send.c 132.3 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;
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	path->need_commit_sem = 1;
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	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.
 */
775 776 777
static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
			  u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid,
			  u64 *gid, u64 *rdev)
778 779 780 781 782 783 784 785 786 787
{
	int ret;
	struct btrfs_inode_item *ii;
	struct btrfs_key key;

	key.objectid = ino;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret) {
788 789 790
		if (ret > 0)
			ret = -ENOENT;
		return ret;
791 792 793 794 795 796 797 798 799 800 801 802 803 804
	}

	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);
805 806
	if (rdev)
		*rdev = btrfs_inode_rdev(path->nodes[0], ii);
807

808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823
	return ret;
}

static int get_inode_info(struct btrfs_root *root,
			  u64 ino, u64 *size, u64 *gen,
			  u64 *mode, u64 *uid, u64 *gid,
			  u64 *rdev)
{
	struct btrfs_path *path;
	int ret;

	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;
	ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid,
			       rdev);
824 825 826 827 828 829 830 831 832
	btrfs_free_path(path);
	return ret;
}

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

/*
833 834
 * Helper function to iterate the entries in ONE btrfs_inode_ref or
 * btrfs_inode_extref.
835 836 837
 * 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.
 *
838
 * path must point to the INODE_REF or INODE_EXTREF when called.
839
 */
840
static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path,
841 842 843
			     struct btrfs_key *found_key, int resolve,
			     iterate_inode_ref_t iterate, void *ctx)
{
844
	struct extent_buffer *eb = path->nodes[0];
845 846
	struct btrfs_item *item;
	struct btrfs_inode_ref *iref;
847
	struct btrfs_inode_extref *extref;
848 849
	struct btrfs_path *tmp_path;
	struct fs_path *p;
850
	u32 cur = 0;
851
	u32 total;
852
	int slot = path->slots[0];
853 854 855
	u32 name_len;
	char *start;
	int ret = 0;
856
	int num = 0;
857
	int index;
858 859 860 861
	u64 dir;
	unsigned long name_off;
	unsigned long elem_size;
	unsigned long ptr;
862

863
	p = fs_path_alloc_reversed();
864 865 866 867 868
	if (!p)
		return -ENOMEM;

	tmp_path = alloc_path_for_send();
	if (!tmp_path) {
869
		fs_path_free(p);
870 871 872 873
		return -ENOMEM;
	}


874 875 876
	if (found_key->type == BTRFS_INODE_REF_KEY) {
		ptr = (unsigned long)btrfs_item_ptr(eb, slot,
						    struct btrfs_inode_ref);
877
		item = btrfs_item_nr(slot);
878 879 880 881 882 883 884 885
		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);
	}

886 887 888
	while (cur < total) {
		fs_path_reset(p);

889 890 891 892 893 894 895 896 897 898 899 900 901 902
		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);
		}

903
		if (resolve) {
904 905 906
			start = btrfs_ref_to_path(root, tmp_path, name_len,
						  name_off, eb, dir,
						  p->buf, p->buf_len);
907 908 909 910 911 912 913 914 915 916
			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;
917 918 919 920
				start = btrfs_ref_to_path(root, tmp_path,
							  name_len, name_off,
							  eb, dir,
							  p->buf, p->buf_len);
921 922 923 924 925 926 927 928
				if (IS_ERR(start)) {
					ret = PTR_ERR(start);
					goto out;
				}
				BUG_ON(start < p->buf);
			}
			p->start = start;
		} else {
929 930
			ret = fs_path_add_from_extent_buffer(p, eb, name_off,
							     name_len);
931 932 933 934
			if (ret < 0)
				goto out;
		}

935 936
		cur += elem_size + name_len;
		ret = iterate(num, dir, index, p, ctx);
937 938 939 940 941 942 943
		if (ret)
			goto out;
		num++;
	}

out:
	btrfs_free_path(tmp_path);
944
	fs_path_free(p);
945 946 947 948 949 950 951 952 953 954 955 956 957 958 959
	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.
 */
960
static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
961 962 963 964 965 966 967 968 969
			    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;
970
	const int buf_len = PATH_MAX;
971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987
	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];
988
	item = btrfs_item_nr(slot);
989 990 991 992 993 994 995 996 997 998 999 1000
	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);

1001 1002 1003
		/*
		 * Path too long
		 */
1004
		if (name_len + data_len > buf_len) {
1005 1006
			ret = -ENAMETOOLONG;
			goto out;
1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
		}

		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:
1029
	kfree(buf);
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
	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.
 */
1051
static int get_inode_path(struct btrfs_root *root,
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076
			  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 ||
1077 1078
	    (found_key.type != BTRFS_INODE_REF_KEY &&
	     found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1079 1080 1081 1082
		ret = -ENOENT;
		goto out;
	}

1083 1084
	ret = iterate_inode_ref(root, p, &found_key, 1,
				__copy_first_ref, path);
1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096
	if (ret < 0)
		goto out;
	ret = 0;

out:
	btrfs_free_path(p);
	return ret;
}

struct backref_ctx {
	struct send_ctx *sctx;

1097
	struct btrfs_path *path;
1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
	/* 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 */
1112
	int found_itself;
1113 1114 1115 1116
};

static int __clone_root_cmp_bsearch(const void *key, const void *elt)
{
1117
	u64 root = (u64)(uintptr_t)key;
1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140
	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.
1141
 * Results are collected in sctx->clone_roots->ino/offset/found_refs
1142 1143 1144 1145 1146 1147 1148 1149 1150
 */
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 */
1151
	found = bsearch((void *)(uintptr_t)root, bctx->sctx->clone_roots,
1152 1153 1154 1155 1156 1157 1158 1159 1160
			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) {
1161
		bctx->found_itself = 1;
1162 1163 1164
	}

	/*
1165
	 * There are inodes that have extents that lie behind its i_size. Don't
1166 1167
	 * accept clones from these extents.
	 */
1168 1169 1170
	ret = __get_inode_info(found->root, bctx->path, ino, &i_size, NULL, NULL,
			       NULL, NULL, NULL);
	btrfs_release_path(bctx->path);
1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189
	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;
1190 1191 1192 1193
#if 0
		if (ino > bctx->cur_objectid)
			return 0;
		if (offset + bctx->extent_len > bctx->cur_offset)
1194
			return 0;
1195
#endif
1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214
	}

	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;
}

/*
1215 1216 1217 1218 1219 1220
 * 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.
 *
1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231
 * 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;
1232
	u64 disk_byte;
1233 1234
	u64 num_bytes;
	u64 extent_item_pos;
1235
	u64 flags = 0;
1236 1237
	struct btrfs_file_extent_item *fi;
	struct extent_buffer *eb = path->nodes[0];
1238
	struct backref_ctx *backref_ctx = NULL;
1239 1240 1241
	struct clone_root *cur_clone_root;
	struct btrfs_key found_key;
	struct btrfs_path *tmp_path;
1242
	int compressed;
1243 1244 1245 1246 1247 1248
	u32 i;

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

1249 1250 1251
	/* We only use this path under the commit sem */
	tmp_path->need_commit_sem = 0;

1252 1253 1254 1255 1256 1257
	backref_ctx = kmalloc(sizeof(*backref_ctx), GFP_NOFS);
	if (!backref_ctx) {
		ret = -ENOMEM;
		goto out;
	}

1258 1259
	backref_ctx->path = tmp_path;

