On Tue, Sep 11, 2018 at 03:28:06PM +1000, Ronnie Sahlberg wrote: > Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx> > --- > src/cloner.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/src/cloner.c b/src/cloner.c > index ffad82f0..9f9156e5 100644 > --- a/src/cloner.c > +++ b/src/cloner.c > @@ -120,6 +120,18 @@ clone_file_range_btrfs(int src_fd, int dst_fd, uint64_t src_off, > } > > static int > +clone_file_range_cifs(int fd_in, int fd_out, loff_t off_in, > + loff_t off_out, size_t len) > +{ > + int ret; > + > + ret = copy_file_range(fd_in, &off_in, fd_out, &off_out, len, 0); > + if (ret < 0) > + ret = errno; > + return 0; > +} This is weird. cloner seems to test clone, in which case it should test FICLONE (BTRFS_IOC_CLONE) / FICLONERANGE(BTRFS_IOC_CLONE_RANGE). But it seems to check file system magic numbers which is rather bogus to start with. I think the right fix here is to remove all the magic number checks, always try FICLONE, and also remove support for the odd legacy cifs ioctl. > { > @@ -128,7 +140,9 @@ clone_file_range(unsigned int fs_type, int src_fd, int dst_fd, uint64_t src_off, > return clone_file_range_btrfs(src_fd, dst_fd, src_off, dst_off, > len); > break; > - case CIFS_MAGIC_NUMBER: /* only supports full file server-side copies */ > + case CIFS_MAGIC_NUMBER: > + return clone_file_range_cifs(src_fd, dst_fd, src_off, dst_off, > + len); > default: > return ENOTSUP; > break; And independent break after a return is just insane. Someone needs to fix this program to stop the eye bleeding..