On Mon, Mar 11, 2024 at 12:03:41PM +0000, Daniel P. Berrangé wrote:
> On Mon, Mar 04, 2024 at 09:26:32AM +0800, pet...@redhat.com wrote:
> > From: Fabiano Rosas <faro...@suse.de>
> >
> > If we receive a file descriptor that points to a regular file, there's
> > nothing stopping us from doing multifd migration with mapped-ram to
> > that file.
> >
> > Enable the fd: URI to work with multifd + mapped-ram.
> >
> > Note that the fds passed into multifd are duplicated because we want
> > to avoid cross-thread effects when doing cleanup (i.e. close(fd)). The
> > original fd doesn't need to be duplicated because monitor_get_fd()
> > transfers ownership to the caller.
> >
> > Signed-off-by: Fabiano Rosas <faro...@suse.de>
> > Reviewed-by: Peter Xu <pet...@redhat.com>
> > Link: https://lore.kernel.org/r/20240229153017.2221-23-faro...@suse.de
> > Signed-off-by: Peter Xu <pet...@redhat.com>
> > ---
> > migration/fd.h | 2 ++
> > migration/fd.c | 44 +++++++++++++++++++++++++++++++++++++++++++
> > migration/file.c | 18 ++++++++++++------
> > migration/migration.c | 4 ++++
> > migration/multifd.c | 2 ++
> > 5 files changed, 64 insertions(+), 6 deletions(-)
> >
>
> > @@ -73,4 +98,23 @@ void fd_start_incoming_migration(const char *fdname,
> > Error **errp)
> > fd_accept_incoming_migration,
> > NULL, NULL,
> > g_main_context_get_thread_default());
> > +
> > + if (migrate_multifd()) {
> > + int channels = migrate_multifd_channels();
> > +
> > + while (channels--) {
> > + ioc = QIO_CHANNEL(qio_channel_file_new_fd(dup(fd)));
> > +
> > + if (QIO_CHANNEL_FILE(ioc)->fd == -1) {
> > + error_setg(errp, "Failed to duplicate fd %d", fd);
> > + return;
> > + }
>
> I'd suggest that Peter's comment about failure checks be fixed
> by introducing a new constructor that handles the dup + error
> reporting.
>
> QIOChannel *qio_channel_file_new_dupfd(int fd, Error **errp;)
>
> so we're not repeating the error reporting multiple places.
Indeed that looks cleaner.
At the meantime, I just noticed there seems to have an IOC leak on incoming
side.. file_start_incoming_migration():
do {
QIOChannel *ioc = QIO_CHANNEL(fioc);
qio_channel_set_name(ioc, "migration-file-incoming");
qio_channel_add_watch_full(ioc, G_IO_IN,
file_accept_incoming_migration,
NULL, NULL,
g_main_context_get_thread_default());
fioc = qio_channel_file_new_fd(dup(fioc->fd)); <--------------------
here
if (!fioc || fioc->fd == -1) {
error_setg(errp, "Error creating migration incoming channel");
break;
}
} while (++i < channels);
Fabiano, would you send patches to address these issues (split if both
issues exist)?
Thanks,
--
Peter Xu
