1/*
   2 * Copyright (C) 2012 Alexander Block.  All rights reserved.
   3 *
   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.
   7 *
   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.
  12 *
  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.
  17 */
  18
  19#include <linux/bsearch.h>
  20#include <linux/fs.h>
  21#include <linux/file.h>
  22#include <linux/sort.h>
  23#include <linux/mount.h>
  24#include <linux/xattr.h>
  25#include <linux/posix_acl_xattr.h>
  26#include <linux/radix-tree.h>
  27#include <linux/vmalloc.h>
  28#include <linux/string.h>
 
 
 
  29
  30#include "send.h"
 
  31#include "backref.h"
  32#include "hash.h"
  33#include "locking.h"
  34#include "disk-io.h"
  35#include "btrfs_inode.h"
  36#include "transaction.h"
 
 
 
 
 
 
 
 
  37
  38static int g_verbose = 0;
  39
  40#define verbose_printk(...) if (g_verbose) printk(__VA_ARGS__)
 
 
 
 
  41
  42/*
  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.
  48 */
  49struct fs_path {
  50	union {
  51		struct {
  52			char *start;
  53			char *end;
  54
  55			char *buf;
  56			unsigned short buf_len:15;
  57			unsigned short reversed:1;
  58			char inline_buf[];
  59		};
  60		/*
  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.
  64		 */
  65		char pad[256];
  66	};
  67};
  68#define FS_PATH_INLINE_SIZE \
  69	(sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))
  70
  71
  72/* reused for each extent */
  73struct clone_root {
  74	struct btrfs_root *root;
  75	u64 ino;
  76	u64 offset;
 
 
 
 
 
  77
  78	u64 found_refs;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  79};
  80
  81#define SEND_CTX_MAX_NAME_CACHE_SIZE 128
  82#define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  83
  84struct send_ctx {
  85	struct file *send_filp;
  86	loff_t send_off;
  87	char *send_buf;
  88	u32 send_size;
  89	u32 send_max_size;
  90	u64 total_send_size;
  91	u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
 
 
 
 
  92	u64 flags;	/* 'flags' member of btrfs_ioctl_send_args is u64 */
 
 
  93
  94	struct btrfs_root *send_root;
  95	struct btrfs_root *parent_root;
  96	struct clone_root *clone_roots;
  97	int clone_roots_cnt;
  98
  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;
 103
 104	/*
 
 
 
 
 
 
 
 
 
 105	 * infos of the currently processed inode. In case of deleted inodes,
 106	 * these are the values from the deleted inode.
 107	 */
 108	u64 cur_ino;
 109	u64 cur_inode_gen;
 110	int cur_inode_new;
 111	int cur_inode_new_gen;
 112	int cur_inode_deleted;
 113	u64 cur_inode_size;
 114	u64 cur_inode_mode;
 115	u64 cur_inode_rdev;
 116	u64 cur_inode_last_extent;
 
 
 
 
 
 
 
 117
 118	u64 send_progress;
 119
 120	struct list_head new_refs;
 121	struct list_head deleted_refs;
 122
 123	struct radix_tree_root name_cache;
 124	struct list_head name_cache_list;
 125	int name_cache_size;
 126
 
 
 
 
 
 127	struct file_ra_state ra;
 128
 129	char *read_buf;
 130
 131	/*
 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.
 141	 *
 142	 * Tree state when the first send was performed:
 143	 *
 144	 * .
 145	 * |-- a                   (ino 257)
 146	 *     |-- b               (ino 258)
 147	 *         |
 148	 *         |
 149	 *         |-- c           (ino 259)
 150	 *         |   |-- d       (ino 260)
 151	 *         |
 152	 *         |-- c2          (ino 261)
 153	 *
 154	 * Tree state when the second (incremental) send is performed:
 155	 *
 156	 * .
 157	 * |-- a                   (ino 257)
 158	 *     |-- b               (ino 258)
 159	 *         |-- c2          (ino 261)
 160	 *             |-- d2      (ino 260)
 161	 *                 |-- cc  (ino 259)
 162	 *
 163	 * The sequence of steps that lead to the second state was:
 164	 *
 165	 * mv /a/b/c/d /a/b/c2/d2
 166	 * mv /a/b/c /a/b/c2/d2/cc
 167	 *
 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.
 170	 *
 171	 * So we just memorize which move/rename operations must be performed
 172	 * later when their respective parent is processed and moved/renamed.
 173	 */
 174
 175	/* Indexed by parent directory inode number. */
 176	struct rb_root pending_dir_moves;
 177
 178	/*
 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.
 182	 */
 183	struct rb_root waiting_dir_moves;
 184
 185	/*
 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:
 190	 *
 191	 * Parent snapshot:
 192	 *
 193	 * .                        (ino 256)
 194	 * |-- a/                   (ino 257)
 195	 *     |-- b/               (ino 258)
 196	 *         |-- c/           (ino 259)
 197	 *         |   |-- x/       (ino 260)
 198	 *         |
 199	 *         |-- y/           (ino 261)
 200	 *
 201	 * Send snapshot:
 202	 *
 203	 * .                        (ino 256)
 204	 * |-- a/                   (ino 257)
 205	 *     |-- b/               (ino 258)
 206	 *         |-- YY/          (ino 261)
 207	 *              |-- x/      (ino 260)
 208	 *
 209	 * Sequence of steps that lead to the send snapshot:
 210	 * rm -f /a/b/c/foo.txt
 211	 * mv /a/b/y /a/b/YY
 212	 * mv /a/b/c/x /a/b/YY
 213	 * rmdir /a/b/c
 214	 *
 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.
 221	 *
 222	 * Indexed by the inode number of the directory to be deleted.
 223	 */
 224	struct rb_root orphan_dirs;
 
 
 
 
 
 
 
 
 
 225};
 226
 227struct pending_dir_move {
 228	struct rb_node node;
 229	struct list_head list;
 230	u64 parent_ino;
 231	u64 ino;
 232	u64 gen;
 233	struct list_head update_refs;
 234};
 235
 236struct waiting_dir_move {
 237	struct rb_node node;
 238	u64 ino;
 239	/*
 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.
 243	 */
 244	u64 rmdir_ino;
 
 
 245};
 246
 247struct orphan_dir_info {
 248	struct rb_node node;
 249	u64 ino;
 250	u64 gen;
 
 
 251};
 252
 253struct name_cache_entry {
 254	struct list_head list;
 255	/*
 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
 261	 * generations.
 262	 */
 263	struct list_head radix_list;
 264	u64 ino;
 265	u64 gen;
 266	u64 parent_ino;
 267	u64 parent_gen;
 268	int ret;
 269	int need_later_update;
 
 270	int name_len;
 271	char name[];
 
 272};
 273
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 274static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);
 275
 276static struct waiting_dir_move *
 277get_waiting_dir_move(struct send_ctx *sctx, u64 ino);
 278
 279static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino);
 280
 281static int need_send_hole(struct send_ctx *sctx)
 282{
 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));
 286}
 287
 288static void fs_path_reset(struct fs_path *p)
 289{
 290	if (p->reversed) {
 291		p->start = p->buf + p->buf_len - 1;
 292		p->end = p->start;
 293		*p->start = 0;
 294	} else {
 295		p->start = p->buf;
 296		p->end = p->start;
 297		*p->start = 0;
 298	}
 299}
 300
 301static struct fs_path *fs_path_alloc(void)
 302{
 303	struct fs_path *p;
 304
 305	p = kmalloc(sizeof(*p), GFP_NOFS);
 306	if (!p)
 307		return NULL;
 308	p->reversed = 0;
 309	p->buf = p->inline_buf;
 310	p->buf_len = FS_PATH_INLINE_SIZE;
 311	fs_path_reset(p);
 312	return p;
 313}
 314
 315static struct fs_path *fs_path_alloc_reversed(void)
 316{
 317	struct fs_path *p;
 318
 319	p = fs_path_alloc();
 320	if (!p)
 321		return NULL;
 322	p->reversed = 1;
 323	fs_path_reset(p);
 324	return p;
 325}
 326
 327static void fs_path_free(struct fs_path *p)
 328{
 329	if (!p)
 330		return;
 331	if (p->buf != p->inline_buf)
 332		kfree(p->buf);
 333	kfree(p);
 334}
 335
 336static int fs_path_len(struct fs_path *p)
 337{
 338	return p->end - p->start;
 339}
 340
 341static int fs_path_ensure_buf(struct fs_path *p, int len)
 342{
 343	char *tmp_buf;
 344	int path_len;
 345	int old_buf_len;
 346
 347	len++;
 348
 349	if (p->buf_len >= len)
 350		return 0;
 351
 352	if (len > PATH_MAX) {
 353		WARN_ON(1);
 354		return -ENOMEM;
 355	}
 356
 357	path_len = p->end - p->start;
 358	old_buf_len = p->buf_len;
 359
 360	/*
 
 
 
 
 
 361	 * First time the inline_buf does not suffice
 362	 */
 363	if (p->buf == p->inline_buf) {
 364		tmp_buf = kmalloc(len, GFP_NOFS);
 365		if (tmp_buf)
 366			memcpy(tmp_buf, p->buf, old_buf_len);
 367	} else {
 368		tmp_buf = krealloc(p->buf, len, GFP_NOFS);
 369	}
 370	if (!tmp_buf)
 371		return -ENOMEM;
 372	p->buf = tmp_buf;
 373	/*
 374	 * The real size of the buffer is bigger, this will let the fast path
 375	 * happen most of the time
 376	 */
 377	p->buf_len = ksize(p->buf);
 378
 379	if (p->reversed) {
 380		tmp_buf = p->buf + old_buf_len - path_len - 1;
 381		p->end = p->buf + p->buf_len - 1;
 382		p->start = p->end - path_len;
 383		memmove(p->start, tmp_buf, path_len + 1);
 384	} else {
 385		p->start = p->buf;
 386		p->end = p->start + path_len;
 387	}
 388	return 0;
 389}
 390
 391static int fs_path_prepare_for_add(struct fs_path *p, int name_len,
 392				   char **prepared)
 393{
 394	int ret;
 395	int new_len;
 396
 397	new_len = p->end - p->start + name_len;
 398	if (p->start != p->end)
 399		new_len++;
 400	ret = fs_path_ensure_buf(p, new_len);
 401	if (ret < 0)
 402		goto out;
 403
 404	if (p->reversed) {
 405		if (p->start != p->end)
 406			*--p->start = '/';
 407		p->start -= name_len;
 408		*prepared = p->start;
 409	} else {
 410		if (p->start != p->end)
 411			*p->end++ = '/';
 412		*prepared = p->end;
 413		p->end += name_len;
 414		*p->end = 0;
 415	}
 416
 417out:
 418	return ret;
 419}
 420
 421static int fs_path_add(struct fs_path *p, const char *name, int name_len)
 422{
 423	int ret;
 424	char *prepared;
 425
 426	ret = fs_path_prepare_for_add(p, name_len, &prepared);
 427	if (ret < 0)
 428		goto out;
 429	memcpy(prepared, name, name_len);
 430
 431out:
 432	return ret;
 433}
 434
 435static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
 436{
 437	int ret;
 438	char *prepared;
 439
 440	ret = fs_path_prepare_for_add(p, p2->end - p2->start, &prepared);
 441	if (ret < 0)
 442		goto out;
 443	memcpy(prepared, p2->start, p2->end - p2->start);
 444
 445out:
 446	return ret;
 447}
 448
 449static int fs_path_add_from_extent_buffer(struct fs_path *p,
 450					  struct extent_buffer *eb,
 451					  unsigned long off, int len)
 452{
 453	int ret;
 454	char *prepared;
 455
 456	ret = fs_path_prepare_for_add(p, len, &prepared);
 457	if (ret < 0)
 458		goto out;
 459
 460	read_extent_buffer(eb, prepared, off, len);
 461
 462out:
 463	return ret;
 464}
 465
 466static int fs_path_copy(struct fs_path *p, struct fs_path *from)
 467{
 468	int ret;
 469
 470	p->reversed = from->reversed;
 471	fs_path_reset(p);
 472
 473	ret = fs_path_add_path(p, from);
 474
 475	return ret;
 476}
 477
 478
 479static void fs_path_unreverse(struct fs_path *p)
 480{
 481	char *tmp;
 482	int len;
 483
 484	if (!p->reversed)
 485		return;
 486
 487	tmp = p->start;
 488	len = p->end - p->start;
 489	p->start = p->buf;
 490	p->end = p->start + len;
 491	memmove(p->start, tmp, len + 1);
 492	p->reversed = 0;
 493}
 494
 495static struct btrfs_path *alloc_path_for_send(void)
 496{
 497	struct btrfs_path *path;
 498
 499	path = btrfs_alloc_path();
 500	if (!path)
 501		return NULL;
 502	path->search_commit_root = 1;
 503	path->skip_locking = 1;
 504	path->need_commit_sem = 1;
 505	return path;
 506}
 507
 508static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
 509{
 510	int ret;
 511	mm_segment_t old_fs;
 512	u32 pos = 0;
 513
 514	old_fs = get_fs();
 515	set_fs(KERNEL_DS);
 516
 517	while (pos < len) {
 518		ret = vfs_write(filp, (char *)buf + pos, len - pos, off);
 519		/* TODO handle that correctly */
 520		/*if (ret == -ERESTARTSYS) {
 521			continue;
 522		}*/
 523		if (ret < 0)
 524			goto out;
 525		if (ret == 0) {
 526			ret = -EIO;
 527			goto out;
 528		}
 529		pos += ret;
 530	}
 531
 532	ret = 0;
 533
 534out:
 535	set_fs(old_fs);
 536	return ret;
 537}
 538
 539static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
 540{
 541	struct btrfs_tlv_header *hdr;
 542	int total_len = sizeof(*hdr) + len;
 543	int left = sctx->send_max_size - sctx->send_size;
 544
 
 
 
 545	if (unlikely(left < total_len))
 546		return -EOVERFLOW;
 547
 548	hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
 549	hdr->tlv_type = cpu_to_le16(attr);
 550	hdr->tlv_len = cpu_to_le16(len);
 551	memcpy(hdr + 1, data, len);
 552	sctx->send_size += total_len;
 553
 554	return 0;
 555}
 556
 557#define TLV_PUT_DEFINE_INT(bits) \
 558	static int tlv_put_u##bits(struct send_ctx *sctx,	 	\
 559			u##bits attr, u##bits value)			\
 560	{								\
 561		__le##bits __tmp = cpu_to_le##bits(value);		\
 562		return tlv_put(sctx, attr, &__tmp, sizeof(__tmp));	\
 563	}
 564
 
 
 565TLV_PUT_DEFINE_INT(64)
 566
 567static int tlv_put_string(struct send_ctx *sctx, u16 attr,
 568			  const char *str, int len)
 569{
 570	if (len == -1)
 571		len = strlen(str);
 572	return tlv_put(sctx, attr, str, len);
 573}
 574
 575static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
 576			const u8 *uuid)
 577{
 578	return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
 579}
 580
 581static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
 582				  struct extent_buffer *eb,
 583				  struct btrfs_timespec *ts)
 584{
 585	struct btrfs_timespec bts;
 586	read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
 587	return tlv_put(sctx, attr, &bts, sizeof(bts));
 588}
 589
 590
 591#define TLV_PUT(sctx, attrtype, attrlen, data) \
 592	do { \
 593		ret = tlv_put(sctx, attrtype, attrlen, data); \
 594		if (ret < 0) \
 595			goto tlv_put_failure; \
 596	} while (0)
 597
 598#define TLV_PUT_INT(sctx, attrtype, bits, value) \
 599	do { \
 600		ret = tlv_put_u##bits(sctx, attrtype, value); \
 601		if (ret < 0) \
 602			goto tlv_put_failure; \
 603	} while (0)
 604
 605#define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
 606#define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
 607#define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
 608#define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
 609#define TLV_PUT_STRING(sctx, attrtype, str, len) \
 610	do { \
 611		ret = tlv_put_string(sctx, attrtype, str, len); \
 612		if (ret < 0) \
 613			goto tlv_put_failure; \
 614	} while (0)
 615#define TLV_PUT_PATH(sctx, attrtype, p) \
 616	do { \
 617		ret = tlv_put_string(sctx, attrtype, p->start, \
 618			p->end - p->start); \
 619		if (ret < 0) \
 620			goto tlv_put_failure; \
 621	} while(0)
 622#define TLV_PUT_UUID(sctx, attrtype, uuid) \
 623	do { \
 624		ret = tlv_put_uuid(sctx, attrtype, uuid); \
 625		if (ret < 0) \
 626			goto tlv_put_failure; \
 627	} while (0)
 628#define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
 629	do { \
 630		ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
 631		if (ret < 0) \
 632			goto tlv_put_failure; \
 633	} while (0)
 634
 635static int send_header(struct send_ctx *sctx)
 636{
 637	struct btrfs_stream_header hdr;
 638
 639	strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
 640	hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);
 641
 642	return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
 643					&sctx->send_off);
 644}
 645
 646/*
 647 * For each command/item we want to send to userspace, we call this function.
 648 */
 649static int begin_cmd(struct send_ctx *sctx, int cmd)
 650{
 651	struct btrfs_cmd_header *hdr;
 652
 653	if (WARN_ON(!sctx->send_buf))
 654		return -EINVAL;
 655
 656	BUG_ON(sctx->send_size);
 
 
 
 
 
 657
 658	sctx->send_size += sizeof(*hdr);
 659	hdr = (struct btrfs_cmd_header *)sctx->send_buf;
 660	hdr->cmd = cpu_to_le16(cmd);
 661
 662	return 0;
 663}
 664
 665static int send_cmd(struct send_ctx *sctx)
 666{
 667	int ret;
 668	struct btrfs_cmd_header *hdr;
 669	u32 crc;
 670
 671	hdr = (struct btrfs_cmd_header *)sctx->send_buf;
 672	hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
 673	hdr->crc = 0;
 674
 675	crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
 676	hdr->crc = cpu_to_le32(crc);
 677
 678	ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
 679					&sctx->send_off);
 680
 681	sctx->total_send_size += sctx->send_size;
 682	sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
 683	sctx->send_size = 0;
 
 684
 685	return ret;
 686}
 687
 688/*
 689 * Sends a move instruction to user space
 690 */
 691static int send_rename(struct send_ctx *sctx,
 692		     struct fs_path *from, struct fs_path *to)
 693{
 
 694	int ret;
 695
 696verbose_printk("btrfs: send_rename %s -> %s\n", from->start, to->start);
 697
 698	ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
 699	if (ret < 0)
 700		goto out;
 701
 702	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
 703	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);
 704
 705	ret = send_cmd(sctx);
 706
 707tlv_put_failure:
 708out:
 709	return ret;
 710}
 711
 712/*
 713 * Sends a link instruction to user space
 714 */
 715static int send_link(struct send_ctx *sctx,
 716		     struct fs_path *path, struct fs_path *lnk)
 717{
 
 718	int ret;
 719
 720verbose_printk("btrfs: send_link %s -> %s\n", path->start, lnk->start);
 721
 722	ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
 723	if (ret < 0)
 724		goto out;
 725
 726	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
 727	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);
 728
 729	ret = send_cmd(sctx);
 730
 731tlv_put_failure:
 732out:
 733	return ret;
 734}
 735
 736/*
 737 * Sends an unlink instruction to user space
 738 */
 739static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
 740{
 
 741	int ret;
 742
 743verbose_printk("btrfs: send_unlink %s\n", path->start);
 744
 745	ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
 746	if (ret < 0)
 747		goto out;
 748
 749	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
 750
 751	ret = send_cmd(sctx);
 752
 753tlv_put_failure:
 754out:
 755	return ret;
 756}
 757
 758/*
 759 * Sends a rmdir instruction to user space
 760 */
 761static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
 762{
 
 763	int ret;
 764
 765verbose_printk("btrfs: send_rmdir %s\n", path->start);
 766
 767	ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
 768	if (ret < 0)
 769		goto out;
 770
 771	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
 772
 773	ret = send_cmd(sctx);
 774
 775tlv_put_failure:
 776out:
 777	return ret;
 778}
 779
 
 
 
 
 
 
 
 
 
 
 
 780/*
 781 * Helper function to retrieve some fields from an inode item.
 782 */
 783static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
 784			  u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid,
 785			  u64 *gid, u64 *rdev)
 786{
 787	int ret;
 
 788	struct btrfs_inode_item *ii;
 789	struct btrfs_key key;
 790
 
 
 
 
 791	key.objectid = ino;
 792	key.type = BTRFS_INODE_ITEM_KEY;
 793	key.offset = 0;
 794	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 795	if (ret) {
 796		if (ret > 0)
 797			ret = -ENOENT;
 798		return ret;
 799	}
 800
 
 
 
 801	ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
 802			struct btrfs_inode_item);
 803	if (size)
 804		*size = btrfs_inode_size(path->nodes[0], ii);
 805	if (gen)
 806		*gen = btrfs_inode_generation(path->nodes[0], ii);
 807	if (mode)
 808		*mode = btrfs_inode_mode(path->nodes[0], ii);
 809	if (uid)
 810		*uid = btrfs_inode_uid(path->nodes[0], ii);
 811	if (gid)
 812		*gid = btrfs_inode_gid(path->nodes[0], ii);
 813	if (rdev)
 814		*rdev = btrfs_inode_rdev(path->nodes[0], ii);
 815
 
 
 816	return ret;
 817}
 818
 819static int get_inode_info(struct btrfs_root *root,
 820			  u64 ino, u64 *size, u64 *gen,
 821			  u64 *mode, u64 *uid, u64 *gid,
 822			  u64 *rdev)
 823{
 824	struct btrfs_path *path;
 825	int ret;
 
