From 74228c598f139bd9ce7839794be9a3ccc180fb27 Mon Sep 17 00:00:00 2001 From: Fabiano Rosas Date: Wed, 13 Mar 2024 18:28:23 -0300 Subject: [PATCH] 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 Signed-off-by: Fabiano Rosas Link: https://lore.kernel.org/r/20240313212824.16974-2-farosas@suse.de Signed-off-by: Peter Xu --- migration/fd.c | 29 +++++++----------------- migration/file.c | 58 ++++++++++++++++++++++++++++++------------------ migration/file.h | 1 + 3 files changed, 46 insertions(+), 42 deletions(-) diff --git a/migration/fd.c b/migration/fd.c index 4e2a63a73d..39a52e5c90 100644 --- a/migration/fd.c +++ b/migration/fd.c @@ -18,6 +18,7 @@ #include "qapi/error.h" #include "channel.h" #include "fd.h" +#include "file.h" #include "migration.h" #include "monitor/monitor.h" #include "io/channel-file.h" @@ -80,7 +81,6 @@ static gboolean fd_accept_incoming_migration(QIOChannel *ioc, void fd_start_incoming_migration(const char *fdname, Error **errp) { QIOChannel *ioc; - QIOChannelFile *fioc; int fd = monitor_fd_param(monitor_cur(), fdname, errp); if (fd == -1) { return; @@ -94,26 +94,13 @@ void fd_start_incoming_migration(const char *fdname, Error **errp) return; } - qio_channel_set_name(ioc, "migration-fd-incoming"); - qio_channel_add_watch_full(ioc, G_IO_IN, - fd_accept_incoming_migration, - NULL, NULL, - g_main_context_get_thread_default()); - if (migrate_multifd()) { - int channels = migrate_multifd_channels(); - - while (channels--) { - fioc = qio_channel_file_new_dupfd(fd, errp); - if (!fioc) { - return; - } - - qio_channel_set_name(ioc, "migration-fd-incoming"); - qio_channel_add_watch_full(QIO_CHANNEL(fioc), G_IO_IN, - fd_accept_incoming_migration, - NULL, NULL, - g_main_context_get_thread_default()); - } + file_create_incoming_channels(ioc, errp); + } else { + qio_channel_set_name(ioc, "migration-fd-incoming"); + qio_channel_add_watch_full(ioc, G_IO_IN, + fd_accept_incoming_migration, + NULL, NULL, + g_main_context_get_thread_default()); } } diff --git a/migration/file.c b/migration/file.c index e56c5eb0a5..ddde0ca818 100644 --- a/migration/file.c +++ b/migration/file.c @@ -115,13 +115,46 @@ static gboolean file_accept_incoming_migration(QIOChannel *ioc, 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 @@ void file_start_incoming_migration(FileMigrationArgs *file_args, Error **errp) 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, diff --git a/migration/file.h b/migration/file.h index 9f71e87f74..7699c04677 100644 --- a/migration/file.h +++ b/migration/file.h @@ -20,6 +20,7 @@ void file_start_outgoing_migration(MigrationState *s, int file_parse_offset(char *filespec, uint64_t *offsetp, Error **errp); void file_cleanup_outgoing_migration(void); bool file_send_channel_create(gpointer opaque, Error **errp); +void file_create_incoming_channels(QIOChannel *ioc, Error **errp); int file_write_ramblock_iov(QIOChannel *ioc, const struct iovec *iov, int niov, RAMBlock *block, Error **errp); int multifd_file_recv_data(MultiFDRecvParams *p, Error **errp);