2 * Copyright (C) 2012 Alexander Block. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/bsearch.h>
21 #include <linux/file.h>
22 #include <linux/sort.h>
23 #include <linux/mount.h>
24 #include <linux/xattr.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/radix-tree.h>
27 #include <linux/vmalloc.h>
28 #include <linux/string.h>
35 #include "btrfs_inode.h"
36 #include "transaction.h"
38 static int g_verbose = 0;
40 #define verbose_printk(...) if (g_verbose) printk(__VA_ARGS__)
43 * A fs_path is a helper to dynamically build path names with unknown size.
44 * It reallocates the internal buffer on demand.
45 * It allows fast adding of path elements on the right side (normal path) and
46 * fast adding to the left side (reversed path). A reversed path can also be
47 * unreversed if needed.
58 unsigned int reversed:1;
59 unsigned int virtual_mem:1;
65 #define FS_PATH_INLINE_SIZE \
66 (sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
69 /* reused for each extent */
71 struct btrfs_root *root;
78 #define SEND_CTX_MAX_NAME_CACHE_SIZE 128
79 #define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
82 struct file *send_filp;
88 u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
89 u64 flags; /* 'flags' member of btrfs_ioctl_send_args is u64 */
91 struct btrfs_root *send_root;
92 struct btrfs_root *parent_root;
93 struct clone_root *clone_roots;
96 /* current state of the compare_tree call */
97 struct btrfs_path *left_path;
98 struct btrfs_path *right_path;
99 struct btrfs_key *cmp_key;
102 * infos of the currently processed inode. In case of deleted inodes,
103 * these are the values from the deleted inode.
108 int cur_inode_new_gen;
109 int cur_inode_deleted;
112 u64 cur_inode_last_extent;
116 struct list_head new_refs;
117 struct list_head deleted_refs;
119 struct radix_tree_root name_cache;
120 struct list_head name_cache_list;
126 * We process inodes by their increasing order, so if before an
127 * incremental send we reverse the parent/child relationship of
128 * directories such that a directory with a lower inode number was
129 * the parent of a directory with a higher inode number, and the one
130 * becoming the new parent got renamed too, we can't rename/move the
131 * directory with lower inode number when we finish processing it - we
132 * must process the directory with higher inode number first, then
133 * rename/move it and then rename/move the directory with lower inode
134 * number. Example follows.
136 * Tree state when the first send was performed:
148 * Tree state when the second (incremental) send is performed:
157 * The sequence of steps that lead to the second state was:
159 * mv /a/b/c/d /a/b/c2/d2
160 * mv /a/b/c /a/b/c2/d2/cc
162 * "c" has lower inode number, but we can't move it (2nd mv operation)
163 * before we move "d", which has higher inode number.
165 * So we just memorize which move/rename operations must be performed
166 * later when their respective parent is processed and moved/renamed.
169 /* Indexed by parent directory inode number. */
170 struct rb_root pending_dir_moves;
173 * Reverse index, indexed by the inode number of a directory that
174 * is waiting for the move/rename of its immediate parent before its
175 * own move/rename can be performed.
177 struct rb_root waiting_dir_moves;
180 struct pending_dir_move {
182 struct list_head list;
186 struct list_head update_refs;
189 struct waiting_dir_move {
194 struct name_cache_entry {
195 struct list_head list;
197 * radix_tree has only 32bit entries but we need to handle 64bit inums.
198 * We use the lower 32bit of the 64bit inum to store it in the tree. If
199 * more then one inum would fall into the same entry, we use radix_list
200 * to store the additional entries. radix_list is also used to store
201 * entries where two entries have the same inum but different
204 struct list_head radix_list;
210 int need_later_update;
215 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);
217 static int need_send_hole(struct send_ctx *sctx)
219 return (sctx->parent_root && !sctx->cur_inode_new &&
220 !sctx->cur_inode_new_gen && !sctx->cur_inode_deleted &&
221 S_ISREG(sctx->cur_inode_mode));
224 static void fs_path_reset(struct fs_path *p)
227 p->start = p->buf + p->buf_len - 1;
237 static struct fs_path *fs_path_alloc(void)
241 p = kmalloc(sizeof(*p), GFP_NOFS);
246 p->buf = p->inline_buf;
247 p->buf_len = FS_PATH_INLINE_SIZE;
252 static struct fs_path *fs_path_alloc_reversed(void)
264 static void fs_path_free(struct fs_path *p)
268 if (p->buf != p->inline_buf) {
277 static int fs_path_len(struct fs_path *p)
279 return p->end - p->start;
282 static int fs_path_ensure_buf(struct fs_path *p, int len)
290 if (p->buf_len >= len)
293 path_len = p->end - p->start;
294 old_buf_len = p->buf_len;
295 len = PAGE_ALIGN(len);
297 if (p->buf == p->inline_buf) {
298 tmp_buf = kmalloc(len, GFP_NOFS | __GFP_NOWARN);
300 tmp_buf = vmalloc(len);
305 memcpy(tmp_buf, p->buf, p->buf_len);
309 if (p->virtual_mem) {
310 tmp_buf = vmalloc(len);
313 memcpy(tmp_buf, p->buf, p->buf_len);
316 tmp_buf = krealloc(p->buf, len, GFP_NOFS);
318 tmp_buf = vmalloc(len);
321 memcpy(tmp_buf, p->buf, p->buf_len);
330 tmp_buf = p->buf + old_buf_len - path_len - 1;
331 p->end = p->buf + p->buf_len - 1;
332 p->start = p->end - path_len;
333 memmove(p->start, tmp_buf, path_len + 1);
336 p->end = p->start + path_len;
341 static int fs_path_prepare_for_add(struct fs_path *p, int name_len)
346 new_len = p->end - p->start + name_len;
347 if (p->start != p->end)
349 ret = fs_path_ensure_buf(p, new_len);
354 if (p->start != p->end)
356 p->start -= name_len;
357 p->prepared = p->start;
359 if (p->start != p->end)
361 p->prepared = p->end;
370 static int fs_path_add(struct fs_path *p, const char *name, int name_len)
374 ret = fs_path_prepare_for_add(p, name_len);
377 memcpy(p->prepared, name, name_len);
384 static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
388 ret = fs_path_prepare_for_add(p, p2->end - p2->start);
391 memcpy(p->prepared, p2->start, p2->end - p2->start);
398 static int fs_path_add_from_extent_buffer(struct fs_path *p,
399 struct extent_buffer *eb,
400 unsigned long off, int len)
404 ret = fs_path_prepare_for_add(p, len);
408 read_extent_buffer(eb, p->prepared, off, len);
415 static int fs_path_copy(struct fs_path *p, struct fs_path *from)
419 p->reversed = from->reversed;
422 ret = fs_path_add_path(p, from);
428 static void fs_path_unreverse(struct fs_path *p)
437 len = p->end - p->start;
439 p->end = p->start + len;
440 memmove(p->start, tmp, len + 1);
444 static struct btrfs_path *alloc_path_for_send(void)
446 struct btrfs_path *path;
448 path = btrfs_alloc_path();
451 path->search_commit_root = 1;
452 path->skip_locking = 1;
456 static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
466 ret = vfs_write(filp, (char *)buf + pos, len - pos, off);
467 /* TODO handle that correctly */
468 /*if (ret == -ERESTARTSYS) {
487 static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
489 struct btrfs_tlv_header *hdr;
490 int total_len = sizeof(*hdr) + len;
491 int left = sctx->send_max_size - sctx->send_size;
493 if (unlikely(left < total_len))
496 hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
497 hdr->tlv_type = cpu_to_le16(attr);
498 hdr->tlv_len = cpu_to_le16(len);
499 memcpy(hdr + 1, data, len);
500 sctx->send_size += total_len;
505 #define TLV_PUT_DEFINE_INT(bits) \
506 static int tlv_put_u##bits(struct send_ctx *sctx, \
507 u##bits attr, u##bits value) \
509 __le##bits __tmp = cpu_to_le##bits(value); \
510 return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \
513 TLV_PUT_DEFINE_INT(64)
515 static int tlv_put_string(struct send_ctx *sctx, u16 attr,
516 const char *str, int len)
520 return tlv_put(sctx, attr, str, len);
523 static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
526 return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
529 static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
530 struct extent_buffer *eb,
531 struct btrfs_timespec *ts)
533 struct btrfs_timespec bts;
534 read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
535 return tlv_put(sctx, attr, &bts, sizeof(bts));
539 #define TLV_PUT(sctx, attrtype, attrlen, data) \
541 ret = tlv_put(sctx, attrtype, attrlen, data); \
543 goto tlv_put_failure; \
546 #define TLV_PUT_INT(sctx, attrtype, bits, value) \
548 ret = tlv_put_u##bits(sctx, attrtype, value); \
550 goto tlv_put_failure; \
553 #define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
554 #define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
555 #define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
556 #define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
557 #define TLV_PUT_STRING(sctx, attrtype, str, len) \
559 ret = tlv_put_string(sctx, attrtype, str, len); \
561 goto tlv_put_failure; \
563 #define TLV_PUT_PATH(sctx, attrtype, p) \
565 ret = tlv_put_string(sctx, attrtype, p->start, \
566 p->end - p->start); \
568 goto tlv_put_failure; \
570 #define TLV_PUT_UUID(sctx, attrtype, uuid) \
572 ret = tlv_put_uuid(sctx, attrtype, uuid); \
574 goto tlv_put_failure; \
576 #define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
578 ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
580 goto tlv_put_failure; \
583 static int send_header(struct send_ctx *sctx)
585 struct btrfs_stream_header hdr;
587 strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
588 hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
590 return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
595 * For each command/item we want to send to userspace, we call this function.
597 static int begin_cmd(struct send_ctx *sctx, int cmd)
599 struct btrfs_cmd_header *hdr;
601 if (WARN_ON(!sctx->send_buf))
604 BUG_ON(sctx->send_size);
606 sctx->send_size += sizeof(*hdr);
607 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
608 hdr->cmd = cpu_to_le16(cmd);
613 static int send_cmd(struct send_ctx *sctx)
616 struct btrfs_cmd_header *hdr;
619 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
620 hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
623 crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
624 hdr->crc = cpu_to_le32(crc);
626 ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
629 sctx->total_send_size += sctx->send_size;
630 sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
637 * Sends a move instruction to user space
639 static int send_rename(struct send_ctx *sctx,
640 struct fs_path *from, struct fs_path *to)
644 verbose_printk("btrfs: send_rename %s -> %s\n", from->start, to->start);
646 ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
650 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
651 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
653 ret = send_cmd(sctx);
661 * Sends a link instruction to user space
663 static int send_link(struct send_ctx *sctx,
664 struct fs_path *path, struct fs_path *lnk)
668 verbose_printk("btrfs: send_link %s -> %s\n", path->start, lnk->start);
670 ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
674 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
675 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
677 ret = send_cmd(sctx);
685 * Sends an unlink instruction to user space
687 static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
691 verbose_printk("btrfs: send_unlink %s\n", path->start);
693 ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
697 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
699 ret = send_cmd(sctx);
707 * Sends a rmdir instruction to user space
709 static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
713 verbose_printk("btrfs: send_rmdir %s\n", path->start);
715 ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
719 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
721 ret = send_cmd(sctx);
729 * Helper function to retrieve some fields from an inode item.
731 static int get_inode_info(struct btrfs_root *root,
732 u64 ino, u64 *size, u64 *gen,
733 u64 *mode, u64 *uid, u64 *gid,
737 struct btrfs_inode_item *ii;
738 struct btrfs_key key;
739 struct btrfs_path *path;
741 path = alloc_path_for_send();
746 key.type = BTRFS_INODE_ITEM_KEY;
748 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
756 ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
757 struct btrfs_inode_item);
759 *size = btrfs_inode_size(path->nodes[0], ii);
761 *gen = btrfs_inode_generation(path->nodes[0], ii);
763 *mode = btrfs_inode_mode(path->nodes[0], ii);
765 *uid = btrfs_inode_uid(path->nodes[0], ii);
767 *gid = btrfs_inode_gid(path->nodes[0], ii);
769 *rdev = btrfs_inode_rdev(path->nodes[0], ii);
772 btrfs_free_path(path);
776 typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
781 * Helper function to iterate the entries in ONE btrfs_inode_ref or
782 * btrfs_inode_extref.
783 * The iterate callback may return a non zero value to stop iteration. This can
784 * be a negative value for error codes or 1 to simply stop it.
786 * path must point to the INODE_REF or INODE_EXTREF when called.
