After this patch, I'd like to only re-introduce the original lxc-clone
bash script's command line options in the new c program, then push to
staging.
Subject: [PATCH 2/3] on copy-clone of btrfs, create a subvolume
so that it can be snapshotted.
Signed-off-by: Serge Hallyn <serge.hal...@ubuntu.com>
---
src/lxc/bdev.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 58 insertions(+), 10 deletions(-)
diff --git a/src/lxc/bdev.c b/src/lxc/bdev.c
index 25d2650..68e8d3d 100644
--- a/src/lxc/bdev.c
+++ b/src/lxc/bdev.c
@@ -681,14 +681,23 @@ int btrfs_umount(struct bdev *bdev)
return umount(bdev->dest);
}
+#define BTRFS_SUBVOL_NAME_MAX 4039
+#define BTRFS_PATH_NAME_MAX 4087
+
+struct btrfs_ioctl_vol_args {
+ signed long long fd;
+ char name[BTRFS_PATH_NAME_MAX + 1];
+};
+
#define BTRFS_IOCTL_MAGIC 0x94
#define BTRFS_IOC_SUBVOL_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 24, \
struct btrfs_ioctl_vol_args_v2)
#define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
struct btrfs_ioctl_vol_args_v2)
+#define BTRFS_IOC_SUBVOL_CREATE _IOW(BTRFS_IOCTL_MAGIC, 14, \
+ struct btrfs_ioctl_vol_args)
#define BTRFS_QGROUP_INHERIT_SET_LIMITS (1ULL << 0)
-#define BTRFS_SUBVOL_NAME_MAX 4039
struct btrfs_ioctl_vol_args_v2 {
signed long long fd;
@@ -705,6 +714,42 @@ struct btrfs_ioctl_vol_args_v2 {
char name[BTRFS_SUBVOL_NAME_MAX + 1];
};
+static int btrfs_subvolume_create(const char *path)
+{
+ int ret, fd = -1;
+ struct btrfs_ioctl_vol_args args;
+ char *p, *newfull = strdup(path);
+
+ if (!newfull) {
+ ERROR("Error: out of memory");
+ return -1;
+ }
+
+ p = rindex(newfull, '/');
+ if (!p) {
+ free(newfull);
+ ERROR("bad path: %s", path);
+ return -1;
+ }
+ *p = '\0';
+
+ if ((fd = open(newfull, O_RDONLY)) < 0) {
+ ERROR("Error opening %s", newfull);
+ free(newfull);
+ return -1;
+ }
+
+ memset(&args, 0, sizeof(args));
+ strncpy(args.name, p+1, BTRFS_SUBVOL_NAME_MAX);
+ args.name[BTRFS_SUBVOL_NAME_MAX-1] = 0;
+ ret = ioctl(fd, BTRFS_IOC_SUBVOL_CREATE, &args);
+ INFO("btrfs: snapshot create ioctl returned %d", ret);
+
+ free(newfull);
+ close(fd);
+ return ret;
+}
+
static int btrfs_snapshot(const char *orig, const char *new)
{
int fd = -1, fddst = -1, ret = -1;
@@ -755,24 +800,27 @@ static int btrfs_clonepaths(struct bdev *orig, struct
bdev *new, const char *old
const char *cname, const char *oldpath, const char *lxcpath,
int snap,
unsigned long newsize)
{
- if (!snap)
- return dir_clonepaths(orig, new, oldname, cname, oldpath,
lxcpath,
- snap, newsize);
-
- if (!orig->src || !orig->dest)
+ if (!orig->dest || !orig->src)
return -1;
- new->dest = dir_new_path(orig->dest, oldname, cname, oldpath, lxcpath);
- if (!new->dest)
+ if ((new->dest = dir_new_path(orig->dest, oldname, cname, oldpath,
lxcpath)) == NULL)
return -1;
if ((new->src = strdup(new->dest)) == NULL)
return -1;
- if (btrfs_snapshot(orig->dest, new->dest) < 0)
+ if (orig->data && (new->data = strdup(orig->data)) == NULL)
return -1;
- return 0;
+ if (snap)
+ return btrfs_snapshot(orig->dest, new->dest);
+
+ if (rmdir(new->dest) < 0 && errno != -ENOENT) {
+ SYSERROR("removing %s\n", new->dest);
+ return -1;
+ }
+
+ return btrfs_subvolume_create(new->dest);
}
struct bdev_ops btrfs_ops = {
--
1.8.1.2
------------------------------------------------------------------------------
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