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

mirror: Don't start migrating until the allocation map is built

Browse Source 
There is a fun race that can happen if we begin migrating while the
allocation map is still building. We call bitset_enable_stream()
when the migration begins, which causes the builder to start putting
events into the stream. This is bad all by itself, as it slows the
migration down for no reason, but the stream is a limited-size queue
and there are situations (migration fails and is restarted) where we
can end up with the queue full and nobody able to empty it, freezing
the whole thing.
This commit is contained in:
nick
2013-10-23 15:58:47 +01:00
parent 335261869d
commit 97a923afdf
3 changed files with 49 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
src/serve.h
View File

@@ -76,8 +76,10 @@ struct server {
struct bitset * allocation_map;
/* when starting up, this thread builds the allocation_map */
pthread_t allocation_map_builder_thread;
/* when the thread has finished, it sets this to 1 */
volatile sig_atomic_t allocation_map_built;
volatile sig_atomic_t allocation_map_not_built;
int max_nbd_clients;
struct client_tbl_entry *nbd_client;