 826
 827	path = alloc_path_for_send();
 828	if (!path)
 829		return -ENOMEM;
 830	ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid,
 831			       rdev);
 832	btrfs_free_path(path);
 833	return ret;
 834}
 835
 836typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
 837				   struct fs_path *p,
 838				   void *ctx);
 839
 840/*
 841 * Helper function to iterate the entries in ONE btrfs_inode_ref or
 842 * btrfs_inode_extref.
 843 * The iterate callback may return a non zero value to stop iteration. This can
 844 * be a negative value for error codes or 1 to simply stop it.
 845 *
 846 * path must point to the INODE_REF or INODE_EXTREF when called.
 847 */
 848static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
 849			     struct btrfs_key *found_key, int resolve,
 850			     iterate_inode_ref_t iterate, void *ctx)
 851{
 852	struct extent_buffer *eb = path->nodes[0];
 853	struct btrfs_item *item;
 854	struct btrfs_inode_ref *iref;
 855	struct btrfs_inode_extref *extref;
 856	struct btrfs_path *tmp_path;
 857	struct fs_path *p;
 858	u32 cur = 0;
 859	u32 total;
 860	int slot = path->slots[0];
 861	u32 name_len;
 862	char *start;
 863	int ret = 0;
 864	int num = 0;
 865	int index;
 866	u64 dir;
 867	unsigned long name_off;
 868	unsigned long elem_size;
 869	unsigned long ptr;
 870
 871	p = fs_path_alloc_reversed();
 872	if (!p)
 873		return -ENOMEM;
 874
 875	tmp_path = alloc_path_for_send();
 876	if (!tmp_path) {
 877		fs_path_free(p);
 878		return -ENOMEM;
 879	}
 880
 881
 882	if (found_key->type == BTRFS_INODE_REF_KEY) {
 883		ptr = (unsigned long)btrfs_item_ptr(eb, slot,
 884						    struct btrfs_inode_ref);
 885		item = btrfs_item_nr(slot);
 886		total = btrfs_item_size(eb, item);
 887		elem_size = sizeof(*iref);
 888	} else {
 889		ptr = btrfs_item_ptr_offset(eb, slot);
 890		total = btrfs_item_size_nr(eb, slot);
 891		elem_size = sizeof(*extref);
 892	}
 893
 894	while (cur < total) {
 895		fs_path_reset(p);
 896
 897		if (found_key->type == BTRFS_INODE_REF_KEY) {
 898			iref = (struct btrfs_inode_ref *)(ptr + cur);
 899			name_len = btrfs_inode_ref_name_len(eb, iref);
 900			name_off = (unsigned long)(iref + 1);
 901			index = btrfs_inode_ref_index(eb, iref);
 902			dir = found_key->offset;
 903		} else {
 904			extref = (struct btrfs_inode_extref *)(ptr + cur);
 905			name_len = btrfs_inode_extref_name_len(eb, extref);
 906			name_off = (unsigned long)&extref->name;
 907			index = btrfs_inode_extref_index(eb, extref);
 908			dir = btrfs_inode_extref_parent(eb, extref);
 909		}
 910
 911		if (resolve) {
 912			start = btrfs_ref_to_path(root, tmp_path, name_len,
 913						  name_off, eb, dir,
 914						  p->buf, p->buf_len);
 915			if (IS_ERR(start)) {
 916				ret = PTR_ERR(start);
 917				goto out;
 918			}
 919			if (start < p->buf) {
 920				/* overflow , try again with larger buffer */
 921				ret = fs_path_ensure_buf(p,
 922						p->buf_len + p->buf - start);
 923				if (ret < 0)
 924					goto out;
 925				start = btrfs_ref_to_path(root, tmp_path,
 926							  name_len, name_off,
 927							  eb, dir,
 928							  p->buf, p->buf_len);
 929				if (IS_ERR(start)) {
 930					ret = PTR_ERR(start);
 931					goto out;
 932				}
 933				BUG_ON(start < p->buf);
 
 
 
 
 
 
 
 
 934			}
 935			p->start = start;
 936		} else {
 937			ret = fs_path_add_from_extent_buffer(p, eb, name_off,
 938							     name_len);
 939			if (ret < 0)
 940				goto out;
 941		}
 942
 943		cur += elem_size + name_len;
 944		ret = iterate(num, dir, index, p, ctx);
 945		if (ret)
 946			goto out;
 947		num++;
 948	}
 949
 950out:
 951	btrfs_free_path(tmp_path);
 952	fs_path_free(p);
 953	return ret;
 954}
 955
 956typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
 957				  const char *name, int name_len,
 958				  const char *data, int data_len,
 959				  u8 type, void *ctx);
 960
 961/*
 962 * Helper function to iterate the entries in ONE btrfs_dir_item.
 963 * The iterate callback may return a non zero value to stop iteration. This can
 964 * be a negative value for error codes or 1 to simply stop it.
 965 *
 966 * path must point to the dir item when called.
 967 */
 968static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
 969			    struct btrfs_key *found_key,
 970			    iterate_dir_item_t iterate, void *ctx)
 971{
 972	int ret = 0;
 973	struct extent_buffer *eb;
 974	struct btrfs_item *item;
 975	struct btrfs_dir_item *di;
 976	struct btrfs_key di_key;
 977	char *buf = NULL;
 978	const int buf_len = PATH_MAX;
 979	u32 name_len;
 980	u32 data_len;
 981	u32 cur;
 982	u32 len;
 983	u32 total;
 984	int slot;
 985	int num;
 986	u8 type;
 987
 988	buf = kmalloc(buf_len, GFP_NOFS);
 
 
 
 
 
 
 
 989	if (!buf) {
 990		ret = -ENOMEM;
 991		goto out;
 992	}
 993
 994	eb = path->nodes[0];
 995	slot = path->slots[0];
 996	item = btrfs_item_nr(slot);
 997	di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
 998	cur = 0;
 999	len = 0;
1000	total = btrfs_item_size(eb, item);
1001
1002	num = 0;
1003	while (cur < total) {
1004		name_len = btrfs_dir_name_len(eb, di);
1005		data_len = btrfs_dir_data_len(eb, di);
1006		type = btrfs_dir_type(eb, di);
1007		btrfs_dir_item_key_to_cpu(eb, di, &di_key);
1008
1009		/*
1010		 * Path too long
1011		 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1012		if (name_len + data_len > buf_len) {
1013			ret = -ENAMETOOLONG;
1014			goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1015		}
1016
1017		read_extent_buffer(eb, buf, (unsigned long)(di + 1),
1018				name_len + data_len);
1019
1020		len = sizeof(*di) + name_len + data_len;
1021		di = (struct btrfs_dir_item *)((char *)di + len);
1022		cur += len;
1023
1024		ret = iterate(num, &di_key, buf, name_len, buf + name_len,
1025				data_len, type, ctx);
1026		if (ret < 0)
1027			goto out;
1028		if (ret) {
1029			ret = 0;
1030			goto out;
1031		}
1032
1033		num++;
1034	}
1035
1036out:
1037	kfree(buf);
1038	return ret;
1039}
1040
1041static int __copy_first_ref(int num, u64 dir, int index,
1042			    struct fs_path *p, void *ctx)
1043{
1044	int ret;
1045	struct fs_path *pt = ctx;
1046
1047	ret = fs_path_copy(pt, p);
1048	if (ret < 0)
1049		return ret;
1050
1051	/* we want the first only */
1052	return 1;
1053}
1054
1055/*
1056 * Retrieve the first path of an inode. If an inode has more then one
1057 * ref/hardlink, this is ignored.
1058 */
1059static int get_inode_path(struct btrfs_root *root,
1060			  u64 ino, struct fs_path *path)
1061{
1062	int ret;
1063	struct btrfs_key key, found_key;
1064	struct btrfs_path *p;
1065
1066	p = alloc_path_for_send();
1067	if (!p)
1068		return -ENOMEM;
1069
1070	fs_path_reset(path);
1071
1072	key.objectid = ino;
1073	key.type = BTRFS_INODE_REF_KEY;
1074	key.offset = 0;
1075
1076	ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
1077	if (ret < 0)
1078		goto out;
1079	if (ret) {
1080		ret = 1;
1081		goto out;
1082	}
1083	btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
1084	if (found_key.objectid != ino ||
1085	    (found_key.type != BTRFS_INODE_REF_KEY &&
1086	     found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1087		ret = -ENOENT;
1088		goto out;
1089	}
1090
1091	ret = iterate_inode_ref(root, p, &found_key, 1,
1092				__copy_first_ref, path);
1093	if (ret < 0)
1094		goto out;
1095	ret = 0;
1096
1097out:
1098	btrfs_free_path(p);
1099	return ret;
1100}
1101
1102struct backref_ctx {
1103	struct send_ctx *sctx;
1104
1105	struct btrfs_path *path;
1106	/* number of total found references */
1107	u64 found;
1108
1109	/*
1110	 * used for clones found in send_root. clones found behind cur_objectid
1111	 * and cur_offset are not considered as allowed clones.
1112	 */
1113	u64 cur_objectid;
1114	u64 cur_offset;
1115
1116	/* may be truncated in case it's the last extent in a file */
1117	u64 extent_len;
1118
1119	/* Just to check for bugs in backref resolving */
1120	int found_itself;
 
 
 
 
1121};
1122
1123static int __clone_root_cmp_bsearch(const void *key, const void *elt)
1124{
1125	u64 root = (u64)(uintptr_t)key;
1126	struct clone_root *cr = (struct clone_root *)elt;
1127
1128	if (root < cr->root->objectid)
1129		return -1;
1130	if (root > cr->root->objectid)
1131		return 1;
1132	return 0;
1133}
1134
1135static int __clone_root_cmp_sort(const void *e1, const void *e2)
1136{
1137	struct clone_root *cr1 = (struct clone_root *)e1;
1138	struct clone_root *cr2 = (struct clone_root *)e2;
1139
1140	if (cr1->root->objectid < cr2->root->objectid)
1141		return -1;
1142	if (cr1->root->objectid > cr2->root->objectid)
1143		return 1;
1144	return 0;
1145}
1146
1147/*
1148 * Called for every backref that is found for the current extent.
1149 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1150 */
1151static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
 
1152{
1153	struct backref_ctx *bctx = ctx_;
1154	struct clone_root *found;
1155	int ret;
1156	u64 i_size;
1157
1158	/* First check if the root is in the list of accepted clone sources */
1159	found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1160			bctx->sctx->clone_roots_cnt,
1161			sizeof(struct clone_root),
1162			__clone_root_cmp_bsearch);
1163	if (!found)
1164		return 0;
1165
1166	if (found->root == bctx->sctx->send_root &&
 
1167	    ino == bctx->cur_objectid &&
1168	    offset == bctx->cur_offset) {
1169		bctx->found_itself = 1;
1170	}
1171
1172	/*
1173	 * There are inodes that have extents that lie behind its i_size. Don't
1174	 * accept clones from these extents.
1175	 */
1176	ret = __get_inode_info(found->root, bctx->path, ino, &i_size, NULL, NULL,
1177			       NULL, NULL, NULL);
1178	btrfs_release_path(bctx->path);
1179	if (ret < 0)
1180		return ret;
1181
1182	if (offset + bctx->extent_len > i_size)
1183		return 0;
1184
1185	/*
1186	 * Make sure we don't consider clones from send_root that are
1187	 * behind the current inode/offset.
1188	 */
1189	if (found->root == bctx->sctx->send_root) {
1190		/*
1191		 * TODO for the moment we don't accept clones from the inode
1192		 * that is currently send. We may change this when
1193		 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
1194		 * file.
1195		 */
1196		if (ino >= bctx->cur_objectid)
1197			return 0;
1198#if 0
1199		if (ino > bctx->cur_objectid)
1200			return 0;
1201		if (offset + bctx->extent_len > bctx->cur_offset)
 
 
 
 
 
 
 
 
1202			return 0;
1203#endif
1204	}
1205
1206	bctx->found++;
1207	found->found_refs++;
1208	if (ino < found->ino) {
1209		found->ino = ino;
1210		found->offset = offset;
1211	} else if (found->ino == ino) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1212		/*
1213		 * same extent found more then once in the same file.
 
 
 
 
1214		 */
1215		if (found->offset > offset + bctx->extent_len)
1216			found->offset = offset;
1217	}
1218
 
 
 
 
 
 
 
 
 
 
1219	return 0;
1220}
1221
 
 
 
 
 
 
 
 
 
 
 
 
1222/*
1223 * Given an inode, offset and extent item, it finds a good clone for a clone
1224 * instruction. Returns -ENOENT when none could be found. The function makes
1225 * sure that the returned clone is usable at the point where sending is at the
1226 * moment. This means, that no clones are accepted which lie behind the current
1227 * inode+offset.
1228 *
1229 * path must point to the extent item when called.
1230 */
1231static int find_extent_clone(struct send_ctx *sctx,
1232			     struct btrfs_path *path,
1233			     u64 ino, u64 data_offset,
1234			     u64 ino_size,
1235			     struct clone_root **found)
1236{
 
1237	int ret;
1238	int extent_type;
1239	u64 logical;
1240	u64 disk_byte;
1241	u64 num_bytes;
1242	u64 extent_item_pos;
1243	u64 flags = 0;
1244	struct btrfs_file_extent_item *fi;
1245	struct extent_buffer *eb = path->nodes[0];
1246	struct backref_ctx *backref_ctx = NULL;
 
1247	struct clone_root *cur_clone_root;
1248	struct btrfs_key found_key;
1249	struct btrfs_path *tmp_path;
1250	int compressed;
1251	u32 i;
1252
1253	tmp_path = alloc_path_for_send();
1254	if (!tmp_path)
1255		return -ENOMEM;
1256
1257	/* We only use this path under the commit sem */
1258	tmp_path->need_commit_sem = 0;
1259
1260	backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
1261	if (!backref_ctx) {
1262		ret = -ENOMEM;
1263		goto out;
1264	}
1265
1266	backref_ctx->path = tmp_path;
 
 
 
1267
1268	if (data_offset >= ino_size) {
1269		/*
1270		 * There may be extents that lie behind the file's size.
1271		 * I at least had this in combination with snapshotting while
1272		 * writing large files.
1273		 */
1274		ret = 0;
1275		goto out;
1276	}
1277
1278	fi = btrfs_item_ptr(eb, path->slots[0],
1279			struct btrfs_file_extent_item);
1280	extent_type = btrfs_file_extent_type(eb, fi);
1281	if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1282		ret = -ENOENT;
1283		goto out;
1284	}
1285	compressed = btrfs_file_extent_compression(eb, fi);
1286
1287	num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1288	disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
1289	if (disk_byte == 0) {
1290		ret = -ENOENT;
1291		goto out;
1292	}
1293	logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1294
1295	down_read(&sctx->send_root->fs_info->commit_root_sem);
1296	ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path,
1297				  &found_key, &flags);
1298	up_read(&sctx->send_root->fs_info->commit_root_sem);
1299	btrfs_release_path(tmp_path);
1300
1301	if (ret < 0)
1302		goto out;
1303	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1304		ret = -EIO;
1305		goto out;
1306	}
1307
1308	/*
1309	 * Setup the clone roots.
1310	 */
1311	for (i = 0; i < sctx->clone_roots_cnt; i++) {
1312		cur_clone_root = sctx->clone_roots + i;
1313		cur_clone_root->ino = (u64)-1;
1314		cur_clone_root->offset = 0;
1315		cur_clone_root->found_refs = 0;
 
1316	}
1317
1318	backref_ctx->sctx = sctx;
1319	backref_ctx->found = 0;
1320	backref_ctx->cur_objectid = ino;
1321	backref_ctx->cur_offset = data_offset;
1322	backref_ctx->found_itself = 0;
1323	backref_ctx->extent_len = num_bytes;
 
 
 
 
1324
1325	/*
1326	 * The last extent of a file may be too large due to page alignment.
1327	 * We need to adjust extent_len in this case so that the checks in
1328	 * __iterate_backrefs work.
1329	 */
1330	if (data_offset + num_bytes >= ino_size)
1331		backref_ctx->extent_len = ino_size - data_offset;
 
 
1332
1333	/*
1334	 * Now collect all backrefs.
1335	 */
 
1336	if (compressed == BTRFS_COMPRESS_NONE)
1337		extent_item_pos = logical - found_key.objectid;
1338	else
1339		extent_item_pos = 0;
1340	ret = iterate_extent_inodes(sctx->send_root->fs_info,
1341					found_key.objectid, extent_item_pos, 1,
1342					__iterate_backrefs, backref_ctx);
 
 
 
 
 
 
 
 
 
 
 
 
1343
 
 
1344	if (ret < 0)
1345		goto out;
1346
1347	if (!backref_ctx->found_itself) {
1348		/* found a bug in backref code? */
1349		ret = -EIO;
1350		btrfs_err(sctx->send_root->fs_info, "did not find backref in "
1351				"send_root. inode=%llu, offset=%llu, "
1352				"disk_byte=%llu found extent=%llu\n",
1353				ino, data_offset, disk_byte, found_key.objectid);
1354		goto out;
 
 
 
 
 
 
 
 
1355	}
 
1356
1357verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "
1358		"ino=%llu, "
1359		"num_bytes=%llu, logical=%llu\n",
1360		data_offset, ino, num_bytes, logical);
1361
1362	if (!backref_ctx->found)
1363		verbose_printk("btrfs:    no clones found\n");
 
 
1364
1365	cur_clone_root = NULL;
1366	for (i = 0; i < sctx->clone_roots_cnt; i++) {
1367		if (sctx->clone_roots[i].found_refs) {
1368			if (!cur_clone_root)
1369				cur_clone_root = sctx->clone_roots + i;
1370			else if (sctx->clone_roots[i].root == sctx->send_root)
1371				/* prefer clones from send_root over others */
1372				cur_clone_root = sctx->clone_roots + i;
1373		}
1374
1375	}
 
 
 
 
 
 
 
 
 
 
1376
1377	if (cur_clone_root) {
1378		if (compressed != BTRFS_COMPRESS_NONE) {
1379			/*
1380			 * Offsets given by iterate_extent_inodes() are relative
1381			 * to the start of the extent, we need to add logical
1382			 * offset from the file extent item.
1383			 * (See why at backref.c:check_extent_in_eb())
1384			 */
1385			cur_clone_root->offset += btrfs_file_extent_offset(eb,
1386									   fi);
1387		}
 
 
 
1388		*found = cur_clone_root;
1389		ret = 0;
1390	} else {
1391		ret = -ENOENT;
1392	}
1393
1394out:
1395	btrfs_free_path(tmp_path);
1396	kfree(backref_ctx);
1397	return ret;
1398}
1399
1400static int read_symlink(struct btrfs_root *root,
1401			u64 ino,
1402			struct fs_path *dest)
1403{
1404	int ret;
1405	struct btrfs_path *path;
1406	struct btrfs_key key;
1407	struct btrfs_file_extent_item *ei;
1408	u8 type;
1409	u8 compression;
1410	unsigned long off;
1411	int len;
1412
1413	path = alloc_path_for_send();
1414	if (!path)
1415		return -ENOMEM;
1416
1417	key.objectid = ino;
1418	key.type = BTRFS_EXTENT_DATA_KEY;
1419	key.offset = 0;
1420	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1421	if (ret < 0)
1422		goto out;
1423	BUG_ON(ret);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1424
1425	ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
1426			struct btrfs_file_extent_item);
1427	type = btrfs_file_extent_type(path->nodes[0], ei);
 
 
 
 
 
 
 
1428	compression = btrfs_file_extent_compression(path->nodes[0], ei);
1429	BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
1430	BUG_ON(compression);
 
 
 
 
 
1431
1432	off = btrfs_file_extent_inline_start(ei);
1433	len = btrfs_file_extent_inline_len(path->nodes[0], path->slots[0], ei);
1434
1435	ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);
1436
1437out:
1438	btrfs_free_path(path);
1439	return ret;
1440}
1441
1442/*
1443 * Helper function to generate a file name that is unique in the root of
1444 * send_root and parent_root. This is used to generate names for orphan inodes.
1445 */
1446static int gen_unique_name(struct send_ctx *sctx,
1447			   u64 ino, u64 gen,
1448			   struct fs_path *dest)
1449{
1450	int ret = 0;
1451	struct btrfs_path *path;
1452	struct btrfs_dir_item *di;
1453	char tmp[64];
1454	int len;
1455	u64 idx = 0;
1456
1457	path = alloc_path_for_send();
1458	if (!path)
1459		return -ENOMEM;
1460
1461	while (1) {
 
 
1462		len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
1463				ino, gen, idx);
1464		ASSERT(len < sizeof(tmp));
 
 
1465
1466		di = btrfs_lookup_dir_item(NULL, sctx->send_root,
1467				path, BTRFS_FIRST_FREE_OBJECTID,
1468				tmp, strlen(tmp), 0);
1469		btrfs_release_path(path);
1470		if (IS_ERR(di)) {
1471			ret = PTR_ERR(di);
1472			goto out;
1473		}
1474		if (di) {
1475			/* not unique, try again */
1476			idx++;
1477			continue;
1478		}
1479
1480		if (!sctx->parent_root) {
1481			/* unique */
1482			ret = 0;
1483			break;
1484		}
1485
1486		di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
1487				path, BTRFS_FIRST_FREE_OBJECTID,
1488				tmp, strlen(tmp), 0);
1489		btrfs_release_path(path);
1490		if (IS_ERR(di)) {
1491			ret = PTR_ERR(di);
1492			goto out;
1493		}
1494		if (di) {
1495			/* not unique, try again */
1496			idx++;
1497			continue;
1498		}
1499		/* unique */
1500		break;
1501	}
1502
1503	ret = fs_path_add(dest, tmp, strlen(tmp));
1504
1505out:
1506	btrfs_free_path(path);
1507	return ret;
1508}
1509
1510enum inode_state {
1511	inode_state_no_change,
1512	inode_state_will_create,
1513	inode_state_did_create,
1514	inode_state_will_delete,
1515	inode_state_did_delete,
1516};
1517
1518static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
 
