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.
56 unsigned short buf_len:15;
57 unsigned short reversed:1;
61 * Average path length does not exceed 200 bytes, we'll have
62 * better packing in the slab and higher chance to satisfy
63 * a allocation later during send.
68 #define FS_PATH_INLINE_SIZE \
69 (sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
72 /* reused for each extent */
74 struct btrfs_root *root;
81 #define SEND_CTX_MAX_NAME_CACHE_SIZE 128
82 #define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
85 struct file *send_filp;
91 u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
92 u64 flags; /* 'flags' member of btrfs_ioctl_send_args is u64 */
94 struct btrfs_root *send_root;
95 struct btrfs_root *parent_root;
96 struct clone_root *clone_roots;
99 /* current state of the compare_tree call */
100 struct btrfs_path *left_path;
101 struct btrfs_path *right_path;
102 struct btrfs_key *cmp_key;
105 * infos of the currently processed inode. In case of deleted inodes,
106 * these are the values from the deleted inode.
111 int cur_inode_new_gen;
112 int cur_inode_deleted;
116 u64 cur_inode_last_extent;
120 struct list_head new_refs;
121 struct list_head deleted_refs;
123 struct radix_tree_root name_cache;
124 struct list_head name_cache_list;
127 struct file_ra_state ra;
132 * We process inodes by their increasing order, so if before an
133 * incremental send we reverse the parent/child relationship of
134 * directories such that a directory with a lower inode number was
135 * the parent of a directory with a higher inode number, and the one
136 * becoming the new parent got renamed too, we can't rename/move the
137 * directory with lower inode number when we finish processing it - we
138 * must process the directory with higher inode number first, then
139 * rename/move it and then rename/move the directory with lower inode
140 * number. Example follows.
142 * Tree state when the first send was performed:
154 * Tree state when the second (incremental) send is performed:
163 * The sequence of steps that lead to the second state was:
165 * mv /a/b/c/d /a/b/c2/d2
166 * mv /a/b/c /a/b/c2/d2/cc
168 * "c" has lower inode number, but we can't move it (2nd mv operation)
169 * before we move "d", which has higher inode number.
171 * So we just memorize which move/rename operations must be performed
172 * later when their respective parent is processed and moved/renamed.
175 /* Indexed by parent directory inode number. */
176 struct rb_root pending_dir_moves;
179 * Reverse index, indexed by the inode number of a directory that
180 * is waiting for the move/rename of its immediate parent before its
181 * own move/rename can be performed.
183 struct rb_root waiting_dir_moves;
186 * A directory that is going to be rm'ed might have a child directory
187 * which is in the pending directory moves index above. In this case,
188 * the directory can only be removed after the move/rename of its child
189 * is performed. Example:
209 * Sequence of steps that lead to the send snapshot:
210 * rm -f /a/b/c/foo.txt
212 * mv /a/b/c/x /a/b/YY
215 * When the child is processed, its move/rename is delayed until its
216 * parent is processed (as explained above), but all other operations
217 * like update utimes, chown, chgrp, etc, are performed and the paths
218 * that it uses for those operations must use the orphanized name of
219 * its parent (the directory we're going to rm later), so we need to
220 * memorize that name.
222 * Indexed by the inode number of the directory to be deleted.
224 struct rb_root orphan_dirs;
227 struct pending_dir_move {
229 struct list_head list;
233 struct list_head update_refs;
236 struct waiting_dir_move {
240 * There might be some directory that could not be removed because it
241 * was waiting for this directory inode to be moved first. Therefore
242 * after this directory is moved, we can try to rmdir the ino rmdir_ino.
247 struct orphan_dir_info {
253 struct name_cache_entry {
254 struct list_head list;
256 * radix_tree has only 32bit entries but we need to handle 64bit inums.
257 * We use the lower 32bit of the 64bit inum to store it in the tree. If
258 * more then one inum would fall into the same entry, we use radix_list
259 * to store the additional entries. radix_list is also used to store
260 * entries where two entries have the same inum but different
263 struct list_head radix_list;
269 int need_later_update;
274 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);
276 static struct waiting_dir_move *
277 get_waiting_dir_move(struct send_ctx *sctx, u64 ino);
279 static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino);
281 static int need_send_hole(struct send_ctx *sctx)
283 return (sctx->parent_root && !sctx->cur_inode_new &&
284 !sctx->cur_inode_new_gen && !sctx->cur_inode_deleted &&
285 S_ISREG(sctx->cur_inode_mode));
288 static void fs_path_reset(struct fs_path *p)
291 p->start = p->buf + p->buf_len - 1;
301 static struct fs_path *fs_path_alloc(void)
305 p = kmalloc(sizeof(*p), GFP_NOFS);
309 p->buf = p->inline_buf;
310 p->buf_len = FS_PATH_INLINE_SIZE;
315 static struct fs_path *fs_path_alloc_reversed(void)
327 static void fs_path_free(struct fs_path *p)
331 if (p->buf != p->inline_buf)
336 static int fs_path_len(struct fs_path *p)
338 return p->end - p->start;
341 static int fs_path_ensure_buf(struct fs_path *p, int len)
349 if (p->buf_len >= len)
352 if (len > PATH_MAX) {
357 path_len = p->end - p->start;
358 old_buf_len = p->buf_len;
361 * First time the inline_buf does not suffice
363 if (p->buf == p->inline_buf)
364 tmp_buf = kmalloc(len, GFP_NOFS);
366 tmp_buf = krealloc(p->buf, len, GFP_NOFS);
371 * The real size of the buffer is bigger, this will let the fast path
372 * happen most of the time
374 p->buf_len = ksize(p->buf);
377 tmp_buf = p->buf + old_buf_len - path_len - 1;
378 p->end = p->buf + p->buf_len - 1;
379 p->start = p->end - path_len;
380 memmove(p->start, tmp_buf, path_len + 1);
383 p->end = p->start + path_len;
388 static int fs_path_prepare_for_add(struct fs_path *p, int name_len,
394 new_len = p->end - p->start + name_len;
395 if (p->start != p->end)
397 ret = fs_path_ensure_buf(p, new_len);
402 if (p->start != p->end)
404 p->start -= name_len;
405 *prepared = p->start;
407 if (p->start != p->end)
418 static int fs_path_add(struct fs_path *p, const char *name, int name_len)
423 ret = fs_path_prepare_for_add(p, name_len, &prepared);
426 memcpy(prepared, name, name_len);
432 static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
437 ret = fs_path_prepare_for_add(p, p2->end - p2->start, &prepared);
440 memcpy(prepared, p2->start, p2->end - p2->start);
446 static int fs_path_add_from_extent_buffer(struct fs_path *p,
447 struct extent_buffer *eb,
448 unsigned long off, int len)
453 ret = fs_path_prepare_for_add(p, len, &prepared);
457 read_extent_buffer(eb, prepared, off, len);
463 static int fs_path_copy(struct fs_path *p, struct fs_path *from)
467 p->reversed = from->reversed;
470 ret = fs_path_add_path(p, from);
476 static void fs_path_unreverse(struct fs_path *p)
485 len = p->end - p->start;
487 p->end = p->start + len;
488 memmove(p->start, tmp, len + 1);
492 static struct btrfs_path *alloc_path_for_send(void)
494 struct btrfs_path *path;
496 path = btrfs_alloc_path();
499 path->search_commit_root = 1;
500 path->skip_locking = 1;
501 path->need_commit_sem = 1;
505 static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
515 ret = vfs_write(filp, (char *)buf + pos, len - pos, off);
516 /* TODO handle that correctly */
517 /*if (ret == -ERESTARTSYS) {
536 static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
538 struct btrfs_tlv_header *hdr;
539 int total_len = sizeof(*hdr) + len;
540 int left = sctx->send_max_size - sctx->send_size;
542 if (unlikely(left < total_len))
545 hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
546 hdr->tlv_type = cpu_to_le16(attr);
547 hdr->tlv_len = cpu_to_le16(len);
548 memcpy(hdr + 1, data, len);
549 sctx->send_size += total_len;
554 #define TLV_PUT_DEFINE_INT(bits) \
555 static int tlv_put_u##bits(struct send_ctx *sctx, \
556 u##bits attr, u##bits value) \
558 __le##bits __tmp = cpu_to_le##bits(value); \
559 return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \
562 TLV_PUT_DEFINE_INT(64)
564 static int tlv_put_string(struct send_ctx *sctx, u16 attr,
565 const char *str, int len)
569 return tlv_put(sctx, attr, str, len);
572 static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
575 return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
578 static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
579 struct extent_buffer *eb,
580 struct btrfs_timespec *ts)
582 struct btrfs_timespec bts;
583 read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
584 return tlv_put(sctx, attr, &bts, sizeof(bts));
588 #define TLV_PUT(sctx, attrtype, attrlen, data) \
590 ret = tlv_put(sctx, attrtype, attrlen, data); \
592 goto tlv_put_failure; \
595 #define TLV_PUT_INT(sctx, attrtype, bits, value) \
597 ret = tlv_put_u##bits(sctx, attrtype, value); \
599 goto tlv_put_failure; \
602 #define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
603 #define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
604 #define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
605 #define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
606 #define TLV_PUT_STRING(sctx, attrtype, str, len) \
608 ret = tlv_put_string(sctx, attrtype, str, len); \
610 goto tlv_put_failure; \
612 #define TLV_PUT_PATH(sctx, attrtype, p) \
614 ret = tlv_put_string(sctx, attrtype, p->start, \
615 p->end - p->start); \
617 goto tlv_put_failure; \
619 #define TLV_PUT_UUID(sctx, attrtype, uuid) \
621 ret = tlv_put_uuid(sctx, attrtype, uuid); \
623 goto tlv_put_failure; \
625 #define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
627 ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
629 goto tlv_put_failure; \
632 static int send_header(struct send_ctx *sctx)
634 struct btrfs_stream_header hdr;
636 strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
637 hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
639 return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
644 * For each command/item we want to send to userspace, we call this function.
646 static int begin_cmd(struct send_ctx *sctx, int cmd)
648 struct btrfs_cmd_header *hdr;
650 if (WARN_ON(!sctx->send_buf))
653 BUG_ON(sctx->send_size);
655 sctx->send_size += sizeof(*hdr);
656 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
657 hdr->cmd = cpu_to_le16(cmd);
662 static int send_cmd(struct send_ctx *sctx)
665 struct btrfs_cmd_header *hdr;
668 hdr = (struct btrfs_cmd_header *)sctx->send_buf;
669 hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
672 crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
673 hdr->crc = cpu_to_le32(crc);
675 ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
678 sctx->total_send_size += sctx->send_size;
679 sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
686 * Sends a move instruction to user space
688 static int send_rename(struct send_ctx *sctx,
689 struct fs_path *from, struct fs_path *to)
693 verbose_printk("btrfs: send_rename %s -> %s\n", from->start, to->start);
695 ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
699 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
700 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
702 ret = send_cmd(sctx);
710 * Sends a link instruction to user space
712 static int send_link(struct send_ctx *sctx,
713 struct fs_path *path, struct fs_path *lnk)
717 verbose_printk("btrfs: send_link %s -> %s\n", path->start, lnk->start);
719 ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
723 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
724 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
726 ret = send_cmd(sctx);
734 * Sends an unlink instruction to user space
736 static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
740 verbose_printk("btrfs: send_unlink %s\n", path->start);
742 ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
746 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
748 ret = send_cmd(sctx);
756 * Sends a rmdir instruction to user space
758 static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
762 verbose_printk("btrfs: send_rmdir %s\n", path->start);
764 ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
768 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
770 ret = send_cmd(sctx);
778 * Helper function to retrieve some fields from an inode item.
780 static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
781 u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid,
785 struct btrfs_inode_item *ii;
786 struct btrfs_key key;
789 key.type = BTRFS_INODE_ITEM_KEY;
791 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
798 ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
799 struct btrfs_inode_item);
801 *size = btrfs_inode_size(path->nodes[0], ii);
803 *gen = btrfs_inode_generation(path->nodes[0], ii);
805 *mode = btrfs_inode_mode(path->nodes[0], ii);
807 *uid = btrfs_inode_uid(path->nodes[0], ii);
809 *gid = btrfs_inode_gid(path->nodes[0], ii);
811 *rdev = btrfs_inode_rdev(path->nodes[0], ii);
816 static int get_inode_info(struct btrfs_root *root,
817 u64 ino, u64 *size, u64 *gen,
818 u64 *mode, u64 *uid, u64 *gid,
821 struct btrfs_path *path;
824 path = alloc_path_for_send();
827 ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid,
829 btrfs_free_path(path);
833 typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
838 * Helper function to iterate the entries in ONE btrfs_inode_ref or
839 * btrfs_inode_extref.
840 * The iterate callback may return a non zero value to stop iteration. This can
841 * be a negative value for error codes or 1 to simply stop it.
843 * path must point to the INODE_REF or INODE_EXTREF when called.
