backup: improve error when copy-before-write fails for fleecing

[pve-qemu.git] / debian / patches / pve / 0031-PVE-Backup-pbs-restore-new-command-to-restore-from-p.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Dietmar Maurer <dietmar@proxmox.com>
Date: Mon, 6 Apr 2020 12:17:01 +0200
Subject: [PATCH] PVE-Backup: pbs-restore - new command to restore from proxmox
 backup server

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
[WB: add namespace support]
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
 meson.build   |   4 +
 pbs-restore.c | 236 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 240 insertions(+)
 create mode 100644 pbs-restore.c

diff --git a/meson.build b/meson.build
index d16b97cf3c..6de51c34cb 100644
--- a/meson.build
+++ b/meson.build
@@ -4029,6 +4029,10 @@ if have_tools
   vma = executable('vma', files('vma.c', 'vma-reader.c') + genh,
                    dependencies: [authz, block, crypto, io, qom], install: true)
 
+  pbs_restore = executable('pbs-restore', files('pbs-restore.c') + genh,
+                  dependencies: [authz, block, crypto, io, qom,
+                    libproxmox_backup_qemu], install: true)
+
   subdir('storage-daemon')
 
   foreach exe: [ 'qemu-img', 'qemu-io', 'qemu-nbd', 'qemu-storage-daemon']
diff --git a/pbs-restore.c b/pbs-restore.c
new file mode 100644
index 0000000000..f03d9bab8d
--- /dev/null
+++ b/pbs-restore.c
@@ -0,0 +1,236 @@
+/*
+ * Qemu image restore helper for Proxmox Backup
+ *
+ * Copyright (C) 2019 Proxmox Server Solutions
+ *
+ * Authors:
+ *  Dietmar Maurer (dietmar@proxmox.com)
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include <glib.h>
+#include <getopt.h>
+#include <string.h>
+
+#include "qemu/module.h"
+#include "qemu/error-report.h"
+#include "qemu/main-loop.h"
+#include "qemu/cutils.h"
+#include "qapi/error.h"
+#include "qapi/qmp/qdict.h"
+#include "sysemu/block-backend.h"
+
+#include <proxmox-backup-qemu.h>
+
+static void help(void)
+{
+    const char *help_msg =
+        "usage: pbs-restore [--repository <repo>] [--ns namespace] snapshot archive-name target [command options]\n"
+        ;
+
+    printf("%s", help_msg);
+    exit(1);
+}
+
+typedef struct CallbackData {
+    BlockBackend *target;
+    uint64_t last_offset;
+    bool skip_zero;
+} CallbackData;
+
+static int write_callback(
+    void *callback_data_ptr,
+    uint64_t offset,
+    const unsigned char *data,
+    uint64_t data_len)
+{
+    int res = -1;
+
+    CallbackData *callback_data = (CallbackData *)callback_data_ptr;
+
+    uint64_t last_offset = callback_data->last_offset;
+    if (offset > last_offset) callback_data->last_offset = offset;
+
+    if (data == NULL) {
+        if (callback_data->skip_zero && offset > last_offset) {
+            return 0;
+        }
+        res = blk_pwrite_zeroes(callback_data->target, offset, data_len, 0);
+    } else {
+        res = blk_pwrite(callback_data->target, offset, data_len, data, 0);
+    }
+
+    if (res < 0) {
+        fprintf(stderr, "blk_pwrite failed at offset %ld length %ld (%d) - %s\n", offset, data_len, res, strerror(-res));
+        return res;
+    }
+
+    return 0;
+}
+
+int main(int argc, char **argv)
+{
+    Error *main_loop_err = NULL;
+    const char *format = "raw";
+    const char *repository = NULL;
+    const char *backup_ns = NULL;
+    const char *keyfile = NULL;
+    int verbose = false;
+    bool skip_zero = false;
+
+    error_init(argv[0]);
+
+    for (;;) {
+        static const struct option long_options[] = {
+            {"help", no_argument, 0, 'h'},
+            {"skip-zero", no_argument, 0, 'S'},
+            {"verbose", no_argument, 0, 'v'},
+            {"format", required_argument, 0, 'f'},
+            {"repository", required_argument, 0, 'r'},
+            {"ns", required_argument, 0, 'n'},
+            {"keyfile", required_argument, 0, 'k'},
