send.c 133.1 KB
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/*
 * Copyright (C) 2012 Alexander Block.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/bsearch.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/sort.h>
#include <linux/mount.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/radix-tree.h>
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#include <linux/vmalloc.h>
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#include <linux/string.h>
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#include "send.h"
#include "backref.h"
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#include "hash.h"
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#include "locking.h"
#include "disk-io.h"
#include "btrfs_inode.h"
#include "transaction.h"

static int g_verbose = 0;

#define verbose_printk(...) if (g_verbose) printk(__VA_ARGS__)

/*
 * A fs_path is a helper to dynamically build path names with unknown size.
 * It reallocates the internal buffer on demand.
 * It allows fast adding of path elements on the right side (normal path) and
 * fast adding to the left side (reversed path). A reversed path can also be
 * unreversed if needed.
 */
struct fs_path {
	union {
		struct {
			char *start;
			char *end;

			char *buf;
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			unsigned short buf_len:15;
			unsigned short reversed:1;
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			char inline_buf[];
		};
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		/*
		 * Average path length does not exceed 200 bytes, we'll have
		 * better packing in the slab and higher chance to satisfy
		 * a allocation later during send.
		 */
		char pad[256];
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	};
};
#define FS_PATH_INLINE_SIZE \
	(sizeof(struct fs_path) - offsetof(struct fs_path, inline_buf))


/* reused for each extent */
struct clone_root {
	struct btrfs_root *root;
	u64 ino;
	u64 offset;

	u64 found_refs;
};

#define SEND_CTX_MAX_NAME_CACHE_SIZE 128
#define SEND_CTX_NAME_CACHE_CLEAN_SIZE (SEND_CTX_MAX_NAME_CACHE_SIZE * 2)

struct send_ctx {
	struct file *send_filp;
	loff_t send_off;
	char *send_buf;
	u32 send_size;
	u32 send_max_size;
	u64 total_send_size;
	u64 cmd_send_size[BTRFS_SEND_C_MAX + 1];
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	u64 flags;	/* 'flags' member of btrfs_ioctl_send_args is u64 */
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	struct btrfs_root *send_root;
	struct btrfs_root *parent_root;
	struct clone_root *clone_roots;
	int clone_roots_cnt;

	/* current state of the compare_tree call */
	struct btrfs_path *left_path;
	struct btrfs_path *right_path;
	struct btrfs_key *cmp_key;

	/*
	 * infos of the currently processed inode. In case of deleted inodes,
	 * these are the values from the deleted inode.
	 */
	u64 cur_ino;
	u64 cur_inode_gen;
	int cur_inode_new;
	int cur_inode_new_gen;
	int cur_inode_deleted;
	u64 cur_inode_size;
	u64 cur_inode_mode;
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	u64 cur_inode_rdev;
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	u64 cur_inode_last_extent;
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	u64 send_progress;

	struct list_head new_refs;
	struct list_head deleted_refs;

	struct radix_tree_root name_cache;
	struct list_head name_cache_list;
	int name_cache_size;

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	struct file_ra_state ra;

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	char *read_buf;
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	/*
	 * We process inodes by their increasing order, so if before an
	 * incremental send we reverse the parent/child relationship of
	 * directories such that a directory with a lower inode number was
	 * the parent of a directory with a higher inode number, and the one
	 * becoming the new parent got renamed too, we can't rename/move the
	 * directory with lower inode number when we finish processing it - we
	 * must process the directory with higher inode number first, then
	 * rename/move it and then rename/move the directory with lower inode
	 * number. Example follows.
	 *
	 * Tree state when the first send was performed:
	 *
	 * .
	 * |-- a                   (ino 257)
	 *     |-- b               (ino 258)
	 *         |
	 *         |
	 *         |-- c           (ino 259)
	 *         |   |-- d       (ino 260)
	 *         |
	 *         |-- c2          (ino 261)
	 *
	 * Tree state when the second (incremental) send is performed:
	 *
	 * .
	 * |-- a                   (ino 257)
	 *     |-- b               (ino 258)
	 *         |-- c2          (ino 261)
	 *             |-- d2      (ino 260)
	 *                 |-- cc  (ino 259)
	 *
	 * The sequence of steps that lead to the second state was:
	 *
	 * mv /a/b/c/d /a/b/c2/d2
	 * mv /a/b/c /a/b/c2/d2/cc
	 *
	 * "c" has lower inode number, but we can't move it (2nd mv operation)
	 * before we move "d", which has higher inode number.
	 *
	 * So we just memorize which move/rename operations must be performed
	 * later when their respective parent is processed and moved/renamed.
	 */

	/* Indexed by parent directory inode number. */
	struct rb_root pending_dir_moves;

	/*
	 * Reverse index, indexed by the inode number of a directory that
	 * is waiting for the move/rename of its immediate parent before its
	 * own move/rename can be performed.
	 */
	struct rb_root waiting_dir_moves;
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	/*
	 * A directory that is going to be rm'ed might have a child directory
	 * which is in the pending directory moves index above. In this case,
	 * the directory can only be removed after the move/rename of its child
	 * is performed. Example:
	 *
	 * Parent snapshot:
	 *
	 * .                        (ino 256)
	 * |-- a/                   (ino 257)
	 *     |-- b/               (ino 258)
	 *         |-- c/           (ino 259)
	 *         |   |-- x/       (ino 260)
	 *         |
	 *         |-- y/           (ino 261)
	 *
	 * Send snapshot:
	 *
	 * .                        (ino 256)
	 * |-- a/                   (ino 257)
	 *     |-- b/               (ino 258)
	 *         |-- YY/          (ino 261)
	 *              |-- x/      (ino 260)
	 *
	 * Sequence of steps that lead to the send snapshot:
	 * rm -f /a/b/c/foo.txt
	 * mv /a/b/y /a/b/YY
	 * mv /a/b/c/x /a/b/YY
	 * rmdir /a/b/c
	 *
	 * When the child is processed, its move/rename is delayed until its
	 * parent is processed (as explained above), but all other operations
	 * like update utimes, chown, chgrp, etc, are performed and the paths
	 * that it uses for those operations must use the orphanized name of
	 * its parent (the directory we're going to rm later), so we need to
	 * memorize that name.
	 *
	 * Indexed by the inode number of the directory to be deleted.
	 */
	struct rb_root orphan_dirs;
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};

struct pending_dir_move {
	struct rb_node node;
	struct list_head list;
	u64 parent_ino;
	u64 ino;
	u64 gen;
	struct list_head update_refs;
};

struct waiting_dir_move {
	struct rb_node node;
	u64 ino;
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	/*
	 * There might be some directory that could not be removed because it
	 * was waiting for this directory inode to be moved first. Therefore
	 * after this directory is moved, we can try to rmdir the ino rmdir_ino.
	 */
	u64 rmdir_ino;
};

struct orphan_dir_info {
	struct rb_node node;
	u64 ino;
	u64 gen;
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};

struct name_cache_entry {
	struct list_head list;
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	/*
	 * radix_tree has only 32bit entries but we need to handle 64bit inums.
	 * We use the lower 32bit of the 64bit inum to store it in the tree. If
	 * more then one inum would fall into the same entry, we use radix_list
	 * to store the additional entries. radix_list is also used to store
	 * entries where two entries have the same inum but different
	 * generations.
	 */
	struct list_head radix_list;
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	u64 ino;
	u64 gen;
	u64 parent_ino;
	u64 parent_gen;
	int ret;
	int need_later_update;
	int name_len;
	char name[];
};

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static int is_waiting_for_move(struct send_ctx *sctx, u64 ino);

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static struct waiting_dir_move *
get_waiting_dir_move(struct send_ctx *sctx, u64 ino);

static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino);

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static int need_send_hole(struct send_ctx *sctx)
{
	return (sctx->parent_root && !sctx->cur_inode_new &&
		!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted &&
		S_ISREG(sctx->cur_inode_mode));
}

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static void fs_path_reset(struct fs_path *p)
{
	if (p->reversed) {
		p->start = p->buf + p->buf_len - 1;
		p->end = p->start;
		*p->start = 0;
	} else {
		p->start = p->buf;
		p->end = p->start;
		*p->start = 0;
	}
}

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static struct fs_path *fs_path_alloc(void)
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{
	struct fs_path *p;

	p = kmalloc(sizeof(*p), GFP_NOFS);
	if (!p)
		return NULL;
	p->reversed = 0;
	p->buf = p->inline_buf;
	p->buf_len = FS_PATH_INLINE_SIZE;
	fs_path_reset(p);
	return p;
}

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static struct fs_path *fs_path_alloc_reversed(void)
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{
	struct fs_path *p;

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	p = fs_path_alloc();
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	if (!p)
		return NULL;
	p->reversed = 1;
	fs_path_reset(p);
	return p;
}

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static void fs_path_free(struct fs_path *p)
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{
	if (!p)
		return;
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	if (p->buf != p->inline_buf)
		kfree(p->buf);
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	kfree(p);
}

static int fs_path_len(struct fs_path *p)
{
	return p->end - p->start;
}

static int fs_path_ensure_buf(struct fs_path *p, int len)
{
	char *tmp_buf;
	int path_len;
	int old_buf_len;

	len++;

	if (p->buf_len >= len)
		return 0;

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	path_len = p->end - p->start;
	old_buf_len = p->buf_len;

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	/*
	 * First time the inline_buf does not suffice
	 */
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	if (p->buf == p->inline_buf)
		tmp_buf = kmalloc(len, GFP_NOFS);
	else
		tmp_buf = krealloc(p->buf, len, GFP_NOFS);
	if (!tmp_buf)
		return -ENOMEM;
	p->buf = tmp_buf;
	/*
	 * The real size of the buffer is bigger, this will let the fast path
	 * happen most of the time
	 */
	p->buf_len = ksize(p->buf);
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	if (p->reversed) {
		tmp_buf = p->buf + old_buf_len - path_len - 1;
		p->end = p->buf + p->buf_len - 1;
		p->start = p->end - path_len;
		memmove(p->start, tmp_buf, path_len + 1);
	} else {
		p->start = p->buf;
		p->end = p->start + path_len;
	}
	return 0;
}

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static int fs_path_prepare_for_add(struct fs_path *p, int name_len,
				   char **prepared)
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{
	int ret;
	int new_len;

	new_len = p->end - p->start + name_len;
	if (p->start != p->end)
		new_len++;
	ret = fs_path_ensure_buf(p, new_len);
	if (ret < 0)
		goto out;

	if (p->reversed) {
		if (p->start != p->end)
			*--p->start = '/';
		p->start -= name_len;
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		*prepared = p->start;
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	} else {
		if (p->start != p->end)
			*p->end++ = '/';
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		*prepared = p->end;
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		p->end += name_len;
		*p->end = 0;
	}

out:
	return ret;
}

static int fs_path_add(struct fs_path *p, const char *name, int name_len)
{
	int ret;
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	char *prepared;
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	ret = fs_path_prepare_for_add(p, name_len, &prepared);
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	if (ret < 0)
		goto out;
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	memcpy(prepared, name, name_len);
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out:
	return ret;
}

static int fs_path_add_path(struct fs_path *p, struct fs_path *p2)
{
	int ret;
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	char *prepared;
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	ret = fs_path_prepare_for_add(p, p2->end - p2->start, &prepared);
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	if (ret < 0)
		goto out;
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	memcpy(prepared, p2->start, p2->end - p2->start);
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out:
	return ret;
}

static int fs_path_add_from_extent_buffer(struct fs_path *p,
					  struct extent_buffer *eb,
					  unsigned long off, int len)
{
	int ret;
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	char *prepared;
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	ret = fs_path_prepare_for_add(p, len, &prepared);
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	if (ret < 0)
		goto out;

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	read_extent_buffer(eb, prepared, off, len);
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out:
	return ret;
}

static int fs_path_copy(struct fs_path *p, struct fs_path *from)
{
	int ret;

	p->reversed = from->reversed;
	fs_path_reset(p);

	ret = fs_path_add_path(p, from);

	return ret;
}


static void fs_path_unreverse(struct fs_path *p)
{
	char *tmp;
	int len;

	if (!p->reversed)
		return;

	tmp = p->start;
	len = p->end - p->start;
	p->start = p->buf;
	p->end = p->start + len;
	memmove(p->start, tmp, len + 1);
	p->reversed = 0;
}

static struct btrfs_path *alloc_path_for_send(void)
{
	struct btrfs_path *path;

	path = btrfs_alloc_path();
	if (!path)
		return NULL;
	path->search_commit_root = 1;
	path->skip_locking = 1;
	return path;
}

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static int write_buf(struct file *filp, const void *buf, u32 len, loff_t *off)
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{
	int ret;
	mm_segment_t old_fs;
	u32 pos = 0;

	old_fs = get_fs();
	set_fs(KERNEL_DS);

	while (pos < len) {
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		ret = vfs_write(filp, (char *)buf + pos, len - pos, off);
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		/* TODO handle that correctly */
		/*if (ret == -ERESTARTSYS) {
			continue;
		}*/
		if (ret < 0)
			goto out;
		if (ret == 0) {
			ret = -EIO;
			goto out;
		}
		pos += ret;
	}

	ret = 0;

out:
	set_fs(old_fs);
	return ret;
}

static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len)
{
	struct btrfs_tlv_header *hdr;
	int total_len = sizeof(*hdr) + len;
	int left = sctx->send_max_size - sctx->send_size;

	if (unlikely(left < total_len))
		return -EOVERFLOW;

	hdr = (struct btrfs_tlv_header *) (sctx->send_buf + sctx->send_size);
	hdr->tlv_type = cpu_to_le16(attr);
	hdr->tlv_len = cpu_to_le16(len);
	memcpy(hdr + 1, data, len);
	sctx->send_size += total_len;

	return 0;
}

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#define TLV_PUT_DEFINE_INT(bits) \
	static int tlv_put_u##bits(struct send_ctx *sctx,	 	\
			u##bits attr, u##bits value)			\
	{								\
		__le##bits __tmp = cpu_to_le##bits(value);		\
		return tlv_put(sctx, attr, &__tmp, sizeof(__tmp));	\
	}
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TLV_PUT_DEFINE_INT(64)
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static int tlv_put_string(struct send_ctx *sctx, u16 attr,
			  const char *str, int len)
{
	if (len == -1)
		len = strlen(str);
	return tlv_put(sctx, attr, str, len);
}

static int tlv_put_uuid(struct send_ctx *sctx, u16 attr,
			const u8 *uuid)
{
	return tlv_put(sctx, attr, uuid, BTRFS_UUID_SIZE);
}

static int tlv_put_btrfs_timespec(struct send_ctx *sctx, u16 attr,
				  struct extent_buffer *eb,
				  struct btrfs_timespec *ts)
{
	struct btrfs_timespec bts;
	read_extent_buffer(eb, &bts, (unsigned long)ts, sizeof(bts));
	return tlv_put(sctx, attr, &bts, sizeof(bts));
}


#define TLV_PUT(sctx, attrtype, attrlen, data) \
	do { \
		ret = tlv_put(sctx, attrtype, attrlen, data); \
		if (ret < 0) \
			goto tlv_put_failure; \
	} while (0)

#define TLV_PUT_INT(sctx, attrtype, bits, value) \
	do { \
		ret = tlv_put_u##bits(sctx, attrtype, value); \
		if (ret < 0) \
			goto tlv_put_failure; \
	} while (0)

#define TLV_PUT_U8(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 8, data)
#define TLV_PUT_U16(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 16, data)
#define TLV_PUT_U32(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 32, data)
#define TLV_PUT_U64(sctx, attrtype, data) TLV_PUT_INT(sctx, attrtype, 64, data)
#define TLV_PUT_STRING(sctx, attrtype, str, len) \
	do { \
		ret = tlv_put_string(sctx, attrtype, str, len); \
		if (ret < 0) \
			goto tlv_put_failure; \
	} while (0)
#define TLV_PUT_PATH(sctx, attrtype, p) \
	do { \
		ret = tlv_put_string(sctx, attrtype, p->start, \
			p->end - p->start); \
		if (ret < 0) \
			goto tlv_put_failure; \
	} while(0)
#define TLV_PUT_UUID(sctx, attrtype, uuid) \
	do { \
		ret = tlv_put_uuid(sctx, attrtype, uuid); \
		if (ret < 0) \
			goto tlv_put_failure; \
	} while (0)
#define TLV_PUT_BTRFS_TIMESPEC(sctx, attrtype, eb, ts) \
	do { \
		ret = tlv_put_btrfs_timespec(sctx, attrtype, eb, ts); \
		if (ret < 0) \
			goto tlv_put_failure; \
	} while (0)

static int send_header(struct send_ctx *sctx)
{
	struct btrfs_stream_header hdr;

	strcpy(hdr.magic, BTRFS_SEND_STREAM_MAGIC);
	hdr.version = cpu_to_le32(BTRFS_SEND_STREAM_VERSION);

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	return write_buf(sctx->send_filp, &hdr, sizeof(hdr),
					&sctx->send_off);
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}

/*
 * For each command/item we want to send to userspace, we call this function.
 */
static int begin_cmd(struct send_ctx *sctx, int cmd)
{
	struct btrfs_cmd_header *hdr;

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	if (WARN_ON(!sctx->send_buf))
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		return -EINVAL;

	BUG_ON(sctx->send_size);

	sctx->send_size += sizeof(*hdr);
	hdr = (struct btrfs_cmd_header *)sctx->send_buf;
	hdr->cmd = cpu_to_le16(cmd);

	return 0;
}

static int send_cmd(struct send_ctx *sctx)
{
	int ret;
	struct btrfs_cmd_header *hdr;
	u32 crc;

	hdr = (struct btrfs_cmd_header *)sctx->send_buf;
	hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
	hdr->crc = 0;

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	crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
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	hdr->crc = cpu_to_le32(crc);

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	ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
					&sctx->send_off);
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	sctx->total_send_size += sctx->send_size;
	sctx->cmd_send_size[le16_to_cpu(hdr->cmd)] += sctx->send_size;
	sctx->send_size = 0;

	return ret;
}

/*
 * Sends a move instruction to user space
 */
static int send_rename(struct send_ctx *sctx,
		     struct fs_path *from, struct fs_path *to)
{
	int ret;

verbose_printk("btrfs: send_rename %s -> %s\n", from->start, to->start);

	ret = begin_cmd(sctx, BTRFS_SEND_C_RENAME);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, from);
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_TO, to);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
	return ret;
}

/*
 * Sends a link instruction to user space
 */
static int send_link(struct send_ctx *sctx,
		     struct fs_path *path, struct fs_path *lnk)
{
	int ret;

verbose_printk("btrfs: send_link %s -> %s\n", path->start, lnk->start);

	ret = begin_cmd(sctx, BTRFS_SEND_C_LINK);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, lnk);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
	return ret;
}

/*
 * Sends an unlink instruction to user space
 */
static int send_unlink(struct send_ctx *sctx, struct fs_path *path)
{
	int ret;

verbose_printk("btrfs: send_unlink %s\n", path->start);

	ret = begin_cmd(sctx, BTRFS_SEND_C_UNLINK);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
	return ret;
}

/*
 * Sends a rmdir instruction to user space
 */
static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
{
	int ret;

verbose_printk("btrfs: send_rmdir %s\n", path->start);

	ret = begin_cmd(sctx, BTRFS_SEND_C_RMDIR);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
	return ret;
}

/*
 * Helper function to retrieve some fields from an inode item.
 */
static int get_inode_info(struct btrfs_root *root,
			  u64 ino, u64 *size, u64 *gen,
776 777
			  u64 *mode, u64 *uid, u64 *gid,
			  u64 *rdev)
778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810
{
	int ret;
	struct btrfs_inode_item *ii;
	struct btrfs_key key;
	struct btrfs_path *path;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	key.objectid = ino;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	if (ret) {
		ret = -ENOENT;
		goto out;
	}

	ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
			struct btrfs_inode_item);
	if (size)
		*size = btrfs_inode_size(path->nodes[0], ii);
	if (gen)
		*gen = btrfs_inode_generation(path->nodes[0], ii);
	if (mode)
		*mode = btrfs_inode_mode(path->nodes[0], ii);
	if (uid)
		*uid = btrfs_inode_uid(path->nodes[0], ii);
	if (gid)
		*gid = btrfs_inode_gid(path->nodes[0], ii);
811 812
	if (rdev)
		*rdev = btrfs_inode_rdev(path->nodes[0], ii);
813 814 815 816 817 818 819 820 821 822 823

out:
	btrfs_free_path(path);
	return ret;
}

typedef int (*iterate_inode_ref_t)(int num, u64 dir, int index,
				   struct fs_path *p,
				   void *ctx);

