTY_ROOT(&sctx->waiting_dir_moves))
3446 path = alloc_path_for_send();
3450 key.objectid = parent_ref->dir;
3451 key.type = BTRFS_DIR_ITEM_KEY;
3452 key.offset = btrfs_name_hash(parent_ref->name, parent_ref->name_len);
3454 ret = btrfs_search_slot(NULL, sctx->parent_root, &key, path, 0, 0);
3457 } else if (ret > 0) {
3462 di = btrfs_match_dir_item_name(fs_info, path, parent_ref->name,
3463 parent_ref->name_len);
3469 * di_key.objectid has the number of the inode that has a dentry in the
3470 * parent directory with the same name that sctx->cur_ino is being
3471 * renamed to. We need to check if that inode is in the send root as
3472 * well and if it is currently marked as an inode with a pending rename,
3473 * if it is, we need to delay the rename of sctx->cur_ino as well, so
3474 * that it happens after that other inode is renamed.
3476 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &di_key);
3477 if (di_key.type != BTRFS_INODE_ITEM_KEY) {
3482 ret = get_inode_info(sctx->parent_root, di_key.objectid, NULL,
3483 &left_gen, NULL, NULL, NULL, NULL);
3486 ret = get_inode_info(sctx->send_root, di_key.objectid, NULL,
3487 &right_gen, NULL, NULL, NULL, NULL);
3494 /* Different inode, no need to delay the rename of sctx->cur_ino */
3495 if (right_gen != left_gen) {
3500 wdm = get_waiting_dir_move(sctx, di_key.objectid);
3501 if (wdm && !wdm->orphanized) {
3502 ret = add_pending_dir_move(sctx,
3504 sctx->cur_inode_gen,
3507 &sctx->deleted_refs,
3513 btrfs_free_path(path);
3518 * Check if inode ino2, or any of its ancestors, is inode ino1.
3519 * Return 1 if true, 0 if false and < 0 on error.
3521 static int check_ino_in_path(struct btrfs_root *root,
3526 struct fs_path *fs_path)
3531 return ino1_gen == ino2_gen;
3533 while (ino > BTRFS_FIRST_FREE_OBJECTID) {
3538 fs_path_reset(fs_path);
3539 ret = get_first_ref(root, ino, &parent, &parent_gen, fs_path);
3543 return parent_gen == ino1_gen;
3550 * Check if ino ino1 is an ancestor of inode ino2 in the given root for any
3551 * possible path (in case ino2 is not a directory and has multiple hard links).
3552 * Return 1 if true, 0 if false and < 0 on error.
3554 static int is_ancestor(struct btrfs_root *root,
3558 struct fs_path *fs_path)
3560 bool free_fs_path = false;
3562 struct btrfs_path *path = NULL;
3563 struct btrfs_key key;
3566 fs_path = fs_path_alloc();
3569 free_fs_path = true;
3572 path = alloc_path_for_send();
3578 key.objectid = ino2;
3579 key.type = BTRFS_INODE_REF_KEY;
3582 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3587 struct extent_buffer *leaf = path->nodes[0];
3588 int slot = path->slots[0];
3592 if (slot >= btrfs_header_nritems(leaf)) {
3593 ret = btrfs_next_leaf(root, path);
3601 btrfs_item_key_to_cpu(leaf, &key, slot);
3602 if (key.objectid != ino2)
3604 if (key.type != BTRFS_INODE_REF_KEY &&
3605 key.type != BTRFS_INODE_EXTREF_KEY)
3608 item_size = btrfs_item_size_nr(leaf, slot);
3609 while (cur_offset < item_size) {
3613 if (key.type == BTRFS_INODE_EXTREF_KEY) {
3615 struct btrfs_inode_extref *extref;
3617 ptr = btrfs_item_ptr_offset(leaf, slot);
3618 extref = (struct btrfs_inode_extref *)
3620 parent = btrfs_inode_extref_parent(leaf,
3622 cur_offset += sizeof(*extref);
3623 cur_offset += btrfs_inode_extref_name_len(leaf,
3626 parent = key.offset;
3627 cur_offset = item_size;
3630 ret = get_inode_info(root, parent, NULL, &parent_gen,
3631 NULL, NULL, NULL, NULL);
3634 ret = check_ino_in_path(root, ino1, ino1_gen,
3635 parent, parent_gen, fs_path);
3643 btrfs_free_path(path);
3645 fs_path_free(fs_path);
3649 static int wait_for_parent_move(struct send_ctx *sctx,
3650 struct recorded_ref *parent_ref,
3651 const bool is_orphan)
3654 u64 ino = parent_ref->dir;
3655 u64 ino_gen = parent_ref->dir_gen;
3656 u64 parent_ino_before, parent_ino_after;
3657 struct fs_path *path_before = NULL;
3658 struct fs_path *path_after = NULL;
3661 path_after = fs_path_alloc();
3662 path_before = fs_path_alloc();
3663 if (!path_after || !path_before) {
3669 * Our current directory inode may not yet be renamed/moved because some
3670 * ancestor (immediate or not) has to be renamed/moved first. So find if
3671 * such ancestor exists and make sure our own rename/move happens after
3672 * that ancestor is processed to avoid path build infinite loops (done
3673 * at get_cur_path()).
3675 while (ino > BTRFS_FIRST_FREE_OBJECTID) {
3676 u64 parent_ino_after_gen;
3678 if (is_waiting_for_move(sctx, ino)) {
3680 * If the current inode is an ancestor of ino in the
3681 * parent root, we need to delay the rename of the
3682 * current inode, otherwise don't delayed the rename
3683 * because we can end up with a circular dependency
3684 * of renames, resulting in some directories never
3685 * getting the respective rename operations issued in
3686 * the send stream or getting into infinite path build
3689 ret = is_ancestor(sctx->parent_root,
3690 sctx->cur_ino, sctx->cur_inode_gen,
3696 fs_path_reset(path_before);
3697 fs_path_reset(path_after);
3699 ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3700 &parent_ino_after_gen, path_after);
3703 ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
3705 if (ret < 0 && ret != -ENOENT) {
3707 } else if (ret == -ENOENT) {
3712 len1 = fs_path_len(path_before);
3713 len2 = fs_path_len(path_after);
3714 if (ino > sctx->cur_ino &&
3715 (parent_ino_before != parent_ino_after || len1 != len2 ||
3716 memcmp(path_before->start, path_after->start, len1))) {
3719 ret = get_inode_info(sctx->parent_root, ino, NULL,
3720 &parent_ino_gen, NULL, NULL, NULL,
3724 if (ino_gen == parent_ino_gen) {
3729 ino = parent_ino_after;
3730 ino_gen = parent_ino_after_gen;
3734 fs_path_free(path_before);
3735 fs_path_free(path_after);
3738 ret = add_pending_dir_move(sctx,
3740 sctx->cur_inode_gen,
3743 &sctx->deleted_refs,
3752 static int update_ref_path(struct send_ctx *sctx, struct recorded_ref *ref)
3755 struct fs_path *new_path;
3758 * Our reference's name member points to its full_path member string, so
3759 * we use here a new path.
3761 new_path = fs_path_alloc();
3765 ret = get_cur_path(sctx, ref->dir, ref->dir_gen, new_path);
3767 fs_path_free(new_path);
3770 ret = fs_path_add(new_path, ref->name, ref->name_len);
3772 fs_path_free(new_path);
3776 fs_path_free(ref->full_path);
3777 set_ref_path(ref, new_path);
3783 * This does all the move/link/unlink/rmdir magic.
3785 static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
3787 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
3789 struct recorded_ref *cur;
3790 struct recorded_ref *cur2;
3791 struct list_head check_dirs;
3792 struct fs_path *valid_path = NULL;
3796 int did_overwrite = 0;
3798 u64 last_dir_ino_rm = 0;
3799 bool can_rename = true;
3800 bool orphanized_dir = false;
3801 bool orphanized_ancestor = false;
3803 btrfs_debug(fs_info, "process_recorded_refs %llu", sctx->cur_ino);
3806 * This should never happen as the root dir always has the same ref
3807 * which is always '..'
3809 BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
3810 INIT_LIST_HEAD(&check_dirs);
3812 valid_path = fs_path_alloc();
3819 * First, check if the first ref of the current inode was overwritten
3820 * before. If yes, we know that the current inode was already orphanized
3821 * and thus use the orphan name. If not, we can use get_cur_path to
3822 * get the path of the first ref as it would like while receiving at
3823 * this point in time.
3824 * New inodes are always orphan at the beginning, so force to use the
3825 * orphan name in this case.
3826 * The first ref is stored in valid_path and will be updated if it
3827 * gets moved around.
3829 if (!sctx->cur_inode_new) {
3830 ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
3831 sctx->cur_inode_gen);
3837 if (sctx->cur_inode_new || did_overwrite) {
3838 ret = gen_unique_name(sctx, sctx->cur_ino,
3839 sctx->cur_inode_gen, valid_path);
3844 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3850 list_for_each_entry(cur, &sctx->new_refs, list) {
3852 * We may have refs where the parent directory does not exist
3853 * yet. This happens if the parent directories inum is higher
3854 * than the current inum. To handle this case, we create the
3855 * parent directory out of order. But we need to check if this
3856 * did already happen before due to other refs in the same dir.
3858 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3861 if (ret == inode_state_will_create) {
3864 * First check if any of the current inodes refs did
3865 * already create the dir.
3867 list_for_each_entry(cur2, &sctx->new_refs, list) {
3870 if (cur2->dir == cur->dir) {
3877 * If that did not happen, check if a previous inode
3878 * did already create the dir.
3881 ret = did_create_dir(sctx, cur->dir);
3885 ret = send_create_inode(sctx, cur->dir);
3892 * Check if this new ref would overwrite the first ref of
3893 * another unprocessed inode. If yes, orphanize the
3894 * overwritten inode. If we find an overwritten ref that is
3895 * not the first ref, simply unlink it.
3897 ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3898 cur->name, cur->name_len,
3899 &ow_inode, &ow_gen, &ow_mode);
3903 ret = is_first_ref(sctx->parent_root,
3904 ow_inode, cur->dir, cur->name,
3909 struct name_cache_entry *nce;
3910 struct waiting_dir_move *wdm;
3912 ret = orphanize_inode(sctx, ow_inode, ow_gen,
3916 if (S_ISDIR(ow_mode))
3917 orphanized_dir = true;
3920 * If ow_inode has its rename operation delayed
3921 * make sure that its orphanized name is used in
3922 * the source path when performing its rename
3925 if (is_waiting_for_move(sctx, ow_inode)) {
3926 wdm = get_waiting_dir_move(sctx,
3929 wdm->orphanized = true;
3933 * Make sure we clear our orphanized inode's
3934 * name from the name cache. This is because the
3935 * inode ow_inode might be an ancestor of some
3936 * other inode that will be orphanized as well
3937 * later and has an inode number greater than
3938 * sctx->send_progress. We need to prevent
3939 * future name lookups from using the old name
3940 * and get instead the orphan name.
3942 nce = name_cache_search(sctx, ow_inode, ow_gen);
3944 name_cache_delete(sctx, nce);
3949 * ow_inode might currently be an ancestor of
3950 * cur_ino, therefore compute valid_path (the
3951 * current path of cur_ino) again because it
3952 * might contain the pre-orphanization name of
3953 * ow_inode, which is no longer valid.