788 static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
789 struct btrfs_key *found_key, int resolve,
790 iterate_inode_ref_t iterate, void *ctx)
792 struct extent_buffer *eb = path->nodes[0];
793 struct btrfs_item *item;
794 struct btrfs_inode_ref *iref;
795 struct btrfs_inode_extref *extref;
796 struct btrfs_path *tmp_path;
800 int slot = path->slots[0];
807 unsigned long name_off;
808 unsigned long elem_size;
811 p = fs_path_alloc_reversed();
815 tmp_path = alloc_path_for_send();
822 if (found_key->type == BTRFS_INODE_REF_KEY) {
823 ptr = (unsigned long)btrfs_item_ptr(eb, slot,
824 struct btrfs_inode_ref);
825 item = btrfs_item_nr(slot);
826 total = btrfs_item_size(eb, item);
827 elem_size = sizeof(*iref);
829 ptr = btrfs_item_ptr_offset(eb, slot);
830 total = btrfs_item_size_nr(eb, slot);
831 elem_size = sizeof(*extref);
834 while (cur < total) {
837 if (found_key->type == BTRFS_INODE_REF_KEY) {
838 iref = (struct btrfs_inode_ref *)(ptr + cur);
839 name_len = btrfs_inode_ref_name_len(eb, iref);
840 name_off = (unsigned long)(iref + 1);
841 index = btrfs_inode_ref_index(eb, iref);
842 dir = found_key->offset;
844 extref = (struct btrfs_inode_extref *)(ptr + cur);
845 name_len = btrfs_inode_extref_name_len(eb, extref);
846 name_off = (unsigned long)&extref->name;
847 index = btrfs_inode_extref_index(eb, extref);
848 dir = btrfs_inode_extref_parent(eb, extref);
852 start = btrfs_ref_to_path(root, tmp_path, name_len,
856 ret = PTR_ERR(start);
859 if (start < p->buf) {
860 /* overflow , try again with larger buffer */
861 ret = fs_path_ensure_buf(p,
862 p->buf_len + p->buf - start);
865 start = btrfs_ref_to_path(root, tmp_path,
870 ret = PTR_ERR(start);
873 BUG_ON(start < p->buf);
877 ret = fs_path_add_from_extent_buffer(p, eb, name_off,
883 cur += elem_size + name_len;
884 ret = iterate(num, dir, index, p, ctx);
891 btrfs_free_path(tmp_path);
896 typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
897 const char *name, int name_len,
898 const char *data, int data_len,
902 * Helper function to iterate the entries in ONE btrfs_dir_item.
903 * The iterate callback may return a non zero value to stop iteration. This can
904 * be a negative value for error codes or 1 to simply stop it.
906 * path must point to the dir item when called.
908 static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
909 struct btrfs_key *found_key,
910 iterate_dir_item_t iterate, void *ctx)
913 struct extent_buffer *eb;
914 struct btrfs_item *item;
915 struct btrfs_dir_item *di;
916 struct btrfs_key di_key;
931 buf = kmalloc(buf_len, GFP_NOFS);
938 slot = path->slots[0];
939 item = btrfs_item_nr(slot);
940 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
943 total = btrfs_item_size(eb, item);
946 while (cur < total) {
947 name_len = btrfs_dir_name_len(eb, di);
948 data_len = btrfs_dir_data_len(eb, di);
949 type = btrfs_dir_type(eb, di);
950 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
952 if (name_len + data_len > buf_len) {
953 buf_len = PAGE_ALIGN(name_len + data_len);
955 buf2 = vmalloc(buf_len);
962 buf2 = krealloc(buf, buf_len, GFP_NOFS);
964 buf2 = vmalloc(buf_len);
978 read_extent_buffer(eb, buf, (unsigned long)(di + 1),
979 name_len + data_len);
981 len = sizeof(*di) + name_len + data_len;
982 di = (struct btrfs_dir_item *)((char *)di + len);
985 ret = iterate(num, &di_key, buf, name_len, buf + name_len,
986 data_len, type, ctx);
1005 static int __copy_first_ref(int num, u64 dir, int index,
1006 struct fs_path *p, void *ctx)
1009 struct fs_path *pt = ctx;
1011 ret = fs_path_copy(pt, p);
1015 /* we want the first only */
1020 * Retrieve the first path of an inode. If an inode has more then one
1021 * ref/hardlink, this is ignored.
1023 static int get_inode_path(struct btrfs_root *root,
1024 u64 ino, struct fs_path *path)
1027 struct btrfs_key key, found_key;
1028 struct btrfs_path *p;
1030 p = alloc_path_for_send();
1034 fs_path_reset(path);
1037 key.type = BTRFS_INODE_REF_KEY;
1040 ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
1047 btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
1048 if (found_key.objectid != ino ||
1049 (found_key.type != BTRFS_INODE_REF_KEY &&
1050 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1055 ret = iterate_inode_ref(root, p, &found_key, 1,
1056 __copy_first_ref, path);
1066 struct backref_ctx {
1067 struct send_ctx *sctx;
1069 /* number of total found references */
1073 * used for clones found in send_root. clones found behind cur_objectid
1074 * and cur_offset are not considered as allowed clones.
1079 /* may be truncated in case it's the last extent in a file */
1082 /* Just to check for bugs in backref resolving */
1086 static int __clone_root_cmp_bsearch(const void *key, const void *elt)
1088 u64 root = (u64)(uintptr_t)key;
1089 struct clone_root *cr = (struct clone_root *)elt;
1091 if (root < cr->root->objectid)
1093 if (root > cr->root->objectid)
1098 static int __clone_root_cmp_sort(const void *e1, const void *e2)
1100 struct clone_root *cr1 = (struct clone_root *)e1;
1101 struct clone_root *cr2 = (struct clone_root *)e2;
1103 if (cr1->root->objectid < cr2->root->objectid)
1105 if (cr1->root->objectid > cr2->root->objectid)
1111 * Called for every backref that is found for the current extent.
1112 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1114 static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
1116 struct backref_ctx *bctx = ctx_;
1117 struct clone_root *found;
1121 /* First check if the root is in the list of accepted clone sources */
1122 found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1123 bctx->sctx->clone_roots_cnt,
1124 sizeof(struct clone_root),
1125 __clone_root_cmp_bsearch);
1129 if (found->root == bctx->sctx->send_root &&
1130 ino == bctx->cur_objectid &&
1131 offset == bctx->cur_offset) {
1132 bctx->found_itself = 1;
1136 * There are inodes that have extents that lie behind its i_size. Don't
1137 * accept clones from these extents.
1139 ret = get_inode_info(found->root, ino, &i_size, NULL, NULL, NULL, NULL,
1144 if (offset + bctx->extent_len > i_size)
1148 * Make sure we don't consider clones from send_root that are
1149 * behind the current inode/offset.
1151 if (found->root == bctx->sctx->send_root) {
1153 * TODO for the moment we don't accept clones from the inode
1154 * that is currently send. We may change this when
1155 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1158 if (ino >= bctx->cur_objectid)
1161 if (ino > bctx->cur_objectid)
1163 if (offset + bctx->extent_len > bctx->cur_offset)
1169 found->found_refs++;
1170 if (ino < found->ino) {
1172 found->offset = offset;
1173 } else if (found->ino == ino) {
1175 * same extent found more then once in the same file.
1177 if (found->offset > offset + bctx->extent_len)
1178 found->offset = offset;
1185 * Given an inode, offset and extent item, it finds a good clone for a clone
1186 * instruction. Returns -ENOENT when none could be found. The function makes
1187 * sure that the returned clone is usable at the point where sending is at the
1188 * moment. This means, that no clones are accepted which lie behind the current
1191 * path must point to the extent item when called.
1193 static int find_extent_clone(struct send_ctx *sctx,
1194 struct btrfs_path *path,
1195 u64 ino, u64 data_offset,
1197 struct clone_root **found)
1204 u64 extent_item_pos;
1206 struct btrfs_file_extent_item *fi;
1207 struct extent_buffer *eb = path->nodes[0];
1208 struct backref_ctx *backref_ctx = NULL;
1209 struct clone_root *cur_clone_root;
1210 struct btrfs_key found_key;
1211 struct btrfs_path *tmp_path;
1215 tmp_path = alloc_path_for_send();
1219 backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
1225 if (data_offset >= ino_size) {
1227 * There may be extents that lie behind the file's size.
1228 * I at least had this in combination with snapshotting while
1229 * writing large files.
1235 fi = btrfs_item_ptr(eb, path->slots[0],
1236 struct btrfs_file_extent_item);
1237 extent_type = btrfs_file_extent_type(eb, fi);
1238 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1242 compressed = btrfs_file_extent_compression(eb, fi);
1244 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1245 disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
1246 if (disk_byte == 0) {
1250 logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1252 ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path,
1253 &found_key, &flags);
1254 btrfs_release_path(tmp_path);
1258 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1264 * Setup the clone roots.
1266 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1267 cur_clone_root = sctx->clone_roots + i;
1268 cur_clone_root->ino = (u64)-1;
1269 cur_clone_root->offset = 0;
1270 cur_clone_root->found_refs = 0;
1273 backref_ctx->sctx = sctx;
1274 backref_ctx->found = 0;
1275 backref_ctx->cur_objectid = ino;
1276 backref_ctx->cur_offset = data_offset;
1277 backref_ctx->found_itself = 0;
1278 backref_ctx->extent_len = num_bytes;
1281 * The last extent of a file may be too large due to page alignment.
1282 * We need to adjust extent_len in this case so that the checks in
1283 * __iterate_backrefs work.
1285 if (data_offset + num_bytes >= ino_size)
1286 backref_ctx->extent_len = ino_size - data_offset;
1289 * Now collect all backrefs.
1291 if (compressed == BTRFS_COMPRESS_NONE)
1292 extent_item_pos = logical - found_key.objectid;
1294 extent_item_pos = 0;
1296 extent_item_pos = logical - found_key.objectid;
1297 ret = iterate_extent_inodes(sctx->send_root->fs_info,
1298 found_key.objectid, extent_item_pos, 1,
1299 __iterate_backrefs, backref_ctx);
1304 if (!backref_ctx->found_itself) {
1305 /* found a bug in backref code? */
1307 btrfs_err(sctx->send_root->fs_info, "did not find backref in "
1308 "send_root. inode=%llu, offset=%llu, "
1309 "disk_byte=%llu found extent=%llu\n",
1310 ino, data_offset, disk_byte, found_key.objectid);
1314 verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "
1316 "num_bytes=%llu, logical=%llu\n",
1317 data_offset, ino, num_bytes, logical);
1319 if (!backref_ctx->found)
1320 verbose_printk("btrfs: no clones found\n");
1322 cur_clone_root = NULL;
1323 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1324 if (sctx->clone_roots[i].found_refs) {
1325 if (!cur_clone_root)
1326 cur_clone_root = sctx->clone_roots + i;
1327 else if (sctx->clone_roots[i].root == sctx->send_root)
1328 /* prefer clones from send_root over others */
1329 cur_clone_root = sctx->clone_roots + i;
1334 if (cur_clone_root) {
1335 *found = cur_clone_root;
1342 btrfs_free_path(tmp_path);
1347 static int read_symlink(struct btrfs_root *root,
1349 struct fs_path *dest)
1352 struct btrfs_path *path;
1353 struct btrfs_key key;
1354 struct btrfs_file_extent_item *ei;
1360 path = alloc_path_for_send();
1365 key.type = BTRFS_EXTENT_DATA_KEY;
1367 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1372 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
1373 struct btrfs_file_extent_item);
1374 type = btrfs_file_extent_type(path->nodes[0], ei);
1375 compression = btrfs_file_extent_compression(path->nodes[0], ei);
1376 BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
1377 BUG_ON(compression);
1379 off = btrfs_file_extent_inline_start(ei);
1380 len = btrfs_file_extent_inline_len(path->nodes[0], path->slots[0], ei);
1382 ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
1385 btrfs_free_path(path);
1390 * Helper function to generate a file name that is unique in the root of
1391 * send_root and parent_root. This is used to generate names for orphan inodes.
1393 static int gen_unique_name(struct send_ctx *sctx,
1395 struct fs_path *dest)
1398 struct btrfs_path *path;
1399 struct btrfs_dir_item *di;
1404 path = alloc_path_for_send();
1409 len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
1411 if (len >= sizeof(tmp)) {
1412 /* should really not happen */
1417 di = btrfs_lookup_dir_item(NULL, sctx->send_root,
1418 path, BTRFS_FIRST_FREE_OBJECTID,
1419 tmp, strlen(tmp), 0);
1420 btrfs_release_path(path);
1426 /* not unique, try again */
1431 if (!sctx->parent_root) {
1437 di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
1438 path, BTRFS_FIRST_FREE_OBJECTID,
1439 tmp, strlen(tmp), 0);
1440 btrfs_release_path(path);
1446 /* not unique, try again */
1454 ret = fs_path_add(dest, tmp, strlen(tmp));
1457 btrfs_free_path(path);
1462 inode_state_no_change,
1463 inode_state_will_create,
1464 inode_state_did_create,
1465 inode_state_will_delete,
1466 inode_state_did_delete,
1469 static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
1477 ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1479 if (ret < 0 && ret != -ENOENT)
1483 if (!sctx->parent_root) {
1484 right_ret = -ENOENT;
1486 ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1487 NULL, NULL, NULL, NULL);
1488 if (ret < 0 && ret != -ENOENT)
1493 if (!left_ret && !right_ret) {
1494 if (left_gen == gen && right_gen == gen) {
1495 ret = inode_state_no_change;
1496 } else if (left_gen == gen) {
1497 if (ino < sctx->send_progress)
1498 ret = inode_state_did_create;
1500 ret = inode_state_will_create;
1501 } else if (right_gen == gen) {
1502 if (ino < sctx->send_progress)
1503 ret = inode_state_did_delete;
1505 ret = inode_state_will_delete;
1509 } else if (!left_ret) {
1510 if (left_gen == gen) {
1511 if (ino < sctx->send_progress)
1512 ret = inode_state_did_create;
1514 ret = inode_state_will_create;
1518 } else if (!right_ret) {
1519 if (right_gen == gen) {
1520 if (ino < sctx->send_progress)
1521 ret = inode_state_did_delete;
1523 ret = inode_state_will_delete;
1535 static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
1539 ret = get_cur_inode_state(sctx, ino, gen);
1543 if (ret == inode_state_no_change ||
1544 ret == inode_state_did_create ||
1545 ret == inode_state_will_delete)
1555 * Helper function to lookup a dir item in a dir.
