[PATCH 4/5 V2] libxfs: Catch non-empty zones on destroy

From: Eric Sandeen <sandeen@sandeen.net>
To: Eric Sandeen <sandeen@redhat.com>, linux-xfs <linux-xfs@vger.kernel.org>
Subject: [PATCH 4/5 V2] libxfs: Catch non-empty zones on destroy
Date: Tue, 6 Mar 2018 17:37:06 -0600	[thread overview]
Message-ID: <7fe7fc2a-8ed6-80d7-0727-0093b19f3164@sandeen.net> (raw)
In-Reply-To: <c2dd15a8-a048-6373-2fad-3ffd28a606e0@sandeen.net>

Create and use a kmem_zone_destroy which warns if we are
releasing a non-empty zone when the LIBXFS_LEAK_CHECK
environment variable is set, wire this into libxfs_destroy(),
and call that when various tools exit.

The LIBXFS_LEAK_CHECK environment variable also causes
the program to exit with failure when a leak is detected,
useful for failing automated tests if leaks are encountered.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

v2 fprintf, stderr

 include/kmem.h |  1 +
 libxfs/init.c  | 36 +++++++++++++++++++++++-------------
 libxfs/kmem.c  | 14 ++++++++++++++
 3 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/include/kmem.h b/include/kmem.h
index 65f0ade..572a4fa 100644
--- a/include/kmem.h
+++ b/include/kmem.h
@@ -33,6 +33,7 @@ typedef struct kmem_zone {
 extern kmem_zone_t *kmem_zone_init(int, char *);
 extern void	*kmem_zone_alloc(kmem_zone_t *, int);
 extern void	*kmem_zone_zalloc(kmem_zone_t *, int);
+extern int	kmem_zone_destroy(kmem_zone_t *);
 
 static inline void
 kmem_zone_free(kmem_zone_t *zone, void *ptr)
diff --git a/libxfs/init.c b/libxfs/init.c
index 3456cb5..a65c86c 100644
--- a/libxfs/init.c
+++ b/libxfs/init.c
@@ -43,7 +43,7 @@ int libxfs_bhash_size;		/* #buckets in bcache */
 
 int	use_xfs_buf_lock;	/* global flag: use xfs_buf_t locks for MT */
 
-static void manage_zones(int);	/* setup global zones */
+static int manage_zones(int);	/* setup/teardown global zones */
 
 /*
  * dev_map - map open devices to fd.
@@ -372,7 +372,7 @@ done:
 /*
  * Initialize/destroy all of the zone allocators we use.
  */
-static void
+static int
 manage_zones(int release)
 {
 	extern kmem_zone_t	*xfs_buf_zone;
@@ -388,16 +388,20 @@ manage_zones(int release)
 	extern void		xfs_dir_startup();
 
 	if (release) {	/* free zone allocation */
-		kmem_free(xfs_buf_zone);
-		kmem_free(xfs_inode_zone);
-		kmem_free(xfs_ifork_zone);
-		kmem_free(xfs_buf_item_zone);
-		kmem_free(xfs_da_state_zone);
-		kmem_free(xfs_btree_cur_zone);
-		kmem_free(xfs_bmap_free_item_zone);
-		kmem_free(xfs_trans_zone);
-		kmem_free(xfs_log_item_desc_zone);
-		return;
+		int	leaked = 0;
+
+		leaked += kmem_zone_destroy(xfs_buf_zone);
+		leaked += kmem_zone_destroy(xfs_ili_zone);
+		leaked += kmem_zone_destroy(xfs_inode_zone);
+		leaked += kmem_zone_destroy(xfs_ifork_zone);
+		leaked += kmem_zone_destroy(xfs_buf_item_zone);
+		leaked += kmem_zone_destroy(xfs_da_state_zone);
+		leaked += kmem_zone_destroy(xfs_btree_cur_zone);
+		leaked += kmem_zone_destroy(xfs_bmap_free_item_zone);
+		leaked += kmem_zone_destroy(xfs_trans_zone);
+		leaked += kmem_zone_destroy(xfs_log_item_desc_zone);
+
+		return leaked;
 	}
 	/* otherwise initialise zone allocation */
 	xfs_buf_zone = kmem_zone_init(sizeof(xfs_buf_t), "xfs_buffer");
@@ -419,6 +423,8 @@ manage_zones(int release)
 	xfs_log_item_desc_zone = kmem_zone_init(
 			sizeof(struct xfs_log_item_desc), "xfs_log_item_desc");
 	xfs_dir_startup();
+
+	return 0;
 }
 
 /*
@@ -887,11 +893,15 @@ libxfs_umount(xfs_mount_t *mp)
 void
 libxfs_destroy(void)
 {
+	int	leaked;
+
 	/* Free everything from the buffer cache before freeing buffer zone */
 	libxfs_bcache_purge();
 	libxfs_bcache_free();
 	cache_destroy(libxfs_bcache);
-	manage_zones(1);
+	leaked = manage_zones(1);
+	if (getenv("LIBXFS_LEAK_CHECK") && leaked)
+		exit(1);
 }
 
 int
diff --git a/libxfs/kmem.c b/libxfs/kmem.c
index c8bcb50..256db94 100644
--- a/libxfs/kmem.c
+++ b/libxfs/kmem.c
@@ -23,6 +23,20 @@ kmem_zone_init(int size, char *name)
 	return ptr;
 }
 
+int
+kmem_zone_destroy(kmem_zone_t *zone)
+{
+	int	leaked = 0;
+
+	if (getenv("LIBXFS_LEAK_CHECK") && zone->allocated) {
+		leaked = 1;
+		fprintf(stderr, "zone %s freed with %d items allocated\n",
+				zone->zone_name, zone->allocated);
+	}
+	free(zone);
+	return leaked;
+}
+
 void *
 kmem_zone_alloc(kmem_zone_t *zone, int flags)
 {