1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276
	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;
	}
1277
	compressed = btrfs_file_extent_compression(eb, fi);
1278 1279

	num_bytes = btrfs_file_extent_num_bytes(eb, fi);
1280 1281
	disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
	if (disk_byte == 0) {
1282 1283 1284
		ret = -ENOENT;
		goto out;
	}
1285
	logical = disk_byte + btrfs_file_extent_offset(eb, fi);
1286

1287
	down_read(&sctx->send_root->fs_info->commit_root_sem);
1288 1289
	ret = extent_from_logical(sctx->send_root->fs_info, disk_byte, tmp_path,
				  &found_key, &flags);
1290
	up_read(&sctx->send_root->fs_info->commit_root_sem);
1291 1292 1293 1294
	btrfs_release_path(tmp_path);

	if (ret < 0)
		goto out;
1295
	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309
		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;
	}

1310 1311 1312 1313 1314 1315
	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;
1316 1317 1318 1319 1320 1321 1322

	/*
	 * 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)
1323
		backref_ctx->extent_len = ino_size - data_offset;
1324 1325 1326 1327

	/*
	 * Now collect all backrefs.
	 */
1328 1329 1330 1331
	if (compressed == BTRFS_COMPRESS_NONE)
		extent_item_pos = logical - found_key.objectid;
	else
		extent_item_pos = 0;
1332 1333
	ret = iterate_extent_inodes(sctx->send_root->fs_info,
					found_key.objectid, extent_item_pos, 1,
1334
					__iterate_backrefs, backref_ctx);
1335

1336 1337 1338
	if (ret < 0)
		goto out;

1339
	if (!backref_ctx->found_itself) {
1340 1341
		/* found a bug in backref code? */
		ret = -EIO;
1342
		btrfs_err(sctx->send_root->fs_info, "did not find backref in "
1343
				"send_root. inode=%llu, offset=%llu, "
1344 1345
				"disk_byte=%llu found extent=%llu\n",
				ino, data_offset, disk_byte, found_key.objectid);
1346 1347 1348 1349 1350 1351 1352 1353
		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);

1354
	if (!backref_ctx->found)
1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369
		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) {
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379
		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);
		}
1380 1381 1382 1383 1384 1385 1386 1387
		*found = cur_clone_root;
		ret = 0;
	} else {
		ret = -ENOENT;
	}

out:
	btrfs_free_path(tmp_path);
1388
	kfree(backref_ctx);
1389 1390 1391
	return ret;
}

1392
static int read_symlink(struct btrfs_root *root,
1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424
			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);
1425
	len = btrfs_file_extent_inline_len(path->nodes[0], path->slots[0], ei);
1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453

	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) {
1454
		len = snprintf(tmp, sizeof(tmp), "o%llu-%llu-%llu",
1455
				ino, gen, idx);
1456
		ASSERT(len < sizeof(tmp));
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 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518

		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,
1519
			NULL, NULL);
1520 1521 1522 1523 1524 1525 1526 1527
	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,
1528
				NULL, NULL, NULL, NULL);
1529 1530 1531 1532 1533 1534
		if (ret < 0 && ret != -ENOENT)
			goto out;
		right_ret = ret;
	}

	if (!left_ret && !right_ret) {
1535
		if (left_gen == gen && right_gen == gen) {
1536
			ret = inode_state_no_change;
1537
		} else if (left_gen == gen) {
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 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630
			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;
}

1631 1632 1633 1634
/*
 * 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.
 */
1635
static int get_first_ref(struct btrfs_root *root, u64 ino,
1636 1637 1638 1639 1640 1641 1642
			 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;
1643
	u64 parent_dir;
1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658

	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]);
1659 1660 1661
	if (ret || found_key.objectid != ino ||
	    (found_key.type != BTRFS_INODE_REF_KEY &&
	     found_key.type != BTRFS_INODE_EXTREF_KEY)) {
1662 1663 1664 1665
		ret = -ENOENT;
		goto out;
	}

1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683
	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);
	}
1684 1685 1686 1687
	if (ret < 0)
		goto out;
	btrfs_release_path(path);

1688
	ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
1689
			NULL, NULL);
1690 1691 1692
	if (ret < 0)
		goto out;

1693
	*dir = parent_dir;
1694 1695 1696 1697 1698 1699

out:
	btrfs_free_path(path);
	return ret;
}

1700
static int is_first_ref(struct btrfs_root *root,
1701 1702 1703 1704 1705 1706 1707 1708
			u64 ino, u64 dir,
			const char *name, int name_len)
{
	int ret;
	struct fs_path *tmp_name;
	u64 tmp_dir;
	u64 tmp_dir_gen;

1709
	tmp_name = fs_path_alloc();
1710 1711 1712
	if (!tmp_name)
		return -ENOMEM;

1713
	ret = get_first_ref(root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
1714 1715 1716
	if (ret < 0)
		goto out;

1717
	if (dir != tmp_dir || name_len != fs_path_len(tmp_name)) {
1718 1719 1720 1721
		ret = 0;
		goto out;
	}

1722
	ret = !memcmp(tmp_name->start, name, name_len);
1723 1724

out:
1725
	fs_path_free(tmp_name);
1726 1727 1728
	return ret;
}

1729 1730 1731 1732 1733 1734 1735 1736 1737 1738
/*
 * 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.
 */
1739 1740 1741 1742 1743
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;
1744
	u64 gen;
1745 1746 1747 1748 1749 1750 1751 1752 1753 1754
	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;

1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772
	/*
	 * 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;
	}

1773 1774 1775 1776 1777 1778 1779 1780 1781
	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;
	}

1782 1783 1784 1785 1786
	/*
	 * 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.
	 */
1787 1788
	if (other_inode > sctx->send_progress) {
		ret = get_inode_info(sctx->parent_root, other_inode, NULL,
1789
				who_gen, NULL, NULL, NULL, NULL);
1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802
		if (ret < 0)
			goto out;

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

out:
	return ret;
}

1803 1804 1805 1806 1807 1808 1809
/*
 * 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.
 */
1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838
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,
1839
			NULL, NULL);
1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857
	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;
}

1858 1859 1860 1861 1862
/*
 * 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.
 */
1863 1864 1865 1866 1867 1868 1869 1870 1871 1872
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;

1873
	name = fs_path_alloc();
1874 1875 1876
	if (!name)
		return -ENOMEM;

1877
	ret = get_first_ref(sctx->parent_root, ino, &dir, &dir_gen, name);
1878 1879 1880 1881 1882 1883 1884
	if (ret < 0)
		goto out;

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

out:
1885
	fs_path_free(name);
1886 1887 1888
	return ret;
}

1889 1890 1891 1892
/*
 * 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.
1893
 * In case of error, nce is kfreed.
1894
 */
1895 1896 1897 1898
static int name_cache_insert(struct send_ctx *sctx,
			     struct name_cache_entry *nce)
{
	int ret = 0;
1899 1900 1901 1902 1903 1904
	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);
1905 1906
		if (!nce_head) {
			kfree(nce);
1907
			return -ENOMEM;
1908
		}
1909
		INIT_LIST_HEAD(nce_head);
1910

1911
		ret = radix_tree_insert(&sctx->name_cache, nce->ino, nce_head);
1912 1913 1914
		if (ret < 0) {
			kfree(nce_head);
			kfree(nce);
1915
			return ret;
1916
		}
1917
	}
1918
	list_add_tail(&nce->radix_list, nce_head);
1919 1920 1921 1922 1923 1924 1925 1926 1927
	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)
{
1928
	struct list_head *nce_head;
1929