3955 ret = is_ancestor(sctx->parent_root,
3957 sctx->cur_ino, NULL);
3959 orphanized_ancestor = true;
3960 fs_path_reset(valid_path);
3961 ret = get_cur_path(sctx, sctx->cur_ino,
3962 sctx->cur_inode_gen,
3968 ret = send_unlink(sctx, cur->full_path);
3974 if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root) {
3975 ret = wait_for_dest_dir_move(sctx, cur, is_orphan);
3984 if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root &&
3986 ret = wait_for_parent_move(sctx, cur, is_orphan);
3996 * link/move the ref to the new place. If we have an orphan
3997 * inode, move it and update valid_path. If not, link or move
3998 * it depending on the inode mode.
4000 if (is_orphan && can_rename) {
4001 ret = send_rename(sctx, valid_path, cur->full_path);
4005 ret = fs_path_copy(valid_path, cur->full_path);
4008 } else if (can_rename) {
4009 if (S_ISDIR(sctx->cur_inode_mode)) {
4011 * Dirs can't be linked, so move it. For moved
4012 * dirs, we always have one new and one deleted
4013 * ref. The deleted ref is ignored later.
4015 ret = send_rename(sctx, valid_path,
4018 ret = fs_path_copy(valid_path,
4024 * We might have previously orphanized an inode
4025 * which is an ancestor of our current inode,
4026 * so our reference's full path, which was
4027 * computed before any such orphanizations, must
4030 if (orphanized_dir) {
4031 ret = update_ref_path(sctx, cur);
4035 ret = send_link(sctx, cur->full_path,
4041 ret = dup_ref(cur, &check_dirs);
4046 if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
4048 * Check if we can already rmdir the directory. If not,
4049 * orphanize it. For every dir item inside that gets deleted
4050 * later, we do this check again and rmdir it then if possible.
4051 * See the use of check_dirs for more details.
4053 ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4058 ret = send_rmdir(sctx, valid_path);
4061 } else if (!is_orphan) {
4062 ret = orphanize_inode(sctx, sctx->cur_ino,
4063 sctx->cur_inode_gen, valid_path);
4069 list_for_each_entry(cur, &sctx->deleted_refs, list) {
4070 ret = dup_ref(cur, &check_dirs);
4074 } else if (S_ISDIR(sctx->cur_inode_mode) &&
4075 !list_empty(&sctx->deleted_refs)) {
4077 * We have a moved dir. Add the old parent to check_dirs
4079 cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
4081 ret = dup_ref(cur, &check_dirs);
4084 } else if (!S_ISDIR(sctx->cur_inode_mode)) {
4086 * We have a non dir inode. Go through all deleted refs and
4087 * unlink them if they were not already overwritten by other
4090 list_for_each_entry(cur, &sctx->deleted_refs, list) {
4091 ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
4092 sctx->cur_ino, sctx->cur_inode_gen,
4093 cur->name, cur->name_len);
4098 * If we orphanized any ancestor before, we need
4099 * to recompute the full path for deleted names,
4100 * since any such path was computed before we
4101 * processed any references and orphanized any
4104 if (orphanized_ancestor) {
4105 ret = update_ref_path(sctx, cur);
4109 ret = send_unlink(sctx, cur->full_path);
4113 ret = dup_ref(cur, &check_dirs);
4118 * If the inode is still orphan, unlink the orphan. This may
4119 * happen when a previous inode did overwrite the first ref
4120 * of this inode and no new refs were added for the current
4121 * inode. Unlinking does not mean that the inode is deleted in
4122 * all cases. There may still be links to this inode in other
4126 ret = send_unlink(sctx, valid_path);
4133 * We did collect all parent dirs where cur_inode was once located. We
4134 * now go through all these dirs and check if they are pending for
4135 * deletion and if it's finally possible to perform the rmdir now.
4136 * We also update the inode stats of the parent dirs here.
4138 list_for_each_entry(cur, &check_dirs, list) {
4140 * In case we had refs into dirs that were not processed yet,
4141 * we don't need to do the utime and rmdir logic for these dirs.
4142 * The dir will be processed later.
4144 if (cur->dir > sctx->cur_ino)
4147 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
4151 if (ret == inode_state_did_create ||
4152 ret == inode_state_no_change) {
4153 /* TODO delayed utimes */
4154 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
4157 } else if (ret == inode_state_did_delete &&
4158 cur->dir != last_dir_ino_rm) {
4159 ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
4164 ret = get_cur_path(sctx, cur->dir,
4165 cur->dir_gen, valid_path);
4168 ret = send_rmdir(sctx, valid_path);
4171 last_dir_ino_rm = cur->dir;
4179 __free_recorded_refs(&check_dirs);
4180 free_recorded_refs(sctx);
4181 fs_path_free(valid_path);
4185 static int record_ref(struct btrfs_root *root, u64 dir, struct fs_path *name,
4186 void *ctx, struct list_head *refs)
4189 struct send_ctx *sctx = ctx;
4193 p = fs_path_alloc();
4197 ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
4202 ret = get_cur_path(sctx, dir, gen, p);
4205 ret = fs_path_add_path(p, name);
4209 ret = __record_ref(refs, dir, gen, p);
4217 static int __record_new_ref(int num, u64 dir, int index,
4218 struct fs_path *name,
4221 struct send_ctx *sctx = ctx;
4222 return record_ref(sctx->send_root, dir, name, ctx, &sctx->new_refs);
4226 static int __record_deleted_ref(int num, u64 dir, int index,
4227 struct fs_path *name,
4230 struct send_ctx *sctx = ctx;
4231 return record_ref(sctx->parent_root, dir, name, ctx,
4232 &sctx->deleted_refs);
4235 static int record_new_ref(struct send_ctx *sctx)
4239 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
4240 sctx->cmp_key, 0, __record_new_ref, sctx);
4249 static int record_deleted_ref(struct send_ctx *sctx)
4253 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
4254 sctx->cmp_key, 0, __record_deleted_ref, sctx);
4263 struct find_ref_ctx {
4266 struct btrfs_root *root;
4267 struct fs_path *name;
4271 static int __find_iref(int num, u64 dir, int index,
4272 struct fs_path *name,
4275 struct find_ref_ctx *ctx = ctx_;
4279 if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
4280 strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
4282 * To avoid doing extra lookups we'll only do this if everything
4285 ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
4289 if (dir_gen != ctx->dir_gen)
4291 ctx->found_idx = num;
4297 static int find_iref(struct btrfs_root *root,
4298 struct btrfs_path *path,
4299 struct btrfs_key *key,
4300 u64 dir, u64 dir_gen, struct fs_path *name)
4303 struct find_ref_ctx ctx;
4307 ctx.dir_gen = dir_gen;
4311 ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
4315 if (ctx.found_idx == -1)
4318 return ctx.found_idx;
4321 static int __record_changed_new_ref(int num, u64 dir, int index,
4322 struct fs_path *name,
4327 struct send_ctx *sctx = ctx;
4329 ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
4334 ret = find_iref(sctx->parent_root, sctx->right_path,
4335 sctx->cmp_key, dir, dir_gen, name);
4337 ret = __record_new_ref(num, dir, index, name, sctx);
4344 static int __record_changed_deleted_ref(int num, u64 dir, int index,
4345 struct fs_path *name,
4350 struct send_ctx *sctx = ctx;
4352 ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
4357 ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
4358 dir, dir_gen, name);
4360 ret = __record_deleted_ref(num, dir, index, name, sctx);
4367 static int record_changed_ref(struct send_ctx *sctx)
4371 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
4372 sctx->cmp_key, 0, __record_changed_new_ref, sctx);
4375 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
4376 sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
4386 * Record and process all refs at once. Needed when an inode changes the
4387 * generation number, which means that it was deleted and recreated.
4389 static int process_all_refs(struct send_ctx *sctx,
4390 enum btrfs_compare_tree_result cmd)
4393 struct btrfs_root *root;
4394 struct btrfs_path *path;
4395 struct btrfs_key key;
4396 struct btrfs_key found_key;
4397 struct extent_buffer *eb;
4399 iterate_inode_ref_t cb;
4400 int pending_move = 0;
4402 path = alloc_path_for_send();
4406 if (cmd == BTRFS_COMPARE_TREE_NEW) {
4407 root = sctx->send_root;
4408 cb = __record_new_ref;
4409 } else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
4410 root = sctx->parent_root;
4411 cb = __record_deleted_ref;
4413 btrfs_err(sctx->send_root->fs_info,
4414 "Wrong command %d in process_all_refs", cmd);
4419 key.objectid = sctx->cmp_key->objectid;
4420 key.type = BTRFS_INODE_REF_KEY;
4422 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4427 eb = path->nodes[0];
4428 slot = path->slots[0];
4429 if (slot >= btrfs_header_nritems(eb)) {
4430 ret = btrfs_next_leaf(root, path);
4438 btrfs_item_key_to_cpu(eb, &found_key, slot);
4440 if (found_key.objectid != key.objectid ||
4441 (found_key.type != BTRFS_INODE_REF_KEY &&
4442 found_key.type != BTRFS_INODE_EXTREF_KEY))
4445 ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
4451 btrfs_release_path(path);
4454 * We don't actually care about pending_move as we are simply
4455 * re-creating this inode and will be rename'ing it into place once we
4456 * rename the parent directory.
4458 ret = process_recorded_refs(sctx, &pending_move);
4460 btrfs_free_path(path);
4464 static int send_set_xattr(struct send_ctx *sctx,
4465 struct fs_path *path,
4466 const char *name, int name_len,
4467 const char *data, int data_len)
4471 ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
4475 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
4476 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
4477 TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
4479 ret = send_cmd(sctx);
4486 static int send_remove_xattr(struct send_ctx *sctx,
4487 struct fs_path *path,
4488 const char *name, int name_len)
4492 ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
4496 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
4497 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
4499 ret = send_cmd(sctx);
4506 static int __process_new_xattr(int num, struct btrfs_key *di_key,
4507 const char *name, int name_len,
4508 const char *data, int data_len,
4512 struct send_ctx *sctx = ctx;
4514 struct posix_acl_xattr_header dummy_acl;
4516 p = fs_path_alloc();
4521 * This hack is needed because empty acls are stored as zero byte
4522 * data in xattrs. Problem with that is, that receiving these zero byte
4523 * acls will fail later. To fix this, we send a dummy acl list that
4524 * only contains the version number and no entries.