/*
824 825
 * Helper function to iterate the entries in ONE btrfs_inode_ref or
 * btrfs_inode_extref.
826 827 828
 * The iterate callback may return a non zero value to stop iteration. This can
 * be a negative value for error codes or 1 to simply stop it.
 *
829
 * path must point to the INODE_REF or INODE_EXTREF when called.
830
 */
831
static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
832 833 834
			     struct btrfs_key *found_key, int resolve,
			     iterate_inode_ref_t iterate, void *ctx)
{
835
	struct extent_buffer *eb = path->nodes[0];
836 837
	struct btrfs_item *item;
	struct btrfs_inode_ref *iref;
838
	struct btrfs_inode_extref *extref;
839 840
	struct btrfs_path *tmp_path;
	struct fs_path *p;
841
	u32 cur = 0;
842
	u32 total;
843
	int slot = path->slots[0];
844 845 846
	u32 name_len;
	char *start;
	int ret = 0;
847
	int num = 0;
848
	int index;
849 850 851 852
	u64 dir;
	unsigned long name_off;
	unsigned long elem_size;
	unsigned long ptr;
853

854
	p = fs_path_alloc_reversed();
855 856 857 858 859
	if (!p)
		return -ENOMEM;

	tmp_path = alloc_path_for_send();
	if (!tmp_path) {
860
		fs_path_free(p);
861 862 863 864
		return -ENOMEM;
	}


865 866 867
	if (found_key->type == BTRFS_INODE_REF_KEY) {
		ptr = (unsigned long)btrfs_item_ptr(eb, slot,
						    struct btrfs_inode_ref);
868
		item = btrfs_item_nr(slot);
869 870 871 872 873 874 875 876
		total = btrfs_item_size(eb, item);
		elem_size = sizeof(*iref);
	} else {
		ptr = btrfs_item_ptr_offset(eb, slot);
		total = btrfs_item_size_nr(eb, slot);
		elem_size = sizeof(*extref);
	}

877 878 879
	while (cur < total) {
		fs_path_reset(p);

880 881 882 883 884 885 886 887 888 889 890 891 892 893
		if (found_key->type == BTRFS_INODE_REF_KEY) {
			iref = (struct btrfs_inode_ref *)(ptr + cur);
			name_len = btrfs_inode_ref_name_len(eb, iref);
			name_off = (unsigned long)(iref + 1);
			index = btrfs_inode_ref_index(eb, iref);
			dir = found_key->offset;
		} else {
			extref = (struct btrfs_inode_extref *)(ptr + cur);
			name_len = btrfs_inode_extref_name_len(eb, extref);
			name_off = (unsigned long)&extref->name;
			index = btrfs_inode_extref_index(eb, extref);
			dir = btrfs_inode_extref_parent(eb, extref);
		}

894
		if (resolve) {
895 896 897
			start = btrfs_ref_to_path(root, tmp_path, name_len,
						  name_off, eb, dir,
						  p->buf, p->buf_len);
898 899 900 901 902 903 904 905 906 907
			if (IS_ERR(start)) {
				ret = PTR_ERR(start);
				goto out;
			}
			if (start < p->buf) {
				/* overflow , try again with larger buffer */
				ret = fs_path_ensure_buf(p,
						p->buf_len + p->buf - start);
				if (ret < 0)
					goto out;
908 909 910 911
				start = btrfs_ref_to_path(root, tmp_path,
							  name_len, name_off,
							  eb, dir,
							  p->buf, p->buf_len);
912 913 914 915 916 917 918 919
				if (IS_ERR(start)) {
					ret = PTR_ERR(start);
					goto out;
				}
				BUG_ON(start < p->buf);
			}
			p->start = start;
		} else {
920 921
			ret = fs_path_add_from_extent_buffer(p, eb, name_off,
							     name_len);
922 923 924 925
			if (ret < 0)
				goto out;
		}

926 927
		cur += elem_size + name_len;
		ret = iterate(num, dir, index, p, ctx);
928 929 930 931 932 933 934
		if (ret)
			goto out;
		num++;
	}

out:
	btrfs_free_path(tmp_path);
935
	fs_path_free(p);
936 937 938 939 940 941 942 943 944 945 946 947 948 949 950
	return ret;
}

typedef int (*iterate_dir_item_t)(int num, struct btrfs_key *di_key,
				  const char *name, int name_len,
				  const char *data, int data_len,
				  u8 type, void *ctx);

/*
 * Helper function to iterate the entries in ONE btrfs_dir_item.
 * The iterate callback may return a non zero value to stop iteration. This can
 * be a negative value for error codes or 1 to simply stop it.
 *
 * path must point to the dir item when called.
 */
951
static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
952 953 954 955 956 957 958 959 960
			    struct btrfs_key *found_key,
			    iterate_dir_item_t iterate, void *ctx)
{
	int ret = 0;
	struct extent_buffer *eb;
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key di_key;
	char *buf = NULL;
961
	const int buf_len = PATH_MAX;
962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978
	u32 name_len;
	u32 data_len;
	u32 cur;
	u32 len;
	u32 total;
	int slot;
	int num;
	u8 type;

	buf = kmalloc(buf_len, GFP_NOFS);
	if (!buf) {
		ret = -ENOMEM;
		goto out;
	}

	eb = path->nodes[0];
	slot = path->slots[0];
979
	item = btrfs_item_nr(slot);
980 981 982 983 984 985 986 987 988 989 990 991
	di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
	cur = 0;
	len = 0;
	total = btrfs_item_size(eb, item);

	num = 0;
	while (cur < total) {
		name_len = btrfs_dir_name_len(eb, di);
		data_len = btrfs_dir_data_len(eb, di);
		type = btrfs_dir_type(eb, di);
		btrfs_dir_item_key_to_cpu(eb, di, &di_key);

992 993 994
		/*
		 * Path too long
		 */
995
		if (name_len + data_len > buf_len) {
996 997
			ret = -ENAMETOOLONG;
			goto out;
998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019
		}

		read_extent_buffer(eb, buf, (unsigned long)(di + 1),
				name_len + data_len);

		len = sizeof(*di) + name_len + data_len;
		di = (struct btrfs_dir_item *)((char *)di + len);
		cur += len;

		ret = iterate(num, &di_key, buf, name_len, buf + name_len,
				data_len, type, ctx);
		if (ret < 0)
			goto out;
		if (ret) {
			ret = 0;
			goto out;
		}

		num++;
	}

out:
1020
	kfree(buf);
1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
	return ret;
}

static int __copy_first_ref(int num, u64 dir, int index,
			    struct fs_path *p, void *ctx)
{
	int ret;
	struct fs_path *pt = ctx;

	ret = fs_path_copy(pt, p);
	if (ret < 0)
		return ret;

	/* we want the first only */
	return 1;
}

/*
 * Retrieve the first path of an inode. If an inode has more then one
 * ref/hardlink, this is ignored.
 */
1042
static int get_inode_path(struct btrfs_root *root,
1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067
			  u64 ino, struct fs_path *path)
{
	int ret;
	struct btrfs_key key, found_key;
	struct btrfs_path *p;

	p = alloc_path_for_send();
	if (!p)
		return -ENOMEM;

	fs_path_reset(path);

	key.objectid = ino;
	key.type = BTRFS_INODE_REF_KEY;
	key.offset = 0;

	ret = btrfs_search_slot_for_read(root, &key, p, 1, 0);
	if (ret < 0)
		goto out;
	if (ret) {
		ret = 1;
		goto out;
	}
	btrfs_item_key_to_cpu(p->nodes[0], &found_key, p->slots[0]);
	if (found_key.objectid != ino ||
1068 1069
	    (found_key.type != BTRFS_INODE_REF_KEY &&
	     found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1070 1071 1072 1073
		ret = -ENOENT;
		goto out;
	}

1074 1075
	ret = iterate_inode_ref(root, p, &found_key, 1,
				__copy_first_ref, path);
1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101
	if (ret < 0)
		goto out;
	ret = 0;

out:
	btrfs_free_path(p);
	return ret;
}

struct backref_ctx {
	struct send_ctx *sctx;

	/* number of total found references */
	u64 found;

	/*
	 * used for clones found in send_root. clones found behind cur_objectid
	 * and cur_offset are not considered as allowed clones.
	 */
	u64 cur_objectid;
	u64 cur_offset;

	/* may be truncated in case it's the last extent in a file */
	u64 extent_len;

	/* Just to check for bugs in backref resolving */
1102
	int found_itself;
1103 1104 1105 1106
};

static int __clone_root_cmp_bsearch(const void *key, const void *elt)
{
1107
	u64 root = (u64)(uintptr_t)key;
1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
	struct clone_root *cr = (struct clone_root *)elt;

	if (root < cr->root->objectid)
		return -1;
	if (root > cr->root->objectid)
		return 1;
	return 0;
}

static int __clone_root_cmp_sort(const void *e1, const void *e2)
{
	struct clone_root *cr1 = (struct clone_root *)e1;
	struct clone_root *cr2 = (struct clone_root *)e2;

	if (cr1->root->objectid < cr2->root->objectid)
		return -1;
	if (cr1->root->objectid > cr2->root->objectid)
		return 1;
	return 0;
}

/*
 * Called for every backref that is found for the current extent.
1131
 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1132 1133 1134 1135 1136 1137 1138 1139 1140
 */
static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
{
	struct backref_ctx *bctx = ctx_;
	struct clone_root *found;
	int ret;
	u64 i_size;

	/* First check if the root is in the list of accepted clone sources */
1141
	found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1142 1143 1144 1145 1146 1147 1148 1149 1150
			bctx->sctx->clone_roots_cnt,
			sizeof(struct clone_root),
			__clone_root_cmp_bsearch);
	if (!found)
		return 0;

	if (found->root == bctx->sctx->send_root &&
	    ino == bctx->cur_objectid &&
	    offset == bctx->cur_offset) {
1151
		bctx->found_itself = 1;
1152 1153 1154
	}

	/*
1155
	 * There are inodes that have extents that lie behind its i_size. Don't
1156 1157
	 * accept clones from these extents.
	 */
1158 1159
	ret = get_inode_info(found->root, ino, &i_size, NULL, NULL, NULL, NULL,
			NULL);
1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178
	if (ret < 0)
		return ret;

	if (offset + bctx->extent_len > i_size)
		return 0;

	/*
	 * Make sure we don't consider clones from send_root that are
	 * behind the current inode/offset.
	 */
	if (found->root == bctx->sctx->send_root) {
		/*
		 * TODO for the moment we don't accept clones from the inode
		 * that is currently send. We may change this when
		 * BTRFS_IOC_CLONE_RANGE supports cloning from and to the same
		 * file.
		 */
		if (ino >= bctx->cur_objectid)
			return 0;
1179 1180 1181 1182
#if 0
		if (ino > bctx->cur_objectid)
			return 0;
		if (offset + bctx->extent_len > bctx->cur_offset)
1183
			return 0;
1184
#endif
1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203
	}

	bctx->found++;
	found->found_refs++;
	if (ino < found->ino) {
		found->ino = ino;
		found->offset = offset;
	} else if (found->ino == ino) {
		/*
		 * same extent found more then once in the same file.
		 */
		if (found->offset > offset + bctx->extent_len)
			found->offset = offset;
	}

	return 0;
}

/*
1204 1205 1206 1207 1208 1209
 * Given an inode, offset and extent item, it finds a good clone for a clone
 * instruction. Returns -ENOENT when none could be found. The function makes
 * sure that the returned clone is usable at the point where sending is at the
 * moment. This means, that no clones are accepted which lie behind the current
 * inode+offset.
 *
1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220
 * path must point to the extent item when called.
 */
static int find_extent_clone(struct send_ctx *sctx,
			     struct btrfs_path *path,
			     u64 ino, u64 data_offset,
			     u64 ino_size,
			     struct clone_root **found)
{
	int ret;
	int extent_type;
	u64 logical;
1221
	u64 disk_byte;
1222 1223
	u64 num_bytes;
	u64 extent_item_pos;
1224
	u64 flags = 0;
1225 1226
	struct btrfs_file_extent_item *fi;
	struct extent_buffer *eb = path->nodes[0];
1227
	struct backref_ctx *backref_ctx = NULL;
1228 1229 1230
	struct clone_root *cur_clone_root;
	struct btrfs_key found_key;
	struct btrfs_path *tmp_path;
1231
	int compressed;
1232 1233 1234 1235 1236 1237
	u32 i;

	tmp_path = alloc_path_for_send();
	if (!tmp_path)
		return -ENOMEM;

1238 1239 1240 1241 1242 1243
	backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
	if (!backref_ctx) {
		ret = -ENOMEM;
		goto out;
	}

1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260
	if (data_offset >= ino_size) {
		/*
		 * There may be extents that lie behind the file's size.
		 * I at least had this in combination with snapshotting while
		 * writing large files.
		 */
		ret = 0;
		goto out;
	}

	fi = btrfs_item_ptr(eb, path->slots[0],
			struct btrfs_file_extent_item);
	extent_type = btrfs_file_extent_type(eb, fi);
	if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
		ret = -ENOENT;
		goto out;
	}
1261
	compressed = btrfs_file_extent_compression(eb, fi);
1262 1263

	num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1264 1265
	disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
	if (disk_byte == 0) {
1266 1267 1268
		ret = -ENOENT;
		goto out;
	}
1269
	logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1270

1271 1272
	ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path,
				  &found_key, &flags);
1273 1274 1275 1276
	btrfs_release_path(tmp_path);

	if (ret < 0)
		goto out;
1277
	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291
		ret = -EIO;
		goto out;
	}

	/*
	 * Setup the clone roots.
	 */
	for (i = 0; i < sctx->clone_roots_cnt; i++) {
		cur_clone_root = sctx->clone_roots + i;
		cur_clone_root->ino = (u64)-1;
		cur_clone_root->offset = 0;
		cur_clone_root->found_refs = 0;
	}

1292 1293 1294 1295 1296 1297
	backref_ctx->sctx = sctx;
	backref_ctx->found = 0;
	backref_ctx->cur_objectid = ino;
	backref_ctx->cur_offset = data_offset;
	backref_ctx->found_itself = 0;
	backref_ctx->extent_len = num_bytes;
1298 1299 1300 1301 1302 1303 1304

	/*
	 * The last extent of a file may be too large due to page alignment.
	 * We need to adjust extent_len in this case so that the checks in
	 * __iterate_backrefs work.
	 */
	if (data_offset + num_bytes >= ino_size)
1305
		backref_ctx->extent_len = ino_size - data_offset;
1306 1307 1308 1309

	/*
	 * Now collect all backrefs.
	 */
1310 1311 1312 1313
	if (compressed == BTRFS_COMPRESS_NONE)
		extent_item_pos = logical - found_key.objectid;
	else
		extent_item_pos = 0;
1314 1315
	ret = iterate_extent_inodes(sctx->send_root->fs_info,
					found_key.objectid, extent_item_pos, 1,
1316
					__iterate_backrefs, backref_ctx);
1317

1318 1319 1320
	if (ret < 0)
		goto out;

1321
	if (!backref_ctx->found_itself) {
1322 1323
		/* found a bug in backref code? */
		ret = -EIO;
1324
		btrfs_err(sctx->send_root->fs_info, "did not find backref in "
1325
				"send_root. inode=%llu, offset=%llu, "
1326 1327
				"disk_byte=%llu found extent=%llu\n",
				ino, data_offset, disk_byte, found_key.objectid);
1328 1329 1330 1331 1332 1333 1334 1335
		goto out;
	}

verbose_printk(KERN_DEBUG "btrfs: find_extent_clone: data_offset=%llu, "
		"ino=%llu, "
		"num_bytes=%llu, logical=%llu\n",
		data_offset, ino, num_bytes, logical);

1336
	if (!backref_ctx->found)
1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351
		verbose_printk("btrfs:    no clones found\n");

	cur_clone_root = NULL;
	for (i = 0; i < sctx->clone_roots_cnt; i++) {
		if (sctx->clone_roots[i].found_refs) {
			if (!cur_clone_root)
				cur_clone_root = sctx->clone_roots + i;
			else if (sctx->clone_roots[i].root == sctx->send_root)
				/* prefer clones from send_root over others */
				cur_clone_root = sctx->clone_roots + i;
		}

	}

	if (cur_clone_root) {
1352 1353 1354 1355 1356 1357 1358 1359 1360 1361
		if (compressed != BTRFS_COMPRESS_NONE) {
			/*
			 * Offsets given by iterate_extent_inodes() are relative
			 * to the start of the extent, we need to add logical
			 * offset from the file extent item.
			 * (See why at backref.c:check_extent_in_eb())
			 */
			cur_clone_root->offset += btrfs_file_extent_offset(eb,
									   fi);
		}
1362 1363 1364 1365 1366 1367 1368 1369
		*found = cur_clone_root;
		ret = 0;
	} else {
		ret = -ENOENT;
	}

out:
	btrfs_free_path(tmp_path);
1370
	kfree(backref_ctx);
1371 1372 1373
	return ret;
}

1374
static int read_symlink(struct btrfs_root *root,
1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406
			u64 ino,
			struct fs_path *dest)
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_file_extent_item *ei;
	u8 type;
	u8 compression;
	unsigned long off;
	int len;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	key.objectid = ino;
	key.type = BTRFS_EXTENT_DATA_KEY;
	key.offset = 0;
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	BUG_ON(ret);

	ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
			struct btrfs_file_extent_item);
	type = btrfs_file_extent_type(path->nodes[0], ei);
	compression = btrfs_file_extent_compression(path->nodes[0], ei);
	BUG_ON(type != BTRFS_FILE_EXTENT_INLINE);
	BUG_ON(compression);

	off = btrfs_file_extent_inline_start(ei);
1407
	len = btrfs_file_extent_inline_len(path->nodes[0], path->slots[0], ei);
1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435

	ret = fs_path_add_from_extent_buffer(dest, path->nodes[0], off, len);

out:
	btrfs_free_path(path);
	return ret;
}

/*
 * Helper function to generate a file name that is unique in the root of
 * send_root and parent_root. This is used to generate names for orphan inodes.
 */
static int gen_unique_name(struct send_ctx *sctx,
			   u64 ino, u64 gen,
			   struct fs_path *dest)
{
	int ret = 0;
	struct btrfs_path *path;
	struct btrfs_dir_item *di;
	char tmp[64];
	int len;
	u64 idx = 0;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	while (1) {
1436
		len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
1437
				ino, gen, idx);
1438
		ASSERT(len < sizeof(tmp));
1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500

		di = btrfs_lookup_dir_item(NULL, sctx->send_root,
				path, BTRFS_FIRST_FREE_OBJECTID,
				tmp, strlen(tmp), 0);
		btrfs_release_path(path);
		if (IS_ERR(di)) {
			ret = PTR_ERR(di);
			goto out;
		}
		if (di) {
			/* not unique, try again */
			idx++;
			continue;
		}

		if (!sctx->parent_root) {
			/* unique */
			ret = 0;
			break;
		}

		di = btrfs_lookup_dir_item(NULL, sctx->parent_root,
				path, BTRFS_FIRST_FREE_OBJECTID,
				tmp, strlen(tmp), 0);
		btrfs_release_path(path);
		if (IS_ERR(di)) {
			ret = PTR_ERR(di);
			goto out;
		}
		if (di) {
			/* not unique, try again */
			idx++;
			continue;
		}
		/* unique */
		break;
	}

	ret = fs_path_add(dest, tmp, strlen(tmp));

out:
	btrfs_free_path(path);
	return ret;
}

enum inode_state {
	inode_state_no_change,
	inode_state_will_create,
	inode_state_did_create,
	inode_state_will_delete,
	inode_state_did_delete,
};

static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
{
	int ret;
	int left_ret;
	int right_ret;
	u64 left_gen;
	u64 right_gen;

	ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
1501
			NULL, NULL);
1502 1503 1504 1505 1506 1507 1508 1509
	if (ret < 0 && ret != -ENOENT)
		goto out;
	left_ret = ret;

	if (!sctx->parent_root) {
		right_ret = -ENOENT;
	} else {
		ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
1510
				NULL, NULL, NULL, NULL);
1511 1512 1513 1514 1515 1516
		if (ret < 0 && ret != -ENOENT)
			goto out;
		right_ret = ret;
	}

	if (!left_ret && !right_ret) {
1517
		if (left_gen == gen && right_gen == gen) {
1518
			ret = inode_state_no_change;
1519
		} else if (left_gen == gen) {
1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612
			if (ino < sctx->send_progress)
				ret = inode_state_did_create;
			else
				ret = inode_state_will_create;
		} else if (right_gen == gen) {
			if (ino < sctx->send_progress)
				ret = inode_state_did_delete;
			else
				ret = inode_state_will_delete;
		} else  {
			ret = -ENOENT;
		}
	} else if (!left_ret) {
		if (left_gen == gen) {
			if (ino < sctx->send_progress)
				ret = inode_state_did_create;
			else
				ret = inode_state_will_create;
		} else {
			ret = -ENOENT;
		}
	} else if (!right_ret) {
		if (right_gen == gen) {
			if (ino < sctx->send_progress)
				ret = inode_state_did_delete;
			else
				ret = inode_state_will_delete;
		} else {
			ret = -ENOENT;
		}
	} else {
		ret = -ENOENT;
	}

out:
	return ret;
}

static int is_inode_existent(struct send_ctx *sctx, u64 ino, u64 gen)
{
	int ret;

	ret = get_cur_inode_state(sctx, ino, gen);
	if (ret < 0)
		goto out;

	if (ret == inode_state_no_change ||
	    ret == inode_state_did_create ||
	    ret == inode_state_will_delete)
		ret = 1;
	else
		ret = 0;

out:
	return ret;
}

/*
 * Helper function to lookup a dir item in a dir.
 */
static int lookup_dir_item_inode(struct btrfs_root *root,
				 u64 dir, const char *name, int name_len,
				 u64 *found_inode,
				 u8 *found_type)
{
	int ret = 0;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
	struct btrfs_path *path;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	di = btrfs_lookup_dir_item(NULL, root, path,
			dir, name, name_len, 0);
	if (!di) {
		ret = -ENOENT;
		goto out;
	}
	if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto out;
	}
	btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
	*found_inode = key.objectid;
	*found_type = btrfs_dir_type(path->nodes[0], di);

out:
	btrfs_free_path(path);
	return ret;
}

1613 1614 1615 1616
/*
 * Looks up the first btrfs_inode_ref of a given ino. It returns the parent dir,
 * generation of the parent dir and the name of the dir entry.
 */
1617
static int get_first_ref(struct btrfs_root *root, u64 ino,
1618 1619 1620 1621 1622 1623 1624
			 u64 *dir, u64 *dir_gen, struct fs_path *name)
{
	int ret;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_path *path;
	int len;
1625
	u64 parent_dir;
1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	key.objectid = ino;
	key.type = BTRFS_INODE_REF_KEY;
	key.offset = 0;

	ret = btrfs_search_slot_for_read(root, &key, path, 1, 0);
	if (ret < 0)
		goto out;
	if (!ret)
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				path->slots[0]);
1641 1642 1643
	if (ret || found_key.objectid != ino ||
	    (found_key.type != BTRFS_INODE_REF_KEY &&
	     found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1644 1645 1646 1647
		ret = -ENOENT;
		goto out;
	}

1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665
	if (key.type == BTRFS_INODE_REF_KEY) {
		struct btrfs_inode_ref *iref;
		iref = btrfs_item_ptr(path->nodes[0], path->slots[0],
				      struct btrfs_inode_ref);
		len = btrfs_inode_ref_name_len(path->nodes[0], iref);
		ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
						     (unsigned long)(iref + 1),
						     len);
		parent_dir = found_key.offset;
	} else {
		struct btrfs_inode_extref *extref;
		extref = btrfs_item_ptr(path->nodes[0], path->slots[0],
					struct btrfs_inode_extref);
		len = btrfs_inode_extref_name_len(path->nodes[0], extref);
		ret = fs_path_add_from_extent_buffer(name, path->nodes[0],
					(unsigned long)&extref->name, len);
		parent_dir = btrfs_inode_extref_parent(path->nodes[0], extref);
	}
1666 1667 1668 1669
	if (ret < 0)
		goto out;
	btrfs_release_path(path);

1670
	ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
1671
			NULL, NULL);
1672 1673 1674
	if (ret < 0)
		goto out;

1675
	*dir = parent_dir;
1676 1677 1678 1679 1680 1681

out:
	btrfs_free_path(path);
	return ret;
}

1682
static int is_first_ref(struct btrfs_root *root,
1683 1684 1685 1686 1687 1688 1689 1690
			u64 ino, u64 dir,
			const char *name, int name_len)
{
	int ret;
	struct fs_path *tmp_name;
	u64 tmp_dir;
	u64 tmp_dir_gen;

1691
	tmp_name = fs_path_alloc();
1692 1693 1694
	if (!tmp_name)
		return -ENOMEM;

1695
	ret = get_first_ref(root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
1696 1697 1698
	if (ret < 0)
		goto out;

1699
	if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1700 1701 1702 1703
		ret = 0;
		goto out;
	}

1704
	ret = !memcmp(tmp_name->start, name, name_len);
1705 1706

out:
1707
	fs_path_free(tmp_name);
1708 1709 1710
	return ret;
}

1711 1712 1713 1714 1715 1716 1717 1718 1719 1720
/*
 * Used by process_recorded_refs to determine if a new ref would overwrite an
 * already existing ref. In case it detects an overwrite, it returns the
 * inode/gen in who_ino/who_gen.
 * When an overwrite is detected, process_recorded_refs does proper orphanizing
 * to make sure later references to the overwritten inode are possible.
 * Orphanizing is however only required for the first ref of an inode.
 * process_recorded_refs does an additional is_first_ref check to see if
 * orphanizing is really required.
 */
1721 1722 1723 1724 1725
static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
			      const char *name, int name_len,
			      u64 *who_ino, u64 *who_gen)
{
	int ret = 0;
1726
	u64 gen;
1727 1728 1729 1730 1731 1732 1733 1734 1735 1736
	u64 other_inode = 0;
	u8 other_type = 0;

	if (!sctx->parent_root)
		goto out;

	ret = is_inode_existent(sctx, dir, dir_gen);
	if (ret <= 0)
		goto out;

1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754
	/*
	 * If we have a parent root we need to verify that the parent dir was
	 * not delted and then re-created, if it was then we have no overwrite
	 * and we can just unlink this entry.
	 */
	if (sctx->parent_root) {
		ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
				     NULL, NULL, NULL);
		if (ret < 0 && ret != -ENOENT)
			goto out;
		if (ret) {
			ret = 0;
			goto out;
		}
		if (gen != dir_gen)
			goto out;
	}

1755 1756 1757 1758 1759 1760 1761 1762 1763
	ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len,
			&other_inode, &other_type);
	if (ret < 0 && ret != -ENOENT)
		goto out;
	if (ret) {
		ret = 0;
		goto out;
	}

1764 1765 1766 1767 1768
	/*
	 * Check if the overwritten ref was already processed. If yes, the ref
	 * was already unlinked/moved, so we can safely assume that we will not
	 * overwrite anything at this point in time.
	 */
1769 1770
	if (other_inode > sctx->send_progress) {
		ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1771
				who_gen, NULL, NULL, NULL, NULL);
1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784
		if (ret < 0)
			goto out;

		ret = 1;
		*who_ino = other_inode;
	} else {
		ret = 0;
	}

out:
	return ret;
}

1785 1786 1787 1788 1789 1790 1791
/*
 * Checks if the ref was overwritten by an already processed inode. This is
 * used by __get_cur_name_and_parent to find out if the ref was orphanized and
 * thus the orphan name needs be used.
 * process_recorded_refs also uses it to avoid unlinking of refs that were
 * overwritten.
 */
1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820
static int did_overwrite_ref(struct send_ctx *sctx,
			    u64 dir, u64 dir_gen,
			    u64 ino, u64 ino_gen,
			    const char *name, int name_len)
{
	int ret = 0;
	u64 gen;
	u64 ow_inode;
	u8 other_type;

	if (!sctx->parent_root)
		goto out;

	ret = is_inode_existent(sctx, dir, dir_gen);
	if (ret <= 0)
		goto out;

	/* check if the ref was overwritten by another ref */
	ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len,
			&ow_inode, &other_type);
	if (ret < 0 && ret != -ENOENT)
		goto out;
	if (ret) {
		/* was never and will never be overwritten */
		ret = 0;
		goto out;
	}

	ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
1821
			NULL, NULL);
1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839
	if (ret < 0)
		goto out;

	if (ow_inode == ino && gen == ino_gen) {
		ret = 0;
		goto out;
	}

	/* we know that it is or will be overwritten. check this now */
	if (ow_inode < sctx->send_progress)
		ret = 1;
	else
		ret = 0;

out:
	return ret;
}

1840 1841 1842 1843 1844
/*
 * Same as did_overwrite_ref, but also checks if it is the first ref of an inode
 * that got overwritten. This is used by process_recorded_refs to determine
 * if it has to use the path as returned by get_cur_path or the orphan name.
 */
1845 1846 1847 1848 1849 1850 1851 1852 1853 1854
static int did_overwrite_first_ref(struct send_ctx *sctx, u64 ino, u64 gen)
{
	int ret = 0;
	struct fs_path *name = NULL;
	u64 dir;
	u64 dir_gen;

	if (!sctx->parent_root)
		goto out;

1855
	name = fs_path_alloc();
1856 1857 1858
	if (!name)
		return -ENOMEM;

1859
	ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
1860 1861 1862 1863 1864 1865 1866
	if (ret < 0)
		goto out;

	ret = did_overwrite_ref(sctx, dir, dir_gen, ino, gen,
			name->start, fs_path_len(name));

out:
1867
	fs_path_free(name);
1868 1869 1870
	return ret;
}

1871 1872 1873 1874
/*
 * Insert a name cache entry. On 32bit kernels the radix tree index is 32bit,
 * so we need to do some special handling in case we have clashes. This function
 * takes care of this with the help of name_cache_entry::radix_list.
1875
 * In case of error, nce is kfreed.
1876
 */
1877 1878 1879 1880
static int name_cache_insert(struct send_ctx *sctx,
			     struct name_cache_entry *nce)
{
	int ret = 0;
1881 1882 1883 1884 1885 1886
	struct list_head *nce_head;

	nce_head = radix_tree_lookup(&sctx->name_cache,
			(unsigned long)nce->ino);
	if (!nce_head) {
		nce_head = kmalloc(sizeof(*nce_head), GFP_NOFS);
1887 1888
		if (!nce_head) {
			kfree(nce);
1889
			return -ENOMEM;
1890
		}
1891
		INIT_LIST_HEAD(nce_head);
1892

1893
		ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
1894 1895 1896
		if (ret < 0) {
			kfree(nce_head);
			kfree(nce);
1897
			return ret;
1898
		}
1899
	}
1900
	list_add_tail(&nce->radix_list, nce_head);
1901 1902 1903 1904 1905 1906 1907 1908 1909
	list_add_tail(&nce->list, &sctx->name_cache_list);
	sctx->name_cache_size++;

	return ret;
}

static void name_cache_delete(struct send_ctx *sctx,
			      struct name_cache_entry *nce)
{
1910
	struct list_head *nce_head;
1911

1912 1913
	nce_head = radix_tree_lookup(&sctx->name_cache,
			(unsigned long)nce->ino);
1914 1915 1916 1917 1918
	if (!nce_head) {
		btrfs_err(sctx->send_root->fs_info,
	      "name_cache_delete lookup failed ino %llu cache size %d, leaking memory",
			nce->ino, sctx->name_cache_size);
	}
1919

1920
	list_del(&nce->radix_list);
1921 1922
	list_del(&nce->list);
	sctx->name_cache_size--;
1923

1924 1925 1926 1927
	/*
	 * We may not get to the final release of nce_head if the lookup fails
	 */
	if (nce_head && list_empty(nce_head)) {
1928 1929 1930
		radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
		kfree(nce_head);
	}
1931 1932 1933 1934 1935
}

static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
						    u64 ino, u64 gen)
{
1936 1937
	struct list_head *nce_head;
	struct name_cache_entry *cur;
1938

1939 1940
	nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
	if (!nce_head)
1941 1942
		return NULL;

1943 1944 1945 1946
	list_for_each_entry(cur, nce_head, radix_list) {
		if (cur->ino == ino && cur->gen == gen)
			return cur;
	}
1947 1948 1949
	return NULL;
}

1950 1951 1952 1953
/*
 * Removes the entry from the list and adds it back to the end. This marks the
 * entry as recently used so that name_cache_clean_unused does not remove it.
 */
1954 1955 1956 1957 1958 1959
static void name_cache_used(struct send_ctx *sctx, struct name_cache_entry *nce)
{
	list_del(&nce->list);
	list_add_tail(&nce->list, &sctx->name_cache_list);
}

1960 1961 1962
/*
 * Remove some entries from the beginning of name_cache_list.
 */
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981
static void name_cache_clean_unused(struct send_ctx *sctx)
{
	struct name_cache_entry *nce;

	if (sctx->name_cache_size < SEND_CTX_NAME_CACHE_CLEAN_SIZE)
		return;

	while (sctx->name_cache_size > SEND_CTX_MAX_NAME_CACHE_SIZE) {
		nce = list_entry(sctx->name_cache_list.next,
				struct name_cache_entry, list);
		name_cache_delete(sctx, nce);
		kfree(nce);
	}
}

static void name_cache_free(struct send_ctx *sctx)
{
	struct name_cache_entry *nce;

1982 1983 1984
	while (!list_empty(&sctx->name_cache_list)) {
		nce = list_entry(sctx->name_cache_list.next,
				struct name_cache_entry, list);
1985
		name_cache_delete(sctx, nce);
1986
		kfree(nce);
1987 1988 1989
	}
}

1990 1991 1992 1993 1994 1995 1996 1997
/*
 * Used by get_cur_path for each ref up to the root.
 * Returns 0 if it succeeded.
 * Returns 1 if the inode is not existent or got overwritten. In that case, the
 * name is an orphan name. This instructs get_cur_path to stop iterating. If 1
 * is returned, parent_ino/parent_gen are not guaranteed to be valid.
 * Returns <0 in case of error.
 */
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
static int __get_cur_name_and_parent(struct send_ctx *sctx,
				     u64 ino, u64 gen,
				     u64 *parent_ino,
				     u64 *parent_gen,
				     struct fs_path *dest)
{
	int ret;
	int nce_ret;
	struct btrfs_path *path = NULL;
	struct name_cache_entry *nce = NULL;

2009 2010 2011 2012 2013
	/*
	 * First check if we already did a call to this function with the same
	 * ino/gen. If yes, check if the cache entry is still up-to-date. If yes
	 * return the cached result.
	 */
2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
	nce = name_cache_search(sctx, ino, gen);
	if (nce) {
		if (ino < sctx->send_progress && nce->need_later_update) {
			name_cache_delete(sctx, nce);
			kfree(nce);
			nce = NULL;
		} else {
			name_cache_used(sctx, nce);
			*parent_ino = nce->parent_ino;
			*parent_gen = nce->parent_gen;
			ret = fs_path_add(dest, nce->name, nce->name_len);
			if (ret < 0)
				goto out;
			ret = nce->ret;
			goto out;
		}
	}

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

2036 2037 2038 2039 2040
	/*
	 * If the inode is not existent yet, add the orphan name and return 1.
	 * This should only happen for the parent dir that we determine in
	 * __record_new_ref
	 */
2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052
	ret = is_inode_existent(sctx, ino, gen);
	if (ret < 0)
		goto out;

	if (!ret) {
		ret = gen_unique_name(sctx, ino, gen, dest);
		if (ret < 0)
			goto out;
		ret = 1;
		goto out_cache;
	}

2053 2054 2055 2056
	/*
	 * Depending on whether the inode was already processed or not, use
	 * send_root or parent_root for ref lookup.
	 */
2057
	if (ino < sctx->send_progress)
2058 2059
		ret = get_first_ref(sctx->send_root, ino,
				    parent_ino, parent_gen, dest);
2060
	else
2061 2062
		ret = get_first_ref(sctx->parent_root, ino,
				    parent_ino, parent_gen, dest);
2063 2064 2065
	if (ret < 0)
		goto out;

2066 2067 2068 2069
	/*
	 * Check if the ref was overwritten by an inode's ref that was processed
	 * earlier. If yes, treat as orphan and return 1.
	 */
2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082
	ret = did_overwrite_ref(sctx, *parent_ino, *parent_gen, ino, gen,
			dest->start, dest->end - dest->start);
	if (ret < 0)
		goto out;
	if (ret) {
		fs_path_reset(dest);
		ret = gen_unique_name(sctx, ino, gen, dest);
		if (ret < 0)
			goto out;
		ret = 1;
	}

out_cache:
2083 2084 2085
	/*
	 * Store the result of the lookup in the name cache.
	 */
2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148
	nce = kmalloc(sizeof(*nce) + fs_path_len(dest) + 1, GFP_NOFS);
	if (!nce) {
		ret = -ENOMEM;
		goto out;
	}

	nce->ino = ino;
	nce->gen = gen;
	nce->parent_ino = *parent_ino;
	nce->parent_gen = *parent_gen;
	nce->name_len = fs_path_len(dest);
	nce->ret = ret;
	strcpy(nce->name, dest->start);

	if (ino < sctx->send_progress)
		nce->need_later_update = 0;
	else
		nce->need_later_update = 1;

	nce_ret = name_cache_insert(sctx, nce);
	if (nce_ret < 0)
		ret = nce_ret;
	name_cache_clean_unused(sctx);

out:
	btrfs_free_path(path);
	return ret;
}

/*
 * Magic happens here. This function returns the first ref to an inode as it
 * would look like while receiving the stream at this point in time.
 * We walk the path up to the root. For every inode in between, we check if it
 * was already processed/sent. If yes, we continue with the parent as found
 * in send_root. If not, we continue with the parent as found in parent_root.
 * If we encounter an inode that was deleted at this point in time, we use the
 * inodes "orphan" name instead of the real name and stop. Same with new inodes
 * that were not created yet and overwritten inodes/refs.
 *
 * When do we have have orphan inodes:
 * 1. When an inode is freshly created and thus no valid refs are available yet
 * 2. When a directory lost all it's refs (deleted) but still has dir items
 *    inside which were not processed yet (pending for move/delete). If anyone
 *    tried to get the path to the dir items, it would get a path inside that
 *    orphan directory.
 * 3. When an inode is moved around or gets new links, it may overwrite the ref
 *    of an unprocessed inode. If in that case the first ref would be
 *    overwritten, the overwritten inode gets "orphanized". Later when we
 *    process this overwritten inode, it is restored at a new place by moving
 *    the orphan inode.
 *
 * sctx->send_progress tells this function at which point in time receiving
 * would be.
 */
static int get_cur_path(struct send_ctx *sctx, u64 ino, u64 gen,
			struct fs_path *dest)
{
	int ret = 0;
	struct fs_path *name = NULL;
	u64 parent_inode = 0;
	u64 parent_gen = 0;
	int stop = 0;

2149
	name = fs_path_alloc();
2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160
	if (!name) {
		ret = -ENOMEM;
		goto out;
	}

	dest->reversed = 1;
	fs_path_reset(dest);

	while (!stop && ino != BTRFS_FIRST_FREE_OBJECTID) {
		fs_path_reset(name);

2161 2162 2163 2164 2165 2166 2167 2168
		if (is_waiting_for_rm(sctx, ino)) {
			ret = gen_unique_name(sctx, ino, gen, name);
			if (ret < 0)
				goto out;
			ret = fs_path_add_path(dest, name);
			break;
		}

2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179
		if (is_waiting_for_move(sctx, ino)) {
			ret = get_first_ref(sctx->parent_root, ino,
					    &parent_inode, &parent_gen, name);
		} else {
			ret = __get_cur_name_and_parent(sctx, ino, gen,
							&parent_inode,
							&parent_gen, name);
			if (ret)
				stop = 1;
		}

2180 2181
		if (ret < 0)
			goto out;
2182

2183 2184 2185 2186 2187 2188 2189 2190 2191
		ret = fs_path_add_path(dest, name);
		if (ret < 0)
			goto out;

		ino = parent_inode;
		gen = parent_gen;
	}

out:
2192
	fs_path_free(name);
2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212
	if (!ret)
		fs_path_unreverse(dest);
	return ret;
}

/*
 * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace
 */
static int send_subvol_begin(struct send_ctx *sctx)
{
	int ret;
	struct btrfs_root *send_root = sctx->send_root;
	struct btrfs_root *parent_root = sctx->parent_root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_root_ref *ref;
	struct extent_buffer *leaf;
	char *name = NULL;
	int namelen;

2213
	path = btrfs_alloc_path();
2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261
	if (!path)
		return -ENOMEM;

	name = kmalloc(BTRFS_PATH_NAME_MAX, GFP_NOFS);
	if (!name) {
		btrfs_free_path(path);
		return -ENOMEM;
	}

	key.objectid = send_root->objectid;
	key.type = BTRFS_ROOT_BACKREF_KEY;
	key.offset = 0;

	ret = btrfs_search_slot_for_read(send_root->fs_info->tree_root,
				&key, path, 1, 0);
	if (ret < 0)
		goto out;
	if (ret) {
		ret = -ENOENT;
		goto out;
	}

	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
	if (key.type != BTRFS_ROOT_BACKREF_KEY ||
	    key.objectid != send_root->objectid) {
		ret = -ENOENT;
		goto out;
	}
	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
	namelen = btrfs_root_ref_name_len(leaf, ref);
	read_extent_buffer(leaf, name, (unsigned long)(ref + 1), namelen);
	btrfs_release_path(path);

	if (parent_root) {
		ret = begin_cmd(sctx, BTRFS_SEND_C_SNAPSHOT);
		if (ret < 0)
			goto out;
	} else {
		ret = begin_cmd(sctx, BTRFS_SEND_C_SUBVOL);
		if (ret < 0)
			goto out;
	}