1930 1931
	nce_head = radix_tree_lookup(&sctx->name_cache,
			(unsigned long)nce->ino);
1932 1933 1934 1935 1936
	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);
	}
1937

1938
	list_del(&nce->radix_list);
1939 1940
	list_del(&nce->list);
	sctx->name_cache_size--;
1941

1942 1943 1944 1945
	/*
	 * We may not get to the final release of nce_head if the lookup fails
	 */
	if (nce_head && list_empty(nce_head)) {
1946 1947 1948
		radix_tree_delete(&sctx->name_cache, (unsigned long)nce->ino);
		kfree(nce_head);
	}
1949 1950 1951 1952 1953
}

static struct name_cache_entry *name_cache_search(struct send_ctx *sctx,
						    u64 ino, u64 gen)
{
1954 1955
	struct list_head *nce_head;
	struct name_cache_entry *cur;
1956

1957 1958
	nce_head = radix_tree_lookup(&sctx->name_cache, (unsigned long)ino);
	if (!nce_head)
1959 1960
		return NULL;

1961 1962 1963 1964
	list_for_each_entry(cur, nce_head, radix_list) {
		if (cur->ino == ino && cur->gen == gen)
			return cur;
	}
1965 1966 1967
	return NULL;
}

1968 1969 1970 1971
/*
 * 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.
 */
1972 1973 1974 1975 1976 1977
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);
}

1978 1979 1980
/*
 * Remove some entries from the beginning of name_cache_list.
 */
1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
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;

2000 2001 2002
	while (!list_empty(&sctx->name_cache_list)) {
		nce = list_entry(sctx->name_cache_list.next,
				struct name_cache_entry, list);
2003
		name_cache_delete(sctx, nce);
2004
		kfree(nce);
2005 2006 2007
	}
}

2008 2009 2010 2011 2012 2013 2014 2015
/*
 * 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.
 */
2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026
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;

2027 2028 2029 2030 2031
	/*
	 * 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.
	 */
2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053
	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;

2054 2055 2056 2057 2058
	/*
	 * 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
	 */
2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070
	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;
	}

2071 2072 2073 2074
	/*
	 * Depending on whether the inode was already processed or not, use
	 * send_root or parent_root for ref lookup.
	 */
2075
	if (ino < sctx->send_progress)
2076 2077
		ret = get_first_ref(sctx->send_root, ino,
				    parent_ino, parent_gen, dest);
2078
	else
2079 2080
		ret = get_first_ref(sctx->parent_root, ino,
				    parent_ino, parent_gen, dest);
2081 2082 2083
	if (ret < 0)
		goto out;

2084 2085 2086 2087
	/*
	 * Check if the ref was overwritten by an inode's ref that was processed
	 * earlier. If yes, treat as orphan and return 1.
	 */
2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100
	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:
2101 2102 2103
	/*
	 * Store the result of the lookup in the name cache.
	 */
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 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166
	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;

2167
	name = fs_path_alloc();
2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178
	if (!name) {
		ret = -ENOMEM;
		goto out;
	}

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

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

2179 2180 2181 2182 2183 2184 2185 2186
		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;
		}

2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197
		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;
		}

2198 2199
		if (ret < 0)
			goto out;
2200

2201 2202 2203 2204 2205 2206 2207 2208 2209
		ret = fs_path_add_path(dest, name);
		if (ret < 0)
			goto out;

		ino = parent_inode;
		gen = parent_gen;
	}

out:
2210
	fs_path_free(name);
2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230
	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;

2231
	path = btrfs_alloc_path();
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 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279
	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,
2280
		    le64_to_cpu(sctx->send_root->root_item.ctransid));
2281 2282 2283 2284
	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,
2285
			    le64_to_cpu(sctx->parent_root->root_item.ctransid));
2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303
	}

	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);

2304
	p = fs_path_alloc();
2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321
	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:
2322
	fs_path_free(p);
2323 2324 2325 2326 2327 2328 2329 2330 2331 2332
	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);

2333
	p = fs_path_alloc();
2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350
	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:
2351
	fs_path_free(p);
2352 2353 2354 2355 2356 2357 2358 2359 2360 2361
	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);

2362
	p = fs_path_alloc();
2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380
	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:
2381
	fs_path_free(p);
2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396
	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);

2397
	p = fs_path_alloc();
2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431
	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));
2432
	/* TODO Add otime support when the otime patches get into upstream */
2433 2434 2435 2436 2437

	ret = send_cmd(sctx);

tlv_put_failure:
out:
2438
	fs_path_free(p);
2439 2440 2441 2442 2443 2444 2445 2446 2447
	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.
 */
2448
static int send_create_inode(struct send_ctx *sctx, u64 ino)
2449 2450 2451 2452
{
	int ret = 0;
	struct fs_path *p;
	int cmd;
2453
	u64 gen;
2454
	u64 mode;
2455
	u64 rdev;
2456

2457
verbose_printk("btrfs: send_create_inode %llu\n", ino);
2458

2459
	p = fs_path_alloc();
2460 2461 2462
	if (!p)
		return -ENOMEM;

L
Liu Bo 已提交
2463 2464 2465 2466 2467 2468 2469 2470 2471 2472
	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;
	}
2473

2474
	if (S_ISREG(mode)) {
2475
		cmd = BTRFS_SEND_C_MKFILE;
2476
	} else if (S_ISDIR(mode)) {
2477
		cmd = BTRFS_SEND_C_MKDIR;
2478
	} else if (S_ISLNK(mode)) {
2479
		cmd = BTRFS_SEND_C_SYMLINK;
2480
	} else if (S_ISCHR(mode) || S_ISBLK(mode)) {
2481
		cmd = BTRFS_SEND_C_MKNOD;
2482
	} else if (S_ISFIFO(mode)) {
2483
		cmd = BTRFS_SEND_C_MKFIFO;
2484
	} else if (S_ISSOCK(mode)) {
2485
		cmd = BTRFS_SEND_C_MKSOCK;
2486
	} else {
2487 2488 2489 2490 2491 2492 2493 2494 2495 2496
		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;

2497
	ret = gen_unique_name(sctx, ino, gen, p);
2498 2499 2500 2501
	if (ret < 0)
		goto out;

	TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
2502
	TLV_PUT_U64(sctx, BTRFS_SEND_A_INO, ino);
2503 2504 2505

	if (S_ISLNK(mode)) {
		fs_path_reset(p);
2506
		ret = read_symlink(sctx->send_root, ino, p);
2507 2508 2509 2510 2511
		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)) {
2512 2513
		TLV_PUT_U64(sctx, BTRFS_SEND_A_RDEV, new_encode_dev(rdev));
		TLV_PUT_U64(sctx, BTRFS_SEND_A_MODE, mode);
2514 2515 2516 2517 2518 2519 2520 2521 2522
	}

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


tlv_put_failure:
out:
2523
	fs_path_free(p);
2524 2525 2526
	return ret;
}

2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551
/*
 * 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;
2552 2553 2554 2555
	ret = btrfs_search_slot(NULL, sctx->send_root, &key, path, 0, 0);
	if (ret < 0)
		goto out;

2556
	while (1) {
2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567
		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;
2568
		}
2569 2570 2571

		btrfs_item_key_to_cpu(eb, &found_key, slot);
		if (found_key.objectid != key.objectid ||
2572 2573 2574 2575 2576 2577 2578 2579
		    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);

