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 <lauri.vosa...@gmail.com>
---
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 <subvol> Disables the automatic searching for parents",
+ " if incremental streams are received.",
"-C|--chroot confine the process to <mount> using chroot",
"--max-errors <N> Terminate as soon as N errors happened while",
" processing commands from the send stream.",