1557 static int lookup_dir_item_inode(struct btrfs_root *root,
1558 u64 dir, const char *name, int name_len,
1563 struct btrfs_dir_item *di;
1564 struct btrfs_key key;
1565 struct btrfs_path *path;
1567 path = alloc_path_for_send();
1571 di = btrfs_lookup_dir_item(NULL, root, path,
1572 dir, name, name_len, 0);
1581 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1582 *found_inode = key.objectid;
1583 *found_type = btrfs_dir_type(path->nodes[0], di);
1586 btrfs_free_path(path);
1591 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
1592 * generation of the parent dir and the name of the dir entry.
1594 static int get_first_ref(struct btrfs_root *root, u64 ino,
1595 u64 *dir, u64 *dir_gen, struct fs_path *name)
1598 struct btrfs_key key;
1599 struct btrfs_key found_key;
1600 struct btrfs_path *path;
1604 path = alloc_path_for_send();
1609 key.type = BTRFS_INODE_REF_KEY;
1612 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
1616 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1618 if (ret || found_key.objectid != ino ||
1619 (found_key.type != BTRFS_INODE_REF_KEY &&
1620 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1625 if (key.type == BTRFS_INODE_REF_KEY) {
1626 struct btrfs_inode_ref *iref;
1627 iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1628 struct btrfs_inode_ref);
1629 len = btrfs_inode_ref_name_len(path->nodes[0], iref);
1630 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1631 (unsigned long)(iref + 1),
1633 parent_dir = found_key.offset;
1635 struct btrfs_inode_extref *extref;
1636 extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1637 struct btrfs_inode_extref);
1638 len = btrfs_inode_extref_name_len(path->nodes[0], extref);
1639 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1640 (unsigned long)&extref->name, len);
1641 parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
1645 btrfs_release_path(path);
1647 ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
1655 btrfs_free_path(path);
1659 static int is_first_ref(struct btrfs_root *root,
1661 const char *name, int name_len)
1664 struct fs_path *tmp_name;
1668 tmp_name = fs_path_alloc();
1672 ret = get_first_ref(root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
1676 if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1681 ret = !memcmp(tmp_name->start, name, name_len);
1684 fs_path_free(tmp_name);
1689 * Used by process_recorded_refs to determine if a new ref would overwrite an
1690 * already existing ref. In case it detects an overwrite, it returns the
1691 * inode/gen in who_ino/who_gen.
1692 * When an overwrite is detected, process_recorded_refs does proper orphanizing
1693 * to make sure later references to the overwritten inode are possible.
1694 * Orphanizing is however only required for the first ref of an inode.
1695 * process_recorded_refs does an additional is_first_ref check to see if
1696 * orphanizing is really required.
1698 static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
1699 const char *name, int name_len,
1700 u64 *who_ino, u64 *who_gen)
1704 u64 other_inode = 0;
1707 if (!sctx->parent_root)
1710 ret = is_inode_existent(sctx, dir, dir_gen);
1715 * If we have a parent root we need to verify that the parent dir was
1716 * not delted and then re-created, if it was then we have no overwrite
1717 * and we can just unlink this entry.
1719 if (sctx->parent_root) {
1720 ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
1722 if (ret < 0 && ret != -ENOENT)
1732 ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
1733 &other_inode, &other_type);
1734 if (ret < 0 && ret != -ENOENT)
1742 * Check if the overwritten ref was already processed. If yes, the ref
1743 * was already unlinked/moved, so we can safely assume that we will not
1744 * overwrite anything at this point in time.
1746 if (other_inode > sctx->send_progress) {
1747 ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1748 who_gen, NULL, NULL, NULL, NULL);
1753 *who_ino = other_inode;
1763 * Checks if the ref was overwritten by an already processed inode. This is
1764 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
1765 * thus the orphan name needs be used.
1766 * process_recorded_refs also uses it to avoid unlinking of refs that were
1769 static int did_overwrite_ref(struct send_ctx *sctx,
1770 u64 dir, u64 dir_gen,
1771 u64 ino, u64 ino_gen,
1772 const char *name, int name_len)
1779 if (!sctx->parent_root)
1782 ret = is_inode_existent(sctx, dir, dir_gen);
1786 /* check if the ref was overwritten by another ref */
1787 ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
1788 &ow_inode, &other_type);
1789 if (ret < 0 && ret != -ENOENT)
1792 /* was never and will never be overwritten */
1797 ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1802 if (ow_inode == ino && gen == ino_gen) {
1807 /* we know that it is or will be overwritten. check this now */
1808 if (ow_inode < sctx->send_progress)
1818 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
1819 * that got overwritten. This is used by process_recorded_refs to determine
1820 * if it has to use the path as returned by get_cur_path or the orphan name.
1822 static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
1825 struct fs_path *name = NULL;
1829 if (!sctx->parent_root)
1832 name = fs_path_alloc();
1836 ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
1840 ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
1841 name->start, fs_path_len(name));
1849 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
1850 * so we need to do some special handling in case we have clashes. This function
1851 * takes care of this with the help of name_cache_entry::radix_list.
1852 * In case of error, nce is kfreed.
1854 static int name_cache_insert(struct send_ctx *sctx,
1855 struct name_cache_entry *nce)
1858 struct list_head *nce_head;
1860 nce_head = radix_tree_lookup(&sctx->name_cache,
1861 (unsigned long)nce->ino);
1863 nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
1868 INIT_LIST_HEAD(nce_head);
1870 ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
1877 list_add_tail(&nce->radix_list, nce_head);
1878 list_add_tail(&nce->list, &sctx->name_cache_list);
1879 sctx->name_cache_size++;
1884 static void name_cache_delete(struct send_ctx *sctx,
1885 struct name_cache_entry *nce)
1887 struct list_head *nce_head;
1889 nce_head = radix_tree_lookup(&sctx->name_cache,
1890 (unsigned long)nce->ino);
1893 list_del(&nce->radix_list);
1894 list_del(&nce->list);
1895 sctx->name_cache_size--;
1897 if (list_empty(nce_head)) {
1898 radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
1903 static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
1906 struct list_head *nce_head;
1907 struct name_cache_entry *cur;
1909 nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
1913 list_for_each_entry(cur, nce_head, radix_list) {
1914 if (cur->ino == ino && cur->gen == gen)
1921 * Removes the entry from the list and adds it back to the end. This marks the
1922 * entry as recently used so that name_cache_clean_unused does not remove it.
1924 static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
1926 list_del(&nce->list);
1927 list_add_tail(&nce->list, &sctx->name_cache_list);
1931 * Remove some entries from the beginning of name_cache_list.
1933 static void name_cache_clean_unused(struct send_ctx *sctx)
1935 struct name_cache_entry *nce;
1937 if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
1940 while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
1941 nce = list_entry(sctx->name_cache_list.next,
1942 struct name_cache_entry, list);
1943 name_cache_delete(sctx, nce);
1948 static void name_cache_free(struct send_ctx *sctx)
1950 struct name_cache_entry *nce;
1952 while (!list_empty(&sctx->name_cache_list)) {
1953 nce = list_entry(sctx->name_cache_list.next,
1954 struct name_cache_entry, list);
1955 name_cache_delete(sctx, nce);
1961 * Used by get_cur_path for each ref up to the root.
1962 * Returns 0 if it succeeded.
1963 * Returns 1 if the inode is not existent or got overwritten. In that case, the
1964 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
1965 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
1966 * Returns <0 in case of error.
1968 static int __get_cur_name_and_parent(struct send_ctx *sctx,
1970 int skip_name_cache,
1973 struct fs_path *dest)
1977 struct btrfs_path *path = NULL;
1978 struct name_cache_entry *nce = NULL;
1980 if (skip_name_cache)
1983 * First check if we already did a call to this function with the same
1984 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
1985 * return the cached result.
1987 nce = name_cache_search(sctx, ino, gen);
1989 if (ino < sctx->send_progress && nce->need_later_update) {
1990 name_cache_delete(sctx, nce);
1994 name_cache_used(sctx, nce);
1995 *parent_ino = nce->parent_ino;
1996 *parent_gen = nce->parent_gen;
1997 ret = fs_path_add(dest, nce->name, nce->name_len);
2005 path = alloc_path_for_send();
2010 * If the inode is not existent yet, add the orphan name and return 1.
2011 * This should only happen for the parent dir that we determine in
2014 ret = is_inode_existent(sctx, ino, gen);
2019 ret = gen_unique_name(sctx, ino, gen, dest);
2028 * Depending on whether the inode was already processed or not, use
2029 * send_root or parent_root for ref lookup.
2031 if (ino < sctx->send_progress && !skip_name_cache)
2032 ret = get_first_ref(sctx->send_root, ino,
2033 parent_ino, parent_gen, dest);
2035 ret = get_first_ref(sctx->parent_root, ino,
2036 parent_ino, parent_gen, dest);
2041 * Check if the ref was overwritten by an inode's ref that was processed
2042 * earlier. If yes, treat as orphan and return 1.
2044 ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
2045 dest->start, dest->end - dest->start);
2049 fs_path_reset(dest);
2050 ret = gen_unique_name(sctx, ino, gen, dest);
2055 if (skip_name_cache)
2060 * Store the result of the lookup in the name cache.
2062 nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS);
2070 nce->parent_ino = *parent_ino;
2071 nce->parent_gen = *parent_gen;
2072 nce->name_len = fs_path_len(dest);
2074 strcpy(nce->name, dest->start);
2076 if (ino < sctx->send_progress)
2077 nce->need_later_update = 0;
2079 nce->need_later_update = 1;
2081 nce_ret = name_cache_insert(sctx, nce);
2084 name_cache_clean_unused(sctx);
2087 btrfs_free_path(path);
2092 * Magic happens here. This function returns the first ref to an inode as it
2093 * would look like while receiving the stream at this point in time.
2094 * We walk the path up to the root. For every inode in between, we check if it
2095 * was already processed/sent. If yes, we continue with the parent as found
2096 * in send_root. If not, we continue with the parent as found in parent_root.
2097 * If we encounter an inode that was deleted at this point in time, we use the
2098 * inodes "orphan" name instead of the real name and stop. Same with new inodes
2099 * that were not created yet and overwritten inodes/refs.