2580 2581
		if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
		    di_key.objectid < sctx->send_progress) {
2582 2583 2584 2585
			ret = 1;
			goto out;
		}

2586
		path->slots[0]++;
2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621
	}

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;
}

2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637
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.
 */
2638
static int __record_ref(struct list_head *head, u64 dir,
2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650
		      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
2651 2652 2653 2654
	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)
2655
		ref->dir_path_len = 0;
A
Andy Shevchenko 已提交
2656
	else
2657 2658 2659 2660 2661 2662 2663
		ref->dir_path_len = ref->full_path->end -
				ref->full_path->start - 1 - ref->name_len;

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

2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679
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;
}

2680
static void __free_recorded_refs(struct list_head *head)
2681 2682 2683
{
	struct recorded_ref *cur;

2684 2685
	while (!list_empty(head)) {
		cur = list_entry(head->next, struct recorded_ref, list);
2686
		fs_path_free(cur->full_path);
2687
		list_del(&cur->list);
2688 2689 2690 2691 2692 2693
		kfree(cur);
	}
}

static void free_recorded_refs(struct send_ctx *sctx)
{
2694 2695
	__free_recorded_refs(&sctx->new_refs);
	__free_recorded_refs(&sctx->deleted_refs);
2696 2697 2698
}

/*
2699
 * Renames/moves a file/dir to its orphan name. Used when the first
2700 2701 2702 2703 2704 2705 2706 2707 2708
 * 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;

2709
	orphan = fs_path_alloc();
2710 2711 2712 2713 2714 2715 2716 2717 2718 2719
	if (!orphan)
		return -ENOMEM;

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

	ret = send_rename(sctx, path, orphan);

out:
2720
	fs_path_free(orphan);
2721 2722 2723
	return ret;
}

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 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788
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);
}

2789 2790 2791 2792 2793
/*
 * 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.
 */
2794 2795
static int can_rmdir(struct send_ctx *sctx, u64 dir, u64 dir_gen,
		     u64 send_progress)
2796 2797 2798 2799 2800 2801 2802 2803 2804
{
	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;

2805 2806 2807 2808 2809 2810
	/*
	 * Don't try to rmdir the top/root subvolume dir.
	 */
	if (dir == BTRFS_FIRST_FREE_OBJECTID)
		return 0;

2811 2812 2813 2814 2815 2816 2817
	path = alloc_path_for_send();
	if (!path)
		return -ENOMEM;

	key.objectid = dir;
	key.type = BTRFS_DIR_INDEX_KEY;
	key.offset = 0;
2818 2819 2820
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
2821 2822

	while (1) {
2823 2824
		struct waiting_dir_move *dm;

2825 2826 2827 2828 2829 2830 2831
		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;
2832
		}
2833 2834 2835 2836
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);
		if (found_key.objectid != key.objectid ||
		    found_key.type != key.type)
2837 2838 2839 2840 2841 2842
			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);

2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857
		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;
		}

2858 2859 2860 2861 2862
		if (loc.objectid > send_progress) {
			ret = 0;
			goto out;
		}

2863
		path->slots[0]++;
2864 2865 2866 2867 2868 2869 2870 2871 2872
	}

	ret = 1;

out:
	btrfs_free_path(path);
	return ret;
}

2873 2874
static int is_waiting_for_move(struct send_ctx *sctx, u64 ino)
{
2875
	struct waiting_dir_move *entry = get_waiting_dir_move(sctx, ino);
2876

2877
	return entry != NULL;
2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889
}

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;
2890
	dm->rmdir_ino = 0;
2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909

	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;
}

2910 2911
static struct waiting_dir_move *
get_waiting_dir_move(struct send_ctx *sctx, u64 ino)
2912 2913 2914 2915 2916 2917
{
	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);
2918
		if (ino < entry->ino)
2919
			n = n->rb_left;
2920
		else if (ino > entry->ino)
2921
			n = n->rb_right;
2922 2923
		else
			return entry;
2924
	}
2925 2926 2927 2928 2929 2930 2931 2932 2933 2934
	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);
2935 2936
}

2937 2938 2939 2940
static int add_pending_dir_move(struct send_ctx *sctx,
				u64 ino,
				u64 ino_gen,
				u64 parent_ino)
2941 2942 2943
{
	struct rb_node **p = &sctx->pending_dir_moves.rb_node;
	struct rb_node *parent = NULL;
C
Chris Mason 已提交
2944
	struct pending_dir_move *entry = NULL, *pm;
2945 2946 2947 2948 2949 2950 2951 2952
	struct recorded_ref *cur;
	int exists = 0;
	int ret;

	pm = kmalloc(sizeof(*pm), GFP_NOFS);
	if (!pm)
		return -ENOMEM;
	pm->parent_ino = parent_ino;
2953 2954
	pm->ino = ino;
	pm->gen = ino_gen;
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 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023
	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;
3024
	struct fs_path *name = NULL;
3025 3026
	u64 orig_progress = sctx->send_progress;
	struct recorded_ref *cur;
3027
	u64 parent_ino, parent_gen;
3028 3029
	struct waiting_dir_move *dm = NULL;
	u64 rmdir_ino = 0;
3030 3031
	int ret;

3032
	name = fs_path_alloc();
3033
	from_path = fs_path_alloc();
3034 3035 3036 3037
	if (!name || !from_path) {
		ret = -ENOMEM;
		goto out;
	}
3038

3039 3040 3041 3042
	dm = get_waiting_dir_move(sctx, pm->ino);
	ASSERT(dm);
	rmdir_ino = dm->rmdir_ino;
	free_waiting_dir_move(sctx, dm);
3043 3044 3045

	ret = get_first_ref(sctx->parent_root, pm->ino,
			    &parent_ino, &parent_gen, name);
3046 3047 3048
	if (ret < 0)
		goto out;

3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069
	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;

3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084
	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;

3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113
	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:
3114 3115 3116 3117 3118 3119 3120 3121 3122
	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) {
3123 3124
		if (cur->dir == rmdir_ino)
			continue;
3125 3126 3127 3128 3129 3130
		ret = send_utimes(sctx, cur->dir, cur->dir_gen);
		if (ret < 0)
			goto out;
	}

out:
3131
	fs_path_free(name);
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 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202
	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;
3203
	u64 old_gen;
3204 3205 3206
	struct fs_path *path_before = NULL;
	struct fs_path *path_after = NULL;
	int len1, len2;
3207 3208
	int register_upper_dirs;
	u64 gen;
3209 3210 3211 3212

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

3213 3214 3215
	if (parent_ref->dir <= sctx->cur_ino)
		return 0;

3216 3217 3218 3219 3220 3221 3222
	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;

3223
	if (parent_ref->dir_gen != old_gen)
3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245
		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,
3246
			    &gen, path_after);
3247 3248 3249 3250 3251 3252 3253 3254 3255
	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);
3256 3257
	if (parent_ino_before != parent_ino_after || len1 != len2 ||
	     memcmp(path_before->start, path_after->start, len1)) {
3258 3259 3260 3261 3262
		ret = 1;
		goto out;
	}
	ret = 0;

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 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316
	/*
	 * 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;
	}

