diff options
| -rw-r--r-- | drivers/md/dm.c | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 6e577e74932..6e65d85d082 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -26,6 +26,7 @@ static const char *_name = DM_NAME; static unsigned int major = 0; static unsigned int _major = 0; +static DEFINE_SPINLOCK(_minor_lock); /* * One of these is allocated per bio. */ @@ -746,14 +747,13 @@ static int dm_any_congested(void *congested_data, int bdi_bits) /*----------------------------------------------------------------- * An IDR is used to keep track of allocated minor numbers. *---------------------------------------------------------------*/ -static DEFINE_MUTEX(_minor_lock); static DEFINE_IDR(_minor_idr); static void free_minor(unsigned int minor) { - mutex_lock(&_minor_lock); + spin_lock(&_minor_lock); idr_remove(&_minor_idr, minor); - mutex_unlock(&_minor_lock); + spin_unlock(&_minor_lock); } /* @@ -770,7 +770,7 @@ static int specific_minor(struct mapped_device *md, unsigned int minor) if (!r) return -ENOMEM; - mutex_lock(&_minor_lock); + spin_lock(&_minor_lock); if (idr_find(&_minor_idr, minor)) { r = -EBUSY; @@ -788,7 +788,7 @@ static int specific_minor(struct mapped_device *md, unsigned int minor) } out: - mutex_unlock(&_minor_lock); + spin_unlock(&_minor_lock); return r; } @@ -801,7 +801,7 @@ static int next_free_minor(struct mapped_device *md, unsigned int *minor) if (!r) return -ENOMEM; - mutex_lock(&_minor_lock); + spin_lock(&_minor_lock); r = idr_get_new(&_minor_idr, MINOR_ALLOCED, &m); if (r) { @@ -817,7 +817,7 @@ static int next_free_minor(struct mapped_device *md, unsigned int *minor) *minor = m; out: - mutex_unlock(&_minor_lock); + spin_unlock(&_minor_lock); return r; } @@ -887,9 +887,9 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent) init_waitqueue_head(&md->eventq); /* Populate the mapping, nobody knows we exist yet */ - mutex_lock(&_minor_lock); + spin_lock(&_minor_lock); old_md = idr_replace(&_minor_idr, md, minor); - mutex_unlock(&_minor_lock); + spin_unlock(&_minor_lock); BUG_ON(old_md != MINOR_ALLOCED); @@ -1020,13 +1020,13 @@ static struct mapped_device *dm_find_md(dev_t dev) if (MAJOR(dev) != _major || minor >= (1 << MINORBITS)) return NULL; - mutex_lock(&_minor_lock); + spin_lock(&_minor_lock); md = idr_find(&_minor_idr, minor); if (md && (md == MINOR_ALLOCED || (dm_disk(md)->first_minor != minor))) md = NULL; - mutex_unlock(&_minor_lock); + spin_unlock(&_minor_lock); return md; } @@ -1060,11 +1060,10 @@ void dm_put(struct mapped_device *md) { struct dm_table *map; - if (atomic_dec_and_test(&md->holders)) { + if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { map = dm_get_table(md); - mutex_lock(&_minor_lock); idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor); - mutex_unlock(&_minor_lock); + spin_unlock(&_minor_lock); if (!dm_suspended(md)) { dm_table_presuspend_targets(map); dm_table_postsuspend_targets(map); |