Btrfs-progs: add send option for using new end-cmd semantic

[platform/upstream/btrfs-progs.git] / cmds-send.c

diff --git a/cmds-send.c b/cmds-send.c
index 0057e6b..72804a9 100644 (file)
--- a/cmds-send.c
+++ b/cmds-send.c
@@ -244,7 +244,8 @@ out:
        return ERR_PTR(ret);
 }
 
-static int do_send(struct btrfs_send *send, u64 root_id, u64 parent_root_id)
+static int do_send(struct btrfs_send *send, u64 root_id, u64 parent_root_id,
+                  int is_first_subvol, int is_last_subvol)
 {
        int ret;
        pthread_t t_read;
@@ -298,11 +299,18 @@ static int do_send(struct btrfs_send *send, u64 root_id, u64 parent_root_id)
        io_send.clone_sources = (__u64*)send->clone_sources;
        io_send.clone_sources_count = send->clone_sources_count;
        io_send.parent_root = parent_root_id;
+       if (!is_first_subvol)
+               io_send.flags |= BTRFS_SEND_FLAG_OMIT_STREAM_HEADER;
+       if (!is_last_subvol)
+               io_send.flags |= BTRFS_SEND_FLAG_OMIT_END_CMD;
        ret = ioctl(subvol_fd, BTRFS_IOC_SEND, &io_send);
        if (ret) {
                ret = -errno;
                fprintf(stderr, "ERROR: send ioctl failed with %d: %s\n", ret,
                        strerror(-ret));
+               if (ret == -EINVAL && (!is_first_subvol || !is_last_subvol))
+                       fprintf(stderr,
+                               "Try upgrading your kernel or don't use -e.\n");
                goto out;
        }
        if (g_verbose > 0)
@@ -435,15 +443,19 @@ int cmd_send_start(int argc, char **argv)
        u64 root_id;
        u64 parent_root_id = 0;
        int full_send = 1;
+       int new_end_cmd_semantic = 0;
 
        memset(&send, 0, sizeof(send));
        send.dump_fd = fileno(stdout);
 
-       while ((c = getopt(argc, argv, "vc:f:i:p:")) != -1) {
+       while ((c = getopt(argc, argv, "vec:f:i:p:")) != -1) {
                switch (c) {
                case 'v':
                        g_verbose++;
                        break;
+               case 'e':
+                       new_end_cmd_semantic = 1;
+                       break;
                case 'c':
                        subvol = realpath(optarg, NULL);
                        if (!subvol) {
@@ -594,6 +606,9 @@ int cmd_send_start(int argc, char **argv)
        }
 
        for (i = optind; i < argc; i++) {
+               int is_first_subvol;
+               int is_last_subvol;
+
                free(subvol);
                subvol = argv[i];
 
@@ -634,7 +649,17 @@ int cmd_send_start(int argc, char **argv)
                        goto out;
                }
 
-               ret = do_send(&send, root_id, parent_root_id);
+               if (new_end_cmd_semantic) {
+                       /* require new kernel */
+                       is_first_subvol = (i == optind);
+                       is_last_subvol = (i == argc - 1);
+               } else {
+                       /* be compatible to old and new kernel */
+                       is_first_subvol = 1;
+                       is_last_subvol = 1;
+               }
+               ret = do_send(&send, root_id, parent_root_id,
+                             is_first_subvol, is_last_subvol);
                if (ret < 0)
                        goto out;
 
@@ -664,7 +689,7 @@ static const char * const send_cmd_group_usage[] = {
 };
 
 const char * const cmd_send_usage[] = {
-       "btrfs send [-v] [-p <parent>] [-c <clone-src>] <subvol>",
+       "btrfs send [-ve] [-p <parent>] [-c <clone-src>] <subvol>",
        "Send the subvolume to stdout.",
        "Sends the subvolume specified by <subvol> to stdout.",
        "By default, this will send the whole subvolume. To do an incremental",
@@ -679,6 +704,8 @@ const char * const cmd_send_usage[] = {
        "\n",
        "-v               Enable verbose debug output. Each occurrence of",
        "                 this option increases the verbose level more.",
+       "-e               If sending multiple subvols at once, use the new",
+       "                 format and omit the end-cmd between the subvols.",
        "-p <parent>      Send an incremental stream from <parent> to",
        "                 <subvol>.",
        "-c <clone-src>   Use this snapshot as a clone source for an ",