linux/fs/btrfs/send.h
Omar Sandoval 8c7d9fe06f btrfs: send: avoid copying file data
send_write() currently copies from the page cache to sctx->read_buf, and
then from sctx->read_buf to sctx->send_buf. Similarly, send_hole()
zeroes sctx->read_buf and then copies from sctx->read_buf to
sctx->send_buf. However, if we write the TLV header manually, we can
copy to sctx->send_buf directly and get rid of sctx->read_buf.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-10-07 12:13:17 +02:00

125 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2012 Alexander Block. All rights reserved.
* Copyright (C) 2012 STRATO. All rights reserved.
*/
#ifndef BTRFS_SEND_H
#define BTRFS_SEND_H
#include "ctree.h"
#define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
#define BTRFS_SEND_STREAM_VERSION 1
#define BTRFS_SEND_BUF_SIZE SZ_64K
enum btrfs_tlv_type {
BTRFS_TLV_U8,
BTRFS_TLV_U16,
BTRFS_TLV_U32,
BTRFS_TLV_U64,
BTRFS_TLV_BINARY,
BTRFS_TLV_STRING,
BTRFS_TLV_UUID,
BTRFS_TLV_TIMESPEC,
};
struct btrfs_stream_header {
char magic[sizeof(BTRFS_SEND_STREAM_MAGIC)];
__le32 version;
} __attribute__ ((__packed__));
struct btrfs_cmd_header {
/* len excluding the header */
__le32 len;
__le16 cmd;
/* crc including the header with zero crc field */
__le32 crc;
} __attribute__ ((__packed__));
struct btrfs_tlv_header {
__le16 tlv_type;
/* len excluding the header */
__le16 tlv_len;
} __attribute__ ((__packed__));
/* commands */
enum btrfs_send_cmd {
BTRFS_SEND_C_UNSPEC,
BTRFS_SEND_C_SUBVOL,
BTRFS_SEND_C_SNAPSHOT,
BTRFS_SEND_C_MKFILE,
BTRFS_SEND_C_MKDIR,
BTRFS_SEND_C_MKNOD,
BTRFS_SEND_C_MKFIFO,
BTRFS_SEND_C_MKSOCK,
BTRFS_SEND_C_SYMLINK,
BTRFS_SEND_C_RENAME,
BTRFS_SEND_C_LINK,
BTRFS_SEND_C_UNLINK,
BTRFS_SEND_C_RMDIR,
BTRFS_SEND_C_SET_XATTR,
BTRFS_SEND_C_REMOVE_XATTR,
BTRFS_SEND_C_WRITE,
BTRFS_SEND_C_CLONE,
BTRFS_SEND_C_TRUNCATE,
BTRFS_SEND_C_CHMOD,
BTRFS_SEND_C_CHOWN,
BTRFS_SEND_C_UTIMES,
BTRFS_SEND_C_END,
BTRFS_SEND_C_UPDATE_EXTENT,
__BTRFS_SEND_C_MAX,
};
#define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1)
/* attributes in send stream */
enum {
BTRFS_SEND_A_UNSPEC,
BTRFS_SEND_A_UUID,
BTRFS_SEND_A_CTRANSID,
BTRFS_SEND_A_INO,
BTRFS_SEND_A_SIZE,
BTRFS_SEND_A_MODE,
BTRFS_SEND_A_UID,
BTRFS_SEND_A_GID,
BTRFS_SEND_A_RDEV,
BTRFS_SEND_A_CTIME,
BTRFS_SEND_A_MTIME,
BTRFS_SEND_A_ATIME,
BTRFS_SEND_A_OTIME,
BTRFS_SEND_A_XATTR_NAME,
BTRFS_SEND_A_XATTR_DATA,
BTRFS_SEND_A_PATH,
BTRFS_SEND_A_PATH_TO,
BTRFS_SEND_A_PATH_LINK,
BTRFS_SEND_A_FILE_OFFSET,
BTRFS_SEND_A_DATA,
BTRFS_SEND_A_CLONE_UUID,
BTRFS_SEND_A_CLONE_CTRANSID,
BTRFS_SEND_A_CLONE_PATH,
BTRFS_SEND_A_CLONE_OFFSET,
BTRFS_SEND_A_CLONE_LEN,
__BTRFS_SEND_A_MAX,
};
#define BTRFS_SEND_A_MAX (__BTRFS_SEND_A_MAX - 1)
#ifdef __KERNEL__
long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg);
#endif
#endif