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author | Keir Fraser <keir.fraser@citrix.com> | 2008-05-06 13:34:52 +0100 |
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committer | Keir Fraser <keir.fraser@citrix.com> | 2008-05-06 13:34:52 +0100 |
commit | cc489fb3c4f2d523cba4b8b13d2bf83564de8254 (patch) | |
tree | c1c5303e97b6a35ce3693489d27c1dd378593e4e /extras/mini-os/blkfront.c | |
parent | ea1c7a7225787dcda405a1a75a1e982624f1ef1a (diff) | |
download | xen-cc489fb3c4f2d523cba4b8b13d2bf83564de8254.tar.gz xen-cc489fb3c4f2d523cba4b8b13d2bf83564de8254.tar.bz2 xen-cc489fb3c4f2d523cba4b8b13d2bf83564de8254.zip |
minios: fix thread safety of xenbus watches by requiring callers to
provide their own queue of events, because else we can not dispatch to
watchers running in parallel.
Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
Diffstat (limited to 'extras/mini-os/blkfront.c')
-rw-r--r-- | extras/mini-os/blkfront.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/extras/mini-os/blkfront.c b/extras/mini-os/blkfront.c index 8588518607..84914346f9 100644 --- a/extras/mini-os/blkfront.c +++ b/extras/mini-os/blkfront.c @@ -50,6 +50,8 @@ struct blkfront_dev { char *backend; struct blkfront_info info; + xenbus_event_queue events; + #ifdef HAVE_LIBC int fd; #endif @@ -101,6 +103,8 @@ struct blkfront_dev *init_blkfront(char *nodename, struct blkfront_info *info) dev->ring_ref = gnttab_grant_access(dev->dom,virt_to_mfn(s),0); + dev->events = NULL; + // FIXME: proper frees on failures again: err = xenbus_transaction_start(&xbt); @@ -166,11 +170,9 @@ done: snprintf(path, sizeof(path), "%s/state", dev->backend); - xenbus_watch_path(XBT_NIL, path); + xenbus_watch_path_token(XBT_NIL, path, path, &dev->events); - xenbus_wait_for_value(path,"4"); - - xenbus_unwatch_path(XBT_NIL, path); + xenbus_wait_for_value(path, "4", &dev->events); snprintf(path, sizeof(path), "%s/info", dev->backend); dev->info.info = xenbus_read_integer(path); @@ -211,10 +213,12 @@ void shutdown_blkfront(struct blkfront_dev *dev) snprintf(path, sizeof(path), "%s/state", dev->backend); err = xenbus_printf(XBT_NIL, nodename, "state", "%u", 5); /* closing */ - xenbus_wait_for_value(path,"5"); + xenbus_wait_for_value(path, "5", &dev->events); err = xenbus_printf(XBT_NIL, nodename, "state", "%u", 6); - xenbus_wait_for_value(path,"6"); + xenbus_wait_for_value(path, "6", &dev->events); + + xenbus_unwatch_path(XBT_NIL, path); unbind_evtchn(dev->evtchn); |