2101 * When do we have have orphan inodes:
2102 * 1. When an inode is freshly created and thus no valid refs are available yet
2103 * 2. When a directory lost all it's refs (deleted) but still has dir items
2104 * inside which were not processed yet (pending for move/delete). If anyone
2105 * tried to get the path to the dir items, it would get a path inside that
2107 * 3. When an inode is moved around or gets new links, it may overwrite the ref
2108 * of an unprocessed inode. If in that case the first ref would be
2109 * overwritten, the overwritten inode gets "orphanized". Later when we
2110 * process this overwritten inode, it is restored at a new place by moving
2113 * sctx->send_progress tells this function at which point in time receiving
2116 static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
2117 struct fs_path *dest)
2120 struct fs_path *name = NULL;
2121 u64 parent_inode = 0;
2124 u64 start_ino = ino;
2125 u64 start_gen = gen;
2126 int skip_name_cache = 0;
2128 name = fs_path_alloc();
2134 if (is_waiting_for_move(sctx, ino))
2135 skip_name_cache = 1;
2139 fs_path_reset(dest);
2141 while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
2142 fs_path_reset(name);
2144 ret = __get_cur_name_and_parent(sctx, ino, gen, skip_name_cache,
2145 &parent_inode, &parent_gen, name);
2151 if (!skip_name_cache &&
2152 is_waiting_for_move(sctx, parent_inode)) {
2156 skip_name_cache = 1;
2160 ret = fs_path_add_path(dest, name);
2171 fs_path_unreverse(dest);
2176 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2178 static int send_subvol_begin(struct send_ctx *sctx)
2181 struct btrfs_root *send_root = sctx->send_root;
2182 struct btrfs_root *parent_root = sctx->parent_root;
2183 struct btrfs_path *path;
2184 struct btrfs_key key;
2185 struct btrfs_root_ref *ref;
2186 struct extent_buffer *leaf;
2190 path = btrfs_alloc_path();
2194 name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS);
2196 btrfs_free_path(path);
2200 key.objectid = send_root->objectid;
2201 key.type = BTRFS_ROOT_BACKREF_KEY;
2204 ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
2213 leaf = path->nodes[0];
2214 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2215 if (key.type != BTRFS_ROOT_BACKREF_KEY ||
2216 key.objectid != send_root->objectid) {
2220 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
2221 namelen = btrfs_root_ref_name_len(leaf, ref);
2222 read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
2223 btrfs_release_path(path);
2226 ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
2230 ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
2235 TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
2236 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2237 sctx->send_root->root_item.uuid);
2238 TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2239 le64_to_cpu(sctx->send_root->root_item.ctransid));
2241 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2242 sctx->parent_root->root_item.uuid);
2243 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2244 le64_to_cpu(sctx->parent_root->root_item.ctransid));
2247 ret = send_cmd(sctx);
2251 btrfs_free_path(path);
2256 static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
2261 verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino, size);
2263 p = fs_path_alloc();
2267 ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
2271 ret = get_cur_path(sctx, ino, gen, p);
2274 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2275 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
2277 ret = send_cmd(sctx);
2285 static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
2290 verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino, mode);
2292 p = fs_path_alloc();
2296 ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
2300 ret = get_cur_path(sctx, ino, gen, p);
2303 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2304 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
2306 ret = send_cmd(sctx);
2314 static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
2319 verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino, uid, gid);
2321 p = fs_path_alloc();
2325 ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
2329 ret = get_cur_path(sctx, ino, gen, p);
2332 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2333 TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
2334 TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
2336 ret = send_cmd(sctx);
2344 static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
2347 struct fs_path *p = NULL;
2348 struct btrfs_inode_item *ii;
2349 struct btrfs_path *path = NULL;
2350 struct extent_buffer *eb;
2351 struct btrfs_key key;
2354 verbose_printk("btrfs: send_utimes %llu\n", ino);
2356 p = fs_path_alloc();
2360 path = alloc_path_for_send();
2367 key.type = BTRFS_INODE_ITEM_KEY;
2369 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2373 eb = path->nodes[0];
2374 slot = path->slots[0];
2375 ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2377 ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
2381 ret = get_cur_path(sctx, ino, gen, p);
2384 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2385 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb,
2386 btrfs_inode_atime(ii));
2387 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb,
2388 btrfs_inode_mtime(ii));
2389 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb,
2390 btrfs_inode_ctime(ii));
2391 /* TODO Add otime support when the otime patches get into upstream */
2393 ret = send_cmd(sctx);
2398 btrfs_free_path(path);
2403 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2404 * a valid path yet because we did not process the refs yet. So, the inode
2405 * is created as orphan.
2407 static int send_create_inode(struct send_ctx *sctx, u64 ino)
2416 verbose_printk("btrfs: send_create_inode %llu\n", ino);
2418 p = fs_path_alloc();
2422 ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode, NULL,
2427 if (S_ISREG(mode)) {
2428 cmd = BTRFS_SEND_C_MKFILE;
2429 } else if (S_ISDIR(mode)) {
2430 cmd = BTRFS_SEND_C_MKDIR;
2431 } else if (S_ISLNK(mode)) {
2432 cmd = BTRFS_SEND_C_SYMLINK;
2433 } else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2434 cmd = BTRFS_SEND_C_MKNOD;
2435 } else if (S_ISFIFO(mode)) {
2436 cmd = BTRFS_SEND_C_MKFIFO;
2437 } else if (S_ISSOCK(mode)) {
2438 cmd = BTRFS_SEND_C_MKSOCK;
2440 printk(KERN_WARNING "btrfs: unexpected inode type %o",
2441 (int)(mode & S_IFMT));
2446 ret = begin_cmd(sctx, cmd);
2450 ret = gen_unique_name(sctx, ino, gen, p);
2454 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2455 TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2457 if (S_ISLNK(mode)) {
2459 ret = read_symlink(sctx->send_root, ino, p);
2462 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
2463 } else if (S_ISCHR(mode) || S_ISBLK(mode) ||
2464 S_ISFIFO(mode) || S_ISSOCK(mode)) {
2465 TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
2466 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2469 ret = send_cmd(sctx);
2481 * We need some special handling for inodes that get processed before the parent
2482 * directory got created. See process_recorded_refs for details.
2483 * This function does the check if we already created the dir out of order.
2485 static int did_create_dir(struct send_ctx *sctx, u64 dir)
2488 struct btrfs_path *path = NULL;
2489 struct btrfs_key key;
2490 struct btrfs_key found_key;
2491 struct btrfs_key di_key;
2492 struct extent_buffer *eb;
2493 struct btrfs_dir_item *di;
2496 path = alloc_path_for_send();
2503 key.type = BTRFS_DIR_INDEX_KEY;
2506 ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
2511 eb = path->nodes[0];
2512 slot = path->slots[0];
2513 btrfs_item_key_to_cpu(eb, &found_key, slot);
2515 if (ret || found_key.objectid != key.objectid ||
2516 found_key.type != key.type) {
2521 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2522 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2524 if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
2525 di_key.objectid < sctx->send_progress) {
2530 key.offset = found_key.offset + 1;
2531 btrfs_release_path(path);
2535 btrfs_free_path(path);
2540 * Only creates the inode if it is:
2541 * 1. Not a directory
2542 * 2. Or a directory which was not created already due to out of order
2543 * directories. See did_create_dir and process_recorded_refs for details.
2545 static int send_create_inode_if_needed(struct send_ctx *sctx)
2549 if (S_ISDIR(sctx->cur_inode_mode)) {
2550 ret = did_create_dir(sctx, sctx->cur_ino);
2559 ret = send_create_inode(sctx, sctx->cur_ino);
2567 struct recorded_ref {
2568 struct list_head list;
2571 struct fs_path *full_path;
2579 * We need to process new refs before deleted refs, but compare_tree gives us
2580 * everything mixed. So we first record all refs and later process them.
2581 * This function is a helper to record one ref.
2583 static int record_ref(struct list_head *head, u64 dir,
2584 u64 dir_gen, struct fs_path *path)
2586 struct recorded_ref *ref;
2588 ref = kmalloc(sizeof(*ref), GFP_NOFS);
2593 ref->dir_gen = dir_gen;
2594 ref->full_path = path;
2596 ref->name = (char *)kbasename(ref->full_path->start);
2597 ref->name_len = ref->full_path->end - ref->name;
2598 ref->dir_path = ref->full_path->start;
2599 if (ref->name == ref->full_path->start)
2600 ref->dir_path_len = 0;
2602 ref->dir_path_len = ref->full_path->end -
2603 ref->full_path->start - 1 - ref->name_len;
2605 list_add_tail(&ref->list, head);
2609 static int dup_ref(struct recorded_ref *ref, struct list_head *list)
2611 struct recorded_ref *new;
2613 new = kmalloc(sizeof(*ref), GFP_NOFS);
2617 new->dir = ref->dir;
2618 new->dir_gen = ref->dir_gen;
2619 new->full_path = NULL;
2620 INIT_LIST_HEAD(&new->list);
2621 list_add_tail(&new->list, list);
2625 static void __free_recorded_refs(struct list_head *head)
2627 struct recorded_ref *cur;
2629 while (!list_empty(head)) {
2630 cur = list_entry(head->next, struct recorded_ref, list);
2631 fs_path_free(cur->full_path);
2632 list_del(&cur->list);
2637 static void free_recorded_refs(struct send_ctx *sctx)
2639 __free_recorded_refs(&sctx->new_refs);
2640 __free_recorded_refs(&sctx->deleted_refs);
2644 * Renames/moves a file/dir to its orphan name. Used when the first
2645 * ref of an unprocessed inode gets overwritten and for all non empty
2648 static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
2649 struct fs_path *path)
2652 struct fs_path *orphan;
2654 orphan = fs_path_alloc();
2658 ret = gen_unique_name(sctx, ino, gen, orphan);
2662 ret = send_rename(sctx, path, orphan);
2665 fs_path_free(orphan);
2670 * Returns 1 if a directory can be removed at this point in time.
2671 * We check this by iterating all dir items and checking if the inode behind
2672 * the dir item was already processed.
2674 static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 send_progress)
2677 struct btrfs_root *root = sctx->parent_root;
2678 struct btrfs_path *path;
2679 struct btrfs_key key;
2680 struct btrfs_key found_key;
2681 struct btrfs_key loc;
2682 struct btrfs_dir_item *di;
2685 * Don't try to rmdir the top/root subvolume dir.
2687 if (dir == BTRFS_FIRST_FREE_OBJECTID)
2690 path = alloc_path_for_send();
2695 key.type = BTRFS_DIR_INDEX_KEY;
2699 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
2703 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2706 if (ret || found_key.objectid != key.objectid ||
2707 found_key.type != key.type) {
2711 di = btrfs_item_ptr(path->nodes[0], path->slots[0],
2712 struct btrfs_dir_item);
2713 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
2715 if (loc.objectid > send_progress) {
2720 btrfs_release_path(path);
2721 key.offset = found_key.offset + 1;
2727 btrfs_free_path(path);
2731 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
2733 struct rb_node *n = sctx->waiting_dir_moves.rb_node;
2734 struct waiting_dir_move *entry;
2737 entry = rb_entry(n, struct waiting_dir_move, node);
2738 if (ino < entry->ino)
2740 else if (ino > entry->ino)
2748 static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2750 struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
2751 struct rb_node *parent = NULL;
2752 struct waiting_dir_move *entry, *dm;
2754 dm = kmalloc(sizeof(*dm), GFP_NOFS);
2761 entry = rb_entry(parent, struct waiting_dir_move, node);
2762 if (ino < entry->ino) {
2764 } else if (ino > entry->ino) {
2765 p = &(*p)->rb_right;
2772 rb_link_node(&dm->node, parent, p);
2773 rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
2777 static int del_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2779 struct rb_node *n = sctx->waiting_dir_moves.rb_node;
2780 struct waiting_dir_move *entry;
2783 entry = rb_entry(n, struct waiting_dir_move, node);
2784 if (ino < entry->ino) {
2786 } else if (ino > entry->ino) {
2789 rb_erase(&entry->node, &sctx->waiting_dir_moves);
2797 static int add_pending_dir_move(struct send_ctx *sctx, u64 parent_ino)
2799 struct rb_node **p = &sctx->pending_dir_moves.rb_node;
2800 struct rb_node *parent = NULL;
2801 struct pending_dir_move *entry, *pm;
2802 struct recorded_ref *cur;
2806 pm = kmalloc(sizeof(*pm), GFP_NOFS);
2809 pm->parent_ino = parent_ino;
2810 pm->ino = sctx->cur_ino;
2811 pm->gen = sctx->cur_inode_gen;
2812 INIT_LIST_HEAD(&pm->list);
2813 INIT_LIST_HEAD(&pm->update_refs);
2814 RB_CLEAR_NODE(&pm->node);
2818 entry = rb_entry(parent, struct pending_dir_move, node);
2819 if (parent_ino < entry->parent_ino) {
2821 } else if (parent_ino > entry->parent_ino) {
2822 p = &(*p)->rb_right;
2829 list_for_each_entry(cur, &sctx->deleted_refs, list) {
2830 ret = dup_ref(cur, &pm->update_refs);
2834 list_for_each_entry(cur, &sctx->new_refs, list) {
2835 ret = dup_ref(cur, &pm->update_refs);
2840 ret = add_waiting_dir_move(sctx, pm->ino);
2845 list_add_tail(&pm->list, &entry->list);
2847 rb_link_node(&pm->node, parent, p);
2848 rb_insert_color(&pm->node, &sctx->pending_dir_moves);
2853 __free_recorded_refs(&pm->update_refs);
2859 static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
2862 struct rb_node *n = sctx->pending_dir_moves.rb_node;
2863 struct pending_dir_move *entry;
2866 entry = rb_entry(n, struct pending_dir_move, node);
2867 if (parent_ino < entry->parent_ino)
2869 else if (parent_ino > entry->parent_ino)
2877 static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
2879 struct fs_path *from_path = NULL;
2880 struct fs_path *to_path = NULL;
2881 u64 orig_progress = sctx->send_progress;
2882 struct recorded_ref *cur;
2885 from_path = fs_path_alloc();
2889 sctx->send_progress = pm->ino;
2890 ret = get_cur_path(sctx, pm->ino, pm->gen, from_path);
2894 to_path = fs_path_alloc();
2900 sctx->send_progress = sctx->cur_ino + 1;
2901 ret = del_waiting_dir_move(sctx, pm->ino);
2904 ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
2908 ret = send_rename(sctx, from_path, to_path);
2912 ret = send_utimes(sctx, pm->ino, pm->gen);
2917 * After rename/move, need to update the utimes of both new parent(s)
2918 * and old parent(s).
