From 1c7dd82563ff2e71a067aea20d2acb2d0553644b Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Sat, 17 Jan 2015 18:11:45 +0100
Subject: qcow2: when dissecting qcow2, use btrfs clone ioctls for reflinking
 blocks to target

---
 src/shared/btrfs-util.c | 20 ++++++++++++++++++++
 src/shared/btrfs-util.h |  1 +
 2 files changed, 21 insertions(+)

(limited to 'src/shared')

diff --git a/src/shared/btrfs-util.c b/src/shared/btrfs-util.c
index bd100eef0b..254483c31a 100644
--- a/src/shared/btrfs-util.c
+++ b/src/shared/btrfs-util.c
@@ -275,6 +275,26 @@ int btrfs_reflink(int infd, int outfd) {
         return 0;
 }
 
+int btrfs_clone_range(int infd, uint64_t in_offset, int outfd, uint64_t out_offset, uint64_t sz) {
+        struct btrfs_ioctl_clone_range_args args = {
+                .src_fd = infd,
+                .src_offset = in_offset,
+                .src_length = sz,
+                .dest_offset = out_offset,
+        };
+        int r;
+
+        assert(infd >= 0);
+        assert(outfd >= 0);
+        assert(sz > 0);
+
+        r = ioctl(outfd, BTRFS_IOC_CLONE_RANGE, &args);
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
 int btrfs_get_block_device(const char *path, dev_t *dev) {
         struct btrfs_ioctl_fs_info_args fsi = {};
         _cleanup_close_ int fd = -1;
diff --git a/src/shared/btrfs-util.h b/src/shared/btrfs-util.h
index 1bff9171d7..28946c60c9 100644
--- a/src/shared/btrfs-util.h
+++ b/src/shared/btrfs-util.h
@@ -55,6 +55,7 @@ int btrfs_subvol_get_info_fd(int fd, BtrfsSubvolInfo *info);
 int btrfs_subvol_get_quota_fd(int fd, BtrfsQuotaInfo *quota);
 
 int btrfs_reflink(int infd, int outfd);
+int btrfs_clone_range(int infd, uint64_t in_offset, int ofd, uint64_t out_offset, uint64_t sz);
 
 int btrfs_get_block_device(const char *path, dev_t *dev);
 
-- 
cgit v1.2.3-54-g00ecf