4526 if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
4527 !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
4528 if (data_len == 0) {
4529 dummy_acl.a_version =
4530 cpu_to_le32(POSIX_ACL_XATTR_VERSION);
4531 data = (char *)&dummy_acl;
4532 data_len = sizeof(dummy_acl);
4536 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4540 ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
4547 static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
4548 const char *name, int name_len,
4549 const char *data, int data_len,
4553 struct send_ctx *sctx = ctx;
4556 p = fs_path_alloc();
4560 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4564 ret = send_remove_xattr(sctx, p, name, name_len);
4571 static int process_new_xattr(struct send_ctx *sctx)
4575 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4576 __process_new_xattr, sctx);
4581 static int process_deleted_xattr(struct send_ctx *sctx)
4583 return iterate_dir_item(sctx->parent_root, sctx->right_path,
4584 __process_deleted_xattr, sctx);
4587 struct find_xattr_ctx {
4595 static int __find_xattr(int num, struct btrfs_key *di_key,
4596 const char *name, int name_len,
4597 const char *data, int data_len,
4598 u8 type, void *vctx)
4600 struct find_xattr_ctx *ctx = vctx;
4602 if (name_len == ctx->name_len &&
4603 strncmp(name, ctx->name, name_len) == 0) {
4604 ctx->found_idx = num;
4605 ctx->found_data_len = data_len;
4606 ctx->found_data = kmemdup(data, data_len, GFP_KERNEL);
4607 if (!ctx->found_data)
4614 static int find_xattr(struct btrfs_root *root,
4615 struct btrfs_path *path,
4616 struct btrfs_key *key,
4617 const char *name, int name_len,
4618 char **data, int *data_len)
4621 struct find_xattr_ctx ctx;
4624 ctx.name_len = name_len;
4626 ctx.found_data = NULL;
4627 ctx.found_data_len = 0;
4629 ret = iterate_dir_item(root, path, __find_xattr, &ctx);
4633 if (ctx.found_idx == -1)
4636 *data = ctx.found_data;
4637 *data_len = ctx.found_data_len;
4639 kfree(ctx.found_data);
4641 return ctx.found_idx;
4645 static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
4646 const char *name, int name_len,
4647 const char *data, int data_len,
4651 struct send_ctx *sctx = ctx;
4652 char *found_data = NULL;
4653 int found_data_len = 0;
4655 ret = find_xattr(sctx->parent_root, sctx->right_path,
4656 sctx->cmp_key, name, name_len, &found_data,
4658 if (ret == -ENOENT) {
4659 ret = __process_new_xattr(num, di_key, name, name_len, data,
4660 data_len, type, ctx);
4661 } else if (ret >= 0) {
4662 if (data_len != found_data_len ||
4663 memcmp(data, found_data, data_len)) {
4664 ret = __process_new_xattr(num, di_key, name, name_len,
4665 data, data_len, type, ctx);
4675 static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
4676 const char *name, int name_len,
4677 const char *data, int data_len,
4681 struct send_ctx *sctx = ctx;
4683 ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
4684 name, name_len, NULL, NULL);
4686 ret = __process_deleted_xattr(num, di_key, name, name_len, data,
4687 data_len, type, ctx);
4694 static int process_changed_xattr(struct send_ctx *sctx)
4698 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4699 __process_changed_new_xattr, sctx);
4702 ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4703 __process_changed_deleted_xattr, sctx);
4709 static int process_all_new_xattrs(struct send_ctx *sctx)
4712 struct btrfs_root *root;
4713 struct btrfs_path *path;
4714 struct btrfs_key key;
4715 struct btrfs_key found_key;
4716 struct extent_buffer *eb;
4719 path = alloc_path_for_send();
4723 root = sctx->send_root;
4725 key.objectid = sctx->cmp_key->objectid;
4726 key.type = BTRFS_XATTR_ITEM_KEY;
4728 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4733 eb = path->nodes[0];
4734 slot = path->slots[0];
4735 if (slot >= btrfs_header_nritems(eb)) {
4736 ret = btrfs_next_leaf(root, path);
4739 } else if (ret > 0) {
4746 btrfs_item_key_to_cpu(eb, &found_key, slot);
4747 if (found_key.objectid != key.objectid ||
4748 found_key.type != key.type) {
4753 ret = iterate_dir_item(root, path, __process_new_xattr, sctx);
4761 btrfs_free_path(path);
4765 static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
4767 struct btrfs_root *root = sctx->send_root;
4768 struct btrfs_fs_info *fs_info = root->fs_info;
4769 struct inode *inode;
4772 struct btrfs_key key;
4773 pgoff_t index = offset >> PAGE_SHIFT;
4775 unsigned pg_offset = offset_in_page(offset);
4778 key.objectid = sctx->cur_ino;
4779 key.type = BTRFS_INODE_ITEM_KEY;
4782 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
4784 return PTR_ERR(inode);
4786 if (offset + len > i_size_read(inode)) {
4787 if (offset > i_size_read(inode))
4790 len = offset - i_size_read(inode);
4795 last_index = (offset + len - 1) >> PAGE_SHIFT;
4797 /* initial readahead */
4798 memset(&sctx->ra, 0, sizeof(struct file_ra_state));
4799 file_ra_state_init(&sctx->ra, inode->i_mapping);
4801 while (index <= last_index) {
4802 unsigned cur_len = min_t(unsigned, len,
4803 PAGE_SIZE - pg_offset);
4805 page = find_lock_page(inode->i_mapping, index);
4807 page_cache_sync_readahead(inode->i_mapping, &sctx->ra,
4808 NULL, index, last_index + 1 - index);
4810 page = find_or_create_page(inode->i_mapping, index,
4818 if (PageReadahead(page)) {
4819 page_cache_async_readahead(inode->i_mapping, &sctx->ra,
4820 NULL, page, index, last_index + 1 - index);
4823 if (!PageUptodate(page)) {
4824 btrfs_readpage(NULL, page);
4826 if (!PageUptodate(page)) {
4835 memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len);
4850 * Read some bytes from the current inode/file and send a write command to
4853 static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
4855 struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
4858 ssize_t num_read = 0;
4860 p = fs_path_alloc();
4864 btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len);
4866 num_read = fill_read_buf(sctx, offset, len);
4867 if (num_read <= 0) {
4873 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4877 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4881 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4882 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4883 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
4885 ret = send_cmd(sctx);
4896 * Send a clone command to user space.
4898 static int send_clone(struct send_ctx *sctx,
4899 u64 offset, u32 len,
4900 struct clone_root *clone_root)
4906 btrfs_debug(sctx->send_root->fs_info,
4907 "send_clone offset=%llu, len=%d, clone_root=%llu, clone_inode=%llu, clone_offset=%llu",
4908 offset, len, clone_root->root->root_key.objectid,
4909 clone_root->ino, clone_root->offset);
4911 p = fs_path_alloc();
4915 ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
4919 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4923 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4924 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
4925 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4927 if (clone_root->root == sctx->send_root) {
4928 ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
4929 &gen, NULL, NULL, NULL, NULL);
4932 ret = get_cur_path(sctx, clone_root->ino, gen, p);
4934 ret = get_inode_path(clone_root->root, clone_root->ino, p);
4940 * If the parent we're using has a received_uuid set then use that as
4941 * our clone source as that is what we will look for when doing a
4944 * This covers the case that we create a snapshot off of a received
4945 * subvolume and then use that as the parent and try to receive on a
4948 if (!btrfs_is_empty_uuid(clone_root->root->root_item.received_uuid))
4949 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4950 clone_root->root->root_item.received_uuid);
4952 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4953 clone_root->root->root_item.uuid);
4954 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
4955 le64_to_cpu(clone_root->root->root_item.ctransid));
4956 TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
4957 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
4958 clone_root->offset);
4960 ret = send_cmd(sctx);
4969 * Send an update extent command to user space.
4971 static int send_update_extent(struct send_ctx *sctx,
4972 u64 offset, u32 len)
4977 p = fs_path_alloc();
4981 ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
4985 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4989 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4990 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4991 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);
4993 ret = send_cmd(sctx);
5001 static int send_hole(struct send_ctx *sctx, u64 end)
5003 struct fs_path *p = NULL;
5004 u64 offset = sctx->cur_inode_last_extent;
5009 * A hole that starts at EOF or beyond it. Since we do not yet support
5010 * fallocate (for extent preallocation and hole punching), sending a
5011 * write of zeroes starting at EOF or beyond would later require issuing
5012 * a truncate operation which would undo the write and achieve nothing.
5014 if (offset >= sctx->cur_inode_size)
5018 * Don't go beyond the inode's i_size due to prealloc extents that start
5021 end = min_t(u64, end, sctx->cur_inode_size);
5023 if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
5024 return send_update_extent(sctx, offset, end - offset);
5026 p = fs_path_alloc();
5029 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
5031 goto tlv_put_failure;
5032 memset(sctx->read_buf, 0, BTRFS_SEND_READ_SIZE);
5033 while (offset < end) {
5034 len = min_t(u64, end - offset, BTRFS_SEND_READ_SIZE);
5036 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
5039 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
5040 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
5041 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len);
5042 ret = send_cmd(sctx);
5047 sctx->cur_inode_next_write_offset = offset;
5053 static int send_extent_data(struct send_ctx *sctx,
5059 if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA)
5060 return send_update_extent(sctx, offset, len);
5062 while (sent < len) {
5063 u64 size = len - sent;
5066 if (size > BTRFS_SEND_READ_SIZE)
5067 size = BTRFS_SEND_READ_SIZE;
5068 ret = send_write(sctx, offset + sent, size);
5078 static int clone_range(struct send_ctx *sctx,
5079 struct clone_root *clone_root,
5080 const u64 disk_byte,
5085 struct btrfs_path *path;
5086 struct btrfs_key key;
5088 u64 clone_src_i_size;
5091 * Prevent cloning from a zero offset with a length matching the sector
5092 * size because in some scenarios this will make the receiver fail.
5094 * For example, if in the source filesystem the extent at offset 0
5095 * has a length of sectorsize and it was written using direct IO, then
5096 * it can never be an inline extent (even if compression is enabled).
5097 * Then this extent can be cloned in the original filesystem to a non
5098 * zero file offset, but it may not be possible to clone in the
5099 * destination filesystem because it can be inlined due to compression
5100 * on the destination filesystem (as the receiver's write operations are
5101 * always done using buffered IO). The same happens when the original
5102 * filesystem does not have compression enabled but the destination
5105 if (clone_root->offset == 0 &&
5106 len == sctx->send_root->fs_info->sectorsize)
5107 return send_extent_data(sctx, offset, len);
5109 path = alloc_path_for_send();
5114 * There are inodes that have extents that lie behind its i_size. Don't
5115 * accept clones from these extents.
5117 ret = __get_inode_info(clone_root->root, path, clone_root->ino,
5118 &clone_src_i_size, NULL, NULL, NULL, NULL, NULL);
5119 btrfs_release_path(path);
5124 * We can't send a clone operation for the entire range if we find
5125 * extent items in the respective range in the source file that
5126 * refer to different extents or if we find holes.
5127 * So check for that and do a mix of clone and regular write/copy
5128 * operations if needed.
5132 * mkfs.btrfs -f /dev/sda
5133 * mount /dev/sda /mnt
5134 * xfs_io -f -c "pwrite -S 0xaa 0K 100K" /mnt/foo
5135 * cp --reflink=always /mnt/foo /mnt/bar
5136 * xfs_io -c "pwrite -S 0xbb 50K 50K" /mnt/foo
5137 * btrfs subvolume snapshot -r /mnt /mnt/snap
5139 * If when we send the snapshot and we are processing file bar (which
5140 * has a higher inode number than foo) we blindly send a clone operation
5141 * for the [0, 100K[ range from foo to bar, the receiver ends up getting
5142 * a file bar that matches the content of file foo - iow, doesn't match
5143 * the content from bar in the original filesystem.
