block/nfs: fix mutex assertion in nfs_file_close()

Commit c096358e74 introduced assertion
checks for when qemu_mutex() functions are called without the
corresponding qemu_mutex_init() having initialized the mutex.

This uncovered a latent bug in qemu's nfs driver - in
nfs_client_close(), the NFSClient structure is overwritten with zeros,
prior to the mutex being destroyed.

Go ahead and destroy the mutex in nfs_client_close(), and change where
we call qemu_mutex_init() so that it is correctly balanced.

There are also a couple of memory leaks obscured by the memset, so this
fixes those as well.

Finally, we should be able to get rid of the memset(), as it isn't
necessary.

Cc: qemu-stable@nongnu.org
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Jeff Cody 2017-08-07 18:29:09 -04:00 committed by Kevin Wolf
parent ea22b7a220
commit 113fe792fd

View File

@ -433,19 +433,23 @@ static void nfs_client_close(NFSClient *client)
if (client->context) {
if (client->fh) {
nfs_close(client->context, client->fh);
client->fh = NULL;
}
aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
false, NULL, NULL, NULL, NULL);
nfs_destroy_context(client->context);
client->context = NULL;
}
memset(client, 0, sizeof(NFSClient));
g_free(client->path);
qemu_mutex_destroy(&client->mutex);
qapi_free_NFSServer(client->server);
client->server = NULL;
}
static void nfs_file_close(BlockDriverState *bs)
{
NFSClient *client = bs->opaque;
nfs_client_close(client);
qemu_mutex_destroy(&client->mutex);
}
static NFSServer *nfs_config(QDict *options, Error **errp)
@ -498,6 +502,7 @@ static int64_t nfs_client_open(NFSClient *client, QDict *options,
struct stat st;
char *file = NULL, *strp = NULL;
qemu_mutex_init(&client->mutex);
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
qemu_opts_absorb_qdict(opts, options, &local_err);
if (local_err) {
@ -660,7 +665,7 @@ static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
if (ret < 0) {
return ret;
}
qemu_mutex_init(&client->mutex);
bs->total_sectors = ret;
ret = 0;
return ret;