From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mo4-p00-ob.smtp.rzone.de ([81.169.146.216]:45708 "EHLO mo4-p00-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932116AbbD0H2T (ORCPT ); Mon, 27 Apr 2015 03:28:19 -0400 Message-ID: <553DE512.7080606@giantdisaster.de> Date: Mon, 27 Apr 2015 09:28:18 +0200 From: Stefan Behrens MIME-Version: 1.0 To: =?UTF-8?B?TGF1cmkgVsO1c2FuZGk=?= , linux-btrfs@vger.kernel.org Subject: Re: [PATCH] btrfs-progs: receive explicit parent support References: <1430043165-20641-1-git-send-email-lauri.vosandi@gmail.com> In-Reply-To: <1430043165-20641-1-git-send-email-lauri.vosandi@gmail.com> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Sun, 26 Apr 2015 12:12:45 +0200, Lauri Võsandi wrote: > This patch adds command-line flag -p to btrfs receive > which makes it possible to disable automatic parent > search for incremental snapshots and use explicitly > specified path instead. > > Signed-off-by: Lauri Võsandi > --- > cmds-receive.c | 34 ++++++++++++++++++++++++++-------- > 1 file changed, 26 insertions(+), 8 deletions(-) > > diff --git a/cmds-receive.c b/cmds-receive.c > index b7cf3f9..391d281 100644 > --- a/cmds-receive.c > +++ b/cmds-receive.c > @@ -61,6 +61,7 @@ struct btrfs_receive > char *root_path; > char *dest_dir_path; /* relative to root_path */ > char *full_subvol_path; > + char *explicit_parent_path; > int dest_dir_chroot; > > struct subvol_info *cur_subvol; > @@ -220,20 +221,32 @@ static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid, > fprintf(stderr, "receiving snapshot %s uuid=%s, " > "ctransid=%llu ", path, uuid_str, > r->cur_subvol->stransid); > - uuid_unparse(parent_uuid, uuid_str); > - fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n", > - uuid_str, parent_ctransid); > } > > memset(&args_v2, 0, sizeof(args_v2)); > strncpy_null(args_v2.name, path); > > - parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid, > - parent_ctransid, NULL, subvol_search_by_received_uuid); > - if (!parent_subvol) { > + if (r->explicit_parent_path) { > + if (g_verbose) { > + fprintf(stderr, "using explicit parent %s\n", > + r->explicit_parent_path); > + } > + parent_subvol = subvol_uuid_search(&r->sus, 0, NULL, > + 0, r->explicit_parent_path, subvol_search_by_path); This won't work if you receive more than one snapshot, each one derived from the previous one ("btrfs send -e snap1 snap2 snap3 snap4"). You would always use the first one as the parent, not the predecessor. That's implemented differently for the -p option in git://git.kernel.org/pub/scm/linux/kernel/git/arne/far-progs.git > + } else { > + if (g_verbose) { > + uuid_unparse(parent_uuid, uuid_str); > + fprintf(stderr, "parent_uuid=%s, parent_ctransid=%llu\n", > + uuid_str, parent_ctransid); > + } > parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid, > - parent_ctransid, NULL, subvol_search_by_uuid); > + parent_ctransid, NULL, subvol_search_by_received_uuid); > + if (!parent_subvol) { > + parent_subvol = subvol_uuid_search(&r->sus, 0, parent_uuid, > + parent_ctransid, NULL, subvol_search_by_uuid); > + } This used to be a search for the received_uuid only. Why is this code changed like this in the branch that is executed when -p is not specified, in a patch that has the goal to add -p with new functionality if -p is specified? > } > + > if (!parent_subvol) { > ret = -ENOENT; > fprintf(stderr, "ERROR: could not find parent subvolume\n"); > @@ -962,11 +975,14 @@ int cmd_receive(int argc, char **argv) > { NULL, 0, NULL, 0 } > }; > > - c = getopt_long(argc, argv, "Cevf:", long_opts, NULL); > + c = getopt_long(argc, argv, "Cevf:p:", long_opts, NULL); > if (c < 0) > break; > > switch (c) { > + case 'p': > + r.explicit_parent_path = optarg; > + break; > case 'v': > g_verbose++; > break; > @@ -1028,6 +1044,8 @@ const char * const cmd_receive_usage[] = { > " in the data stream. Without this option,", > " the receiver terminates only if an error", > " is recognized or on EOF.", > + "-p Disables the automatic searching for parents", > + " if incremental streams are received.", > "-C|--chroot confine the process to using chroot", > "--max-errors Terminate as soon as N errors happened while", > " processing commands from the send stream.", >