5145 key.objectid = clone_root->ino;
5146 key.type = BTRFS_EXTENT_DATA_KEY;
5147 key.offset = clone_root->offset;
5148 ret = btrfs_search_slot(NULL, clone_root->root, &key, path, 0, 0);
5151 if (ret > 0 && path->slots[0] > 0) {
5152 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
5153 if (key.objectid == clone_root->ino &&
5154 key.type == BTRFS_EXTENT_DATA_KEY)
5159 struct extent_buffer *leaf = path->nodes[0];
5160 int slot = path->slots[0];
5161 struct btrfs_file_extent_item *ei;
5165 u64 clone_data_offset;
5167 if (slot >= btrfs_header_nritems(leaf)) {
5168 ret = btrfs_next_leaf(clone_root->root, path);
5176 btrfs_item_key_to_cpu(leaf, &key, slot);
5179 * We might have an implicit trailing hole (NO_HOLES feature
5180 * enabled). We deal with it after leaving this loop.
5182 if (key.objectid != clone_root->ino ||
5183 key.type != BTRFS_EXTENT_DATA_KEY)
5186 ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5187 type = btrfs_file_extent_type(leaf, ei);
5188 if (type == BTRFS_FILE_EXTENT_INLINE) {
5189 ext_len = btrfs_file_extent_ram_bytes(leaf, ei);
5190 ext_len = PAGE_ALIGN(ext_len);
5192 ext_len = btrfs_file_extent_num_bytes(leaf, ei);
5195 if (key.offset + ext_len <= clone_root->offset)
5198 if (key.offset > clone_root->offset) {
5199 /* Implicit hole, NO_HOLES feature enabled. */
5200 u64 hole_len = key.offset - clone_root->offset;
5204 ret = send_extent_data(sctx, offset, hole_len);
5212 clone_root->offset += hole_len;
5213 data_offset += hole_len;
5216 if (key.offset >= clone_root->offset + len)
5219 if (key.offset >= clone_src_i_size)
5222 if (key.offset + ext_len > clone_src_i_size)
5223 ext_len = clone_src_i_size - key.offset;
5225 clone_data_offset = btrfs_file_extent_offset(leaf, ei);
5226 if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte) {
5227 clone_root->offset = key.offset;
5228 if (clone_data_offset < data_offset &&
5229 clone_data_offset + ext_len > data_offset) {
5232 extent_offset = data_offset - clone_data_offset;
5233 ext_len -= extent_offset;
5234 clone_data_offset += extent_offset;
5235 clone_root->offset += extent_offset;
5239 clone_len = min_t(u64, ext_len, len);
5241 if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte &&
5242 clone_data_offset == data_offset) {
5243 const u64 src_end = clone_root->offset + clone_len;
5244 const u64 sectorsize = SZ_64K;
5247 * We can't clone the last block, when its size is not
5248 * sector size aligned, into the middle of a file. If we
5249 * do so, the receiver will get a failure (-EINVAL) when
5250 * trying to clone or will silently corrupt the data in
5251 * the destination file if it's on a kernel without the
5252 * fix introduced by commit ac765f83f1397646
5253 * ("Btrfs: fix data corruption due to cloning of eof
5256 * So issue a clone of the aligned down range plus a
5257 * regular write for the eof block, if we hit that case.
5259 * Also, we use the maximum possible sector size, 64K,
5260 * because we don't know what's the sector size of the
5261 * filesystem that receives the stream, so we have to
5262 * assume the largest possible sector size.
5264 if (src_end == clone_src_i_size &&
5265 !IS_ALIGNED(src_end, sectorsize) &&
5266 offset + clone_len < sctx->cur_inode_size) {
5269 slen = ALIGN_DOWN(src_end - clone_root->offset,
5272 ret = send_clone(sctx, offset, slen,
5277 ret = send_extent_data(sctx, offset + slen,
5280 ret = send_clone(sctx, offset, clone_len,
5284 ret = send_extent_data(sctx, offset, clone_len);
5293 offset += clone_len;
5294 clone_root->offset += clone_len;
5295 data_offset += clone_len;
5301 ret = send_extent_data(sctx, offset, len);
5305 btrfs_free_path(path);
5309 static int send_write_or_clone(struct send_ctx *sctx,
5310 struct btrfs_path *path,
5311 struct btrfs_key *key,
5312 struct clone_root *clone_root)
5315 struct btrfs_file_extent_item *ei;
5316 u64 offset = key->offset;
5319 u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
5321 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
5322 struct btrfs_file_extent_item);
5323 type = btrfs_file_extent_type(path->nodes[0], ei);
5324 if (type == BTRFS_FILE_EXTENT_INLINE) {
5325 len = btrfs_file_extent_ram_bytes(path->nodes[0], ei);
5327 * it is possible the inline item won't cover the whole page,
5328 * but there may be items after this page. Make
5329 * sure to send the whole thing
5331 len = PAGE_ALIGN(len);
5333 len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
5336 if (offset >= sctx->cur_inode_size) {
5340 if (offset + len > sctx->cur_inode_size)
5341 len = sctx->cur_inode_size - offset;
5347 if (clone_root && IS_ALIGNED(offset + len, bs)) {
5351 disk_byte = btrfs_file_extent_disk_bytenr(path->nodes[0], ei);
5352 data_offset = btrfs_file_extent_offset(path->nodes[0], ei);
5353 ret = clone_range(sctx, clone_root, disk_byte, data_offset,
5356 ret = send_extent_data(sctx, offset, len);
5358 sctx->cur_inode_next_write_offset = offset + len;
5363 static int is_extent_unchanged(struct send_ctx *sctx,
5364 struct btrfs_path *left_path,
5365 struct btrfs_key *ekey)
5368 struct btrfs_key key;
5369 struct btrfs_path *path = NULL;
5370 struct extent_buffer *eb;
5372 struct btrfs_key found_key;
5373 struct btrfs_file_extent_item *ei;
5378 u64 left_offset_fixed;
5386 path = alloc_path_for_send();
5390 eb = left_path->nodes[0];
5391 slot = left_path->slots[0];
5392 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
5393 left_type = btrfs_file_extent_type(eb, ei);
5395 if (left_type != BTRFS_FILE_EXTENT_REG) {
5399 left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
5400 left_len = btrfs_file_extent_num_bytes(eb, ei);
5401 left_offset = btrfs_file_extent_offset(eb, ei);
5402 left_gen = btrfs_file_extent_generation(eb, ei);
5405 * Following comments will refer to these graphics. L is the left
5406 * extents which we are checking at the moment. 1-8 are the right
5407 * extents that we iterate.
5410 * |-1-|-2a-|-3-|-4-|-5-|-6-|
5413 * |--1--|-2b-|...(same as above)
5415 * Alternative situation. Happens on files where extents got split.
5417 * |-----------7-----------|-6-|
5419 * Alternative situation. Happens on files which got larger.
5422 * Nothing follows after 8.
5425 key.objectid = ekey->objectid;
5426 key.type = BTRFS_EXTENT_DATA_KEY;
5427 key.offset = ekey->offset;
5428 ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
5437 * Handle special case where the right side has no extents at all.
5439 eb = path->nodes[0];
5440 slot = path->slots[0];
5441 btrfs_item_key_to_cpu(eb, &found_key, slot);
5442 if (found_key.objectid != key.objectid ||
5443 found_key.type != key.type) {
5444 /* If we're a hole then just pretend nothing changed */
5445 ret = (left_disknr) ? 0 : 1;
5450 * We're now on 2a, 2b or 7.
5453 while (key.offset < ekey->offset + left_len) {
5454 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
5455 right_type = btrfs_file_extent_type(eb, ei);
5456 if (right_type != BTRFS_FILE_EXTENT_REG &&
5457 right_type != BTRFS_FILE_EXTENT_INLINE) {
5462 if (right_type == BTRFS_FILE_EXTENT_INLINE) {
5463 right_len = btrfs_file_extent_ram_bytes(eb, ei);
5464 right_len = PAGE_ALIGN(right_len);
5466 right_len = btrfs_file_extent_num_bytes(eb, ei);
5470 * Are we at extent 8? If yes, we know the extent is changed.
5471 * This may only happen on the first iteration.
5473 if (found_key.offset + right_len <= ekey->offset) {
5474 /* If we're a hole just pretend nothing changed */
5475 ret = (left_disknr) ? 0 : 1;
5480 * We just wanted to see if when we have an inline extent, what
5481 * follows it is a regular extent (wanted to check the above
5482 * condition for inline extents too). This should normally not
5483 * happen but it's possible for example when we have an inline
5484 * compressed extent representing data with a size matching
5485 * the page size (currently the same as sector size).
5487 if (right_type == BTRFS_FILE_EXTENT_INLINE) {
5492 right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
5493 right_offset = btrfs_file_extent_offset(eb, ei);
5494 right_gen = btrfs_file_extent_generation(eb, ei);
5496 left_offset_fixed = left_offset;
5497 if (key.offset < ekey->offset) {
5498 /* Fix the right offset for 2a and 7. */
5499 right_offset += ekey->offset - key.offset;
5501 /* Fix the left offset for all behind 2a and 2b */
5502 left_offset_fixed += key.offset - ekey->offset;
5506 * Check if we have the same extent.
5508 if (left_disknr != right_disknr ||
5509 left_offset_fixed != right_offset ||
5510 left_gen != right_gen) {
5516 * Go to the next extent.
5518 ret = btrfs_next_item(sctx->parent_root, path);
5522 eb = path->nodes[0];
5523 slot = path->slots[0];
5524 btrfs_item_key_to_cpu(eb, &found_key, slot);
5526 if (ret || found_key.objectid != key.objectid ||
5527 found_key.type != key.type) {
5528 key.offset += right_len;
5531 if (found_key.offset != key.offset + right_len) {
5539 * We're now behind the left extent (treat as unchanged) or at the end
5540 * of the right side (treat as changed).
