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authorJoe Thornber <ejt@redhat.com>2015-11-19 14:50:32 +0100
committerMike Snitzer <snitzer@redhat.com>2016-11-14 21:17:47 +0100
commit2e8ed71102ff8fe3919dd3a2d73ac4da72686efc (patch)
tree517679ff39a4d5c3901976181cf41c76e55be3fe /drivers/md/persistent-data
parentLinux 4.9-rc5 (diff)
downloadlinux-2e8ed71102ff8fe3919dd3a2d73ac4da72686efc.tar.xz
linux-2e8ed71102ff8fe3919dd3a2d73ac4da72686efc.zip
dm block manager: make block locking optional
The block manager's locking is useful for catching cycles that may result from certain btree metadata corruption. But in general it serves as a developer tool to catch bugs in code. Unless you're finding that DM thin provisioning is hanging due to infinite loops within the block manager's access to btree nodes you can safely disable this feature. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> # do/while(0) macro fix Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/persistent-data')
-rw-r--r--drivers/md/persistent-data/dm-block-manager.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index 1e33dd51c21f..a6dde7cab458 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)