845 static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
846 struct btrfs_key *found_key, int resolve,
847 iterate_inode_ref_t iterate, void *ctx)
849 struct extent_buffer *eb = path->nodes[0];
850 struct btrfs_item *item;
851 struct btrfs_inode_ref *iref;
852 struct btrfs_inode_extref *extref;
853 struct btrfs_path *tmp_path;
857 int slot = path->slots[0];
864 unsigned long name_off;
865 unsigned long elem_size;
868 p = fs_path_alloc_reversed();
872 tmp_path = alloc_path_for_send();
879 if (found_key->type == BTRFS_INODE_REF_KEY) {
880 ptr = (unsigned long)btrfs_item_ptr(eb, slot,
881 struct btrfs_inode_ref);
882 item = btrfs_item_nr(slot);
883 total = btrfs_item_size(eb, item);
884 elem_size = sizeof(*iref);
886 ptr = btrfs_item_ptr_offset(eb, slot);
887 total = btrfs_item_size_nr(eb, slot);
888 elem_size = sizeof(*extref);
891 while (cur < total) {
894 if (found_key->type == BTRFS_INODE_REF_KEY) {
895 iref = (struct btrfs_inode_ref *)(ptr + cur);
896 name_len = btrfs_inode_ref_name_len(eb, iref);
897 name_off = (unsigned long)(iref + 1);
898 index = btrfs_inode_ref_index(eb, iref);
899 dir = found_key->offset;
901 extref = (struct btrfs_inode_extref *)(ptr + cur);
902 name_len = btrfs_inode_extref_name_len(eb, extref);
903 name_off = (unsigned long)&extref->name;
904 index = btrfs_inode_extref_index(eb, extref);
905 dir = btrfs_inode_extref_parent(eb, extref);
909 start = btrfs_ref_to_path(root, tmp_path, name_len,
913 ret = PTR_ERR(start);
916 if (start < p->buf) {
917 /* overflow , try again with larger buffer */
918 ret = fs_path_ensure_buf(p,
919 p->buf_len + p->buf - start);
922 start = btrfs_ref_to_path(root, tmp_path,
927 ret = PTR_ERR(start);
930 BUG_ON(start < p->buf);
934 ret = fs_path_add_from_extent_buffer(p, eb, name_off,
940 cur += elem_size + name_len;
941 ret = iterate(num, dir, index, p, ctx);
948 btrfs_free_path(tmp_path);
953 typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
954 const char *name, int name_len,
955 const char *data, int data_len,
959 * Helper function to iterate the entries in ONE btrfs_dir_item.
960 * The iterate callback may return a non zero value to stop iteration. This can
961 * be a negative value for error codes or 1 to simply stop it.
963 * path must point to the dir item when called.
965 static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
966 struct btrfs_key *found_key,
967 iterate_dir_item_t iterate, void *ctx)
970 struct extent_buffer *eb;
971 struct btrfs_item *item;
972 struct btrfs_dir_item *di;
973 struct btrfs_key di_key;
975 const int buf_len = PATH_MAX;
985 buf = kmalloc(buf_len, GFP_NOFS);
992 slot = path->slots[0];
993 item = btrfs_item_nr(slot);
994 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
997 total = btrfs_item_size(eb, item);
1000 while (cur < total) {
1001 name_len = btrfs_dir_name_len(eb, di);
1002 data_len = btrfs_dir_data_len(eb, di);
1003 type = btrfs_dir_type(eb, di);
1004 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
1009 if (name_len + data_len > buf_len) {
1010 ret = -ENAMETOOLONG;
1014 read_extent_buffer(eb, buf, (unsigned long)(di + 1),
1015 name_len + data_len);
1017 len = sizeof(*di) + name_len + data_len;
1018 di = (struct btrfs_dir_item *)((char *)di + len);
1021 ret = iterate(num, &di_key, buf, name_len, buf + name_len,
1022 data_len, type, ctx);
1038 static int __copy_first_ref(int num, u64 dir, int index,
1039 struct fs_path *p, void *ctx)
1042 struct fs_path *pt = ctx;
1044 ret = fs_path_copy(pt, p);
1048 /* we want the first only */
1053 * Retrieve the first path of an inode. If an inode has more then one
1054 * ref/hardlink, this is ignored.
1056 static int get_inode_path(struct btrfs_root *root,
1057 u64 ino, struct fs_path *path)
1060 struct btrfs_key key, found_key;
1061 struct btrfs_path *p;
1063 p = alloc_path_for_send();
1067 fs_path_reset(path);
1070 key.type = BTRFS_INODE_REF_KEY;
1073 ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
1080 btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
1081 if (found_key.objectid != ino ||
1082 (found_key.type != BTRFS_INODE_REF_KEY &&
1083 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1088 ret = iterate_inode_ref(root, p, &found_key, 1,
1089 __copy_first_ref, path);
1099 struct backref_ctx {
1100 struct send_ctx *sctx;
1102 struct btrfs_path *path;
1103 /* number of total found references */
1107 * used for clones found in send_root. clones found behind cur_objectid
1108 * and cur_offset are not considered as allowed clones.
1113 /* may be truncated in case it's the last extent in a file */
1116 /* Just to check for bugs in backref resolving */
1120 static int __clone_root_cmp_bsearch(const void *key, const void *elt)
1122 u64 root = (u64)(uintptr_t)key;
1123 struct clone_root *cr = (struct clone_root *)elt;
1125 if (root < cr->root->objectid)
1127 if (root > cr->root->objectid)
1132 static int __clone_root_cmp_sort(const void *e1, const void *e2)
1134 struct clone_root *cr1 = (struct clone_root *)e1;
1135 struct clone_root *cr2 = (struct clone_root *)e2;
1137 if (cr1->root->objectid < cr2->root->objectid)
1139 if (cr1->root->objectid > cr2->root->objectid)
1145 * Called for every backref that is found for the current extent.
1146 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1148 static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
1150 struct backref_ctx *bctx = ctx_;
1151 struct clone_root *found;
1155 /* First check if the root is in the list of accepted clone sources */
1156 found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1157 bctx->sctx->clone_roots_cnt,
1158 sizeof(struct clone_root),
1159 __clone_root_cmp_bsearch);
1163 if (found->root == bctx->sctx->send_root &&
1164 ino == bctx->cur_objectid &&
1165 offset == bctx->cur_offset) {
1166 bctx->found_itself = 1;
1170 * There are inodes that have extents that lie behind its i_size. Don't
1171 * accept clones from these extents.
1173 ret = __get_inode_info(found->root, bctx->path, ino, &i_size, NULL, NULL,
1175 btrfs_release_path(bctx->path);
1179 if (offset + bctx->extent_len > i_size)
1183 * Make sure we don't consider clones from send_root that are
1184 * behind the current inode/offset.
1186 if (found->root == bctx->sctx->send_root) {
1188 * TODO for the moment we don't accept clones from the inode
1189 * that is currently send. We may change this when
1190 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1193 if (ino >= bctx->cur_objectid)
1196 if (ino > bctx->cur_objectid)
1198 if (offset + bctx->extent_len > bctx->cur_offset)
1204 found->found_refs++;
1205 if (ino < found->ino) {
1207 found->offset = offset;
1208 } else if (found->ino == ino) {
1210 * same extent found more then once in the same file.
1212 if (found->offset > offset + bctx->extent_len)
1213 found->offset = offset;
1220 * Given an inode, offset and extent item, it finds a good clone for a clone
1221 * instruction. Returns -ENOENT when none could be found. The function makes
1222 * sure that the returned clone is usable at the point where sending is at the
1223 * moment. This means, that no clones are accepted which lie behind the current
1226 * path must point to the extent item when called.
1228 static int find_extent_clone(struct send_ctx *sctx,
1229 struct btrfs_path *path,
1230 u64 ino, u64 data_offset,
1232 struct clone_root **found)
1239 u64 extent_item_pos;
1241 struct btrfs_file_extent_item *fi;
1242 struct extent_buffer *eb = path->nodes[0];
1243 struct backref_ctx *backref_ctx = NULL;
1244 struct clone_root *cur_clone_root;
1245 struct btrfs_key found_key;
1246 struct btrfs_path *tmp_path;
1250 tmp_path = alloc_path_for_send();
1254 /* We only use this path under the commit sem */
1255 tmp_path->need_commit_sem = 0;
1257 backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
1263 backref_ctx->path = tmp_path;
1265 if (data_offset >= ino_size) {
1267 * There may be extents that lie behind the file's size.
1268 * I at least had this in combination with snapshotting while
1269 * writing large files.
1275 fi = btrfs_item_ptr(eb, path->slots[0],
1276 struct btrfs_file_extent_item);
1277 extent_type = btrfs_file_extent_type(eb, fi);
1278 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1282 compressed = btrfs_file_extent_compression(eb, fi);
1284 num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1285 disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
1286 if (disk_byte == 0) {
1290 logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1292 down_read(&sctx->send_root->fs_info->commit_root_sem);
1293 ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path,
1294 &found_key, &flags);
1295 up_read(&sctx->send_root->fs_info->commit_root_sem);
1296 btrfs_release_path(tmp_path);
1300 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1306 * Setup the clone roots.
1308 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1309 cur_clone_root = sctx->clone_roots + i;
1310 cur_clone_root->ino = (u64)-1;
1311 cur_clone_root->offset = 0;
1312 cur_clone_root->found_refs = 0;
1315 backref_ctx->sctx = sctx;
1316 backref_ctx->found = 0;
1317 backref_ctx->cur_objectid = ino;
1318 backref_ctx->cur_offset = data_offset;
1319 backref_ctx->found_itself = 0;
1320 backref_ctx->extent_len = num_bytes;
1323 * The last extent of a file may be too large due to page alignment.
1324 * We need to adjust extent_len in this case so that the checks in
1325 * __iterate_backrefs work.
1327 if (data_offset + num_bytes >= ino_size)
1328 backref_ctx->extent_len = ino_size - data_offset;
1331 * Now collect all backrefs.
1333 if (compressed == BTRFS_COMPRESS_NONE)
1334 extent_item_pos = logical - found_key.objectid;
1336 extent_item_pos = 0;
1337 ret = iterate_extent_inodes(sctx->send_root->fs_info,
1338 found_key.objectid, extent_item_pos, 1,
1339 __iterate_backrefs, backref_ctx);
1344 if (!backref_ctx->found_itself) {
1345 /* found a bug in backref code? */
1347 btrfs_err(sctx->send_root->fs_info, "did not find backref in "
1348 "send_root. inode=%llu, offset=%llu, "
1349 "disk_byte=%llu found extent=%llu\n",
1350 ino, data_offset, disk_byte, found_key.objectid);
1354 verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "
1356 "num_bytes=%llu, logical=%llu\n",
1357 data_offset, ino, num_bytes, logical);
1359 if (!backref_ctx->found)
1360 verbose_printk("btrfs: no clones found\n");
1362 cur_clone_root = NULL;
1363 for (i = 0; i < sctx->clone_roots_cnt; i++) {
1364 if (sctx->clone_roots[i].found_refs) {
1365 if (!cur_clone_root)
1366 cur_clone_root = sctx->clone_roots + i;
1367 else if (sctx->clone_roots[i].root == sctx->send_root)
1368 /* prefer clones from send_root over others */
1369 cur_clone_root = sctx->clone_roots + i;
1374 if (cur_clone_root) {
1375 if (compressed != BTRFS_COMPRESS_NONE) {
1377 * Offsets given by iterate_extent_inodes() are relative
1378 * to the start of the extent, we need to add logical
1379 * offset from the file extent item.
1380 * (See why at backref.c:check_extent_in_eb())
1382 cur_clone_root->offset += btrfs_file_extent_offset(eb,
1385 *found = cur_clone_root;
1392 btrfs_free_path(tmp_path);
1397 static int read_symlink(struct btrfs_root *root,
1399 struct fs_path *dest)
1402 struct btrfs_path *path;
1403 struct btrfs_key key;
1404 struct btrfs_file_extent_item *ei;
1410 path = alloc_path_for_send();
1415 key.type = BTRFS_EXTENT_DATA_KEY;
1417 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1422 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
1423 struct btrfs_file_extent_item);
1424 type = btrfs_file_extent_type(path->nodes[0], ei);
1425 compression = btrfs_file_extent_compression(path->nodes[0], ei);
1426 BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
1427 BUG_ON(compression);
1429 off = btrfs_file_extent_inline_start(ei);
1430 len = btrfs_file_extent_inline_len(path->nodes[0], path->slots[0], ei);
1432 ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
1435 btrfs_free_path(path);
1440 * Helper function to generate a file name that is unique in the root of
1441 * send_root and parent_root. This is used to generate names for orphan inodes.
1443 static int gen_unique_name(struct send_ctx *sctx,
1445 struct fs_path *dest)
1448 struct btrfs_path *path;
1449 struct btrfs_dir_item *di;
1454 path = alloc_path_for_send();
1459 len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
1461 ASSERT(len < sizeof(tmp));
1463 di = btrfs_lookup_dir_item(NULL, sctx->send_root,
1464 path, BTRFS_FIRST_FREE_OBJECTID,
1465 tmp, strlen(tmp), 0);
1466 btrfs_release_path(path);
1472 /* not unique, try again */
1477 if (!sctx->parent_root) {
1483 di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
1484 path, BTRFS_FIRST_FREE_OBJECTID,
1485 tmp, strlen(tmp), 0);
1486 btrfs_release_path(path);
1492 /* not unique, try again */
1500 ret = fs_path_add(dest, tmp, strlen(tmp));
1503 btrfs_free_path(path);
1508 inode_state_no_change,
1509 inode_state_will_create,
1510 inode_state_did_create,
1511 inode_state_will_delete,
1512 inode_state_did_delete,
1515 static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
1523 ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1525 if (ret < 0 && ret != -ENOENT)
1529 if (!sctx->parent_root) {
1530 right_ret = -ENOENT;
1532 ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1533 NULL, NULL, NULL, NULL);
1534 if (ret < 0 && ret != -ENOENT)
1539 if (!left_ret && !right_ret) {
1540 if (left_gen == gen && right_gen == gen) {
1541 ret = inode_state_no_change;
1542 } else if (left_gen == gen) {
1543 if (ino < sctx->send_progress)
1544 ret = inode_state_did_create;
1546 ret = inode_state_will_create;
1547 } else if (right_gen == gen) {
1548 if (ino < sctx->send_progress)
1549 ret = inode_state_did_delete;
1551 ret = inode_state_will_delete;
1555 } else if (!left_ret) {
1556 if (left_gen == gen) {
1557 if (ino < sctx->send_progress)
1558 ret = inode_state_did_create;
1560 ret = inode_state_will_create;
1564 } else if (!right_ret) {
1565 if (right_gen == gen) {
1566 if (ino < sctx->send_progress)
1567 ret = inode_state_did_delete;
1569 ret = inode_state_will_delete;
1581 static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
1585 ret = get_cur_inode_state(sctx, ino, gen);
1589 if (ret == inode_state_no_change ||
1590 ret == inode_state_did_create ||
1591 ret == inode_state_will_delete)
1601 * Helper function to lookup a dir item in a dir.
