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migration: clean up xbzrle cache init/destroy

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Let's further simplify ram_init_all() and ram_save_cleanup() by abstract
all the XBZRLE related codes into their own functions.

When allocating xbzrle cache, we are always very careful on -ENOMEM;
which makes sense.  Replacing the last g_malloc0() with g_try_malloc0(),
then refactor the logic a bit.

This patch should be fixing some memory leaks when some memory
allocation failed for XBZRLE in the past.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Peter Xu 2017-10-19 14:31:59 +08:00 committed by Juan Quintela
parent 7d7c96be7b
commit 84593a0807
1 changed files with 77 additions and 46 deletions
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121
migration/ram.c
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@ -1585,6 +1585,22 @@ static void ram_state_cleanup(RAMState **rsp)
*rsp = NULL;
}
static void xbzrle_cleanup(void)
{
XBZRLE_cache_lock();
if (XBZRLE.cache) {
cache_fini(XBZRLE.cache);
g_free(XBZRLE.encoded_buf);
g_free(XBZRLE.current_buf);
g_free(XBZRLE.zero_target_page);
XBZRLE.cache = NULL;
XBZRLE.encoded_buf = NULL;
XBZRLE.current_buf = NULL;
XBZRLE.zero_target_page = NULL;
}
XBZRLE_cache_unlock();
}
static void ram_save_cleanup(void *opaque)
{
RAMState **rsp = opaque;
@ -1602,18 +1618,7 @@ static void ram_save_cleanup(void *opaque)
block->unsentmap = NULL;
}
XBZRLE_cache_lock();
if (XBZRLE.cache) {
cache_fini(XBZRLE.cache);
g_free(XBZRLE.encoded_buf);
g_free(XBZRLE.current_buf);
g_free(XBZRLE.zero_target_page);
XBZRLE.cache = NULL;
XBZRLE.encoded_buf = NULL;
XBZRLE.current_buf = NULL;
XBZRLE.zero_target_page = NULL;
}
XBZRLE_cache_unlock();
xbzrle_cleanup();
compress_threads_save_cleanup();
ram_state_cleanup(rsp);
}
@ -2024,6 +2029,63 @@ err:
return ret;
}
/*
* For every allocation, we will try not to crash the VM if the
* allocation failed.
*/
static int xbzrle_init(void)
{
Error *local_err = NULL;
if (!migrate_use_xbzrle()) {
return 0;
}
XBZRLE_cache_lock();
XBZRLE.zero_target_page = g_try_malloc0(TARGET_PAGE_SIZE);
if (!XBZRLE.zero_target_page) {
error_report("%s: Error allocating zero page", __func__);
goto err_out;
}
XBZRLE.cache = cache_init(migrate_xbzrle_cache_size(),
TARGET_PAGE_SIZE, &local_err);
if (!XBZRLE.cache) {
error_report_err(local_err);
goto free_zero_page;
}
XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
if (!XBZRLE.encoded_buf) {
error_report("%s: Error allocating encoded_buf", __func__);
goto free_cache;
}
XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
if (!XBZRLE.current_buf) {
error_report("%s: Error allocating current_buf", __func__);
goto free_encoded_buf;
}
/* We are all good */
XBZRLE_cache_unlock();
return 0;
free_encoded_buf:
g_free(XBZRLE.encoded_buf);
XBZRLE.encoded_buf = NULL;
free_cache:
cache_fini(XBZRLE.cache);
XBZRLE.cache = NULL;
free_zero_page:
g_free(XBZRLE.zero_target_page);
XBZRLE.zero_target_page = NULL;
err_out:
XBZRLE_cache_unlock();
return -ENOMEM;
}
static int ram_state_init(RAMState **rsp)
{
*rsp = g_try_new0(RAMState, 1);
@ -2050,45 +2112,14 @@ static int ram_state_init(RAMState **rsp)
static int ram_init_all(RAMState **rsp)
{
Error *local_err = NULL;
if (ram_state_init(rsp)) {
return -1;
}
if (migrate_use_xbzrle()) {
XBZRLE_cache_lock();
XBZRLE.zero_target_page = g_malloc0(TARGET_PAGE_SIZE);
XBZRLE.cache = cache_init(migrate_xbzrle_cache_size(),
TARGET_PAGE_SIZE, &local_err);
if (!XBZRLE.cache) {
XBZRLE_cache_unlock();
error_report_err(local_err);
g_free(*rsp);
*rsp = NULL;
if (xbzrle_init()) {
ram_state_cleanup(rsp);
return -1;
}
XBZRLE_cache_unlock();
/* We prefer not to abort if there is no memory */
XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
if (!XBZRLE.encoded_buf) {
error_report("Error allocating encoded_buf");
g_free(*rsp);
*rsp = NULL;
return -1;
}
XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
if (!XBZRLE.current_buf) {
error_report("Error allocating current_buf");
g_free(XBZRLE.encoded_buf);
XBZRLE.encoded_buf = NULL;
g_free(*rsp);
*rsp = NULL;
return -1;
}
}
/* For memory_global_dirty_log_start below. */
qemu_mutex_lock_iothread();