3317 3318 3319 3320 3321 3322 3323
out:
	fs_path_free(path_before);
	fs_path_free(path_after);

	return ret;
}

3324 3325 3326
/*
 * This does all the move/link/unlink/rmdir magic.
 */
3327
static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
3328 3329 3330
{
	int ret = 0;
	struct recorded_ref *cur;
3331
	struct recorded_ref *cur2;
3332
	struct list_head check_dirs;
3333
	struct fs_path *valid_path = NULL;
3334
	u64 ow_inode = 0;
3335 3336 3337
	u64 ow_gen;
	int did_overwrite = 0;
	int is_orphan = 0;
3338
	u64 last_dir_ino_rm = 0;
3339 3340 3341

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

3342 3343 3344 3345 3346
	/*
	 * 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);
3347
	INIT_LIST_HEAD(&check_dirs);
3348

3349
	valid_path = fs_path_alloc();
3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387
	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) {
3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427
		/*
		 * 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;
			}
		}

3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439
		/*
		 * 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) {
3440 3441 3442
			ret = is_first_ref(sctx->parent_root,
					   ow_inode, cur->dir, cur->name,
					   cur->name_len);
3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461
			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.
		 */
3462
		if (is_orphan) {
3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476
			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.
				 */
3477 3478 3479 3480
				ret = wait_for_parent_move(sctx, cur);
				if (ret < 0)
					goto out;
				if (ret) {
3481
					ret = add_pending_dir_move(sctx,
3482 3483 3484
							   sctx->cur_ino,
							   sctx->cur_inode_gen,
							   cur->dir);
3485 3486 3487 3488 3489 3490 3491 3492
					*pending_move = 1;
				} else {
					ret = send_rename(sctx, valid_path,
							  cur->full_path);
					if (!ret)
						ret = fs_path_copy(valid_path,
							       cur->full_path);
				}
3493 3494 3495 3496 3497 3498 3499 3500 3501
				if (ret < 0)
					goto out;
			} else {
				ret = send_link(sctx, cur->full_path,
						valid_path);
				if (ret < 0)
					goto out;
			}
		}
3502
		ret = dup_ref(cur, &check_dirs);
3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513
		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.
		 */
3514 3515
		ret = can_rmdir(sctx, sctx->cur_ino, sctx->cur_inode_gen,
				sctx->cur_ino);
3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530
		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) {
3531
			ret = dup_ref(cur, &check_dirs);
3532 3533 3534
			if (ret < 0)
				goto out;
		}
3535 3536 3537 3538 3539 3540 3541
	} 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);
3542
		ret = dup_ref(cur, &check_dirs);
3543 3544
		if (ret < 0)
			goto out;
3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557
	} 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) {
3558 3559 3560
				ret = send_unlink(sctx, cur->full_path);
				if (ret < 0)
					goto out;
3561
			}
3562
			ret = dup_ref(cur, &check_dirs);
3563 3564 3565 3566 3567 3568 3569
			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
3570 3571 3572
		 * inode. Unlinking does not mean that the inode is deleted in
		 * all cases. There may still be links to this inode in other
		 * places.
3573
		 */
3574
		if (is_orphan) {
3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586
			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.
	 */
3587
	list_for_each_entry(cur, &check_dirs, list) {
3588 3589 3590 3591 3592
		/*
		 * 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.
		 */
3593
		if (cur->dir > sctx->cur_ino)
3594 3595
			continue;

3596
		ret = get_cur_inode_state(sctx, cur->dir, cur->dir_gen);
3597 3598 3599 3600 3601 3602
		if (ret < 0)
			goto out;

		if (ret == inode_state_did_create ||
		    ret == inode_state_no_change) {
			/* TODO delayed utimes */
3603
			ret = send_utimes(sctx, cur->dir, cur->dir_gen);
3604 3605
			if (ret < 0)
				goto out;
3606 3607
		} else if (ret == inode_state_did_delete &&
			   cur->dir != last_dir_ino_rm) {
3608 3609
			ret = can_rmdir(sctx, cur->dir, cur->dir_gen,
					sctx->cur_ino);
3610 3611 3612
			if (ret < 0)
				goto out;
			if (ret) {
3613 3614
				ret = get_cur_path(sctx, cur->dir,
						   cur->dir_gen, valid_path);
3615 3616 3617 3618 3619
				if (ret < 0)
					goto out;
				ret = send_rmdir(sctx, valid_path);
				if (ret < 0)
					goto out;
3620
				last_dir_ino_rm = cur->dir;
3621 3622 3623 3624 3625 3626 3627
			}
		}
	}

	ret = 0;

out:
3628
	__free_recorded_refs(&check_dirs);
3629
	free_recorded_refs(sctx);
3630
	fs_path_free(valid_path);
3631 3632 3633
	return ret;
}

3634 3635
static int record_ref(struct btrfs_root *root, int num, u64 dir, int index,
		      struct fs_path *name, void *ctx, struct list_head *refs)
3636 3637 3638 3639 3640 3641
{
	int ret = 0;
	struct send_ctx *sctx = ctx;
	struct fs_path *p;
	u64 gen;

3642
	p = fs_path_alloc();
3643 3644 3645
	if (!p)
		return -ENOMEM;

3646
	ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
3647
			NULL, NULL);
3648 3649 3650 3651 3652 3653 3654 3655 3656 3657
	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;

3658
	ret = __record_ref(refs, dir, gen, p);
3659 3660 3661

out:
	if (ret)
3662
		fs_path_free(p);
3663 3664 3665
	return ret;
}

3666 3667 3668 3669 3670 3671 3672 3673 3674 3675
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);
}


3676 3677 3678 3679 3680
static int __record_deleted_ref(int num, u64 dir, int index,
				struct fs_path *name,
				void *ctx)
{
	struct send_ctx *sctx = ctx;
3681 3682
	return record_ref(sctx->parent_root, num, dir, index, name,
			  ctx, &sctx->deleted_refs);
3683 3684 3685 3686 3687 3688
}

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

3689 3690
	ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
				sctx->cmp_key, 0, __record_new_ref, sctx);
3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702
	if (ret < 0)
		goto out;
	ret = 0;

out:
	return ret;
}

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

3703 3704
	ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
				sctx->cmp_key, 0, __record_deleted_ref, sctx);
3705 3706 3707 3708 3709 3710 3711 3712 3713 3714
	if (ret < 0)
		goto out;
	ret = 0;

out:
	return ret;
}

struct find_ref_ctx {
	u64 dir;
3715 3716
	u64 dir_gen;
	struct btrfs_root *root;
3717 3718 3719 3720 3721 3722 3723 3724 3725
	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_;
3726 3727
	u64 dir_gen;
	int ret;
3728 3729 3730

	if (dir == ctx->dir && fs_path_len(name) == fs_path_len(ctx->name) &&
	    strncmp(name->start, ctx->name->start, fs_path_len(name)) == 0) {
3731 3732 3733 3734 3735 3736 3737 3738 3739 3740
		/*
		 * 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;
3741 3742 3743 3744 3745 3746
		ctx->found_idx = num;
		return 1;
	}
	return 0;
}

3747
static int find_iref(struct btrfs_root *root,
3748 3749
		     struct btrfs_path *path,
		     struct btrfs_key *key,
3750
		     u64 dir, u64 dir_gen, struct fs_path *name)
3751 3752 3753 3754 3755 3756
{
	int ret;
	struct find_ref_ctx ctx;

	ctx.dir = dir;
	ctx.name = name;
3757
	ctx.dir_gen = dir_gen;
3758
	ctx.found_idx = -1;
3759
	ctx.root = root;
3760