1603 static int lookup_dir_item_inode(struct btrfs_root *root,
1604 u64 dir, const char *name, int name_len,
1609 struct btrfs_dir_item *di;
1610 struct btrfs_key key;
1611 struct btrfs_path *path;
1613 path = alloc_path_for_send();
1617 di = btrfs_lookup_dir_item(NULL, root, path,
1618 dir, name, name_len, 0);
1627 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1628 *found_inode = key.objectid;
1629 *found_type = btrfs_dir_type(path->nodes[0], di);
1632 btrfs_free_path(path);
1637 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
1638 * generation of the parent dir and the name of the dir entry.
1640 static int get_first_ref(struct btrfs_root *root, u64 ino,
1641 u64 *dir, u64 *dir_gen, struct fs_path *name)
1644 struct btrfs_key key;
1645 struct btrfs_key found_key;
1646 struct btrfs_path *path;
1650 path = alloc_path_for_send();
1655 key.type = BTRFS_INODE_REF_KEY;
1658 ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
1662 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1664 if (ret || found_key.objectid != ino ||
1665 (found_key.type != BTRFS_INODE_REF_KEY &&
1666 found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1671 if (found_key.type == BTRFS_INODE_REF_KEY) {
1672 struct btrfs_inode_ref *iref;
1673 iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1674 struct btrfs_inode_ref);
1675 len = btrfs_inode_ref_name_len(path->nodes[0], iref);
1676 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1677 (unsigned long)(iref + 1),
1679 parent_dir = found_key.offset;
1681 struct btrfs_inode_extref *extref;
1682 extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1683 struct btrfs_inode_extref);
1684 len = btrfs_inode_extref_name_len(path->nodes[0], extref);
1685 ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1686 (unsigned long)&extref->name, len);
1687 parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
1691 btrfs_release_path(path);
1693 ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
1701 btrfs_free_path(path);
1705 static int is_first_ref(struct btrfs_root *root,
1707 const char *name, int name_len)
1710 struct fs_path *tmp_name;
1714 tmp_name = fs_path_alloc();
1718 ret = get_first_ref(root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
1722 if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1727 ret = !memcmp(tmp_name->start, name, name_len);
1730 fs_path_free(tmp_name);
1735 * Used by process_recorded_refs to determine if a new ref would overwrite an
1736 * already existing ref. In case it detects an overwrite, it returns the
1737 * inode/gen in who_ino/who_gen.
1738 * When an overwrite is detected, process_recorded_refs does proper orphanizing
1739 * to make sure later references to the overwritten inode are possible.
1740 * Orphanizing is however only required for the first ref of an inode.
1741 * process_recorded_refs does an additional is_first_ref check to see if
1742 * orphanizing is really required.
1744 static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
1745 const char *name, int name_len,
1746 u64 *who_ino, u64 *who_gen)
1750 u64 other_inode = 0;
1753 if (!sctx->parent_root)
1756 ret = is_inode_existent(sctx, dir, dir_gen);
1761 * If we have a parent root we need to verify that the parent dir was
1762 * not delted and then re-created, if it was then we have no overwrite
1763 * and we can just unlink this entry.
1765 if (sctx->parent_root) {
1766 ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
1768 if (ret < 0 && ret != -ENOENT)
1778 ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
1779 &other_inode, &other_type);
1780 if (ret < 0 && ret != -ENOENT)
1788 * Check if the overwritten ref was already processed. If yes, the ref
1789 * was already unlinked/moved, so we can safely assume that we will not
1790 * overwrite anything at this point in time.
1792 if (other_inode > sctx->send_progress) {
1793 ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1794 who_gen, NULL, NULL, NULL, NULL);
1799 *who_ino = other_inode;
1809 * Checks if the ref was overwritten by an already processed inode. This is
1810 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
1811 * thus the orphan name needs be used.
1812 * process_recorded_refs also uses it to avoid unlinking of refs that were
1815 static int did_overwrite_ref(struct send_ctx *sctx,
1816 u64 dir, u64 dir_gen,
1817 u64 ino, u64 ino_gen,
1818 const char *name, int name_len)
1825 if (!sctx->parent_root)
1828 ret = is_inode_existent(sctx, dir, dir_gen);
1832 /* check if the ref was overwritten by another ref */
1833 ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
1834 &ow_inode, &other_type);
1835 if (ret < 0 && ret != -ENOENT)
1838 /* was never and will never be overwritten */
1843 ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1848 if (ow_inode == ino && gen == ino_gen) {
1853 /* we know that it is or will be overwritten. check this now */
1854 if (ow_inode < sctx->send_progress)
1864 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
1865 * that got overwritten. This is used by process_recorded_refs to determine
1866 * if it has to use the path as returned by get_cur_path or the orphan name.
1868 static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
1871 struct fs_path *name = NULL;
1875 if (!sctx->parent_root)
1878 name = fs_path_alloc();
1882 ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
1886 ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
1887 name->start, fs_path_len(name));
1895 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
1896 * so we need to do some special handling in case we have clashes. This function
1897 * takes care of this with the help of name_cache_entry::radix_list.
1898 * In case of error, nce is kfreed.
1900 static int name_cache_insert(struct send_ctx *sctx,
1901 struct name_cache_entry *nce)
1904 struct list_head *nce_head;
1906 nce_head = radix_tree_lookup(&sctx->name_cache,
1907 (unsigned long)nce->ino);
1909 nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
1914 INIT_LIST_HEAD(nce_head);
1916 ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
1923 list_add_tail(&nce->radix_list, nce_head);
1924 list_add_tail(&nce->list, &sctx->name_cache_list);
1925 sctx->name_cache_size++;
1930 static void name_cache_delete(struct send_ctx *sctx,
1931 struct name_cache_entry *nce)
1933 struct list_head *nce_head;
1935 nce_head = radix_tree_lookup(&sctx->name_cache,
1936 (unsigned long)nce->ino);
1938 btrfs_err(sctx->send_root->fs_info,
1939 "name_cache_delete lookup failed ino %llu cache size %d, leaking memory",
1940 nce->ino, sctx->name_cache_size);
1943 list_del(&nce->radix_list);
1944 list_del(&nce->list);
1945 sctx->name_cache_size--;
1948 * We may not get to the final release of nce_head if the lookup fails
1950 if (nce_head && list_empty(nce_head)) {
1951 radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
1956 static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
1959 struct list_head *nce_head;
1960 struct name_cache_entry *cur;
1962 nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
1966 list_for_each_entry(cur, nce_head, radix_list) {
1967 if (cur->ino == ino && cur->gen == gen)
1974 * Removes the entry from the list and adds it back to the end. This marks the
1975 * entry as recently used so that name_cache_clean_unused does not remove it.
1977 static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
1979 list_del(&nce->list);
1980 list_add_tail(&nce->list, &sctx->name_cache_list);
1984 * Remove some entries from the beginning of name_cache_list.
1986 static void name_cache_clean_unused(struct send_ctx *sctx)
1988 struct name_cache_entry *nce;
1990 if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
1993 while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
1994 nce = list_entry(sctx->name_cache_list.next,
1995 struct name_cache_entry, list);
1996 name_cache_delete(sctx, nce);
2001 static void name_cache_free(struct send_ctx *sctx)
2003 struct name_cache_entry *nce;
2005 while (!list_empty(&sctx->name_cache_list)) {
2006 nce = list_entry(sctx->name_cache_list.next,
2007 struct name_cache_entry, list);
2008 name_cache_delete(sctx, nce);
2014 * Used by get_cur_path for each ref up to the root.
2015 * Returns 0 if it succeeded.
2016 * Returns 1 if the inode is not existent or got overwritten. In that case, the
2017 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
2018 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
2019 * Returns <0 in case of error.
2021 static int __get_cur_name_and_parent(struct send_ctx *sctx,
2025 struct fs_path *dest)
2029 struct btrfs_path *path = NULL;
2030 struct name_cache_entry *nce = NULL;
2033 * First check if we already did a call to this function with the same
2034 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
2035 * return the cached result.
2037 nce = name_cache_search(sctx, ino, gen);
2039 if (ino < sctx->send_progress && nce->need_later_update) {
2040 name_cache_delete(sctx, nce);
2044 name_cache_used(sctx, nce);
2045 *parent_ino = nce->parent_ino;
2046 *parent_gen = nce->parent_gen;
2047 ret = fs_path_add(dest, nce->name, nce->name_len);
2055 path = alloc_path_for_send();
2060 * If the inode is not existent yet, add the orphan name and return 1.
2061 * This should only happen for the parent dir that we determine in
2064 ret = is_inode_existent(sctx, ino, gen);
2069 ret = gen_unique_name(sctx, ino, gen, dest);
2077 * Depending on whether the inode was already processed or not, use
2078 * send_root or parent_root for ref lookup.
2080 if (ino < sctx->send_progress)
2081 ret = get_first_ref(sctx->send_root, ino,
2082 parent_ino, parent_gen, dest);
2084 ret = get_first_ref(sctx->parent_root, ino,
2085 parent_ino, parent_gen, dest);
2090 * Check if the ref was overwritten by an inode's ref that was processed
2091 * earlier. If yes, treat as orphan and return 1.
2093 ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
2094 dest->start, dest->end - dest->start);
2098 fs_path_reset(dest);
2099 ret = gen_unique_name(sctx, ino, gen, dest);
2107 * Store the result of the lookup in the name cache.
2109 nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS);
2117 nce->parent_ino = *parent_ino;
2118 nce->parent_gen = *parent_gen;
2119 nce->name_len = fs_path_len(dest);
2121 strcpy(nce->name, dest->start);
2123 if (ino < sctx->send_progress)
2124 nce->need_later_update = 0;
2126 nce->need_later_update = 1;
2128 nce_ret = name_cache_insert(sctx, nce);
2131 name_cache_clean_unused(sctx);
2134 btrfs_free_path(path);
2139 * Magic happens here. This function returns the first ref to an inode as it
2140 * would look like while receiving the stream at this point in time.
2141 * We walk the path up to the root. For every inode in between, we check if it
2142 * was already processed/sent. If yes, we continue with the parent as found
2143 * in send_root. If not, we continue with the parent as found in parent_root.
2144 * If we encounter an inode that was deleted at this point in time, we use the
2145 * inodes "orphan" name instead of the real name and stop. Same with new inodes
2146 * that were not created yet and overwritten inodes/refs.
2148 * When do we have have orphan inodes:
2149 * 1. When an inode is freshly created and thus no valid refs are available yet
2150 * 2. When a directory lost all it's refs (deleted) but still has dir items
2151 * inside which were not processed yet (pending for move/delete). If anyone
2152 * tried to get the path to the dir items, it would get a path inside that
2154 * 3. When an inode is moved around or gets new links, it may overwrite the ref
2155 * of an unprocessed inode. If in that case the first ref would be
2156 * overwritten, the overwritten inode gets "orphanized". Later when we
2157 * process this overwritten inode, it is restored at a new place by moving
2160 * sctx->send_progress tells this function at which point in time receiving
2163 static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
2164 struct fs_path *dest)
2167 struct fs_path *name = NULL;
2168 u64 parent_inode = 0;
2172 name = fs_path_alloc();
2179 fs_path_reset(dest);
2181 while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
2182 fs_path_reset(name);
2184 if (is_waiting_for_rm(sctx, ino)) {
2185 ret = gen_unique_name(sctx, ino, gen, name);
2188 ret = fs_path_add_path(dest, name);
2192 if (is_waiting_for_move(sctx, ino)) {
2193 ret = get_first_ref(sctx->parent_root, ino,
2194 &parent_inode, &parent_gen, name);
2196 ret = __get_cur_name_and_parent(sctx, ino, gen,
2206 ret = fs_path_add_path(dest, name);
2217 fs_path_unreverse(dest);
2222 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2224 static int send_subvol_begin(struct send_ctx *sctx)
2227 struct btrfs_root *send_root = sctx->send_root;
2228 struct btrfs_root *parent_root = sctx->parent_root;
2229 struct btrfs_path *path;
2230 struct btrfs_key key;
2231 struct btrfs_root_ref *ref;
2232 struct extent_buffer *leaf;
2236 path = btrfs_alloc_path();
2240 name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS);
2242 btrfs_free_path(path);
2246 key.objectid = send_root->objectid;
2247 key.type = BTRFS_ROOT_BACKREF_KEY;
2250 ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
2259 leaf = path->nodes[0];
2260 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2261 if (key.type != BTRFS_ROOT_BACKREF_KEY ||
2262 key.objectid != send_root->objectid) {
2266 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
2267 namelen = btrfs_root_ref_name_len(leaf, ref);
2268 read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
2269 btrfs_release_path(path);
2272 ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
2276 ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
2281 TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
2282 TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2283 sctx->send_root->root_item.uuid);
2284 TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2285 le64_to_cpu(sctx->send_root->root_item.ctransid));
2287 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2288 sctx->parent_root->root_item.uuid);
2289 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2290 le64_to_cpu(sctx->parent_root->root_item.ctransid));
2293 ret = send_cmd(sctx);
2297 btrfs_free_path(path);
2302 static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
2307 verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino, size);
2309 p = fs_path_alloc();
2313 ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
2317 ret = get_cur_path(sctx, ino, gen, p);
2320 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2321 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
2323 ret = send_cmd(sctx);
2331 static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
2336 verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino, mode);
2338 p = fs_path_alloc();
2342 ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
2346 ret = get_cur_path(sctx, ino, gen, p);
2349 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2350 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
2352 ret = send_cmd(sctx);
2360 static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
2365 verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino, uid, gid);
2367 p = fs_path_alloc();
2371 ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
2375 ret = get_cur_path(sctx, ino, gen, p);
2378 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2379 TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
2380 TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
2382 ret = send_cmd(sctx);
2390 static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
2393 struct fs_path *p = NULL;
2394 struct btrfs_inode_item *ii;
2395 struct btrfs_path *path = NULL;
2396 struct extent_buffer *eb;
2397 struct btrfs_key key;
2400 verbose_printk("btrfs: send_utimes %llu\n", ino);
2402 p = fs_path_alloc();
2406 path = alloc_path_for_send();
2413 key.type = BTRFS_INODE_ITEM_KEY;
2415 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2419 eb = path->nodes[0];
2420 slot = path->slots[0];
2421 ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2423 ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
2427 ret = get_cur_path(sctx, ino, gen, p);
2430 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2431 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb,
2432 btrfs_inode_atime(ii));
2433 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb,
2434 btrfs_inode_mtime(ii));
2435 TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb,
2436 btrfs_inode_ctime(ii));
2437 /* TODO Add otime support when the otime patches get into upstream */
2439 ret = send_cmd(sctx);
2444 btrfs_free_path(path);
2449 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2450 * a valid path yet because we did not process the refs yet. So, the inode
2451 * is created as orphan.