2920 list_for_each_entry(cur, &pm->update_refs, list) {
2921 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
2927 fs_path_free(from_path);
2928 fs_path_free(to_path);
2929 sctx->send_progress = orig_progress;
2934 static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
2936 if (!list_empty(&m->list))
2938 if (!RB_EMPTY_NODE(&m->node))
2939 rb_erase(&m->node, &sctx->pending_dir_moves);
2940 __free_recorded_refs(&m->update_refs);
2944 static void tail_append_pending_moves(struct pending_dir_move *moves,
2945 struct list_head *stack)
2947 if (list_empty(&moves->list)) {
2948 list_add_tail(&moves->list, stack);
2951 list_splice_init(&moves->list, &list);
2952 list_add_tail(&moves->list, stack);
2953 list_splice_tail(&list, stack);
2957 static int apply_children_dir_moves(struct send_ctx *sctx)
2959 struct pending_dir_move *pm;
2960 struct list_head stack;
2961 u64 parent_ino = sctx->cur_ino;
2964 pm = get_pending_dir_moves(sctx, parent_ino);
2968 INIT_LIST_HEAD(&stack);
2969 tail_append_pending_moves(pm, &stack);
2971 while (!list_empty(&stack)) {
2972 pm = list_first_entry(&stack, struct pending_dir_move, list);
2973 parent_ino = pm->ino;
2974 ret = apply_dir_move(sctx, pm);
2975 free_pending_move(sctx, pm);
2978 pm = get_pending_dir_moves(sctx, parent_ino);
2980 tail_append_pending_moves(pm, &stack);
2985 while (!list_empty(&stack)) {
2986 pm = list_first_entry(&stack, struct pending_dir_move, list);
2987 free_pending_move(sctx, pm);
2992 static int wait_for_parent_move(struct send_ctx *sctx,
2993 struct recorded_ref *parent_ref)
2996 u64 ino = parent_ref->dir;
2997 u64 parent_ino_before, parent_ino_after;
2998 u64 new_gen, old_gen;
2999 struct fs_path *path_before = NULL;
3000 struct fs_path *path_after = NULL;
3003 if (parent_ref->dir <= sctx->cur_ino)
3006 if (is_waiting_for_move(sctx, ino))
3009 ret = get_inode_info(sctx->parent_root, ino, NULL, &old_gen,
3010 NULL, NULL, NULL, NULL);
3016 ret = get_inode_info(sctx->send_root, ino, NULL, &new_gen,
3017 NULL, NULL, NULL, NULL);
3021 if (new_gen != old_gen)
3024 path_before = fs_path_alloc();
3028 ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
3030 if (ret == -ENOENT) {
3033 } else if (ret < 0) {
3037 path_after = fs_path_alloc();
3043 ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3045 if (ret == -ENOENT) {
3048 } else if (ret < 0) {
3052 len1 = fs_path_len(path_before);
3053 len2 = fs_path_len(path_after);
3054 if ((parent_ino_before != parent_ino_after) && (len1 != len2 ||
3055 memcmp(path_before->start, path_after->start, len1))) {
3062 fs_path_free(path_before);
3063 fs_path_free(path_after);
3069 * This does all the move/link/unlink/rmdir magic.
3071 static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
3074 struct recorded_ref *cur;
3075 struct recorded_ref *cur2;
3076 struct list_head check_dirs;
3077 struct fs_path *valid_path = NULL;
3080 int did_overwrite = 0;
3083 verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
3086 * This should never happen as the root dir always has the same ref
3087 * which is always '..'
3089 BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
3090 INIT_LIST_HEAD(&check_dirs);
3092 valid_path = fs_path_alloc();
3099 * First, check if the first ref of the current inode was overwritten
3100 * before. If yes, we know that the current inode was already orphanized
3101 * and thus use the orphan name. If not, we can use get_cur_path to
3102 * get the path of the first ref as it would like while receiving at
3103 * this point in time.
3104 * New inodes are always orphan at the beginning, so force to use the
3105 * orphan name in this case.
3106 * The first ref is stored in valid_path and will be updated if it
3107 * gets moved around.
3109 if (!sctx->cur_inode_new) {
3110 ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
3111 sctx->cur_inode_gen);
3117 if (sctx->cur_inode_new || did_overwrite) {
3118 ret = gen_unique_name(sctx, sctx->cur_ino,
3119 sctx->cur_inode_gen, valid_path);
3124 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3130 list_for_each_entry(cur, &sctx->new_refs, list) {
3132 * We may have refs where the parent directory does not exist
3133 * yet. This happens if the parent directories inum is higher
3134 * the the current inum. To handle this case, we create the
3135 * parent directory out of order. But we need to check if this
3136 * did already happen before due to other refs in the same dir.
3138 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3141 if (ret == inode_state_will_create) {
3144 * First check if any of the current inodes refs did
3145 * already create the dir.
3147 list_for_each_entry(cur2, &sctx->new_refs, list) {
3150 if (cur2->dir == cur->dir) {
3157 * If that did not happen, check if a previous inode
3158 * did already create the dir.
3161 ret = did_create_dir(sctx, cur->dir);
3165 ret = send_create_inode(sctx, cur->dir);
3172 * Check if this new ref would overwrite the first ref of
3173 * another unprocessed inode. If yes, orphanize the
3174 * overwritten inode. If we find an overwritten ref that is
3175 * not the first ref, simply unlink it.
3177 ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3178 cur->name, cur->name_len,
3179 &ow_inode, &ow_gen);
3183 ret = is_first_ref(sctx->parent_root,
3184 ow_inode, cur->dir, cur->name,
3189 ret = orphanize_inode(sctx, ow_inode, ow_gen,
3194 ret = send_unlink(sctx, cur->full_path);
3201 * link/move the ref to the new place. If we have an orphan
3202 * inode, move it and update valid_path. If not, link or move
3203 * it depending on the inode mode.
3206 ret = send_rename(sctx, valid_path, cur->full_path);
3210 ret = fs_path_copy(valid_path, cur->full_path);
3214 if (S_ISDIR(sctx->cur_inode_mode)) {
3216 * Dirs can't be linked, so move it. For moved
3217 * dirs, we always have one new and one deleted
3218 * ref. The deleted ref is ignored later.
3220 if (wait_for_parent_move(sctx, cur)) {
3221 ret = add_pending_dir_move(sctx,
3225 ret = send_rename(sctx, valid_path,
3228 ret = fs_path_copy(valid_path,
3234 ret = send_link(sctx, cur->full_path,
3240 ret = dup_ref(cur, &check_dirs);
3245 if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
3247 * Check if we can already rmdir the directory. If not,
3248 * orphanize it. For every dir item inside that gets deleted
3249 * later, we do this check again and rmdir it then if possible.
3250 * See the use of check_dirs for more details.
3252 ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_ino);
3256 ret = send_rmdir(sctx, valid_path);
3259 } else if (!is_orphan) {
3260 ret = orphanize_inode(sctx, sctx->cur_ino,
3261 sctx->cur_inode_gen, valid_path);
3267 list_for_each_entry(cur, &sctx->deleted_refs, list) {
3268 ret = dup_ref(cur, &check_dirs);
3272 } else if (S_ISDIR(sctx->cur_inode_mode) &&
3273 !list_empty(&sctx->deleted_refs)) {
3275 * We have a moved dir. Add the old parent to check_dirs
3277 cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
3279 ret = dup_ref(cur, &check_dirs);
3282 } else if (!S_ISDIR(sctx->cur_inode_mode)) {
3284 * We have a non dir inode. Go through all deleted refs and
3285 * unlink them if they were not already overwritten by other
3288 list_for_each_entry(cur, &sctx->deleted_refs, list) {
3289 ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3290 sctx->cur_ino, sctx->cur_inode_gen,
3291 cur->name, cur->name_len);
3295 ret = send_unlink(sctx, cur->full_path);
3299 ret = dup_ref(cur, &check_dirs);
3304 * If the inode is still orphan, unlink the orphan. This may
3305 * happen when a previous inode did overwrite the first ref
3306 * of this inode and no new refs were added for the current
3307 * inode. Unlinking does not mean that the inode is deleted in
3308 * all cases. There may still be links to this inode in other
3312 ret = send_unlink(sctx, valid_path);
3319 * We did collect all parent dirs where cur_inode was once located. We
3320 * now go through all these dirs and check if they are pending for
3321 * deletion and if it's finally possible to perform the rmdir now.
3322 * We also update the inode stats of the parent dirs here.
3324 list_for_each_entry(cur, &check_dirs, list) {
3326 * In case we had refs into dirs that were not processed yet,
3327 * we don't need to do the utime and rmdir logic for these dirs.
3328 * The dir will be processed later.
3330 if (cur->dir > sctx->cur_ino)
3333 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3337 if (ret == inode_state_did_create ||
3338 ret == inode_state_no_change) {
3339 /* TODO delayed utimes */
3340 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3343 } else if (ret == inode_state_did_delete) {
3344 ret = can_rmdir(sctx, cur->dir, sctx->cur_ino);
3348 ret = get_cur_path(sctx, cur->dir,
3349 cur->dir_gen, valid_path);
3352 ret = send_rmdir(sctx, valid_path);
3362 __free_recorded_refs(&check_dirs);
3363 free_recorded_refs(sctx);
3364 fs_path_free(valid_path);
3368 static int __record_new_ref(int num, u64 dir, int index,
3369 struct fs_path *name,
3373 struct send_ctx *sctx = ctx;
3377 p = fs_path_alloc();
3381 ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL, NULL,
3386 ret = get_cur_path(sctx, dir, gen, p);
3389 ret = fs_path_add_path(p, name);
3393 ret = record_ref(&sctx->new_refs, dir, gen, p);
3401 static int __record_deleted_ref(int num, u64 dir, int index,
3402 struct fs_path *name,
3406 struct send_ctx *sctx = ctx;
3410 p = fs_path_alloc();
3414 ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL, NULL,
3419 ret = get_cur_path(sctx, dir, gen, p);
3422 ret = fs_path_add_path(p, name);
3426 ret = record_ref(&sctx->deleted_refs, dir, gen, p);
3434 static int record_new_ref(struct send_ctx *sctx)
3438 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3439 sctx->cmp_key, 0, __record_new_ref, sctx);
3448 static int record_deleted_ref(struct send_ctx *sctx)
3452 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3453 sctx->cmp_key, 0, __record_deleted_ref, sctx);
3462 struct find_ref_ctx {
3465 struct btrfs_root *root;
3466 struct fs_path *name;
3470 static int __find_iref(int num, u64 dir, int index,
3471 struct fs_path *name,
3474 struct find_ref_ctx *ctx = ctx_;
3478 if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
3479 strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
3481 * To avoid doing extra lookups we'll only do this if everything
3484 ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
3488 if (dir_gen != ctx->dir_gen)
3490 ctx->found_idx = num;
3496 static int find_iref(struct btrfs_root *root,
3497 struct btrfs_path *path,
3498 struct btrfs_key *key,
3499 u64 dir, u64 dir_gen, struct fs_path *name)
3502 struct find_ref_ctx ctx;
3506 ctx.dir_gen = dir_gen;
3510 ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
3514 if (ctx.found_idx == -1)
3517 return ctx.found_idx;
3520 static int __record_changed_new_ref(int num, u64 dir, int index,
3521 struct fs_path *name,
3526 struct send_ctx *sctx = ctx;
3528 ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
3533 ret = find_iref(sctx->parent_root, sctx->right_path,
3534 sctx->cmp_key, dir, dir_gen, name);
3536 ret = __record_new_ref(num, dir, index, name, sctx);
3543 static int __record_changed_deleted_ref(int num, u64 dir, int index,
3544 struct fs_path *name,
3549 struct send_ctx *sctx = ctx;
3551 ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
3556 ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
3557 dir, dir_gen, name);
3559 ret = __record_deleted_ref(num, dir, index, name, sctx);
3566 static int record_changed_ref(struct send_ctx *sctx)
3570 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3571 sctx->cmp_key, 0, __record_changed_new_ref, sctx);
3574 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3575 sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
3585 * Record and process all refs at once. Needed when an inode changes the
3586 * generation number, which means that it was deleted and recreated.
3588 static int process_all_refs(struct send_ctx *sctx,
3589 enum btrfs_compare_tree_result cmd)
3592 struct btrfs_root *root;
3593 struct btrfs_path *path;
3594 struct btrfs_key key;
3595 struct btrfs_key found_key;
3596 struct extent_buffer *eb;
3598 iterate_inode_ref_t cb;
3599 int pending_move = 0;
3601 path = alloc_path_for_send();
3605 if (cmd == BTRFS_COMPARE_TREE_NEW) {
3606 root = sctx->send_root;
3607 cb = __record_new_ref;
3608 } else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
3609 root = sctx->parent_root;
3610 cb = __record_deleted_ref;
3615 key.objectid = sctx->cmp_key->objectid;
3616 key.type = BTRFS_INODE_REF_KEY;
3619 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3625 eb = path->nodes[0];
3626 slot = path->slots[0];
3627 btrfs_item_key_to_cpu(eb, &found_key, slot);
3629 if (found_key.objectid != key.objectid ||
3630 (found_key.type != BTRFS_INODE_REF_KEY &&
3631 found_key.type != BTRFS_INODE_EXTREF_KEY))
3634 ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
3635 btrfs_release_path(path);
3639 key.offset = found_key.offset + 1;
3641 btrfs_release_path(path);
3643 ret = process_recorded_refs(sctx, &pending_move);
3644 /* Only applicable to an incremental send. */
3645 ASSERT(pending_move == 0);
3648 btrfs_free_path(path);
3652 static int send_set_xattr(struct send_ctx *sctx,
3653 struct fs_path *path,
3654 const char *name, int name_len,
3655 const char *data, int data_len)
3659 ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
3663 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3664 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3665 TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
3667 ret = send_cmd(sctx);
3674 static int send_remove_xattr(struct send_ctx *sctx,
3675 struct fs_path *path,
3676 const char *name, int name_len)
3680 ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
3684 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3685 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3687 ret = send_cmd(sctx);
3694 static int __process_new_xattr(int num, struct btrfs_key *di_key,
3695 const char *name, int name_len,
3696 const char *data, int data_len,
3700 struct send_ctx *sctx = ctx;
3702 posix_acl_xattr_header dummy_acl;
3704 p = fs_path_alloc();
3709 * This hack is needed because empty acl's are stored as zero byte
3710 * data in xattrs. Problem with that is, that receiving these zero byte
3711 * acl's will fail later. To fix this, we send a dummy acl list that
3712 * only contains the version number and no entries.
