On Mon, Feb 26, 2024 at 03:34:26PM +0800, Peter Xu wrote: > On Tue, Feb 20, 2024 at 07:41:25PM -0300, Fabiano Rosas wrote: > > On the receiving side we don't need to differentiate between main > > channel and threads, so whichever channel is defined first gets to be > > the main one. And since there are no packets, use the atomic channel > > count to index into the params array. > > > > Signed-off-by: Fabiano Rosas <faro...@suse.de> > > --- > > migration/file.c | 34 ++++++++++++++++++++++++++-------- > > migration/migration.c | 3 ++- > > migration/multifd.c | 3 +-- > > 3 files changed, 29 insertions(+), 11 deletions(-) > > > > diff --git a/migration/file.c b/migration/file.c > > index ac9f6ae40a..a186dc592a 100644 > > --- a/migration/file.c > > +++ b/migration/file.c > > @@ -8,6 +8,7 @@ > > #include "qemu/osdep.h" > > #include "exec/ramblock.h" > > #include "qemu/cutils.h" > > +#include "qemu/error-report.h" > > #include "qapi/error.h" > > #include "channel.h" > > #include "file.h" > > @@ -15,6 +16,7 @@ > > #include "multifd.h" > > #include "io/channel-file.h" > > #include "io/channel-util.h" > > +#include "options.h" > > #include "trace.h" > > > > #define OFFSET_OPTION ",offset=" > > @@ -111,7 +113,8 @@ void file_start_incoming_migration(FileMigrationArgs > > *file_args, Error **errp) > > g_autofree char *filename = g_strdup(file_args->filename); > > QIOChannelFile *fioc = NULL; > > uint64_t offset = file_args->offset; > > - QIOChannel *ioc; > > + int channels = 1; > > + int i = 0, fd; > > > > trace_migration_file_incoming(filename); > > > > @@ -120,13 +123,28 @@ void file_start_incoming_migration(FileMigrationArgs > > *file_args, Error **errp) > > return; > > } > > > > - ioc = QIO_CHANNEL(fioc); > > - if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) { > > + if (offset && > > + qio_channel_io_seek(QIO_CHANNEL(fioc), offset, SEEK_SET, errp) < > > 0) { > > return; > > } > > - qio_channel_set_name(QIO_CHANNEL(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()); > > + > > + if (migrate_multifd()) { > > + channels += migrate_multifd_channels(); > > + } > > + > > + fd = fioc->fd; > > + > > + 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()); > > + } while (++i < channels && (fioc = qio_channel_file_new_fd(fd))); > > Note that reusing fd here has similar risk in the future that one iochannel > can affect the other, as potentially all shares the same fd underneath; I > think it's the same as "two qemufile v.s. one iochannel" issue that we're > fighting recently. > > IIUC the clean case is still that we open one fd for each iochannel. Or > e.g. as long as one iochannel close() its fd, it immediately invalidates > all the rest iochannels on something like use-after-free of that fd index; > any fd operates races with another fd being opened concurrently. > > Maybe we can already use a loop of qio_channel_file_new_path()? OS should > already cached the dentry etc. so I assume the following ones should be > super fast? Or there's other complexities that I didn't aware?
Or simply use dup()? > > > + > > + if (!fioc) { > > + error_setg(errp, "Error creating migration incoming channel"); > > + } > > } > > diff --git a/migration/migration.c b/migration/migration.c > > index 16da269847..e2218b9de7 100644 > > --- a/migration/migration.c > > +++ b/migration/migration.c > > @@ -896,7 +896,8 @@ void migration_ioc_process_incoming(QIOChannel *ioc, > > Error **errp) > > uint32_t channel_magic = 0; > > int ret = 0; > > > > - if (migrate_multifd() && !migrate_postcopy_ram() && > > + if (migrate_multifd() && !migrate_fixed_ram() && > > + !migrate_postcopy_ram() && > > qio_channel_has_feature(ioc, QIO_CHANNEL_FEATURE_READ_MSG_PEEK)) { > > /* > > * With multiple channels, it is possible that we receive channels > > diff --git a/migration/multifd.c b/migration/multifd.c > > index 507b497d52..cb5f4fb3e0 100644 > > --- a/migration/multifd.c > > +++ b/migration/multifd.c > > @@ -1520,8 +1520,7 @@ void multifd_recv_new_channel(QIOChannel *ioc, Error > > **errp) > > } > > trace_multifd_recv_new_channel(id); > > } else { > > - /* next patch gives this a meaningful value */ > > - id = 0; > > + id = qatomic_read(&multifd_recv_state->count); > > } > > > > p = &multifd_recv_state->params[id]; > > -- > > 2.35.3 > > > > -- > Peter Xu -- Peter Xu