5542 if (key.offset >= ekey->offset + left_len)
5549 btrfs_free_path(path);
5553 static int get_last_extent(struct send_ctx *sctx, u64 offset)
5555 struct btrfs_path *path;
5556 struct btrfs_root *root = sctx->send_root;
5557 struct btrfs_file_extent_item *fi;
5558 struct btrfs_key key;
5563 path = alloc_path_for_send();
5567 sctx->cur_inode_last_extent = 0;
5569 key.objectid = sctx->cur_ino;
5570 key.type = BTRFS_EXTENT_DATA_KEY;
5571 key.offset = offset;
5572 ret = btrfs_search_slot_for_read(root, &key, path, 0, 1);
5576 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
5577 if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY)
5580 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
5581 struct btrfs_file_extent_item);
5582 type = btrfs_file_extent_type(path->nodes[0], fi);
5583 if (type == BTRFS_FILE_EXTENT_INLINE) {
5584 u64 size = btrfs_file_extent_ram_bytes(path->nodes[0], fi);
5585 extent_end = ALIGN(key.offset + size,
5586 sctx->send_root->fs_info->sectorsize);
5588 extent_end = key.offset +
5589 btrfs_file_extent_num_bytes(path->nodes[0], fi);
5591 sctx->cur_inode_last_extent = extent_end;
5593 btrfs_free_path(path);
5597 static int range_is_hole_in_parent(struct send_ctx *sctx,
5601 struct btrfs_path *path;
5602 struct btrfs_key key;
5603 struct btrfs_root *root = sctx->parent_root;
5604 u64 search_start = start;
5607 path = alloc_path_for_send();
5611 key.objectid = sctx->cur_ino;
5612 key.type = BTRFS_EXTENT_DATA_KEY;
5613 key.offset = search_start;
5614 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5617 if (ret > 0 && path->slots[0] > 0)
5620 while (search_start < end) {
5621 struct extent_buffer *leaf = path->nodes[0];
5622 int slot = path->slots[0];
5623 struct btrfs_file_extent_item *fi;
5626 if (slot >= btrfs_header_nritems(leaf)) {
5627 ret = btrfs_next_leaf(root, path);
5635 btrfs_item_key_to_cpu(leaf, &key, slot);
5636 if (key.objectid < sctx->cur_ino ||
5637 key.type < BTRFS_EXTENT_DATA_KEY)
5639 if (key.objectid > sctx->cur_ino ||
5640 key.type > BTRFS_EXTENT_DATA_KEY ||
5644 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5645 if (btrfs_file_extent_type(leaf, fi) ==
5646 BTRFS_FILE_EXTENT_INLINE) {
5647 u64 size = btrfs_file_extent_ram_bytes(leaf, fi);
5649 extent_end = ALIGN(key.offset + size,
5650 root->fs_info->sectorsize);
5652 extent_end = key.offset +
5653 btrfs_file_extent_num_bytes(leaf, fi);
5655 if (extent_end <= start)
5657 if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) {
5658 search_start = extent_end;
5668 btrfs_free_path(path);
5672 static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
5673 struct btrfs_key *key)
5675 struct btrfs_file_extent_item *fi;
5680 if (sctx->cur_ino != key->objectid || !need_send_hole(sctx))
5683 if (sctx->cur_inode_last_extent == (u64)-1) {
5684 ret = get_last_extent(sctx, key->offset - 1);
5689 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
5690 struct btrfs_file_extent_item);
5691 type = btrfs_file_extent_type(path->nodes[0], fi);
5692 if (type == BTRFS_FILE_EXTENT_INLINE) {
5693 u64 size = btrfs_file_extent_ram_bytes(path->nodes[0], fi);
5694 extent_end = ALIGN(key->offset + size,
5695 sctx->send_root->fs_info->sectorsize);
5697 extent_end = key->offset +
5698 btrfs_file_extent_num_bytes(path->nodes[0], fi);
5701 if (path->slots[0] == 0 &&
5702 sctx->cur_inode_last_extent < key->offset) {
5704 * We might have skipped entire leafs that contained only
5705 * file extent items for our current inode. These leafs have
5706 * a generation number smaller (older) than the one in the
5707 * current leaf and the leaf our last extent came from, and
5708 * are located between these 2 leafs.
5710 ret = get_last_extent(sctx, key->offset - 1);
5715 if (sctx->cur_inode_last_extent < key->offset) {
5716 ret = range_is_hole_in_parent(sctx,
5717 sctx->cur_inode_last_extent,
5722 ret = send_hole(sctx, key->offset);
5726 sctx->cur_inode_last_extent = extent_end;
5730 static int process_extent(struct send_ctx *sctx,
5731 struct btrfs_path *path,
5732 struct btrfs_key *key)
5734 struct clone_root *found_clone = NULL;
5737 if (S_ISLNK(sctx->cur_inode_mode))
5740 if (sctx->parent_root && !sctx->cur_inode_new) {
5741 ret = is_extent_unchanged(sctx, path, key);
5749 struct btrfs_file_extent_item *ei;
5752 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
5753 struct btrfs_file_extent_item);
5754 type = btrfs_file_extent_type(path->nodes[0], ei);
5755 if (type == BTRFS_FILE_EXTENT_PREALLOC ||
5756 type == BTRFS_FILE_EXTENT_REG) {
5758 * The send spec does not have a prealloc command yet,
5759 * so just leave a hole for prealloc'ed extents until
5760 * we have enough commands queued up to justify rev'ing
5763 if (type == BTRFS_FILE_EXTENT_PREALLOC) {
5768 /* Have a hole, just skip it. */
5769 if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
5776 ret = find_extent_clone(sctx, path, key->objectid, key->offset,
5777 sctx->cur_inode_size, &found_clone);
5778 if (ret != -ENOENT && ret < 0)
5781 ret = send_write_or_clone(sctx, path, key, found_clone);
5785 ret = maybe_send_hole(sctx, path, key);
5790 static int process_all_extents(struct send_ctx *sctx)
5793 struct btrfs_root *root;
5794 struct btrfs_path *path;
5795 struct btrfs_key key;
5796 struct btrfs_key found_key;
5797 struct extent_buffer *eb;
5800 root = sctx->send_root;
5801 path = alloc_path_for_send();
5805 key.objectid = sctx->cmp_key->objectid;
5806 key.type = BTRFS_EXTENT_DATA_KEY;
5808 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5813 eb = path->nodes[0];
5814 slot = path->slots[0];
5816 if (slot >= btrfs_header_nritems(eb)) {
5817 ret = btrfs_next_leaf(root, path);
5820 } else if (ret > 0) {
5827 btrfs_item_key_to_cpu(eb, &found_key, slot);
5829 if (found_key.objectid != key.objectid ||
5830 found_key.type != key.type) {
5835 ret = process_extent(sctx, path, &found_key);
5843 btrfs_free_path(path);
5847 static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
5849 int *refs_processed)
5853 if (sctx->cur_ino == 0)
5855 if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
5856 sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
5858 if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
5861 ret = process_recorded_refs(sctx, pending_move);
5865 *refs_processed = 1;
5870 static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
5881 int need_truncate = 1;
5882 int pending_move = 0;
5883 int refs_processed = 0;
5885 if (sctx->ignore_cur_inode)
5888 ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
5894 * We have processed the refs and thus need to advance send_progress.
5895 * Now, calls to get_cur_xxx will take the updated refs of the current
5896 * inode into account.
5898 * On the other hand, if our current inode is a directory and couldn't
5899 * be moved/renamed because its parent was renamed/moved too and it has
5900 * a higher inode number, we can only move/rename our current inode
5901 * after we moved/renamed its parent. Therefore in this case operate on
5902 * the old path (pre move/rename) of our current inode, and the
5903 * move/rename will be performed later.
5905 if (refs_processed && !pending_move)
5906 sctx->send_progress = sctx->cur_ino + 1;
5908 if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
5910 if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
5913 ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
5914 &left_mode, &left_uid, &left_gid, NULL);
5918 if (!sctx->parent_root || sctx->cur_inode_new) {
5920 if (!S_ISLNK(sctx->cur_inode_mode))
5922 if (sctx->cur_inode_next_write_offset == sctx->cur_inode_size)
5927 ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
5928 &old_size, NULL, &right_mode, &right_uid,
5933 if (left_uid != right_uid || left_gid != right_gid)
5935 if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
5937 if ((old_size == sctx->cur_inode_size) ||
5938 (sctx->cur_inode_size > old_size &&
5939 sctx->cur_inode_next_write_offset == sctx->cur_inode_size))
5943 if (S_ISREG(sctx->cur_inode_mode)) {
5944 if (need_send_hole(sctx)) {
5945 if (sctx->cur_inode_last_extent == (u64)-1 ||
5946 sctx->cur_inode_last_extent <
5947 sctx->cur_inode_size) {
5948 ret = get_last_extent(sctx, (u64)-1);
5952 if (sctx->cur_inode_last_extent <
5953 sctx->cur_inode_size) {
5954 ret = send_hole(sctx, sctx->cur_inode_size);
5959 if (need_truncate) {
5960 ret = send_truncate(sctx, sctx->cur_ino,
5961 sctx->cur_inode_gen,
5962 sctx->cur_inode_size);
5969 ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5970 left_uid, left_gid);
5975 ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5982 * If other directory inodes depended on our current directory
5983 * inode's move/rename, now do their move/rename operations.
5985 if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
5986 ret = apply_children_dir_moves(sctx);
5990 * Need to send that every time, no matter if it actually
5991 * changed between the two trees as we have done changes to
5992 * the inode before. If our inode is a directory and it's
5993 * waiting to be moved/renamed, we will send its utimes when
5994 * it's moved/renamed, therefore we don't need to do it here.
5996 sctx->send_progress = sctx->cur_ino + 1;
5997 ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
6006 struct parent_paths_ctx {
6007 struct list_head *refs;
6008 struct send_ctx *sctx;
6011 static int record_parent_ref(int num, u64 dir, int index, struct fs_path *name,
6014 struct parent_paths_ctx *ppctx = ctx;
6016 return record_ref(ppctx->sctx->parent_root, dir, name, ppctx->sctx,
6021 * Issue unlink operations for all paths of the current inode found in the
6024 static int btrfs_unlink_all_paths(struct send_ctx *sctx)
6026 LIST_HEAD(deleted_refs);
6027 struct btrfs_path *path;
6028 struct btrfs_key key;
6029 struct parent_paths_ctx ctx;
6032 path = alloc_path_for_send();
6036 key.objectid = sctx->cur_ino;
6037 key.type = BTRFS_INODE_REF_KEY;
6039 ret = btrfs_search_slot(NULL, sctx->parent_root, &key, path, 0, 0);
6043 ctx.refs = &deleted_refs;
6047 struct extent_buffer *eb = path->nodes[0];
6048 int slot = path->slots[0];
6050 if (slot >= btrfs_header_nritems(eb)) {
6051 ret = btrfs_next_leaf(sctx->parent_root, path);
6059 btrfs_item_key_to_cpu(eb, &key, slot);
6060 if (key.objectid != sctx->cur_ino)
6062 if (key.type != BTRFS_INODE_REF_KEY &&
6063 key.type != BTRFS_INODE_EXTREF_KEY)
6066 ret = iterate_inode_ref(sctx->parent_root, path, &key, 1,
6067 record_parent_ref, &ctx);
6074 while (!list_empty(&deleted_refs)) {
6075 struct recorded_ref *ref;
6077 ref = list_first_entry(&deleted_refs, struct recorded_ref, list);
6078 ret = send_unlink(sctx, ref->full_path);
6081 fs_path_free(ref->full_path);
6082 list_del(&ref->list);
6087 btrfs_free_path(path);
6089 __free_recorded_refs(&deleted_refs);
6093 static int changed_inode(struct send_ctx *sctx,
6094 enum btrfs_compare_tree_result result)
6097 struct btrfs_key *key = sctx->cmp_key;
6098 struct btrfs_inode_item *left_ii = NULL;
6099 struct btrfs_inode_item *right_ii = NULL;
6103 sctx->cur_ino = key->objectid;
6104 sctx->cur_inode_new_gen = 0;
6105 sctx->cur_inode_last_extent = (u64)-1;
6106 sctx->cur_inode_next_write_offset = 0;
6107 sctx->ignore_cur_inode = false;
6110 * Set send_progress to current inode. This will tell all get_cur_xxx
6111 * functions that the current inode's refs are not updated yet. Later,
6112 * when process_recorded_refs is finished, it is set to cur_ino + 1.