1519{
1520	int ret;
1521	int left_ret;
1522	int right_ret;
1523	u64 left_gen;
1524	u64 right_gen;
 
1525
1526	ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1527			NULL, NULL);
1528	if (ret < 0 && ret != -ENOENT)
1529		goto out;
1530	left_ret = ret;
 
 
 
1531
1532	if (!sctx->parent_root) {
1533		right_ret = -ENOENT;
1534	} else {
1535		ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1536				NULL, NULL, NULL, NULL);
1537		if (ret < 0 && ret != -ENOENT)
1538			goto out;
1539		right_ret = ret;
 
 
 
1540	}
1541
1542	if (!left_ret && !right_ret) {
1543		if (left_gen == gen && right_gen == gen) {
1544			ret = inode_state_no_change;
1545		} else if (left_gen == gen) {
1546			if (ino < sctx->send_progress)
1547				ret = inode_state_did_create;
1548			else
1549				ret = inode_state_will_create;
1550		} else if (right_gen == gen) {
1551			if (ino < sctx->send_progress)
1552				ret = inode_state_did_delete;
1553			else
1554				ret = inode_state_will_delete;
1555		} else  {
1556			ret = -ENOENT;
1557		}
1558	} else if (!left_ret) {
1559		if (left_gen == gen) {
1560			if (ino < sctx->send_progress)
1561				ret = inode_state_did_create;
1562			else
1563				ret = inode_state_will_create;
1564		} else {
1565			ret = -ENOENT;
1566		}
1567	} else if (!right_ret) {
1568		if (right_gen == gen) {
1569			if (ino < sctx->send_progress)
1570				ret = inode_state_did_delete;
1571			else
1572				ret = inode_state_will_delete;
1573		} else {
1574			ret = -ENOENT;
1575		}
1576	} else {
1577		ret = -ENOENT;
1578	}
1579
1580out:
1581	return ret;
1582}
1583
1584static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
 
1585{
1586	int ret;
1587
1588	ret = get_cur_inode_state(sctx, ino, gen);
 
 
 
1589	if (ret < 0)
1590		goto out;
1591
1592	if (ret == inode_state_no_change ||
1593	    ret == inode_state_did_create ||
1594	    ret == inode_state_will_delete)
1595		ret = 1;
1596	else
1597		ret = 0;
1598
1599out:
1600	return ret;
1601}
1602
1603/*
1604 * Helper function to lookup a dir item in a dir.
1605 */
1606static int lookup_dir_item_inode(struct btrfs_root *root,
1607				 u64 dir, const char *name, int name_len,
1608				 u64 *found_inode,
1609				 u8 *found_type)
1610{
1611	int ret = 0;
1612	struct btrfs_dir_item *di;
1613	struct btrfs_key key;
1614	struct btrfs_path *path;
 
1615
1616	path = alloc_path_for_send();
1617	if (!path)
1618		return -ENOMEM;
1619
1620	di = btrfs_lookup_dir_item(NULL, root, path,
1621			dir, name, name_len, 0);
1622	if (!di) {
1623		ret = -ENOENT;
1624		goto out;
1625	}
1626	if (IS_ERR(di)) {
1627		ret = PTR_ERR(di);
 
1628		goto out;
1629	}
1630	btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
1631	*found_inode = key.objectid;
1632	*found_type = btrfs_dir_type(path->nodes[0], di);
1633
1634out:
1635	btrfs_free_path(path);
1636	return ret;
1637}
1638
1639/*
1640 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
1641 * generation of the parent dir and the name of the dir entry.
1642 */
1643static int get_first_ref(struct btrfs_root *root, u64 ino,
1644			 u64 *dir, u64 *dir_gen, struct fs_path *name)
1645{
1646	int ret;
1647	struct btrfs_key key;
1648	struct btrfs_key found_key;
1649	struct btrfs_path *path;
1650	int len;
1651	u64 parent_dir;
1652
1653	path = alloc_path_for_send();
1654	if (!path)
1655		return -ENOMEM;
1656
1657	key.objectid = ino;
1658	key.type = BTRFS_INODE_REF_KEY;
1659	key.offset = 0;
1660
1661	ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
1662	if (ret < 0)
1663		goto out;
1664	if (!ret)
1665		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1666				path->slots[0]);
1667	if (ret || found_key.objectid != ino ||
1668	    (found_key.type != BTRFS_INODE_REF_KEY &&
1669	     found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1670		ret = -ENOENT;
1671		goto out;
1672	}
1673
1674	if (found_key.type == BTRFS_INODE_REF_KEY) {
1675		struct btrfs_inode_ref *iref;
1676		iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1677				      struct btrfs_inode_ref);
1678		len = btrfs_inode_ref_name_len(path->nodes[0], iref);
1679		ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1680						     (unsigned long)(iref + 1),
1681						     len);
1682		parent_dir = found_key.offset;
1683	} else {
1684		struct btrfs_inode_extref *extref;
1685		extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
1686					struct btrfs_inode_extref);
1687		len = btrfs_inode_extref_name_len(path->nodes[0], extref);
1688		ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
1689					(unsigned long)&extref->name, len);
1690		parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
1691	}
1692	if (ret < 0)
1693		goto out;
1694	btrfs_release_path(path);
1695
1696	ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
1697			NULL, NULL);
1698	if (ret < 0)
1699		goto out;
 
1700
1701	*dir = parent_dir;
1702
1703out:
1704	btrfs_free_path(path);
1705	return ret;
1706}
1707
1708static int is_first_ref(struct btrfs_root *root,
1709			u64 ino, u64 dir,
1710			const char *name, int name_len)
1711{
1712	int ret;
1713	struct fs_path *tmp_name;
1714	u64 tmp_dir;
1715	u64 tmp_dir_gen;
1716
1717	tmp_name = fs_path_alloc();
1718	if (!tmp_name)
1719		return -ENOMEM;
1720
1721	ret = get_first_ref(root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
1722	if (ret < 0)
1723		goto out;
1724
1725	if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1726		ret = 0;
1727		goto out;
1728	}
1729
1730	ret = !memcmp(tmp_name->start, name, name_len);
1731
1732out:
1733	fs_path_free(tmp_name);
1734	return ret;
1735}
1736
1737/*
1738 * Used by process_recorded_refs to determine if a new ref would overwrite an
1739 * already existing ref. In case it detects an overwrite, it returns the
1740 * inode/gen in who_ino/who_gen.
1741 * When an overwrite is detected, process_recorded_refs does proper orphanizing
1742 * to make sure later references to the overwritten inode are possible.
1743 * Orphanizing is however only required for the first ref of an inode.
1744 * process_recorded_refs does an additional is_first_ref check to see if
1745 * orphanizing is really required.
1746 */
1747static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
1748			      const char *name, int name_len,
1749			      u64 *who_ino, u64 *who_gen)
1750{
1751	int ret = 0;
1752	u64 gen;
1753	u64 other_inode = 0;
1754	u8 other_type = 0;
1755
1756	if (!sctx->parent_root)
1757		goto out;
1758
1759	ret = is_inode_existent(sctx, dir, dir_gen);
1760	if (ret <= 0)
1761		goto out;
1762
1763	/*
1764	 * If we have a parent root we need to verify that the parent dir was
1765	 * not delted and then re-created, if it was then we have no overwrite
1766	 * and we can just unlink this entry.
 
 
 
1767	 */
1768	if (sctx->parent_root) {
1769		ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
1770				     NULL, NULL, NULL);
1771		if (ret < 0 && ret != -ENOENT)
1772			goto out;
1773		if (ret) {
1774			ret = 0;
1775			goto out;
1776		}
1777		if (gen != dir_gen)
1778			goto out;
1779	}
1780
1781	ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
1782			&other_inode, &other_type);
1783	if (ret < 0 && ret != -ENOENT)
1784		goto out;
1785	if (ret) {
1786		ret = 0;
1787		goto out;
1788	}
1789
1790	/*
1791	 * Check if the overwritten ref was already processed. If yes, the ref
1792	 * was already unlinked/moved, so we can safely assume that we will not
1793	 * overwrite anything at this point in time.
1794	 */
1795	if (other_inode > sctx->send_progress) {
1796		ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1797				who_gen, NULL, NULL, NULL, NULL);
1798		if (ret < 0)
1799			goto out;
1800
1801		ret = 1;
1802		*who_ino = other_inode;
1803	} else {
1804		ret = 0;
 
1805	}
1806
1807out:
1808	return ret;
1809}
1810
1811/*
1812 * Checks if the ref was overwritten by an already processed inode. This is
1813 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
1814 * thus the orphan name needs be used.
1815 * process_recorded_refs also uses it to avoid unlinking of refs that were
1816 * overwritten.
1817 */
1818static int did_overwrite_ref(struct send_ctx *sctx,
1819			    u64 dir, u64 dir_gen,
1820			    u64 ino, u64 ino_gen,
1821			    const char *name, int name_len)
1822{
1823	int ret = 0;
1824	u64 gen;
1825	u64 ow_inode;
1826	u8 other_type;
 
1827
1828	if (!sctx->parent_root)
1829		goto out;
1830
1831	ret = is_inode_existent(sctx, dir, dir_gen);
1832	if (ret <= 0)
1833		goto out;
 
 
 
 
 
 
 
1834
1835	/* check if the ref was overwritten by another ref */
1836	ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
1837			&ow_inode, &other_type);
1838	if (ret < 0 && ret != -ENOENT)
1839		goto out;
1840	if (ret) {
1841		/* was never and will never be overwritten */
1842		ret = 0;
1843		goto out;
 
1844	}
1845
1846	ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1847			NULL, NULL);
1848	if (ret < 0)
1849		goto out;
1850
1851	if (ow_inode == ino && gen == ino_gen) {
1852		ret = 0;
1853		goto out;
1854	}
1855
1856	/* we know that it is or will be overwritten. check this now */
 
 
 
 
 
1857	if (ow_inode < sctx->send_progress)
1858		ret = 1;
1859	else
1860		ret = 0;
1861
1862out:
1863	return ret;
 
 
 
 
 
 
 
 
 
1864}
1865
1866/*
1867 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
1868 * that got overwritten. This is used by process_recorded_refs to determine
1869 * if it has to use the path as returned by get_cur_path or the orphan name.
1870 */
1871static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
1872{
1873	int ret = 0;
1874	struct fs_path *name = NULL;
1875	u64 dir;
1876	u64 dir_gen;
1877
1878	if (!sctx->parent_root)
1879		goto out;
1880
1881	name = fs_path_alloc();
1882	if (!name)
1883		return -ENOMEM;
1884
1885	ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
1886	if (ret < 0)
1887		goto out;
1888
1889	ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
1890			name->start, fs_path_len(name));
1891
1892out:
1893	fs_path_free(name);
1894	return ret;
1895}
1896
1897/*
1898 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
1899 * so we need to do some special handling in case we have clashes. This function
1900 * takes care of this with the help of name_cache_entry::radix_list.
1901 * In case of error, nce is kfreed.
1902 */
1903static int name_cache_insert(struct send_ctx *sctx,
1904			     struct name_cache_entry *nce)
1905{
1906	int ret = 0;
1907	struct list_head *nce_head;
1908
1909	nce_head = radix_tree_lookup(&sctx->name_cache,
1910			(unsigned long)nce->ino);
1911	if (!nce_head) {
1912		nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
1913		if (!nce_head) {
1914			kfree(nce);
1915			return -ENOMEM;
1916		}
1917		INIT_LIST_HEAD(nce_head);
1918
1919		ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
1920		if (ret < 0) {
1921			kfree(nce_head);
1922			kfree(nce);
1923			return ret;
1924		}
1925	}
1926	list_add_tail(&nce->radix_list, nce_head);
1927	list_add_tail(&nce->list, &sctx->name_cache_list);
1928	sctx->name_cache_size++;
1929
1930	return ret;
1931}
1932
1933static void name_cache_delete(struct send_ctx *sctx,
1934			      struct name_cache_entry *nce)
1935{
1936	struct list_head *nce_head;
1937
1938	nce_head = radix_tree_lookup(&sctx->name_cache,
1939			(unsigned long)nce->ino);
1940	if (!nce_head) {
1941		btrfs_err(sctx->send_root->fs_info,
1942	      "name_cache_delete lookup failed ino %llu cache size %d, leaking memory",
1943			nce->ino, sctx->name_cache_size);
1944	}
1945
1946	list_del(&nce->radix_list);
1947	list_del(&nce->list);
1948	sctx->name_cache_size--;
1949
1950	/*
1951	 * We may not get to the final release of nce_head if the lookup fails
1952	 */
1953	if (nce_head && list_empty(nce_head)) {
1954		radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
1955		kfree(nce_head);
1956	}
1957}
1958
1959static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
1960						    u64 ino, u64 gen)
1961{
1962	struct list_head *nce_head;
1963	struct name_cache_entry *cur;
1964
1965	nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
1966	if (!nce_head)
1967		return NULL;
1968
1969	list_for_each_entry(cur, nce_head, radix_list) {
1970		if (cur->ino == ino && cur->gen == gen)
1971			return cur;
1972	}
1973	return NULL;
1974}
1975
1976/*
1977 * Removes the entry from the list and adds it back to the end. This marks the
1978 * entry as recently used so that name_cache_clean_unused does not remove it.
1979 */
1980static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
1981{
1982	list_del(&nce->list);
1983	list_add_tail(&nce->list, &sctx->name_cache_list);
1984}
1985
1986/*
1987 * Remove some entries from the beginning of name_cache_list.
1988 */
1989static void name_cache_clean_unused(struct send_ctx *sctx)
1990{
1991	struct name_cache_entry *nce;
1992
1993	if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
1994		return;
1995
1996	while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
1997		nce = list_entry(sctx->name_cache_list.next,
1998				struct name_cache_entry, list);
1999		name_cache_delete(sctx, nce);
2000		kfree(nce);
2001	}
2002}
2003
2004static void name_cache_free(struct send_ctx *sctx)
2005{
2006	struct name_cache_entry *nce;
2007
2008	while (!list_empty(&sctx->name_cache_list)) {
2009		nce = list_entry(sctx->name_cache_list.next,
2010				struct name_cache_entry, list);
2011		name_cache_delete(sctx, nce);
2012		kfree(nce);
2013	}
2014}
2015
2016/*
2017 * Used by get_cur_path for each ref up to the root.
2018 * Returns 0 if it succeeded.
2019 * Returns 1 if the inode is not existent or got overwritten. In that case, the
2020 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
2021 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
2022 * Returns <0 in case of error.
2023 */
2024static int __get_cur_name_and_parent(struct send_ctx *sctx,
2025				     u64 ino, u64 gen,
2026				     u64 *parent_ino,
2027				     u64 *parent_gen,
2028				     struct fs_path *dest)
2029{
2030	int ret;
2031	int nce_ret;
2032	struct btrfs_path *path = NULL;
2033	struct name_cache_entry *nce = NULL;
2034
2035	/*
2036	 * First check if we already did a call to this function with the same
2037	 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
2038	 * return the cached result.
2039	 */
2040	nce = name_cache_search(sctx, ino, gen);
2041	if (nce) {
2042		if (ino < sctx->send_progress && nce->need_later_update) {
2043			name_cache_delete(sctx, nce);
2044			kfree(nce);
2045			nce = NULL;
2046		} else {
2047			name_cache_used(sctx, nce);
2048			*parent_ino = nce->parent_ino;
2049			*parent_gen = nce->parent_gen;
2050			ret = fs_path_add(dest, nce->name, nce->name_len);
2051			if (ret < 0)
2052				goto out;
2053			ret = nce->ret;
2054			goto out;
2055		}
2056	}
2057
2058	path = alloc_path_for_send();
2059	if (!path)
2060		return -ENOMEM;
2061
2062	/*
2063	 * If the inode is not existent yet, add the orphan name and return 1.
2064	 * This should only happen for the parent dir that we determine in
2065	 * __record_new_ref
2066	 */
2067	ret = is_inode_existent(sctx, ino, gen);
2068	if (ret < 0)
2069		goto out;
2070
2071	if (!ret) {
2072		ret = gen_unique_name(sctx, ino, gen, dest);
2073		if (ret < 0)
2074			goto out;
2075		ret = 1;
2076		goto out_cache;
2077	}
2078
2079	/*
2080	 * Depending on whether the inode was already processed or not, use
2081	 * send_root or parent_root for ref lookup.
2082	 */
2083	if (ino < sctx->send_progress)
2084		ret = get_first_ref(sctx->send_root, ino,
2085				    parent_ino, parent_gen, dest);
2086	else
2087		ret = get_first_ref(sctx->parent_root, ino,
2088				    parent_ino, parent_gen, dest);
2089	if (ret < 0)
2090		goto out;
2091
2092	/*
2093	 * Check if the ref was overwritten by an inode's ref that was processed
2094	 * earlier. If yes, treat as orphan and return 1.
2095	 */
2096	ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
2097			dest->start, dest->end - dest->start);
2098	if (ret < 0)
2099		goto out;
2100	if (ret) {
2101		fs_path_reset(dest);
2102		ret = gen_unique_name(sctx, ino, gen, dest);
2103		if (ret < 0)
2104			goto out;
2105		ret = 1;
2106	}
2107
2108out_cache:
2109	/*
2110	 * Store the result of the lookup in the name cache.
2111	 */
2112	nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS);
2113	if (!nce) {
2114		ret = -ENOMEM;
2115		goto out;
2116	}
2117
2118	nce->ino = ino;
2119	nce->gen = gen;
2120	nce->parent_ino = *parent_ino;
2121	nce->parent_gen = *parent_gen;
2122	nce->name_len = fs_path_len(dest);
2123	nce->ret = ret;
2124	strcpy(nce->name, dest->start);
2125
2126	if (ino < sctx->send_progress)
2127		nce->need_later_update = 0;
2128	else
2129		nce->need_later_update = 1;
2130
2131	nce_ret = name_cache_insert(sctx, nce);
2132	if (nce_ret < 0)
 
2133		ret = nce_ret;
2134	name_cache_clean_unused(sctx);
2135
2136out:
2137	btrfs_free_path(path);
2138	return ret;
2139}
2140
2141/*
2142 * Magic happens here. This function returns the first ref to an inode as it
2143 * would look like while receiving the stream at this point in time.
2144 * We walk the path up to the root. For every inode in between, we check if it
2145 * was already processed/sent. If yes, we continue with the parent as found
2146 * in send_root. If not, we continue with the parent as found in parent_root.
2147 * If we encounter an inode that was deleted at this point in time, we use the
2148 * inodes "orphan" name instead of the real name and stop. Same with new inodes
2149 * that were not created yet and overwritten inodes/refs.
2150 *
2151 * When do we have have orphan inodes:
2152 * 1. When an inode is freshly created and thus no valid refs are available yet
2153 * 2. When a directory lost all it's refs (deleted) but still has dir items
2154 *    inside which were not processed yet (pending for move/delete). If anyone
2155 *    tried to get the path to the dir items, it would get a path inside that
2156 *    orphan directory.
2157 * 3. When an inode is moved around or gets new links, it may overwrite the ref
2158 *    of an unprocessed inode. If in that case the first ref would be
2159 *    overwritten, the overwritten inode gets "orphanized". Later when we
2160 *    process this overwritten inode, it is restored at a new place by moving
2161 *    the orphan inode.
2162 *
2163 * sctx->send_progress tells this function at which point in time receiving
2164 * would be.
2165 */
2166static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
2167			struct fs_path *dest)
2168{
2169	int ret = 0;
2170	struct fs_path *name = NULL;
2171	u64 parent_inode = 0;
2172	u64 parent_gen = 0;
2173	int stop = 0;
2174
2175	name = fs_path_alloc();
2176	if (!name) {
2177		ret = -ENOMEM;
2178		goto out;
2179	}
2180
2181	dest->reversed = 1;
2182	fs_path_reset(dest);
2183
2184	while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
 
 
2185		fs_path_reset(name);
2186
2187		if (is_waiting_for_rm(sctx, ino)) {
2188			ret = gen_unique_name(sctx, ino, gen, name);
2189			if (ret < 0)
2190				goto out;
2191			ret = fs_path_add_path(dest, name);
2192			break;
2193		}
2194
2195		if (is_waiting_for_move(sctx, ino)) {
 
 
 
 
2196			ret = get_first_ref(sctx->parent_root, ino,
2197					    &parent_inode, &parent_gen, name);
2198		} else {
2199			ret = __get_cur_name_and_parent(sctx, ino, gen,
2200							&parent_inode,
2201							&parent_gen, name);
2202			if (ret)
2203				stop = 1;
2204		}
2205
2206		if (ret < 0)
2207			goto out;
2208
2209		ret = fs_path_add_path(dest, name);
2210		if (ret < 0)
2211			goto out;
2212
2213		ino = parent_inode;
2214		gen = parent_gen;
2215	}
2216
2217out:
2218	fs_path_free(name);
2219	if (!ret)
2220		fs_path_unreverse(dest);
2221	return ret;
2222}
2223
2224/*
2225 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
2226 */
2227static int send_subvol_begin(struct send_ctx *sctx)
2228{
2229	int ret;
2230	struct btrfs_root *send_root = sctx->send_root;
2231	struct btrfs_root *parent_root = sctx->parent_root;
2232	struct btrfs_path *path;
2233	struct btrfs_key key;
2234	struct btrfs_root_ref *ref;
2235	struct extent_buffer *leaf;
2236	char *name = NULL;
2237	int namelen;
2238
2239	path = btrfs_alloc_path();
2240	if (!path)
2241		return -ENOMEM;
2242
2243	name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS);
2244	if (!name) {
2245		btrfs_free_path(path);
2246		return -ENOMEM;
2247	}
2248
2249	key.objectid = send_root->objectid;
2250	key.type = BTRFS_ROOT_BACKREF_KEY;
2251	key.offset = 0;
2252
2253	ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
2254				&key, path, 1, 0);
2255	if (ret < 0)
2256		goto out;
2257	if (ret) {
2258		ret = -ENOENT;
2259		goto out;
2260	}
2261
2262	leaf = path->nodes[0];
2263	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2264	if (key.type != BTRFS_ROOT_BACKREF_KEY ||
2265	    key.objectid != send_root->objectid) {
2266		ret = -ENOENT;
2267		goto out;
2268	}
2269	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
2270	namelen = btrfs_root_ref_name_len(leaf, ref);
2271	read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
2272	btrfs_release_path(path);
2273
2274	if (parent_root) {
2275		ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
2276		if (ret < 0)
2277			goto out;
2278	} else {
2279		ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
2280		if (ret < 0)
2281			goto out;
2282	}
2283
2284	TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
2285	TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
2286			sctx->send_root->root_item.uuid);
 
