bytemark/flexnbd-c
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Quit with an error status on SIGTERM during migration

Browse Source 
This prevents the supervisor from thinking that the migration completed
successfully.

In order to do this, I've introduced a new lock around the start (and
finish) of the migration so that we avoid a race between the signal
handler in the server_accept loop and the control thread mirror startup.
Without that, we'd risk successfully starting a migration after the
SIGTERM handler fired, which would be Bad.
This commit is contained in:
Alex Young
2012-10-04 14:41:55 +01:00
parent ddc57e76d1
commit f3e0d61323
10 changed files with 226 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

82
src/control.c
View File

@@ -361,19 +361,35 @@ int control_mirror(struct control_client* client, int linesc, char** lines)
struct server * serve = flexnbd_server(flexnbd);
if ( serve->mirror_super ) {
warn( "Tried to start a second mirror run" );
write_socket( "1: mirror already running" );
} else {
serve->mirror_super = mirror_super_create(
serve->filename,
connect_to,
connect_from,
max_Bps ,
action_at_finish,
client->mirror_state_mbox );
serve->mirror = serve->mirror_super->mirror;
server_lock_start_mirror( serve );
{
if ( server_mirror_can_start( serve ) ) {
serve->mirror_super = mirror_super_create(
serve->filename,
connect_to,
connect_from,
max_Bps ,
action_at_finish,
client->mirror_state_mbox );
serve->mirror = serve->mirror_super->mirror;
server_prevent_mirror_start( serve );
} else {
if ( serve->mirror_super ) {
warn( "Tried to start a second mirror run" );
write_socket( "1: mirror already running" );
} else {
warn( "Cannot start mirroring, shutting down" );
write_socket( "1: shutting down" );
}
}
}
server_unlock_start_mirror( serve );
/* Do this outside the lock to minimise the length of time the
* sighandler can block the serve thread
*/
if ( serve->mirror_super ) {
FATAL_IF( 0 != pthread_create(
&serve->mirror_super->thread,
NULL,
@@ -389,6 +405,7 @@ int control_mirror(struct control_client* client, int linesc, char** lines)
debug("Control thread writing response");
control_write_mirror_response( state, client->socket );
}
debug( "Control thread going away." );
return 0;
@@ -438,28 +455,33 @@ int control_break(
struct flexnbd* flexnbd = client->flexnbd;
struct server * serve = flexnbd_server( flexnbd );
if ( server_is_mirroring( serve ) ) {
info( "Signaling to abandon mirror" );
server_abandon_mirror( serve );
debug( "Abandon signaled" );
server_lock_start_mirror( serve );
{
if ( server_is_mirroring( serve ) ) {
if ( server_is_closed( serve ) ) {
info( "Mirror completed while canceling" );
write( client->socket,
"1: mirror completed\n", 20 );
info( "Signaling to abandon mirror" );
server_abandon_mirror( serve );
debug( "Abandon signaled" );
if ( server_is_closed( serve ) ) {
info( "Mirror completed while canceling" );
write( client->socket,
"1: mirror completed\n", 20 );
}
else {
info( "Mirror successfully stopped." );
write( client->socket,
"0: mirror stopped\n", 18 );
result = 1;
}
} else {
warn( "Not mirroring." );
write( client->socket, "1: not mirroring\n", 17 );
}
else {
info( "Mirror successfully stopped." );
write( client->socket,
"0: mirror stopped\n", 18 );
result = 1;
}
} else {
warn( "Not mirroring." );
write( client->socket, "1: not mirroring\n", 17 );
}
server_unlock_start_mirror( serve );
return result;
}