6114 sctx->send_progress = sctx->cur_ino;
6116 if (result == BTRFS_COMPARE_TREE_NEW ||
6117 result == BTRFS_COMPARE_TREE_CHANGED) {
6118 left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
6119 sctx->left_path->slots[0],
6120 struct btrfs_inode_item);
6121 left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
6124 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
6125 sctx->right_path->slots[0],
6126 struct btrfs_inode_item);
6127 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
6130 if (result == BTRFS_COMPARE_TREE_CHANGED) {
6131 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
6132 sctx->right_path->slots[0],
6133 struct btrfs_inode_item);
6135 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
6139 * The cur_ino = root dir case is special here. We can't treat
6140 * the inode as deleted+reused because it would generate a
6141 * stream that tries to delete/mkdir the root dir.
6143 if (left_gen != right_gen &&
6144 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
6145 sctx->cur_inode_new_gen = 1;
6149 * Normally we do not find inodes with a link count of zero (orphans)
6150 * because the most common case is to create a snapshot and use it
6151 * for a send operation. However other less common use cases involve
6152 * using a subvolume and send it after turning it to RO mode just
6153 * after deleting all hard links of a file while holding an open
6154 * file descriptor against it or turning a RO snapshot into RW mode,
6155 * keep an open file descriptor against a file, delete it and then
6156 * turn the snapshot back to RO mode before using it for a send
6157 * operation. So if we find such cases, ignore the inode and all its
6158 * items completely if it's a new inode, or if it's a changed inode
6159 * make sure all its previous paths (from the parent snapshot) are all
6160 * unlinked and all other the inode items are ignored.
6162 if (result == BTRFS_COMPARE_TREE_NEW ||
6163 result == BTRFS_COMPARE_TREE_CHANGED) {
6166 nlinks = btrfs_inode_nlink(sctx->left_path->nodes[0], left_ii);
6168 sctx->ignore_cur_inode = true;
6169 if (result == BTRFS_COMPARE_TREE_CHANGED)
6170 ret = btrfs_unlink_all_paths(sctx);
6175 if (result == BTRFS_COMPARE_TREE_NEW) {
6176 sctx->cur_inode_gen = left_gen;
6177 sctx->cur_inode_new = 1;
6178 sctx->cur_inode_deleted = 0;
6179 sctx->cur_inode_size = btrfs_inode_size(
6180 sctx->left_path->nodes[0], left_ii);
6181 sctx->cur_inode_mode = btrfs_inode_mode(
6182 sctx->left_path->nodes[0], left_ii);
6183 sctx->cur_inode_rdev = btrfs_inode_rdev(
6184 sctx->left_path->nodes[0], left_ii);
6185 if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
6186 ret = send_create_inode_if_needed(sctx);
6187 } else if (result == BTRFS_COMPARE_TREE_DELETED) {
6188 sctx->cur_inode_gen = right_gen;
6189 sctx->cur_inode_new = 0;
6190 sctx->cur_inode_deleted = 1;
6191 sctx->cur_inode_size = btrfs_inode_size(
6192 sctx->right_path->nodes[0], right_ii);
6193 sctx->cur_inode_mode = btrfs_inode_mode(
6194 sctx->right_path->nodes[0], right_ii);
6195 } else if (result == BTRFS_COMPARE_TREE_CHANGED) {
6197 * We need to do some special handling in case the inode was
6198 * reported as changed with a changed generation number. This
6199 * means that the original inode was deleted and new inode
6200 * reused the same inum. So we have to treat the old inode as
6201 * deleted and the new one as new.
6203 if (sctx->cur_inode_new_gen) {
6205 * First, process the inode as if it was deleted.
6207 sctx->cur_inode_gen = right_gen;
6208 sctx->cur_inode_new = 0;
6209 sctx->cur_inode_deleted = 1;
6210 sctx->cur_inode_size = btrfs_inode_size(
6211 sctx->right_path->nodes[0], right_ii);
6212 sctx->cur_inode_mode = btrfs_inode_mode(
6213 sctx->right_path->nodes[0], right_ii);
6214 ret = process_all_refs(sctx,
6215 BTRFS_COMPARE_TREE_DELETED);
6220 * Now process the inode as if it was new.
6222 sctx->cur_inode_gen = left_gen;
6223 sctx->cur_inode_new = 1;
6224 sctx->cur_inode_deleted = 0;
6225 sctx->cur_inode_size = btrfs_inode_size(
6226 sctx->left_path->nodes[0], left_ii);
6227 sctx->cur_inode_mode = btrfs_inode_mode(
6228 sctx->left_path->nodes[0], left_ii);
6229 sctx->cur_inode_rdev = btrfs_inode_rdev(
6230 sctx->left_path->nodes[0], left_ii);
6231 ret = send_create_inode_if_needed(sctx);
6235 ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
6239 * Advance send_progress now as we did not get into
6240 * process_recorded_refs_if_needed in the new_gen case.
6242 sctx->send_progress = sctx->cur_ino + 1;
6245 * Now process all extents and xattrs of the inode as if
6246 * they were all new.
6248 ret = process_all_extents(sctx);
6251 ret = process_all_new_xattrs(sctx);
6255 sctx->cur_inode_gen = left_gen;
6256 sctx->cur_inode_new = 0;
6257 sctx->cur_inode_new_gen = 0;
6258 sctx->cur_inode_deleted = 0;
6259 sctx->cur_inode_size = btrfs_inode_size(
6260 sctx->left_path->nodes[0], left_ii);
6261 sctx->cur_inode_mode = btrfs_inode_mode(
6262 sctx->left_path->nodes[0], left_ii);
6271 * We have to process new refs before deleted refs, but compare_trees gives us
6272 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
6273 * first and later process them in process_recorded_refs.
6274 * For the cur_inode_new_gen case, we skip recording completely because
6275 * changed_inode did already initiate processing of refs. The reason for this is
6276 * that in this case, compare_tree actually compares the refs of 2 different
6277 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
6278 * refs of the right tree as deleted and all refs of the left tree as new.
6280 static int changed_ref(struct send_ctx *sctx,
6281 enum btrfs_compare_tree_result result)
6285 if (sctx->cur_ino != sctx->cmp_key->objectid) {
6286 inconsistent_snapshot_error(sctx, result, "reference");
6290 if (!sctx->cur_inode_new_gen &&
6291 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
6292 if (result == BTRFS_COMPARE_TREE_NEW)
6293 ret = record_new_ref(sctx);
6294 else if (result == BTRFS_COMPARE_TREE_DELETED)
6295 ret = record_deleted_ref(sctx);
6296 else if (result == BTRFS_COMPARE_TREE_CHANGED)
6297 ret = record_changed_ref(sctx);
6304 * Process new/deleted/changed xattrs. We skip processing in the
6305 * cur_inode_new_gen case because changed_inode did already initiate processing
6306 * of xattrs. The reason is the same as in changed_ref
6308 static int changed_xattr(struct send_ctx *sctx,
6309 enum btrfs_compare_tree_result result)
6313 if (sctx->cur_ino != sctx->cmp_key->objectid) {
6314 inconsistent_snapshot_error(sctx, result, "xattr");
6318 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
6319 if (result == BTRFS_COMPARE_TREE_NEW)
6320 ret = process_new_xattr(sctx);
6321 else if (result == BTRFS_COMPARE_TREE_DELETED)
6322 ret = process_deleted_xattr(sctx);
6323 else if (result == BTRFS_COMPARE_TREE_CHANGED)
6324 ret = process_changed_xattr(sctx);
6331 * Process new/deleted/changed extents. We skip processing in the
6332 * cur_inode_new_gen case because changed_inode did already initiate processing
6333 * of extents. The reason is the same as in changed_ref
6335 static int changed_extent(struct send_ctx *sctx,
6336 enum btrfs_compare_tree_result result)
6341 * We have found an extent item that changed without the inode item
6342 * having changed. This can happen either after relocation (where the
6343 * disk_bytenr of an extent item is replaced at
6344 * relocation.c:replace_file_extents()) or after deduplication into a
6345 * file in both the parent and send snapshots (where an extent item can
6346 * get modified or replaced with a new one). Note that deduplication
6347 * updates the inode item, but it only changes the iversion (sequence
6348 * field in the inode item) of the inode, so if a file is deduplicated
6349 * the same amount of times in both the parent and send snapshots, its
6350 * iversion becames the same in both snapshots, whence the inode item is
6351 * the same on both snapshots.
6353 if (sctx->cur_ino != sctx->cmp_key->objectid)
6356 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
6357 if (result != BTRFS_COMPARE_TREE_DELETED)
6358 ret = process_extent(sctx, sctx->left_path,
6365 static int dir_changed(struct send_ctx *sctx, u64 dir)
6367 u64 orig_gen, new_gen;
6370 ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
6375 ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
6380 return (orig_gen != new_gen) ? 1 : 0;
6383 static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path,
6384 struct btrfs_key *key)
6386 struct btrfs_inode_extref *extref;
6387 struct extent_buffer *leaf;
6388 u64 dirid = 0, last_dirid = 0;
6395 /* Easy case, just check this one dirid */
6396 if (key->type == BTRFS_INODE_REF_KEY) {
6397 dirid = key->offset;
6399 ret = dir_changed(sctx, dirid);
6403 leaf = path->nodes[0];
6404 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
6405 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
6406 while (cur_offset < item_size) {
6407 extref = (struct btrfs_inode_extref *)(ptr +
6409 dirid = btrfs_inode_extref_parent(leaf, extref);
6410 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
6411 cur_offset += ref_name_len + sizeof(*extref);
6412 if (dirid == last_dirid)
6414 ret = dir_changed(sctx, dirid);
6424 * Updates compare related fields in sctx and simply forwards to the actual
6425 * changed_xxx functions.
