Add detect_internal_vg_cache_corruption to lvm.conf

Add config option to enable crc checking of VG structures.
Currently it's disabled by default.

For the internal test-suite this check it is enabled.

Note: In the case the internal error is detected, debug build with
compile option DEBUG_ENFORCE_POOL_LOCKING helps to catch the source
of the problem.

5 files changed, 21 insertions, 1 deletions

diff --git a/lib/cache/lvmcache.c b/lib/cache/lvmcache.c
index 189ae1e5..50333dcb 100644
--- a/lib/cache/lvmcache.c
+++ b/lib/cache/lvmcache.c
@@ -689,7 +689,7 @@ struct volume_group *lvmcache_get_vg(const char *vgid, unsigned precommitted)
 	vginfo->vg_use_count = 0;
 	vg->vginfo = vginfo;
 
-	if (!dm_pool_lock(vg->vgmem, 1))
+	if (!dm_pool_lock(vg->vgmem, detect_internal_vg_cache_corruption()))
 		goto_bad;
 
 out:
@@ -720,6 +720,7 @@ int vginfo_holders_dec_and_test_for_zero(struct lvmcache_vginfo *vginfo)
 
 	/* Debug perform crc check only when it's been used more then once */
 	if (!dm_pool_unlock(vginfo->cached_vg->vgmem,
+			    detect_internal_vg_cache_corruption() &&
 			    (vginfo->vg_use_count > 1)))
 		stack;
 
diff --git a/lib/commands/toolcontext.c b/lib/commands/toolcontext.c
index b3d368ad..3cbd29d2 100644
--- a/lib/commands/toolcontext.c
+++ b/lib/commands/toolcontext.c
@@ -373,6 +373,10 @@ static int _process_config(struct cmd_context *cmd)
 	/* LVM stores sizes internally in units of 512-byte sectors. */
 	init_pv_min_size((uint64_t)pv_min_kb * (1024 >> SECTOR_SHIFT));
 
+	init_detect_internal_vg_cache_corruption
+		(find_config_tree_int(cmd, "global/detect_internal_vg_cache_corruption()",
+				      DEFAULT_DETECT_INTERNAL_VG_CACHE_CORRUPTION));
+
 	return 1;
 }
 
diff --git a/lib/config/defaults.h b/lib/config/defaults.h
index cfac4d5b..8b8e09b9 100644
--- a/lib/config/defaults.h
+++ b/lib/config/defaults.h
@@ -103,6 +103,7 @@
 #define DEFAULT_LOGLEVEL 0
 #define DEFAULT_INDENT 1
 #define DEFAULT_ABORT_ON_INTERNAL_ERRORS 0
+#define DEFAULT_DETECT_INTERNAL_VG_CACHE_CORRUPTION 0
 #define DEFAULT_UNITS "h"
 #define DEFAULT_SUFFIX 1
 #define DEFAULT_HOSTTAGS 0
diff --git a/lib/misc/lvm-globals.c b/lib/misc/lvm-globals.c
index b9ece7fe..f7745127 100644
--- a/lib/misc/lvm-globals.c
+++ b/lib/misc/lvm-globals.c
@@ -46,6 +46,8 @@ static int _activation_checks = 0;
 static char _sysfs_dir_path[PATH_MAX] = "";
 static int _dev_disable_after_error_count = DEFAULT_DISABLE_AFTER_ERROR_COUNT;
 static uint64_t _pv_min_size = (DEFAULT_PV_MIN_SIZE_KB * 1024L >> SECTOR_SHIFT);
+static int _detect_internal_vg_cache_corruption =
+	DEFAULT_DETECT_INTERNAL_VG_CACHE_CORRUPTION;
 
 void init_verbose(int level)
 {
@@ -150,6 +152,11 @@ void init_pv_min_size(uint64_t sectors)
 	_pv_min_size = sectors;
 }
 
+void init_detect_internal_vg_cache_corruption(int detect)
+{
+	_detect_internal_vg_cache_corruption = detect;
+}
+
 void set_cmd_name(const char *cmd)
 {
 	strncpy(_cmd_name, cmd, sizeof(_cmd_name));
@@ -284,3 +291,8 @@ uint64_t pv_min_size(void)
 {
 	return _pv_min_size;
 }
+
+int detect_internal_vg_cache_corruption(void)
+{
+	return _detect_internal_vg_cache_corruption;
+}
diff --git a/lib/misc/lvm-globals.h b/lib/misc/lvm-globals.h
index 2cdfdd15..fcba687b 100644
--- a/lib/misc/lvm-globals.h
+++ b/lib/misc/lvm-globals.h
@@ -41,6 +41,7 @@ void init_udev_checking(int checking);
 void init_dev_disable_after_error_count(int value);
 void init_pv_min_size(uint64_t sectors);
 void init_activation_checks(int checks);
+void init_detect_internal_vg_cache_corruption(int detect);
 
 void set_cmd_name(const char *cmd_name);
 void set_sysfs_dir_path(const char *path);
@@ -65,6 +66,7 @@ int udev_checking(void);
 const char *sysfs_dir_path(void);
 uint64_t pv_min_size(void);
 int activation_checks(void);
+int detect_internal_vg_cache_corruption(void);
 
 #define DMEVENTD_MONITOR_IGNORE -1
 int dmeventd_monitor_mode(void);