 
 
 
 
 
2287	TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2288		    le64_to_cpu(sctx->send_root->root_item.ctransid));
2289	if (parent_root) {
2290		TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
2291				sctx->parent_root->root_item.uuid);
 
 
 
 
2292		TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2293			    le64_to_cpu(sctx->parent_root->root_item.ctransid));
2294	}
2295
2296	ret = send_cmd(sctx);
2297
2298tlv_put_failure:
2299out:
2300	btrfs_free_path(path);
2301	kfree(name);
2302	return ret;
2303}
2304
2305static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
2306{
 
2307	int ret = 0;
2308	struct fs_path *p;
2309
2310verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino, size);
2311
2312	p = fs_path_alloc();
2313	if (!p)
2314		return -ENOMEM;
2315
2316	ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
2317	if (ret < 0)
2318		goto out;
2319
2320	ret = get_cur_path(sctx, ino, gen, p);
2321	if (ret < 0)
2322		goto out;
2323	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2324	TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);
2325
2326	ret = send_cmd(sctx);
2327
2328tlv_put_failure:
2329out:
2330	fs_path_free(p);
2331	return ret;
2332}
2333
2334static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
2335{
 
2336	int ret = 0;
2337	struct fs_path *p;
2338
2339verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino, mode);
2340
2341	p = fs_path_alloc();
2342	if (!p)
2343		return -ENOMEM;
2344
2345	ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
2346	if (ret < 0)
2347		goto out;
2348
2349	ret = get_cur_path(sctx, ino, gen, p);
2350	if (ret < 0)
2351		goto out;
2352	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2353	TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);
2354
2355	ret = send_cmd(sctx);
2356
2357tlv_put_failure:
2358out:
2359	fs_path_free(p);
2360	return ret;
2361}
2362
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2363static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
2364{
 
2365	int ret = 0;
2366	struct fs_path *p;
2367
2368verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino, uid, gid);
 
2369
2370	p = fs_path_alloc();
2371	if (!p)
2372		return -ENOMEM;
2373
2374	ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
2375	if (ret < 0)
2376		goto out;
2377
2378	ret = get_cur_path(sctx, ino, gen, p);
2379	if (ret < 0)
2380		goto out;
2381	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2382	TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
2383	TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);
2384
2385	ret = send_cmd(sctx);
2386
2387tlv_put_failure:
2388out:
2389	fs_path_free(p);
2390	return ret;
2391}
2392
2393static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
2394{
 
2395	int ret = 0;
2396	struct fs_path *p = NULL;
2397	struct btrfs_inode_item *ii;
2398	struct btrfs_path *path = NULL;
2399	struct extent_buffer *eb;
2400	struct btrfs_key key;
2401	int slot;
2402
2403verbose_printk("btrfs: send_utimes %llu\n", ino);
2404
2405	p = fs_path_alloc();
2406	if (!p)
2407		return -ENOMEM;
2408
2409	path = alloc_path_for_send();
2410	if (!path) {
2411		ret = -ENOMEM;
2412		goto out;
2413	}
2414
2415	key.objectid = ino;
2416	key.type = BTRFS_INODE_ITEM_KEY;
2417	key.offset = 0;
2418	ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
 
 
2419	if (ret < 0)
2420		goto out;
2421
2422	eb = path->nodes[0];
2423	slot = path->slots[0];
2424	ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
2425
2426	ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
2427	if (ret < 0)
2428		goto out;
2429
2430	ret = get_cur_path(sctx, ino, gen, p);
2431	if (ret < 0)
2432		goto out;
2433	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2434	TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb,
2435			btrfs_inode_atime(ii));
2436	TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb,
2437			btrfs_inode_mtime(ii));
2438	TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb,
2439			btrfs_inode_ctime(ii));
2440	/* TODO Add otime support when the otime patches get into upstream */
2441
2442	ret = send_cmd(sctx);
2443
2444tlv_put_failure:
2445out:
2446	fs_path_free(p);
2447	btrfs_free_path(path);
2448	return ret;
2449}
2450
2451/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2452 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
2453 * a valid path yet because we did not process the refs yet. So, the inode
2454 * is created as orphan.
2455 */
2456static int send_create_inode(struct send_ctx *sctx, u64 ino)
2457{
 
2458	int ret = 0;
2459	struct fs_path *p;
2460	int cmd;
 
2461	u64 gen;
2462	u64 mode;
2463	u64 rdev;
2464
2465verbose_printk("btrfs: send_create_inode %llu\n", ino);
2466
2467	p = fs_path_alloc();
2468	if (!p)
2469		return -ENOMEM;
2470
2471	if (ino != sctx->cur_ino) {
2472		ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode,
2473				     NULL, NULL, &rdev);
2474		if (ret < 0)
2475			goto out;
 
 
 
2476	} else {
2477		gen = sctx->cur_inode_gen;
2478		mode = sctx->cur_inode_mode;
2479		rdev = sctx->cur_inode_rdev;
2480	}
2481
2482	if (S_ISREG(mode)) {
2483		cmd = BTRFS_SEND_C_MKFILE;
2484	} else if (S_ISDIR(mode)) {
2485		cmd = BTRFS_SEND_C_MKDIR;
2486	} else if (S_ISLNK(mode)) {
2487		cmd = BTRFS_SEND_C_SYMLINK;
2488	} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2489		cmd = BTRFS_SEND_C_MKNOD;
2490	} else if (S_ISFIFO(mode)) {
2491		cmd = BTRFS_SEND_C_MKFIFO;
2492	} else if (S_ISSOCK(mode)) {
2493		cmd = BTRFS_SEND_C_MKSOCK;
2494	} else {
2495		printk(KERN_WARNING "btrfs: unexpected inode type %o",
2496				(int)(mode & S_IFMT));
2497		ret = -ENOTSUPP;
2498		goto out;
2499	}
2500
2501	ret = begin_cmd(sctx, cmd);
2502	if (ret < 0)
2503		goto out;
2504
2505	ret = gen_unique_name(sctx, ino, gen, p);
2506	if (ret < 0)
2507		goto out;
2508
2509	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2510	TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2511
2512	if (S_ISLNK(mode)) {
2513		fs_path_reset(p);
2514		ret = read_symlink(sctx->send_root, ino, p);
2515		if (ret < 0)
2516			goto out;
2517		TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
2518	} else if (S_ISCHR(mode) || S_ISBLK(mode) ||
2519		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
2520		TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
2521		TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2522	}
2523
2524	ret = send_cmd(sctx);
2525	if (ret < 0)
2526		goto out;
2527
2528
2529tlv_put_failure:
2530out:
2531	fs_path_free(p);
2532	return ret;
2533}
2534
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2535/*
2536 * We need some special handling for inodes that get processed before the parent
2537 * directory got created. See process_recorded_refs for details.
2538 * This function does the check if we already created the dir out of order.
2539 */
2540static int did_create_dir(struct send_ctx *sctx, u64 dir)
2541{
2542	int ret = 0;
 
2543	struct btrfs_path *path = NULL;
2544	struct btrfs_key key;
2545	struct btrfs_key found_key;
2546	struct btrfs_key di_key;
2547	struct extent_buffer *eb;
2548	struct btrfs_dir_item *di;
2549	int slot;
 
 
2550
2551	path = alloc_path_for_send();
2552	if (!path) {
2553		ret = -ENOMEM;
2554		goto out;
2555	}
2556
2557	key.objectid = dir;
2558	key.type = BTRFS_DIR_INDEX_KEY;
2559	key.offset = 0;
2560	ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
2561	if (ret < 0)
2562		goto out;
2563
2564	while (1) {
2565		eb = path->nodes[0];
2566		slot = path->slots[0];
2567		if (slot >= btrfs_header_nritems(eb)) {
2568			ret = btrfs_next_leaf(sctx->send_root, path);
2569			if (ret < 0) {
2570				goto out;
2571			} else if (ret > 0) {
2572				ret = 0;
2573				break;
2574			}
2575			continue;
2576		}
2577
2578		btrfs_item_key_to_cpu(eb, &found_key, slot);
2579		if (found_key.objectid != key.objectid ||
2580		    found_key.type != key.type) {
2581			ret = 0;
2582			goto out;
2583		}
2584
2585		di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2586		btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2587
2588		if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
2589		    di_key.objectid < sctx->send_progress) {
2590			ret = 1;
2591			goto out;
 
2592		}
2593
2594		path->slots[0]++;
2595	}
 
 
 
2596
2597out:
2598	btrfs_free_path(path);
2599	return ret;
2600}
2601
2602/*
2603 * Only creates the inode if it is:
2604 * 1. Not a directory
2605 * 2. Or a directory which was not created already due to out of order
2606 *    directories. See did_create_dir and process_recorded_refs for details.
2607 */
2608static int send_create_inode_if_needed(struct send_ctx *sctx)
2609{
2610	int ret;
2611
2612	if (S_ISDIR(sctx->cur_inode_mode)) {
2613		ret = did_create_dir(sctx, sctx->cur_ino);
2614		if (ret < 0)
2615			goto out;
2616		if (ret) {
2617			ret = 0;
2618			goto out;
2619		}
2620	}
2621
2622	ret = send_create_inode(sctx, sctx->cur_ino);
2623	if (ret < 0)
2624		goto out;
2625
2626out:
 
 
2627	return ret;
2628}
2629
2630struct recorded_ref {
2631	struct list_head list;
2632	char *dir_path;
2633	char *name;
2634	struct fs_path *full_path;
2635	u64 dir;
2636	u64 dir_gen;
2637	int dir_path_len;
2638	int name_len;
 
 
2639};
2640
2641/*
2642 * We need to process new refs before deleted refs, but compare_tree gives us
2643 * everything mixed. So we first record all refs and later process them.
2644 * This function is a helper to record one ref.
2645 */
2646static int __record_ref(struct list_head *head, u64 dir,
2647		      u64 dir_gen, struct fs_path *path)
2648{
2649	struct recorded_ref *ref;
2650
2651	ref = kmalloc(sizeof(*ref), GFP_NOFS);
2652	if (!ref)
2653		return -ENOMEM;
 
 
 
 
2654
2655	ref->dir = dir;
2656	ref->dir_gen = dir_gen;
2657	ref->full_path = path;
 
 
 
 
 
 
 
2658
 
 
 
2659	ref->name = (char *)kbasename(ref->full_path->start);
2660	ref->name_len = ref->full_path->end - ref->name;
2661	ref->dir_path = ref->full_path->start;
2662	if (ref->name == ref->full_path->start)
2663		ref->dir_path_len = 0;
2664	else
2665		ref->dir_path_len = ref->full_path->end -
2666				ref->full_path->start - 1 - ref->name_len;
2667
2668	list_add_tail(&ref->list, head);
2669	return 0;
2670}
2671
2672static int dup_ref(struct recorded_ref *ref, struct list_head *list)
2673{
2674	struct recorded_ref *new;
2675
2676	new = kmalloc(sizeof(*ref), GFP_NOFS);
2677	if (!new)
2678		return -ENOMEM;
2679
2680	new->dir = ref->dir;
2681	new->dir_gen = ref->dir_gen;
2682	new->full_path = NULL;
2683	INIT_LIST_HEAD(&new->list);
2684	list_add_tail(&new->list, list);
2685	return 0;
2686}
2687
2688static void __free_recorded_refs(struct list_head *head)
2689{
2690	struct recorded_ref *cur;
2691
2692	while (!list_empty(head)) {
2693		cur = list_entry(head->next, struct recorded_ref, list);
2694		fs_path_free(cur->full_path);
2695		list_del(&cur->list);
2696		kfree(cur);
2697	}
2698}
2699
2700static void free_recorded_refs(struct send_ctx *sctx)
2701{
2702	__free_recorded_refs(&sctx->new_refs);
2703	__free_recorded_refs(&sctx->deleted_refs);
2704}
2705
2706/*
2707 * Renames/moves a file/dir to its orphan name. Used when the first
2708 * ref of an unprocessed inode gets overwritten and for all non empty
2709 * directories.
2710 */
2711static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
2712			  struct fs_path *path)
2713{
2714	int ret;
2715	struct fs_path *orphan;
2716
2717	orphan = fs_path_alloc();
2718	if (!orphan)
2719		return -ENOMEM;
2720
2721	ret = gen_unique_name(sctx, ino, gen, orphan);
2722	if (ret < 0)
2723		goto out;
2724
2725	ret = send_rename(sctx, path, orphan);
2726
2727out:
2728	fs_path_free(orphan);
2729	return ret;
2730}
2731
2732static struct orphan_dir_info *
2733add_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2734{
2735	struct rb_node **p = &sctx->orphan_dirs.rb_node;
2736	struct rb_node *parent = NULL;
2737	struct orphan_dir_info *entry, *odi;
2738
2739	odi = kmalloc(sizeof(*odi), GFP_NOFS);
2740	if (!odi)
2741		return ERR_PTR(-ENOMEM);
2742	odi->ino = dir_ino;
2743	odi->gen = 0;
2744
2745	while (*p) {
2746		parent = *p;
2747		entry = rb_entry(parent, struct orphan_dir_info, node);
2748		if (dir_ino < entry->ino) {
2749			p = &(*p)->rb_left;
2750		} else if (dir_ino > entry->ino) {
2751			p = &(*p)->rb_right;
2752		} else {
2753			kfree(odi);
 
 
 
2754			return entry;
2755		}
2756	}
2757
 
 
 
 
 
 
 
 
2758	rb_link_node(&odi->node, parent, p);
2759	rb_insert_color(&odi->node, &sctx->orphan_dirs);
2760	return odi;
2761}
2762
2763static struct orphan_dir_info *
2764get_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
2765{
2766	struct rb_node *n = sctx->orphan_dirs.rb_node;
2767	struct orphan_dir_info *entry;
2768
2769	while (n) {
2770		entry = rb_entry(n, struct orphan_dir_info, node);
2771		if (dir_ino < entry->ino)
2772			n = n->rb_left;
2773		else if (dir_ino > entry->ino)
2774			n = n->rb_right;
 
 
 
 
2775		else
2776			return entry;
2777	}
2778	return NULL;
2779}
2780
2781static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino)
2782{
2783	struct orphan_dir_info *odi = get_orphan_dir_info(sctx, dir_ino);
2784
2785	return odi != NULL;
2786}
2787
2788static void free_orphan_dir_info(struct send_ctx *sctx,
2789				 struct orphan_dir_info *odi)
2790{
2791	if (!odi)
2792		return;
2793	rb_erase(&odi->node, &sctx->orphan_dirs);
2794	kfree(odi);
2795}
2796
2797/*
2798 * Returns 1 if a directory can be removed at this point in time.
2799 * We check this by iterating all dir items and checking if the inode behind
2800 * the dir item was already processed.
2801 */
2802static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
2803		     u64 send_progress)
2804{
2805	int ret = 0;
 
2806	struct btrfs_root *root = sctx->parent_root;
2807	struct btrfs_path *path;
2808	struct btrfs_key key;
2809	struct btrfs_key found_key;
2810	struct btrfs_key loc;
2811	struct btrfs_dir_item *di;
 
 
 
2812
2813	/*
2814	 * Don't try to rmdir the top/root subvolume dir.
2815	 */
2816	if (dir == BTRFS_FIRST_FREE_OBJECTID)
2817		return 0;
2818
 
 
 
 
2819	path = alloc_path_for_send();
2820	if (!path)
2821		return -ENOMEM;
2822
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2823	key.objectid = dir;
2824	key.type = BTRFS_DIR_INDEX_KEY;
2825	key.offset = 0;
2826	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2827	if (ret < 0)
2828		goto out;
2829
2830	while (1) {
2831		struct waiting_dir_move *dm;
2832
2833		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
2834			ret = btrfs_next_leaf(root, path);
2835			if (ret < 0)
2836				goto out;
2837			else if (ret > 0)
2838				break;
2839			continue;
2840		}
2841		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2842				      path->slots[0]);
2843		if (found_key.objectid != key.objectid ||
2844		    found_key.type != key.type)
2845			break;
2846
2847		di = btrfs_item_ptr(path->nodes[0], path->slots[0],
2848				struct btrfs_dir_item);
2849		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);
2850
 
 
 
2851		dm = get_waiting_dir_move(sctx, loc.objectid);
2852		if (dm) {
2853			struct orphan_dir_info *odi;
2854
2855			odi = add_orphan_dir_info(sctx, dir);
2856			if (IS_ERR(odi)) {
2857				ret = PTR_ERR(odi);
2858				goto out;
2859			}
2860			odi->gen = dir_gen;
2861			dm->rmdir_ino = dir;
 
2862			ret = 0;
2863			goto out;
2864		}
2865
2866		if (loc.objectid > send_progress) {
2867			ret = 0;
2868			goto out;
2869		}
2870
2871		path->slots[0]++;
2872	}
 
 
 
 
 
2873
2874	ret = 1;
2875
2876out:
2877	btrfs_free_path(path);
2878	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2879}
2880
2881static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
2882{
2883	struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino);
2884
2885	return entry != NULL;
2886}
2887
2888static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2889{
2890	struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
2891	struct rb_node *parent = NULL;
2892	struct waiting_dir_move *entry, *dm;
2893
2894	dm = kmalloc(sizeof(*dm), GFP_NOFS);
2895	if (!dm)
2896		return -ENOMEM;
2897	dm->ino = ino;
2898	dm->rmdir_ino = 0;
 
 
2899
2900	while (*p) {
2901		parent = *p;
2902		entry = rb_entry(parent, struct waiting_dir_move, node);
2903		if (ino < entry->ino) {
2904			p = &(*p)->rb_left;
2905		} else if (ino > entry->ino) {
2906			p = &(*p)->rb_right;
2907		} else {
2908			kfree(dm);
2909			return -EEXIST;
2910		}
2911	}
2912
2913	rb_link_node(&dm->node, parent, p);
2914	rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
2915	return 0;
2916}
2917
2918static struct waiting_dir_move *
2919get_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2920{
2921	struct rb_node *n = sctx->waiting_dir_moves.rb_node;
2922	struct waiting_dir_move *entry;
2923
2924	while (n) {
2925		entry = rb_entry(n, struct waiting_dir_move, node);
2926		if (ino < entry->ino)
2927			n = n->rb_left;
2928		else if (ino > entry->ino)
2929			n = n->rb_right;
2930		else
2931			return entry;
2932	}
2933	return NULL;
2934}
2935
2936static void free_waiting_dir_move(struct send_ctx *sctx,
2937				  struct waiting_dir_move *dm)
2938{
2939	if (!dm)
2940		return;
2941	rb_erase(&dm->node, &sctx->waiting_dir_moves);
2942	kfree(dm);
2943}
2944
2945static int add_pending_dir_move(struct send_ctx *sctx,
2946				u64 ino,
2947				u64 ino_gen,
2948				u64 parent_ino)
 
 
 
2949{
2950	struct rb_node **p = &sctx->pending_dir_moves.rb_node;
2951	struct rb_node *parent = NULL;
2952	struct pending_dir_move *entry = NULL, *pm;
2953	struct recorded_ref *cur;
2954	int exists = 0;
2955	int ret;
2956
2957	pm = kmalloc(sizeof(*pm), GFP_NOFS);
2958	if (!pm)
2959		return -ENOMEM;
2960	pm->parent_ino = parent_ino;
2961	pm->ino = ino;
2962	pm->gen = ino_gen;
2963	INIT_LIST_HEAD(&pm->list);
2964	INIT_LIST_HEAD(&pm->update_refs);
2965	RB_CLEAR_NODE(&pm->node);
2966
2967	while (*p) {
2968		parent = *p;
2969		entry = rb_entry(parent, struct pending_dir_move, node);
2970		if (parent_ino < entry->parent_ino) {
2971			p = &(*p)->rb_left;
2972		} else if (parent_ino > entry->parent_ino) {
2973			p = &(*p)->rb_right;
2974		} else {
2975			exists = 1;
2976			break;
2977		}
2978	}
2979
2980	list_for_each_entry(cur, &sctx->deleted_refs, list) {
2981		ret = dup_ref(cur, &pm->update_refs);
2982		if (ret < 0)
2983			goto out;
2984	}
2985	list_for_each_entry(cur, &sctx->new_refs, list) {
2986		ret = dup_ref(cur, &pm->update_refs);
2987		if (ret < 0)
2988			goto out;
2989	}
2990
2991	ret = add_waiting_dir_move(sctx, pm->ino);
2992	if (ret)
2993		goto out;
2994
2995	if (exists) {
2996		list_add_tail(&pm->list, &entry->list);
2997	} else {
2998		rb_link_node(&pm->node, parent, p);
2999		rb_insert_color(&pm->node, &sctx->pending_dir_moves);
3000	}
3001	ret = 0;
3002out:
3003	if (ret) {
3004		__free_recorded_refs(&pm->update_refs);
3005		kfree(pm);
3006	}
3007	return ret;
3008}
3009
3010static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
3011						      u64 parent_ino)
3012{
3013	struct rb_node *n = sctx->pending_dir_moves.rb_node;
3014	struct pending_dir_move *entry;
3015
3016	while (n) {
3017		entry = rb_entry(n, struct pending_dir_move, node);
3018		if (parent_ino < entry->parent_ino)
3019			n = n->rb_left;
3020		else if (parent_ino > entry->parent_ino)
3021			n = n->rb_right;
3022		else
3023			return entry;
3024	}
3025	return NULL;
3026}
3027
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3028static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
3029{
3030	struct fs_path *from_path = NULL;
3031	struct fs_path *to_path = NULL;
3032	struct fs_path *name = NULL;
3033	u64 orig_progress = sctx->send_progress;
3034	struct recorded_ref *cur;
3035	u64 parent_ino, parent_gen;
3036	struct waiting_dir_move *dm = NULL;
3037	u64 rmdir_ino = 0;
 