3714 if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
3715 !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
3716 if (data_len == 0) {
3717 dummy_acl.a_version =
3718 cpu_to_le32(POSIX_ACL_XATTR_VERSION);
3719 data = (char *)&dummy_acl;
3720 data_len = sizeof(dummy_acl);
3724 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3728 ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
3735 static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
3736 const char *name, int name_len,
3737 const char *data, int data_len,
3741 struct send_ctx *sctx = ctx;
3744 p = fs_path_alloc();
3748 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3752 ret = send_remove_xattr(sctx, p, name, name_len);
3759 static int process_new_xattr(struct send_ctx *sctx)
3763 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
3764 sctx->cmp_key, __process_new_xattr, sctx);
3769 static int process_deleted_xattr(struct send_ctx *sctx)
3773 ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
3774 sctx->cmp_key, __process_deleted_xattr, sctx);
3779 struct find_xattr_ctx {
3787 static int __find_xattr(int num, struct btrfs_key *di_key,
3788 const char *name, int name_len,
3789 const char *data, int data_len,
3790 u8 type, void *vctx)
3792 struct find_xattr_ctx *ctx = vctx;
3794 if (name_len == ctx->name_len &&
3795 strncmp(name, ctx->name, name_len) == 0) {
3796 ctx->found_idx = num;
3797 ctx->found_data_len = data_len;
3798 ctx->found_data = kmemdup(data, data_len, GFP_NOFS);
3799 if (!ctx->found_data)
3806 static int find_xattr(struct btrfs_root *root,
3807 struct btrfs_path *path,
3808 struct btrfs_key *key,
3809 const char *name, int name_len,
3810 char **data, int *data_len)
3813 struct find_xattr_ctx ctx;
3816 ctx.name_len = name_len;
3818 ctx.found_data = NULL;
3819 ctx.found_data_len = 0;
3821 ret = iterate_dir_item(root, path, key, __find_xattr, &ctx);
3825 if (ctx.found_idx == -1)
3828 *data = ctx.found_data;
3829 *data_len = ctx.found_data_len;
3831 kfree(ctx.found_data);
3833 return ctx.found_idx;
3837 static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
3838 const char *name, int name_len,
3839 const char *data, int data_len,
3843 struct send_ctx *sctx = ctx;
3844 char *found_data = NULL;
3845 int found_data_len = 0;
3847 ret = find_xattr(sctx->parent_root, sctx->right_path,
3848 sctx->cmp_key, name, name_len, &found_data,
3850 if (ret == -ENOENT) {
3851 ret = __process_new_xattr(num, di_key, name, name_len, data,
3852 data_len, type, ctx);
3853 } else if (ret >= 0) {
3854 if (data_len != found_data_len ||
3855 memcmp(data, found_data, data_len)) {
3856 ret = __process_new_xattr(num, di_key, name, name_len,
3857 data, data_len, type, ctx);
3867 static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
3868 const char *name, int name_len,
3869 const char *data, int data_len,
3873 struct send_ctx *sctx = ctx;
3875 ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
3876 name, name_len, NULL, NULL);
3878 ret = __process_deleted_xattr(num, di_key, name, name_len, data,
3879 data_len, type, ctx);
3886 static int process_changed_xattr(struct send_ctx *sctx)
3890 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
3891 sctx->cmp_key, __process_changed_new_xattr, sctx);
3894 ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
3895 sctx->cmp_key, __process_changed_deleted_xattr, sctx);
3901 static int process_all_new_xattrs(struct send_ctx *sctx)
3904 struct btrfs_root *root;
3905 struct btrfs_path *path;
3906 struct btrfs_key key;
3907 struct btrfs_key found_key;
3908 struct extent_buffer *eb;
3911 path = alloc_path_for_send();
3915 root = sctx->send_root;
3917 key.objectid = sctx->cmp_key->objectid;
3918 key.type = BTRFS_XATTR_ITEM_KEY;
3921 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
3929 eb = path->nodes[0];
3930 slot = path->slots[0];
3931 btrfs_item_key_to_cpu(eb, &found_key, slot);
3933 if (found_key.objectid != key.objectid ||
3934 found_key.type != key.type) {
3939 ret = iterate_dir_item(root, path, &found_key,
3940 __process_new_xattr, sctx);
3944 btrfs_release_path(path);
3945 key.offset = found_key.offset + 1;
3949 btrfs_free_path(path);
3953 static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
3955 struct btrfs_root *root = sctx->send_root;
3956 struct btrfs_fs_info *fs_info = root->fs_info;
3957 struct inode *inode;
3960 struct btrfs_key key;
3961 pgoff_t index = offset >> PAGE_CACHE_SHIFT;
3963 unsigned pg_offset = offset & ~PAGE_CACHE_MASK;
3966 key.objectid = sctx->cur_ino;
3967 key.type = BTRFS_INODE_ITEM_KEY;
3970 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3972 return PTR_ERR(inode);
3974 if (offset + len > i_size_read(inode)) {
3975 if (offset > i_size_read(inode))
3978 len = offset - i_size_read(inode);
3983 last_index = (offset + len - 1) >> PAGE_CACHE_SHIFT;
3984 while (index <= last_index) {
3985 unsigned cur_len = min_t(unsigned, len,
3986 PAGE_CACHE_SIZE - pg_offset);
3987 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
3993 if (!PageUptodate(page)) {
3994 btrfs_readpage(NULL, page);
3996 if (!PageUptodate(page)) {
3998 page_cache_release(page);
4005 memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len);
4008 page_cache_release(page);
4020 * Read some bytes from the current inode/file and send a write command to
4023 static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
4027 ssize_t num_read = 0;
4029 p = fs_path_alloc();
4033 verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len);
4035 num_read = fill_read_buf(sctx, offset, len);
4036 if (num_read <= 0) {
4042 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4046 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4050 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4051 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4052 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
4054 ret = send_cmd(sctx);
4065 * Send a clone command to user space.
4067 static int send_clone(struct send_ctx *sctx,
4068 u64 offset, u32 len,
4069 struct clone_root *clone_root)
4075 verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, "
4076 "clone_inode=%llu, clone_offset=%llu\n", offset, len,
4077 clone_root->root->objectid, clone_root->ino,
4078 clone_root->offset);
4080 p = fs_path_alloc();
4084 ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
4088 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4092 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4093 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
4094 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4096 if (clone_root->root == sctx->send_root) {
4097 ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
4098 &gen, NULL, NULL, NULL, NULL);
4101 ret = get_cur_path(sctx, clone_root->ino, gen, p);
4103 ret = get_inode_path(clone_root->root, clone_root->ino, p);
4108 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4109 clone_root->root->root_item.uuid);
4110 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
4111 le64_to_cpu(clone_root->root->root_item.ctransid));
4112 TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
4113 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
4114 clone_root->offset);
4116 ret = send_cmd(sctx);
4125 * Send an update extent command to user space.
4127 static int send_update_extent(struct send_ctx *sctx,
4128 u64 offset, u32 len)
4133 p = fs_path_alloc();
4137 ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
4141 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4145 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4146 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4147 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);
4149 ret = send_cmd(sctx);
4157 static int send_hole(struct send_ctx *sctx, u64 end)
4159 struct fs_path *p = NULL;
4160 u64 offset = sctx->cur_inode_last_extent;
4164 p = fs_path_alloc();
4167 memset(sctx->read_buf, 0, BTRFS_SEND_READ_SIZE);
4168 while (offset < end) {
4169 len = min_t(u64, end - offset, BTRFS_SEND_READ_SIZE);
4171 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4174 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4177 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4178 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4179 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len);
4180 ret = send_cmd(sctx);
4190 static int send_write_or_clone(struct send_ctx *sctx,
4191 struct btrfs_path *path,
4192 struct btrfs_key *key,
4193 struct clone_root *clone_root)
4196 struct btrfs_file_extent_item *ei;
4197 u64 offset = key->offset;
4202 u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
4204 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4205 struct btrfs_file_extent_item);
4206 type = btrfs_file_extent_type(path->nodes[0], ei);
4207 if (type == BTRFS_FILE_EXTENT_INLINE) {
4208 len = btrfs_file_extent_inline_len(path->nodes[0],
4209 path->slots[0], ei);
4211 * it is possible the inline item won't cover the whole page,
4212 * but there may be items after this page. Make
4213 * sure to send the whole thing
4215 len = PAGE_CACHE_ALIGN(len);
4217 len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
4220 if (offset + len > sctx->cur_inode_size)
4221 len = sctx->cur_inode_size - offset;
4227 if (clone_root && IS_ALIGNED(offset + len, bs)) {
4228 ret = send_clone(sctx, offset, len, clone_root);
4229 } else if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) {
4230 ret = send_update_extent(sctx, offset, len);
4234 if (l > BTRFS_SEND_READ_SIZE)
4235 l = BTRFS_SEND_READ_SIZE;
4236 ret = send_write(sctx, pos + offset, l);
4249 static int is_extent_unchanged(struct send_ctx *sctx,
4250 struct btrfs_path *left_path,
4251 struct btrfs_key *ekey)
4254 struct btrfs_key key;
4255 struct btrfs_path *path = NULL;
4256 struct extent_buffer *eb;
4258 struct btrfs_key found_key;
4259 struct btrfs_file_extent_item *ei;
4264 u64 left_offset_fixed;
4272 path = alloc_path_for_send();
4276 eb = left_path->nodes[0];
4277 slot = left_path->slots[0];
4278 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
4279 left_type = btrfs_file_extent_type(eb, ei);
4281 if (left_type != BTRFS_FILE_EXTENT_REG) {
4285 left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
4286 left_len = btrfs_file_extent_num_bytes(eb, ei);
4287 left_offset = btrfs_file_extent_offset(eb, ei);
4288 left_gen = btrfs_file_extent_generation(eb, ei);
4291 * Following comments will refer to these graphics. L is the left
4292 * extents which we are checking at the moment. 1-8 are the right
4293 * extents that we iterate.
4296 * |-1-|-2a-|-3-|-4-|-5-|-6-|
4299 * |--1--|-2b-|...(same as above)
4301 * Alternative situation. Happens on files where extents got split.
4303 * |-----------7-----------|-6-|
4305 * Alternative situation. Happens on files which got larger.
4308 * Nothing follows after 8.
4311 key.objectid = ekey->objectid;
4312 key.type = BTRFS_EXTENT_DATA_KEY;
4313 key.offset = ekey->offset;
4314 ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
4323 * Handle special case where the right side has no extents at all.
4325 eb = path->nodes[0];
4326 slot = path->slots[0];
4327 btrfs_item_key_to_cpu(eb, &found_key, slot);
4328 if (found_key.objectid != key.objectid ||
4329 found_key.type != key.type) {
4330 /* If we're a hole then just pretend nothing changed */
4331 ret = (left_disknr) ? 0 : 1;
4336 * We're now on 2a, 2b or 7.
4339 while (key.offset < ekey->offset + left_len) {
4340 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
4341 right_type = btrfs_file_extent_type(eb, ei);
4342 if (right_type != BTRFS_FILE_EXTENT_REG) {
4347 right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
4348 right_len = btrfs_file_extent_num_bytes(eb, ei);
4349 right_offset = btrfs_file_extent_offset(eb, ei);
4350 right_gen = btrfs_file_extent_generation(eb, ei);
4353 * Are we at extent 8? If yes, we know the extent is changed.
4354 * This may only happen on the first iteration.
4356 if (found_key.offset + right_len <= ekey->offset) {
4357 /* If we're a hole just pretend nothing changed */
4358 ret = (left_disknr) ? 0 : 1;
4362 left_offset_fixed = left_offset;
4363 if (key.offset < ekey->offset) {
4364 /* Fix the right offset for 2a and 7. */
4365 right_offset += ekey->offset - key.offset;
4367 /* Fix the left offset for all behind 2a and 2b */
4368 left_offset_fixed += key.offset - ekey->offset;
4372 * Check if we have the same extent.
4374 if (left_disknr != right_disknr ||
4375 left_offset_fixed != right_offset ||
4376 left_gen != right_gen) {
4382 * Go to the next extent.
4384 ret = btrfs_next_item(sctx->parent_root, path);
4388 eb = path->nodes[0];
4389 slot = path->slots[0];
4390 btrfs_item_key_to_cpu(eb, &found_key, slot);
4392 if (ret || found_key.objectid != key.objectid ||
4393 found_key.type != key.type) {
4394 key.offset += right_len;
4397 if (found_key.offset != key.offset + right_len) {
4405 * We're now behind the left extent (treat as unchanged) or at the end
4406 * of the right side (treat as changed).