3761
	ret = iterate_inode_ref(root, path, key, 0, __find_iref, &ctx);
3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774
	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)
{
3775
	u64 dir_gen;
3776 3777 3778
	int ret;
	struct send_ctx *sctx = ctx;

3779 3780 3781 3782 3783
	ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
			     NULL, NULL, NULL);
	if (ret)
		return ret;

3784
	ret = find_iref(sctx->parent_root, sctx->right_path,
3785
			sctx->cmp_key, dir, dir_gen, name);
3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797
	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)
{
3798
	u64 dir_gen;
3799 3800 3801
	int ret;
	struct send_ctx *sctx = ctx;

3802 3803 3804 3805 3806
	ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
			     NULL, NULL, NULL);
	if (ret)
		return ret;

3807
	ret = find_iref(sctx->send_root, sctx->left_path, sctx->cmp_key,
3808
			dir, dir_gen, name);
3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820
	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;

3821
	ret = iterate_inode_ref(sctx->send_root, sctx->left_path,
3822 3823 3824
			sctx->cmp_key, 0, __record_changed_new_ref, sctx);
	if (ret < 0)
		goto out;
3825
	ret = iterate_inode_ref(sctx->parent_root, sctx->right_path,
3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849
			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;
3850
	int pending_move = 0;
3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862

	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 {
3863 3864 3865 3866
		btrfs_err(sctx->send_root->fs_info,
				"Wrong command %d in process_all_refs", cmd);
		ret = -EINVAL;
		goto out;
3867 3868 3869 3870 3871
	}

	key.objectid = sctx->cmp_key->objectid;
	key.type = BTRFS_INODE_REF_KEY;
	key.offset = 0;
3872 3873 3874
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
3875

3876
	while (1) {
3877 3878
		eb = path->nodes[0];
		slot = path->slots[0];
3879 3880 3881 3882 3883 3884 3885 3886 3887
		if (slot >= btrfs_header_nritems(eb)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				goto out;
			else if (ret > 0)
				break;
			continue;
		}

3888 3889 3890
		btrfs_item_key_to_cpu(eb, &found_key, slot);

		if (found_key.objectid != key.objectid ||
3891 3892
		    (found_key.type != BTRFS_INODE_REF_KEY &&
		     found_key.type != BTRFS_INODE_EXTREF_KEY))
3893 3894
			break;

3895
		ret = iterate_inode_ref(root, path, &found_key, 0, cb, sctx);
3896 3897 3898
		if (ret < 0)
			goto out;

3899
		path->slots[0]++;
3900
	}
3901
	btrfs_release_path(path);
3902

3903 3904 3905
	ret = process_recorded_refs(sctx, &pending_move);
	/* Only applicable to an incremental send. */
	ASSERT(pending_move == 0);
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 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963

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;

3964
	p = fs_path_alloc();
3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990
	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:
3991
	fs_path_free(p);
3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003
	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;

4004
	p = fs_path_alloc();
4005 4006 4007 4008 4009 4010 4011 4012 4013 4014
	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:
4015
	fs_path_free(p);
4016 4017 4018 4019 4020 4021 4022
	return ret;
}

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

4023 4024
	ret = iterate_dir_item(sctx->send_root, sctx->left_path,
			       sctx->cmp_key, __process_new_xattr, sctx);
4025 4026 4027 4028 4029 4030 4031 4032

	return ret;
}

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

4033 4034
	ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
			       sctx->cmp_key, __process_deleted_xattr, sctx);
4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057

	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;
4058
		ctx->found_data = kmemdup(data, data_len, GFP_NOFS);
4059 4060 4061 4062 4063 4064 4065
		if (!ctx->found_data)
			return -ENOMEM;
		return 1;
	}
	return 0;
}

4066
static int find_xattr(struct btrfs_root *root,
4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080
		      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;

4081
	ret = iterate_dir_item(root, path, key, __find_xattr, &ctx);
4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106
	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;

4107 4108 4109
	ret = find_xattr(sctx->parent_root, sctx->right_path,
			 sctx->cmp_key, name, name_len, &found_data,
			 &found_data_len);
4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134
	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;

4135 4136
	ret = find_xattr(sctx->send_root, sctx->left_path, sctx->cmp_key,
			 name, name_len, NULL, NULL);
4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149
	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;

4150
	ret = iterate_dir_item(sctx->send_root, sctx->left_path,
4151 4152 4153
			sctx->cmp_key, __process_changed_new_xattr, sctx);
	if (ret < 0)
		goto out;
4154
	ret = iterate_dir_item(sctx->parent_root, sctx->right_path,
4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179
			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;
4180 4181 4182
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
4183

4184
	while (1) {
4185 4186
		eb = path->nodes[0];
		slot = path->slots[0];
4187 4188 4189 4190 4191 4192 4193 4194 4195 4196
		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;
		}
4197

4198
		btrfs_item_key_to_cpu(eb, &found_key, slot);
4199 4200 4201 4202 4203 4204
		if (found_key.objectid != key.objectid ||
		    found_key.type != key.type) {
			ret = 0;
			goto out;
		}

4205 4206
		ret = iterate_dir_item(root, path, &found_key,
				       __process_new_xattr, sctx);
4207 4208 4209
		if (ret < 0)
			goto out;

4210
		path->slots[0]++;
4211 4212 4213 4214 4215 4216 4217
	}

out:
	btrfs_free_path(path);
	return ret;
}

J
Josef Bacik 已提交
4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248
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
4249 4250 4251 4252 4253 4254 4255

	/* 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
4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290
	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;
}

4291 4292 4293 4294 4295 4296 4297 4298
/*
 * 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
4299
	ssize_t num_read = 0;
4300

4301
	p = fs_path_alloc();
4302 4303 4304 4305 4306
	if (!p)
		return -ENOMEM;

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

J
Josef Bacik 已提交
4307 4308 4309 4310
	num_read = fill_read_buf(sctx, offset, len);
	if (num_read <= 0) {
		if (num_read < 0)
			ret = num_read;
4311
		goto out;
J
Josef Bacik 已提交
4312
	}
4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323

	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);
4324
	TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read);
4325 4326 4327 4328 4329

	ret = send_cmd(sctx);

tlv_put_failure:
out:
4330
	fs_path_free(p);
4331 4332
	if (ret < 0)
		return ret;
4333
	return num_read;
4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349 4350 4351
}

/*
 * 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);

4352
	p = fs_path_alloc();
4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367
	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);

4368
	if (clone_root->root == sctx->send_root) {
4369
		ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
4370
				&gen, NULL, NULL, NULL, NULL);
4371 4372 4373 4374
		if (ret < 0)
			goto out;
		ret = get_cur_path(sctx, clone_root->ino, gen, p);
	} else {
4375
		ret = get_inode_path(clone_root->root, clone_root->ino, p);
4376 4377 4378 4379 4380
	}
	if (ret < 0)
		goto out;

	TLV_PUT_UUID(sctx, BTRFS_SEND_A_CLONE_UUID,
4381
			clone_root->root->root_item.uuid);
4382
	TLV_PUT_U64(sctx, BTRFS_SEND_A_CLONE_CTRANSID,
4383
		    le64_to_cpu(clone_root->root->root_item.ctransid));
4384 4385 4386 4387 4388 4389 4390 4391
	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:
4392
	fs_path_free(p);
4393 4394 4395
	return ret;
}

4396 4397 4398 4399 4400 4401 4402 4403 4404
/*
 * 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;

