385f510df5
Allow an offset option to be specified as part of the file URI, in the form "file:filename,offset=offset", where offset accepts the common size suffixes, or the 0x prefix, but not both. Migration data is written to and read from the file starting at offset. If unspecified, it defaults to 0. This is needed by libvirt to store its own data at the head of the file. Suggested-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Message-ID: <1694182931-61390-3-git-send-email-steven.sistare@oracle.com>
104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
/*
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* Copyright (c) 2021-2023 Oracle and/or its affiliates.
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "qemu/cutils.h"
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#include "qapi/error.h"
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#include "channel.h"
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#include "file.h"
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#include "migration.h"
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#include "io/channel-file.h"
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#include "io/channel-util.h"
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#include "trace.h"
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#define OFFSET_OPTION ",offset="
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/* Remove the offset option from @filespec and return it in @offsetp. */
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static int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp)
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{
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char *option = strstr(filespec, OFFSET_OPTION);
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int ret;
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if (option) {
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*option = 0;
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option += sizeof(OFFSET_OPTION) - 1;
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ret = qemu_strtosz(option, NULL, offsetp);
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if (ret) {
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error_setg_errno(errp, -ret, "file URI has bad offset %s", option);
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return -1;
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}
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}
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return 0;
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}
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void file_start_outgoing_migration(MigrationState *s, const char *filespec,
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Error **errp)
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{
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g_autofree char *filename = g_strdup(filespec);
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g_autoptr(QIOChannelFile) fioc = NULL;
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uint64_t offset = 0;
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QIOChannel *ioc;
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trace_migration_file_outgoing(filename);
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if (file_parse_offset(filename, &offset, errp)) {
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return;
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}
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fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC,
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0600, errp);
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if (!fioc) {
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return;
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}
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ioc = QIO_CHANNEL(fioc);
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if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
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return;
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}
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qio_channel_set_name(ioc, "migration-file-outgoing");
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migration_channel_connect(s, ioc, NULL, NULL);
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}
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static gboolean file_accept_incoming_migration(QIOChannel *ioc,
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GIOCondition condition,
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gpointer opaque)
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{
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migration_channel_process_incoming(ioc);
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object_unref(OBJECT(ioc));
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return G_SOURCE_REMOVE;
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}
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void file_start_incoming_migration(const char *filespec, Error **errp)
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{
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g_autofree char *filename = g_strdup(filespec);
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QIOChannelFile *fioc = NULL;
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uint64_t offset = 0;
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QIOChannel *ioc;
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trace_migration_file_incoming(filename);
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if (file_parse_offset(filename, &offset, errp)) {
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return;
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}
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fioc = qio_channel_file_new_path(filename, O_RDONLY, 0, errp);
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if (!fioc) {
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return;
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}
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ioc = QIO_CHANNEL(fioc);
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if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
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return;
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}
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qio_channel_set_name(QIO_CHANNEL(ioc), "migration-file-incoming");
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qio_channel_add_watch_full(ioc, G_IO_IN,
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file_accept_incoming_migration,
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NULL, NULL,
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g_main_context_get_thread_default());
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}
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