4408 if (key.offset >= ekey->offset + left_len)
4415 btrfs_free_path(path);
4419 static int get_last_extent(struct send_ctx *sctx, u64 offset)
4421 struct btrfs_path *path;
4422 struct btrfs_root *root = sctx->send_root;
4423 struct btrfs_file_extent_item *fi;
4424 struct btrfs_key key;
4429 path = alloc_path_for_send();
4433 sctx->cur_inode_last_extent = 0;
4435 key.objectid = sctx->cur_ino;
4436 key.type = BTRFS_EXTENT_DATA_KEY;
4437 key.offset = offset;
4438 ret = btrfs_search_slot_for_read(root, &key, path, 0, 1);
4442 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
4443 if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY)
4446 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
4447 struct btrfs_file_extent_item);
4448 type = btrfs_file_extent_type(path->nodes[0], fi);
4449 if (type == BTRFS_FILE_EXTENT_INLINE) {
4450 u64 size = btrfs_file_extent_inline_len(path->nodes[0],
4451 path->slots[0], fi);
4452 extent_end = ALIGN(key.offset + size,
4453 sctx->send_root->sectorsize);
4455 extent_end = key.offset +
4456 btrfs_file_extent_num_bytes(path->nodes[0], fi);
4458 sctx->cur_inode_last_extent = extent_end;
4460 btrfs_free_path(path);
4464 static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
4465 struct btrfs_key *key)
4467 struct btrfs_file_extent_item *fi;
4472 if (sctx->cur_ino != key->objectid || !need_send_hole(sctx))
4475 if (sctx->cur_inode_last_extent == (u64)-1) {
4476 ret = get_last_extent(sctx, key->offset - 1);
4481 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
4482 struct btrfs_file_extent_item);
4483 type = btrfs_file_extent_type(path->nodes[0], fi);
4484 if (type == BTRFS_FILE_EXTENT_INLINE) {
4485 u64 size = btrfs_file_extent_inline_len(path->nodes[0],
4486 path->slots[0], fi);
4487 extent_end = ALIGN(key->offset + size,
4488 sctx->send_root->sectorsize);
4490 extent_end = key->offset +
4491 btrfs_file_extent_num_bytes(path->nodes[0], fi);
4494 if (path->slots[0] == 0 &&
4495 sctx->cur_inode_last_extent < key->offset) {
4497 * We might have skipped entire leafs that contained only
4498 * file extent items for our current inode. These leafs have
4499 * a generation number smaller (older) than the one in the
4500 * current leaf and the leaf our last extent came from, and
4501 * are located between these 2 leafs.
4503 ret = get_last_extent(sctx, key->offset - 1);
4508 if (sctx->cur_inode_last_extent < key->offset)
4509 ret = send_hole(sctx, key->offset);
4510 sctx->cur_inode_last_extent = extent_end;
4514 static int process_extent(struct send_ctx *sctx,
4515 struct btrfs_path *path,
4516 struct btrfs_key *key)
4518 struct clone_root *found_clone = NULL;
4521 if (S_ISLNK(sctx->cur_inode_mode))
4524 if (sctx->parent_root && !sctx->cur_inode_new) {
4525 ret = is_extent_unchanged(sctx, path, key);
4533 struct btrfs_file_extent_item *ei;
4536 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4537 struct btrfs_file_extent_item);
4538 type = btrfs_file_extent_type(path->nodes[0], ei);
4539 if (type == BTRFS_FILE_EXTENT_PREALLOC ||
4540 type == BTRFS_FILE_EXTENT_REG) {
4542 * The send spec does not have a prealloc command yet,
4543 * so just leave a hole for prealloc'ed extents until
4544 * we have enough commands queued up to justify rev'ing
4547 if (type == BTRFS_FILE_EXTENT_PREALLOC) {
4552 /* Have a hole, just skip it. */
4553 if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
4560 ret = find_extent_clone(sctx, path, key->objectid, key->offset,
4561 sctx->cur_inode_size, &found_clone);
4562 if (ret != -ENOENT && ret < 0)
4565 ret = send_write_or_clone(sctx, path, key, found_clone);
4569 ret = maybe_send_hole(sctx, path, key);
4574 static int process_all_extents(struct send_ctx *sctx)
4577 struct btrfs_root *root;
4578 struct btrfs_path *path;
4579 struct btrfs_key key;
4580 struct btrfs_key found_key;
4581 struct extent_buffer *eb;
4584 root = sctx->send_root;
4585 path = alloc_path_for_send();
4589 key.objectid = sctx->cmp_key->objectid;
4590 key.type = BTRFS_EXTENT_DATA_KEY;
4592 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4597 eb = path->nodes[0];
4598 slot = path->slots[0];
4600 if (slot >= btrfs_header_nritems(eb)) {
4601 ret = btrfs_next_leaf(root, path);
4604 } else if (ret > 0) {
4611 btrfs_item_key_to_cpu(eb, &found_key, slot);
4613 if (found_key.objectid != key.objectid ||
4614 found_key.type != key.type) {
4619 ret = process_extent(sctx, path, &found_key);
4627 btrfs_free_path(path);
4631 static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
4633 int *refs_processed)
4637 if (sctx->cur_ino == 0)
4639 if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
4640 sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
4642 if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
4645 ret = process_recorded_refs(sctx, pending_move);
4649 *refs_processed = 1;
4654 static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
4665 int pending_move = 0;
4666 int refs_processed = 0;
4668 ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
4674 * We have processed the refs and thus need to advance send_progress.
4675 * Now, calls to get_cur_xxx will take the updated refs of the current
4676 * inode into account.
4678 * On the other hand, if our current inode is a directory and couldn't
4679 * be moved/renamed because its parent was renamed/moved too and it has
4680 * a higher inode number, we can only move/rename our current inode
4681 * after we moved/renamed its parent. Therefore in this case operate on
4682 * the old path (pre move/rename) of our current inode, and the
4683 * move/rename will be performed later.
4685 if (refs_processed && !pending_move)
4686 sctx->send_progress = sctx->cur_ino + 1;
4688 if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
4690 if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
4693 ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
4694 &left_mode, &left_uid, &left_gid, NULL);
4698 if (!sctx->parent_root || sctx->cur_inode_new) {
4700 if (!S_ISLNK(sctx->cur_inode_mode))
4703 ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
4704 NULL, NULL, &right_mode, &right_uid,
4709 if (left_uid != right_uid || left_gid != right_gid)
4711 if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
4715 if (S_ISREG(sctx->cur_inode_mode)) {
4716 if (need_send_hole(sctx)) {
4717 if (sctx->cur_inode_last_extent == (u64)-1) {
4718 ret = get_last_extent(sctx, (u64)-1);
4722 if (sctx->cur_inode_last_extent <
4723 sctx->cur_inode_size) {
4724 ret = send_hole(sctx, sctx->cur_inode_size);
4729 ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4730 sctx->cur_inode_size);
4736 ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4737 left_uid, left_gid);
4742 ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
4749 * If other directory inodes depended on our current directory
4750 * inode's move/rename, now do their move/rename operations.
4752 if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
4753 ret = apply_children_dir_moves(sctx);
4759 * Need to send that every time, no matter if it actually
4760 * changed between the two trees as we have done changes to
4763 sctx->send_progress = sctx->cur_ino + 1;
4764 ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
4772 static int changed_inode(struct send_ctx *sctx,
4773 enum btrfs_compare_tree_result result)
4776 struct btrfs_key *key = sctx->cmp_key;
4777 struct btrfs_inode_item *left_ii = NULL;
4778 struct btrfs_inode_item *right_ii = NULL;
4782 sctx->cur_ino = key->objectid;
4783 sctx->cur_inode_new_gen = 0;
4784 sctx->cur_inode_last_extent = (u64)-1;
4787 * Set send_progress to current inode. This will tell all get_cur_xxx
4788 * functions that the current inode's refs are not updated yet. Later,
4789 * when process_recorded_refs is finished, it is set to cur_ino + 1.
4791 sctx->send_progress = sctx->cur_ino;
4793 if (result == BTRFS_COMPARE_TREE_NEW ||
4794 result == BTRFS_COMPARE_TREE_CHANGED) {
4795 left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
4796 sctx->left_path->slots[0],
4797 struct btrfs_inode_item);
4798 left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
4801 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
4802 sctx->right_path->slots[0],
4803 struct btrfs_inode_item);
4804 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
4807 if (result == BTRFS_COMPARE_TREE_CHANGED) {
4808 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
4809 sctx->right_path->slots[0],
4810 struct btrfs_inode_item);
4812 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
4816 * The cur_ino = root dir case is special here. We can't treat
4817 * the inode as deleted+reused because it would generate a
4818 * stream that tries to delete/mkdir the root dir.
4820 if (left_gen != right_gen &&
4821 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
4822 sctx->cur_inode_new_gen = 1;
4825 if (result == BTRFS_COMPARE_TREE_NEW) {
4826 sctx->cur_inode_gen = left_gen;
4827 sctx->cur_inode_new = 1;
4828 sctx->cur_inode_deleted = 0;
4829 sctx->cur_inode_size = btrfs_inode_size(
4830 sctx->left_path->nodes[0], left_ii);
4831 sctx->cur_inode_mode = btrfs_inode_mode(
4832 sctx->left_path->nodes[0], left_ii);
4833 if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
4834 ret = send_create_inode_if_needed(sctx);
4835 } else if (result == BTRFS_COMPARE_TREE_DELETED) {
4836 sctx->cur_inode_gen = right_gen;
4837 sctx->cur_inode_new = 0;
4838 sctx->cur_inode_deleted = 1;
4839 sctx->cur_inode_size = btrfs_inode_size(
4840 sctx->right_path->nodes[0], right_ii);
4841 sctx->cur_inode_mode = btrfs_inode_mode(
4842 sctx->right_path->nodes[0], right_ii);
4843 } else if (result == BTRFS_COMPARE_TREE_CHANGED) {
4845 * We need to do some special handling in case the inode was
4846 * reported as changed with a changed generation number. This
4847 * means that the original inode was deleted and new inode
4848 * reused the same inum. So we have to treat the old inode as
4849 * deleted and the new one as new.
4851 if (sctx->cur_inode_new_gen) {
4853 * First, process the inode as if it was deleted.
4855 sctx->cur_inode_gen = right_gen;
4856 sctx->cur_inode_new = 0;
4857 sctx->cur_inode_deleted = 1;
4858 sctx->cur_inode_size = btrfs_inode_size(
4859 sctx->right_path->nodes[0], right_ii);
4860 sctx->cur_inode_mode = btrfs_inode_mode(
4861 sctx->right_path->nodes[0], right_ii);
4862 ret = process_all_refs(sctx,
4863 BTRFS_COMPARE_TREE_DELETED);
4868 * Now process the inode as if it was new.
4870 sctx->cur_inode_gen = left_gen;
4871 sctx->cur_inode_new = 1;
4872 sctx->cur_inode_deleted = 0;
4873 sctx->cur_inode_size = btrfs_inode_size(
4874 sctx->left_path->nodes[0], left_ii);
4875 sctx->cur_inode_mode = btrfs_inode_mode(
4876 sctx->left_path->nodes[0], left_ii);
4877 ret = send_create_inode_if_needed(sctx);
4881 ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
4885 * Advance send_progress now as we did not get into
4886 * process_recorded_refs_if_needed in the new_gen case.
4888 sctx->send_progress = sctx->cur_ino + 1;
4891 * Now process all extents and xattrs of the inode as if
4892 * they were all new.
4894 ret = process_all_extents(sctx);
4897 ret = process_all_new_xattrs(sctx);
4901 sctx->cur_inode_gen = left_gen;
4902 sctx->cur_inode_new = 0;
4903 sctx->cur_inode_new_gen = 0;
4904 sctx->cur_inode_deleted = 0;
4905 sctx->cur_inode_size = btrfs_inode_size(
4906 sctx->left_path->nodes[0], left_ii);
4907 sctx->cur_inode_mode = btrfs_inode_mode(
4908 sctx->left_path->nodes[0], left_ii);
4917 * We have to process new refs before deleted refs, but compare_trees gives us
4918 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
4919 * first and later process them in process_recorded_refs.
4920 * For the cur_inode_new_gen case, we skip recording completely because
4921 * changed_inode did already initiate processing of refs. The reason for this is
4922 * that in this case, compare_tree actually compares the refs of 2 different
4923 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
4924 * refs of the right tree as deleted and all refs of the left tree as new.
