b7b03eb614
Allow multifd to open file-backed channels. This will be used when enabling the mapped-ram migration stream format which expects a seekable transport. The QIOChannel read and write methods will use the preadv/pwritev versions which don't update the file offset at each call so we can reuse the fd without re-opening for every channel. Contrary to the socket migration, the file migration doesn't need an asynchronous channel creation process, so expose multifd_channel_connect() and call it directly. Note that this is just setup code and multifd cannot yet make use of the file channels. Signed-off-by: Fabiano Rosas <farosas@suse.de> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20240229153017.2221-18-farosas@suse.de Signed-off-by: Peter Xu <peterx@redhat.com>
134 lines
3.5 KiB
C
134 lines
3.5 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 "exec/ramblock.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 "multifd.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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static struct FileOutgoingArgs {
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char *fname;
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} outgoing_args;
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/* Remove the offset option from @filespec and return it in @offsetp. */
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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_cleanup_outgoing_migration(void)
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{
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g_free(outgoing_args.fname);
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outgoing_args.fname = NULL;
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}
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bool file_send_channel_create(gpointer opaque, Error **errp)
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{
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QIOChannelFile *ioc;
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int flags = O_WRONLY;
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bool ret = true;
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ioc = qio_channel_file_new_path(outgoing_args.fname, flags, 0, errp);
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if (!ioc) {
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ret = false;
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goto out;
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}
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multifd_channel_connect(opaque, QIO_CHANNEL(ioc));
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out:
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/*
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* File channel creation is synchronous. However posting this
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* semaphore here is simpler than adding a special case.
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*/
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multifd_send_channel_created();
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return ret;
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}
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void file_start_outgoing_migration(MigrationState *s,
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FileMigrationArgs *file_args, Error **errp)
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{
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g_autoptr(QIOChannelFile) fioc = NULL;
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g_autofree char *filename = g_strdup(file_args->filename);
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uint64_t offset = file_args->offset;
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QIOChannel *ioc;
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trace_migration_file_outgoing(filename);
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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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outgoing_args.fname = g_strdup(filename);
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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(FileMigrationArgs *file_args, Error **errp)
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{
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g_autofree char *filename = g_strdup(file_args->filename);
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QIOChannelFile *fioc = NULL;
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uint64_t offset = file_args->offset;
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QIOChannel *ioc;
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trace_migration_file_incoming(filename);
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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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