6427 static int changed_cb(struct btrfs_path *left_path,
6428 struct btrfs_path *right_path,
6429 struct btrfs_key *key,
6430 enum btrfs_compare_tree_result result,
6434 struct send_ctx *sctx = ctx;
6436 if (result == BTRFS_COMPARE_TREE_SAME) {
6437 if (key->type == BTRFS_INODE_REF_KEY ||
6438 key->type == BTRFS_INODE_EXTREF_KEY) {
6439 ret = compare_refs(sctx, left_path, key);
6444 } else if (key->type == BTRFS_EXTENT_DATA_KEY) {
6445 return maybe_send_hole(sctx, left_path, key);
6449 result = BTRFS_COMPARE_TREE_CHANGED;
6453 sctx->left_path = left_path;
6454 sctx->right_path = right_path;
6455 sctx->cmp_key = key;
6457 ret = finish_inode_if_needed(sctx, 0);
6461 /* Ignore non-FS objects */
6462 if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
6463 key->objectid == BTRFS_FREE_SPACE_OBJECTID)
6466 if (key->type == BTRFS_INODE_ITEM_KEY) {
6467 ret = changed_inode(sctx, result);
6468 } else if (!sctx->ignore_cur_inode) {
6469 if (key->type == BTRFS_INODE_REF_KEY ||
6470 key->type == BTRFS_INODE_EXTREF_KEY)
6471 ret = changed_ref(sctx, result);
6472 else if (key->type == BTRFS_XATTR_ITEM_KEY)
6473 ret = changed_xattr(sctx, result);
6474 else if (key->type == BTRFS_EXTENT_DATA_KEY)
6475 ret = changed_extent(sctx, result);
6482 static int full_send_tree(struct send_ctx *sctx)
6485 struct btrfs_root *send_root = sctx->send_root;
6486 struct btrfs_key key;
6487 struct btrfs_path *path;
6488 struct extent_buffer *eb;
6491 path = alloc_path_for_send();
6495 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
6496 key.type = BTRFS_INODE_ITEM_KEY;
6499 ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
6506 eb = path->nodes[0];
6507 slot = path->slots[0];
6508 btrfs_item_key_to_cpu(eb, &key, slot);
6510 ret = changed_cb(path, NULL, &key,
6511 BTRFS_COMPARE_TREE_NEW, sctx);
6515 ret = btrfs_next_item(send_root, path);
6525 ret = finish_inode_if_needed(sctx, 1);
6528 btrfs_free_path(path);
6532 static int tree_move_down(struct btrfs_path *path, int *level)
6534 struct extent_buffer *eb;
6536 BUG_ON(*level == 0);
6537 eb = btrfs_read_node_slot(path->nodes[*level], path->slots[*level]);
6541 path->nodes[*level - 1] = eb;
6542 path->slots[*level - 1] = 0;
6547 static int tree_move_next_or_upnext(struct btrfs_path *path,
6548 int *level, int root_level)
6552 nritems = btrfs_header_nritems(path->nodes[*level]);
6554 path->slots[*level]++;
6556 while (path->slots[*level] >= nritems) {
6557 if (*level == root_level)
6561 path->slots[*level] = 0;
6562 free_extent_buffer(path->nodes[*level]);
6563 path->nodes[*level] = NULL;
6565 path->slots[*level]++;
6567 nritems = btrfs_header_nritems(path->nodes[*level]);
6574 * Returns 1 if it had to move up and next. 0 is returned if it moved only next
6577 static int tree_advance(struct btrfs_path *path,
6578 int *level, int root_level,
6580 struct btrfs_key *key)
6584 if (*level == 0 || !allow_down) {
6585 ret = tree_move_next_or_upnext(path, level, root_level);
6587 ret = tree_move_down(path, level);
6591 btrfs_item_key_to_cpu(path->nodes[*level], key,
6592 path->slots[*level]);
6594 btrfs_node_key_to_cpu(path->nodes[*level], key,
6595 path->slots[*level]);
6600 static int tree_compare_item(struct btrfs_path *left_path,
6601 struct btrfs_path *right_path,
6606 unsigned long off1, off2;
6608 len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]);
6609 len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]);
6613 off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]);
6614 off2 = btrfs_item_ptr_offset(right_path->nodes[0],
6615 right_path->slots[0]);
6617 read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1);
6619 cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1);
6626 * This function compares two trees and calls the provided callback for
6627 * every changed/new/deleted item it finds.
6628 * If shared tree blocks are encountered, whole subtrees are skipped, making
6629 * the compare pretty fast on snapshotted subvolumes.
6631 * This currently works on commit roots only. As commit roots are read only,
6632 * we don't do any locking. The commit roots are protected with transactions.
6633 * Transactions are ended and rejoined when a commit is tried in between.
6635 * This function checks for modifications done to the trees while comparing.
6636 * If it detects a change, it aborts immediately.
6638 static int btrfs_compare_trees(struct btrfs_root *left_root,
6639 struct btrfs_root *right_root,
6640 btrfs_changed_cb_t changed_cb, void *ctx)
6642 struct btrfs_fs_info *fs_info = left_root->fs_info;
6645 struct btrfs_path *left_path = NULL;
6646 struct btrfs_path *right_path = NULL;
6647 struct btrfs_key left_key;
6648 struct btrfs_key right_key;
6649 char *tmp_buf = NULL;
6650 int left_root_level;
6651 int right_root_level;
6654 int left_end_reached;
6655 int right_end_reached;
6663 left_path = btrfs_alloc_path();
6668 right_path = btrfs_alloc_path();
6674 tmp_buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
6680 left_path->search_commit_root = 1;
6681 left_path->skip_locking = 1;
6682 right_path->search_commit_root = 1;
6683 right_path->skip_locking = 1;
6686 * Strategy: Go to the first items of both trees. Then do
6688 * If both trees are at level 0
6689 * Compare keys of current items
6690 * If left < right treat left item as new, advance left tree
6692 * If left > right treat right item as deleted, advance right tree
6694 * If left == right do deep compare of items, treat as changed if
6695 * needed, advance both trees and repeat
6696 * If both trees are at the same level but not at level 0
6697 * Compare keys of current nodes/leafs
6698 * If left < right advance left tree and repeat
6699 * If left > right advance right tree and repeat
6700 * If left == right compare blockptrs of the next nodes/leafs
6701 * If they match advance both trees but stay at the same level
6703 * If they don't match advance both trees while allowing to go
6705 * If tree levels are different
6706 * Advance the tree that needs it and repeat
6708 * Advancing a tree means:
6709 * If we are at level 0, try to go to the next slot. If that's not
6710 * possible, go one level up and repeat. Stop when we found a level
6711 * where we could go to the next slot. We may at this point be on a
6714 * If we are not at level 0 and not on shared tree blocks, go one
6717 * If we are not at level 0 and on shared tree blocks, go one slot to
6718 * the right if possible or go up and right.
6721 down_read(&fs_info->commit_root_sem);
6722 left_level = btrfs_header_level(left_root->commit_root);
6723 left_root_level = left_level;
6724 left_path->nodes[left_level] =
6725 btrfs_clone_extent_buffer(left_root->commit_root);
6726 if (!left_path->nodes[left_level]) {
6727 up_read(&fs_info->commit_root_sem);
6732 right_level = btrfs_header_level(right_root->commit_root);
6733 right_root_level = right_level;
6734 right_path->nodes[right_level] =
6735 btrfs_clone_extent_buffer(right_root->commit_root);
6736 if (!right_path->nodes[right_level]) {
6737 up_read(&fs_info->commit_root_sem);
6741 up_read(&fs_info->commit_root_sem);
6743 if (left_level == 0)
6744 btrfs_item_key_to_cpu(left_path->nodes[left_level],
6745 &left_key, left_path->slots[left_level]);
6747 btrfs_node_key_to_cpu(left_path->nodes[left_level],
6748 &left_key, left_path->slots[left_level]);
6749 if (right_level == 0)
6750 btrfs_item_key_to_cpu(right_path->nodes[right_level],
6751 &right_key, right_path->slots[right_level]);
6753 btrfs_node_key_to_cpu(right_path->nodes[right_level],
6754 &right_key, right_path->slots[right_level]);
6756 left_end_reached = right_end_reached = 0;
6757 advance_left = advance_right = 0;
6761 if (advance_left && !left_end_reached) {
6762 ret = tree_advance(left_path, &left_level,
6764 advance_left != ADVANCE_ONLY_NEXT,
6767 left_end_reached = ADVANCE;
6772 if (advance_right && !right_end_reached) {
6773 ret = tree_advance(right_path, &right_level,
6775 advance_right != ADVANCE_ONLY_NEXT,
6778 right_end_reached = ADVANCE;
6784 if (left_end_reached && right_end_reached) {
6787 } else if (left_end_reached) {
6788 if (right_level == 0) {
6789 ret = changed_cb(left_path, right_path,
6791 BTRFS_COMPARE_TREE_DELETED,
6796 advance_right = ADVANCE;
6798 } else if (right_end_reached) {
6799 if (left_level == 0) {
6800 ret = changed_cb(left_path, right_path,
6802 BTRFS_COMPARE_TREE_NEW,
6807 advance_left = ADVANCE;
6811 if (left_level == 0 && right_level == 0) {
6812 cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
6814 ret = changed_cb(left_path, right_path,
6816 BTRFS_COMPARE_TREE_NEW,
6820 advance_left = ADVANCE;
6821 } else if (cmp > 0) {
6822 ret = changed_cb(left_path, right_path,
6824 BTRFS_COMPARE_TREE_DELETED,
6828 advance_right = ADVANCE;
6830 enum btrfs_compare_tree_result result;
6832 WARN_ON(!extent_buffer_uptodate(left_path->nodes[0]));
6833 ret = tree_compare_item(left_path, right_path,
6836 result = BTRFS_COMPARE_TREE_CHANGED;
6838 result = BTRFS_COMPARE_TREE_SAME;
6839 ret = changed_cb(left_path, right_path,
6840 &left_key, result, ctx);
6843 advance_left = ADVANCE;
6844 advance_right = ADVANCE;
6846 } else if (left_level == right_level) {
6847 cmp = btrfs_comp_cpu_keys(&left_key, &right_key);
6849 advance_left = ADVANCE;
6850 } else if (cmp > 0) {
6851 advance_right = ADVANCE;
6853 left_blockptr = btrfs_node_blockptr(
6854 left_path->nodes[left_level],
6855 left_path->slots[left_level]);
6856 right_blockptr = btrfs_node_blockptr(
6857 right_path->nodes[right_level],
6858 right_path->slots[right_level]);
6859 left_gen = btrfs_node_ptr_generation(
6860 left_path->nodes[left_level],
6861 left_path->slots[left_level]);
6862 right_gen = btrfs_node_ptr_generation(
6863 right_path->nodes[right_level],
6864 right_path->slots[right_level]);
6865 if (left_blockptr == right_blockptr &&
6866 left_gen == right_gen) {
6868 * As we're on a shared block, don't
6869 * allow to go deeper.
6871 advance_left = ADVANCE_ONLY_NEXT;
6872 advance_right = ADVANCE_ONLY_NEXT;
6874 advance_left = ADVANCE;
6875 advance_right = ADVANCE;
6878 } else if (left_level < right_level) {
6879 advance_right = ADVANCE;
6881 advance_left = ADVANCE;
6886 btrfs_free_path(left_path);
6887 btrfs_free_path(right_path);
6892 static int send_subvol(struct send_ctx *sctx)
6896 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
6897 ret = send_header(sctx);
6902 ret = send_subvol_begin(sctx);
6906 if (sctx->parent_root) {
6907 ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
6911 ret = finish_inode_if_needed(sctx, 1);
6915 ret = full_send_tree(sctx);
6921 free_recorded_refs(sctx);
6926 * If orphan cleanup did remove any orphans from a root, it means the tree
6927 * was modified and therefore the commit root is not the same as the current
6928 * root anymore. This is a problem, because send uses the commit root and
6929 * therefore can see inode items that don't exist in the current root anymore,
6930 * and for example make calls to btrfs_iget, which will do tree lookups based
6931 * on the current root and not on the commit root. Those lookups will fail,
6932 * returning a -ESTALE error, and making send fail with that error. So make
6933 * sure a send does not see any orphans we have just removed, and that it will
6934 * see the same inodes regardless of whether a transaction commit happened
6935 * before it started (meaning that the commit root will be the same as the
6936 * current root) or not.