	TLV_PUT_STRING(sctx, BTRFS_SEND_A_PATH, name, namelen);
	TLV_PUT_UUID(sctx, BTRFS_SEND_A_UUID,
			sctx->send_root->root_item.uuid);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_CTRANSID,
2262
		    le64_to_cpu(sctx->send_root->root_item.ctransid));
2263 2264 2265 2266
	if (parent_root) {
		TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
				sctx->parent_root->root_item.uuid);
		TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
2267
			    le64_to_cpu(sctx->parent_root->root_item.ctransid));
2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285
	}

	ret = send_cmd(sctx);

tlv_put_failure:
out:
	btrfs_free_path(path);
	kfree(name);
	return ret;
}

static int send_truncate(struct send_ctx *sctx, u64 ino, u64 gen, u64 size)
{
	int ret = 0;
	struct fs_path *p;

verbose_printk("btrfs: send_truncate %llu size=%llu\n", ino, size);

2286
	p = fs_path_alloc();
2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303
	if (!p)
		return -ENOMEM;

	ret = begin_cmd(sctx, BTRFS_SEND_C_TRUNCATE);
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, ino, gen, p);
	if (ret < 0)
		goto out;
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, size);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
2304
	fs_path_free(p);
2305 2306 2307 2308 2309 2310 2311 2312 2313 2314
	return ret;
}

static int send_chmod(struct send_ctx *sctx, u64 ino, u64 gen, u64 mode)
{
	int ret = 0;
	struct fs_path *p;

verbose_printk("btrfs: send_chmod %llu mode=%llu\n", ino, mode);

2315
	p = fs_path_alloc();
2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332
	if (!p)
		return -ENOMEM;

	ret = begin_cmd(sctx, BTRFS_SEND_C_CHMOD);
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, ino, gen, p);
	if (ret < 0)
		goto out;
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode & 07777);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
2333
	fs_path_free(p);
2334 2335 2336 2337 2338 2339 2340 2341 2342 2343
	return ret;
}

static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
{
	int ret = 0;
	struct fs_path *p;

verbose_printk("btrfs: send_chown %llu uid=%llu, gid=%llu\n", ino, uid, gid);

2344
	p = fs_path_alloc();
2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362
	if (!p)
		return -ENOMEM;

	ret = begin_cmd(sctx, BTRFS_SEND_C_CHOWN);
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, ino, gen, p);
	if (ret < 0)
		goto out;
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_UID, uid);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_GID, gid);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
2363
	fs_path_free(p);
2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378
	return ret;
}

static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
{
	int ret = 0;
	struct fs_path *p = NULL;
	struct btrfs_inode_item *ii;
	struct btrfs_path *path = NULL;
	struct extent_buffer *eb;
	struct btrfs_key key;
	int slot;

verbose_printk("btrfs: send_utimes %llu\n", ino);

2379
	p = fs_path_alloc();
2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413
	if (!p)
		return -ENOMEM;

	path = alloc_path_for_send();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	key.objectid = ino;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;
	ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
	if (ret < 0)
		goto out;

	eb = path->nodes[0];
	slot = path->slots[0];
	ii = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);

	ret = begin_cmd(sctx, BTRFS_SEND_C_UTIMES);
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, ino, gen, p);
	if (ret < 0)
		goto out;
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
	TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_ATIME, eb,
			btrfs_inode_atime(ii));
	TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_MTIME, eb,
			btrfs_inode_mtime(ii));
	TLV_PUT_BTRFS_TIMESPEC(sctx, BTRFS_SEND_A_CTIME, eb,
			btrfs_inode_ctime(ii));
2414
	/* TODO Add otime support when the otime patches get into upstream */
2415 2416 2417 2418 2419

	ret = send_cmd(sctx);

tlv_put_failure:
out:
2420
	fs_path_free(p);
2421 2422 2423 2424 2425 2426 2427 2428 2429
	btrfs_free_path(path);
	return ret;
}

/*
 * Sends a BTRFS_SEND_C_MKXXX or SYMLINK command to user space. We don't have
 * a valid path yet because we did not process the refs yet. So, the inode
 * is created as orphan.
 */
2430
static int send_create_inode(struct send_ctx *sctx, u64 ino)
2431 2432 2433 2434
{
	int ret = 0;
	struct fs_path *p;
	int cmd;
2435
	u64 gen;
2436
	u64 mode;
2437
	u64 rdev;
2438

2439
verbose_printk("btrfs: send_create_inode %llu\n", ino);
2440

2441
	p = fs_path_alloc();
2442 2443 2444
	if (!p)
		return -ENOMEM;

L
Liu Bo 已提交
2445 2446 2447 2448 2449 2450 2451 2452 2453 2454
	if (ino != sctx->cur_ino) {
		ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode,
				     NULL, NULL, &rdev);
		if (ret < 0)
			goto out;
	} else {
		gen = sctx->cur_inode_gen;
		mode = sctx->cur_inode_mode;
		rdev = sctx->cur_inode_rdev;
	}
2455

2456
	if (S_ISREG(mode)) {
2457
		cmd = BTRFS_SEND_C_MKFILE;
2458
	} else if (S_ISDIR(mode)) {
2459
		cmd = BTRFS_SEND_C_MKDIR;
2460
	} else if (S_ISLNK(mode)) {
2461
		cmd = BTRFS_SEND_C_SYMLINK;
2462
	} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2463
		cmd = BTRFS_SEND_C_MKNOD;
2464
	} else if (S_ISFIFO(mode)) {
2465
		cmd = BTRFS_SEND_C_MKFIFO;
2466
	} else if (S_ISSOCK(mode)) {
2467
		cmd = BTRFS_SEND_C_MKSOCK;
2468
	} else {
2469 2470 2471 2472 2473 2474 2475 2476 2477 2478
		printk(KERN_WARNING "btrfs: unexpected inode type %o",
				(int)(mode & S_IFMT));
		ret = -ENOTSUPP;
		goto out;
	}

	ret = begin_cmd(sctx, cmd);
	if (ret < 0)
		goto out;

2479
	ret = gen_unique_name(sctx, ino, gen, p);
2480 2481 2482 2483
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2484
	TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2485 2486 2487

	if (S_ISLNK(mode)) {
		fs_path_reset(p);
2488
		ret = read_symlink(sctx->send_root, ino, p);
2489 2490 2491 2492 2493
		if (ret < 0)
			goto out;
		TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH_LINK, p);
	} else if (S_ISCHR(mode) || S_ISBLK(mode) ||
		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
2494 2495
		TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
		TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2496 2497 2498 2499 2500 2501 2502 2503 2504
	}

	ret = send_cmd(sctx);
	if (ret < 0)
		goto out;


tlv_put_failure:
out:
2505
	fs_path_free(p);
2506 2507 2508
	return ret;
}

2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533
/*
 * We need some special handling for inodes that get processed before the parent
 * directory got created. See process_recorded_refs for details.
 * This function does the check if we already created the dir out of order.
 */
static int did_create_dir(struct send_ctx *sctx, u64 dir)
{
	int ret = 0;
	struct btrfs_path *path = NULL;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_key di_key;
	struct extent_buffer *eb;
	struct btrfs_dir_item *di;
	int slot;

	path = alloc_path_for_send();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	key.objectid = dir;
	key.type = BTRFS_DIR_INDEX_KEY;
	key.offset = 0;
2534 2535 2536 2537
	ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
	if (ret < 0)
		goto out;

2538
	while (1) {
2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549
		eb = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(eb)) {
			ret = btrfs_next_leaf(sctx->send_root, path);
			if (ret < 0) {
				goto out;
			} else if (ret > 0) {
				ret = 0;
				break;
			}
			continue;
2550
		}
2551 2552 2553

		btrfs_item_key_to_cpu(eb, &found_key, slot);
		if (found_key.objectid != key.objectid ||
2554 2555 2556 2557 2558 2559 2560 2561
		    found_key.type != key.type) {
			ret = 0;
			goto out;
		}

		di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
		btrfs_dir_item_key_to_cpu(eb, di, &di_key);

2562 2563
		if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
		    di_key.objectid < sctx->send_progress) {
2564 2565 2566 2567
			ret = 1;
			goto out;
		}

2568
		path->slots[0]++;
2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603
	}

out:
	btrfs_free_path(path);
	return ret;
}

/*
 * Only creates the inode if it is:
 * 1. Not a directory
 * 2. Or a directory which was not created already due to out of order
 *    directories. See did_create_dir and process_recorded_refs for details.
 */
static int send_create_inode_if_needed(struct send_ctx *sctx)
{
	int ret;

	if (S_ISDIR(sctx->cur_inode_mode)) {
		ret = did_create_dir(sctx, sctx->cur_ino);
		if (ret < 0)
			goto out;
		if (ret) {
			ret = 0;
			goto out;
		}
	}

	ret = send_create_inode(sctx, sctx->cur_ino);
	if (ret < 0)
		goto out;

out:
	return ret;
}

2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619
struct recorded_ref {
	struct list_head list;
	char *dir_path;
	char *name;
	struct fs_path *full_path;
	u64 dir;
	u64 dir_gen;
	int dir_path_len;
	int name_len;
};

/*
 * We need to process new refs before deleted refs, but compare_tree gives us
 * everything mixed. So we first record all refs and later process them.
 * This function is a helper to record one ref.
 */
2620
static int __record_ref(struct list_head *head, u64 dir,
2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
		      u64 dir_gen, struct fs_path *path)
{
	struct recorded_ref *ref;

	ref = kmalloc(sizeof(*ref), GFP_NOFS);
	if (!ref)
		return -ENOMEM;

	ref->dir = dir;
	ref->dir_gen = dir_gen;
	ref->full_path = path;

A
Andy Shevchenko 已提交
2633 2634 2635 2636
	ref->name = (char *)kbasename(ref->full_path->start);
	ref->name_len = ref->full_path->end - ref->name;
	ref->dir_path = ref->full_path->start;
	if (ref->name == ref->full_path->start)
2637
		ref->dir_path_len = 0;
A
Andy Shevchenko 已提交
2638
	else
2639 2640 2641 2642 2643 2644 2645
		ref->dir_path_len = ref->full_path->end -
				ref->full_path->start - 1 - ref->name_len;

	list_add_tail(&ref->list, head);
	return 0;
}

2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661
static int dup_ref(struct recorded_ref *ref, struct list_head *list)
{
	struct recorded_ref *new;

	new = kmalloc(sizeof(*ref), GFP_NOFS);
	if (!new)
		return -ENOMEM;

	new->dir = ref->dir;
	new->dir_gen = ref->dir_gen;
	new->full_path = NULL;
	INIT_LIST_HEAD(&new->list);
	list_add_tail(&new->list, list);
	return 0;
}

2662
static void __free_recorded_refs(struct list_head *head)
2663 2664 2665
{
	struct recorded_ref *cur;

2666 2667
	while (!list_empty(head)) {
		cur = list_entry(head->next, struct recorded_ref, list);
2668
		fs_path_free(cur->full_path);
2669
		list_del(&cur->list);
2670 2671 2672 2673 2674 2675
		kfree(cur);
	}
}

static void free_recorded_refs(struct send_ctx *sctx)
{
2676 2677
	__free_recorded_refs(&sctx->new_refs);
	__free_recorded_refs(&sctx->deleted_refs);
2678 2679 2680
}

/*
2681
 * Renames/moves a file/dir to its orphan name. Used when the first
2682 2683 2684 2685 2686 2687 2688 2689 2690
 * ref of an unprocessed inode gets overwritten and for all non empty
 * directories.
 */
static int orphanize_inode(struct send_ctx *sctx, u64 ino, u64 gen,
			  struct fs_path *path)
{
	int ret;
	struct fs_path *orphan;

2691
	orphan = fs_path_alloc();
2692 2693 2694 2695 2696 2697 2698 2699 2700 2701
	if (!orphan)
		return -ENOMEM;

	ret = gen_unique_name(sctx, ino, gen, orphan);
	if (ret < 0)
		goto out;

	ret = send_rename(sctx, path, orphan);

out:
2702
	fs_path_free(orphan);
2703 2704 2705
	return ret;
}

2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770
static struct orphan_dir_info *
add_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
{
	struct rb_node **p = &sctx->orphan_dirs.rb_node;
	struct rb_node *parent = NULL;
	struct orphan_dir_info *entry, *odi;

	odi = kmalloc(sizeof(*odi), GFP_NOFS);
	if (!odi)
		return ERR_PTR(-ENOMEM);
	odi->ino = dir_ino;
	odi->gen = 0;

	while (*p) {
		parent = *p;
		entry = rb_entry(parent, struct orphan_dir_info, node);
		if (dir_ino < entry->ino) {
			p = &(*p)->rb_left;
		} else if (dir_ino > entry->ino) {
			p = &(*p)->rb_right;
		} else {
			kfree(odi);
			return entry;
		}
	}

	rb_link_node(&odi->node, parent, p);
	rb_insert_color(&odi->node, &sctx->orphan_dirs);
	return odi;
}

static struct orphan_dir_info *
get_orphan_dir_info(struct send_ctx *sctx, u64 dir_ino)
{
	struct rb_node *n = sctx->orphan_dirs.rb_node;
	struct orphan_dir_info *entry;

	while (n) {
		entry = rb_entry(n, struct orphan_dir_info, node);
		if (dir_ino < entry->ino)
			n = n->rb_left;
		else if (dir_ino > entry->ino)
			n = n->rb_right;
		else
			return entry;
	}
	return NULL;
}

static int is_waiting_for_rm(struct send_ctx *sctx, u64 dir_ino)
{
	struct orphan_dir_info *odi = get_orphan_dir_info(sctx, dir_ino);

	return odi != NULL;
}

static void free_orphan_dir_info(struct send_ctx *sctx,
				 struct orphan_dir_info *odi)
{
	if (!odi)
		return;
	rb_erase(&odi->node, &sctx->orphan_dirs);
	kfree(odi);
}

2771 2772 2773 2774 2775
/*
 * Returns 1 if a directory can be removed at this point in time.
 * We check this by iterating all dir items and checking if the inode behind
 * the dir item was already processed.
 */
2776 2777
static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
		     u64 send_progress)
2778 2779 2780 2781 2782 2783 2784 2785 2786
{
	int ret = 0;
	struct btrfs_root *root = sctx->parent_root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_key loc;
	struct btrfs_dir_item *di;

2787 2788 2789 2790 2791 2792
	/*
	 * Don't try to rmdir the top/root subvolume dir.
	 */
	if (dir == BTRFS_FIRST_FREE_OBJECTID)
		return 0;

2793 2794 2795 2796 2797 2798 2799
	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	key.objectid = dir;
	key.type = BTRFS_DIR_INDEX_KEY;
	key.offset = 0;
2800 2801 2802
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
2803 2804

	while (1) {
2805 2806
		struct waiting_dir_move *dm;

2807 2808 2809 2810 2811 2812 2813
		if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				goto out;
			else if (ret > 0)
				break;
			continue;
2814
		}
2815 2816 2817 2818
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);
		if (found_key.objectid != key.objectid ||
		    found_key.type != key.type)
2819 2820 2821 2822 2823 2824
			break;

		di = btrfs_item_ptr(path->nodes[0], path->slots[0],
				struct btrfs_dir_item);
		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &loc);

2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839
		dm = get_waiting_dir_move(sctx, loc.objectid);
		if (dm) {
			struct orphan_dir_info *odi;

			odi = add_orphan_dir_info(sctx, dir);
			if (IS_ERR(odi)) {
				ret = PTR_ERR(odi);
				goto out;
			}
			odi->gen = dir_gen;
			dm->rmdir_ino = dir;
			ret = 0;
			goto out;
		}

2840 2841 2842 2843 2844
		if (loc.objectid > send_progress) {
			ret = 0;
			goto out;
		}

2845
		path->slots[0]++;
2846 2847 2848 2849 2850 2851 2852 2853 2854
	}

	ret = 1;

out:
	btrfs_free_path(path);
	return ret;
}

2855 2856
static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
{
2857
	struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino);
2858

2859
	return entry != NULL;
2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871
}

static int add_waiting_dir_move(struct send_ctx *sctx, u64 ino)
{
	struct rb_node **p = &sctx->waiting_dir_moves.rb_node;
	struct rb_node *parent = NULL;
	struct waiting_dir_move *entry, *dm;

	dm = kmalloc(sizeof(*dm), GFP_NOFS);
	if (!dm)
		return -ENOMEM;
	dm->ino = ino;
2872
	dm->rmdir_ino = 0;
2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891

	while (*p) {
		parent = *p;
		entry = rb_entry(parent, struct waiting_dir_move, node);
		if (ino < entry->ino) {
			p = &(*p)->rb_left;
		} else if (ino > entry->ino) {
			p = &(*p)->rb_right;
		} else {
			kfree(dm);
			return -EEXIST;
		}
	}

	rb_link_node(&dm->node, parent, p);
	rb_insert_color(&dm->node, &sctx->waiting_dir_moves);
	return 0;
}

2892 2893
static struct waiting_dir_move *
get_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2894 2895 2896 2897 2898 2899
{
	struct rb_node *n = sctx->waiting_dir_moves.rb_node;
	struct waiting_dir_move *entry;

	while (n) {
		entry = rb_entry(n, struct waiting_dir_move, node);
2900
		if (ino < entry->ino)
2901
			n = n->rb_left;
2902
		else if (ino > entry->ino)
2903
			n = n->rb_right;
2904 2905
		else
			return entry;
2906
	}
2907 2908 2909 2910 2911 2912 2913 2914 2915 2916
	return NULL;
}

static void free_waiting_dir_move(struct send_ctx *sctx,
				  struct waiting_dir_move *dm)
{
	if (!dm)
		return;
	rb_erase(&dm->node, &sctx->waiting_dir_moves);
	kfree(dm);
2917 2918
}

2919 2920 2921 2922
static int add_pending_dir_move(struct send_ctx *sctx,
				u64 ino,
				u64 ino_gen,
				u64 parent_ino)
2923 2924 2925
{
	struct rb_node **p = &sctx->pending_dir_moves.rb_node;
	struct rb_node *parent = NULL;
C
Chris Mason 已提交
2926
	struct pending_dir_move *entry = NULL, *pm;
2927 2928 2929 2930 2931 2932 2933 2934
	struct recorded_ref *cur;
	int exists = 0;
	int ret;

	pm = kmalloc(sizeof(*pm), GFP_NOFS);
	if (!pm)
		return -ENOMEM;
	pm->parent_ino = parent_ino;
2935 2936
	pm->ino = ino;
	pm->gen = ino_gen;
2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005
	INIT_LIST_HEAD(&pm->list);
	INIT_LIST_HEAD(&pm->update_refs);
	RB_CLEAR_NODE(&pm->node);

	while (*p) {
		parent = *p;
		entry = rb_entry(parent, struct pending_dir_move, node);
		if (parent_ino < entry->parent_ino) {
			p = &(*p)->rb_left;
		} else if (parent_ino > entry->parent_ino) {
			p = &(*p)->rb_right;
		} else {
			exists = 1;
			break;
		}
	}

	list_for_each_entry(cur, &sctx->deleted_refs, list) {
		ret = dup_ref(cur, &pm->update_refs);
		if (ret < 0)
			goto out;
	}
	list_for_each_entry(cur, &sctx->new_refs, list) {
		ret = dup_ref(cur, &pm->update_refs);
		if (ret < 0)
			goto out;
	}

	ret = add_waiting_dir_move(sctx, pm->ino);
	if (ret)
		goto out;

	if (exists) {
		list_add_tail(&pm->list, &entry->list);
	} else {
		rb_link_node(&pm->node, parent, p);
		rb_insert_color(&pm->node, &sctx->pending_dir_moves);
	}
	ret = 0;
out:
	if (ret) {
		__free_recorded_refs(&pm->update_refs);
		kfree(pm);
	}
	return ret;
}

static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
						      u64 parent_ino)
{
	struct rb_node *n = sctx->pending_dir_moves.rb_node;
	struct pending_dir_move *entry;

	while (n) {
		entry = rb_entry(n, struct pending_dir_move, node);
		if (parent_ino < entry->parent_ino)
			n = n->rb_left;
		else if (parent_ino > entry->parent_ino)
			n = n->rb_right;
		else
			return entry;
	}
	return NULL;
}

static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
{
	struct fs_path *from_path = NULL;
	struct fs_path *to_path = NULL;
3006
	struct fs_path *name = NULL;
3007 3008
	u64 orig_progress = sctx->send_progress;
	struct recorded_ref *cur;
3009
	u64 parent_ino, parent_gen;
3010 3011
	struct waiting_dir_move *dm = NULL;
	u64 rmdir_ino = 0;
3012 3013
	int ret;

