From: Chen Yang <chenyang.fnst@xxxxxxxxxxxxxx>
Date: Fri, 18 Jan 2013 14:54:31 +0800
Subject: [PATCH] Btrfs-progs/receive: sparse and pre-allocated file support
for btrfs-send mechanism
When sending a file with sparse or pre-allocated part,
these parts will be sent as ZERO streams, and it's unnecessary.
To improve this, we add a punch command on the sending side, so the
receiving side changed with it. The main change is adding the punch
processing to receive command.
Signed-off-by: Cheng Yang <chenyang.fnst@xxxxxxxxxxxxxx>
---
cmds-receive.c | 27 +++++++++++++++++++++++++++
send-stream.c | 6 ++++++
send-stream.h | 1 +
send.h | 3 ++-
4 files changed, 36 insertions(+), 1 deletions(-)
diff --git a/cmds-receive.c b/cmds-receive.c
index a8be6fa..74cbfc4 100644
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -37,6 +37,7 @@
#include <sys/types.h>
#include <sys/xattr.h>
#include <uuid/uuid.h>
+#include <linux/falloc.h>
#include "ctree.h"
#include "ioctl.h"
@@ -508,6 +509,31 @@ out:
return ret;
}
+static int process_punch(const char *path, u64 offset, u64 len, void *user)
+{
+ int ret = 0;
+ struct btrfs_receive *r = user;
+ char *full_path = path_cat(r->full_subvol_path, path);
+
+ ret = open_inode_for_write(r, full_path);
+ if (ret < 0)
+ goto out;
+
+ ret = fallocate(r->write_fd,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ offset, len);
+ if (ret < 0) {
+ ret = -errno;
+ fprintf(stderr, "ERROR: punch %s failed. %s\n",
+ path, strerror(-ret));
+ goto out;
+ }
+
+out:
+ free(full_path);
+ return ret;
+}
+
static int process_write(const char *path, const void *data, u64 offset,
u64 len, void *user)
{
@@ -777,6 +803,7 @@ struct btrfs_send_ops send_ops = {
.link = process_link,
.unlink = process_unlink,
.rmdir = process_rmdir,
+ .punch = process_punch,
.write = process_write,
.clone = process_clone,
.set_xattr = process_set_xattr,
diff --git a/send-stream.c b/send-stream.c
index 55fa728..9f3ede7 100644
--- a/send-stream.c
+++ b/send-stream.c
@@ -362,6 +362,12 @@ static int read_and_process_cmd(struct btrfs_send_stream *s)
TLV_GET_STRING(s, BTRFS_SEND_A_PATH, &path);
ret = s->ops->rmdir(path, s->user);
break;
+ case BTRFS_SEND_C_PUNCH:
+ TLV_GET_STRING(s, BTRFS_SEND_A_PATH, &path);
+ TLV_GET_U64(s, BTRFS_SEND_A_FILE_OFFSET, &offset);
+ TLV_GET_U64(s, BTRFS_SEND_A_SIZE, &len);
+ ret = s->ops->punch(path, offset, len, s->user);
+ break;
case BTRFS_SEND_C_WRITE:
TLV_GET_STRING(s, BTRFS_SEND_A_PATH, &path);
TLV_GET_U64(s, BTRFS_SEND_A_FILE_OFFSET, &offset);
diff --git a/send-stream.h b/send-stream.h
index b69b7f1..f83f2ac 100644
--- a/send-stream.h
+++ b/send-stream.h
@@ -34,6 +34,7 @@ struct btrfs_send_ops {
int (*link)(const char *path, const char *lnk, void *user);
int (*unlink)(const char *path, void *user);
int (*rmdir)(const char *path, void *user);
+ int (*punch)(const char *path, u64 offset, u64 len, void *user);
int (*write)(const char *path, const void *data, u64 offset, u64 len,
void *user);
int (*clone)(const char *path, u64 offset, u64 len,
diff --git a/send.h b/send.h
index 9934e94..10a88d2 100644
--- a/send.h
+++ b/send.h
@@ -20,7 +20,7 @@
#include "ctree.h"
#define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
-#define BTRFS_SEND_STREAM_VERSION 1
+#define BTRFS_SEND_STREAM_VERSION 2
#define BTRFS_SEND_BUF_SIZE (1024 * 64)
#define BTRFS_SEND_READ_SIZE (1024 * 48)
@@ -80,6 +80,7 @@ enum btrfs_send_cmd {
BTRFS_SEND_C_WRITE,
BTRFS_SEND_C_CLONE,
+ BTRFS_SEND_C_PUNCH,
BTRFS_SEND_C_TRUNCATE,
BTRFS_SEND_C_CHMOD,
BTRFS_SEND_C_CHOWN,
--
1.7.7.6
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