 
 
3038	int ret;
3039
3040	name = fs_path_alloc();
3041	from_path = fs_path_alloc();
3042	if (!name || !from_path) {
3043		ret = -ENOMEM;
3044		goto out;
3045	}
3046
3047	dm = get_waiting_dir_move(sctx, pm->ino);
3048	ASSERT(dm);
3049	rmdir_ino = dm->rmdir_ino;
 
 
3050	free_waiting_dir_move(sctx, dm);
3051
3052	ret = get_first_ref(sctx->parent_root, pm->ino,
3053			    &parent_ino, &parent_gen, name);
3054	if (ret < 0)
3055		goto out;
3056
3057	if (parent_ino == sctx->cur_ino) {
3058		/* child only renamed, not moved */
3059		ASSERT(parent_gen == sctx->cur_inode_gen);
3060		ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3061				   from_path);
3062		if (ret < 0)
3063			goto out;
3064		ret = fs_path_add_path(from_path, name);
3065		if (ret < 0)
3066			goto out;
3067	} else {
3068		/* child moved and maybe renamed too */
3069		sctx->send_progress = pm->ino;
3070		ret = get_cur_path(sctx, pm->ino, pm->gen, from_path);
3071		if (ret < 0)
3072			goto out;
 
3073	}
3074
3075	fs_path_free(name);
3076	name = NULL;
3077
3078	to_path = fs_path_alloc();
3079	if (!to_path) {
3080		ret = -ENOMEM;
3081		goto out;
3082	}
3083
3084	sctx->send_progress = sctx->cur_ino + 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3085	ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
3086	if (ret < 0)
3087		goto out;
3088
3089	ret = send_rename(sctx, from_path, to_path);
3090	if (ret < 0)
3091		goto out;
3092
3093	if (rmdir_ino) {
3094		struct orphan_dir_info *odi;
 
3095
3096		odi = get_orphan_dir_info(sctx, rmdir_ino);
3097		if (!odi) {
3098			/* already deleted */
3099			goto finish;
3100		}
3101		ret = can_rmdir(sctx, rmdir_ino, odi->gen, sctx->cur_ino + 1);
 
 
3102		if (ret < 0)
3103			goto out;
3104		if (!ret)
3105			goto finish;
3106
3107		name = fs_path_alloc();
3108		if (!name) {
3109			ret = -ENOMEM;
3110			goto out;
3111		}
3112		ret = get_cur_path(sctx, rmdir_ino, odi->gen, name);
3113		if (ret < 0)
3114			goto out;
3115		ret = send_rmdir(sctx, name);
3116		if (ret < 0)
3117			goto out;
3118		free_orphan_dir_info(sctx, odi);
3119	}
3120
3121finish:
3122	ret = send_utimes(sctx, pm->ino, pm->gen);
3123	if (ret < 0)
3124		goto out;
3125
3126	/*
3127	 * After rename/move, need to update the utimes of both new parent(s)
3128	 * and old parent(s).
3129	 */
3130	list_for_each_entry(cur, &pm->update_refs, list) {
3131		if (cur->dir == rmdir_ino)
 
 
 
 
 
3132			continue;
3133		ret = send_utimes(sctx, cur->dir, cur->dir_gen);
 
 
 
 
3134		if (ret < 0)
3135			goto out;
3136	}
3137
3138out:
3139	fs_path_free(name);
3140	fs_path_free(from_path);
3141	fs_path_free(to_path);
3142	sctx->send_progress = orig_progress;
3143
3144	return ret;
3145}
3146
3147static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
3148{
3149	if (!list_empty(&m->list))
3150		list_del(&m->list);
3151	if (!RB_EMPTY_NODE(&m->node))
3152		rb_erase(&m->node, &sctx->pending_dir_moves);
3153	__free_recorded_refs(&m->update_refs);
3154	kfree(m);
3155}
3156
3157static void tail_append_pending_moves(struct pending_dir_move *moves,
 
3158				      struct list_head *stack)
3159{
3160	if (list_empty(&moves->list)) {
3161		list_add_tail(&moves->list, stack);
3162	} else {
3163		LIST_HEAD(list);
3164		list_splice_init(&moves->list, &list);
3165		list_add_tail(&moves->list, stack);
3166		list_splice_tail(&list, stack);
3167	}
 
 
 
 
3168}
3169
3170static int apply_children_dir_moves(struct send_ctx *sctx)
3171{
3172	struct pending_dir_move *pm;
3173	struct list_head stack;
3174	u64 parent_ino = sctx->cur_ino;
3175	int ret = 0;
3176
3177	pm = get_pending_dir_moves(sctx, parent_ino);
3178	if (!pm)
3179		return 0;
3180
3181	INIT_LIST_HEAD(&stack);
3182	tail_append_pending_moves(pm, &stack);
3183
3184	while (!list_empty(&stack)) {
3185		pm = list_first_entry(&stack, struct pending_dir_move, list);
3186		parent_ino = pm->ino;
3187		ret = apply_dir_move(sctx, pm);
3188		free_pending_move(sctx, pm);
3189		if (ret)
3190			goto out;
3191		pm = get_pending_dir_moves(sctx, parent_ino);
3192		if (pm)
3193			tail_append_pending_moves(pm, &stack);
3194	}
3195	return 0;
3196
3197out:
3198	while (!list_empty(&stack)) {
3199		pm = list_first_entry(&stack, struct pending_dir_move, list);
3200		free_pending_move(sctx, pm);
3201	}
3202	return ret;
3203}
3204
3205static int wait_for_parent_move(struct send_ctx *sctx,
3206				struct recorded_ref *parent_ref)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3207{
3208	int ret;
3209	u64 ino = parent_ref->dir;
3210	u64 parent_ino_before, parent_ino_after;
3211	u64 old_gen;
3212	struct fs_path *path_before = NULL;
3213	struct fs_path *path_after = NULL;
3214	int len1, len2;
3215	int register_upper_dirs;
3216	u64 gen;
3217
3218	if (is_waiting_for_move(sctx, ino))
3219		return 1;
3220
3221	if (parent_ref->dir <= sctx->cur_ino)
3222		return 0;
3223
3224	ret = get_inode_info(sctx->parent_root, ino, NULL, &old_gen,
3225			     NULL, NULL, NULL, NULL);
3226	if (ret == -ENOENT)
3227		return 0;
3228	else if (ret < 0)
3229		return ret;
3230
3231	if (parent_ref->dir_gen != old_gen)
3232		return 0;
 
3233
3234	path_before = fs_path_alloc();
3235	if (!path_before)
3236		return -ENOMEM;
 
 
 
 
3237
3238	ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
3239			    NULL, path_before);
3240	if (ret == -ENOENT) {
3241		ret = 0;
3242		goto out;
3243	} else if (ret < 0) {
 
 
 
 
 
 
 
 
 
 
 
3244		goto out;
3245	}
3246
3247	path_after = fs_path_alloc();
3248	if (!path_after) {
3249		ret = -ENOMEM;
 
 
 
 
3250		goto out;
3251	}
3252
3253	ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3254			    &gen, path_after);
3255	if (ret == -ENOENT) {
3256		ret = 0;
3257		goto out;
3258	} else if (ret < 0) {
3259		goto out;
3260	}
3261
3262	len1 = fs_path_len(path_before);
3263	len2 = fs_path_len(path_after);
3264	if (parent_ino_before != parent_ino_after || len1 != len2 ||
3265	     memcmp(path_before->start, path_after->start, len1)) {
3266		ret = 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3267		goto out;
3268	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3269	ret = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3270
3271	/*
3272	 * Ok, our new most direct ancestor has a higher inode number but
3273	 * wasn't moved/renamed. So maybe some of the new ancestors higher in
3274	 * the hierarchy have an higher inode number too *and* were renamed
3275	 * or moved - in this case we need to wait for the ancestor's rename
3276	 * or move operation before we can do the move/rename for the current
3277	 * inode.
3278	 */
3279	register_upper_dirs = 0;
3280	ino = parent_ino_after;
3281again:
3282	while ((ret == 0 || register_upper_dirs) && ino > sctx->cur_ino) {
3283		u64 parent_gen;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3284
3285		fs_path_reset(path_before);
3286		fs_path_reset(path_after);
3287
3288		ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3289				    &parent_gen, path_after);
3290		if (ret < 0)
3291			goto out;
3292		ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
3293				    NULL, path_before);
3294		if (ret == -ENOENT) {
 
 
3295			ret = 0;
3296			break;
3297		} else if (ret < 0) {
3298			goto out;
3299		}
3300
3301		len1 = fs_path_len(path_before);
3302		len2 = fs_path_len(path_after);
3303		if (parent_ino_before != parent_ino_after || len1 != len2 ||
3304		    memcmp(path_before->start, path_after->start, len1)) {
3305			ret = 1;
3306			if (register_upper_dirs) {
 
 
 
 
 
 
3307				break;
3308			} else {
3309				register_upper_dirs = 1;
3310				ino = parent_ref->dir;
3311				gen = parent_ref->dir_gen;
3312				goto again;
3313			}
3314		} else if (register_upper_dirs) {
3315			ret = add_pending_dir_move(sctx, ino, gen,
3316						   parent_ino_after);
3317			if (ret < 0 && ret != -EEXIST)
3318				goto out;
3319		}
3320
3321		ino = parent_ino_after;
3322		gen = parent_gen;
3323	}
3324
3325out:
3326	fs_path_free(path_before);
3327	fs_path_free(path_after);
3328
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3329	return ret;
3330}
3331
3332/*
3333 * This does all the move/link/unlink/rmdir magic.
3334 */
3335static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
3336{
 
3337	int ret = 0;
3338	struct recorded_ref *cur;
3339	struct recorded_ref *cur2;
3340	struct list_head check_dirs;
3341	struct fs_path *valid_path = NULL;
3342	u64 ow_inode = 0;
3343	u64 ow_gen;
 
3344	int did_overwrite = 0;
3345	int is_orphan = 0;
3346	u64 last_dir_ino_rm = 0;
 
 
 
3347
3348verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
3349
3350	/*
3351	 * This should never happen as the root dir always has the same ref
3352	 * which is always '..'
3353	 */
3354	BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
3355	INIT_LIST_HEAD(&check_dirs);
 
 
 
 
 
3356
3357	valid_path = fs_path_alloc();
3358	if (!valid_path) {
3359		ret = -ENOMEM;
3360		goto out;
3361	}
3362
3363	/*
3364	 * First, check if the first ref of the current inode was overwritten
3365	 * before. If yes, we know that the current inode was already orphanized
3366	 * and thus use the orphan name. If not, we can use get_cur_path to
3367	 * get the path of the first ref as it would like while receiving at
3368	 * this point in time.
3369	 * New inodes are always orphan at the beginning, so force to use the
3370	 * orphan name in this case.
3371	 * The first ref is stored in valid_path and will be updated if it
3372	 * gets moved around.
3373	 */
3374	if (!sctx->cur_inode_new) {
3375		ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
3376				sctx->cur_inode_gen);
3377		if (ret < 0)
3378			goto out;
3379		if (ret)
3380			did_overwrite = 1;
3381	}
3382	if (sctx->cur_inode_new || did_overwrite) {
3383		ret = gen_unique_name(sctx, sctx->cur_ino,
3384				sctx->cur_inode_gen, valid_path);
3385		if (ret < 0)
3386			goto out;
3387		is_orphan = 1;
3388	} else {
3389		ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3390				valid_path);
3391		if (ret < 0)
3392			goto out;
3393	}
3394
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3395	list_for_each_entry(cur, &sctx->new_refs, list) {
3396		/*
3397		 * We may have refs where the parent directory does not exist
3398		 * yet. This happens if the parent directories inum is higher
3399		 * the the current inum. To handle this case, we create the
3400		 * parent directory out of order. But we need to check if this
3401		 * did already happen before due to other refs in the same dir.
3402		 */
3403		ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3404		if (ret < 0)
3405			goto out;
3406		if (ret == inode_state_will_create) {
3407			ret = 0;
3408			/*
3409			 * First check if any of the current inodes refs did
3410			 * already create the dir.
3411			 */
3412			list_for_each_entry(cur2, &sctx->new_refs, list) {
3413				if (cur == cur2)
3414					break;
3415				if (cur2->dir == cur->dir) {
3416					ret = 1;
3417					break;
3418				}
3419			}
3420
3421			/*
3422			 * If that did not happen, check if a previous inode
3423			 * did already create the dir.
3424			 */
3425			if (!ret)
3426				ret = did_create_dir(sctx, cur->dir);
3427			if (ret < 0)
3428				goto out;
3429			if (!ret) {
3430				ret = send_create_inode(sctx, cur->dir);
3431				if (ret < 0)
3432					goto out;
 
3433			}
3434		}
3435
3436		/*
3437		 * Check if this new ref would overwrite the first ref of
3438		 * another unprocessed inode. If yes, orphanize the
3439		 * overwritten inode. If we find an overwritten ref that is
3440		 * not the first ref, simply unlink it.
3441		 */
3442		ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3443				cur->name, cur->name_len,
3444				&ow_inode, &ow_gen);
3445		if (ret < 0)
3446			goto out;
3447		if (ret) {
3448			ret = is_first_ref(sctx->parent_root,
3449					   ow_inode, cur->dir, cur->name,
3450					   cur->name_len);
3451			if (ret < 0)
3452				goto out;
3453			if (ret) {
3454				ret = orphanize_inode(sctx, ow_inode, ow_gen,
3455						cur->full_path);
3456				if (ret < 0)
3457					goto out;
3458			} else {
3459				ret = send_unlink(sctx, cur->full_path);
3460				if (ret < 0)
3461					goto out;
 
 
 
 
 
3462			}
3463		}
3464
3465		/*
3466		 * link/move the ref to the new place. If we have an orphan
3467		 * inode, move it and update valid_path. If not, link or move
3468		 * it depending on the inode mode.
3469		 */
3470		if (is_orphan) {
3471			ret = send_rename(sctx, valid_path, cur->full_path);
3472			if (ret < 0)
3473				goto out;
3474			is_orphan = 0;
3475			ret = fs_path_copy(valid_path, cur->full_path);
3476			if (ret < 0)
3477				goto out;
3478		} else {
3479			if (S_ISDIR(sctx->cur_inode_mode)) {
3480				/*
3481				 * Dirs can't be linked, so move it. For moved
3482				 * dirs, we always have one new and one deleted
3483				 * ref. The deleted ref is ignored later.
3484				 */
3485				ret = wait_for_parent_move(sctx, cur);
3486				if (ret < 0)
3487					goto out;
3488				if (ret) {
3489					ret = add_pending_dir_move(sctx,
3490							   sctx->cur_ino,
3491							   sctx->cur_inode_gen,
3492							   cur->dir);
3493					*pending_move = 1;
3494				} else {
3495					ret = send_rename(sctx, valid_path,
3496							  cur->full_path);
3497					if (!ret)
3498						ret = fs_path_copy(valid_path,
3499							       cur->full_path);
3500				}
3501				if (ret < 0)
3502					goto out;
3503			} else {
 
 
 
 
 
 
 
 
 
 
 
 
3504				ret = send_link(sctx, cur->full_path,
3505						valid_path);
3506				if (ret < 0)
3507					goto out;
3508			}
3509		}
3510		ret = dup_ref(cur, &check_dirs);
3511		if (ret < 0)
3512			goto out;
3513	}
3514
3515	if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
3516		/*
3517		 * Check if we can already rmdir the directory. If not,
3518		 * orphanize it. For every dir item inside that gets deleted
3519		 * later, we do this check again and rmdir it then if possible.
3520		 * See the use of check_dirs for more details.
3521		 */
3522		ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
3523				sctx->cur_ino);
3524		if (ret < 0)
3525			goto out;
3526		if (ret) {
3527			ret = send_rmdir(sctx, valid_path);
3528			if (ret < 0)
3529				goto out;
3530		} else if (!is_orphan) {
3531			ret = orphanize_inode(sctx, sctx->cur_ino,
3532					sctx->cur_inode_gen, valid_path);
3533			if (ret < 0)
3534				goto out;
3535			is_orphan = 1;
3536		}
3537
3538		list_for_each_entry(cur, &sctx->deleted_refs, list) {
3539			ret = dup_ref(cur, &check_dirs);
3540			if (ret < 0)
3541				goto out;
3542		}
3543	} else if (S_ISDIR(sctx->cur_inode_mode) &&
3544		   !list_empty(&sctx->deleted_refs)) {
3545		/*
3546		 * We have a moved dir. Add the old parent to check_dirs
3547		 */
3548		cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
3549				list);
3550		ret = dup_ref(cur, &check_dirs);
3551		if (ret < 0)
3552			goto out;
3553	} else if (!S_ISDIR(sctx->cur_inode_mode)) {
3554		/*
3555		 * We have a non dir inode. Go through all deleted refs and
3556		 * unlink them if they were not already overwritten by other
3557		 * inodes.
3558		 */
3559		list_for_each_entry(cur, &sctx->deleted_refs, list) {
3560			ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
3561					sctx->cur_ino, sctx->cur_inode_gen,
3562					cur->name, cur->name_len);
3563			if (ret < 0)
3564				goto out;
3565			if (!ret) {
 
 
 
 
 
 
 
 
 
 
 
 
3566				ret = send_unlink(sctx, cur->full_path);
3567				if (ret < 0)
3568					goto out;
3569			}
3570			ret = dup_ref(cur, &check_dirs);
3571			if (ret < 0)
3572				goto out;
3573		}
3574		/*
3575		 * If the inode is still orphan, unlink the orphan. This may
3576		 * happen when a previous inode did overwrite the first ref
3577		 * of this inode and no new refs were added for the current
3578		 * inode. Unlinking does not mean that the inode is deleted in
3579		 * all cases. There may still be links to this inode in other
3580		 * places.
3581		 */
3582		if (is_orphan) {
3583			ret = send_unlink(sctx, valid_path);
3584			if (ret < 0)
3585				goto out;
3586		}
3587	}
3588
3589	/*
3590	 * We did collect all parent dirs where cur_inode was once located. We
3591	 * now go through all these dirs and check if they are pending for
3592	 * deletion and if it's finally possible to perform the rmdir now.
3593	 * We also update the inode stats of the parent dirs here.
3594	 */
3595	list_for_each_entry(cur, &check_dirs, list) {
3596		/*
3597		 * In case we had refs into dirs that were not processed yet,
3598		 * we don't need to do the utime and rmdir logic for these dirs.
3599		 * The dir will be processed later.
3600		 */
3601		if (cur->dir > sctx->cur_ino)
3602			continue;
3603
3604		ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3605		if (ret < 0)
3606			goto out;
3607
3608		if (ret == inode_state_did_create ||
3609		    ret == inode_state_no_change) {
3610			/* TODO delayed utimes */
3611			ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3612			if (ret < 0)
3613				goto out;
3614		} else if (ret == inode_state_did_delete &&
3615			   cur->dir != last_dir_ino_rm) {
3616			ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
3617					sctx->cur_ino);
3618			if (ret < 0)
3619				goto out;
3620			if (ret) {
3621				ret = get_cur_path(sctx, cur->dir,
3622						   cur->dir_gen, valid_path);
3623				if (ret < 0)
3624					goto out;
3625				ret = send_rmdir(sctx, valid_path);
3626				if (ret < 0)
3627					goto out;
3628				last_dir_ino_rm = cur->dir;
3629			}
3630		}
3631	}
3632
3633	ret = 0;
3634
3635out:
3636	__free_recorded_refs(&check_dirs);
3637	free_recorded_refs(sctx);
3638	fs_path_free(valid_path);
3639	return ret;
3640}
3641
3642static int record_ref(struct btrfs_root *root, int num, u64 dir, int index,
3643		      struct fs_path *name, void *ctx, struct list_head *refs)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3644{
3645	int ret = 0;
3646	struct send_ctx *sctx = ctx;
3647	struct fs_path *p;
3648	u64 gen;
3649
3650	p = fs_path_alloc();
3651	if (!p)
3652		return -ENOMEM;
 
 
3653
3654	ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
3655			NULL, NULL);
3656	if (ret < 0)
3657		goto out;
 
3658
3659	ret = get_cur_path(sctx, dir, gen, p);
3660	if (ret < 0)
3661		goto out;
3662	ret = fs_path_add_path(p, name);
3663	if (ret < 0)
3664		goto out;
3665
3666	ret = __record_ref(refs, dir, gen, p);
3667
 
 
 
 
3668out:
3669	if (ret)
3670		fs_path_free(p);
 
 
 
3671	return ret;
3672}
3673
3674static int __record_new_ref(int num, u64 dir, int index,
3675			    struct fs_path *name,
3676			    void *ctx)
3677{
3678	struct send_ctx *sctx = ctx;
3679	return record_ref(sctx->send_root, num, dir, index, name,
3680			  ctx, &sctx->new_refs);
3681}
3682
3683
3684static int __record_deleted_ref(int num, u64 dir, int index,
3685				struct fs_path *name,
3686				void *ctx)
3687{
 
