[DLM] fix stopping unstarted recovery
Red Hat BZ 211914
When many nodes are joining a lockspace simultaneously, the dlm gets a
quick sequence of stop/start events, a pair for adding each node.
dlm_controld in user space sends dlm_recoverd in the kernel each stop and
start event. dlm_controld will sometimes send the stop before
dlm_recoverd has had a chance to take up the previously queued start. The
stop aborts the processing of the previous start by setting the
RECOVERY_STOP flag. dlm_recoverd is erroneously clearing this flag and
ignoring the stop/abort if it happens to take up the start after the stop
meant to abort it. The fix is to check the sequence number that's
incremented for each stop/start before clearing the flag.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c
index 4a1d602..6e4ee94 100644
--- a/fs/dlm/recoverd.c
+++ b/fs/dlm/recoverd.c
@@ -219,6 +219,10 @@
return error;
}
+/* The dlm_ls_start() that created the rv we take here may already have been
+ stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
+ flag set. */
+
static void do_ls_recovery(struct dlm_ls *ls)
{
struct dlm_recover *rv = NULL;
@@ -226,7 +230,8 @@
spin_lock(&ls->ls_recover_lock);
rv = ls->ls_recover_args;
ls->ls_recover_args = NULL;
- clear_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
+ if (rv && ls->ls_recover_seq == rv->seq)
+ clear_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
spin_unlock(&ls->ls_recover_lock);
if (rv) {