2453 static int send_create_inode(struct send_ctx *sctx, u64 ino)
2462 verbose_printk("btrfs: send_create_inode %llu\n", ino);
2464 p = fs_path_alloc();
2468 if (ino != sctx->cur_ino) {
2469 ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode,
2474 gen = sctx->cur_inode_gen;
2475 mode = sctx->cur_inode_mode;
2476 rdev = sctx->cur_inode_rdev;
2479 if (S_ISREG(mode)) {
2480 cmd = BTRFS_SEND_C_MKFILE;
2481 } else if (S_ISDIR(mode)) {
2482 cmd = BTRFS_SEND_C_MKDIR;
2483 } else if (S_ISLNK(mode)) {
2484 cmd = BTRFS_SEND_C_SYMLINK;
2485 } else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2486 cmd = BTRFS_SEND_C_MKNOD;
2487 } else if (S_ISFIFO(mode)) {
2488 cmd = BTRFS_SEND_C_MKFIFO;
2489 } else if (S_ISSOCK(mode)) {
2490 cmd = BTRFS_SEND_C_MKSOCK;
2492 printk(KERN_WARNING "btrfs: unexpected inode type %o",
2493 (int)(mode & S_IFMT));
2498 ret = begin_cmd(sctx, cmd);
2502 ret = gen_unique_name(sctx, ino, gen, p);
2506 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2507 TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2509 if (S_ISLNK(mode)) {
2511 ret = read_symlink(sctx->send_root, ino, p);
2514 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
2515 } else if (S_ISCHR(mode) || S_ISBLK(mode) ||
2516 S_ISFIFO(mode) || S_ISSOCK(mode)) {
2517 TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
2518 TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2521 ret = send_cmd(sctx);
2533 * We need some special handling for inodes that get processed before the parent
2534 * directory got created. See process_recorded_refs for details.
2535 * This function does the check if we already created the dir out of order.
2537 static int did_create_dir(struct send_ctx *sctx, u64 dir)
2540 struct btrfs_path *path = NULL;
2541 struct btrfs_key key;
2542 struct btrfs_key found_key;
2543 struct btrfs_key di_key;
2544 struct extent_buffer *eb;
2545 struct btrfs_dir_item *di;
2548 path = alloc_path_for_send();
2555 key.type = BTRFS_DIR_INDEX_KEY;
2557 ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2562 eb = path->nodes[0];
2563 slot = path->slots[0];
2564 if (slot >= btrfs_header_nritems(eb)) {
2565 ret = btrfs_next_leaf(sctx->send_root, path);
2568 } else if (ret > 0) {
2575 btrfs_item_key_to_cpu(eb, &found_key, slot);
2576 if (found_key.objectid != key.objectid ||
2577 found_key.type != key.type) {
2582 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2583 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2585 if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
2586 di_key.objectid < sctx->send_progress) {
2595 btrfs_free_path(path);
2600 * Only creates the inode if it is:
2601 * 1. Not a directory
2602 * 2. Or a directory which was not created already due to out of order
2603 * directories. See did_create_dir and process_recorded_refs for details.
2605 static int send_create_inode_if_needed(struct send_ctx *sctx)
2609 if (S_ISDIR(sctx->cur_inode_mode)) {
2610 ret = did_create_dir(sctx, sctx->cur_ino);
2619 ret = send_create_inode(sctx, sctx->cur_ino);
2627 struct recorded_ref {
2628 struct list_head list;
2631 struct fs_path *full_path;
2639 * We need to process new refs before deleted refs, but compare_tree gives us
2640 * everything mixed. So we first record all refs and later process them.
2641 * This function is a helper to record one ref.
2643 static int __record_ref(struct list_head *head, u64 dir,
2644 u64 dir_gen, struct fs_path *path)
2646 struct recorded_ref *ref;
2648 ref = kmalloc(sizeof(*ref), GFP_NOFS);
2653 ref->dir_gen = dir_gen;
2654 ref->full_path = path;
2656 ref->name = (char *)kbasename(ref->full_path->start);
2657 ref->name_len = ref->full_path->end - ref->name;
2658 ref->dir_path = ref->full_path->start;
2659 if (ref->name == ref->full_path->start)
2660 ref->dir_path_len = 0;
2662 ref->dir_path_len = ref->full_path->end -
2663 ref->full_path->start - 1 - ref->name_len;
2665 list_add_tail(&ref->list, head);
2669 static int dup_ref(struct recorded_ref *ref, struct list_head *list)
2671 struct recorded_ref *new;
2673 new = kmalloc(sizeof(*ref), GFP_NOFS);
2677 new->dir = ref->dir;
2678 new->dir_gen = ref->dir_gen;
2679 new->full_path = NULL;
2680 INIT_LIST_HEAD(&new->list);
2681 list_add_tail(&new->list, list);
2685 static void __free_recorded_refs(struct list_head *head)
2687 struct recorded_ref *cur;
2689 while (!list_empty(head)) {
2690 cur = list_entry(head->next, struct recorded_ref, list);
2691 fs_path_free(cur->full_path);
2692 list_del(&cur->list);
2697 static void free_recorded_refs(struct send_ctx *sctx)
2699 __free_recorded_refs(&sctx->new_refs);
2700 __free_recorded_refs(&sctx->deleted_refs);
2704 * Renames/moves a file/dir to its orphan name. Used when the first
2705 * ref of an unprocessed inode gets overwritten and for all non empty
2708 static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
2709 struct fs_path *path)
2712 struct fs_path *orphan;
2714 orphan = fs_path_alloc();
2718 ret = gen_unique_name(sctx, ino, gen, orphan);
2722 ret = send_rename(sctx, path, orphan);
2725 fs_path_free(orphan);
2729 static struct orphan_dir_info *
2730 add_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2732 struct rb_node **p = &sctx->orphan_dirs.rb_node;
2733 struct rb_node *parent = NULL;
2734 struct orphan_dir_info *entry, *odi;
2736 odi = kmalloc(sizeof(*odi), GFP_NOFS);
2738 return ERR_PTR(-ENOMEM);
2744 entry = rb_entry(parent, struct orphan_dir_info, node);
2745 if (dir_ino < entry->ino) {
2747 } else if (dir_ino > entry->ino) {
2748 p = &(*p)->rb_right;
2755 rb_link_node(&odi->node, parent, p);
2756 rb_insert_color(&odi->node, &sctx->orphan_dirs);
2760 static struct orphan_dir_info *
2761 get_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2763 struct rb_node *n = sctx->orphan_dirs.rb_node;
2764 struct orphan_dir_info *entry;
2767 entry = rb_entry(n, struct orphan_dir_info, node);
2768 if (dir_ino < entry->ino)
2770 else if (dir_ino > entry->ino)
2778 static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino)
2780 struct orphan_dir_info *odi = get_orphan_dir_info(sctx, dir_ino);
2785 static void free_orphan_dir_info(struct send_ctx *sctx,
2786 struct orphan_dir_info *odi)
2790 rb_erase(&odi->node, &sctx->orphan_dirs);
2795 * Returns 1 if a directory can be removed at this point in time.
2796 * We check this by iterating all dir items and checking if the inode behind
2797 * the dir item was already processed.
2799 static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
2803 struct btrfs_root *root = sctx->parent_root;
2804 struct btrfs_path *path;
2805 struct btrfs_key key;
2806 struct btrfs_key found_key;
2807 struct btrfs_key loc;
2808 struct btrfs_dir_item *di;
2811 * Don't try to rmdir the top/root subvolume dir.
2813 if (dir == BTRFS_FIRST_FREE_OBJECTID)
2816 path = alloc_path_for_send();
2821 key.type = BTRFS_DIR_INDEX_KEY;
2823 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2828 struct waiting_dir_move *dm;
2830 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2831 ret = btrfs_next_leaf(root, path);
2838 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2840 if (found_key.objectid != key.objectid ||
2841 found_key.type != key.type)
2844 di = btrfs_item_ptr(path->nodes[0], path->slots[0],
2845 struct btrfs_dir_item);
2846 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
2848 dm = get_waiting_dir_move(sctx, loc.objectid);
2850 struct orphan_dir_info *odi;
2852 odi = add_orphan_dir_info(sctx, dir);
2858 dm->rmdir_ino = dir;
2863 if (loc.objectid > send_progress) {
2874 btrfs_free_path(path);
2878 static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
2880 struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino);
2882 return entry != NULL;
2885 static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2887 struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
2888 struct rb_node *parent = NULL;
2889 struct waiting_dir_move *entry, *dm;
2891 dm = kmalloc(sizeof(*dm), GFP_NOFS);
2899 entry = rb_entry(parent, struct waiting_dir_move, node);
2900 if (ino < entry->ino) {
2902 } else if (ino > entry->ino) {
2903 p = &(*p)->rb_right;
2910 rb_link_node(&dm->node, parent, p);
2911 rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
2915 static struct waiting_dir_move *
2916 get_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2918 struct rb_node *n = sctx->waiting_dir_moves.rb_node;
2919 struct waiting_dir_move *entry;
2922 entry = rb_entry(n, struct waiting_dir_move, node);
2923 if (ino < entry->ino)
2925 else if (ino > entry->ino)
2933 static void free_waiting_dir_move(struct send_ctx *sctx,
2934 struct waiting_dir_move *dm)
2938 rb_erase(&dm->node, &sctx->waiting_dir_moves);
2942 static int add_pending_dir_move(struct send_ctx *sctx,
2947 struct rb_node **p = &sctx->pending_dir_moves.rb_node;
2948 struct rb_node *parent = NULL;
2949 struct pending_dir_move *entry = NULL, *pm;
2950 struct recorded_ref *cur;
2954 pm = kmalloc(sizeof(*pm), GFP_NOFS);
2957 pm->parent_ino = parent_ino;
2960 INIT_LIST_HEAD(&pm->list);
2961 INIT_LIST_HEAD(&pm->update_refs);
2962 RB_CLEAR_NODE(&pm->node);
2966 entry = rb_entry(parent, struct pending_dir_move, node);
2967 if (parent_ino < entry->parent_ino) {
2969 } else if (parent_ino > entry->parent_ino) {
2970 p = &(*p)->rb_right;
2977 list_for_each_entry(cur, &sctx->deleted_refs, list) {
2978 ret = dup_ref(cur, &pm->update_refs);
2982 list_for_each_entry(cur, &sctx->new_refs, list) {
2983 ret = dup_ref(cur, &pm->update_refs);
2988 ret = add_waiting_dir_move(sctx, pm->ino);
2993 list_add_tail(&pm->list, &entry->list);
2995 rb_link_node(&pm->node, parent, p);
2996 rb_insert_color(&pm->node, &sctx->pending_dir_moves);
3001 __free_recorded_refs(&pm->update_refs);
3007 static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
3010 struct rb_node *n = sctx->pending_dir_moves.rb_node;
3011 struct pending_dir_move *entry;
3014 entry = rb_entry(n, struct pending_dir_move, node);
3015 if (parent_ino < entry->parent_ino)
3017 else if (parent_ino > entry->parent_ino)
3025 static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
3027 struct fs_path *from_path = NULL;
3028 struct fs_path *to_path = NULL;
3029 struct fs_path *name = NULL;
3030 u64 orig_progress = sctx->send_progress;
3031 struct recorded_ref *cur;
3032 u64 parent_ino, parent_gen;
3033 struct waiting_dir_move *dm = NULL;
3037 name = fs_path_alloc();
3038 from_path = fs_path_alloc();
3039 if (!name || !from_path) {
3044 dm = get_waiting_dir_move(sctx, pm->ino);
3046 rmdir_ino = dm->rmdir_ino;
3047 free_waiting_dir_move(sctx, dm);
3049 ret = get_first_ref(sctx->parent_root, pm->ino,
3050 &parent_ino, &parent_gen, name);
3054 if (parent_ino == sctx->cur_ino) {
3055 /* child only renamed, not moved */
3056 ASSERT(parent_gen == sctx->cur_inode_gen);
3057 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3061 ret = fs_path_add_path(from_path, name);
3065 /* child moved and maybe renamed too */
3066 sctx->send_progress = pm->ino;
3067 ret = get_cur_path(sctx, pm->ino, pm->gen, from_path);
3075 to_path = fs_path_alloc();
3081 sctx->send_progress = sctx->cur_ino + 1;
3082 ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
3086 ret = send_rename(sctx, from_path, to_path);
3091 struct orphan_dir_info *odi;
3093 odi = get_orphan_dir_info(sctx, rmdir_ino);
3095 /* already deleted */
3098 ret = can_rmdir(sctx, rmdir_ino, odi->gen, sctx->cur_ino + 1);
3104 name = fs_path_alloc();
3109 ret = get_cur_path(sctx, rmdir_ino, odi->gen, name);
3112 ret = send_rmdir(sctx, name);
3115 free_orphan_dir_info(sctx, odi);
3119 ret = send_utimes(sctx, pm->ino, pm->gen);
3124 * After rename/move, need to update the utimes of both new parent(s)
3125 * and old parent(s).