3688	struct send_ctx *sctx = ctx;
3689	return record_ref(sctx->parent_root, num, dir, index, name,
3690			  ctx, &sctx->deleted_refs);
3691}
3692
3693static int record_new_ref(struct send_ctx *sctx)
3694{
3695	int ret;
3696
3697	ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3698				sctx->cmp_key, 0, __record_new_ref, sctx);
3699	if (ret < 0)
3700		goto out;
3701	ret = 0;
3702
 
 
 
 
 
 
 
 
 
 
 
 
3703out:
3704	return ret;
3705}
3706
3707static int record_deleted_ref(struct send_ctx *sctx)
3708{
3709	int ret;
 
 
 
 
 
3710
3711	ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3712				sctx->cmp_key, 0, __record_deleted_ref, sctx);
3713	if (ret < 0)
3714		goto out;
3715	ret = 0;
3716
 
 
 
 
 
 
 
 
 
 
 
 
3717out:
3718	return ret;
3719}
3720
3721struct find_ref_ctx {
3722	u64 dir;
3723	u64 dir_gen;
3724	struct btrfs_root *root;
3725	struct fs_path *name;
3726	int found_idx;
3727};
3728
3729static int __find_iref(int num, u64 dir, int index,
3730		       struct fs_path *name,
3731		       void *ctx_)
3732{
3733	struct find_ref_ctx *ctx = ctx_;
3734	u64 dir_gen;
3735	int ret;
3736
3737	if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
3738	    strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
3739		/*
3740		 * To avoid doing extra lookups we'll only do this if everything
3741		 * else matches.
3742		 */
3743		ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
3744				     NULL, NULL, NULL);
3745		if (ret)
3746			return ret;
3747		if (dir_gen != ctx->dir_gen)
3748			return 0;
3749		ctx->found_idx = num;
3750		return 1;
3751	}
3752	return 0;
3753}
3754
3755static int find_iref(struct btrfs_root *root,
3756		     struct btrfs_path *path,
3757		     struct btrfs_key *key,
3758		     u64 dir, u64 dir_gen, struct fs_path *name)
3759{
3760	int ret;
3761	struct find_ref_ctx ctx;
3762
3763	ctx.dir = dir;
3764	ctx.name = name;
3765	ctx.dir_gen = dir_gen;
3766	ctx.found_idx = -1;
3767	ctx.root = root;
3768
3769	ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
 
3770	if (ret < 0)
3771		return ret;
3772
3773	if (ctx.found_idx == -1)
3774		return -ENOENT;
3775
3776	return ctx.found_idx;
3777}
3778
3779static int __record_changed_new_ref(int num, u64 dir, int index,
3780				    struct fs_path *name,
3781				    void *ctx)
3782{
3783	u64 dir_gen;
3784	int ret;
3785	struct send_ctx *sctx = ctx;
3786
3787	ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
3788			     NULL, NULL, NULL);
3789	if (ret)
3790		return ret;
3791
3792	ret = find_iref(sctx->parent_root, sctx->right_path,
3793			sctx->cmp_key, dir, dir_gen, name);
3794	if (ret == -ENOENT)
3795		ret = __record_new_ref(num, dir, index, name, sctx);
3796	else if (ret > 0)
3797		ret = 0;
3798
 
3799	return ret;
3800}
3801
3802static int __record_changed_deleted_ref(int num, u64 dir, int index,
3803					struct fs_path *name,
3804					void *ctx)
3805{
3806	u64 dir_gen;
3807	int ret;
3808	struct send_ctx *sctx = ctx;
3809
3810	ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
3811			     NULL, NULL, NULL);
3812	if (ret)
3813		return ret;
3814
3815	ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
3816			dir, dir_gen, name);
3817	if (ret == -ENOENT)
3818		ret = __record_deleted_ref(num, dir, index, name, sctx);
3819	else if (ret > 0)
3820		ret = 0;
3821
 
3822	return ret;
3823}
3824
3825static int record_changed_ref(struct send_ctx *sctx)
3826{
3827	int ret = 0;
3828
3829	ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3830			sctx->cmp_key, 0, __record_changed_new_ref, sctx);
3831	if (ret < 0)
3832		goto out;
3833	ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3834			sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
3835	if (ret < 0)
3836		goto out;
3837	ret = 0;
3838
3839out:
3840	return ret;
3841}
3842
3843/*
3844 * Record and process all refs at once. Needed when an inode changes the
3845 * generation number, which means that it was deleted and recreated.
3846 */
3847static int process_all_refs(struct send_ctx *sctx,
3848			    enum btrfs_compare_tree_result cmd)
3849{
3850	int ret;
 
3851	struct btrfs_root *root;
3852	struct btrfs_path *path;
3853	struct btrfs_key key;
3854	struct btrfs_key found_key;
3855	struct extent_buffer *eb;
3856	int slot;
3857	iterate_inode_ref_t cb;
3858	int pending_move = 0;
3859
3860	path = alloc_path_for_send();
3861	if (!path)
3862		return -ENOMEM;
3863
3864	if (cmd == BTRFS_COMPARE_TREE_NEW) {
3865		root = sctx->send_root;
3866		cb = __record_new_ref;
3867	} else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
3868		root = sctx->parent_root;
3869		cb = __record_deleted_ref;
3870	} else {
3871		btrfs_err(sctx->send_root->fs_info,
3872				"Wrong command %d in process_all_refs", cmd);
3873		ret = -EINVAL;
3874		goto out;
3875	}
3876
3877	key.objectid = sctx->cmp_key->objectid;
3878	key.type = BTRFS_INODE_REF_KEY;
3879	key.offset = 0;
3880	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3881	if (ret < 0)
3882		goto out;
3883
3884	while (1) {
3885		eb = path->nodes[0];
3886		slot = path->slots[0];
3887		if (slot >= btrfs_header_nritems(eb)) {
3888			ret = btrfs_next_leaf(root, path);
3889			if (ret < 0)
3890				goto out;
3891			else if (ret > 0)
3892				break;
3893			continue;
3894		}
3895
3896		btrfs_item_key_to_cpu(eb, &found_key, slot);
3897
3898		if (found_key.objectid != key.objectid ||
3899		    (found_key.type != BTRFS_INODE_REF_KEY &&
3900		     found_key.type != BTRFS_INODE_EXTREF_KEY))
3901			break;
3902
3903		ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
3904		if (ret < 0)
3905			goto out;
3906
3907		path->slots[0]++;
 
 
 
3908	}
3909	btrfs_release_path(path);
3910
 
 
 
 
 
3911	ret = process_recorded_refs(sctx, &pending_move);
3912	/* Only applicable to an incremental send. */
3913	ASSERT(pending_move == 0);
3914
3915out:
3916	btrfs_free_path(path);
3917	return ret;
3918}
3919
3920static int send_set_xattr(struct send_ctx *sctx,
3921			  struct fs_path *path,
3922			  const char *name, int name_len,
3923			  const char *data, int data_len)
3924{
3925	int ret = 0;
3926
3927	ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
3928	if (ret < 0)
3929		goto out;
3930
3931	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3932	TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3933	TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);
3934
3935	ret = send_cmd(sctx);
3936
3937tlv_put_failure:
3938out:
3939	return ret;
3940}
3941
3942static int send_remove_xattr(struct send_ctx *sctx,
3943			  struct fs_path *path,
3944			  const char *name, int name_len)
3945{
3946	int ret = 0;
3947
3948	ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
3949	if (ret < 0)
3950		goto out;
3951
3952	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
3953	TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
3954
3955	ret = send_cmd(sctx);
3956
3957tlv_put_failure:
3958out:
3959	return ret;
3960}
3961
3962static int __process_new_xattr(int num, struct btrfs_key *di_key,
3963			       const char *name, int name_len,
3964			       const char *data, int data_len,
3965			       u8 type, void *ctx)
3966{
3967	int ret;
3968	struct send_ctx *sctx = ctx;
3969	struct fs_path *p;
3970	posix_acl_xattr_header dummy_acl;
 
 
 
 
3971
3972	p = fs_path_alloc();
3973	if (!p)
3974		return -ENOMEM;
3975
3976	/*
3977	 * This hack is needed because empty acl's are stored as zero byte
3978	 * data in xattrs. Problem with that is, that receiving these zero byte
3979	 * acl's will fail later. To fix this, we send a dummy acl list that
3980	 * only contains the version number and no entries.
3981	 */
3982	if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
3983	    !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
3984		if (data_len == 0) {
3985			dummy_acl.a_version =
3986					cpu_to_le32(POSIX_ACL_XATTR_VERSION);
3987			data = (char *)&dummy_acl;
3988			data_len = sizeof(dummy_acl);
3989		}
3990	}
3991
3992	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
3993	if (ret < 0)
3994		goto out;
3995
3996	ret = send_set_xattr(sctx, p, name, name_len, data, data_len);
3997
3998out:
3999	fs_path_free(p);
4000	return ret;
4001}
4002
4003static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
4004				   const char *name, int name_len,
4005				   const char *data, int data_len,
4006				   u8 type, void *ctx)
4007{
4008	int ret;
4009	struct send_ctx *sctx = ctx;
4010	struct fs_path *p;
4011
4012	p = fs_path_alloc();
4013	if (!p)
4014		return -ENOMEM;
4015
4016	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4017	if (ret < 0)
4018		goto out;
4019
4020	ret = send_remove_xattr(sctx, p, name, name_len);
4021
4022out:
4023	fs_path_free(p);
4024	return ret;
4025}
4026
4027static int process_new_xattr(struct send_ctx *sctx)
4028{
4029	int ret = 0;
4030
4031	ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4032			       sctx->cmp_key, __process_new_xattr, sctx);
4033
4034	return ret;
4035}
4036
4037static int process_deleted_xattr(struct send_ctx *sctx)
4038{
4039	int ret;
4040
4041	ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4042			       sctx->cmp_key, __process_deleted_xattr, sctx);
4043
4044	return ret;
4045}
4046
4047struct find_xattr_ctx {
4048	const char *name;
4049	int name_len;
4050	int found_idx;
4051	char *found_data;
4052	int found_data_len;
4053};
4054
4055static int __find_xattr(int num, struct btrfs_key *di_key,
4056			const char *name, int name_len,
4057			const char *data, int data_len,
4058			u8 type, void *vctx)
4059{
4060	struct find_xattr_ctx *ctx = vctx;
4061
4062	if (name_len == ctx->name_len &&
4063	    strncmp(name, ctx->name, name_len) == 0) {
4064		ctx->found_idx = num;
4065		ctx->found_data_len = data_len;
4066		ctx->found_data = kmemdup(data, data_len, GFP_NOFS);
4067		if (!ctx->found_data)
4068			return -ENOMEM;
4069		return 1;
4070	}
4071	return 0;
4072}
4073
4074static int find_xattr(struct btrfs_root *root,
4075		      struct btrfs_path *path,
4076		      struct btrfs_key *key,
4077		      const char *name, int name_len,
4078		      char **data, int *data_len)
4079{
4080	int ret;
4081	struct find_xattr_ctx ctx;
4082
4083	ctx.name = name;
4084	ctx.name_len = name_len;
4085	ctx.found_idx = -1;
4086	ctx.found_data = NULL;
4087	ctx.found_data_len = 0;
4088
4089	ret = iterate_dir_item(root, path, key, __find_xattr, &ctx);
4090	if (ret < 0)
4091		return ret;
4092
4093	if (ctx.found_idx == -1)
4094		return -ENOENT;
4095	if (data) {
4096		*data = ctx.found_data;
4097		*data_len = ctx.found_data_len;
4098	} else {
4099		kfree(ctx.found_data);
4100	}
4101	return ctx.found_idx;
4102}
4103
4104
4105static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
4106				       const char *name, int name_len,
4107				       const char *data, int data_len,
4108				       u8 type, void *ctx)
4109{
4110	int ret;
4111	struct send_ctx *sctx = ctx;
4112	char *found_data = NULL;
4113	int found_data_len  = 0;
4114
4115	ret = find_xattr(sctx->parent_root, sctx->right_path,
4116			 sctx->cmp_key, name, name_len, &found_data,
4117			 &found_data_len);
4118	if (ret == -ENOENT) {
4119		ret = __process_new_xattr(num, di_key, name, name_len, data,
4120				data_len, type, ctx);
4121	} else if (ret >= 0) {
4122		if (data_len != found_data_len ||
4123		    memcmp(data, found_data, data_len)) {
4124			ret = __process_new_xattr(num, di_key, name, name_len,
4125					data, data_len, type, ctx);
4126		} else {
4127			ret = 0;
4128		}
4129	}
4130
4131	kfree(found_data);
4132	return ret;
4133}
4134
4135static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
4136					   const char *name, int name_len,
4137					   const char *data, int data_len,
4138					   u8 type, void *ctx)
4139{
4140	int ret;
4141	struct send_ctx *sctx = ctx;
4142
4143	ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
4144			 name, name_len, NULL, NULL);
4145	if (ret == -ENOENT)
4146		ret = __process_deleted_xattr(num, di_key, name, name_len, data,
4147				data_len, type, ctx);
4148	else if (ret >= 0)
4149		ret = 0;
4150
4151	return ret;
4152}
4153
4154static int process_changed_xattr(struct send_ctx *sctx)
4155{
4156	int ret = 0;
4157
4158	ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4159			sctx->cmp_key, __process_changed_new_xattr, sctx);
4160	if (ret < 0)
4161		goto out;
4162	ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4163			sctx->cmp_key, __process_changed_deleted_xattr, sctx);
4164
4165out:
4166	return ret;
4167}
4168
4169static int process_all_new_xattrs(struct send_ctx *sctx)
4170{
4171	int ret;
 
4172	struct btrfs_root *root;
4173	struct btrfs_path *path;
4174	struct btrfs_key key;
4175	struct btrfs_key found_key;
4176	struct extent_buffer *eb;
4177	int slot;
4178
4179	path = alloc_path_for_send();
4180	if (!path)
4181		return -ENOMEM;
4182
4183	root = sctx->send_root;
4184
4185	key.objectid = sctx->cmp_key->objectid;
4186	key.type = BTRFS_XATTR_ITEM_KEY;
4187	key.offset = 0;
4188	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4189	if (ret < 0)
4190		goto out;
4191
4192	while (1) {
4193		eb = path->nodes[0];
4194		slot = path->slots[0];
4195		if (slot >= btrfs_header_nritems(eb)) {
4196			ret = btrfs_next_leaf(root, path);
4197			if (ret < 0) {
4198				goto out;
4199			} else if (ret > 0) {
4200				ret = 0;
4201				break;
4202			}
4203			continue;
4204		}
4205
4206		btrfs_item_key_to_cpu(eb, &found_key, slot);
4207		if (found_key.objectid != key.objectid ||
4208		    found_key.type != key.type) {
4209			ret = 0;
4210			goto out;
4211		}
4212
4213		ret = iterate_dir_item(root, path, &found_key,
4214				       __process_new_xattr, sctx);
4215		if (ret < 0)
4216			goto out;
4217
4218		path->slots[0]++;
4219	}
 
 
 
4220
4221out:
4222	btrfs_free_path(path);
4223	return ret;
4224}
4225
4226static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
 
4227{
4228	struct btrfs_root *root = sctx->send_root;
4229	struct btrfs_fs_info *fs_info = root->fs_info;
4230	struct inode *inode;
4231	struct page *page;
4232	char *addr;
4233	struct btrfs_key key;
4234	pgoff_t index = offset >> PAGE_CACHE_SHIFT;
4235	pgoff_t last_index;
4236	unsigned pg_offset = offset & ~PAGE_CACHE_MASK;
4237	ssize_t ret = 0;
4238
4239	key.objectid = sctx->cur_ino;
4240	key.type = BTRFS_INODE_ITEM_KEY;
4241	key.offset = 0;
 
 
 
 
 
 
 
 
 
 
4242
4243	inode = btrfs_iget(fs_info->sb, &key, root, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
4244	if (IS_ERR(inode))
4245		return PTR_ERR(inode);
4246
4247	if (offset + len > i_size_read(inode)) {
4248		if (offset > i_size_read(inode))
4249			len = 0;
4250		else
4251			len = offset - i_size_read(inode);
 
 
 
 
 
 
 
 
 
 
4252	}
4253	if (len == 0)
4254		goto out;
4255
4256	last_index = (offset + len - 1) >> PAGE_CACHE_SHIFT;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4257
4258	/* initial readahead */
4259	memset(&sctx->ra, 0, sizeof(struct file_ra_state));
4260	file_ra_state_init(&sctx->ra, inode->i_mapping);
4261	btrfs_force_ra(inode->i_mapping, &sctx->ra, NULL, index,
4262		       last_index - index + 1);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4263
4264	while (index <= last_index) {
4265		unsigned cur_len = min_t(unsigned, len,
4266					 PAGE_CACHE_SIZE - pg_offset);
4267		page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
4268		if (!page) {
4269			ret = -ENOMEM;
4270			break;
 
 
 
 
 
 
 
 
 
4271		}
4272
4273		if (!PageUptodate(page)) {
4274			btrfs_readpage(NULL, page);
4275			lock_page(page);
4276			if (!PageUptodate(page)) {
4277				unlock_page(page);
4278				page_cache_release(page);
 
 
 
 
 
 
 
 
 
 
4279				ret = -EIO;
4280				break;
4281			}
 
 
 
 
 
4282		}
4283
4284		addr = kmap(page);
4285		memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len);
4286		kunmap(page);
4287		unlock_page(page);
4288		page_cache_release(page);
4289		index++;
4290		pg_offset = 0;
4291		len -= cur_len;
4292		ret += cur_len;
4293	}
4294out:
4295	iput(inode);
4296	return ret;
4297}
4298
4299/*
4300 * Read some bytes from the current inode/file and send a write command to
4301 * user space.
4302 */
4303static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
4304{
 
4305	int ret = 0;
4306	struct fs_path *p;
4307	ssize_t num_read = 0;
4308
4309	p = fs_path_alloc();
4310	if (!p)
4311		return -ENOMEM;
4312
4313verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len);
4314
4315	num_read = fill_read_buf(sctx, offset, len);
4316	if (num_read <= 0) {
4317		if (num_read < 0)
4318			ret = num_read;
4319		goto out;
4320	}
4321
4322	ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4323	if (ret < 0)
4324		goto out;
4325
4326	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4327	if (ret < 0)
4328		goto out;
4329
4330	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4331	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4332	TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
 
 
4333
4334	ret = send_cmd(sctx);
4335
4336tlv_put_failure:
4337out:
4338	fs_path_free(p);
4339	if (ret < 0)
4340		return ret;
4341	return num_read;
4342}
4343
4344/*
4345 * Send a clone command to user space.
4346 */
4347static int send_clone(struct send_ctx *sctx,
4348		      u64 offset, u32 len,
4349		      struct clone_root *clone_root)
4350{
4351	int ret = 0;
4352	struct fs_path *p;
4353	u64 gen;
4354
4355verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, "
4356	       "clone_inode=%llu, clone_offset=%llu\n", offset, len,
4357		clone_root->root->objectid, clone_root->ino,
4358		clone_root->offset);
4359
4360	p = fs_path_alloc();
4361	if (!p)
4362		return -ENOMEM;
4363
4364	ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
4365	if (ret < 0)
4366		goto out;
4367
4368	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4369	if (ret < 0)
4370		goto out;
4371
4372	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4373	TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
4374	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4375
4376	if (clone_root->root == sctx->send_root) {
4377		ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
4378				&gen, NULL, NULL, NULL, NULL);
4379		if (ret < 0)
4380			goto out;
4381		ret = get_cur_path(sctx, clone_root->ino, gen, p);
4382	} else {
4383		ret = get_inode_path(clone_root->root, clone_root->ino, p);
4384	}
4385	if (ret < 0)
4386		goto out;
4387
4388	TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4389			clone_root->root->root_item.uuid);
 
 
 
 
 
 
 
 
 
 
 
 
 
4390	TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
4391		    le64_to_cpu(clone_root->root->root_item.ctransid));
4392	TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
4393	TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
4394			clone_root->offset);
4395
4396	ret = send_cmd(sctx);
4397
4398tlv_put_failure:
4399out:
4400	fs_path_free(p);
4401	return ret;
4402}
4403
4404/*
4405 * Send an update extent command to user space.
4406 */
4407static int send_update_extent(struct send_ctx *sctx,
4408			      u64 offset, u32 len)
4409{
4410	int ret = 0;
4411	struct fs_path *p;
4412
4413	p = fs_path_alloc();
4414	if (!p)
4415		return -ENOMEM;
4416
4417	ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
4418	if (ret < 0)
4419		goto out;
4420
4421	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4422	if (ret < 0)
4423		goto out;
4424
4425	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4426	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4427	TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);
4428
4429	ret = send_cmd(sctx);
4430
4431tlv_put_failure:
4432out:
4433	fs_path_free(p);
4434	return ret;
4435}
4436
4437static int send_hole(struct send_ctx *sctx, u64 end)
4438{
4439	struct fs_path *p = NULL;
 
4440	u64 offset = sctx->cur_inode_last_extent;
4441	u64 len;
4442	int ret = 0;
4443
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4444	p = fs_path_alloc();
4445	if (!p)
4446		return -ENOMEM;
4447	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
4448	if (ret < 0)
4449		goto tlv_put_failure;
4450	memset(sctx->read_buf, 0, BTRFS_SEND_READ_SIZE);
4451	while (offset < end) {
4452		len = min_t(u64, end - offset, BTRFS_SEND_READ_SIZE);
4453
4454		ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
4455		if (ret < 0)
4456			break;
4457		TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
4458		TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4459		TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len);
 
 
 
 
4460		ret = send_cmd(sctx);
4461		if (ret < 0)
4462			break;
4463		offset += len;
4464	}
 
4465tlv_put_failure:
4466	fs_path_free(p);
4467	return ret;
4468}
4469
4470static int send_write_or_clone(struct send_ctx *sctx,
4471			       struct btrfs_path *path,
4472			       struct btrfs_key *key,
4473			       struct clone_root *clone_root)
4474{
4475	int ret = 0;
 