6938 static int ensure_commit_roots_uptodate(struct send_ctx *sctx)
6941 struct btrfs_trans_handle *trans = NULL;
6944 if (sctx->parent_root &&
6945 sctx->parent_root->node != sctx->parent_root->commit_root)
6948 for (i = 0; i < sctx->clone_roots_cnt; i++)
6949 if (sctx->clone_roots[i].root->node !=
6950 sctx->clone_roots[i].root->commit_root)
6954 return btrfs_end_transaction(trans);
6959 /* Use any root, all fs roots will get their commit roots updated. */
6961 trans = btrfs_join_transaction(sctx->send_root);
6963 return PTR_ERR(trans);
6967 return btrfs_commit_transaction(trans);
6971 * Make sure any existing dellaloc is flushed for any root used by a send
6972 * operation so that we do not miss any data and we do not race with writeback
6973 * finishing and changing a tree while send is using the tree. This could
6974 * happen if a subvolume is in RW mode, has delalloc, is turned to RO mode and
6975 * a send operation then uses the subvolume.
6976 * After flushing delalloc ensure_commit_roots_uptodate() must be called.
6978 static int flush_delalloc_roots(struct send_ctx *sctx)
6980 struct btrfs_root *root = sctx->parent_root;
6985 ret = btrfs_start_delalloc_snapshot(root);
6988 btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
6991 for (i = 0; i < sctx->clone_roots_cnt; i++) {
6992 root = sctx->clone_roots[i].root;
6993 ret = btrfs_start_delalloc_snapshot(root);
6996 btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
7002 static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
7004 spin_lock(&root->root_item_lock);
7005 root->send_in_progress--;
7007 * Not much left to do, we don't know why it's unbalanced and
7008 * can't blindly reset it to 0.
7010 if (root->send_in_progress < 0)
7011 btrfs_err(root->fs_info,
7012 "send_in_progress unbalanced %d root %llu",
7013 root->send_in_progress, root->root_key.objectid);
7014 spin_unlock(&root->root_item_lock);
7017 static void dedupe_in_progress_warn(const struct btrfs_root *root)
7019 btrfs_warn_rl(root->fs_info,
7020 "cannot use root %llu for send while deduplications on it are in progress (%d in progress)",
7021 root->root_key.objectid, root->dedupe_in_progress);
7024 long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg)
7027 struct btrfs_root *send_root = BTRFS_I(file_inode(mnt_file))->root;
7028 struct btrfs_fs_info *fs_info = send_root->fs_info;
7029 struct btrfs_root *clone_root;
7030 struct btrfs_key key;
7031 struct send_ctx *sctx = NULL;
7033 u64 *clone_sources_tmp = NULL;
7034 int clone_sources_to_rollback = 0;
7035 unsigned alloc_size;
7036 int sort_clone_roots = 0;
7039 if (!capable(CAP_SYS_ADMIN))
7043 * The subvolume must remain read-only during send, protect against
7044 * making it RW. This also protects against deletion.
7046 spin_lock(&send_root->root_item_lock);
7047 if (btrfs_root_readonly(send_root) && send_root->dedupe_in_progress) {
7048 dedupe_in_progress_warn(send_root);
7049 spin_unlock(&send_root->root_item_lock);
7052 send_root->send_in_progress++;
7053 spin_unlock(&send_root->root_item_lock);
7056 * This is done when we lookup the root, it should already be complete
7057 * by the time we get here.
7059 WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE);
7062 * Userspace tools do the checks and warn the user if it's
7065 if (!btrfs_root_readonly(send_root)) {
7071 * Check that we don't overflow at later allocations, we request
7072 * clone_sources_count + 1 items, and compare to unsigned long inside
7075 if (arg->clone_sources_count >
7076 ULONG_MAX / sizeof(struct clone_root) - 1) {
7081 if (!access_ok(arg->clone_sources,
7082 sizeof(*arg->clone_sources) *
7083 arg->clone_sources_count)) {
7088 if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
7093 sctx = kzalloc(sizeof(struct send_ctx), GFP_KERNEL);
7099 INIT_LIST_HEAD(&sctx->new_refs);
7100 INIT_LIST_HEAD(&sctx->deleted_refs);
7101 INIT_RADIX_TREE(&sctx->name_cache, GFP_KERNEL);
7102 INIT_LIST_HEAD(&sctx->name_cache_list);
7104 sctx->flags = arg->flags;
7106 sctx->send_filp = fget(arg->send_fd);
7107 if (!sctx->send_filp) {
7112 sctx->send_root = send_root;
7114 * Unlikely but possible, if the subvolume is marked for deletion but
7115 * is slow to remove the directory entry, send can still be started
7117 if (btrfs_root_dead(sctx->send_root)) {
7122 sctx->clone_roots_cnt = arg->clone_sources_count;
7124 sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
7125 sctx->send_buf = kvmalloc(sctx->send_max_size, GFP_KERNEL);
7126 if (!sctx->send_buf) {
7131 sctx->read_buf = kvmalloc(BTRFS_SEND_READ_SIZE, GFP_KERNEL);
7132 if (!sctx->read_buf) {
7137 sctx->pending_dir_moves = RB_ROOT;
7138 sctx->waiting_dir_moves = RB_ROOT;
7139 sctx->orphan_dirs = RB_ROOT;
7141 alloc_size = sizeof(struct clone_root) * (arg->clone_sources_count + 1);
7143 sctx->clone_roots = kzalloc(alloc_size, GFP_KERNEL);
7144 if (!sctx->clone_roots) {
7149 alloc_size = arg->clone_sources_count * sizeof(*arg->clone_sources);
7151 if (arg->clone_sources_count) {
7152 clone_sources_tmp = kvmalloc(alloc_size, GFP_KERNEL);
7153 if (!clone_sources_tmp) {
7158 ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
7165 for (i = 0; i < arg->clone_sources_count; i++) {
7166 key.objectid = clone_sources_tmp[i];
7167 key.type = BTRFS_ROOT_ITEM_KEY;
7168 key.offset = (u64)-1;
7170 index = srcu_read_lock(&fs_info->subvol_srcu);
7172 clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
7173 if (IS_ERR(clone_root)) {
7174 srcu_read_unlock(&fs_info->subvol_srcu, index);
7175 ret = PTR_ERR(clone_root);
7178 spin_lock(&clone_root->root_item_lock);
7179 if (!btrfs_root_readonly(clone_root) ||
7180 btrfs_root_dead(clone_root)) {
7181 spin_unlock(&clone_root->root_item_lock);
7182 srcu_read_unlock(&fs_info->subvol_srcu, index);
7186 if (clone_root->dedupe_in_progress) {
7187 dedupe_in_progress_warn(clone_root);
7188 spin_unlock(&clone_root->root_item_lock);
7189 srcu_read_unlock(&fs_info->subvol_srcu, index);
7193 clone_root->send_in_progress++;
7194 spin_unlock(&clone_root->root_item_lock);
7195 srcu_read_unlock(&fs_info->subvol_srcu, index);
7197 sctx->clone_roots[i].root = clone_root;
7198 clone_sources_to_rollback = i + 1;
7200 kvfree(clone_sources_tmp);
7201 clone_sources_tmp = NULL;
7204 if (arg->parent_root) {
7205 key.objectid = arg->parent_root;
7206 key.type = BTRFS_ROOT_ITEM_KEY;
7207 key.offset = (u64)-1;
7209 index = srcu_read_lock(&fs_info->subvol_srcu);
7211 sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
7212 if (IS_ERR(sctx->parent_root)) {
7213 srcu_read_unlock(&fs_info->subvol_srcu, index);
7214 ret = PTR_ERR(sctx->parent_root);
7218 spin_lock(&sctx->parent_root->root_item_lock);
7219 sctx->parent_root->send_in_progress++;
7220 if (!btrfs_root_readonly(sctx->parent_root) ||
7221 btrfs_root_dead(sctx->parent_root)) {
7222 spin_unlock(&sctx->parent_root->root_item_lock);
7223 srcu_read_unlock(&fs_info->subvol_srcu, index);
7227 if (sctx->parent_root->dedupe_in_progress) {
7228 dedupe_in_progress_warn(sctx->parent_root);
7229 spin_unlock(&sctx->parent_root->root_item_lock);
7230 srcu_read_unlock(&fs_info->subvol_srcu, index);
7234 spin_unlock(&sctx->parent_root->root_item_lock);
7236 srcu_read_unlock(&fs_info->subvol_srcu, index);
7240 * Clones from send_root are allowed, but only if the clone source
7241 * is behind the current send position. This is checked while searching
7242 * for possible clone sources.
7244 sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;
7246 /* We do a bsearch later */
7247 sort(sctx->clone_roots, sctx->clone_roots_cnt,
7248 sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
7250 sort_clone_roots = 1;
7252 ret = flush_delalloc_roots(sctx);
7256 ret = ensure_commit_roots_uptodate(sctx);
7260 mutex_lock(&fs_info->balance_mutex);
7261 if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
7262 mutex_unlock(&fs_info->balance_mutex);
7263 btrfs_warn_rl(fs_info,
7264 "cannot run send because a balance operation is in progress");
7268 fs_info->send_in_progress++;
7269 mutex_unlock(&fs_info->balance_mutex);
7271 current->journal_info = BTRFS_SEND_TRANS_STUB;
7272 ret = send_subvol(sctx);
7273 current->journal_info = NULL;
7274 mutex_lock(&fs_info->balance_mutex);
7275 fs_info->send_in_progress--;
7276 mutex_unlock(&fs_info->balance_mutex);
7280 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) {
7281 ret = begin_cmd(sctx, BTRFS_SEND_C_END);
7284 ret = send_cmd(sctx);
7290 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
7291 while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
7293 struct pending_dir_move *pm;
7295 n = rb_first(&sctx->pending_dir_moves);
7296 pm = rb_entry(n, struct pending_dir_move, node);
7297 while (!list_empty(&pm->list)) {
7298 struct pending_dir_move *pm2;
7300 pm2 = list_first_entry(&pm->list,
7301 struct pending_dir_move, list);
7302 free_pending_move(sctx, pm2);
7304 free_pending_move(sctx, pm);
7307 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
7308 while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
7310 struct waiting_dir_move *dm;
7312 n = rb_first(&sctx->waiting_dir_moves);
7313 dm = rb_entry(n, struct waiting_dir_move, node);
7314 rb_erase(&dm->node, &sctx->waiting_dir_moves);
7318 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->orphan_dirs));
7319 while (sctx && !RB_EMPTY_ROOT(&sctx->orphan_dirs)) {
7321 struct orphan_dir_info *odi;
7323 n = rb_first(&sctx->orphan_dirs);
7324 odi = rb_entry(n, struct orphan_dir_info, node);
7325 free_orphan_dir_info(sctx, odi);
7328 if (sort_clone_roots) {
7329 for (i = 0; i < sctx->clone_roots_cnt; i++)
7330 btrfs_root_dec_send_in_progress(
7331 sctx->clone_roots[i].root);
7333 for (i = 0; sctx && i < clone_sources_to_rollback; i++)
7334 btrfs_root_dec_send_in_progress(
7335 sctx->clone_roots[i].root);
7337 btrfs_root_dec_send_in_progress(send_root);
7339 if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
7340 btrfs_root_dec_send_in_progress(sctx->parent_root);
7342 kvfree(clone_sources_tmp);
7345 if (sctx->send_filp)
7346 fput(sctx->send_filp);
7348 kvfree(sctx->clone_roots);
7349 kvfree(sctx->send_buf);
7350 kvfree(sctx->read_buf);
7352 name_cache_free(sctx);