3014
	name = fs_path_alloc();
3015
	from_path = fs_path_alloc();
3016 3017 3018 3019
	if (!name || !from_path) {
		ret = -ENOMEM;
		goto out;
	}
3020

3021 3022 3023 3024
	dm = get_waiting_dir_move(sctx, pm->ino);
	ASSERT(dm);
	rmdir_ino = dm->rmdir_ino;
	free_waiting_dir_move(sctx, dm);
3025 3026 3027

	ret = get_first_ref(sctx->parent_root, pm->ino,
			    &parent_ino, &parent_gen, name);
3028 3029 3030
	if (ret < 0)
		goto out;

3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051
	if (parent_ino == sctx->cur_ino) {
		/* child only renamed, not moved */
		ASSERT(parent_gen == sctx->cur_inode_gen);
		ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
				   from_path);
		if (ret < 0)
			goto out;
		ret = fs_path_add_path(from_path, name);
		if (ret < 0)
			goto out;
	} else {
		/* child moved and maybe renamed too */
		sctx->send_progress = pm->ino;
		ret = get_cur_path(sctx, pm->ino, pm->gen, from_path);
		if (ret < 0)
			goto out;
	}

	fs_path_free(name);
	name = NULL;

3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066
	to_path = fs_path_alloc();
	if (!to_path) {
		ret = -ENOMEM;
		goto out;
	}

	sctx->send_progress = sctx->cur_ino + 1;
	ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
	if (ret < 0)
		goto out;

	ret = send_rename(sctx, from_path, to_path);
	if (ret < 0)
		goto out;

3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095
	if (rmdir_ino) {
		struct orphan_dir_info *odi;

		odi = get_orphan_dir_info(sctx, rmdir_ino);
		if (!odi) {
			/* already deleted */
			goto finish;
		}
		ret = can_rmdir(sctx, rmdir_ino, odi->gen, sctx->cur_ino + 1);
		if (ret < 0)
			goto out;
		if (!ret)
			goto finish;

		name = fs_path_alloc();
		if (!name) {
			ret = -ENOMEM;
			goto out;
		}
		ret = get_cur_path(sctx, rmdir_ino, odi->gen, name);
		if (ret < 0)
			goto out;
		ret = send_rmdir(sctx, name);
		if (ret < 0)
			goto out;
		free_orphan_dir_info(sctx, odi);
	}

finish:
3096 3097 3098 3099 3100 3101 3102 3103 3104
	ret = send_utimes(sctx, pm->ino, pm->gen);
	if (ret < 0)
		goto out;

	/*
	 * After rename/move, need to update the utimes of both new parent(s)
	 * and old parent(s).
	 */
	list_for_each_entry(cur, &pm->update_refs, list) {
3105 3106
		if (cur->dir == rmdir_ino)
			continue;
3107 3108 3109 3110 3111 3112
		ret = send_utimes(sctx, cur->dir, cur->dir_gen);
		if (ret < 0)
			goto out;
	}

out:
3113
	fs_path_free(name);
3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184
	fs_path_free(from_path);
	fs_path_free(to_path);
	sctx->send_progress = orig_progress;

	return ret;
}

static void free_pending_move(struct send_ctx *sctx, struct pending_dir_move *m)
{
	if (!list_empty(&m->list))
		list_del(&m->list);
	if (!RB_EMPTY_NODE(&m->node))
		rb_erase(&m->node, &sctx->pending_dir_moves);
	__free_recorded_refs(&m->update_refs);
	kfree(m);
}

static void tail_append_pending_moves(struct pending_dir_move *moves,
				      struct list_head *stack)
{
	if (list_empty(&moves->list)) {
		list_add_tail(&moves->list, stack);
	} else {
		LIST_HEAD(list);
		list_splice_init(&moves->list, &list);
		list_add_tail(&moves->list, stack);
		list_splice_tail(&list, stack);
	}
}

static int apply_children_dir_moves(struct send_ctx *sctx)
{
	struct pending_dir_move *pm;
	struct list_head stack;
	u64 parent_ino = sctx->cur_ino;
	int ret = 0;

	pm = get_pending_dir_moves(sctx, parent_ino);
	if (!pm)
		return 0;

	INIT_LIST_HEAD(&stack);
	tail_append_pending_moves(pm, &stack);

	while (!list_empty(&stack)) {
		pm = list_first_entry(&stack, struct pending_dir_move, list);
		parent_ino = pm->ino;
		ret = apply_dir_move(sctx, pm);
		free_pending_move(sctx, pm);
		if (ret)
			goto out;
		pm = get_pending_dir_moves(sctx, parent_ino);
		if (pm)
			tail_append_pending_moves(pm, &stack);
	}
	return 0;

out:
	while (!list_empty(&stack)) {
		pm = list_first_entry(&stack, struct pending_dir_move, list);
		free_pending_move(sctx, pm);
	}
	return ret;
}

static int wait_for_parent_move(struct send_ctx *sctx,
				struct recorded_ref *parent_ref)
{
	int ret;
	u64 ino = parent_ref->dir;
	u64 parent_ino_before, parent_ino_after;
3185
	u64 old_gen;
3186 3187 3188
	struct fs_path *path_before = NULL;
	struct fs_path *path_after = NULL;
	int len1, len2;
3189 3190
	int register_upper_dirs;
	u64 gen;
3191 3192 3193 3194

	if (is_waiting_for_move(sctx, ino))
		return 1;

3195 3196 3197
	if (parent_ref->dir <= sctx->cur_ino)
		return 0;

3198 3199 3200 3201 3202 3203 3204
	ret = get_inode_info(sctx->parent_root, ino, NULL, &old_gen,
			     NULL, NULL, NULL, NULL);
	if (ret == -ENOENT)
		return 0;
	else if (ret < 0)
		return ret;

3205
	if (parent_ref->dir_gen != old_gen)
3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227
		return 0;

	path_before = fs_path_alloc();
	if (!path_before)
		return -ENOMEM;

	ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
			    NULL, path_before);
	if (ret == -ENOENT) {
		ret = 0;
		goto out;
	} else if (ret < 0) {
		goto out;
	}

	path_after = fs_path_alloc();
	if (!path_after) {
		ret = -ENOMEM;
		goto out;
	}

	ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
3228
			    &gen, path_after);
3229 3230 3231 3232 3233 3234 3235 3236 3237
	if (ret == -ENOENT) {
		ret = 0;
		goto out;
	} else if (ret < 0) {
		goto out;
	}

	len1 = fs_path_len(path_before);
	len2 = fs_path_len(path_after);
3238 3239
	if (parent_ino_before != parent_ino_after || len1 != len2 ||
	     memcmp(path_before->start, path_after->start, len1)) {
3240 3241 3242 3243 3244
		ret = 1;
		goto out;
	}
	ret = 0;

3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298
	/*
	 * Ok, our new most direct ancestor has a higher inode number but
	 * wasn't moved/renamed. So maybe some of the new ancestors higher in
	 * the hierarchy have an higher inode number too *and* were renamed
	 * or moved - in this case we need to wait for the ancestor's rename
	 * or move operation before we can do the move/rename for the current
	 * inode.
	 */
	register_upper_dirs = 0;
	ino = parent_ino_after;
again:
	while ((ret == 0 || register_upper_dirs) && ino > sctx->cur_ino) {
		u64 parent_gen;

		fs_path_reset(path_before);
		fs_path_reset(path_after);

		ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
				    &parent_gen, path_after);
		if (ret < 0)
			goto out;
		ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
				    NULL, path_before);
		if (ret == -ENOENT) {
			ret = 0;
			break;
		} else if (ret < 0) {
			goto out;
		}

		len1 = fs_path_len(path_before);
		len2 = fs_path_len(path_after);
		if (parent_ino_before != parent_ino_after || len1 != len2 ||
		    memcmp(path_before->start, path_after->start, len1)) {
			ret = 1;
			if (register_upper_dirs) {
				break;
			} else {
				register_upper_dirs = 1;
				ino = parent_ref->dir;
				gen = parent_ref->dir_gen;
				goto again;
			}
		} else if (register_upper_dirs) {
			ret = add_pending_dir_move(sctx, ino, gen,
						   parent_ino_after);
			if (ret < 0 && ret != -EEXIST)
				goto out;
		}

		ino = parent_ino_after;
		gen = parent_gen;
	}

3299 3300 3301 3302 3303 3304 3305
out:
	fs_path_free(path_before);
	fs_path_free(path_after);

	return ret;
}

3306 3307 3308
/*
 * This does all the move/link/unlink/rmdir magic.
 */
3309
static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
3310 3311 3312
{
	int ret = 0;
	struct recorded_ref *cur;
3313
	struct recorded_ref *cur2;
3314
	struct list_head check_dirs;
3315
	struct fs_path *valid_path = NULL;
3316
	u64 ow_inode = 0;
3317 3318 3319
	u64 ow_gen;
	int did_overwrite = 0;
	int is_orphan = 0;
3320
	u64 last_dir_ino_rm = 0;
3321 3322 3323

verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);

3324 3325 3326 3327 3328
	/*
	 * This should never happen as the root dir always has the same ref
	 * which is always '..'
	 */
	BUG_ON(sctx->cur_ino <= BTRFS_FIRST_FREE_OBJECTID);
3329
	INIT_LIST_HEAD(&check_dirs);
3330

3331
	valid_path = fs_path_alloc();
3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369
	if (!valid_path) {
		ret = -ENOMEM;
		goto out;
	}

	/*
	 * First, check if the first ref of the current inode was overwritten
	 * before. If yes, we know that the current inode was already orphanized
	 * and thus use the orphan name. If not, we can use get_cur_path to
	 * get the path of the first ref as it would like while receiving at
	 * this point in time.
	 * New inodes are always orphan at the beginning, so force to use the
	 * orphan name in this case.
	 * The first ref is stored in valid_path and will be updated if it
	 * gets moved around.
	 */
	if (!sctx->cur_inode_new) {
		ret = did_overwrite_first_ref(sctx, sctx->cur_ino,
				sctx->cur_inode_gen);
		if (ret < 0)
			goto out;
		if (ret)
			did_overwrite = 1;
	}
	if (sctx->cur_inode_new || did_overwrite) {
		ret = gen_unique_name(sctx, sctx->cur_ino,
				sctx->cur_inode_gen, valid_path);
		if (ret < 0)
			goto out;
		is_orphan = 1;
	} else {
		ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen,
				valid_path);
		if (ret < 0)
			goto out;
	}

	list_for_each_entry(cur, &sctx->new_refs, list) {
3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409
		/*
		 * We may have refs where the parent directory does not exist
		 * yet. This happens if the parent directories inum is higher
		 * the the current inum. To handle this case, we create the
		 * parent directory out of order. But we need to check if this
		 * did already happen before due to other refs in the same dir.
		 */
		ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
		if (ret < 0)
			goto out;
		if (ret == inode_state_will_create) {
			ret = 0;
			/*
			 * First check if any of the current inodes refs did
			 * already create the dir.
			 */
			list_for_each_entry(cur2, &sctx->new_refs, list) {
				if (cur == cur2)
					break;
				if (cur2->dir == cur->dir) {
					ret = 1;
					break;
				}
			}

			/*
			 * If that did not happen, check if a previous inode
			 * did already create the dir.
			 */
			if (!ret)
				ret = did_create_dir(sctx, cur->dir);
			if (ret < 0)
				goto out;
			if (!ret) {
				ret = send_create_inode(sctx, cur->dir);
				if (ret < 0)
					goto out;
			}
		}

3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421
		/*
		 * Check if this new ref would overwrite the first ref of
		 * another unprocessed inode. If yes, orphanize the
		 * overwritten inode. If we find an overwritten ref that is
		 * not the first ref, simply unlink it.
		 */
		ret = will_overwrite_ref(sctx, cur->dir, cur->dir_gen,
				cur->name, cur->name_len,
				&ow_inode, &ow_gen);
		if (ret < 0)
			goto out;
		if (ret) {
3422 3423 3424
			ret = is_first_ref(sctx->parent_root,
					   ow_inode, cur->dir, cur->name,
					   cur->name_len);
3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443
			if (ret < 0)
				goto out;
			if (ret) {
				ret = orphanize_inode(sctx, ow_inode, ow_gen,
						cur->full_path);
				if (ret < 0)
					goto out;
			} else {
				ret = send_unlink(sctx, cur->full_path);
				if (ret < 0)
					goto out;
			}
		}

		/*
		 * link/move the ref to the new place. If we have an orphan
		 * inode, move it and update valid_path. If not, link or move
		 * it depending on the inode mode.
		 */
3444
		if (is_orphan) {
3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458
			ret = send_rename(sctx, valid_path, cur->full_path);
			if (ret < 0)
				goto out;
			is_orphan = 0;
			ret = fs_path_copy(valid_path, cur->full_path);
			if (ret < 0)
				goto out;
		} else {
			if (S_ISDIR(sctx->cur_inode_mode)) {
				/*
				 * Dirs can't be linked, so move it. For moved
				 * dirs, we always have one new and one deleted
				 * ref. The deleted ref is ignored later.
				 */
3459 3460 3461 3462
				ret = wait_for_parent_move(sctx, cur);
				if (ret < 0)
					goto out;
				if (ret) {
3463
					ret = add_pending_dir_move(sctx,
3464 3465 3466
							   sctx->cur_ino,
							   sctx->cur_inode_gen,
							   cur->dir);
3467 3468 3469 3470 3471 3472 3473 3474
					*pending_move = 1;
				} else {
					ret = send_rename(sctx, valid_path,
							  cur->full_path);
					if (!ret)
						ret = fs_path_copy(valid_path,
							       cur->full_path);
				}
3475 3476 3477 3478 3479 3480 3481 3482 3483
				if (ret < 0)
					goto out;
			} else {
				ret = send_link(sctx, cur->full_path,
						valid_path);
				if (ret < 0)
					goto out;
			}
		}
3484
		ret = dup_ref(cur, &check_dirs);
3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495
		if (ret < 0)
			goto out;
	}

	if (S_ISDIR(sctx->cur_inode_mode) && sctx->cur_inode_deleted) {
		/*
		 * Check if we can already rmdir the directory. If not,
		 * orphanize it. For every dir item inside that gets deleted
		 * later, we do this check again and rmdir it then if possible.
		 * See the use of check_dirs for more details.
		 */
3496 3497
		ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
				sctx->cur_ino);
3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512
		if (ret < 0)
			goto out;
		if (ret) {
			ret = send_rmdir(sctx, valid_path);
			if (ret < 0)
				goto out;
		} else if (!is_orphan) {
			ret = orphanize_inode(sctx, sctx->cur_ino,
					sctx->cur_inode_gen, valid_path);
			if (ret < 0)
				goto out;
			is_orphan = 1;
		}

		list_for_each_entry(cur, &sctx->deleted_refs, list) {
3513
			ret = dup_ref(cur, &check_dirs);
3514 3515 3516
			if (ret < 0)
				goto out;
		}
3517 3518 3519 3520 3521 3522 3523
	} else if (S_ISDIR(sctx->cur_inode_mode) &&
		   !list_empty(&sctx->deleted_refs)) {
		/*
		 * We have a moved dir. Add the old parent to check_dirs
		 */
		cur = list_entry(sctx->deleted_refs.next, struct recorded_ref,
				list);
3524
		ret = dup_ref(cur, &check_dirs);
3525 3526
		if (ret < 0)
			goto out;
3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539
	} else if (!S_ISDIR(sctx->cur_inode_mode)) {
		/*
		 * We have a non dir inode. Go through all deleted refs and
		 * unlink them if they were not already overwritten by other
		 * inodes.
		 */
		list_for_each_entry(cur, &sctx->deleted_refs, list) {
			ret = did_overwrite_ref(sctx, cur->dir, cur->dir_gen,
					sctx->cur_ino, sctx->cur_inode_gen,
					cur->name, cur->name_len);
			if (ret < 0)
				goto out;
			if (!ret) {
3540 3541 3542
				ret = send_unlink(sctx, cur->full_path);
				if (ret < 0)
					goto out;
3543
			}
3544
			ret = dup_ref(cur, &check_dirs);
3545 3546 3547 3548 3549 3550 3551
			if (ret < 0)
				goto out;
		}
		/*
		 * If the inode is still orphan, unlink the orphan. This may
		 * happen when a previous inode did overwrite the first ref
		 * of this inode and no new refs were added for the current
3552 3553 3554
		 * inode. Unlinking does not mean that the inode is deleted in
		 * all cases. There may still be links to this inode in other
		 * places.
3555
		 */
3556
		if (is_orphan) {
3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568
			ret = send_unlink(sctx, valid_path);
			if (ret < 0)
				goto out;
		}
	}

	/*
	 * We did collect all parent dirs where cur_inode was once located. We
	 * now go through all these dirs and check if they are pending for
	 * deletion and if it's finally possible to perform the rmdir now.
	 * We also update the inode stats of the parent dirs here.
	 */
3569
	list_for_each_entry(cur, &check_dirs, list) {
3570 3571 3572 3573 3574
		/*
		 * In case we had refs into dirs that were not processed yet,
		 * we don't need to do the utime and rmdir logic for these dirs.
		 * The dir will be processed later.
		 */
3575
		if (cur->dir > sctx->cur_ino)
3576 3577
			continue;

3578
		ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3579 3580 3581 3582 3583 3584
		if (ret < 0)
			goto out;

		if (ret == inode_state_did_create ||
		    ret == inode_state_no_change) {
			/* TODO delayed utimes */
3585
			ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3586 3587
			if (ret < 0)
				goto out;
3588 3589
		} else if (ret == inode_state_did_delete &&
			   cur->dir != last_dir_ino_rm) {
3590 3591
			ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
					sctx->cur_ino);
3592 3593 3594
			if (ret < 0)
				goto out;
			if (ret) {
3595 3596
				ret = get_cur_path(sctx, cur->dir,
						   cur->dir_gen, valid_path);
3597 3598 3599 3600 3601
				if (ret < 0)
					goto out;
				ret = send_rmdir(sctx, valid_path);
				if (ret < 0)
					goto out;
3602
				last_dir_ino_rm = cur->dir;
3603 3604 3605 3606 3607 3608 3609
			}
		}
	}

	ret = 0;

out:
3610
	__free_recorded_refs(&check_dirs);
3611
	free_recorded_refs(sctx);
3612
	fs_path_free(valid_path);
3613 3614 3615
	return ret;
}

3616 3617
static int record_ref(struct btrfs_root *root, int num, u64 dir, int index,
		      struct fs_path *name, void *ctx, struct list_head *refs)
3618 3619 3620 3621 3622 3623
{
	int ret = 0;
	struct send_ctx *sctx = ctx;
	struct fs_path *p;
	u64 gen;

3624
	p = fs_path_alloc();
3625 3626 3627
	if (!p)
		return -ENOMEM;

3628
	ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
3629
			NULL, NULL);
3630 3631 3632 3633 3634 3635 3636 3637 3638 3639
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, dir, gen, p);
	if (ret < 0)
		goto out;
	ret = fs_path_add_path(p, name);
	if (ret < 0)
		goto out;

3640
	ret = __record_ref(refs, dir, gen, p);
3641 3642 3643

out:
	if (ret)
3644
		fs_path_free(p);
3645 3646 3647
	return ret;
}

3648 3649 3650 3651 3652 3653 3654 3655 3656 3657
static int __record_new_ref(int num, u64 dir, int index,
			    struct fs_path *name,
			    void *ctx)
{
	struct send_ctx *sctx = ctx;
	return record_ref(sctx->send_root, num, dir, index, name,
			  ctx, &sctx->new_refs);
}


3658 3659 3660 3661 3662
static int __record_deleted_ref(int num, u64 dir, int index,
				struct fs_path *name,
				void *ctx)
{
	struct send_ctx *sctx = ctx;
3663 3664
	return record_ref(sctx->parent_root, num, dir, index, name,
			  ctx, &sctx->deleted_refs);
3665 3666 3667 3668 3669 3670
}

static int record_new_ref(struct send_ctx *sctx)
{
	int ret;

3671 3672
	ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
				sctx->cmp_key, 0, __record_new_ref, sctx);
3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684
	if (ret < 0)
		goto out;
	ret = 0;

out:
	return ret;
}

static int record_deleted_ref(struct send_ctx *sctx)
{
	int ret;

3685 3686
	ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
				sctx->cmp_key, 0, __record_deleted_ref, sctx);
3687 3688 3689 3690 3691 3692 3693 3694 3695 3696
	if (ret < 0)
		goto out;
	ret = 0;

out:
	return ret;
}

struct find_ref_ctx {
	u64 dir;
3697 3698
	u64 dir_gen;
	struct btrfs_root *root;
3699 3700 3701 3702 3703 3704 3705 3706 3707
	struct fs_path *name;
	int found_idx;
};

static int __find_iref(int num, u64 dir, int index,
		       struct fs_path *name,
		       void *ctx_)
{
	struct find_ref_ctx *ctx = ctx_;
3708 3709
	u64 dir_gen;
	int ret;
3710 3711 3712

	if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
	    strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
3713 3714 3715 3716 3717 3718 3719 3720 3721 3722
		/*
		 * To avoid doing extra lookups we'll only do this if everything
		 * else matches.
		 */
		ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
				     NULL, NULL, NULL);
		if (ret)
			return ret;
		if (dir_gen != ctx->dir_gen)
			return 0;
3723 3724 3725 3726 3727 3728
		ctx->found_idx = num;
		return 1;
	}
	return 0;
}