4405
	p = fs_path_alloc();
4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424
	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:
4425
	fs_path_free(p);
4426 4427 4428
	return ret;
}

4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461
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;
}

4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473
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;
4474
	u64 bs = sctx->send_root->fs_info->sb->s_blocksize;
4475 4476 4477 4478

	ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
			struct btrfs_file_extent_item);
	type = btrfs_file_extent_type(path->nodes[0], ei);
4479
	if (type == BTRFS_FILE_EXTENT_INLINE) {
4480 4481
		len = btrfs_file_extent_inline_len(path->nodes[0],
						   path->slots[0], ei);
4482 4483 4484 4485 4486 4487 4488
		/*
		 * 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 {
4489
		len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
4490
	}
4491 4492 4493 4494 4495 4496 4497 4498

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

4499
	if (clone_root && IS_ALIGNED(offset + len, bs)) {
4500 4501 4502 4503
		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 {
4504 4505 4506 4507 4508 4509 4510 4511 4512 4513 4514 4515 4516 4517 4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538
		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;
4539 4540
	u64 left_gen;
	u64 right_gen;
4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556
	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;
	}
4557 4558 4559 4560
	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);
4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571 4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586 4587 4588 4589 4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601

	/*
	 * 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) {
4602 4603
		/* If we're a hole then just pretend nothing changed */
		ret = (left_disknr) ? 0 : 1;
4604 4605 4606 4607 4608 4609 4610 4611 4612 4613 4614 4615 4616 4617 4618
		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;
		}

4619 4620 4621 4622 4623
		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);

4624 4625 4626 4627
		/*
		 * Are we at extent 8? If yes, we know the extent is changed.
		 * This may only happen on the first iteration.
		 */
4628
		if (found_key.offset + right_len <= ekey->offset) {
4629 4630
			/* If we're a hole just pretend nothing changed */
			ret = (left_disknr) ? 0 : 1;
4631 4632 4633 4634 4635 4636 4637 4638 4639 4640 4641 4642 4643 4644 4645
			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.
		 */
4646
		if (left_disknr != right_disknr ||
4647 4648
		    left_offset_fixed != right_offset ||
		    left_gen != right_gen) {
4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660 4661 4662 4663 4664 4665 4666 4667
			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;
4668 4669 4670 4671
		}
		if (found_key.offset != key.offset + right_len) {
			ret = 0;
			goto out;
4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690
		}
		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;
}

4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721
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) {
4722 4723
		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
							path->slots[0], fi);
4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744 4745 4746 4747 4748 4749 4750 4751 4752 4753 4754 4755 4756
		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) {
4757 4758
		u64 size = btrfs_file_extent_inline_len(path->nodes[0],
							path->slots[0], fi);
4759 4760 4761 4762 4763 4764
		extent_end = ALIGN(key->offset + size,
				   sctx->send_root->sectorsize);
	} else {
		extent_end = key->offset +
			btrfs_file_extent_num_bytes(path->nodes[0], fi);
	}
4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 4776 4777 4778 4779

	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;
	}

4780 4781 4782 4783 4784 4785
	if (sctx->cur_inode_last_extent < key->offset)
		ret = send_hole(sctx, key->offset);
	sctx->cur_inode_last_extent = extent_end;
	return ret;
}

4786 4787 4788 4789 4790
static int process_extent(struct send_ctx *sctx,
			  struct btrfs_path *path,
			  struct btrfs_key *key)
{
	struct clone_root *found_clone = NULL;
4791
	int ret = 0;
4792 4793 4794 4795 4796 4797 4798 4799 4800 4801

	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;
4802
			goto out_hole;
4803
		}
4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829
	} 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;
			}
		}
4830 4831 4832 4833 4834 4835 4836 4837
	}

	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);
4838 4839 4840 4841
	if (ret)
		goto out;
out_hole:
	ret = maybe_send_hole(sctx, path, key);
4842 4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863
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;
4864 4865 4866
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
4867

4868
	while (1) {
4869 4870
		eb = path->nodes[0];
		slot = path->slots[0];
4871 4872 4873 4874 4875 4876 4877 4878 4879 4880 4881 4882

		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;
		}

4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894
		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;

4895
		path->slots[0]++;
4896 4897 4898 4899 4900 4901 4902
	}

out:
	btrfs_free_path(path);
	return ret;
}

4903 4904 4905
static int process_recorded_refs_if_needed(struct send_ctx *sctx, int at_end,
					   int *pending_move,
					   int *refs_processed)
4906 4907 4908 4909 4910 4911
{
	int ret = 0;

	if (sctx->cur_ino == 0)
		goto out;
	if (!at_end && sctx->cur_ino == sctx->cmp_key->objectid &&
4912
	    sctx->cmp_key->type <= BTRFS_INODE_EXTREF_KEY)
4913 4914 4915 4916
		goto out;
	if (list_empty(&sctx->new_refs) && list_empty(&sctx->deleted_refs))
		goto out;

4917
	ret = process_recorded_refs(sctx, pending_move);
4918 4919 4920
	if (ret < 0)
		goto out;

4921
	*refs_processed = 1;
4922 4923 4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936
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;
4937 4938
	int pending_move = 0;
	int refs_processed = 0;
4939

4940 4941
	ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move,
					      &refs_processed);
4942 4943 4944
	if (ret < 0)
		goto out;

4945 4946 4947 4948 4949 4950 4951 4952 4953 4954 4955 4956 4957 4958 4959
	/*
	 * 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;

4960 4961 4962 4963 4964 4965
	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,
4966
			&left_mode, &left_uid, &left_gid, NULL);
4967 4968 4969
	if (ret < 0)
		goto out;

4970 4971 4972
	if (!sctx->parent_root || sctx->cur_inode_new) {
		need_chown = 1;
		if (!S_ISLNK(sctx->cur_inode_mode))
4973
			need_chmod = 1;
4974 4975 4976 4977 4978 4979
	} 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;
4980

4981 4982 4983 4984
		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;
4985 4986 4987
	}

	if (S_ISREG(sctx->cur_inode_mode)) {
4988
		if (need_send_hole(sctx)) {
4989 4990 4991
			if (sctx->cur_inode_last_extent == (u64)-1 ||
			    sctx->cur_inode_last_extent <
			    sctx->cur_inode_size) {
4992 4993 4994 4995 4996 4997 4998 4999 5000 5001 5002
				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;
			}
		}
5003 5004 5005 5006 5007 5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022
		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;
	}

	/*
5023 5024
	 * If other directory inodes depended on our current directory
	 * inode's move/rename, now do their move/rename operations.
5025
	 */
5026 5027 5028 5029
	if (!is_waiting_for_move(sctx, sctx->cur_ino)) {
		ret = apply_children_dir_moves(sctx);
		if (ret)
			goto out;
5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040
		/*
		 * 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;
5041 5042
	}

5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058
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;
5059
	sctx->cur_inode_last_extent = (u64)-1;
5060 5061 5062 5063 5064 5065

	/*
	 * 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.
	 */
5066 5067 5068 5069 5070 5071 5072 5073 5074 5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088
	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);
5089 5090 5091 5092 5093 5094 5095 5096