+            {0, 0, 0, 0}
+        };
+        int c = getopt_long(argc, argv, "hvf:r:k:", long_options, NULL);
+        if (c == -1) {
+            break;
+        }
+        switch (c) {
+            case ':':
+                fprintf(stderr, "missing argument for option '%s'\n", argv[optind - 1]);
+                return -1;
+            case '?':
+                fprintf(stderr, "unrecognized option '%s'\n", argv[optind - 1]);
+                return -1;
+            case 'f':
+                format = g_strdup(argv[optind - 1]);
+                break;
+            case 'r':
+                repository = g_strdup(argv[optind - 1]);
+                break;
+            case 'n':
+                backup_ns = g_strdup(argv[optind - 1]);
+                break;
+            case 'k':
+                keyfile = g_strdup(argv[optind - 1]);
+                break;
+            case 'v':
+                verbose = true;
+                break;
+            case 'S':
+                skip_zero = true;
+                break;
+            case 'h':
+                help();
+                return 0;
+        }
+    }
+
+    if (optind >= argc - 2) {
+        fprintf(stderr, "missing arguments\n");
+        help();
+        return -1;
+    }
+
+    if (repository == NULL) {
+        repository = getenv("PBS_REPOSITORY");
+    }
+
+    if (repository == NULL) {
+        fprintf(stderr, "no repository specified\n");
+        help();
+        return -1;
+    }
+
+    char *snapshot = argv[optind++];
+    char *archive_name = argv[optind++];
+    char *target = argv[optind++];
+
+    const char *password = getenv("PBS_PASSWORD");
+    const char *fingerprint = getenv("PBS_FINGERPRINT");
+    const char *key_password = getenv("PBS_ENCRYPTION_PASSWORD");
+
+    if (qemu_init_main_loop(&main_loop_err)) {
+        g_error("%s", error_get_pretty(main_loop_err));
+    }
+
+    bdrv_init();
+    module_call_init(MODULE_INIT_QOM);
+
+    if (verbose) {
+        fprintf(stderr, "connecting to repository '%s'\n", repository);
+    }
+    char *pbs_error = NULL;
+    ProxmoxRestoreHandle *conn = proxmox_restore_new_ns(
+        repository,
+        snapshot,
+        backup_ns,
+        password,
+        keyfile,
+        key_password,
+        fingerprint,
+        &pbs_error
+    );
+    if (conn == NULL) {
+        fprintf(stderr, "restore failed: %s\n", pbs_error);
+        return -1;
+    }
+
+    int res = proxmox_restore_connect(conn, &pbs_error);
+    if (res < 0 || pbs_error) {
+        fprintf(stderr, "restore failed (connection error): %s\n", pbs_error);
+        return -1;
+    }
+
+    QDict *options = qdict_new();
+
+    if (format) {
+        qdict_put_str(options, "driver", format);
+    }
+
+
+    if (verbose) {
+        fprintf(stderr, "open block backend for target '%s'\n", target);
+    }
+    Error *local_err = NULL;
+    int flags = BDRV_O_RDWR;
+    BlockBackend *blk = blk_new_open(target, NULL, options, flags, &local_err);
+    if (!blk) {
+        fprintf(stderr, "%s\n", error_get_pretty(local_err));
+        return -1;
+    }
+
+    CallbackData *callback_data = calloc(sizeof(CallbackData), 1);
+
+    callback_data->target = blk;
+    callback_data->skip_zero = skip_zero;
+    callback_data->last_offset = 0;
+
+    // blk_set_enable_write_cache(blk, !writethrough);
+
+    if (verbose) {
+        fprintf(stderr, "starting to restore snapshot '%s'\n", snapshot);
+        fflush(stderr); // ensure we do not get printed after the progress log
+    }
+    res = proxmox_restore_image(
+        conn,
+        archive_name,
+        write_callback,
+        callback_data,
+        &pbs_error,
+        verbose);
+
+    proxmox_restore_disconnect(conn);
+    blk_unref(blk);
+
+    if (res < 0) {
+        fprintf(stderr, "restore failed: %s\n", pbs_error);
+        return -1;
+    }
+
+    return 0;
+}