3729
static int find_iref(struct btrfs_root *root,
3730 3731
		     struct btrfs_path *path,
		     struct btrfs_key *key,
3732
		     u64 dir, u64 dir_gen, struct fs_path *name)
3733 3734 3735 3736 3737 3738
{
	int ret;
	struct find_ref_ctx ctx;

	ctx.dir = dir;
	ctx.name = name;
3739
	ctx.dir_gen = dir_gen;
3740
	ctx.found_idx = -1;
3741
	ctx.root = root;
3742

3743
	ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756
	if (ret < 0)
		return ret;

	if (ctx.found_idx == -1)
		return -ENOENT;

	return ctx.found_idx;
}

static int __record_changed_new_ref(int num, u64 dir, int index,
				    struct fs_path *name,
				    void *ctx)
{
3757
	u64 dir_gen;
3758 3759 3760
	int ret;
	struct send_ctx *sctx = ctx;

3761 3762 3763 3764 3765
	ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
			     NULL, NULL, NULL);
	if (ret)
		return ret;

3766
	ret = find_iref(sctx->parent_root, sctx->right_path,
3767
			sctx->cmp_key, dir, dir_gen, name);
3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779
	if (ret == -ENOENT)
		ret = __record_new_ref(num, dir, index, name, sctx);
	else if (ret > 0)
		ret = 0;

	return ret;
}

static int __record_changed_deleted_ref(int num, u64 dir, int index,
					struct fs_path *name,
					void *ctx)
{
3780
	u64 dir_gen;
3781 3782 3783
	int ret;
	struct send_ctx *sctx = ctx;

3784 3785 3786 3787 3788
	ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
			     NULL, NULL, NULL);
	if (ret)
		return ret;

3789
	ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
3790
			dir, dir_gen, name);
3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802
	if (ret == -ENOENT)
		ret = __record_deleted_ref(num, dir, index, name, sctx);
	else if (ret > 0)
		ret = 0;

	return ret;
}

static int record_changed_ref(struct send_ctx *sctx)
{
	int ret = 0;

3803
	ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3804 3805 3806
			sctx->cmp_key, 0, __record_changed_new_ref, sctx);
	if (ret < 0)
		goto out;
3807
	ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831
			sctx->cmp_key, 0, __record_changed_deleted_ref, sctx);
	if (ret < 0)
		goto out;
	ret = 0;

out:
	return ret;
}

/*
 * Record and process all refs at once. Needed when an inode changes the
 * generation number, which means that it was deleted and recreated.
 */
static int process_all_refs(struct send_ctx *sctx,
			    enum btrfs_compare_tree_result cmd)
{
	int ret;
	struct btrfs_root *root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct extent_buffer *eb;
	int slot;
	iterate_inode_ref_t cb;
3832
	int pending_move = 0;
3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	if (cmd == BTRFS_COMPARE_TREE_NEW) {
		root = sctx->send_root;
		cb = __record_new_ref;
	} else if (cmd == BTRFS_COMPARE_TREE_DELETED) {
		root = sctx->parent_root;
		cb = __record_deleted_ref;
	} else {
3845 3846 3847 3848
		btrfs_err(sctx->send_root->fs_info,
				"Wrong command %d in process_all_refs", cmd);
		ret = -EINVAL;
		goto out;
3849 3850 3851 3852 3853
	}

	key.objectid = sctx->cmp_key->objectid;
	key.type = BTRFS_INODE_REF_KEY;
	key.offset = 0;
3854 3855 3856
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
3857

3858
	while (1) {
3859 3860
		eb = path->nodes[0];
		slot = path->slots[0];
3861 3862 3863 3864 3865 3866 3867 3868 3869
		if (slot >= btrfs_header_nritems(eb)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				goto out;
			else if (ret > 0)
				break;
			continue;
		}

3870 3871 3872
		btrfs_item_key_to_cpu(eb, &found_key, slot);

		if (found_key.objectid != key.objectid ||
3873 3874
		    (found_key.type != BTRFS_INODE_REF_KEY &&
		     found_key.type != BTRFS_INODE_EXTREF_KEY))
3875 3876
			break;

3877
		ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
3878 3879 3880
		if (ret < 0)
			goto out;

3881
		path->slots[0]++;
3882
	}
3883
	btrfs_release_path(path);
3884

3885 3886 3887
	ret = process_recorded_refs(sctx, &pending_move);
	/* Only applicable to an incremental send. */
	ASSERT(pending_move == 0);
3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945

out:
	btrfs_free_path(path);
	return ret;
}

static int send_set_xattr(struct send_ctx *sctx,
			  struct fs_path *path,
			  const char *name, int name_len,
			  const char *data, int data_len)
{
	int ret = 0;

	ret = begin_cmd(sctx, BTRFS_SEND_C_SET_XATTR);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
	TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);
	TLV_PUT(sctx, BTRFS_SEND_A_XATTR_DATA, data, data_len);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
	return ret;
}

static int send_remove_xattr(struct send_ctx *sctx,
			  struct fs_path *path,
			  const char *name, int name_len)
{
	int ret = 0;

	ret = begin_cmd(sctx, BTRFS_SEND_C_REMOVE_XATTR);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path);
	TLV_PUT_STRING(sctx, BTRFS_SEND_A_XATTR_NAME, name, name_len);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
	return ret;
}

static int __process_new_xattr(int num, struct btrfs_key *di_key,
			       const char *name, int name_len,
			       const char *data, int data_len,
			       u8 type, void *ctx)
{
	int ret;
	struct send_ctx *sctx = ctx;
	struct fs_path *p;
	posix_acl_xattr_header dummy_acl;

3946
	p = fs_path_alloc();
3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972
	if (!p)
		return -ENOMEM;

	/*
	 * This hack is needed because empty acl's are stored as zero byte
	 * data in xattrs. Problem with that is, that receiving these zero byte
	 * acl's will fail later. To fix this, we send a dummy acl list that
	 * only contains the version number and no entries.
	 */
	if (!strncmp(name, XATTR_NAME_POSIX_ACL_ACCESS, name_len) ||
	    !strncmp(name, XATTR_NAME_POSIX_ACL_DEFAULT, name_len)) {
		if (data_len == 0) {
			dummy_acl.a_version =
					cpu_to_le32(POSIX_ACL_XATTR_VERSION);
			data = (char *)&dummy_acl;
			data_len = sizeof(dummy_acl);
		}
	}

	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
	if (ret < 0)
		goto out;

	ret = send_set_xattr(sctx, p, name, name_len, data, data_len);

out:
3973
	fs_path_free(p);
3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985
	return ret;
}

static int __process_deleted_xattr(int num, struct btrfs_key *di_key,
				   const char *name, int name_len,
				   const char *data, int data_len,
				   u8 type, void *ctx)
{
	int ret;
	struct send_ctx *sctx = ctx;
	struct fs_path *p;

3986
	p = fs_path_alloc();
3987 3988 3989 3990 3991 3992 3993 3994 3995 3996
	if (!p)
		return -ENOMEM;

	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
	if (ret < 0)
		goto out;

	ret = send_remove_xattr(sctx, p, name, name_len);

out:
3997
	fs_path_free(p);
3998 3999 4000 4001 4002 4003 4004
	return ret;
}

static int process_new_xattr(struct send_ctx *sctx)
{
	int ret = 0;

4005 4006
	ret = iterate_dir_item(sctx->send_root, sctx->left_path,
			       sctx->cmp_key, __process_new_xattr, sctx);
4007 4008 4009 4010 4011 4012 4013 4014

	return ret;
}

static int process_deleted_xattr(struct send_ctx *sctx)
{
	int ret;

4015 4016
	ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
			       sctx->cmp_key, __process_deleted_xattr, sctx);
4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039

	return ret;
}

struct find_xattr_ctx {
	const char *name;
	int name_len;
	int found_idx;
	char *found_data;
	int found_data_len;
};

static int __find_xattr(int num, struct btrfs_key *di_key,
			const char *name, int name_len,
			const char *data, int data_len,
			u8 type, void *vctx)
{
	struct find_xattr_ctx *ctx = vctx;

	if (name_len == ctx->name_len &&
	    strncmp(name, ctx->name, name_len) == 0) {
		ctx->found_idx = num;
		ctx->found_data_len = data_len;
4040
		ctx->found_data = kmemdup(data, data_len, GFP_NOFS);
4041 4042 4043 4044 4045 4046 4047
		if (!ctx->found_data)
			return -ENOMEM;
		return 1;
	}
	return 0;
}

4048
static int find_xattr(struct btrfs_root *root,
4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062
		      struct btrfs_path *path,
		      struct btrfs_key *key,
		      const char *name, int name_len,
		      char **data, int *data_len)
{
	int ret;
	struct find_xattr_ctx ctx;

	ctx.name = name;
	ctx.name_len = name_len;
	ctx.found_idx = -1;
	ctx.found_data = NULL;
	ctx.found_data_len = 0;

4063
	ret = iterate_dir_item(root, path, key, __find_xattr, &ctx);
4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088
	if (ret < 0)
		return ret;

	if (ctx.found_idx == -1)
		return -ENOENT;
	if (data) {
		*data = ctx.found_data;
		*data_len = ctx.found_data_len;
	} else {
		kfree(ctx.found_data);
	}
	return ctx.found_idx;
}


static int __process_changed_new_xattr(int num, struct btrfs_key *di_key,
				       const char *name, int name_len,
				       const char *data, int data_len,
				       u8 type, void *ctx)
{
	int ret;
	struct send_ctx *sctx = ctx;
	char *found_data = NULL;
	int found_data_len  = 0;

4089 4090 4091
	ret = find_xattr(sctx->parent_root, sctx->right_path,
			 sctx->cmp_key, name, name_len, &found_data,
			 &found_data_len);
4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116
	if (ret == -ENOENT) {
		ret = __process_new_xattr(num, di_key, name, name_len, data,
				data_len, type, ctx);
	} else if (ret >= 0) {
		if (data_len != found_data_len ||
		    memcmp(data, found_data, data_len)) {
			ret = __process_new_xattr(num, di_key, name, name_len,
					data, data_len, type, ctx);
		} else {
			ret = 0;
		}
	}

	kfree(found_data);
	return ret;
}

static int __process_changed_deleted_xattr(int num, struct btrfs_key *di_key,
					   const char *name, int name_len,
					   const char *data, int data_len,
					   u8 type, void *ctx)
{
	int ret;
	struct send_ctx *sctx = ctx;

4117 4118
	ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
			 name, name_len, NULL, NULL);
4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131
	if (ret == -ENOENT)
		ret = __process_deleted_xattr(num, di_key, name, name_len, data,
				data_len, type, ctx);
	else if (ret >= 0)
		ret = 0;

	return ret;
}

static int process_changed_xattr(struct send_ctx *sctx)
{
	int ret = 0;

4132
	ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4133 4134 4135
			sctx->cmp_key, __process_changed_new_xattr, sctx);
	if (ret < 0)
		goto out;
4136
	ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161
			sctx->cmp_key, __process_changed_deleted_xattr, sctx);

out:
	return ret;
}

static int process_all_new_xattrs(struct send_ctx *sctx)
{
	int ret;
	struct btrfs_root *root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct extent_buffer *eb;
	int slot;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	root = sctx->send_root;

	key.objectid = sctx->cmp_key->objectid;
	key.type = BTRFS_XATTR_ITEM_KEY;
	key.offset = 0;
4162 4163 4164
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
4165

4166
	while (1) {
4167 4168
		eb = path->nodes[0];
		slot = path->slots[0];
4169 4170 4171 4172 4173 4174 4175 4176 4177 4178
		if (slot >= btrfs_header_nritems(eb)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0) {
				goto out;
			} else if (ret > 0) {
				ret = 0;
				break;
			}
			continue;
		}
4179

4180
		btrfs_item_key_to_cpu(eb, &found_key, slot);
4181 4182 4183 4184 4185 4186
		if (found_key.objectid != key.objectid ||
		    found_key.type != key.type) {
			ret = 0;
			goto out;
		}

4187 4188
		ret = iterate_dir_item(root, path, &found_key,
				       __process_new_xattr, sctx);
4189 4190 4191
		if (ret < 0)
			goto out;

4192
		path->slots[0]++;
4193 4194 4195 4196 4197 4198 4199
	}

out:
	btrfs_free_path(path);
	return ret;
}

J
Josef Bacik 已提交
4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230
static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len)
{
	struct btrfs_root *root = sctx->send_root;
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct inode *inode;
	struct page *page;
	char *addr;
	struct btrfs_key key;
	pgoff_t index = offset >> PAGE_CACHE_SHIFT;
	pgoff_t last_index;
	unsigned pg_offset = offset & ~PAGE_CACHE_MASK;
	ssize_t ret = 0;

	key.objectid = sctx->cur_ino;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;

	inode = btrfs_iget(fs_info->sb, &key, root, NULL);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	if (offset + len > i_size_read(inode)) {
		if (offset > i_size_read(inode))
			len = 0;
		else
			len = offset - i_size_read(inode);
	}
	if (len == 0)
		goto out;

	last_index = (offset + len - 1) >> PAGE_CACHE_SHIFT;
L
Liu Bo 已提交
4231 4232 4233 4234 4235 4236 4237

	/* initial readahead */
	memset(&sctx->ra, 0, sizeof(struct file_ra_state));
	file_ra_state_init(&sctx->ra, inode->i_mapping);
	btrfs_force_ra(inode->i_mapping, &sctx->ra, NULL, index,
		       last_index - index + 1);

J
Josef Bacik 已提交
4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272
	while (index <= last_index) {
		unsigned cur_len = min_t(unsigned, len,
					 PAGE_CACHE_SIZE - pg_offset);
		page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
		if (!page) {
			ret = -ENOMEM;
			break;
		}

		if (!PageUptodate(page)) {
			btrfs_readpage(NULL, page);
			lock_page(page);
			if (!PageUptodate(page)) {
				unlock_page(page);
				page_cache_release(page);
				ret = -EIO;
				break;
			}
		}

		addr = kmap(page);
		memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len);
		kunmap(page);
		unlock_page(page);
		page_cache_release(page);
		index++;
		pg_offset = 0;
		len -= cur_len;
		ret += cur_len;
	}
out:
	iput(inode);
	return ret;
}

4273 4274 4275 4276 4277 4278 4279 4280
/*
 * Read some bytes from the current inode/file and send a write command to
 * user space.
 */
static int send_write(struct send_ctx *sctx, u64 offset, u32 len)
{
	int ret = 0;
	struct fs_path *p;
J
Josef Bacik 已提交
4281
	ssize_t num_read = 0;
4282

4283
	p = fs_path_alloc();
4284 4285 4286 4287 4288
	if (!p)
		return -ENOMEM;

verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len);

J
Josef Bacik 已提交
4289 4290 4291 4292
	num_read = fill_read_buf(sctx, offset, len);
	if (num_read <= 0) {
		if (num_read < 0)
			ret = num_read;
4293
		goto out;
J
Josef Bacik 已提交
4294
	}
4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305

	ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
4306
	TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
4307 4308 4309 4310 4311

	ret = send_cmd(sctx);

tlv_put_failure:
out:
4312
	fs_path_free(p);
4313 4314
	if (ret < 0)
		return ret;
4315
	return num_read;
4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333
}

/*
 * Send a clone command to user space.
 */
static int send_clone(struct send_ctx *sctx,
		      u64 offset, u32 len,
		      struct clone_root *clone_root)
{
	int ret = 0;
	struct fs_path *p;
	u64 gen;

verbose_printk("btrfs: send_clone offset=%llu, len=%d, clone_root=%llu, "
	       "clone_inode=%llu, clone_offset=%llu\n", offset, len,
		clone_root->root->objectid, clone_root->ino,
		clone_root->offset);

4334
	p = fs_path_alloc();
4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349
	if (!p)
		return -ENOMEM;

	ret = begin_cmd(sctx, BTRFS_SEND_C_CLONE);
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
	if (ret < 0)
		goto out;

	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_LEN, len);
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);

4350
	if (clone_root->root == sctx->send_root) {
4351
		ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
4352
				&gen, NULL, NULL, NULL, NULL);
4353 4354 4355 4356
		if (ret < 0)
			goto out;
		ret = get_cur_path(sctx, clone_root->ino, gen, p);
	} else {
4357
		ret = get_inode_path(clone_root->root, clone_root->ino, p);
4358 4359 4360 4361 4362
	}
	if (ret < 0)
		goto out;

	TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4363
			clone_root->root->root_item.uuid);
4364
	TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
4365
		    le64_to_cpu(clone_root->root->root_item.ctransid));
4366 4367 4368 4369 4370 4371 4372 4373
	TLV_PUT_PATH(sctx, BTRFS_SEND_A_CLONE_PATH, p);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_OFFSET,
			clone_root->offset);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
4374
	fs_path_free(p);
4375 4376 4377
	return ret;
}

4378 4379 4380 4381 4382 4383 4384 4385 4386
/*
 * Send an update extent command to user space.
 */
static int send_update_extent(struct send_ctx *sctx,
			      u64 offset, u32 len)
{
	int ret = 0;
	struct fs_path *p;

4387
	p = fs_path_alloc();
4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406
	if (!p)
		return -ENOMEM;

	ret = begin_cmd(sctx, BTRFS_SEND_C_UPDATE_EXTENT);
	if (ret < 0)
		goto out;

	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
	TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len);

	ret = send_cmd(sctx);

tlv_put_failure:
out:
4407
	fs_path_free(p);
4408 4409 4410
	return ret;
}

4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443
static int send_hole(struct send_ctx *sctx, u64 end)
{
	struct fs_path *p = NULL;
	u64 offset = sctx->cur_inode_last_extent;
	u64 len;
	int ret = 0;

	p = fs_path_alloc();
	if (!p)
		return -ENOMEM;
	memset(sctx->read_buf, 0, BTRFS_SEND_READ_SIZE);
	while (offset < end) {
		len = min_t(u64, end - offset, BTRFS_SEND_READ_SIZE);

		ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE);
		if (ret < 0)
			break;
		ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
		if (ret < 0)
			break;
		TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
		TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset);
		TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len);
		ret = send_cmd(sctx);
		if (ret < 0)
			break;
		offset += len;
	}
tlv_put_failure:
	fs_path_free(p);
	return ret;
}

4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455
static int send_write_or_clone(struct send_ctx *sctx,
			       struct btrfs_path *path,
			       struct btrfs_key *key,
			       struct clone_root *clone_root)
{
	int ret = 0;
	struct btrfs_file_extent_item *ei;
	u64 offset = key->offset;
	u64 pos = 0;
	u64 len;
	u32 l;
	u8 type;
4456
	u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
4457 4458 4459 4460

	ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
			struct btrfs_file_extent_item);
	type = btrfs_file_extent_type(path->nodes[0], ei);
4461
	if (type == BTRFS_FILE_EXTENT_INLINE) {
4462 4463
		len = btrfs_file_extent_inline_len(path->nodes[0],
						   path->slots[0], ei);
4464 4465 4466 4467 4468 4469 4470
		/*
		 * it is possible the inline item won't cover the whole page,
		 * but there may be items after this page.  Make
		 * sure to send the whole thing
		 */
		len = PAGE_CACHE_ALIGN(len);
	} else {
4471
		len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
4472
	}
4473 4474 4475 4476 4477 4478 4479 4480

	if (offset + len > sctx->cur_inode_size)
		len = sctx->cur_inode_size - offset;
	if (len == 0) {
		ret = 0;
		goto out;
	}