3127 list_for_each_entry(cur, &pm->update_refs, list) {
3128 if (cur->dir == rmdir_ino)
3130 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3137 fs_path_free(from_path);
3138 fs_path_free(to_path);
3139 sctx->send_progress = orig_progress;
3144 static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
3146 if (!list_empty(&m->list))
3148 if (!RB_EMPTY_NODE(&m->node))
3149 rb_erase(&m->node, &sctx->pending_dir_moves);
3150 __free_recorded_refs(&m->update_refs);
3154 static void tail_append_pending_moves(struct pending_dir_move *moves,
3155 struct list_head *stack)
3157 if (list_empty(&moves->list)) {
3158 list_add_tail(&moves->list, stack);
3161 list_splice_init(&moves->list, &list);
3162 list_add_tail(&moves->list, stack);
3163 list_splice_tail(&list, stack);
3167 static int apply_children_dir_moves(struct send_ctx *sctx)
3169 struct pending_dir_move *pm;
3170 struct list_head stack;
3171 u64 parent_ino = sctx->cur_ino;
3174 pm = get_pending_dir_moves(sctx, parent_ino);
3178 INIT_LIST_HEAD(&stack);
3179 tail_append_pending_moves(pm, &stack);
3181 while (!list_empty(&stack)) {
3182 pm = list_first_entry(&stack, struct pending_dir_move, list);
3183 parent_ino = pm->ino;
3184 ret = apply_dir_move(sctx, pm);
3185 free_pending_move(sctx, pm);
3188 pm = get_pending_dir_moves(sctx, parent_ino);
3190 tail_append_pending_moves(pm, &stack);
3195 while (!list_empty(&stack)) {
3196 pm = list_first_entry(&stack, struct pending_dir_move, list);
3197 free_pending_move(sctx, pm);
3202 static int wait_for_parent_move(struct send_ctx *sctx,
3203 struct recorded_ref *parent_ref)
3206 u64 ino = parent_ref->dir;
3207 u64 parent_ino_before, parent_ino_after;
3209 struct fs_path *path_before = NULL;
3210 struct fs_path *path_after = NULL;
3212 int register_upper_dirs;
3215 if (is_waiting_for_move(sctx, ino))
3218 if (parent_ref->dir <= sctx->cur_ino)
3221 ret = get_inode_info(sctx->parent_root, ino, NULL, &old_gen,
3222 NULL, NULL, NULL, NULL);
3228 if (parent_ref->dir_gen != old_gen)
3231 path_before = fs_path_alloc();
3235 ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
3237 if (ret == -ENOENT) {
3240 } else if (ret < 0) {
3244 path_after = fs_path_alloc();
3250 ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3252 if (ret == -ENOENT) {
3255 } else if (ret < 0) {
3259 len1 = fs_path_len(path_before);
3260 len2 = fs_path_len(path_after);
3261 if (parent_ino_before != parent_ino_after || len1 != len2 ||
3262 memcmp(path_before->start, path_after->start, len1)) {
3269 * Ok, our new most direct ancestor has a higher inode number but
3270 * wasn't moved/renamed. So maybe some of the new ancestors higher in
3271 * the hierarchy have an higher inode number too *and* were renamed
3272 * or moved - in this case we need to wait for the ancestor's rename
3273 * or move operation before we can do the move/rename for the current
3276 register_upper_dirs = 0;
3277 ino = parent_ino_after;
3279 while ((ret == 0 || register_upper_dirs) && ino > sctx->cur_ino) {
3282 fs_path_reset(path_before);
3283 fs_path_reset(path_after);
3285 ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3286 &parent_gen, path_after);
3289 ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
3291 if (ret == -ENOENT) {
3294 } else if (ret < 0) {
3298 len1 = fs_path_len(path_before);
3299 len2 = fs_path_len(path_after);
3300 if (parent_ino_before != parent_ino_after || len1 != len2 ||
3301 memcmp(path_before->start, path_after->start, len1)) {
3303 if (register_upper_dirs) {
3306 register_upper_dirs = 1;
3307 ino = parent_ref->dir;
3308 gen = parent_ref->dir_gen;
3311 } else if (register_upper_dirs) {
3312 ret = add_pending_dir_move(sctx, ino, gen,
3314 if (ret < 0 && ret != -EEXIST)
3318 ino = parent_ino_after;
3323 fs_path_free(path_before);
3324 fs_path_free(path_after);
3330 * This does all the move/link/unlink/rmdir magic.
3332 static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
3335 struct recorded_ref *cur;
3336 struct recorded_ref *cur2;
3337 struct list_head check_dirs;
3338 struct fs_path *valid_path = NULL;
3341 int did_overwrite = 0;
3343 u64 last_dir_ino_rm = 0;
3345 verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
3348 * This should never happen as the root dir always has the same ref
3349 * which is always '..'
3351 BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
3352 INIT_LIST_HEAD(&check_dirs);
3354 valid_path = fs_path_alloc();
3361 * First, check if the first ref of the current inode was overwritten
3362 * before. If yes, we know that the current inode was already orphanized
3363 * and thus use the orphan name. If not, we can use get_cur_path to
3364 * get the path of the first ref as it would like while receiving at
3365 * this point in time.
3366 * New inodes are always orphan at the beginning, so force to use the
3367 * orphan name in this case.
3368 * The first ref is stored in valid_path and will be updated if it
3369 * gets moved around.
3371 if (!sctx->cur_inode_new) {
3372 ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
3373 sctx->cur_inode_gen);
3379 if (sctx->cur_inode_new || did_overwrite) {
3380 ret = gen_unique_name(sctx, sctx->cur_ino,
3381 sctx->cur_inode_gen, valid_path);
3386 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3392 list_for_each_entry(cur, &sctx->new_refs, list) {
3394 * We may have refs where the parent directory does not exist
3395 * yet. This happens if the parent directories inum is higher
3396 * the the current inum. To handle this case, we create the
3397 * parent directory out of order. But we need to check if this
3398 * did already happen before due to other refs in the same dir.
3400 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3403 if (ret == inode_state_will_create) {
3406 * First check if any of the current inodes refs did
3407 * already create the dir.
3409 list_for_each_entry(cur2, &sctx->new_refs, list) {
3412 if (cur2->dir == cur->dir) {
3419 * If that did not happen, check if a previous inode
3420 * did already create the dir.
3423 ret = did_create_dir(sctx, cur->dir);
3427 ret = send_create_inode(sctx, cur->dir);
3434 * Check if this new ref would overwrite the first ref of
3435 * another unprocessed inode. If yes, orphanize the
3436 * overwritten inode. If we find an overwritten ref that is
3437 * not the first ref, simply unlink it.
3439 ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3440 cur->name, cur->name_len,
3441 &ow_inode, &ow_gen);
3445 ret = is_first_ref(sctx->parent_root,
3446 ow_inode, cur->dir, cur->name,
3451 ret = orphanize_inode(sctx, ow_inode, ow_gen,
3456 ret = send_unlink(sctx, cur->full_path);
3463 * link/move the ref to the new place. If we have an orphan
3464 * inode, move it and update valid_path. If not, link or move
3465 * it depending on the inode mode.
3468 ret = send_rename(sctx, valid_path, cur->full_path);
3472 ret = fs_path_copy(valid_path, cur->full_path);
3476 if (S_ISDIR(sctx->cur_inode_mode)) {
3478 * Dirs can't be linked, so move it. For moved
3479 * dirs, we always have one new and one deleted
3480 * ref. The deleted ref is ignored later.
3482 ret = wait_for_parent_move(sctx, cur);
3486 ret = add_pending_dir_move(sctx,
3488 sctx->cur_inode_gen,
3492 ret = send_rename(sctx, valid_path,
3495 ret = fs_path_copy(valid_path,
3501 ret = send_link(sctx, cur->full_path,
3507 ret = dup_ref(cur, &check_dirs);
3512 if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
3514 * Check if we can already rmdir the directory. If not,
3515 * orphanize it. For every dir item inside that gets deleted
3516 * later, we do this check again and rmdir it then if possible.
3517 * See the use of check_dirs for more details.
3519 ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3524 ret = send_rmdir(sctx, valid_path);
3527 } else if (!is_orphan) {
3528 ret = orphanize_inode(sctx, sctx->cur_ino,
3529 sctx->cur_inode_gen, valid_path);
3535 list_for_each_entry(cur, &sctx->deleted_refs, list) {
3536 ret = dup_ref(cur, &check_dirs);
3540 } else if (S_ISDIR(sctx->cur_inode_mode) &&
3541 !list_empty(&sctx->deleted_refs)) {
3543 * We have a moved dir. Add the old parent to check_dirs
3545 cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
3547 ret = dup_ref(cur, &check_dirs);
3550 } else if (!S_ISDIR(sctx->cur_inode_mode)) {
3552 * We have a non dir inode. Go through all deleted refs and
3553 * unlink them if they were not already overwritten by other
3556 list_for_each_entry(cur, &sctx->deleted_refs, list) {
3557 ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3558 sctx->cur_ino, sctx->cur_inode_gen,
3559 cur->name, cur->name_len);
3563 ret = send_unlink(sctx, cur->full_path);
3567 ret = dup_ref(cur, &check_dirs);
3572 * If the inode is still orphan, unlink the orphan. This may
3573 * happen when a previous inode did overwrite the first ref
3574 * of this inode and no new refs were added for the current
3575 * inode. Unlinking does not mean that the inode is deleted in
3576 * all cases. There may still be links to this inode in other
3580 ret = send_unlink(sctx, valid_path);
3587 * We did collect all parent dirs where cur_inode was once located. We
3588 * now go through all these dirs and check if they are pending for
3589 * deletion and if it's finally possible to perform the rmdir now.
3590 * We also update the inode stats of the parent dirs here.
3592 list_for_each_entry(cur, &check_dirs, list) {
3594 * In case we had refs into dirs that were not processed yet,
3595 * we don't need to do the utime and rmdir logic for these dirs.
3596 * The dir will be processed later.
3598 if (cur->dir > sctx->cur_ino)
3601 ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3605 if (ret == inode_state_did_create ||
3606 ret == inode_state_no_change) {
3607 /* TODO delayed utimes */
3608 ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3611 } else if (ret == inode_state_did_delete &&
3612 cur->dir != last_dir_ino_rm) {
3613 ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
3618 ret = get_cur_path(sctx, cur->dir,
3619 cur->dir_gen, valid_path);
3622 ret = send_rmdir(sctx, valid_path);
3625 last_dir_ino_rm = cur->dir;
3633 __free_recorded_refs(&check_dirs);
3634 free_recorded_refs(sctx);
3635 fs_path_free(valid_path);
3639 static int record_ref(struct btrfs_root *root, int num, u64 dir, int index,
3640 struct fs_path *name, void *ctx, struct list_head *refs)
3643 struct send_ctx *sctx = ctx;
3647 p = fs_path_alloc();
3651 ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
3656 ret = get_cur_path(sctx, dir, gen, p);
3659 ret = fs_path_add_path(p, name);
3663 ret = __record_ref(refs, dir, gen, p);
3671 static int __record_new_ref(int num, u64 dir, int index,
3672 struct fs_path *name,
3675 struct send_ctx *sctx = ctx;
3676 return record_ref(sctx->send_root, num, dir, index, name,
3677 ctx, &sctx->new_refs);
3681 static int __record_deleted_ref(int num, u64 dir, int index,
3682 struct fs_path *name,
3685 struct send_ctx *sctx = ctx;
3686 return record_ref(sctx->parent_root, num, dir, index, name,
3687 ctx, &sctx->deleted_refs);
3690 static int record_new_ref(struct send_ctx *sctx)
3694 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3695 sctx->cmp_key, 0, __record_new_ref, sctx);
3704 static int record_deleted_ref(struct send_ctx *sctx)
3708 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3709 sctx->cmp_key, 0, __record_deleted_ref, sctx);
3718 struct find_ref_ctx {
3721 struct btrfs_root *root;
3722 struct fs_path *name;
3726 static int __find_iref(int num, u64 dir, int index,
3727 struct fs_path *name,
3730 struct find_ref_ctx *ctx = ctx_;
3734 if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
3735 strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
3737 * To avoid doing extra lookups we'll only do this if everything
3740 ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
3744 if (dir_gen != ctx->dir_gen)
3746 ctx->found_idx = num;
3752 static int find_iref(struct btrfs_root *root,
3753 struct btrfs_path *path,
3754 struct btrfs_key *key,
3755 u64 dir, u64 dir_gen, struct fs_path *name)
3758 struct find_ref_ctx ctx;
3762 ctx.dir_gen = dir_gen;
3766 ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
3770 if (ctx.found_idx == -1)
3773 return ctx.found_idx;
3776 static int __record_changed_new_ref(int num, u64 dir, int index,
3777 struct fs_path *name,
3782 struct send_ctx *sctx = ctx;
3784 ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
3789 ret = find_iref(sctx->parent_root, sctx->right_path,
3790 sctx->cmp_key, dir, dir_gen, name);
3792 ret = __record_new_ref(num, dir, index, name, sctx);
3799 static int __record_changed_deleted_ref(int num, u64 dir, int index,
3800 struct fs_path *name,
3805 struct send_ctx *sctx = ctx;
3807 ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
3812 ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
3813 dir, dir_gen, name);
3815 ret = __record_deleted_ref(num, dir, index, name, sctx);
3822 static int record_changed_ref(struct send_ctx *sctx)
3826 ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3827 sctx->cmp_key, 0, __record_changed_new_ref, sctx);
3830 ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3831 sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
3841 * Record and process all refs at once. Needed when an inode changes the
3842 * generation number, which means that it was deleted and recreated.