 
 
 
 
4476	struct btrfs_file_extent_item *ei;
4477	u64 offset = key->offset;
4478	u64 pos = 0;
4479	u64 len;
4480	u32 l;
4481	u8 type;
4482	u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4483
4484	ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4485			struct btrfs_file_extent_item);
4486	type = btrfs_file_extent_type(path->nodes[0], ei);
4487	if (type == BTRFS_FILE_EXTENT_INLINE) {
4488		len = btrfs_file_extent_inline_len(path->nodes[0],
4489						   path->slots[0], ei);
4490		/*
4491		 * it is possible the inline item won't cover the whole page,
4492		 * but there may be items after this page.  Make
4493		 * sure to send the whole thing
 
 
4494		 */
4495		len = PAGE_CACHE_ALIGN(len);
4496	} else {
4497		len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
 
 
 
 
 
 
4498	}
4499
4500	if (offset + len > sctx->cur_inode_size)
4501		len = sctx->cur_inode_size - offset;
4502	if (len == 0) {
4503		ret = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4504		goto out;
4505	}
4506
4507	if (clone_root && IS_ALIGNED(offset + len, bs)) {
4508		ret = send_clone(sctx, offset, len, clone_root);
4509	} else if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) {
4510		ret = send_update_extent(sctx, offset, len);
4511	} else {
4512		while (pos < len) {
4513			l = len - pos;
4514			if (l > BTRFS_SEND_READ_SIZE)
4515				l = BTRFS_SEND_READ_SIZE;
4516			ret = send_write(sctx, pos + offset, l);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4517			if (ret < 0)
4518				goto out;
4519			if (!ret)
4520				break;
4521			pos += ret;
4522		}
4523		ret = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4524	}
 
 
 
 
 
4525out:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4526	return ret;
4527}
4528
4529static int is_extent_unchanged(struct send_ctx *sctx,
4530			       struct btrfs_path *left_path,
4531			       struct btrfs_key *ekey)
4532{
4533	int ret = 0;
4534	struct btrfs_key key;
4535	struct btrfs_path *path = NULL;
4536	struct extent_buffer *eb;
4537	int slot;
4538	struct btrfs_key found_key;
4539	struct btrfs_file_extent_item *ei;
4540	u64 left_disknr;
4541	u64 right_disknr;
4542	u64 left_offset;
4543	u64 right_offset;
4544	u64 left_offset_fixed;
4545	u64 left_len;
4546	u64 right_len;
4547	u64 left_gen;
4548	u64 right_gen;
4549	u8 left_type;
4550	u8 right_type;
4551
4552	path = alloc_path_for_send();
4553	if (!path)
4554		return -ENOMEM;
4555
4556	eb = left_path->nodes[0];
4557	slot = left_path->slots[0];
4558	ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
4559	left_type = btrfs_file_extent_type(eb, ei);
4560
4561	if (left_type != BTRFS_FILE_EXTENT_REG) {
4562		ret = 0;
4563		goto out;
4564	}
4565	left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
4566	left_len = btrfs_file_extent_num_bytes(eb, ei);
4567	left_offset = btrfs_file_extent_offset(eb, ei);
4568	left_gen = btrfs_file_extent_generation(eb, ei);
4569
4570	/*
4571	 * Following comments will refer to these graphics. L is the left
4572	 * extents which we are checking at the moment. 1-8 are the right
4573	 * extents that we iterate.
4574	 *
4575	 *       |-----L-----|
4576	 * |-1-|-2a-|-3-|-4-|-5-|-6-|
4577	 *
4578	 *       |-----L-----|
4579	 * |--1--|-2b-|...(same as above)
4580	 *
4581	 * Alternative situation. Happens on files where extents got split.
4582	 *       |-----L-----|
4583	 * |-----------7-----------|-6-|
4584	 *
4585	 * Alternative situation. Happens on files which got larger.
4586	 *       |-----L-----|
4587	 * |-8-|
4588	 * Nothing follows after 8.
4589	 */
4590
4591	key.objectid = ekey->objectid;
4592	key.type = BTRFS_EXTENT_DATA_KEY;
4593	key.offset = ekey->offset;
4594	ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
4595	if (ret < 0)
4596		goto out;
4597	if (ret) {
4598		ret = 0;
4599		goto out;
4600	}
4601
4602	/*
4603	 * Handle special case where the right side has no extents at all.
4604	 */
4605	eb = path->nodes[0];
4606	slot = path->slots[0];
4607	btrfs_item_key_to_cpu(eb, &found_key, slot);
4608	if (found_key.objectid != key.objectid ||
4609	    found_key.type != key.type) {
4610		/* If we're a hole then just pretend nothing changed */
4611		ret = (left_disknr) ? 0 : 1;
4612		goto out;
4613	}
4614
4615	/*
4616	 * We're now on 2a, 2b or 7.
4617	 */
4618	key = found_key;
4619	while (key.offset < ekey->offset + left_len) {
4620		ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
4621		right_type = btrfs_file_extent_type(eb, ei);
4622		if (right_type != BTRFS_FILE_EXTENT_REG) {
 
4623			ret = 0;
4624			goto out;
4625		}
4626
4627		right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
4628		right_len = btrfs_file_extent_num_bytes(eb, ei);
4629		right_offset = btrfs_file_extent_offset(eb, ei);
4630		right_gen = btrfs_file_extent_generation(eb, ei);
 
 
4631
4632		/*
4633		 * Are we at extent 8? If yes, we know the extent is changed.
4634		 * This may only happen on the first iteration.
4635		 */
4636		if (found_key.offset + right_len <= ekey->offset) {
4637			/* If we're a hole just pretend nothing changed */
4638			ret = (left_disknr) ? 0 : 1;
4639			goto out;
4640		}
4641
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4642		left_offset_fixed = left_offset;
4643		if (key.offset < ekey->offset) {
4644			/* Fix the right offset for 2a and 7. */
4645			right_offset += ekey->offset - key.offset;
4646		} else {
4647			/* Fix the left offset for all behind 2a and 2b */
4648			left_offset_fixed += key.offset - ekey->offset;
4649		}
4650
4651		/*
4652		 * Check if we have the same extent.
4653		 */
4654		if (left_disknr != right_disknr ||
4655		    left_offset_fixed != right_offset ||
4656		    left_gen != right_gen) {
4657			ret = 0;
4658			goto out;
4659		}
4660
4661		/*
4662		 * Go to the next extent.
4663		 */
4664		ret = btrfs_next_item(sctx->parent_root, path);
4665		if (ret < 0)
4666			goto out;
4667		if (!ret) {
4668			eb = path->nodes[0];
4669			slot = path->slots[0];
4670			btrfs_item_key_to_cpu(eb, &found_key, slot);
4671		}
4672		if (ret || found_key.objectid != key.objectid ||
4673		    found_key.type != key.type) {
4674			key.offset += right_len;
4675			break;
4676		}
4677		if (found_key.offset != key.offset + right_len) {
4678			ret = 0;
4679			goto out;
4680		}
4681		key = found_key;
4682	}
4683
4684	/*
4685	 * We're now behind the left extent (treat as unchanged) or at the end
4686	 * of the right side (treat as changed).
4687	 */
4688	if (key.offset >= ekey->offset + left_len)
4689		ret = 1;
4690	else
4691		ret = 0;
4692
4693
4694out:
4695	btrfs_free_path(path);
4696	return ret;
4697}
4698
4699static int get_last_extent(struct send_ctx *sctx, u64 offset)
4700{
4701	struct btrfs_path *path;
4702	struct btrfs_root *root = sctx->send_root;
4703	struct btrfs_file_extent_item *fi;
4704	struct btrfs_key key;
4705	u64 extent_end;
4706	u8 type;
4707	int ret;
4708
4709	path = alloc_path_for_send();
4710	if (!path)
4711		return -ENOMEM;
4712
4713	sctx->cur_inode_last_extent = 0;
4714
4715	key.objectid = sctx->cur_ino;
4716	key.type = BTRFS_EXTENT_DATA_KEY;
4717	key.offset = offset;
4718	ret = btrfs_search_slot_for_read(root, &key, path, 0, 1);
4719	if (ret < 0)
4720		goto out;
4721	ret = 0;
4722	btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
4723	if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY)
4724		goto out;
4725
4726	fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
4727			    struct btrfs_file_extent_item);
4728	type = btrfs_file_extent_type(path->nodes[0], fi);
4729	if (type == BTRFS_FILE_EXTENT_INLINE) {
4730		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
4731							path->slots[0], fi);
4732		extent_end = ALIGN(key.offset + size,
4733				   sctx->send_root->sectorsize);
4734	} else {
4735		extent_end = key.offset +
4736			btrfs_file_extent_num_bytes(path->nodes[0], fi);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4737	}
4738	sctx->cur_inode_last_extent = extent_end;
4739out:
4740	btrfs_free_path(path);
4741	return ret;
4742}
4743
4744static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
4745			   struct btrfs_key *key)
4746{
4747	struct btrfs_file_extent_item *fi;
4748	u64 extent_end;
4749	u8 type;
4750	int ret = 0;
4751
4752	if (sctx->cur_ino != key->objectid || !need_send_hole(sctx))
4753		return 0;
4754
4755	if (sctx->cur_inode_last_extent == (u64)-1) {
 
 
 
 
 
 
 
 
 
 
 
4756		ret = get_last_extent(sctx, key->offset - 1);
4757		if (ret)
4758			return ret;
4759	}
4760
4761	fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
4762			    struct btrfs_file_extent_item);
4763	type = btrfs_file_extent_type(path->nodes[0], fi);
4764	if (type == BTRFS_FILE_EXTENT_INLINE) {
4765		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
4766							path->slots[0], fi);
4767		extent_end = ALIGN(key->offset + size,
4768				   sctx->send_root->sectorsize);
4769	} else {
4770		extent_end = key->offset +
4771			btrfs_file_extent_num_bytes(path->nodes[0], fi);
4772	}
4773
4774	if (path->slots[0] == 0 &&
4775	    sctx->cur_inode_last_extent < key->offset) {
4776		/*
4777		 * We might have skipped entire leafs that contained only
4778		 * file extent items for our current inode. These leafs have
4779		 * a generation number smaller (older) than the one in the
4780		 * current leaf and the leaf our last extent came from, and
4781		 * are located between these 2 leafs.
4782		 */
4783		ret = get_last_extent(sctx, key->offset - 1);
4784		if (ret)
4785			return ret;
 
 
 
 
4786	}
4787
4788	if (sctx->cur_inode_last_extent < key->offset)
4789		ret = send_hole(sctx, key->offset);
4790	sctx->cur_inode_last_extent = extent_end;
4791	return ret;
4792}
4793
4794static int process_extent(struct send_ctx *sctx,
4795			  struct btrfs_path *path,
4796			  struct btrfs_key *key)
4797{
4798	struct clone_root *found_clone = NULL;
4799	int ret = 0;
4800
4801	if (S_ISLNK(sctx->cur_inode_mode))
4802		return 0;
4803
4804	if (sctx->parent_root && !sctx->cur_inode_new) {
4805		ret = is_extent_unchanged(sctx, path, key);
4806		if (ret < 0)
4807			goto out;
4808		if (ret) {
4809			ret = 0;
4810			goto out_hole;
4811		}
4812	} else {
4813		struct btrfs_file_extent_item *ei;
4814		u8 type;
4815
4816		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4817				    struct btrfs_file_extent_item);
4818		type = btrfs_file_extent_type(path->nodes[0], ei);
4819		if (type == BTRFS_FILE_EXTENT_PREALLOC ||
4820		    type == BTRFS_FILE_EXTENT_REG) {
4821			/*
4822			 * The send spec does not have a prealloc command yet,
4823			 * so just leave a hole for prealloc'ed extents until
4824			 * we have enough commands queued up to justify rev'ing
4825			 * the send spec.
4826			 */
4827			if (type == BTRFS_FILE_EXTENT_PREALLOC) {
4828				ret = 0;
4829				goto out;
4830			}
4831
4832			/* Have a hole, just skip it. */
4833			if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
4834				ret = 0;
4835				goto out;
4836			}
4837		}
4838	}
4839
4840	ret = find_extent_clone(sctx, path, key->objectid, key->offset,
4841			sctx->cur_inode_size, &found_clone);
4842	if (ret != -ENOENT && ret < 0)
4843		goto out;
4844
4845	ret = send_write_or_clone(sctx, path, key, found_clone);
4846	if (ret)
4847		goto out;
4848out_hole:
4849	ret = maybe_send_hole(sctx, path, key);
4850out:
4851	return ret;
4852}
4853
4854static int process_all_extents(struct send_ctx *sctx)
4855{
4856	int ret;
 
4857	struct btrfs_root *root;
4858	struct btrfs_path *path;
4859	struct btrfs_key key;
4860	struct btrfs_key found_key;
4861	struct extent_buffer *eb;
4862	int slot;
4863
4864	root = sctx->send_root;
4865	path = alloc_path_for_send();
4866	if (!path)
4867		return -ENOMEM;
4868
4869	key.objectid = sctx->cmp_key->objectid;
4870	key.type = BTRFS_EXTENT_DATA_KEY;
4871	key.offset = 0;
4872	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4873	if (ret < 0)
4874		goto out;
4875
4876	while (1) {
4877		eb = path->nodes[0];
4878		slot = path->slots[0];
4879
4880		if (slot >= btrfs_header_nritems(eb)) {
4881			ret = btrfs_next_leaf(root, path);
4882			if (ret < 0) {
4883				goto out;
4884			} else if (ret > 0) {
4885				ret = 0;
4886				break;
4887			}
4888			continue;
4889		}
4890
4891		btrfs_item_key_to_cpu(eb, &found_key, slot);
4892
4893		if (found_key.objectid != key.objectid ||
4894		    found_key.type != key.type) {
4895			ret = 0;
4896			goto out;
4897		}
4898
4899		ret = process_extent(sctx, path, &found_key);
4900		if (ret < 0)
4901			goto out;
4902
4903		path->slots[0]++;
4904	}
 
 
 
4905
4906out:
4907	btrfs_free_path(path);
4908	return ret;
4909}
4910
4911static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
4912					   int *pending_move,
4913					   int *refs_processed)
4914{
4915	int ret = 0;
4916
4917	if (sctx->cur_ino == 0)
4918		goto out;
4919	if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
4920	    sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
4921		goto out;
4922	if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
4923		goto out;
4924
4925	ret = process_recorded_refs(sctx, pending_move);
4926	if (ret < 0)
4927		goto out;
4928
4929	*refs_processed = 1;
4930out:
4931	return ret;
4932}
4933
4934static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
4935{
4936	int ret = 0;
 
4937	u64 left_mode;
4938	u64 left_uid;
4939	u64 left_gid;
 
4940	u64 right_mode;
4941	u64 right_uid;
4942	u64 right_gid;
 
4943	int need_chmod = 0;
4944	int need_chown = 0;
 
 
4945	int pending_move = 0;
4946	int refs_processed = 0;
4947
 
 
 
4948	ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
4949					      &refs_processed);
4950	if (ret < 0)
4951		goto out;
4952
4953	/*
4954	 * We have processed the refs and thus need to advance send_progress.
4955	 * Now, calls to get_cur_xxx will take the updated refs of the current
4956	 * inode into account.
4957	 *
4958	 * On the other hand, if our current inode is a directory and couldn't
4959	 * be moved/renamed because its parent was renamed/moved too and it has
4960	 * a higher inode number, we can only move/rename our current inode
4961	 * after we moved/renamed its parent. Therefore in this case operate on
4962	 * the old path (pre move/rename) of our current inode, and the
4963	 * move/rename will be performed later.
4964	 */
4965	if (refs_processed && !pending_move)
4966		sctx->send_progress = sctx->cur_ino + 1;
4967
4968	if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
4969		goto out;
4970	if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
4971		goto out;
4972
4973	ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
4974			&left_mode, &left_uid, &left_gid, NULL);
4975	if (ret < 0)
4976		goto out;
 
 
 
 
4977
4978	if (!sctx->parent_root || sctx->cur_inode_new) {
4979		need_chown = 1;
4980		if (!S_ISLNK(sctx->cur_inode_mode))
4981			need_chmod = 1;
 
 
4982	} else {
4983		ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
4984				NULL, NULL, &right_mode, &right_uid,
4985				&right_gid, NULL);
4986		if (ret < 0)
4987			goto out;
 
 
 
 
 
4988
4989		if (left_uid != right_uid || left_gid != right_gid)
4990			need_chown = 1;
4991		if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
4992			need_chmod = 1;
 
 
 
 
 
 
4993	}
4994
4995	if (S_ISREG(sctx->cur_inode_mode)) {
4996		if (need_send_hole(sctx)) {
4997			if (sctx->cur_inode_last_extent == (u64)-1 ||
4998			    sctx->cur_inode_last_extent <
4999			    sctx->cur_inode_size) {
5000				ret = get_last_extent(sctx, (u64)-1);
5001				if (ret)
5002					goto out;
5003			}
5004			if (sctx->cur_inode_last_extent <
5005			    sctx->cur_inode_size) {
5006				ret = send_hole(sctx, sctx->cur_inode_size);
5007				if (ret)
 
5008					goto out;
 
 
 
 
 
 
 
 
5009			}
5010		}
5011		ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5012				sctx->cur_inode_size);
5013		if (ret < 0)
5014			goto out;
 
 
 
5015	}
5016
5017	if (need_chown) {
5018		ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5019				left_uid, left_gid);
5020		if (ret < 0)
5021			goto out;
5022	}
5023	if (need_chmod) {
5024		ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
5025				left_mode);
5026		if (ret < 0)
5027			goto out;
5028	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5029
5030	/*
5031	 * If other directory inodes depended on our current directory
5032	 * inode's move/rename, now do their move/rename operations.
5033	 */
5034	if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
5035		ret = apply_children_dir_moves(sctx);
5036		if (ret)
5037			goto out;
5038		/*
5039		 * Need to send that every time, no matter if it actually
5040		 * changed between the two trees as we have done changes to
5041		 * the inode before. If our inode is a directory and it's
5042		 * waiting to be moved/renamed, we will send its utimes when
5043		 * it's moved/renamed, therefore we don't need to do it here.
5044		 */
5045		sctx->send_progress = sctx->cur_ino + 1;
5046		ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
 
 
 
 
 
 
 
 
 
 
 
5047		if (ret < 0)
5048			goto out;
5049	}
5050
5051out:
 
 
 
5052	return ret;
5053}
5054
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5055static int changed_inode(struct send_ctx *sctx,
5056			 enum btrfs_compare_tree_result result)
5057{
5058	int ret = 0;
5059	struct btrfs_key *key = sctx->cmp_key;
5060	struct btrfs_inode_item *left_ii = NULL;
5061	struct btrfs_inode_item *right_ii = NULL;
5062	u64 left_gen = 0;
5063	u64 right_gen = 0;
5064
 
 
5065	sctx->cur_ino = key->objectid;
5066	sctx->cur_inode_new_gen = 0;
5067	sctx->cur_inode_last_extent = (u64)-1;
 
 
5068
5069	/*
5070	 * Set send_progress to current inode. This will tell all get_cur_xxx
5071	 * functions that the current inode's refs are not updated yet. Later,
5072	 * when process_recorded_refs is finished, it is set to cur_ino + 1.
5073	 */
5074	sctx->send_progress = sctx->cur_ino;
5075
5076	if (result == BTRFS_COMPARE_TREE_NEW ||
5077	    result == BTRFS_COMPARE_TREE_CHANGED) {
5078		left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
5079				sctx->left_path->slots[0],
5080				struct btrfs_inode_item);
5081		left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
5082				left_ii);
5083	} else {
5084		right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
5085				sctx->right_path->slots[0],
5086				struct btrfs_inode_item);
5087		right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
5088				right_ii);
5089	}
5090	if (result == BTRFS_COMPARE_TREE_CHANGED) {
5091		right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
5092				sctx->right_path->slots[0],
5093				struct btrfs_inode_item);
5094
5095		right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
5096				right_ii);
5097
5098		/*
5099		 * The cur_ino = root dir case is special here. We can't treat
5100		 * the inode as deleted+reused because it would generate a
5101		 * stream that tries to delete/mkdir the root dir.
5102		 */
5103		if (left_gen != right_gen &&
5104		    sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5105			sctx->cur_inode_new_gen = 1;
5106	}
5107
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5108	if (result == BTRFS_COMPARE_TREE_NEW) {
 
 
 
 
5109		sctx->cur_inode_gen = left_gen;
5110		sctx->cur_inode_new = 1;
5111		sctx->cur_inode_deleted = 0;
5112		sctx->cur_inode_size = btrfs_inode_size(
5113				sctx->left_path->nodes[0], left_ii);
5114		sctx->cur_inode_mode = btrfs_inode_mode(
5115				sctx->left_path->nodes[0], left_ii);
5116		sctx->cur_inode_rdev = btrfs_inode_rdev(
5117				sctx->left_path->nodes[0], left_ii);
5118		if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5119			ret = send_create_inode_if_needed(sctx);
5120	} else if (result == BTRFS_COMPARE_TREE_DELETED) {
5121		sctx->cur_inode_gen = right_gen;
5122		sctx->cur_inode_new = 0;
5123		sctx->cur_inode_deleted = 1;
5124		sctx->cur_inode_size = btrfs_inode_size(
5125				sctx->right_path->nodes[0], right_ii);
5126		sctx->cur_inode_mode = btrfs_inode_mode(
5127				sctx->right_path->nodes[0], right_ii);
5128	} else if (result == BTRFS_COMPARE_TREE_CHANGED) {
 
 
 
 
 
 
 
 
 
