From 2d4f78588bd6a3ed145dfde0df5f6c016e8cde75 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Tue, 19 Jun 2018 23:33:28 -0700
Subject: [PATCH] hammer2 - Check duplicate H2 partitions during hammer2
 cleanup

* hammer2 cleanup operates on the partition the mount resides on,
  so if multiple hammer2 snapshots from the same partition are mounted
  we do not need to run it for each mount.
---
 sbin/hammer2/cmd_cleanup.c | 73 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 71 insertions(+), 2 deletions(-)

diff --git a/sbin/hammer2/cmd_cleanup.c b/sbin/hammer2/cmd_cleanup.c
index 35f0d18106..c16a647e03 100644
--- a/sbin/hammer2/cmd_cleanup.c
+++ b/sbin/hammer2/cmd_cleanup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 The DragonFly Project.  All rights reserved.
+ * Copyright (c) 2017-2018 The DragonFly Project.  All rights reserved.
  *
  * This code is derived from software contributed to The DragonFly Project
  * by Matthew Dillon <dillon@dragonflybsd.org>
@@ -32,6 +32,9 @@
 #include "hammer2.h"
 
 static int docleanup(const char *path);
+static int sameh2prefix(const char *from);
+static void saveh2prefix(const char *from);
+static void freeh2prefixes(void);
 
 int
 cmd_cleanup(const char *sel_path)
@@ -39,6 +42,7 @@ cmd_cleanup(const char *sel_path)
 	struct statfs *fsary;
 	char *fstype;
 	char *path;
+	char *from;
 	int i;
 	int n;
 	int r;
@@ -56,13 +60,22 @@ cmd_cleanup(const char *sel_path)
 	for (i = 0; i < n; ++i) {
 		fstype = fsary[i].f_fstypename;
 		path = fsary[i].f_mntonname;
+		from = fsary[i].f_mntfromname;
 
-		if (strcmp(fstype, "hammer2") == 0) {
+		if (strcmp(fstype, "hammer2") != 0)
+			continue;
+		if (sameh2prefix(from)) {
+			printf("hammer2 cleanup \"%s\" (same partition)\n",
+				path);
+		} else {
 			r = docleanup(path);
 			if (r)
 				rc = r;
+			saveh2prefix(from);
 		}
 	}
+	freeh2prefixes();
+
 	return rc;
 }
 
@@ -77,3 +90,59 @@ docleanup(const char *path)
 
 	return rc;
 }
+
+char **h2prefixes;
+int h2count;
+int h2limit;
+
+static
+int
+sameh2prefix(const char *from)
+{
+	char *ptr;
+	int rc = 0;
+	int i;
+
+	ptr = strdup(from);
+	if (strchr(ptr, '@'))
+		*strchr(ptr, '@') = 0;
+	for (i = 0; i < h2count; ++i) {
+		if (strcmp(h2prefixes[i], ptr) == 0) {
+			rc = 1;
+			break;
+		}
+	}
+	free(ptr);
+
+	return rc;
+}
+
+static
+void
+saveh2prefix(const char *from)
+{
+	char *ptr;
+
+	if (h2count >= h2limit) {
+		h2limit = (h2limit + 8) << 1;
+		h2prefixes = realloc(h2prefixes, sizeof(char *) * h2limit);
+	}
+	ptr = strdup(from);
+	if (strchr(ptr, '@'))
+		*strchr(ptr, '@') = 0;
+	h2prefixes[h2count++] = ptr;
+}
+
+static
+void
+freeh2prefixes(void)
+{
+	int i;
+
+	for (i = 0; i < h2count; ++i)
+		free(h2prefixes[i]);
+	free(h2prefixes);
+	h2prefixes = NULL;
+	h2count = 0;
+	h2limit = 0;
+}
-- 
2.41.0