3844 static int process_all_refs(struct send_ctx *sctx,
3845 enum btrfs_compare_tree_result cmd)
3848 struct btrfs_root *root;
3849 struct btrfs_path *path;
3850 struct btrfs_key key;
3851 struct btrfs_key found_key;
3852 struct extent_buffer *eb;
3854 iterate_inode_ref_t cb;
3855 int pending_move = 0;
3857 path = alloc_path_for_send();
3861 if (cmd == BTRFS_COMPARE_TREE_NEW) {
3862 root = sctx->send_root;
3863 cb = __record_new_ref;
3864 } else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
3865 root = sctx->parent_root;
3866 cb = __record_deleted_ref;
3868 btrfs_err(sctx->send_root->fs_info,
3869 "Wrong command %d in process_all_refs", cmd);
3874 key.objectid = sctx->cmp_key->objectid;
3875 key.type = BTRFS_INODE_REF_KEY;
3877 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3882 eb = path->nodes[0];
3883 slot = path->slots[0];
3884 if (slot >= btrfs_header_nritems(eb)) {
3885 ret = btrfs_next_leaf(root, path);
3893 btrfs_item_key_to_cpu(eb, &found_key, slot);
3895 if (found_key.objectid != key.objectid ||
3896 (found_key.type != BTRFS_INODE_REF_KEY &&
3897 found_key.type != BTRFS_INODE_EXTREF_KEY))
3900 ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
3906 btrfs_release_path(path);
3908 ret = process_recorded_refs(sctx, &pending_move);
3909 /* Only applicable to an incremental send. */
3910 ASSERT(pending_move == 0);
3913 btrfs_free_path(path);
3917 static int send_set_xattr(struct send_ctx *sctx,
3918 struct fs_path *path,
3919 const char *name, int name_len,
3920 const char *data, int data_len)
3924 ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
3928 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3929 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3930 TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
3932 ret = send_cmd(sctx);
3939 static int send_remove_xattr(struct send_ctx *sctx,
3940 struct fs_path *path,
3941 const char *name, int name_len)
3945 ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
3949 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3950 TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3952 ret = send_cmd(sctx);
3959 static int __process_new_xattr(int num, struct btrfs_key *di_key,
3960 const char *name, int name_len,
3961 const char *data, int data_len,
3965 struct send_ctx *sctx = ctx;
3967 posix_acl_xattr_header dummy_acl;
3969 p = fs_path_alloc();
3974 * This hack is needed because empty acl's are stored as zero byte
3975 * data in xattrs. Problem with that is, that receiving these zero byte
3976 * acl's will fail later. To fix this, we send a dummy acl list that
3977 * only contains the version number and no entries.
3979 if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
3980 !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
3981 if (data_len == 0) {
3982 dummy_acl.a_version =
3983 cpu_to_le32(POSIX_ACL_XATTR_VERSION);
3984 data = (char *)&dummy_acl;
3985 data_len = sizeof(dummy_acl);
3989 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3993 ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
4000 static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
4001 const char *name, int name_len,
4002 const char *data, int data_len,
4006 struct send_ctx *sctx = ctx;
4009 p = fs_path_alloc();
4013 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4017 ret = send_remove_xattr(sctx, p, name, name_len);
4024 static int process_new_xattr(struct send_ctx *sctx)
4028 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4029 sctx->cmp_key, __process_new_xattr, sctx);
4034 static int process_deleted_xattr(struct send_ctx *sctx)
4038 ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4039 sctx->cmp_key, __process_deleted_xattr, sctx);
4044 struct find_xattr_ctx {
4052 static int __find_xattr(int num, struct btrfs_key *di_key,
4053 const char *name, int name_len,
4054 const char *data, int data_len,
4055 u8 type, void *vctx)
4057 struct find_xattr_ctx *ctx = vctx;
4059 if (name_len == ctx->name_len &&
4060 strncmp(name, ctx->name, name_len) == 0) {
4061 ctx->found_idx = num;
4062 ctx->found_data_len = data_len;
4063 ctx->found_data = kmemdup(data, data_len, GFP_NOFS);
4064 if (!ctx->found_data)
4071 static int find_xattr(struct btrfs_root *root,
4072 struct btrfs_path *path,
4073 struct btrfs_key *key,
4074 const char *name, int name_len,
4075 char **data, int *data_len)
4078 struct find_xattr_ctx ctx;
4081 ctx.name_len = name_len;
4083 ctx.found_data = NULL;
4084 ctx.found_data_len = 0;
4086 ret = iterate_dir_item(root, path, key, __find_xattr, &ctx);
4090 if (ctx.found_idx == -1)
4093 *data = ctx.found_data;
4094 *data_len = ctx.found_data_len;
4096 kfree(ctx.found_data);
4098 return ctx.found_idx;
4102 static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
4103 const char *name, int name_len,
4104 const char *data, int data_len,
4108 struct send_ctx *sctx = ctx;
4109 char *found_data = NULL;
4110 int found_data_len = 0;
4112 ret = find_xattr(sctx->parent_root, sctx->right_path,
4113 sctx->cmp_key, name, name_len, &found_data,
4115 if (ret == -ENOENT) {
4116 ret = __process_new_xattr(num, di_key, name, name_len, data,
4117 data_len, type, ctx);
4118 } else if (ret >= 0) {
4119 if (data_len != found_data_len ||
4120 memcmp(data, found_data, data_len)) {
4121 ret = __process_new_xattr(num, di_key, name, name_len,
4122 data, data_len, type, ctx);
4132 static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
4133 const char *name, int name_len,
4134 const char *data, int data_len,
4138 struct send_ctx *sctx = ctx;
4140 ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
4141 name, name_len, NULL, NULL);
4143 ret = __process_deleted_xattr(num, di_key, name, name_len, data,
4144 data_len, type, ctx);
4151 static int process_changed_xattr(struct send_ctx *sctx)
4155 ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4156 sctx->cmp_key, __process_changed_new_xattr, sctx);
4159 ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4160 sctx->cmp_key, __process_changed_deleted_xattr, sctx);
4166 static int process_all_new_xattrs(struct send_ctx *sctx)
4169 struct btrfs_root *root;
4170 struct btrfs_path *path;
4171 struct btrfs_key key;
4172 struct btrfs_key found_key;
4173 struct extent_buffer *eb;
4176 path = alloc_path_for_send();
4180 root = sctx->send_root;
4182 key.objectid = sctx->cmp_key->objectid;
4183 key.type = BTRFS_XATTR_ITEM_KEY;
4185 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4190 eb = path->nodes[0];
4191 slot = path->slots[0];
4192 if (slot >= btrfs_header_nritems(eb)) {
4193 ret = btrfs_next_leaf(root, path);
4196 } else if (ret > 0) {
4203 btrfs_item_key_to_cpu(eb, &found_key, slot);
4204 if (found_key.objectid != key.objectid ||
4205 found_key.type != key.type) {
4210 ret = iterate_dir_item(root, path, &found_key,
4211 __process_new_xattr, sctx);
4219 btrfs_free_path(path);
4223 static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
4225 struct btrfs_root *root = sctx->send_root;
4226 struct btrfs_fs_info *fs_info = root->fs_info;
4227 struct inode *inode;
4230 struct btrfs_key key;
4231 pgoff_t index = offset >> PAGE_CACHE_SHIFT;
4233 unsigned pg_offset = offset & ~PAGE_CACHE_MASK;
4236 key.objectid = sctx->cur_ino;
4237 key.type = BTRFS_INODE_ITEM_KEY;
4240 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
4242 return PTR_ERR(inode);
4244 if (offset + len > i_size_read(inode)) {
4245 if (offset > i_size_read(inode))
4248 len = offset - i_size_read(inode);
4253 last_index = (offset + len - 1) >> PAGE_CACHE_SHIFT;
4255 /* initial readahead */
4256 memset(&sctx->ra, 0, sizeof(struct file_ra_state));
4257 file_ra_state_init(&sctx->ra, inode->i_mapping);
4258 btrfs_force_ra(inode->i_mapping, &sctx->ra, NULL, index,
4259 last_index - index + 1);
4261 while (index <= last_index) {
4262 unsigned cur_len = min_t(unsigned, len,
4263 PAGE_CACHE_SIZE - pg_offset);
4264 page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4270 if (!PageUptodate(page)) {
4271 btrfs_readpage(NULL, page);
4273 if (!PageUptodate(page)) {
4275 page_cache_release(page);
4282 memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len);
4285 page_cache_release(page);
4297 * Read some bytes from the current inode/file and send a write command to
4300 static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
4304 ssize_t num_read = 0;
4306 p = fs_path_alloc();
4310 verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len);
4312 num_read = fill_read_buf(sctx, offset, len);
4313 if (num_read <= 0) {
4319 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4323 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4327 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4328 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4329 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
4331 ret = send_cmd(sctx);
4342 * Send a clone command to user space.
4344 static int send_clone(struct send_ctx *sctx,
4345 u64 offset, u32 len,
4346 struct clone_root *clone_root)
4352 verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, "
4353 "clone_inode=%llu, clone_offset=%llu\n", offset, len,
4354 clone_root->root->objectid, clone_root->ino,
4355 clone_root->offset);
4357 p = fs_path_alloc();
4361 ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
4365 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4369 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4370 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
4371 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4373 if (clone_root->root == sctx->send_root) {
4374 ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
4375 &gen, NULL, NULL, NULL, NULL);
4378 ret = get_cur_path(sctx, clone_root->ino, gen, p);
4380 ret = get_inode_path(clone_root->root, clone_root->ino, p);
4385 TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4386 clone_root->root->root_item.uuid);
4387 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
4388 le64_to_cpu(clone_root->root->root_item.ctransid));
4389 TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
4390 TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
4391 clone_root->offset);
4393 ret = send_cmd(sctx);
4402 * Send an update extent command to user space.
4404 static int send_update_extent(struct send_ctx *sctx,
4405 u64 offset, u32 len)
4410 p = fs_path_alloc();
4414 ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
4418 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4422 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4423 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4424 TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);
4426 ret = send_cmd(sctx);
4434 static int send_hole(struct send_ctx *sctx, u64 end)
4436 struct fs_path *p = NULL;
4437 u64 offset = sctx->cur_inode_last_extent;
4441 p = fs_path_alloc();
4444 ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4446 goto tlv_put_failure;
4447 memset(sctx->read_buf, 0, BTRFS_SEND_READ_SIZE);
4448 while (offset < end) {
4449 len = min_t(u64, end - offset, BTRFS_SEND_READ_SIZE);
4451 ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4454 TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4455 TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4456 TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len);
4457 ret = send_cmd(sctx);
4467 static int send_write_or_clone(struct send_ctx *sctx,
4468 struct btrfs_path *path,
4469 struct btrfs_key *key,
4470 struct clone_root *clone_root)
4473 struct btrfs_file_extent_item *ei;
4474 u64 offset = key->offset;
4479 u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
4481 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4482 struct btrfs_file_extent_item);
4483 type = btrfs_file_extent_type(path->nodes[0], ei);
4484 if (type == BTRFS_FILE_EXTENT_INLINE) {
4485 len = btrfs_file_extent_inline_len(path->nodes[0],
4486 path->slots[0], ei);
4488 * it is possible the inline item won't cover the whole page,
4489 * but there may be items after this page. Make
4490 * sure to send the whole thing
4492 len = PAGE_CACHE_ALIGN(len);
4494 len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
4497 if (offset + len > sctx->cur_inode_size)
4498 len = sctx->cur_inode_size - offset;
4504 if (clone_root && IS_ALIGNED(offset + len, bs)) {
4505 ret = send_clone(sctx, offset, len, clone_root);
4506 } else if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) {
4507 ret = send_update_extent(sctx, offset, len);
4511 if (l > BTRFS_SEND_READ_SIZE)
4512 l = BTRFS_SEND_READ_SIZE;
4513 ret = send_write(sctx, pos + offset, l);
4526 static int is_extent_unchanged(struct send_ctx *sctx,
4527 struct btrfs_path *left_path,
4528 struct btrfs_key *ekey)
4531 struct btrfs_key key;
4532 struct btrfs_path *path = NULL;
4533 struct extent_buffer *eb;
4535 struct btrfs_key found_key;
4536 struct btrfs_file_extent_item *ei;
4541 u64 left_offset_fixed;
4549 path = alloc_path_for_send();
4553 eb = left_path->nodes[0];
4554 slot = left_path->slots[0];
4555 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
4556 left_type = btrfs_file_extent_type(eb, ei);
4558 if (left_type != BTRFS_FILE_EXTENT_REG) {
4562 left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
4563 left_len = btrfs_file_extent_num_bytes(eb, ei);
4564 left_offset = btrfs_file_extent_offset(eb, ei);
4565 left_gen = btrfs_file_extent_generation(eb, ei);
4568 * Following comments will refer to these graphics. L is the left
4569 * extents which we are checking at the moment. 1-8 are the right
4570 * extents that we iterate.
4573 * |-1-|-2a-|-3-|-4-|-5-|-6-|
4576 * |--1--|-2b-|...(same as above)
4578 * Alternative situation. Happens on files where extents got split.
4580 * |-----------7-----------|-6-|
4582 * Alternative situation. Happens on files which got larger.
4585 * Nothing follows after 8.
4588 key.objectid = ekey->objectid;
4589 key.type = BTRFS_EXTENT_DATA_KEY;
4590 key.offset = ekey->offset;
4591 ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
4600 * Handle special case where the right side has no extents at all.
4602 eb = path->nodes[0];
4603 slot = path->slots[0];
4604 btrfs_item_key_to_cpu(eb, &found_key, slot);
4605 if (found_key.objectid != key.objectid ||
4606 found_key.type != key.type) {
4607 /* If we're a hole then just pretend nothing changed */
4608 ret = (left_disknr) ? 0 : 1;
4613 * We're now on 2a, 2b or 7.
4616 while (key.offset < ekey->offset + left_len) {
4617 ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
4618 right_type = btrfs_file_extent_type(eb, ei);
4619 if (right_type != BTRFS_FILE_EXTENT_REG) {
4624 right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
4625 right_len = btrfs_file_extent_num_bytes(eb, ei);
4626 right_offset = btrfs_file_extent_offset(eb, ei);
4627 right_gen = btrfs_file_extent_generation(eb, ei);
4630 * Are we at extent 8? If yes, we know the extent is changed.
