migration/file.c

   1 /*
   2  * Copyright (c) 2021-2023 Oracle and/or its affiliates.
   3  *
   4  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   5  * See the COPYING file in the top-level directory.
   6  */
   7
   8 #include "qemu/osdep.h"
   9 #include "qemu/cutils.h"
  10 #include "qapi/error.h"
  11 #include "channel.h"
  12 #include "file.h"
  13 #include "migration.h"
  14 #include "io/channel-file.h"
  15 #include "io/channel-util.h"
  16 #include "trace.h"
  17
  18 #define OFFSET_OPTION ",offset="
  19
  20 /* Remove the offset option from @filespec and return it in @offsetp. */
  21
  22 static int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp)
  23 {
  24     char *option = strstr(filespec, OFFSET_OPTION);
  25     int ret;
  26
  27     if (option) {
  28         *option = 0;
  29         option += sizeof(OFFSET_OPTION) - 1;
  30         ret = qemu_strtosz(option, NULL, offsetp);
  31         if (ret) {
  32             error_setg_errno(errp, -ret, "file URI has bad offset %s", option);
  33             return -1;
  34         }
  35     }
  36     return 0;
  37 }
  38
  39 void file_start_outgoing_migration(MigrationState *s, const char *filespec,
  40                                    Error **errp)
  41 {
  42     g_autofree char *filename = g_strdup(filespec);
  43     g_autoptr(QIOChannelFile) fioc = NULL;
  44     uint64_t offset = 0;
  45     QIOChannel *ioc;
  46
  47     trace_migration_file_outgoing(filename);
  48
  49     if (file_parse_offset(filename, &offset, errp)) {
  50         return;
  51     }
  52
  53     fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC,
  54                                      0600, errp);
  55     if (!fioc) {
  56         return;
  57     }
  58
  59     ioc = QIO_CHANNEL(fioc);
  60     if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
  61         return;
  62     }
  63     qio_channel_set_name(ioc, "migration-file-outgoing");
  64     migration_channel_connect(s, ioc, NULL, NULL);
  65 }
  66
  67 static gboolean file_accept_incoming_migration(QIOChannel *ioc,
  68                                                GIOCondition condition,
  69                                                gpointer opaque)
  70 {
  71     migration_channel_process_incoming(ioc);
  72     object_unref(OBJECT(ioc));
  73     return G_SOURCE_REMOVE;
  74 }
  75
  76 void file_start_incoming_migration(const char *filespec, Error **errp)
  77 {
  78     g_autofree char *filename = g_strdup(filespec);
  79     QIOChannelFile *fioc = NULL;
  80     uint64_t offset = 0;
  81     QIOChannel *ioc;
  82
  83     trace_migration_file_incoming(filename);
  84
  85     if (file_parse_offset(filename, &offset, errp)) {
  86         return;
  87     }
  88
  89     fioc = qio_channel_file_new_path(filename, O_RDONLY, 0, errp);
  90     if (!fioc) {
  91         return;
  92     }
  93
  94     ioc = QIO_CHANNEL(fioc);
  95     if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
  96         return;
  97     }
  98     qio_channel_set_name(QIO_CHANNEL(ioc), "migration-file-incoming");
  99     qio_channel_add_watch_full(ioc, G_IO_IN,
 100                                file_accept_incoming_migration,
 101                                NULL, NULL,
 102                                g_main_context_get_thread_default());
 103 }