btrfs: fix btrfs_snapshot()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/storage/btrfs.c b/src/lxc/storage/btrfs.c
index c351bee67e056b00e727d53c1c25e8cf4646dd5d..d2727b6dce999da9fc442111ae88a9fdf74d6acc 100644 (file)
--- a/src/lxc/storage/btrfs.c
+++ b/src/lxc/storage/btrfs.c
@@ -310,49 +310,52 @@ out:
 
 int btrfs_snapshot(const char *orig, const char *new)
 {
-       int fd, fddst, ret;
        size_t retlen;
        struct btrfs_ioctl_vol_args_v2 args;
        char *newdir, *newname;
        char *newfull = NULL;
+       int saved_errno = -1;
+       int fd = -1, fddst = -1, ret = -1;
 
        newfull = strdup(new);
-       if (!newfull) {
-               ERROR("Error: out of memory");
+       if (!newfull)
                goto out;
-       }
-       // make sure the directory doesn't already exist
-       if (rmdir(newfull) < 0 && errno != ENOENT) {
-               SYSERROR("Error removing empty new rootfs");
+
+       ret = rmdir(newfull);
+       if (ret < 0 && errno != ENOENT)
                goto out;
-       }
+
        newname = basename(newfull);
-       newdir = dirname(newfull);
        fd = open(orig, O_RDONLY);
-       if (fd < 0) {
-               SYSERROR("Error opening original rootfs %s", orig);
+       if (fd < 0)
                goto out;
-       }
+
+       newdir = dirname(newfull);
        fddst = open(newdir, O_RDONLY);
-       if (fddst < 0) {
-               SYSERROR("Error opening new container dir %s", newdir);
+       if (fddst < 0)
                goto out;
-       }
 
        memset(&args, 0, sizeof(args));
+       args.fd = fd;
        retlen = strlcpy(args.name, newname, BTRFS_SUBVOL_NAME_MAX);
        if (retlen >= BTRFS_SUBVOL_NAME_MAX)
                goto out;
 
        ret = ioctl(fddst, BTRFS_IOC_SNAP_CREATE_V2, &args);
-       INFO("btrfs: snapshot create ioctl returned %d", ret);
+       saved_errno = errno;
 
 out:
        if (fddst != -1)
                close(fddst);
+
        if (fd != -1)
                close(fd);
+
        free(newfull);
+
+       if (saved_errno >= 0)
+               errno = saved_errno;
+
        return ret;
 }