 
5129		/*
5130		 * We need to do some special handling in case the inode was
5131		 * reported as changed with a changed generation number. This
5132		 * means that the original inode was deleted and new inode
5133		 * reused the same inum. So we have to treat the old inode as
5134		 * deleted and the new one as new.
5135		 */
5136		if (sctx->cur_inode_new_gen) {
5137			/*
5138			 * First, process the inode as if it was deleted.
5139			 */
5140			sctx->cur_inode_gen = right_gen;
5141			sctx->cur_inode_new = 0;
5142			sctx->cur_inode_deleted = 1;
5143			sctx->cur_inode_size = btrfs_inode_size(
5144					sctx->right_path->nodes[0], right_ii);
5145			sctx->cur_inode_mode = btrfs_inode_mode(
5146					sctx->right_path->nodes[0], right_ii);
5147			ret = process_all_refs(sctx,
5148					BTRFS_COMPARE_TREE_DELETED);
5149			if (ret < 0)
5150				goto out;
 
 
5151
5152			/*
5153			 * Now process the inode as if it was new.
5154			 */
5155			sctx->cur_inode_gen = left_gen;
5156			sctx->cur_inode_new = 1;
5157			sctx->cur_inode_deleted = 0;
5158			sctx->cur_inode_size = btrfs_inode_size(
5159					sctx->left_path->nodes[0], left_ii);
5160			sctx->cur_inode_mode = btrfs_inode_mode(
5161					sctx->left_path->nodes[0], left_ii);
5162			sctx->cur_inode_rdev = btrfs_inode_rdev(
5163					sctx->left_path->nodes[0], left_ii);
5164			ret = send_create_inode_if_needed(sctx);
5165			if (ret < 0)
5166				goto out;
 
 
 
 
5167
5168			ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
5169			if (ret < 0)
5170				goto out;
5171			/*
5172			 * Advance send_progress now as we did not get into
5173			 * process_recorded_refs_if_needed in the new_gen case.
5174			 */
5175			sctx->send_progress = sctx->cur_ino + 1;
 
5176
5177			/*
5178			 * Now process all extents and xattrs of the inode as if
5179			 * they were all new.
5180			 */
5181			ret = process_all_extents(sctx);
5182			if (ret < 0)
5183				goto out;
5184			ret = process_all_new_xattrs(sctx);
5185			if (ret < 0)
5186				goto out;
 
5187		} else {
5188			sctx->cur_inode_gen = left_gen;
5189			sctx->cur_inode_new = 0;
5190			sctx->cur_inode_new_gen = 0;
5191			sctx->cur_inode_deleted = 0;
5192			sctx->cur_inode_size = btrfs_inode_size(
5193					sctx->left_path->nodes[0], left_ii);
5194			sctx->cur_inode_mode = btrfs_inode_mode(
5195					sctx->left_path->nodes[0], left_ii);
5196		}
5197	}
5198
5199out:
5200	return ret;
5201}
5202
5203/*
5204 * We have to process new refs before deleted refs, but compare_trees gives us
5205 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
5206 * first and later process them in process_recorded_refs.
5207 * For the cur_inode_new_gen case, we skip recording completely because
5208 * changed_inode did already initiate processing of refs. The reason for this is
5209 * that in this case, compare_tree actually compares the refs of 2 different
5210 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
5211 * refs of the right tree as deleted and all refs of the left tree as new.
5212 */
5213static int changed_ref(struct send_ctx *sctx,
5214		       enum btrfs_compare_tree_result result)
5215{
5216	int ret = 0;
5217
5218	BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
 
 
 
5219
5220	if (!sctx->cur_inode_new_gen &&
5221	    sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
5222		if (result == BTRFS_COMPARE_TREE_NEW)
5223			ret = record_new_ref(sctx);
5224		else if (result == BTRFS_COMPARE_TREE_DELETED)
5225			ret = record_deleted_ref(sctx);
5226		else if (result == BTRFS_COMPARE_TREE_CHANGED)
5227			ret = record_changed_ref(sctx);
5228	}
5229
5230	return ret;
5231}
5232
5233/*
5234 * Process new/deleted/changed xattrs. We skip processing in the
5235 * cur_inode_new_gen case because changed_inode did already initiate processing
5236 * of xattrs. The reason is the same as in changed_ref
5237 */
5238static int changed_xattr(struct send_ctx *sctx,
5239			 enum btrfs_compare_tree_result result)
5240{
5241	int ret = 0;
5242
5243	BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
 
 
 
5244
5245	if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
5246		if (result == BTRFS_COMPARE_TREE_NEW)
5247			ret = process_new_xattr(sctx);
5248		else if (result == BTRFS_COMPARE_TREE_DELETED)
5249			ret = process_deleted_xattr(sctx);
5250		else if (result == BTRFS_COMPARE_TREE_CHANGED)
5251			ret = process_changed_xattr(sctx);
5252	}
5253
5254	return ret;
5255}
5256
5257/*
5258 * Process new/deleted/changed extents. We skip processing in the
5259 * cur_inode_new_gen case because changed_inode did already initiate processing
5260 * of extents. The reason is the same as in changed_ref
5261 */
5262static int changed_extent(struct send_ctx *sctx,
5263			  enum btrfs_compare_tree_result result)
5264{
5265	int ret = 0;
5266
5267	BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5268
5269	if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
5270		if (result != BTRFS_COMPARE_TREE_DELETED)
5271			ret = process_extent(sctx, sctx->left_path,
5272					sctx->cmp_key);
5273	}
5274
5275	return ret;
5276}
5277
 
 
 
 
 
 
 
 
 
5278static int dir_changed(struct send_ctx *sctx, u64 dir)
5279{
5280	u64 orig_gen, new_gen;
5281	int ret;
5282
5283	ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
5284			     NULL, NULL);
5285	if (ret)
5286		return ret;
5287
5288	ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
5289			     NULL, NULL, NULL);
5290	if (ret)
5291		return ret;
5292
5293	return (orig_gen != new_gen) ? 1 : 0;
5294}
5295
5296static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path,
5297			struct btrfs_key *key)
5298{
5299	struct btrfs_inode_extref *extref;
5300	struct extent_buffer *leaf;
5301	u64 dirid = 0, last_dirid = 0;
5302	unsigned long ptr;
5303	u32 item_size;
5304	u32 cur_offset = 0;
5305	int ref_name_len;
5306	int ret = 0;
5307
5308	/* Easy case, just check this one dirid */
5309	if (key->type == BTRFS_INODE_REF_KEY) {
5310		dirid = key->offset;
5311
5312		ret = dir_changed(sctx, dirid);
5313		goto out;
5314	}
5315
5316	leaf = path->nodes[0];
5317	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
5318	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
5319	while (cur_offset < item_size) {
5320		extref = (struct btrfs_inode_extref *)(ptr +
5321						       cur_offset);
5322		dirid = btrfs_inode_extref_parent(leaf, extref);
5323		ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
5324		cur_offset += ref_name_len + sizeof(*extref);
5325		if (dirid == last_dirid)
5326			continue;
5327		ret = dir_changed(sctx, dirid);
5328		if (ret)
5329			break;
5330		last_dirid = dirid;
5331	}
5332out:
5333	return ret;
5334}
5335
5336/*
5337 * Updates compare related fields in sctx and simply forwards to the actual
5338 * changed_xxx functions.
5339 */
5340static int changed_cb(struct btrfs_root *left_root,
5341		      struct btrfs_root *right_root,
5342		      struct btrfs_path *left_path,
5343		      struct btrfs_path *right_path,
5344		      struct btrfs_key *key,
5345		      enum btrfs_compare_tree_result result,
5346		      void *ctx)
5347{
5348	int ret = 0;
5349	struct send_ctx *sctx = ctx;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5350
5351	if (result == BTRFS_COMPARE_TREE_SAME) {
5352		if (key->type == BTRFS_INODE_REF_KEY ||
5353		    key->type == BTRFS_INODE_EXTREF_KEY) {
5354			ret = compare_refs(sctx, left_path, key);
5355			if (!ret)
5356				return 0;
5357			if (ret < 0)
5358				return ret;
5359		} else if (key->type == BTRFS_EXTENT_DATA_KEY) {
5360			return maybe_send_hole(sctx, left_path, key);
5361		} else {
5362			return 0;
5363		}
5364		result = BTRFS_COMPARE_TREE_CHANGED;
5365		ret = 0;
5366	}
5367
5368	sctx->left_path = left_path;
5369	sctx->right_path = right_path;
5370	sctx->cmp_key = key;
5371
5372	ret = finish_inode_if_needed(sctx, 0);
5373	if (ret < 0)
5374		goto out;
5375
5376	/* Ignore non-FS objects */
5377	if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
5378	    key->objectid == BTRFS_FREE_SPACE_OBJECTID)
5379		goto out;
5380
5381	if (key->type == BTRFS_INODE_ITEM_KEY)
5382		ret = changed_inode(sctx, result);
5383	else if (key->type == BTRFS_INODE_REF_KEY ||
5384		 key->type == BTRFS_INODE_EXTREF_KEY)
5385		ret = changed_ref(sctx, result);
5386	else if (key->type == BTRFS_XATTR_ITEM_KEY)
5387		ret = changed_xattr(sctx, result);
5388	else if (key->type == BTRFS_EXTENT_DATA_KEY)
5389		ret = changed_extent(sctx, result);
 
 
 
 
 
5390
5391out:
5392	return ret;
5393}
5394
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5395static int full_send_tree(struct send_ctx *sctx)
5396{
5397	int ret;
5398	struct btrfs_root *send_root = sctx->send_root;
5399	struct btrfs_key key;
5400	struct btrfs_key found_key;
5401	struct btrfs_path *path;
5402	struct extent_buffer *eb;
5403	int slot;
5404
5405	path = alloc_path_for_send();
5406	if (!path)
5407		return -ENOMEM;
 
5408
5409	key.objectid = BTRFS_FIRST_FREE_OBJECTID;
5410	key.type = BTRFS_INODE_ITEM_KEY;
5411	key.offset = 0;
5412
 
 
 
 
5413	ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
5414	if (ret < 0)
5415		goto out;
5416	if (ret)
5417		goto out_finish;
5418
5419	while (1) {
5420		eb = path->nodes[0];
5421		slot = path->slots[0];
5422		btrfs_item_key_to_cpu(eb, &found_key, slot);
5423
5424		ret = changed_cb(send_root, NULL, path, NULL,
5425				&found_key, BTRFS_COMPARE_TREE_NEW, sctx);
5426		if (ret < 0)
5427			goto out;
5428
5429		key.objectid = found_key.objectid;
5430		key.type = found_key.type;
5431		key.offset = found_key.offset + 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5432
5433		ret = btrfs_next_item(send_root, path);
5434		if (ret < 0)
5435			goto out;
5436		if (ret) {
5437			ret  = 0;
5438			break;
5439		}
5440	}
5441
5442out_finish:
5443	ret = finish_inode_if_needed(sctx, 1);
5444
5445out:
5446	btrfs_free_path(path);
5447	return ret;
5448}
5449
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5450static int send_subvol(struct send_ctx *sctx)
5451{
5452	int ret;
5453
5454	if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
5455		ret = send_header(sctx);
5456		if (ret < 0)
5457			goto out;
5458	}
5459
5460	ret = send_subvol_begin(sctx);
5461	if (ret < 0)
5462		goto out;
5463
5464	if (sctx->parent_root) {
5465		ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
5466				changed_cb, sctx);
5467		if (ret < 0)
5468			goto out;
5469		ret = finish_inode_if_needed(sctx, 1);
5470		if (ret < 0)
5471			goto out;
5472	} else {
5473		ret = full_send_tree(sctx);
5474		if (ret < 0)
5475			goto out;
5476	}
5477
5478out:
5479	free_recorded_refs(sctx);
5480	return ret;
5481}
5482
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5483static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
5484{
5485	spin_lock(&root->root_item_lock);
5486	root->send_in_progress--;
5487	/*
5488	 * Not much left to do, we don't know why it's unbalanced and
5489	 * can't blindly reset it to 0.
5490	 */
5491	if (root->send_in_progress < 0)
5492		btrfs_err(root->fs_info,
5493			"send_in_progres unbalanced %d root %llu\n",
5494			root->send_in_progress, root->root_key.objectid);
5495	spin_unlock(&root->root_item_lock);
5496}
5497
5498long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
 
 
 
 
 
 
 
5499{
5500	int ret = 0;
5501	struct btrfs_root *send_root;
 
5502	struct btrfs_root *clone_root;
5503	struct btrfs_fs_info *fs_info;
5504	struct btrfs_ioctl_send_args *arg = NULL;
5505	struct btrfs_key key;
5506	struct send_ctx *sctx = NULL;
5507	u32 i;
5508	u64 *clone_sources_tmp = NULL;
5509	int clone_sources_to_rollback = 0;
 
5510	int sort_clone_roots = 0;
5511	int index;
 
5512
5513	if (!capable(CAP_SYS_ADMIN))
5514		return -EPERM;
5515
5516	send_root = BTRFS_I(file_inode(mnt_file))->root;
5517	fs_info = send_root->fs_info;
5518
5519	/*
5520	 * The subvolume must remain read-only during send, protect against
5521	 * making it RW.
5522	 */
5523	spin_lock(&send_root->root_item_lock);
5524	send_root->send_in_progress++;
5525	spin_unlock(&send_root->root_item_lock);
5526
5527	/*
5528	 * This is done when we lookup the root, it should already be complete
5529	 * by the time we get here.
5530	 */
5531	WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE);
5532
5533	/*
5534	 * Userspace tools do the checks and warn the user if it's
5535	 * not RO.
5536	 */
 
 
 
 
 
5537	if (!btrfs_root_readonly(send_root)) {
5538		ret = -EPERM;
5539		goto out;
5540	}
5541
5542	arg = memdup_user(arg_, sizeof(*arg));
5543	if (IS_ERR(arg)) {
5544		ret = PTR_ERR(arg);
5545		arg = NULL;
5546		goto out;
5547	}
 
 
5548
5549	if (!access_ok(VERIFY_READ, arg->clone_sources,
5550			sizeof(*arg->clone_sources) *
5551			arg->clone_sources_count)) {
5552		ret = -EFAULT;
 
 
 
 
5553		goto out;
5554	}
5555
5556	if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
5557		ret = -EINVAL;
5558		goto out;
5559	}
5560
5561	sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
5562	if (!sctx) {
5563		ret = -ENOMEM;
5564		goto out;
5565	}
5566
5567	INIT_LIST_HEAD(&sctx->new_refs);
5568	INIT_LIST_HEAD(&sctx->deleted_refs);
5569	INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
5570	INIT_LIST_HEAD(&sctx->name_cache_list);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5571
5572	sctx->flags = arg->flags;
5573
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5574	sctx->send_filp = fget(arg->send_fd);
5575	if (!sctx->send_filp) {
5576		ret = -EBADF;
5577		goto out;
5578	}
5579
5580	sctx->send_root = send_root;
5581	sctx->clone_roots_cnt = arg->clone_sources_count;
5582
5583	sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
5584	sctx->send_buf = vmalloc(sctx->send_max_size);
5585	if (!sctx->send_buf) {
5586		ret = -ENOMEM;
5587		goto out;
5588	}
5589
5590	sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE);
5591	if (!sctx->read_buf) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5592		ret = -ENOMEM;
5593		goto out;
5594	}
5595
5596	sctx->pending_dir_moves = RB_ROOT;
5597	sctx->waiting_dir_moves = RB_ROOT;
5598	sctx->orphan_dirs = RB_ROOT;
5599
5600	sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
5601			(arg->clone_sources_count + 1));
5602	if (!sctx->clone_roots) {
5603		ret = -ENOMEM;
5604		goto out;
5605	}
5606
 
 
 
5607	if (arg->clone_sources_count) {
5608		clone_sources_tmp = vmalloc(arg->clone_sources_count *
5609				sizeof(*arg->clone_sources));
5610		if (!clone_sources_tmp) {
5611			ret = -ENOMEM;
5612			goto out;
5613		}
5614
5615		ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
5616				arg->clone_sources_count *
5617				sizeof(*arg->clone_sources));
5618		if (ret) {
5619			ret = -EFAULT;
5620			goto out;
5621		}
5622
5623		for (i = 0; i < arg->clone_sources_count; i++) {
5624			key.objectid = clone_sources_tmp[i];
5625			key.type = BTRFS_ROOT_ITEM_KEY;
5626			key.offset = (u64)-1;
5627
5628			index = srcu_read_lock(&fs_info->subvol_srcu);
5629
5630			clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
5631			if (IS_ERR(clone_root)) {
5632				srcu_read_unlock(&fs_info->subvol_srcu, index);
5633				ret = PTR_ERR(clone_root);
5634				goto out;
5635			}
5636			clone_sources_to_rollback = i + 1;
5637			spin_lock(&clone_root->root_item_lock);
5638			clone_root->send_in_progress++;
5639			if (!btrfs_root_readonly(clone_root)) {
5640				spin_unlock(&clone_root->root_item_lock);
5641				srcu_read_unlock(&fs_info->subvol_srcu, index);
5642				ret = -EPERM;
5643				goto out;
5644			}
 
 
 
 
 
 
 
 
5645			spin_unlock(&clone_root->root_item_lock);
5646			srcu_read_unlock(&fs_info->subvol_srcu, index);
5647
5648			sctx->clone_roots[i].root = clone_root;
 
5649		}
5650		vfree(clone_sources_tmp);
5651		clone_sources_tmp = NULL;
5652	}
5653
5654	if (arg->parent_root) {
5655		key.objectid = arg->parent_root;
5656		key.type = BTRFS_ROOT_ITEM_KEY;
5657		key.offset = (u64)-1;
5658
5659		index = srcu_read_lock(&fs_info->subvol_srcu);
5660
5661		sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
5662		if (IS_ERR(sctx->parent_root)) {
5663			srcu_read_unlock(&fs_info->subvol_srcu, index);
5664			ret = PTR_ERR(sctx->parent_root);
5665			goto out;
5666		}
5667
5668		spin_lock(&sctx->parent_root->root_item_lock);
5669		sctx->parent_root->send_in_progress++;
5670		if (!btrfs_root_readonly(sctx->parent_root)) {
 
5671			spin_unlock(&sctx->parent_root->root_item_lock);
5672			srcu_read_unlock(&fs_info->subvol_srcu, index);
5673			ret = -EPERM;
5674			goto out;
5675		}
 
 
 
 
 
 
5676		spin_unlock(&sctx->parent_root->root_item_lock);
5677
5678		srcu_read_unlock(&fs_info->subvol_srcu, index);
5679	}
5680
5681	/*
5682	 * Clones from send_root are allowed, but only if the clone source
5683	 * is behind the current send position. This is checked while searching
5684	 * for possible clone sources.
5685	 */
5686	sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;
 
5687
5688	/* We do a bsearch later */
5689	sort(sctx->clone_roots, sctx->clone_roots_cnt,
5690			sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
5691			NULL);
5692	sort_clone_roots = 1;
5693
5694	current->journal_info = (void *)BTRFS_SEND_TRANS_STUB;
 
 
 
 
 
 
 
5695	ret = send_subvol(sctx);
5696	current->journal_info = NULL;
5697	if (ret < 0)
5698		goto out;
5699
 
 
 
 
 
 
 
5700	if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) {
5701		ret = begin_cmd(sctx, BTRFS_SEND_C_END);
5702		if (ret < 0)
5703			goto out;
5704		ret = send_cmd(sctx);
5705		if (ret < 0)
5706			goto out;
5707	}
5708
5709out:
5710	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
5711	while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
5712		struct rb_node *n;
5713		struct pending_dir_move *pm;
5714
5715		n = rb_first(&sctx->pending_dir_moves);
5716		pm = rb_entry(n, struct pending_dir_move, node);
5717		while (!list_empty(&pm->list)) {
5718			struct pending_dir_move *pm2;
5719
5720			pm2 = list_first_entry(&pm->list,
5721					       struct pending_dir_move, list);
5722			free_pending_move(sctx, pm2);
5723		}
5724		free_pending_move(sctx, pm);
5725	}
5726
5727	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
5728	while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
5729		struct rb_node *n;
5730		struct waiting_dir_move *dm;
5731
5732		n = rb_first(&sctx->waiting_dir_moves);
5733		dm = rb_entry(n, struct waiting_dir_move, node);
5734		rb_erase(&dm->node, &sctx->waiting_dir_moves);
5735		kfree(dm);
5736	}
5737
5738	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->orphan_dirs));
5739	while (sctx && !RB_EMPTY_ROOT(&sctx->orphan_dirs)) {
5740		struct rb_node *n;
5741		struct orphan_dir_info *odi;
5742
5743		n = rb_first(&sctx->orphan_dirs);
5744		odi = rb_entry(n, struct orphan_dir_info, node);
5745		free_orphan_dir_info(sctx, odi);
5746	}
5747
5748	if (sort_clone_roots) {
5749		for (i = 0; i < sctx->clone_roots_cnt; i++)
5750			btrfs_root_dec_send_in_progress(
5751					sctx->clone_roots[i].root);
 
 
5752	} else {
5753		for (i = 0; sctx && i < clone_sources_to_rollback; i++)
5754			btrfs_root_dec_send_in_progress(
5755					sctx->clone_roots[i].root);
 
 
5756
5757		btrfs_root_dec_send_in_progress(send_root);
5758	}
5759	if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
5760		btrfs_root_dec_send_in_progress(sctx->parent_root);
 
 
5761
5762	kfree(arg);
5763	vfree(clone_sources_tmp);
5764
5765	if (sctx) {
5766		if (sctx->send_filp)
5767			fput(sctx->send_filp);
5768
5769		vfree(sctx->clone_roots);
5770		vfree(sctx->send_buf);
5771		vfree(sctx->read_buf);
5772
5773		name_cache_free(sctx);
 
 
 
 
 
 
5774
5775		kfree(sctx);
5776	}
5777
5778	return ret;
5779}