Re: [PATCH v2 20/29] migration/multifd: Add incoming QIOChannelFile support

[Daniel P . Berrangé]

On Mon, Oct 23, 2023 at 05:35:59PM -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 <farosas@suse.de>
> ---
>  migration/file.c      | 39 +++++++++++++++++++++++++++++----------
>  migration/migration.c |  2 ++
>  migration/multifd.c   |  7 ++++++-
>  migration/multifd.h   |  1 +
>  4 files changed, 38 insertions(+), 11 deletions(-)
> 
> diff --git a/migration/file.c b/migration/file.c
> index 93b9b7bf5d..ad75225f43 100644
> --- a/migration/file.c
> +++ b/migration/file.c
> @@ -6,13 +6,15 @@
>   */
>  
>  #include "qemu/osdep.h"
> -#include "qemu/cutils.h"
>  #include "qapi/error.h"
> +#include "qemu/cutils.h"
> +#include "qemu/error-report.h"
>  #include "channel.h"
>  #include "file.h"
>  #include "migration.h"
>  #include "io/channel-file.h"
>  #include "io/channel-util.h"
> +#include "options.h"
>  #include "trace.h"
>  
>  #define OFFSET_OPTION ",offset="
> @@ -136,7 +138,8 @@ void file_start_incoming_migration(const char *filespec, 
> Error **errp)
>      g_autofree char *filename = g_strdup(filespec);
>      QIOChannelFile *fioc = NULL;
>      uint64_t offset = 0;
> -    QIOChannel *ioc;
> +    int channels = 1;
> +    int i = 0, fd;
>  
>      trace_migration_file_incoming(filename);
>  
> @@ -146,16 +149,32 @@ void file_start_incoming_migration(const char 
> *filespec, Error **errp)
>  
>      fioc = qio_channel_file_new_path(filename, O_RDONLY, 0, errp);
>      if (!fioc) {
> -        return;
> +        goto out;
> +    }
> +
> +    if (migrate_multifd()) {
> +        channels += migrate_multifd_channels();
>      }
>  
> -    ioc = QIO_CHANNEL(fioc);
> -    if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
> +    fd = fioc->fd;
> +
> +    do {
> +        QIOChannel *ioc = QIO_CHANNEL(fioc);
> +
> +        if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
> +            return;
> +        }
> +
> +        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)));

IIUC, this loop is failing to call qio_channel_io_seek to set
the offset on the last 'fioc' that is created.


With regards,
Daniel
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