4631 * This may only happen on the first iteration.
4633 if (found_key.offset + right_len <= ekey->offset) {
4634 /* If we're a hole just pretend nothing changed */
4635 ret = (left_disknr) ? 0 : 1;
4639 left_offset_fixed = left_offset;
4640 if (key.offset < ekey->offset) {
4641 /* Fix the right offset for 2a and 7. */
4642 right_offset += ekey->offset - key.offset;
4644 /* Fix the left offset for all behind 2a and 2b */
4645 left_offset_fixed += key.offset - ekey->offset;
4649 * Check if we have the same extent.
4651 if (left_disknr != right_disknr ||
4652 left_offset_fixed != right_offset ||
4653 left_gen != right_gen) {
4659 * Go to the next extent.
4661 ret = btrfs_next_item(sctx->parent_root, path);
4665 eb = path->nodes[0];
4666 slot = path->slots[0];
4667 btrfs_item_key_to_cpu(eb, &found_key, slot);
4669 if (ret || found_key.objectid != key.objectid ||
4670 found_key.type != key.type) {
4671 key.offset += right_len;
4674 if (found_key.offset != key.offset + right_len) {
4682 * We're now behind the left extent (treat as unchanged) or at the end
4683 * of the right side (treat as changed).
4685 if (key.offset >= ekey->offset + left_len)
4692 btrfs_free_path(path);
4696 static int get_last_extent(struct send_ctx *sctx, u64 offset)
4698 struct btrfs_path *path;
4699 struct btrfs_root *root = sctx->send_root;
4700 struct btrfs_file_extent_item *fi;
4701 struct btrfs_key key;
4706 path = alloc_path_for_send();
4710 sctx->cur_inode_last_extent = 0;
4712 key.objectid = sctx->cur_ino;
4713 key.type = BTRFS_EXTENT_DATA_KEY;
4714 key.offset = offset;
4715 ret = btrfs_search_slot_for_read(root, &key, path, 0, 1);
4719 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
4720 if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY)
4723 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
4724 struct btrfs_file_extent_item);
4725 type = btrfs_file_extent_type(path->nodes[0], fi);
4726 if (type == BTRFS_FILE_EXTENT_INLINE) {
4727 u64 size = btrfs_file_extent_inline_len(path->nodes[0],
4728 path->slots[0], fi);
4729 extent_end = ALIGN(key.offset + size,
4730 sctx->send_root->sectorsize);
4732 extent_end = key.offset +
4733 btrfs_file_extent_num_bytes(path->nodes[0], fi);
4735 sctx->cur_inode_last_extent = extent_end;
4737 btrfs_free_path(path);
4741 static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
4742 struct btrfs_key *key)
4744 struct btrfs_file_extent_item *fi;
4749 if (sctx->cur_ino != key->objectid || !need_send_hole(sctx))
4752 if (sctx->cur_inode_last_extent == (u64)-1) {
4753 ret = get_last_extent(sctx, key->offset - 1);
4758 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
4759 struct btrfs_file_extent_item);
4760 type = btrfs_file_extent_type(path->nodes[0], fi);
4761 if (type == BTRFS_FILE_EXTENT_INLINE) {
4762 u64 size = btrfs_file_extent_inline_len(path->nodes[0],
4763 path->slots[0], fi);
4764 extent_end = ALIGN(key->offset + size,
4765 sctx->send_root->sectorsize);
4767 extent_end = key->offset +
4768 btrfs_file_extent_num_bytes(path->nodes[0], fi);
4771 if (path->slots[0] == 0 &&
4772 sctx->cur_inode_last_extent < key->offset) {
4774 * We might have skipped entire leafs that contained only
4775 * file extent items for our current inode. These leafs have
4776 * a generation number smaller (older) than the one in the
4777 * current leaf and the leaf our last extent came from, and
4778 * are located between these 2 leafs.
4780 ret = get_last_extent(sctx, key->offset - 1);
4785 if (sctx->cur_inode_last_extent < key->offset)
4786 ret = send_hole(sctx, key->offset);
4787 sctx->cur_inode_last_extent = extent_end;
4791 static int process_extent(struct send_ctx *sctx,
4792 struct btrfs_path *path,
4793 struct btrfs_key *key)
4795 struct clone_root *found_clone = NULL;
4798 if (S_ISLNK(sctx->cur_inode_mode))
4801 if (sctx->parent_root && !sctx->cur_inode_new) {
4802 ret = is_extent_unchanged(sctx, path, key);
4810 struct btrfs_file_extent_item *ei;
4813 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4814 struct btrfs_file_extent_item);
4815 type = btrfs_file_extent_type(path->nodes[0], ei);
4816 if (type == BTRFS_FILE_EXTENT_PREALLOC ||
4817 type == BTRFS_FILE_EXTENT_REG) {
4819 * The send spec does not have a prealloc command yet,
4820 * so just leave a hole for prealloc'ed extents until
4821 * we have enough commands queued up to justify rev'ing
4824 if (type == BTRFS_FILE_EXTENT_PREALLOC) {
4829 /* Have a hole, just skip it. */
4830 if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
4837 ret = find_extent_clone(sctx, path, key->objectid, key->offset,
4838 sctx->cur_inode_size, &found_clone);
4839 if (ret != -ENOENT && ret < 0)
4842 ret = send_write_or_clone(sctx, path, key, found_clone);
4846 ret = maybe_send_hole(sctx, path, key);
4851 static int process_all_extents(struct send_ctx *sctx)
4854 struct btrfs_root *root;
4855 struct btrfs_path *path;
4856 struct btrfs_key key;
4857 struct btrfs_key found_key;
4858 struct extent_buffer *eb;
4861 root = sctx->send_root;
4862 path = alloc_path_for_send();
4866 key.objectid = sctx->cmp_key->objectid;
4867 key.type = BTRFS_EXTENT_DATA_KEY;
4869 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4874 eb = path->nodes[0];
4875 slot = path->slots[0];
4877 if (slot >= btrfs_header_nritems(eb)) {
4878 ret = btrfs_next_leaf(root, path);
4881 } else if (ret > 0) {
4888 btrfs_item_key_to_cpu(eb, &found_key, slot);
4890 if (found_key.objectid != key.objectid ||
4891 found_key.type != key.type) {
4896 ret = process_extent(sctx, path, &found_key);
4904 btrfs_free_path(path);
4908 static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
4910 int *refs_processed)
4914 if (sctx->cur_ino == 0)
4916 if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
4917 sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
4919 if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
4922 ret = process_recorded_refs(sctx, pending_move);
4926 *refs_processed = 1;
4931 static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
4942 int pending_move = 0;
4943 int refs_processed = 0;
4945 ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
4951 * We have processed the refs and thus need to advance send_progress.
4952 * Now, calls to get_cur_xxx will take the updated refs of the current
4953 * inode into account.
4955 * On the other hand, if our current inode is a directory and couldn't
4956 * be moved/renamed because its parent was renamed/moved too and it has
4957 * a higher inode number, we can only move/rename our current inode
4958 * after we moved/renamed its parent. Therefore in this case operate on
4959 * the old path (pre move/rename) of our current inode, and the
4960 * move/rename will be performed later.
4962 if (refs_processed && !pending_move)
4963 sctx->send_progress = sctx->cur_ino + 1;
4965 if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
4967 if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
4970 ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
4971 &left_mode, &left_uid, &left_gid, NULL);
4975 if (!sctx->parent_root || sctx->cur_inode_new) {
4977 if (!S_ISLNK(sctx->cur_inode_mode))
4980 ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
4981 NULL, NULL, &right_mode, &right_uid,
4986 if (left_uid != right_uid || left_gid != right_gid)
4988 if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
4992 if (S_ISREG(sctx->cur_inode_mode)) {
4993 if (need_send_hole(sctx)) {
4994 if (sctx->cur_inode_last_extent == (u64)-1 ||
4995 sctx->cur_inode_last_extent <
4996 sctx->cur_inode_size) {
4997 ret = get_last_extent(sctx, (u64)-1);
5001 if (sctx->cur_inode_last_extent <
5002 sctx->cur_inode_size) {
5003 ret = send_hole(sctx, sctx->cur_inode_size);
5008 ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5009 sctx->cur_inode_size);
5015 ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5016 left_uid, left_gid);
5021 ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5028 * If other directory inodes depended on our current directory
5029 * inode's move/rename, now do their move/rename operations.
5031 if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
5032 ret = apply_children_dir_moves(sctx);
5036 * Need to send that every time, no matter if it actually
5037 * changed between the two trees as we have done changes to
5038 * the inode before. If our inode is a directory and it's
5039 * waiting to be moved/renamed, we will send its utimes when
5040 * it's moved/renamed, therefore we don't need to do it here.
5042 sctx->send_progress = sctx->cur_ino + 1;
5043 ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
5052 static int changed_inode(struct send_ctx *sctx,
5053 enum btrfs_compare_tree_result result)
5056 struct btrfs_key *key = sctx->cmp_key;
5057 struct btrfs_inode_item *left_ii = NULL;
5058 struct btrfs_inode_item *right_ii = NULL;
5062 sctx->cur_ino = key->objectid;
5063 sctx->cur_inode_new_gen = 0;
5064 sctx->cur_inode_last_extent = (u64)-1;
5067 * Set send_progress to current inode. This will tell all get_cur_xxx
5068 * functions that the current inode's refs are not updated yet. Later,
5069 * when process_recorded_refs is finished, it is set to cur_ino + 1.
5071 sctx->send_progress = sctx->cur_ino;
5073 if (result == BTRFS_COMPARE_TREE_NEW ||
5074 result == BTRFS_COMPARE_TREE_CHANGED) {
5075 left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
5076 sctx->left_path->slots[0],
5077 struct btrfs_inode_item);
5078 left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
5081 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
5082 sctx->right_path->slots[0],
5083 struct btrfs_inode_item);
5084 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
5087 if (result == BTRFS_COMPARE_TREE_CHANGED) {
5088 right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
5089 sctx->right_path->slots[0],
5090 struct btrfs_inode_item);
5092 right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
5096 * The cur_ino = root dir case is special here. We can't treat
5097 * the inode as deleted+reused because it would generate a
5098 * stream that tries to delete/mkdir the root dir.
5100 if (left_gen != right_gen &&
5101 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5102 sctx->cur_inode_new_gen = 1;
5105 if (result == BTRFS_COMPARE_TREE_NEW) {
5106 sctx->cur_inode_gen = left_gen;
5107 sctx->cur_inode_new = 1;
5108 sctx->cur_inode_deleted = 0;
5109 sctx->cur_inode_size = btrfs_inode_size(
5110 sctx->left_path->nodes[0], left_ii);
5111 sctx->cur_inode_mode = btrfs_inode_mode(
5112 sctx->left_path->nodes[0], left_ii);
5113 sctx->cur_inode_rdev = btrfs_inode_rdev(
5114 sctx->left_path->nodes[0], left_ii);
5115 if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5116 ret = send_create_inode_if_needed(sctx);
5117 } else if (result == BTRFS_COMPARE_TREE_DELETED) {
5118 sctx->cur_inode_gen = right_gen;
5119 sctx->cur_inode_new = 0;
5120 sctx->cur_inode_deleted = 1;
5121 sctx->cur_inode_size = btrfs_inode_size(
5122 sctx->right_path->nodes[0], right_ii);
5123 sctx->cur_inode_mode = btrfs_inode_mode(
5124 sctx->right_path->nodes[0], right_ii);
5125 } else if (result == BTRFS_COMPARE_TREE_CHANGED) {
5127 * We need to do some special handling in case the inode was
5128 * reported as changed with a changed generation number. This
5129 * means that the original inode was deleted and new inode
5130 * reused the same inum. So we have to treat the old inode as
5131 * deleted and the new one as new.
5133 if (sctx->cur_inode_new_gen) {
5135 * First, process the inode as if it was deleted.
5137 sctx->cur_inode_gen = right_gen;
5138 sctx->cur_inode_new = 0;
5139 sctx->cur_inode_deleted = 1;
5140 sctx->cur_inode_size = btrfs_inode_size(
5141 sctx->right_path->nodes[0], right_ii);
5142 sctx->cur_inode_mode = btrfs_inode_mode(
5143 sctx->right_path->nodes[0], right_ii);
5144 ret = process_all_refs(sctx,
5145 BTRFS_COMPARE_TREE_DELETED);
5150 * Now process the inode as if it was new.
5152 sctx->cur_inode_gen = left_gen;
5153 sctx->cur_inode_new = 1;
5154 sctx->cur_inode_deleted = 0;
5155 sctx->cur_inode_size = btrfs_inode_size(
5156 sctx->left_path->nodes[0], left_ii);
5157 sctx->cur_inode_mode = btrfs_inode_mode(
5158 sctx->left_path->nodes[0], left_ii);
5159 sctx->cur_inode_rdev = btrfs_inode_rdev(
5160 sctx->left_path->nodes[0], left_ii);
5161 ret = send_create_inode_if_needed(sctx);
5165 ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
5169 * Advance send_progress now as we did not get into
5170 * process_recorded_refs_if_needed in the new_gen case.
5172 sctx->send_progress = sctx->cur_ino + 1;
5175 * Now process all extents and xattrs of the inode as if
5176 * they were all new.
5178 ret = process_all_extents(sctx);
5181 ret = process_all_new_xattrs(sctx);
5185 sctx->cur_inode_gen = left_gen;
5186 sctx->cur_inode_new = 0;
5187 sctx->cur_inode_new_gen = 0;
5188 sctx->cur_inode_deleted = 0;
5189 sctx->cur_inode_size = btrfs_inode_size(
5190 sctx->left_path->nodes[0], left_ii);
5191 sctx->cur_inode_mode = btrfs_inode_mode(
5192 sctx->left_path->nodes[0], left_ii);
5201 * We have to process new refs before deleted refs, but compare_trees gives us
5202 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
5203 * first and later process them in process_recorded_refs.
