migration: Fix iocs leaks during file and fd migration
The memory for the io channels is being leaked in three different ways
during file migration:
1) if the offset check fails we never drop the ioc reference;
2) we allocate an extra channel for no reason;
3) if multifd is enabled but channel creation fails when calling
dup(), we leave the previous channels around along with the glib
polling;
Fix all issues by restructuring the code to first allocate the
channels and only register the watches when all channels have been
created.
For multifd, the file and fd migrations can share code because both
are backed by a QIOChannelFile. For the non-multifd case, the fd needs
to be separate because it is backed by a QIOChannelSocket.
Fixes: 2dd7ee7a51 ("migration/multifd: Add incoming QIOChannelFile support")
Fixes: decdc76772 ("migration/multifd: Add mapped-ram support to fd: URI")
Reported-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240313212824.16974-2-farosas@suse.de
Signed-off-by: Peter Xu <peterx@redhat.com>
diff --git a/migration/file.c b/migration/file.c
index e56c5eb..ddde0ca 100644
--- a/migration/file.c
+++ b/migration/file.c
@@ -115,13 +115,46 @@
return G_SOURCE_REMOVE;
}
+void file_create_incoming_channels(QIOChannel *ioc, Error **errp)
+{
+ int i, fd, channels = 1;
+ g_autofree QIOChannel **iocs = NULL;
+
+ if (migrate_multifd()) {
+ channels += migrate_multifd_channels();
+ }
+
+ iocs = g_new0(QIOChannel *, channels);
+ fd = QIO_CHANNEL_FILE(ioc)->fd;
+ iocs[0] = ioc;
+
+ for (i = 1; i < channels; i++) {
+ QIOChannelFile *fioc = qio_channel_file_new_dupfd(fd, errp);
+
+ if (!fioc) {
+ while (i) {
+ object_unref(iocs[--i]);
+ }
+ return;
+ }
+
+ iocs[i] = QIO_CHANNEL(fioc);
+ }
+
+ for (i = 0; i < channels; i++) {
+ qio_channel_set_name(iocs[i], "migration-file-incoming");
+ qio_channel_add_watch_full(iocs[i], G_IO_IN,
+ file_accept_incoming_migration,
+ NULL, NULL,
+ g_main_context_get_thread_default());
+ }
+}
+
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;
- int channels = 1;
- int i = 0;
trace_migration_file_incoming(filename);
@@ -132,28 +165,11 @@
if (offset &&
qio_channel_io_seek(QIO_CHANNEL(fioc), offset, SEEK_SET, errp) < 0) {
+ object_unref(OBJECT(fioc));
return;
}
- if (migrate_multifd()) {
- channels += migrate_multifd_channels();
- }
-
- 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_dupfd(fioc->fd, errp);
-
- if (!fioc) {
- break;
- }
- } while (++i < channels);
+ file_create_incoming_channels(QIO_CHANNEL(fioc), errp);
}
int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov,