4926 static int changed_ref(struct send_ctx *sctx,
4927 enum btrfs_compare_tree_result result)
4931 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4933 if (!sctx->cur_inode_new_gen &&
4934 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
4935 if (result == BTRFS_COMPARE_TREE_NEW)
4936 ret = record_new_ref(sctx);
4937 else if (result == BTRFS_COMPARE_TREE_DELETED)
4938 ret = record_deleted_ref(sctx);
4939 else if (result == BTRFS_COMPARE_TREE_CHANGED)
4940 ret = record_changed_ref(sctx);
4947 * Process new/deleted/changed xattrs. We skip processing in the
4948 * cur_inode_new_gen case because changed_inode did already initiate processing
4949 * of xattrs. The reason is the same as in changed_ref
4951 static int changed_xattr(struct send_ctx *sctx,
4952 enum btrfs_compare_tree_result result)
4956 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4958 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
4959 if (result == BTRFS_COMPARE_TREE_NEW)
4960 ret = process_new_xattr(sctx);
4961 else if (result == BTRFS_COMPARE_TREE_DELETED)
4962 ret = process_deleted_xattr(sctx);
4963 else if (result == BTRFS_COMPARE_TREE_CHANGED)
4964 ret = process_changed_xattr(sctx);
4971 * Process new/deleted/changed extents. We skip processing in the
4972 * cur_inode_new_gen case because changed_inode did already initiate processing
4973 * of extents. The reason is the same as in changed_ref
4975 static int changed_extent(struct send_ctx *sctx,
4976 enum btrfs_compare_tree_result result)
4980 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
4982 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
4983 if (result != BTRFS_COMPARE_TREE_DELETED)
4984 ret = process_extent(sctx, sctx->left_path,
4991 static int dir_changed(struct send_ctx *sctx, u64 dir)
4993 u64 orig_gen, new_gen;
4996 ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
5001 ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
5006 return (orig_gen != new_gen) ? 1 : 0;
5009 static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path,
5010 struct btrfs_key *key)
5012 struct btrfs_inode_extref *extref;
5013 struct extent_buffer *leaf;
5014 u64 dirid = 0, last_dirid = 0;
5021 /* Easy case, just check this one dirid */
5022 if (key->type == BTRFS_INODE_REF_KEY) {
5023 dirid = key->offset;
5025 ret = dir_changed(sctx, dirid);
5029 leaf = path->nodes[0];
5030 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
5031 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
5032 while (cur_offset < item_size) {
5033 extref = (struct btrfs_inode_extref *)(ptr +
5035 dirid = btrfs_inode_extref_parent(leaf, extref);
5036 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
5037 cur_offset += ref_name_len + sizeof(*extref);
5038 if (dirid == last_dirid)
5040 ret = dir_changed(sctx, dirid);
5050 * Updates compare related fields in sctx and simply forwards to the actual
5051 * changed_xxx functions.
5053 static int changed_cb(struct btrfs_root *left_root,
5054 struct btrfs_root *right_root,
5055 struct btrfs_path *left_path,
5056 struct btrfs_path *right_path,
5057 struct btrfs_key *key,
5058 enum btrfs_compare_tree_result result,
5062 struct send_ctx *sctx = ctx;
5064 if (result == BTRFS_COMPARE_TREE_SAME) {
5065 if (key->type == BTRFS_INODE_REF_KEY ||
5066 key->type == BTRFS_INODE_EXTREF_KEY) {
5067 ret = compare_refs(sctx, left_path, key);
5072 } else if (key->type == BTRFS_EXTENT_DATA_KEY) {
5073 return maybe_send_hole(sctx, left_path, key);
5077 result = BTRFS_COMPARE_TREE_CHANGED;
5081 sctx->left_path = left_path;
5082 sctx->right_path = right_path;
5083 sctx->cmp_key = key;
5085 ret = finish_inode_if_needed(sctx, 0);
5089 /* Ignore non-FS objects */
5090 if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
5091 key->objectid == BTRFS_FREE_SPACE_OBJECTID)
5094 if (key->type == BTRFS_INODE_ITEM_KEY)
5095 ret = changed_inode(sctx, result);
5096 else if (key->type == BTRFS_INODE_REF_KEY ||
5097 key->type == BTRFS_INODE_EXTREF_KEY)
5098 ret = changed_ref(sctx, result);
5099 else if (key->type == BTRFS_XATTR_ITEM_KEY)
5100 ret = changed_xattr(sctx, result);
5101 else if (key->type == BTRFS_EXTENT_DATA_KEY)
5102 ret = changed_extent(sctx, result);
5108 static int full_send_tree(struct send_ctx *sctx)
5111 struct btrfs_root *send_root = sctx->send_root;
5112 struct btrfs_key key;
5113 struct btrfs_key found_key;
5114 struct btrfs_path *path;
5115 struct extent_buffer *eb;
5120 path = alloc_path_for_send();
5124 spin_lock(&send_root->root_item_lock);
5125 start_ctransid = btrfs_root_ctransid(&send_root->root_item);
5126 spin_unlock(&send_root->root_item_lock);
5128 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
5129 key.type = BTRFS_INODE_ITEM_KEY;
5133 * Make sure the tree has not changed after re-joining. We detect this
5134 * by comparing start_ctransid and ctransid. They should always match.
5136 spin_lock(&send_root->root_item_lock);
5137 ctransid = btrfs_root_ctransid(&send_root->root_item);
5138 spin_unlock(&send_root->root_item_lock);
5140 if (ctransid != start_ctransid) {
5141 WARN(1, KERN_WARNING "BTRFS: the root that you're trying to "
5142 "send was modified in between. This is "
5143 "probably a bug.\n");
5148 ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
5155 eb = path->nodes[0];
5156 slot = path->slots[0];
5157 btrfs_item_key_to_cpu(eb, &found_key, slot);
5159 ret = changed_cb(send_root, NULL, path, NULL,
5160 &found_key, BTRFS_COMPARE_TREE_NEW, sctx);
5164 key.objectid = found_key.objectid;
5165 key.type = found_key.type;
5166 key.offset = found_key.offset + 1;
5168 ret = btrfs_next_item(send_root, path);
5178 ret = finish_inode_if_needed(sctx, 1);
5181 btrfs_free_path(path);
5185 static int send_subvol(struct send_ctx *sctx)
5189 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
5190 ret = send_header(sctx);
5195 ret = send_subvol_begin(sctx);
5199 if (sctx->parent_root) {
5200 ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
5204 ret = finish_inode_if_needed(sctx, 1);
5208 ret = full_send_tree(sctx);
5214 free_recorded_refs(sctx);
5218 static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
5220 spin_lock(&root->root_item_lock);
5221 root->send_in_progress--;
5223 * Not much left to do, we don't know why it's unbalanced and
5224 * can't blindly reset it to 0.
5226 if (root->send_in_progress < 0)
5227 btrfs_err(root->fs_info,
5228 "send_in_progres unbalanced %d root %llu\n",
5229 root->send_in_progress, root->root_key.objectid);
5230 spin_unlock(&root->root_item_lock);
5233 long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
5236 struct btrfs_root *send_root;
5237 struct btrfs_root *clone_root;
5238 struct btrfs_fs_info *fs_info;
5239 struct btrfs_ioctl_send_args *arg = NULL;
5240 struct btrfs_key key;
5241 struct send_ctx *sctx = NULL;
5243 u64 *clone_sources_tmp = NULL;
5244 int clone_sources_to_rollback = 0;
5245 int sort_clone_roots = 0;
5248 if (!capable(CAP_SYS_ADMIN))
5251 send_root = BTRFS_I(file_inode(mnt_file))->root;
5252 fs_info = send_root->fs_info;
5255 * The subvolume must remain read-only during send, protect against
5258 spin_lock(&send_root->root_item_lock);
5259 send_root->send_in_progress++;
5260 spin_unlock(&send_root->root_item_lock);
5263 * This is done when we lookup the root, it should already be complete
5264 * by the time we get here.
5266 WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE);
5269 * Userspace tools do the checks and warn the user if it's
5272 if (!btrfs_root_readonly(send_root)) {
5277 arg = memdup_user(arg_, sizeof(*arg));
5284 if (!access_ok(VERIFY_READ, arg->clone_sources,
5285 sizeof(*arg->clone_sources) *
5286 arg->clone_sources_count)) {
5291 if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
5296 sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
5302 INIT_LIST_HEAD(&sctx->new_refs);
5303 INIT_LIST_HEAD(&sctx->deleted_refs);
5304 INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
5305 INIT_LIST_HEAD(&sctx->name_cache_list);
5307 sctx->flags = arg->flags;
5309 sctx->send_filp = fget(arg->send_fd);
5310 if (!sctx->send_filp) {
5315 sctx->send_root = send_root;
5316 sctx->clone_roots_cnt = arg->clone_sources_count;
5318 sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
5319 sctx->send_buf = vmalloc(sctx->send_max_size);
5320 if (!sctx->send_buf) {
5325 sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE);
5326 if (!sctx->read_buf) {
5331 sctx->pending_dir_moves = RB_ROOT;
5332 sctx->waiting_dir_moves = RB_ROOT;
5334 sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
5335 (arg->clone_sources_count + 1));
5336 if (!sctx->clone_roots) {
5341 if (arg->clone_sources_count) {
5342 clone_sources_tmp = vmalloc(arg->clone_sources_count *
5343 sizeof(*arg->clone_sources));
5344 if (!clone_sources_tmp) {
5349 ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
5350 arg->clone_sources_count *
5351 sizeof(*arg->clone_sources));
5357 for (i = 0; i < arg->clone_sources_count; i++) {
5358 key.objectid = clone_sources_tmp[i];
5359 key.type = BTRFS_ROOT_ITEM_KEY;
5360 key.offset = (u64)-1;
5362 index = srcu_read_lock(&fs_info->subvol_srcu);
5364 clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
5365 if (IS_ERR(clone_root)) {
5366 srcu_read_unlock(&fs_info->subvol_srcu, index);
5367 ret = PTR_ERR(clone_root);
5370 clone_sources_to_rollback = i + 1;
5371 spin_lock(&clone_root->root_item_lock);
5372 clone_root->send_in_progress++;
5373 if (!btrfs_root_readonly(clone_root)) {
5374 spin_unlock(&clone_root->root_item_lock);
5375 srcu_read_unlock(&fs_info->subvol_srcu, index);
5379 spin_unlock(&clone_root->root_item_lock);
5380 srcu_read_unlock(&fs_info->subvol_srcu, index);
5382 sctx->clone_roots[i].root = clone_root;
5384 vfree(clone_sources_tmp);
5385 clone_sources_tmp = NULL;
5388 if (arg->parent_root) {
5389 key.objectid = arg->parent_root;
5390 key.type = BTRFS_ROOT_ITEM_KEY;
5391 key.offset = (u64)-1;
5393 index = srcu_read_lock(&fs_info->subvol_srcu);
5395 sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
5396 if (IS_ERR(sctx->parent_root)) {
5397 srcu_read_unlock(&fs_info->subvol_srcu, index);
5398 ret = PTR_ERR(sctx->parent_root);
5402 spin_lock(&sctx->parent_root->root_item_lock);
5403 sctx->parent_root->send_in_progress++;
5404 if (!btrfs_root_readonly(sctx->parent_root)) {
5405 spin_unlock(&sctx->parent_root->root_item_lock);
5406 srcu_read_unlock(&fs_info->subvol_srcu, index);
5410 spin_unlock(&sctx->parent_root->root_item_lock);
5412 srcu_read_unlock(&fs_info->subvol_srcu, index);
5416 * Clones from send_root are allowed, but only if the clone source
5417 * is behind the current send position. This is checked while searching
5418 * for possible clone sources.
5420 sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;
5422 /* We do a bsearch later */
5423 sort(sctx->clone_roots, sctx->clone_roots_cnt,
5424 sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
5426 sort_clone_roots = 1;
5428 ret = send_subvol(sctx);
5432 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) {
5433 ret = begin_cmd(sctx, BTRFS_SEND_C_END);
5436 ret = send_cmd(sctx);
5442 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
5443 while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
5445 struct pending_dir_move *pm;
5447 n = rb_first(&sctx->pending_dir_moves);
5448 pm = rb_entry(n, struct pending_dir_move, node);
5449 while (!list_empty(&pm->list)) {
5450 struct pending_dir_move *pm2;
5452 pm2 = list_first_entry(&pm->list,
5453 struct pending_dir_move, list);
5454 free_pending_move(sctx, pm2);
5456 free_pending_move(sctx, pm);
5459 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
5460 while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
5462 struct waiting_dir_move *dm;
5464 n = rb_first(&sctx->waiting_dir_moves);
5465 dm = rb_entry(n, struct waiting_dir_move, node);
5466 rb_erase(&dm->node, &sctx->waiting_dir_moves);
5470 if (sort_clone_roots) {
5471 for (i = 0; i < sctx->clone_roots_cnt; i++)
5472 btrfs_root_dec_send_in_progress(
5473 sctx->clone_roots[i].root);
5475 for (i = 0; sctx && i < clone_sources_to_rollback; i++)
5476 btrfs_root_dec_send_in_progress(
5477 sctx->clone_roots[i].root);
5479 btrfs_root_dec_send_in_progress(send_root);
5481 if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
5482 btrfs_root_dec_send_in_progress(sctx->parent_root);
5485 vfree(clone_sources_tmp);
5488 if (sctx->send_filp)
5489 fput(sctx->send_filp);
5491 vfree(sctx->clone_roots);
5492 vfree(sctx->send_buf);
5493 vfree(sctx->read_buf);
5495 name_cache_free(sctx);