staging: zcache: support multiple clients, prep for KVM and RAMster

[pandora-kernel.git] / drivers / staging / zcache / tmem.c

diff --git a/drivers/staging/zcache/tmem.c b/drivers/staging/zcache/tmem.c
index e954d40..975e34b 100644 (file)
--- a/drivers/staging/zcache/tmem.c
+++ b/drivers/staging/zcache/tmem.c
@@ -142,6 +142,7 @@ static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb,
        obj->oid = *oidp;
        obj->objnode_count = 0;
        obj->pampd_count = 0;
+       (*tmem_pamops.new_obj)(obj);
        SET_SENTINEL(obj, OBJ);
        while (*new) {
                BUG_ON(RB_EMPTY_NODE(*new));
@@ -274,7 +275,7 @@ static void tmem_objnode_free(struct tmem_objnode *objnode)
 /*
  * lookup index in object and return associated pampd (or NULL if not found)
  */
-static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
+static void **__tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
 {
        unsigned int height, shift;
        struct tmem_objnode **slot = NULL;
@@ -303,9 +304,33 @@ static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
                height--;
        }
 out:
+       return slot != NULL ? (void **)slot : NULL;
+}
+
+static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
+{
+       struct tmem_objnode **slot;
+
+       slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index);
        return slot != NULL ? *slot : NULL;
 }
 
+static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index,
+                                       void *new_pampd)
+{
+       struct tmem_objnode **slot;
+       void *ret = NULL;
+
+       slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index);
+       if ((slot != NULL) && (*slot != NULL)) {
+               void *old_pampd = *(void **)slot;
+               *(void **)slot = new_pampd;
+               (*tmem_pamops.free)(old_pampd, obj->pool, NULL, 0);
+               ret = new_pampd;
+       }
+       return ret;
+}
+
 static int tmem_pampd_add_to_obj(struct tmem_obj *obj, uint32_t index,
                                        void *pampd)
 {
@@ -456,7 +481,7 @@ static void tmem_objnode_node_destroy(struct tmem_obj *obj,
                        if (ht == 1) {
                                obj->pampd_count--;
                                (*tmem_pamops.free)(objnode->slots[i],
-                                                               obj->pool);
+                                               obj->pool, NULL, 0);
                                objnode->slots[i] = NULL;
                                continue;
                        }
@@ -473,7 +498,7 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj)
                return;
        if (obj->objnode_tree_height == 0) {
                obj->pampd_count--;
-               (*tmem_pamops.free)(obj->objnode_tree_root, obj->pool);
+               (*tmem_pamops.free)(obj->objnode_tree_root, obj->pool, NULL, 0);
        } else {
                tmem_objnode_node_destroy(obj, obj->objnode_tree_root,
                                        obj->objnode_tree_height);
@@ -481,6 +506,7 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj)
                obj->objnode_tree_height = 0;
        }
        obj->objnode_tree_root = NULL;
+       (*tmem_pamops.free_obj)(obj->pool, obj);
 }
 
 /*
@@ -503,15 +529,13 @@ static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj)
  * always flushes for simplicity.
  */
 int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
-               struct page *page)
+               char *data, size_t size, bool raw, bool ephemeral)
 {
        struct tmem_obj *obj = NULL, *objfound = NULL, *objnew = NULL;
        void *pampd = NULL, *pampd_del = NULL;
        int ret = -ENOMEM;
-       bool ephemeral;
        struct tmem_hashbucket *hb;
 
