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-rw-r--r--drivers/md/Kconfig10
-rw-r--r--drivers/md/persistent-data/dm-block-manager.c19
2 files changed, 27 insertions, 2 deletions
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 02a5345..b7767da 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -240,9 +240,17 @@ config DM_BUFIO
as a cache, holding recently-read blocks in memory and performing
delayed writes.
+config DM_DEBUG_BLOCK_MANAGER_LOCKING
+ bool "Block manager locking"
+ depends on DM_BUFIO
+ ---help---
+ Block manager locking can catch various metadata corruption issues.
+
+ If unsure, say N.
+
config DM_DEBUG_BLOCK_STACK_TRACING
bool "Keep stack trace of persistent data block lock holders"
- depends on STACKTRACE_SUPPORT && DM_BUFIO
+ depends on STACKTRACE_SUPPORT && DM_DEBUG_BLOCK_MANAGER_LOCKING
select STACKTRACE
---help---
Enable this for messages that may help debug problems with the
diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index 1e33dd5..a6dde7c 100644
--- a/drivers/md/persistent-data/dm-block-manager.c
+++ b/drivers/md/persistent-data/dm-block-manager.c
@@ -18,6 +18,8 @@
/*----------------------------------------------------------------*/
+#ifdef CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING
+
/*
* This is a read/write semaphore with a couple of differences.
*
@@ -302,6 +304,18 @@ static void report_recursive_bug(dm_block_t b, int r)
(unsigned long long) b);
}
+#else /* !CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING */
+
+#define bl_init(x) do { } while (0)
+#define bl_down_read(x) 0
+#define bl_down_read_nonblock(x) 0
+#define bl_up_read(x) do { } while (0)
+#define bl_down_write(x) 0
+#define bl_up_write(x) do { } while (0)
+#define report_recursive_bug(x, y) do { } while (0)
+
+#endif /* CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING */
+
/*----------------------------------------------------------------*/
/*
@@ -330,8 +344,11 @@ EXPORT_SYMBOL_GPL(dm_block_data);
struct buffer_aux {
struct dm_block_validator *validator;
- struct block_lock lock;
int write_locked;
+
+#ifdef CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING
+ struct block_lock lock;
+#endif
};
static void dm_block_manager_alloc_callback(struct dm_buffer *buf)
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