		/*
		 * 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)
5097 5098 5099 5100 5101 5102 5103 5104 5105 5106 5107
			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
5108 5109
		sctx->cur_inode_rdev = btrfs_inode_rdev(
				sctx->left_path->nodes[0], left_ii);
5110
		if (sctx->cur_ino != BTRFS_FIRST_FREE_OBJECTID)
5111
			ret = send_create_inode_if_needed(sctx);
5112 5113 5114 5115 5116 5117 5118 5119 5120
	} 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) {
5121 5122 5123 5124 5125 5126 5127
		/*
		 * 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.
		 */
5128
		if (sctx->cur_inode_new_gen) {
5129 5130 5131
			/*
			 * First, process the inode as if it was deleted.
			 */
5132 5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143
			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;

5144 5145 5146
			/*
			 * Now process the inode as if it was new.
			 */
5147 5148 5149 5150 5151 5152 5153
			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
5154 5155
			sctx->cur_inode_rdev = btrfs_inode_rdev(
					sctx->left_path->nodes[0], left_ii);
5156
			ret = send_create_inode_if_needed(sctx);
5157 5158 5159 5160 5161 5162
			if (ret < 0)
				goto out;

			ret = process_all_refs(sctx, BTRFS_COMPARE_TREE_NEW);
			if (ret < 0)
				goto out;
5163 5164 5165 5166 5167
			/*
			 * 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;
5168 5169 5170 5171 5172

			/*
			 * Now process all extents and xattrs of the inode as if
			 * they were all new.
			 */
5173 5174 5175 5176 5177 5178 5179 5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194
			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;
}

5195 5196 5197 5198 5199 5200 5201 5202 5203 5204
/*
 * 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.
 */
5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224
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;
}

5225 5226 5227 5228 5229
/*
 * 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
 */
5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248
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;
}

5249 5250 5251 5252 5253
/*
 * 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
 */
5254 5255 5256 5257 5258 5259 5260 5261 5262 5263 5264 5265 5266 5267 5268 5269
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;
}

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 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317 5318 5319 5320 5321 5322 5323 5324 5325 5326 5327
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;
}

5328 5329 5330 5331
/*
 * Updates compare related fields in sctx and simply forwards to the actual
 * changed_xxx functions.
 */
5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342
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;

5343
	if (result == BTRFS_COMPARE_TREE_SAME) {
5344 5345 5346 5347 5348 5349 5350 5351 5352 5353
		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 {
5354
			return 0;
5355
		}
5356 5357 5358 5359
		result = BTRFS_COMPARE_TREE_CHANGED;
		ret = 0;
	}

5360 5361 5362 5363 5364 5365 5366 5367
	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;

5368 5369 5370 5371 5372
	/* Ignore non-FS objects */
	if (key->objectid == BTRFS_FREE_INO_OBJECTID ||
	    key->objectid == BTRFS_FREE_SPACE_OBJECTID)
		goto out;

5373 5374
	if (key->type == BTRFS_INODE_ITEM_KEY)
		ret = changed_inode(sctx, result);
5375 5376
	else if (key->type == BTRFS_INODE_REF_KEY ||
		 key->type == BTRFS_INODE_EXTREF_KEY)
5377 5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426 5427 5428 5429 5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445
		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;
	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;

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

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

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

	while (1) {
		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);
	return ret;
}

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

5446 5447 5448 5449 5450
	if (!(sctx->flags & BTRFS_SEND_FLAG_OMIT_STREAM_HEADER)) {
		ret = send_header(sctx);
		if (ret < 0)
			goto out;
	}
5451 5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474

	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;
}

5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489
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);
}

5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500
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;
5501
	int clone_sources_to_rollback = 0;
5502
	int sort_clone_roots = 0;
5503
	int index;
5504 5505 5506 5507

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

A
Al Viro 已提交
5508
	send_root = BTRFS_I(file_inode(mnt_file))->root;
5509 5510
	fs_info = send_root->fs_info;

5511 5512 5513 5514 5515 5516 5517 5518
	/*
	 * 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
5519 5520 5521 5522 5523 5524
	/*
	 * 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);

5525 5526 5527 5528 5529 5530 5531 5532 5533
	/*
	 * Userspace tools do the checks and warn the user if it's
	 * not RO.
	 */
	if (!btrfs_root_readonly(send_root)) {
		ret = -EPERM;
		goto out;
	}

5534 5535 5536 5537 5538 5539 5540 5541
	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,
5542 5543
			sizeof(*arg->clone_sources) *
			arg->clone_sources_count)) {
5544 5545 5546 5547
		ret = -EFAULT;
		goto out;
	}

5548
	if (arg->flags & ~BTRFS_SEND_FLAG_MASK) {
5549 5550 5551 5552
		ret = -EINVAL;
		goto out;
	}

5553 5554 5555 5556 5557 5558 5559 5560 5561 5562 5563
	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);

5564 5565
	sctx->flags = arg->flags;

5566
	sctx->send_filp = fget(arg->send_fd);
5567 5568
	if (!sctx->send_filp) {
		ret = -EBADF;
5569 5570 5571 5572 5573 5574 5575 5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587
		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;
	}

5588 5589
	sctx->pending_dir_moves = RB_ROOT;
	sctx->waiting_dir_moves = RB_ROOT;
5590
	sctx->orphan_dirs = RB_ROOT;
5591

5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618
	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;
5619 5620 5621

			index = srcu_read_lock(&fs_info->subvol_srcu);

5622 5623
			clone_root = btrfs_read_fs_root_no_name(fs_info, &key);
			if (IS_ERR(clone_root)) {
5624
				srcu_read_unlock(&fs_info->subvol_srcu, index);
5625 5626 5627
				ret = PTR_ERR(clone_root);
				goto out;
			}
5628 5629 5630 5631 5632
			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);
5633
				srcu_read_unlock(&fs_info->subvol_srcu, index);
5634 5635 5636 5637
				ret = -EPERM;
				goto out;
			}
			spin_unlock(&clone_root->root_item_lock);
5638 5639
			srcu_read_unlock(&fs_info->subvol_srcu, index);

5640 5641 5642 5643 5644 5645 5646 5647 5648 5649
			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;
5650 5651 5652

		index = srcu_read_lock(&fs_info->subvol_srcu);

5653
		sctx->parent_root = btrfs_read_fs_root_no_name(fs_info, &key);
5654
		if (IS_ERR(sctx->parent_root)) {
5655
			srcu_read_unlock(&fs_info->subvol_srcu, index);
5656
			ret = PTR_ERR(sctx->parent_root);
5657 5658
			goto out;
		}
5659

5660 5661 5662 5663
		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);
5664
			srcu_read_unlock(&fs_info->subvol_srcu, index);
5665 5666 5667 5668
			ret = -EPERM;
			goto out;
		}
		spin_unlock(&sctx->parent_root->root_item_lock);
5669 5670

		srcu_read_unlock(&fs_info->subvol_srcu, index);
5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683
	}

	/*
	 * 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);
5684
	sort_clone_roots = 1;
5685

5686
	current->journal_info = (void *)BTRFS_SEND_TRANS_STUB;
5687
	ret = send_subvol(sctx);
5688
	current->journal_info = NULL;
5689 5690 5691
	if (ret < 0)
		goto out;

5692 5693 5694 5695 5696 5697 5698 5699
	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;
	}
5700 5701

out:
5702 5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724 5725 5726 5727 5728 5729
	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);
	}

5730 5731 5732 5733 5734 5735 5736 5737 5738 5739
	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);
	}

5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750
	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);
	}
5751 5752
	if (sctx && !IS_ERR_OR_NULL(sctx->parent_root))
		btrfs_root_dec_send_in_progress(sctx->parent_root);
5753

5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771
	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;
}