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| author | Joe Thornber <ejt@redhat.com> | 2015-11-19 13:50:32 +0000 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-11-14 15:17:47 -0500 |
| commit | 2e8ed71102ff8fe3919dd3a2d73ac4da72686efc (patch) | |
| tree | 517679ff39a4d5c3901976181cf41c76e55be3fe | |
| parent | a25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6 (diff) | |
| download | linux-2e8ed71102ff8fe3919dd3a2d73ac4da72686efc.tar.gz linux-2e8ed71102ff8fe3919dd3a2d73ac4da72686efc.tar.bz2 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>
| -rw-r--r-- | drivers/md/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/md/persistent-data/dm-block-manager.c | 19 |
2 files changed, 27 insertions, 2 deletions
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 02a5345a44a6..b7767da50c26 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 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) |