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path: root/fs/xfs/xfs_mru_cache.c
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Diffstat (limited to 'fs/xfs/xfs_mru_cache.c')
-rw-r--r--fs/xfs/xfs_mru_cache.c54
1 files changed, 32 insertions, 22 deletions
diff --git a/fs/xfs/xfs_mru_cache.c b/fs/xfs/xfs_mru_cache.c
index e0b358c1c533..a0b2c0a2589a 100644
--- a/fs/xfs/xfs_mru_cache.c
+++ b/fs/xfs/xfs_mru_cache.c
@@ -225,10 +225,14 @@ _xfs_mru_cache_list_insert(
* list need to be deleted. For each element this involves removing it from the
* data store, removing it from the reap list, calling the client's free
* function and deleting the element from the element zone.
+ *
+ * We get called holding the mru->lock, which we drop and then reacquire.
+ * Sparse need special help with this to tell it we know what we are doing.
*/
STATIC void
_xfs_mru_cache_clear_reap_list(
- xfs_mru_cache_t *mru)
+ xfs_mru_cache_t *mru) __releases(mru->lock) __acquires(mru->lock)
+
{
xfs_mru_cache_elem_t *elem, *next;
struct list_head tmp;
@@ -245,7 +249,7 @@ _xfs_mru_cache_clear_reap_list(
*/
list_move(&elem->list_node, &tmp);
}
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
list_for_each_entry_safe(elem, next, &tmp, list_node) {
@@ -259,7 +263,7 @@ _xfs_mru_cache_clear_reap_list(
kmem_zone_free(xfs_mru_elem_zone, elem);
}
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
}
/*
@@ -280,7 +284,7 @@ _xfs_mru_cache_reap(
if (!mru || !mru->lists)
return;
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
next = _xfs_mru_cache_migrate(mru, jiffies);
_xfs_mru_cache_clear_reap_list(mru);
@@ -294,7 +298,7 @@ _xfs_mru_cache_reap(
queue_delayed_work(xfs_mru_reap_wq, &mru->work, next);
}
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
}
int
@@ -368,7 +372,7 @@ xfs_mru_cache_create(
*/
INIT_RADIX_TREE(&mru->store, GFP_ATOMIC);
INIT_LIST_HEAD(&mru->reap_list);
- spinlock_init(&mru->lock, "xfs_mru_cache");
+ spin_lock_init(&mru->lock);
INIT_DELAYED_WORK(&mru->work, _xfs_mru_cache_reap);
mru->grp_time = grp_time;
@@ -398,17 +402,17 @@ xfs_mru_cache_flush(
if (!mru || !mru->lists)
return;
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
if (mru->queued) {
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
cancel_rearming_delayed_workqueue(xfs_mru_reap_wq, &mru->work);
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
}
_xfs_mru_cache_migrate(mru, jiffies + mru->grp_count * mru->grp_time);
_xfs_mru_cache_clear_reap_list(mru);
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
}
void
@@ -454,13 +458,13 @@ xfs_mru_cache_insert(
elem->key = key;
elem->value = value;
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
radix_tree_insert(&mru->store, key, elem);
radix_tree_preload_end();
_xfs_mru_cache_list_insert(mru, elem);
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
return 0;
}
@@ -483,14 +487,14 @@ xfs_mru_cache_remove(
if (!mru || !mru->lists)
return NULL;
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
elem = radix_tree_delete(&mru->store, key);
if (elem) {
value = elem->value;
list_del(&elem->list_node);
}
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
if (elem)
kmem_zone_free(xfs_mru_elem_zone, elem);
@@ -528,6 +532,10 @@ xfs_mru_cache_delete(
*
* If the element isn't found, this function returns NULL and the spinlock is
* released. xfs_mru_cache_done() should NOT be called when this occurs.
+ *
+ * Because sparse isn't smart enough to know about conditional lock return
+ * status, we need to help it get it right by annotating the path that does
+ * not release the lock.
*/
void *
xfs_mru_cache_lookup(
@@ -540,14 +548,14 @@ xfs_mru_cache_lookup(
if (!mru || !mru->lists)
return NULL;
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
elem = radix_tree_lookup(&mru->store, key);
if (elem) {
list_del(&elem->list_node);
_xfs_mru_cache_list_insert(mru, elem);
- }
- else
- mutex_spinunlock(&mru->lock, 0);
+ __release(mru_lock); /* help sparse not be stupid */
+ } else
+ spin_unlock(&mru->lock);
return elem ? elem->value : NULL;
}
@@ -571,10 +579,12 @@ xfs_mru_cache_peek(
if (!mru || !mru->lists)
return NULL;
- mutex_spinlock(&mru->lock);
+ spin_lock(&mru->lock);
elem = radix_tree_lookup(&mru->store, key);
if (!elem)
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
+ else
+ __release(mru_lock); /* help sparse not be stupid */
return elem ? elem->value : NULL;
}
@@ -586,7 +596,7 @@ xfs_mru_cache_peek(
*/
void
xfs_mru_cache_done(
- xfs_mru_cache_t *mru)
+ xfs_mru_cache_t *mru) __releases(mru->lock)
{
- mutex_spinunlock(&mru->lock, 0);
+ spin_unlock(&mru->lock);
}