4481
	if (clone_root && IS_ALIGNED(offset + len, bs)) {
4482 4483 4484 4485
		ret = send_clone(sctx, offset, len, clone_root);
	} else if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) {
		ret = send_update_extent(sctx, offset, len);
	} else {
4486 4487 4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502 4503 4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520
		while (pos < len) {
			l = len - pos;
			if (l > BTRFS_SEND_READ_SIZE)
				l = BTRFS_SEND_READ_SIZE;
			ret = send_write(sctx, pos + offset, l);
			if (ret < 0)
				goto out;
			if (!ret)
				break;
			pos += ret;
		}
		ret = 0;
	}
out:
	return ret;
}

static int is_extent_unchanged(struct send_ctx *sctx,
			       struct btrfs_path *left_path,
			       struct btrfs_key *ekey)
{
	int ret = 0;
	struct btrfs_key key;
	struct btrfs_path *path = NULL;
	struct extent_buffer *eb;
	int slot;
	struct btrfs_key found_key;
	struct btrfs_file_extent_item *ei;
	u64 left_disknr;
	u64 right_disknr;
	u64 left_offset;
	u64 right_offset;
	u64 left_offset_fixed;
	u64 left_len;
	u64 right_len;
4521 4522
	u64 left_gen;
	u64 right_gen;
4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538
	u8 left_type;
	u8 right_type;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	eb = left_path->nodes[0];
	slot = left_path->slots[0];
	ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
	left_type = btrfs_file_extent_type(eb, ei);

	if (left_type != BTRFS_FILE_EXTENT_REG) {
		ret = 0;
		goto out;
	}
4539 4540 4541 4542
	left_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
	left_len = btrfs_file_extent_num_bytes(eb, ei);
	left_offset = btrfs_file_extent_offset(eb, ei);
	left_gen = btrfs_file_extent_generation(eb, ei);
4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583

	/*
	 * Following comments will refer to these graphics. L is the left
	 * extents which we are checking at the moment. 1-8 are the right
	 * extents that we iterate.
	 *
	 *       |-----L-----|
	 * |-1-|-2a-|-3-|-4-|-5-|-6-|
	 *
	 *       |-----L-----|
	 * |--1--|-2b-|...(same as above)
	 *
	 * Alternative situation. Happens on files where extents got split.
	 *       |-----L-----|
	 * |-----------7-----------|-6-|
	 *
	 * Alternative situation. Happens on files which got larger.
	 *       |-----L-----|
	 * |-8-|
	 * Nothing follows after 8.
	 */

	key.objectid = ekey->objectid;
	key.type = BTRFS_EXTENT_DATA_KEY;
	key.offset = ekey->offset;
	ret = btrfs_search_slot_for_read(sctx->parent_root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	if (ret) {
		ret = 0;
		goto out;
	}

	/*
	 * Handle special case where the right side has no extents at all.
	 */
	eb = path->nodes[0];
	slot = path->slots[0];
	btrfs_item_key_to_cpu(eb, &found_key, slot);
	if (found_key.objectid != key.objectid ||
	    found_key.type != key.type) {
4584 4585
		/* If we're a hole then just pretend nothing changed */
		ret = (left_disknr) ? 0 : 1;
4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600
		goto out;
	}

	/*
	 * We're now on 2a, 2b or 7.
	 */
	key = found_key;
	while (key.offset < ekey->offset + left_len) {
		ei = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
		right_type = btrfs_file_extent_type(eb, ei);
		if (right_type != BTRFS_FILE_EXTENT_REG) {
			ret = 0;
			goto out;
		}

4601 4602 4603 4604 4605
		right_disknr = btrfs_file_extent_disk_bytenr(eb, ei);
		right_len = btrfs_file_extent_num_bytes(eb, ei);
		right_offset = btrfs_file_extent_offset(eb, ei);
		right_gen = btrfs_file_extent_generation(eb, ei);

4606 4607 4608 4609
		/*
		 * Are we at extent 8? If yes, we know the extent is changed.
		 * This may only happen on the first iteration.
		 */
4610
		if (found_key.offset + right_len <= ekey->offset) {
4611 4612
			/* If we're a hole just pretend nothing changed */
			ret = (left_disknr) ? 0 : 1;
4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627
			goto out;
		}

		left_offset_fixed = left_offset;
		if (key.offset < ekey->offset) {
			/* Fix the right offset for 2a and 7. */
			right_offset += ekey->offset - key.offset;
		} else {
			/* Fix the left offset for all behind 2a and 2b */
			left_offset_fixed += key.offset - ekey->offset;
		}

		/*
		 * Check if we have the same extent.
		 */
4628
		if (left_disknr != right_disknr ||
4629 4630
		    left_offset_fixed != right_offset ||
		    left_gen != right_gen) {
4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649
			ret = 0;
			goto out;
		}

		/*
		 * Go to the next extent.
		 */
		ret = btrfs_next_item(sctx->parent_root, path);
		if (ret < 0)
			goto out;
		if (!ret) {
			eb = path->nodes[0];
			slot = path->slots[0];
			btrfs_item_key_to_cpu(eb, &found_key, slot);
		}
		if (ret || found_key.objectid != key.objectid ||
		    found_key.type != key.type) {
			key.offset += right_len;
			break;
4650 4651 4652 4653
		}
		if (found_key.offset != key.offset + right_len) {
			ret = 0;
			goto out;
4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672
		}
		key = found_key;
	}

	/*
	 * We're now behind the left extent (treat as unchanged) or at the end
	 * of the right side (treat as changed).
	 */
	if (key.offset >= ekey->offset + left_len)
		ret = 1;
	else
		ret = 0;


out:
	btrfs_free_path(path);
	return ret;
}

4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703
static int get_last_extent(struct send_ctx *sctx, u64 offset)
{
	struct btrfs_path *path;
	struct btrfs_root *root = sctx->send_root;
	struct btrfs_file_extent_item *fi;
	struct btrfs_key key;
	u64 extent_end;
	u8 type;
	int ret;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	sctx->cur_inode_last_extent = 0;

	key.objectid = sctx->cur_ino;
	key.type = BTRFS_EXTENT_DATA_KEY;
	key.offset = offset;
	ret = btrfs_search_slot_for_read(root, &key, path, 0, 1);
	if (ret < 0)
		goto out;
	ret = 0;
	btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
	if (key.objectid != sctx->cur_ino || key.type != BTRFS_EXTENT_DATA_KEY)
		goto out;

	fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
			    struct btrfs_file_extent_item);
	type = btrfs_file_extent_type(path->nodes[0], fi);
	if (type == BTRFS_FILE_EXTENT_INLINE) {
4704 4705
		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
							path->slots[0], fi);
4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738
		extent_end = ALIGN(key.offset + size,
				   sctx->send_root->sectorsize);
	} else {
		extent_end = key.offset +
			btrfs_file_extent_num_bytes(path->nodes[0], fi);
	}
	sctx->cur_inode_last_extent = extent_end;
out:
	btrfs_free_path(path);
	return ret;
}

static int maybe_send_hole(struct send_ctx *sctx, struct btrfs_path *path,
			   struct btrfs_key *key)
{
	struct btrfs_file_extent_item *fi;
	u64 extent_end;
	u8 type;
	int ret = 0;

	if (sctx->cur_ino != key->objectid || !need_send_hole(sctx))
		return 0;

	if (sctx->cur_inode_last_extent == (u64)-1) {
		ret = get_last_extent(sctx, key->offset - 1);
		if (ret)
			return ret;
	}

	fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
			    struct btrfs_file_extent_item);
	type = btrfs_file_extent_type(path->nodes[0], fi);
	if (type == BTRFS_FILE_EXTENT_INLINE) {
4739 4740
		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
							path->slots[0], fi);
4741 4742 4743 4744 4745 4746
		extent_end = ALIGN(key->offset + size,
				   sctx->send_root->sectorsize);
	} else {
		extent_end = key->offset +
			btrfs_file_extent_num_bytes(path->nodes[0], fi);
	}
4747 4748 4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761

	if (path->slots[0] == 0 &&
	    sctx->cur_inode_last_extent < key->offset) {
		/*
		 * We might have skipped entire leafs that contained only
		 * file extent items for our current inode. These leafs have
		 * a generation number smaller (older) than the one in the
		 * current leaf and the leaf our last extent came from, and
		 * are located between these 2 leafs.
		 */
		ret = get_last_extent(sctx, key->offset - 1);
		if (ret)
			return ret;
	}

4762 4763 4764 4765 4766 4767
	if (sctx->cur_inode_last_extent < key->offset)
		ret = send_hole(sctx, key->offset);
	sctx->cur_inode_last_extent = extent_end;
	return ret;
}

4768 4769 4770 4771 4772
static int process_extent(struct send_ctx *sctx,
			  struct btrfs_path *path,
			  struct btrfs_key *key)
{
	struct clone_root *found_clone = NULL;
4773
	int ret = 0;
4774 4775 4776 4777 4778 4779 4780 4781 4782 4783

	if (S_ISLNK(sctx->cur_inode_mode))
		return 0;

	if (sctx->parent_root && !sctx->cur_inode_new) {
		ret = is_extent_unchanged(sctx, path, key);
		if (ret < 0)
			goto out;
		if (ret) {
			ret = 0;
4784
			goto out_hole;
4785
		}
4786 4787 4788 4789 4790 4791 4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811
	} else {
		struct btrfs_file_extent_item *ei;
		u8 type;

		ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
				    struct btrfs_file_extent_item);
		type = btrfs_file_extent_type(path->nodes[0], ei);
		if (type == BTRFS_FILE_EXTENT_PREALLOC ||
		    type == BTRFS_FILE_EXTENT_REG) {
			/*
			 * The send spec does not have a prealloc command yet,
			 * so just leave a hole for prealloc'ed extents until
			 * we have enough commands queued up to justify rev'ing
			 * the send spec.
			 */
			if (type == BTRFS_FILE_EXTENT_PREALLOC) {
				ret = 0;
				goto out;
			}

			/* Have a hole, just skip it. */
			if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
				ret = 0;
				goto out;
			}
		}
4812 4813 4814 4815 4816 4817 4818 4819
	}

	ret = find_extent_clone(sctx, path, key->objectid, key->offset,
			sctx->cur_inode_size, &found_clone);
	if (ret != -ENOENT && ret < 0)
		goto out;

	ret = send_write_or_clone(sctx, path, key, found_clone);
4820 4821 4822 4823
	if (ret)
		goto out;
out_hole:
	ret = maybe_send_hole(sctx, path, key);
4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837 4838 4839 4840 4841 4842 4843 4844 4845
out:
	return ret;
}

static int process_all_extents(struct send_ctx *sctx)
{
	int ret;
	struct btrfs_root *root;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct extent_buffer *eb;
	int slot;

	root = sctx->send_root;
	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	key.objectid = sctx->cmp_key->objectid;
	key.type = BTRFS_EXTENT_DATA_KEY;
	key.offset = 0;
4846 4847 4848
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
4849

4850
	while (1) {
4851 4852
		eb = path->nodes[0];
		slot = path->slots[0];
4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864

		if (slot >= btrfs_header_nritems(eb)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0) {
				goto out;
			} else if (ret > 0) {
				ret = 0;
				break;
			}
			continue;
		}

4865 4866 4867 4868 4869 4870 4871 4872 4873 4874 4875 4876
		btrfs_item_key_to_cpu(eb, &found_key, slot);

		if (found_key.objectid != key.objectid ||
		    found_key.type != key.type) {
			ret = 0;
			goto out;
		}

		ret = process_extent(sctx, path, &found_key);
		if (ret < 0)
			goto out;

4877
		path->slots[0]++;
4878 4879 4880 4881 4882 4883 4884
	}

out:
	btrfs_free_path(path);
	return ret;
}

4885 4886 4887
static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
					   int *pending_move,
					   int *refs_processed)
4888 4889 4890 4891 4892 4893
{
	int ret = 0;

	if (sctx->cur_ino == 0)
		goto out;
	if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
4894
	    sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
4895 4896 4897 4898
		goto out;
	if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
		goto out;

4899
	ret = process_recorded_refs(sctx, pending_move);
4900 4901 4902
	if (ret < 0)
		goto out;

4903
	*refs_processed = 1;
4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918
out:
	return ret;
}

static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
{
	int ret = 0;
	u64 left_mode;
	u64 left_uid;
	u64 left_gid;
	u64 right_mode;
	u64 right_uid;
	u64 right_gid;
	int need_chmod = 0;
	int need_chown = 0;
4919 4920
	int pending_move = 0;
	int refs_processed = 0;
4921

4922 4923
	ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
					      &refs_processed);
4924 4925 4926
	if (ret < 0)
		goto out;

4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938 4939 4940 4941
	/*
	 * We have processed the refs and thus need to advance send_progress.
	 * Now, calls to get_cur_xxx will take the updated refs of the current
	 * inode into account.
	 *
	 * On the other hand, if our current inode is a directory and couldn't
	 * be moved/renamed because its parent was renamed/moved too and it has
	 * a higher inode number, we can only move/rename our current inode
	 * after we moved/renamed its parent. Therefore in this case operate on
	 * the old path (pre move/rename) of our current inode, and the
	 * move/rename will be performed later.
	 */
	if (refs_processed && !pending_move)
		sctx->send_progress = sctx->cur_ino + 1;

4942 4943 4944 4945 4946 4947
	if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
		goto out;
	if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
		goto out;

	ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
4948
			&left_mode, &left_uid, &left_gid, NULL);
4949 4950 4951
	if (ret < 0)
		goto out;

4952 4953 4954
	if (!sctx->parent_root || sctx->cur_inode_new) {
		need_chown = 1;
		if (!S_ISLNK(sctx->cur_inode_mode))
4955
			need_chmod = 1;
4956 4957 4958 4959 4960 4961
	} else {
		ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
				NULL, NULL, &right_mode, &right_uid,
				&right_gid, NULL);
		if (ret < 0)
			goto out;
4962

4963 4964 4965 4966
		if (left_uid != right_uid || left_gid != right_gid)
			need_chown = 1;
		if (!S_ISLNK(sctx->cur_inode_mode) && left_mode != right_mode)
			need_chmod = 1;
4967 4968 4969
	}

	if (S_ISREG(sctx->cur_inode_mode)) {
4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982
		if (need_send_hole(sctx)) {
			if (sctx->cur_inode_last_extent == (u64)-1) {
				ret = get_last_extent(sctx, (u64)-1);
				if (ret)
					goto out;
			}
			if (sctx->cur_inode_last_extent <
			    sctx->cur_inode_size) {
				ret = send_hole(sctx, sctx->cur_inode_size);
				if (ret)
					goto out;
			}
		}
4983 4984 4985 4986 4987 4988 4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999 5000 5001 5002
		ret = send_truncate(sctx, sctx->cur_ino, sctx->cur_inode_gen,
				sctx->cur_inode_size);
		if (ret < 0)
			goto out;
	}

	if (need_chown) {
		ret = send_chown(sctx, sctx->cur_ino, sctx->cur_inode_gen,
				left_uid, left_gid);
		if (ret < 0)
			goto out;
	}
	if (need_chmod) {
		ret = send_chmod(sctx, sctx->cur_ino, sctx->cur_inode_gen,
				left_mode);
		if (ret < 0)
			goto out;
	}

	/*
5003 5004
	 * If other directory inodes depended on our current directory
	 * inode's move/rename, now do their move/rename operations.
5005
	 */
5006 5007 5008 5009
	if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
		ret = apply_children_dir_moves(sctx);
		if (ret)
			goto out;
5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020
		/*
		 * Need to send that every time, no matter if it actually
		 * changed between the two trees as we have done changes to
		 * the inode before. If our inode is a directory and it's
		 * waiting to be moved/renamed, we will send its utimes when
		 * it's moved/renamed, therefore we don't need to do it here.
		 */
		sctx->send_progress = sctx->cur_ino + 1;
		ret = send_utimes(sctx, sctx->cur_ino, sctx->cur_inode_gen);
		if (ret < 0)
			goto out;
5021 5022
	}

5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038
out:
	return ret;
}

static int changed_inode(struct send_ctx *sctx,
			 enum btrfs_compare_tree_result result)
{
	int ret = 0;
	struct btrfs_key *key = sctx->cmp_key;
	struct btrfs_inode_item *left_ii = NULL;
	struct btrfs_inode_item *right_ii = NULL;
	u64 left_gen = 0;
	u64 right_gen = 0;

	sctx->cur_ino = key->objectid;
	sctx->cur_inode_new_gen = 0;
5039
	sctx->cur_inode_last_extent = (u64)-1;
5040 5041 5042 5043 5044 5045

	/*
	 * Set send_progress to current inode. This will tell all get_cur_xxx
	 * functions that the current inode's refs are not updated yet. Later,
	 * when process_recorded_refs is finished, it is set to cur_ino + 1.
	 */
5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068
	sctx->send_progress = sctx->cur_ino;

	if (result == BTRFS_COMPARE_TREE_NEW ||
	    result == BTRFS_COMPARE_TREE_CHANGED) {
		left_ii = btrfs_item_ptr(sctx->left_path->nodes[0],
				sctx->left_path->slots[0],
				struct btrfs_inode_item);
		left_gen = btrfs_inode_generation(sctx->left_path->nodes[0],
				left_ii);
	} else {
		right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
				sctx->right_path->slots[0],
				struct btrfs_inode_item);
		right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
				right_ii);
	}
	if (result == BTRFS_COMPARE_TREE_CHANGED) {
		right_ii = btrfs_item_ptr(sctx->right_path->nodes[0],
				sctx->right_path->slots[0],
				struct btrfs_inode_item);

		right_gen = btrfs_inode_generation(sctx->right_path->nodes[0],
				right_ii);
5069 5070 5071 5072 5073 5074 5075 5076

		/*
		 * The cur_ino = root dir case is special here. We can't treat
		 * the inode as deleted+reused because it would generate a
		 * stream that tries to delete/mkdir the root dir.
		 */
		if (left_gen != right_gen &&
		    sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087
			sctx->cur_inode_new_gen = 1;
	}

	if (result == BTRFS_COMPARE_TREE_NEW) {
		sctx->cur_inode_gen = left_gen;
		sctx->cur_inode_new = 1;
		sctx->cur_inode_deleted = 0;
		sctx->cur_inode_size = btrfs_inode_size(
				sctx->left_path->nodes[0], left_ii);
		sctx->cur_inode_mode = btrfs_inode_mode(
				sctx->left_path->nodes[0], left_ii);
L
Liu Bo 已提交
5088 5089
		sctx->cur_inode_rdev = btrfs_inode_rdev(
				sctx->left_path->nodes[0], left_ii);
5090
		if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5091
			ret = send_create_inode_if_needed(sctx);
5092 5093 5094 5095 5096 5097 5098 5099 5100
	} else if (result == BTRFS_COMPARE_TREE_DELETED) {
		sctx->cur_inode_gen = right_gen;
		sctx->cur_inode_new = 0;
		sctx->cur_inode_deleted = 1;
		sctx->cur_inode_size = btrfs_inode_size(
				sctx->right_path->nodes[0], right_ii);
		sctx->cur_inode_mode = btrfs_inode_mode(
				sctx->right_path->nodes[0], right_ii);
	} else if (result == BTRFS_COMPARE_TREE_CHANGED) {
5101 5102 5103 5104 5105 5106 5107
		/*
		 * We need to do some special handling in case the inode was
		 * reported as changed with a changed generation number. This
		 * means that the original inode was deleted and new inode
		 * reused the same inum. So we have to treat the old inode as
		 * deleted and the new one as new.
		 */
5108
		if (sctx->cur_inode_new_gen) {
5109 5110 5111
			/*
			 * First, process the inode as if it was deleted.
			 */
5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123
			sctx->cur_inode_gen = right_gen;
			sctx->cur_inode_new = 0;
			sctx->cur_inode_deleted = 1;
			sctx->cur_inode_size = btrfs_inode_size(
					sctx->right_path->nodes[0], right_ii);
			sctx->cur_inode_mode = btrfs_inode_mode(
					sctx->right_path->nodes[0], right_ii);
			ret = process_all_refs(sctx,
					BTRFS_COMPARE_TREE_DELETED);
			if (ret < 0)
				goto out;

5124 5125 5126
			/*
			 * Now process the inode as if it was new.
			 */
5127 5128 5129 5130 5131 5132 5133
			sctx->cur_inode_gen = left_gen;
			sctx->cur_inode_new = 1;
			sctx->cur_inode_deleted = 0;
			sctx->cur_inode_size = btrfs_inode_size(
					sctx->left_path->nodes[0], left_ii);
			sctx->cur_inode_mode = btrfs_inode_mode(
					sctx->left_path->nodes[0], left_ii);
L
Liu Bo 已提交
5134 5135
			sctx->cur_inode_rdev = btrfs_inode_rdev(
					sctx->left_path->nodes[0], left_ii);
5136
			ret = send_create_inode_if_needed(sctx);
5137 5138 5139 5140 5141 5142
			if (ret < 0)
				goto out;

			ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
			if (ret < 0)
				goto out;
5143 5144 5145 5146 5147
			/*
			 * Advance send_progress now as we did not get into
			 * process_recorded_refs_if_needed in the new_gen case.
			 */
			sctx->send_progress = sctx->cur_ino + 1;
5148 5149 5150 5151 5152

