[PATCH 09/17] mbcache: Add mb_cache_lock

[Matthew Wilcox (Oracle)]

Allow lockdep to track the mbcache hash bit spin locks.

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
---
 fs/mbcache.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/fs/mbcache.c b/fs/mbcache.c
index 97c54d3a2227..4ce03ea348dd 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -47,6 +47,7 @@ static struct kmem_cache *mb_entry_cache;
 static unsigned long mb_cache_shrink(struct mb_cache *cache,
                                     unsigned long nr_to_scan);
 
+static DEFINE_SPLIT_LOCK(mb_cache_lock);
 static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache,
                                                        u32 key)
 {
@@ -97,16 +98,16 @@ int mb_cache_entry_create(struct mb_cache *cache, gfp_t 
mask, u32 key,
        entry->e_reusable = reusable;
        entry->e_referenced = 0;
        head = mb_cache_entry_head(cache, key);
-       hlist_bl_lock(head);
+       hlist_bl_lock(head, &mb_cache_lock);
        hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) {
                if (dup->e_key == key && dup->e_value == value) {
-                       hlist_bl_unlock(head);
+                       hlist_bl_unlock(head, &mb_cache_lock);
                        kmem_cache_free(mb_entry_cache, entry);
                        return -EBUSY;
                }
        }
        hlist_bl_add_head(&entry->e_hash_list, head);
-       hlist_bl_unlock(head);
+       hlist_bl_unlock(head, &mb_cache_lock);
 
        spin_lock(&cache->c_list_lock);
        list_add_tail(&entry->e_list, &cache->c_list);
@@ -134,7 +135,7 @@ static struct mb_cache_entry *__entry_find(struct mb_cache 
*cache,
        struct hlist_bl_head *head;
 
        head = mb_cache_entry_head(cache, key);
-       hlist_bl_lock(head);
+       hlist_bl_lock(head, &mb_cache_lock);
        if (entry && !hlist_bl_unhashed(&entry->e_hash_list))
                node = entry->e_hash_list.next;
        else
@@ -150,7 +151,7 @@ static struct mb_cache_entry *__entry_find(struct mb_cache 
*cache,
        }
        entry = NULL;
 out:
-       hlist_bl_unlock(head);
+       hlist_bl_unlock(head, &mb_cache_lock);
        if (old_entry)
                mb_cache_entry_put(cache, old_entry);
 
@@ -203,7 +204,7 @@ struct mb_cache_entry *mb_cache_entry_get(struct mb_cache 
*cache, u32 key,
        struct mb_cache_entry *entry;
 
        head = mb_cache_entry_head(cache, key);
-       hlist_bl_lock(head);
+       hlist_bl_lock(head, &mb_cache_lock);
        hlist_bl_for_each_entry(entry, node, head, e_hash_list) {
                if (entry->e_key == key && entry->e_value == value) {
                        atomic_inc(&entry->e_refcnt);
@@ -212,7 +213,7 @@ struct mb_cache_entry *mb_cache_entry_get(struct mb_cache 
*cache, u32 key,
        }
        entry = NULL;
 out:
-       hlist_bl_unlock(head);
+       hlist_bl_unlock(head, &mb_cache_lock);
        return entry;
 }
 EXPORT_SYMBOL(mb_cache_entry_get);
@@ -231,12 +232,12 @@ void mb_cache_entry_delete(struct mb_cache *cache, u32 
key, u64 value)
        struct mb_cache_entry *entry;
 
        head = mb_cache_entry_head(cache, key);
-       hlist_bl_lock(head);
+       hlist_bl_lock(head, &mb_cache_lock);
        hlist_bl_for_each_entry(entry, node, head, e_hash_list) {
                if (entry->e_key == key && entry->e_value == value) {
                        /* We keep hash list reference to keep entry alive */
                        hlist_bl_del_init(&entry->e_hash_list);
-                       hlist_bl_unlock(head);
+                       hlist_bl_unlock(head, &mb_cache_lock);
                        spin_lock(&cache->c_list_lock);
                        if (!list_empty(&entry->e_list)) {
                                list_del_init(&entry->e_list);
@@ -250,7 +251,7 @@ void mb_cache_entry_delete(struct mb_cache *cache, u32 key, 
u64 value)
                        return;
                }
        }
-       hlist_bl_unlock(head);
+       hlist_bl_unlock(head, &mb_cache_lock);
 }
 EXPORT_SYMBOL(mb_cache_entry_delete);
 
@@ -301,12 +302,12 @@ static unsigned long mb_cache_shrink(struct mb_cache 
*cache,
                 */
                spin_unlock(&cache->c_list_lock);
                head = mb_cache_entry_head(cache, entry->e_key);
-               hlist_bl_lock(head);
+               hlist_bl_lock(head, &mb_cache_lock);
                if (!hlist_bl_unhashed(&entry->e_hash_list)) {
                        hlist_bl_del_init(&entry->e_hash_list);
                        atomic_dec(&entry->e_refcnt);
                }
-               hlist_bl_unlock(head);
+               hlist_bl_unlock(head, &mb_cache_lock);
                if (mb_cache_entry_put(cache, entry))
                        shrunk++;
                cond_resched();
-- 
2.30.2