5204 * For the cur_inode_new_gen case, we skip recording completely because
5205 * changed_inode did already initiate processing of refs. The reason for this is
5206 * that in this case, compare_tree actually compares the refs of 2 different
5207 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
5208 * refs of the right tree as deleted and all refs of the left tree as new.
5210 static int changed_ref(struct send_ctx *sctx,
5211 enum btrfs_compare_tree_result result)
5215 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
5217 if (!sctx->cur_inode_new_gen &&
5218 sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
5219 if (result == BTRFS_COMPARE_TREE_NEW)
5220 ret = record_new_ref(sctx);
5221 else if (result == BTRFS_COMPARE_TREE_DELETED)
5222 ret = record_deleted_ref(sctx);
5223 else if (result == BTRFS_COMPARE_TREE_CHANGED)
5224 ret = record_changed_ref(sctx);
5231 * Process new/deleted/changed xattrs. We skip processing in the
5232 * cur_inode_new_gen case because changed_inode did already initiate processing
5233 * of xattrs. The reason is the same as in changed_ref
5235 static int changed_xattr(struct send_ctx *sctx,
5236 enum btrfs_compare_tree_result result)
5240 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
5242 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
5243 if (result == BTRFS_COMPARE_TREE_NEW)
5244 ret = process_new_xattr(sctx);
5245 else if (result == BTRFS_COMPARE_TREE_DELETED)
5246 ret = process_deleted_xattr(sctx);
5247 else if (result == BTRFS_COMPARE_TREE_CHANGED)
5248 ret = process_changed_xattr(sctx);
5255 * Process new/deleted/changed extents. We skip processing in the
5256 * cur_inode_new_gen case because changed_inode did already initiate processing
5257 * of extents. The reason is the same as in changed_ref
5259 static int changed_extent(struct send_ctx *sctx,
5260 enum btrfs_compare_tree_result result)
5264 BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
5266 if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
5267 if (result != BTRFS_COMPARE_TREE_DELETED)
5268 ret = process_extent(sctx, sctx->left_path,
5275 static int dir_changed(struct send_ctx *sctx, u64 dir)
5277 u64 orig_gen, new_gen;
5280 ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
5285 ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
5290 return (orig_gen != new_gen) ? 1 : 0;
5293 static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path,
5294 struct btrfs_key *key)
5296 struct btrfs_inode_extref *extref;
5297 struct extent_buffer *leaf;
5298 u64 dirid = 0, last_dirid = 0;
5305 /* Easy case, just check this one dirid */
5306 if (key->type == BTRFS_INODE_REF_KEY) {
5307 dirid = key->offset;
5309 ret = dir_changed(sctx, dirid);
5313 leaf = path->nodes[0];
5314 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
5315 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
5316 while (cur_offset < item_size) {
5317 extref = (struct btrfs_inode_extref *)(ptr +
5319 dirid = btrfs_inode_extref_parent(leaf, extref);
5320 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
5321 cur_offset += ref_name_len + sizeof(*extref);
5322 if (dirid == last_dirid)
5324 ret = dir_changed(sctx, dirid);
5334 * Updates compare related fields in sctx and simply forwards to the actual
5335 * changed_xxx functions.
5337 static int changed_cb(struct btrfs_root *left_root,
5338 struct btrfs_root *right_root,
5339 struct btrfs_path *left_path,
5340 struct btrfs_path *right_path,
5341 struct btrfs_key *key,
5342 enum btrfs_compare_tree_result result,
5346 struct send_ctx *sctx = ctx;
5348 if (result == BTRFS_COMPARE_TREE_SAME) {
5349 if (key->type == BTRFS_INODE_REF_KEY ||
5350 key->type == BTRFS_INODE_EXTREF_KEY) {
5351 ret = compare_refs(sctx, left_path, key);
5356 } else if (key->type == BTRFS_EXTENT_DATA_KEY) {
5357 return maybe_send_hole(sctx, left_path, key);
5361 result = BTRFS_COMPARE_TREE_CHANGED;
5365 sctx->left_path = left_path;
5366 sctx->right_path = right_path;
5367 sctx->cmp_key = key;
5369 ret = finish_inode_if_needed(sctx, 0);
5373 /* Ignore non-FS objects */
5374 if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
5375 key->objectid == BTRFS_FREE_SPACE_OBJECTID)
5378 if (key->type == BTRFS_INODE_ITEM_KEY)
5379 ret = changed_inode(sctx, result);
5380 else if (key->type == BTRFS_INODE_REF_KEY ||
5381 key->type == BTRFS_INODE_EXTREF_KEY)
5382 ret = changed_ref(sctx, result);
5383 else if (key->type == BTRFS_XATTR_ITEM_KEY)
5384 ret = changed_xattr(sctx, result);
5385 else if (key->type == BTRFS_EXTENT_DATA_KEY)
5386 ret = changed_extent(sctx, result);
5392 static int full_send_tree(struct send_ctx *sctx)
5395 struct btrfs_root *send_root = sctx->send_root;
5396 struct btrfs_key key;
5397 struct btrfs_key found_key;
5398 struct btrfs_path *path;
5399 struct extent_buffer *eb;
5402 path = alloc_path_for_send();
5406 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
5407 key.type = BTRFS_INODE_ITEM_KEY;
5410 ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
5417 eb = path->nodes[0];
5418 slot = path->slots[0];
5419 btrfs_item_key_to_cpu(eb, &found_key, slot);
5421 ret = changed_cb(send_root, NULL, path, NULL,
5422 &found_key, BTRFS_COMPARE_TREE_NEW, sctx);
5426 key.objectid = found_key.objectid;
5427 key.type = found_key.type;
5428 key.offset = found_key.offset + 1;
5430 ret = btrfs_next_item(send_root, path);
5440 ret = finish_inode_if_needed(sctx, 1);
5443 btrfs_free_path(path);
5447 static int send_subvol(struct send_ctx *sctx)
5451 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
5452 ret = send_header(sctx);
5457 ret = send_subvol_begin(sctx);
5461 if (sctx->parent_root) {
5462 ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
5466 ret = finish_inode_if_needed(sctx, 1);
5470 ret = full_send_tree(sctx);
5476 free_recorded_refs(sctx);
5480 static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
5482 spin_lock(&root->root_item_lock);
5483 root->send_in_progress--;
5485 * Not much left to do, we don't know why it's unbalanced and
5486 * can't blindly reset it to 0.
5488 if (root->send_in_progress < 0)
5489 btrfs_err(root->fs_info,
5490 "send_in_progres unbalanced %d root %llu\n",
5491 root->send_in_progress, root->root_key.objectid);
5492 spin_unlock(&root->root_item_lock);
5495 long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
5498 struct btrfs_root *send_root;
5499 struct btrfs_root *clone_root;
5500 struct btrfs_fs_info *fs_info;
5501 struct btrfs_ioctl_send_args *arg = NULL;
5502 struct btrfs_key key;
5503 struct send_ctx *sctx = NULL;
5505 u64 *clone_sources_tmp = NULL;
5506 int clone_sources_to_rollback = 0;
5507 int sort_clone_roots = 0;
5510 if (!capable(CAP_SYS_ADMIN))
5513 send_root = BTRFS_I(file_inode(mnt_file))->root;
5514 fs_info = send_root->fs_info;
5517 * The subvolume must remain read-only during send, protect against
5520 spin_lock(&send_root->root_item_lock);
5521 send_root->send_in_progress++;
5522 spin_unlock(&send_root->root_item_lock);
5525 * This is done when we lookup the root, it should already be complete
5526 * by the time we get here.
5528 WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE);
5531 * Userspace tools do the checks and warn the user if it's
5534 if (!btrfs_root_readonly(send_root)) {
5539 arg = memdup_user(arg_, sizeof(*arg));
5546 if (!access_ok(VERIFY_READ, arg->clone_sources,
5547 sizeof(*arg->clone_sources) *
5548 arg->clone_sources_count)) {
5553 if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
5558 sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
5564 INIT_LIST_HEAD(&sctx->new_refs);
5565 INIT_LIST_HEAD(&sctx->deleted_refs);
5566 INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
5567 INIT_LIST_HEAD(&sctx->name_cache_list);
5569 sctx->flags = arg->flags;
5571 sctx->send_filp = fget(arg->send_fd);
5572 if (!sctx->send_filp) {
5577 sctx->send_root = send_root;
5578 sctx->clone_roots_cnt = arg->clone_sources_count;
5580 sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
5581 sctx->send_buf = vmalloc(sctx->send_max_size);
5582 if (!sctx->send_buf) {
5587 sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE);
5588 if (!sctx->read_buf) {
5593 sctx->pending_dir_moves = RB_ROOT;
5594 sctx->waiting_dir_moves = RB_ROOT;
5595 sctx->orphan_dirs = RB_ROOT;
5597 sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
5598 (arg->clone_sources_count + 1));
5599 if (!sctx->clone_roots) {
5604 if (arg->clone_sources_count) {
5605 clone_sources_tmp = vmalloc(arg->clone_sources_count *
5606 sizeof(*arg->clone_sources));
5607 if (!clone_sources_tmp) {
5612 ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
5613 arg->clone_sources_count *
5614 sizeof(*arg->clone_sources));
5620 for (i = 0; i < arg->clone_sources_count; i++) {
5621 key.objectid = clone_sources_tmp[i];
5622 key.type = BTRFS_ROOT_ITEM_KEY;
5623 key.offset = (u64)-1;
5625 index = srcu_read_lock(&fs_info->subvol_srcu);
5627 clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
5628 if (IS_ERR(clone_root)) {
5629 srcu_read_unlock(&fs_info->subvol_srcu, index);
5630 ret = PTR_ERR(clone_root);
5633 clone_sources_to_rollback = i + 1;
5634 spin_lock(&clone_root->root_item_lock);
5635 clone_root->send_in_progress++;
5636 if (!btrfs_root_readonly(clone_root)) {
5637 spin_unlock(&clone_root->root_item_lock);
5638 srcu_read_unlock(&fs_info->subvol_srcu, index);
5642 spin_unlock(&clone_root->root_item_lock);
5643 srcu_read_unlock(&fs_info->subvol_srcu, index);
5645 sctx->clone_roots[i].root = clone_root;
5647 vfree(clone_sources_tmp);
5648 clone_sources_tmp = NULL;
5651 if (arg->parent_root) {
5652 key.objectid = arg->parent_root;
5653 key.type = BTRFS_ROOT_ITEM_KEY;
5654 key.offset = (u64)-1;
5656 index = srcu_read_lock(&fs_info->subvol_srcu);
5658 sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
5659 if (IS_ERR(sctx->parent_root)) {
5660 srcu_read_unlock(&fs_info->subvol_srcu, index);
5661 ret = PTR_ERR(sctx->parent_root);
5665 spin_lock(&sctx->parent_root->root_item_lock);
5666 sctx->parent_root->send_in_progress++;
5667 if (!btrfs_root_readonly(sctx->parent_root)) {
5668 spin_unlock(&sctx->parent_root->root_item_lock);
5669 srcu_read_unlock(&fs_info->subvol_srcu, index);
5673 spin_unlock(&sctx->parent_root->root_item_lock);
5675 srcu_read_unlock(&fs_info->subvol_srcu, index);
5679 * Clones from send_root are allowed, but only if the clone source
5680 * is behind the current send position. This is checked while searching
5681 * for possible clone sources.
5683 sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;
5685 /* We do a bsearch later */
5686 sort(sctx->clone_roots, sctx->clone_roots_cnt,
5687 sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
5689 sort_clone_roots = 1;
5691 current->journal_info = (void *)BTRFS_SEND_TRANS_STUB;
5692 ret = send_subvol(sctx);
5693 current->journal_info = NULL;
5697 if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) {
5698 ret = begin_cmd(sctx, BTRFS_SEND_C_END);
5701 ret = send_cmd(sctx);
5707 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
5708 while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
5710 struct pending_dir_move *pm;
5712 n = rb_first(&sctx->pending_dir_moves);
5713 pm = rb_entry(n, struct pending_dir_move, node);
5714 while (!list_empty(&pm->list)) {
5715 struct pending_dir_move *pm2;
5717 pm2 = list_first_entry(&pm->list,
5718 struct pending_dir_move, list);
5719 free_pending_move(sctx, pm2);
5721 free_pending_move(sctx, pm);
5724 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
5725 while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
5727 struct waiting_dir_move *dm;
5729 n = rb_first(&sctx->waiting_dir_moves);
5730 dm = rb_entry(n, struct waiting_dir_move, node);
5731 rb_erase(&dm->node, &sctx->waiting_dir_moves);
5735 WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->orphan_dirs));
5736 while (sctx && !RB_EMPTY_ROOT(&sctx->orphan_dirs)) {
5738 struct orphan_dir_info *odi;
5740 n = rb_first(&sctx->orphan_dirs);
5741 odi = rb_entry(n, struct orphan_dir_info, node);
5742 free_orphan_dir_info(sctx, odi);
5745 if (sort_clone_roots) {
5746 for (i = 0; i < sctx->clone_roots_cnt; i++)
5747 btrfs_root_dec_send_in_progress(
5748 sctx->clone_roots[i].root);
5750 for (i = 0; sctx && i < clone_sources_to_rollback; i++)
5751 btrfs_root_dec_send_in_progress(
5752 sctx->clone_roots[i].root);
5754 btrfs_root_dec_send_in_progress(send_root);
5756 if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
5757 btrfs_root_dec_send_in_progress(sctx->parent_root);
5760 vfree(clone_sources_tmp);
5763 if (sctx->send_filp)
5764 fput(sctx->send_filp);
5766 vfree(sctx->clone_roots);
5767 vfree(sctx->send_buf);
5768 vfree(sctx->read_buf);
5770 name_cache_free(sctx);