			/*
			 * Now process all extents and xattrs of the inode as if
			 * they were all new.
			 */
5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174
			ret = process_all_extents(sctx);
			if (ret < 0)
				goto out;
			ret = process_all_new_xattrs(sctx);
			if (ret < 0)
				goto out;
		} else {
			sctx->cur_inode_gen = left_gen;
			sctx->cur_inode_new = 0;
			sctx->cur_inode_new_gen = 0;
			sctx->cur_inode_deleted = 0;
			sctx->cur_inode_size = btrfs_inode_size(
					sctx->left_path->nodes[0], left_ii);
			sctx->cur_inode_mode = btrfs_inode_mode(
					sctx->left_path->nodes[0], left_ii);
		}
	}

out:
	return ret;
}

5175 5176 5177 5178 5179 5180 5181 5182 5183 5184
/*
 * We have to process new refs before deleted refs, but compare_trees gives us
 * the new and deleted refs mixed. To fix this, we record the new/deleted refs
 * first and later process them in process_recorded_refs.
 * For the cur_inode_new_gen case, we skip recording completely because
 * changed_inode did already initiate processing of refs. The reason for this is
 * that in this case, compare_tree actually compares the refs of 2 different
 * inodes. To fix this, process_all_refs is used in changed_inode to handle all
 * refs of the right tree as deleted and all refs of the left tree as new.
 */
5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201 5202 5203 5204
static int changed_ref(struct send_ctx *sctx,
		       enum btrfs_compare_tree_result result)
{
	int ret = 0;

	BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);

	if (!sctx->cur_inode_new_gen &&
	    sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID) {
		if (result == BTRFS_COMPARE_TREE_NEW)
			ret = record_new_ref(sctx);
		else if (result == BTRFS_COMPARE_TREE_DELETED)
			ret = record_deleted_ref(sctx);
		else if (result == BTRFS_COMPARE_TREE_CHANGED)
			ret = record_changed_ref(sctx);
	}

	return ret;
}

5205 5206 5207 5208 5209
/*
 * Process new/deleted/changed xattrs. We skip processing in the
 * cur_inode_new_gen case because changed_inode did already initiate processing
 * of xattrs. The reason is the same as in changed_ref
 */
5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228
static int changed_xattr(struct send_ctx *sctx,
			 enum btrfs_compare_tree_result result)
{
	int ret = 0;

	BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);

	if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
		if (result == BTRFS_COMPARE_TREE_NEW)
			ret = process_new_xattr(sctx);
		else if (result == BTRFS_COMPARE_TREE_DELETED)
			ret = process_deleted_xattr(sctx);
		else if (result == BTRFS_COMPARE_TREE_CHANGED)
			ret = process_changed_xattr(sctx);
	}

	return ret;
}

5229 5230 5231 5232 5233
/*
 * Process new/deleted/changed extents. We skip processing in the
 * cur_inode_new_gen case because changed_inode did already initiate processing
 * of extents. The reason is the same as in changed_ref
 */
5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249
static int changed_extent(struct send_ctx *sctx,
			  enum btrfs_compare_tree_result result)
{
	int ret = 0;

	BUG_ON(sctx->cur_ino != sctx->cmp_key->objectid);

	if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) {
		if (result != BTRFS_COMPARE_TREE_DELETED)
			ret = process_extent(sctx, sctx->left_path,
					sctx->cmp_key);
	}

	return ret;
}

5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262 5263 5264 5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307
static int dir_changed(struct send_ctx *sctx, u64 dir)
{
	u64 orig_gen, new_gen;
	int ret;

	ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
			     NULL, NULL);
	if (ret)
		return ret;

	ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
			     NULL, NULL, NULL);
	if (ret)
		return ret;

	return (orig_gen != new_gen) ? 1 : 0;
}

static int compare_refs(struct send_ctx *sctx, struct btrfs_path *path,
			struct btrfs_key *key)
{
	struct btrfs_inode_extref *extref;
	struct extent_buffer *leaf;
	u64 dirid = 0, last_dirid = 0;
	unsigned long ptr;
	u32 item_size;
	u32 cur_offset = 0;
	int ref_name_len;
	int ret = 0;

	/* Easy case, just check this one dirid */
	if (key->type == BTRFS_INODE_REF_KEY) {
		dirid = key->offset;

		ret = dir_changed(sctx, dirid);
		goto out;
	}

	leaf = path->nodes[0];
	item_size = btrfs_item_size_nr(leaf, path->slots[0]);
	ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
	while (cur_offset < item_size) {
		extref = (struct btrfs_inode_extref *)(ptr +
						       cur_offset);
		dirid = btrfs_inode_extref_parent(leaf, extref);
		ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
		cur_offset += ref_name_len + sizeof(*extref);
		if (dirid == last_dirid)
			continue;
		ret = dir_changed(sctx, dirid);
		if (ret)
			break;
		last_dirid = dirid;
	}
out:
	return ret;
}

5308 5309 5310 5311
/*
 * Updates compare related fields in sctx and simply forwards to the actual
 * changed_xxx functions.
 */
5312 5313 5314 5315 5316 5317 5318 5319 5320 5321 5322
static int changed_cb(struct btrfs_root *left_root,
		      struct btrfs_root *right_root,
		      struct btrfs_path *left_path,
		      struct btrfs_path *right_path,
		      struct btrfs_key *key,
		      enum btrfs_compare_tree_result result,
		      void *ctx)
{
	int ret = 0;
	struct send_ctx *sctx = ctx;

5323
	if (result == BTRFS_COMPARE_TREE_SAME) {
5324 5325 5326 5327 5328 5329 5330 5331 5332 5333
		if (key->type == BTRFS_INODE_REF_KEY ||
		    key->type == BTRFS_INODE_EXTREF_KEY) {
			ret = compare_refs(sctx, left_path, key);
			if (!ret)
				return 0;
			if (ret < 0)
				return ret;
		} else if (key->type == BTRFS_EXTENT_DATA_KEY) {
			return maybe_send_hole(sctx, left_path, key);
		} else {
5334
			return 0;
5335
		}
5336 5337 5338 5339
		result = BTRFS_COMPARE_TREE_CHANGED;
		ret = 0;
	}

5340 5341 5342 5343 5344 5345 5346 5347
	sctx->left_path = left_path;
	sctx->right_path = right_path;
	sctx->cmp_key = key;

	ret = finish_inode_if_needed(sctx, 0);
	if (ret < 0)
		goto out;

5348 5349 5350 5351 5352
	/* Ignore non-FS objects */
	if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
	    key->objectid == BTRFS_FREE_SPACE_OBJECTID)
		goto out;

5353 5354
	if (key->type == BTRFS_INODE_ITEM_KEY)
		ret = changed_inode(sctx, result);
5355 5356
	else if (key->type == BTRFS_INODE_REF_KEY ||
		 key->type == BTRFS_INODE_EXTREF_KEY)
5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369
		ret = changed_ref(sctx, result);
	else if (key->type == BTRFS_XATTR_ITEM_KEY)
		ret = changed_xattr(sctx, result);
	else if (key->type == BTRFS_EXTENT_DATA_KEY)
		ret = changed_extent(sctx, result);

out:
	return ret;
}

static int full_send_tree(struct send_ctx *sctx)
{
	int ret;
5370
	struct btrfs_trans_handle *trans = NULL;
5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382 5383
	struct btrfs_root *send_root = sctx->send_root;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_path *path;
	struct extent_buffer *eb;
	int slot;
	u64 start_ctransid;
	u64 ctransid;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

5384
	spin_lock(&send_root->root_item_lock);
5385
	start_ctransid = btrfs_root_ctransid(&send_root->root_item);
5386
	spin_unlock(&send_root->root_item_lock);
5387 5388 5389 5390 5391

	key.objectid = BTRFS_FIRST_FREE_OBJECTID;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;

5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404
join_trans:
	/*
	 * We need to make sure the transaction does not get committed
	 * while we do anything on commit roots. Join a transaction to prevent
	 * this.
	 */
	trans = btrfs_join_transaction(send_root);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		trans = NULL;
		goto out;
	}

5405
	/*
5406 5407
	 * Make sure the tree has not changed after re-joining. We detect this
	 * by comparing start_ctransid and ctransid. They should always match.
5408
	 */
5409
	spin_lock(&send_root->root_item_lock);
5410
	ctransid = btrfs_root_ctransid(&send_root->root_item);
5411
	spin_unlock(&send_root->root_item_lock);
5412 5413

	if (ctransid != start_ctransid) {
5414
		WARN(1, KERN_WARNING "BTRFS: the root that you're trying to "
5415 5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426 5427
				     "send was modified in between. This is "
				     "probably a bug.\n");
		ret = -EIO;
		goto out;
	}

	ret = btrfs_search_slot_for_read(send_root, &key, path, 1, 0);
	if (ret < 0)
		goto out;
	if (ret)
		goto out_finish;

	while (1) {
5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440
		/*
		 * When someone want to commit while we iterate, end the
		 * joined transaction and rejoin.
		 */
		if (btrfs_should_end_transaction(trans, send_root)) {
			ret = btrfs_end_transaction(trans, send_root);
			trans = NULL;
			if (ret < 0)
				goto out;
			btrfs_release_path(path);
			goto join_trans;
		}

5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467
		eb = path->nodes[0];
		slot = path->slots[0];
		btrfs_item_key_to_cpu(eb, &found_key, slot);

		ret = changed_cb(send_root, NULL, path, NULL,
				&found_key, BTRFS_COMPARE_TREE_NEW, sctx);
		if (ret < 0)
			goto out;

		key.objectid = found_key.objectid;
		key.type = found_key.type;
		key.offset = found_key.offset + 1;

		ret = btrfs_next_item(send_root, path);
		if (ret < 0)
			goto out;
		if (ret) {
			ret  = 0;
			break;
		}
	}

out_finish:
	ret = finish_inode_if_needed(sctx, 1);

out:
	btrfs_free_path(path);
5468 5469 5470 5471 5472 5473
	if (trans) {
		if (!ret)
			ret = btrfs_end_transaction(trans, send_root);
		else
			btrfs_end_transaction(trans, send_root);
	}
5474 5475 5476 5477 5478 5479 5480
	return ret;
}

static int send_subvol(struct send_ctx *sctx)
{
	int ret;

5481 5482 5483 5484 5485
	if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
		ret = send_header(sctx);
		if (ret < 0)
			goto out;
	}
5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505 5506 5507 5508 5509

	ret = send_subvol_begin(sctx);
	if (ret < 0)
		goto out;

	if (sctx->parent_root) {
		ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
				changed_cb, sctx);
		if (ret < 0)
			goto out;
		ret = finish_inode_if_needed(sctx, 1);
		if (ret < 0)
			goto out;
	} else {
		ret = full_send_tree(sctx);
		if (ret < 0)
			goto out;
	}

out:
	free_recorded_refs(sctx);
	return ret;
}

5510 5511 5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524
static void btrfs_root_dec_send_in_progress(struct btrfs_root* root)
{
	spin_lock(&root->root_item_lock);
	root->send_in_progress--;
	/*
	 * Not much left to do, we don't know why it's unbalanced and
	 * can't blindly reset it to 0.
	 */
	if (root->send_in_progress < 0)
		btrfs_err(root->fs_info,
			"send_in_progres unbalanced %d root %llu\n",
			root->send_in_progress, root->root_key.objectid);
	spin_unlock(&root->root_item_lock);
}

5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535
long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
{
	int ret = 0;
	struct btrfs_root *send_root;
	struct btrfs_root *clone_root;
	struct btrfs_fs_info *fs_info;
	struct btrfs_ioctl_send_args *arg = NULL;
	struct btrfs_key key;
	struct send_ctx *sctx = NULL;
	u32 i;
	u64 *clone_sources_tmp = NULL;
5536
	int clone_sources_to_rollback = 0;
5537
	int sort_clone_roots = 0;
5538
	int index;
5539 5540 5541 5542

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

A
Al Viro 已提交
5543
	send_root = BTRFS_I(file_inode(mnt_file))->root;
5544 5545
	fs_info = send_root->fs_info;

5546 5547 5548 5549 5550 5551 5552 5553
	/*
	 * The subvolume must remain read-only during send, protect against
	 * making it RW.
	 */
	spin_lock(&send_root->root_item_lock);
	send_root->send_in_progress++;
	spin_unlock(&send_root->root_item_lock);

J
Josef Bacik 已提交
5554 5555 5556 5557 5558 5559
	/*
	 * This is done when we lookup the root, it should already be complete
	 * by the time we get here.
	 */
	WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE);

5560 5561 5562 5563 5564 5565 5566 5567 5568
	/*
	 * Userspace tools do the checks and warn the user if it's
	 * not RO.
	 */
	if (!btrfs_root_readonly(send_root)) {
		ret = -EPERM;
		goto out;
	}

5569 5570 5571 5572 5573 5574 5575 5576
	arg = memdup_user(arg_, sizeof(*arg));
	if (IS_ERR(arg)) {
		ret = PTR_ERR(arg);
		arg = NULL;
		goto out;
	}

	if (!access_ok(VERIFY_READ, arg->clone_sources,
5577 5578
			sizeof(*arg->clone_sources) *
			arg->clone_sources_count)) {
5579 5580 5581 5582
		ret = -EFAULT;
		goto out;
	}

5583
	if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
5584 5585 5586 5587
		ret = -EINVAL;
		goto out;
	}

5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598
	sctx = kzalloc(sizeof(struct send_ctx), GFP_NOFS);
	if (!sctx) {
		ret = -ENOMEM;
		goto out;
	}

	INIT_LIST_HEAD(&sctx->new_refs);
	INIT_LIST_HEAD(&sctx->deleted_refs);
	INIT_RADIX_TREE(&sctx->name_cache, GFP_NOFS);
	INIT_LIST_HEAD(&sctx->name_cache_list);

5599 5600
	sctx->flags = arg->flags;

5601
	sctx->send_filp = fget(arg->send_fd);
5602 5603
	if (!sctx->send_filp) {
		ret = -EBADF;
5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622
		goto out;
	}

	sctx->send_root = send_root;
	sctx->clone_roots_cnt = arg->clone_sources_count;

	sctx->send_max_size = BTRFS_SEND_BUF_SIZE;
	sctx->send_buf = vmalloc(sctx->send_max_size);
	if (!sctx->send_buf) {
		ret = -ENOMEM;
		goto out;
	}

	sctx->read_buf = vmalloc(BTRFS_SEND_READ_SIZE);
	if (!sctx->read_buf) {
		ret = -ENOMEM;
		goto out;
	}

5623 5624
	sctx->pending_dir_moves = RB_ROOT;
	sctx->waiting_dir_moves = RB_ROOT;
5625
	sctx->orphan_dirs = RB_ROOT;
5626

5627 5628 5629 5630 5631 5632 5633 5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653
	sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
			(arg->clone_sources_count + 1));
	if (!sctx->clone_roots) {
		ret = -ENOMEM;
		goto out;
	}

	if (arg->clone_sources_count) {
		clone_sources_tmp = vmalloc(arg->clone_sources_count *
				sizeof(*arg->clone_sources));
		if (!clone_sources_tmp) {
			ret = -ENOMEM;
			goto out;
		}

		ret = copy_from_user(clone_sources_tmp, arg->clone_sources,
				arg->clone_sources_count *
				sizeof(*arg->clone_sources));
		if (ret) {
			ret = -EFAULT;
			goto out;
		}

		for (i = 0; i < arg->clone_sources_count; i++) {
			key.objectid = clone_sources_tmp[i];
			key.type = BTRFS_ROOT_ITEM_KEY;
			key.offset = (u64)-1;
5654 5655 5656

			index = srcu_read_lock(&fs_info->subvol_srcu);

5657 5658
			clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
			if (IS_ERR(clone_root)) {
5659
				srcu_read_unlock(&fs_info->subvol_srcu, index);
5660 5661 5662
				ret = PTR_ERR(clone_root);
				goto out;
			}
5663 5664 5665 5666 5667
			clone_sources_to_rollback = i + 1;
			spin_lock(&clone_root->root_item_lock);
			clone_root->send_in_progress++;
			if (!btrfs_root_readonly(clone_root)) {
				spin_unlock(&clone_root->root_item_lock);
5668
				srcu_read_unlock(&fs_info->subvol_srcu, index);
5669 5670 5671 5672
				ret = -EPERM;
				goto out;
			}
			spin_unlock(&clone_root->root_item_lock);
5673 5674
			srcu_read_unlock(&fs_info->subvol_srcu, index);

5675 5676 5677 5678 5679 5680 5681 5682 5683 5684
			sctx->clone_roots[i].root = clone_root;
		}
		vfree(clone_sources_tmp);
		clone_sources_tmp = NULL;
	}

	if (arg->parent_root) {
		key.objectid = arg->parent_root;
		key.type = BTRFS_ROOT_ITEM_KEY;
		key.offset = (u64)-1;
5685 5686 5687

		index = srcu_read_lock(&fs_info->subvol_srcu);

5688
		sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
5689
		if (IS_ERR(sctx->parent_root)) {
5690
			srcu_read_unlock(&fs_info->subvol_srcu, index);
5691
			ret = PTR_ERR(sctx->parent_root);
5692 5693
			goto out;
		}
5694

5695 5696 5697 5698
		spin_lock(&sctx->parent_root->root_item_lock);
		sctx->parent_root->send_in_progress++;
		if (!btrfs_root_readonly(sctx->parent_root)) {
			spin_unlock(&sctx->parent_root->root_item_lock);
5699
			srcu_read_unlock(&fs_info->subvol_srcu, index);
5700 5701 5702 5703
			ret = -EPERM;
			goto out;
		}
		spin_unlock(&sctx->parent_root->root_item_lock);
5704 5705

		srcu_read_unlock(&fs_info->subvol_srcu, index);
5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718
	}

	/*
	 * Clones from send_root are allowed, but only if the clone source
	 * is behind the current send position. This is checked while searching
	 * for possible clone sources.
	 */
	sctx->clone_roots[sctx->clone_roots_cnt++].root = sctx->send_root;

	/* We do a bsearch later */
	sort(sctx->clone_roots, sctx->clone_roots_cnt,
			sizeof(*sctx->clone_roots), __clone_root_cmp_sort,
			NULL);
5719
	sort_clone_roots = 1;
5720

5721
	current->journal_info = (void *)BTRFS_SEND_TRANS_STUB;
5722
	ret = send_subvol(sctx);
5723
	current->journal_info = NULL;
5724 5725 5726
	if (ret < 0)
		goto out;

5727 5728 5729 5730 5731 5732 5733 5734
	if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_END_CMD)) {
		ret = begin_cmd(sctx, BTRFS_SEND_C_END);
		if (ret < 0)
			goto out;
		ret = send_cmd(sctx);
		if (ret < 0)
			goto out;
	}
5735 5736

out:
5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764
	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->pending_dir_moves));
	while (sctx && !RB_EMPTY_ROOT(&sctx->pending_dir_moves)) {
		struct rb_node *n;
		struct pending_dir_move *pm;

		n = rb_first(&sctx->pending_dir_moves);
		pm = rb_entry(n, struct pending_dir_move, node);
		while (!list_empty(&pm->list)) {
			struct pending_dir_move *pm2;

			pm2 = list_first_entry(&pm->list,
					       struct pending_dir_move, list);
			free_pending_move(sctx, pm2);
		}
		free_pending_move(sctx, pm);
	}

	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves));
	while (sctx && !RB_EMPTY_ROOT(&sctx->waiting_dir_moves)) {
		struct rb_node *n;
		struct waiting_dir_move *dm;

		n = rb_first(&sctx->waiting_dir_moves);
		dm = rb_entry(n, struct waiting_dir_move, node);
		rb_erase(&dm->node, &sctx->waiting_dir_moves);
		kfree(dm);
	}

5765 5766 5767 5768 5769 5770 5771 5772 5773 5774
	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->orphan_dirs));
	while (sctx && !RB_EMPTY_ROOT(&sctx->orphan_dirs)) {
		struct rb_node *n;
		struct orphan_dir_info *odi;

		n = rb_first(&sctx->orphan_dirs);
		odi = rb_entry(n, struct orphan_dir_info, node);
		free_orphan_dir_info(sctx, odi);
	}

5775 5776 5777 5778 5779 5780 5781 5782 5783 5784 5785
	if (sort_clone_roots) {
		for (i = 0; i < sctx->clone_roots_cnt; i++)
			btrfs_root_dec_send_in_progress(
					sctx->clone_roots[i].root);
	} else {
		for (i = 0; sctx && i < clone_sources_to_rollback; i++)
			btrfs_root_dec_send_in_progress(
					sctx->clone_roots[i].root);

		btrfs_root_dec_send_in_progress(send_root);
	}
5786 5787
	if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
		btrfs_root_dec_send_in_progress(sctx->parent_root);
5788

5789 5790 5791 5792 5793 5794 5795 5796 5797 5798 5799 5800 5801 5802 5803 5804 5805 5806
	kfree(arg);
	vfree(clone_sources_tmp);

	if (sctx) {
		if (sctx->send_filp)
			fput(sctx->send_filp);

		vfree(sctx->clone_roots);
		vfree(sctx->send_buf);
		vfree(sctx->read_buf);

		name_cache_free(sctx);

		kfree(sctx);
	}

	return ret;
}