[dm-devel] [PATCH] dm: remove dm_mutex (after bkl conversion)
Milan Broz
mbroz at redhat.com
Mon Nov 29 22:53:05 UTC 2010
During the BKL conversion, commit
2a48fc0ab24241755dc93bfd4f01d68efab47f5a
pushed down lock_kernel() into dm_blk_open/close calls
and commit 2a48fc0ab24241755dc93bfd4f01d68efab47f5a
converted it to local mutex.
Patch removes this mutex, DM does not need it, there is
_minor_lock in open call covering create/remove DM device
operation.
In close call there is just atomic reference decrementation
which does not need to be covered by lock.
Signed-off-by: Milan Broz <mbroz at redhat.com>
---
drivers/md/dm.c | 5 -----
1 files changed, 0 insertions(+), 5 deletions(-)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 7cb1352..5ca9fc2 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -32,7 +32,6 @@
#define DM_COOKIE_ENV_VAR_NAME "DM_COOKIE"
#define DM_COOKIE_LENGTH 24
-static DEFINE_MUTEX(dm_mutex);
static const char *_name = DM_NAME;
static unsigned int major = 0;
@@ -328,7 +327,6 @@ static int dm_blk_open(struct block_device *bdev, fmode_t mode)
{
struct mapped_device *md;
- mutex_lock(&dm_mutex);
spin_lock(&_minor_lock);
md = bdev->bd_disk->private_data;
@@ -346,7 +344,6 @@ static int dm_blk_open(struct block_device *bdev, fmode_t mode)
out:
spin_unlock(&_minor_lock);
- mutex_unlock(&dm_mutex);
return md ? 0 : -ENXIO;
}
@@ -355,10 +352,8 @@ static int dm_blk_close(struct gendisk *disk, fmode_t mode)
{
struct mapped_device *md = disk->private_data;
- mutex_lock(&dm_mutex);
atomic_dec(&md->open_count);
dm_put(md);
- mutex_unlock(&dm_mutex);
return 0;
}
--
1.7.2.3
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