dm: remove dm_mutex after bkl conversion

This patch replaces dm_mutex with _minor_lock in dm_blk_close()
and then removes it.

During the BKL conversion, commit 6e9624b8ca
(block: push down BKL into .open and .release) pushed lock_kernel()
down into dm_blk_open/close calls.
Commit 2a48fc0ab2
(block: autoconvert trivial BKL users to private mutex) converted it to a
local mutex, but _minor_lock is sufficient.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Milan Broz 2011-01-13 19:59:48 +00:00 committed by Alasdair G Kergon
parent 5fc2ffeabb
commit 4a1aeb9829

View file

@ -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 +352,12 @@ static int dm_blk_close(struct gendisk *disk, fmode_t mode)
{
struct mapped_device *md = disk->private_data;
mutex_lock(&dm_mutex);
spin_lock(&_minor_lock);
atomic_dec(&md->open_count);
dm_put(md);
mutex_unlock(&dm_mutex);
spin_unlock(&_minor_lock);
return 0;
}