Add orphan-log-trees test and reclaim_skip_finalize trigger

Add a reclaim_skip_finalize trigger that prevents reclaim from
setting FINALIZED on log_trees entries.  The test arms this trigger,
force-unmounts a client to create an orphan, and verifies the log
merge succeeds without timeout and the orphan reclaim message
appears in dmesg.

Signed-off-by: Auke Kok <auke.kok@versity.com>

kmod/src/server.c

@@ -2023,7 +2023,7 @@ static int reclaim_open_log_tree(struct super_block *sb, u64 rid)
 	mutex_unlock(&server->alloc_mutex);
 
 	/* only finalize, allowing merging, once the allocators are fully freed */
-	if (ret == 0) {
+	if (ret == 0 && !scoutfs_trigger(sb, RECLAIM_SKIP_FINALIZE)) {
 		/* the transaction is no longer open */
 		lt.commit_trans_seq = lt.get_trans_seq;
 

kmod/src/triggers.c

@@ -45,6 +45,7 @@ static char *names[] = {
 	[SCOUTFS_TRIGGER_SRCH_FORCE_LOG_ROTATE] = "srch_force_log_rotate",
 	[SCOUTFS_TRIGGER_SRCH_MERGE_STOP_SAFE] = "srch_merge_stop_safe",
 	[SCOUTFS_TRIGGER_STATFS_LOCK_PURGE] = "statfs_lock_purge",
+	[SCOUTFS_TRIGGER_RECLAIM_SKIP_FINALIZE] = "reclaim_skip_finalize",
 };
 
 bool scoutfs_trigger_test_and_clear(struct super_block *sb, unsigned int t)

kmod/src/triggers.h

@@ -8,6 +8,7 @@ enum scoutfs_trigger {
 	SCOUTFS_TRIGGER_SRCH_FORCE_LOG_ROTATE,
 	SCOUTFS_TRIGGER_SRCH_MERGE_STOP_SAFE,
 	SCOUTFS_TRIGGER_STATFS_LOCK_PURGE,
+	SCOUTFS_TRIGGER_RECLAIM_SKIP_FINALIZE,
 	SCOUTFS_TRIGGER_NR,
 };