-       ephemeral = is_ephemeral(pool);
        hb = &pool->hashbucket[tmem_oid_hash(oidp)];
        spin_lock(&hb->lock);
        obj = objfound = tmem_obj_find(hb, oidp);
@@ -521,7 +545,7 @@ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
                        /* if found, is a dup put, flush the old one */
                        pampd_del = tmem_pampd_delete_from_obj(obj, index);
                        BUG_ON(pampd_del != pampd);
-                       (*tmem_pamops.free)(pampd, pool);
+                       (*tmem_pamops.free)(pampd, pool, oidp, index);
                        if (obj->pampd_count == 0) {
                                objnew = obj;
                                objfound = NULL;
@@ -538,7 +562,8 @@ int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
        }
        BUG_ON(obj == NULL);
        BUG_ON(((objnew != obj) && (objfound != obj)) || (objnew == objfound));
-       pampd = (*tmem_pamops.create)(obj->pool, &obj->oid, index, page);
+       pampd = (*tmem_pamops.create)(data, size, raw, ephemeral,
+                                       obj->pool, &obj->oid, index);
        if (unlikely(pampd == NULL))
                goto free;
        ret = tmem_pampd_add_to_obj(obj, index, pampd);
@@ -551,7 +576,7 @@ delete_and_free:
        (void)tmem_pampd_delete_from_obj(obj, index);
 free:
        if (pampd)
-               (*tmem_pamops.free)(pampd, pool);
+               (*tmem_pamops.free)(pampd, pool, NULL, 0);
        if (objnew) {
                tmem_obj_free(objnew, hb);
                (*tmem_hostops.obj_free)(objnew, pool);
@@ -573,41 +598,52 @@ out:
  * "put" done with the same handle).
 
  */
-int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp,
-                               uint32_t index, struct page *page)
+int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
+               char *data, size_t *size, bool raw, int get_and_free)
 {
        struct tmem_obj *obj;
        void *pampd;
        bool ephemeral = is_ephemeral(pool);
        uint32_t ret = -1;
        struct tmem_hashbucket *hb;
+       bool free = (get_and_free == 1) || ((get_and_free == 0) && ephemeral);
+       bool lock_held = false;
 
        hb = &pool->hashbucket[tmem_oid_hash(oidp)];
        spin_lock(&hb->lock);
+       lock_held = true;
        obj = tmem_obj_find(hb, oidp);
        if (obj == NULL)
                goto out;
-       ephemeral = is_ephemeral(pool);
-       if (ephemeral)
+       if (free)
                pampd = tmem_pampd_delete_from_obj(obj, index);
        else
                pampd = tmem_pampd_lookup_in_obj(obj, index);
        if (pampd == NULL)
                goto out;
-       ret = (*tmem_pamops.get_data)(page, pampd, pool);
-       if (ret < 0)
-               goto out;
-       if (ephemeral) {
-               (*tmem_pamops.free)(pampd, pool);
+       if (free) {
                if (obj->pampd_count == 0) {
                        tmem_obj_free(obj, hb);
                        (*tmem_hostops.obj_free)(obj, pool);
                        obj = NULL;
                }
        }
+       if (tmem_pamops.is_remote(pampd)) {
+               lock_held = false;
+               spin_unlock(&hb->lock);
+       }
+       if (free)
+               ret = (*tmem_pamops.get_data_and_free)(
+                               data, size, raw, pampd, pool, oidp, index);
+       else
+               ret = (*tmem_pamops.get_data)(
+                               data, size, raw, pampd, pool, oidp, index);
+       if (ret < 0)
+               goto out;
        ret = 0;
 out:
-       spin_unlock(&hb->lock);
+       if (lock_held)
+               spin_unlock(&hb->lock);
        return ret;
 }
 
@@ -632,7 +668,7 @@ int tmem_flush_page(struct tmem_pool *pool,
        pampd = tmem_pampd_delete_from_obj(obj, index);
        if (pampd == NULL)
                goto out;
-       (*tmem_pamops.free)(pampd, pool);
+       (*tmem_pamops.free)(pampd, pool, oidp, index);
        if (obj->pampd_count == 0) {
                tmem_obj_free(obj, hb);
                (*tmem_hostops.obj_free)(obj, pool);
@@ -644,6 +680,30 @@ out:
        return ret;
 }
 
+/*
+ * If a page in tmem matches the handle, replace the page so that any
+ * subsequent "get" gets the new page.  Returns 0 if
+ * there was a page to replace, else returns -1.
+ */
+int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp,
+                       uint32_t index, void *new_pampd)
+{
+       struct tmem_obj *obj;
+       int ret = -1;
+       struct tmem_hashbucket *hb;
+
+       hb = &pool->hashbucket[tmem_oid_hash(oidp)];
+       spin_lock(&hb->lock);
+       obj = tmem_obj_find(hb, oidp);
+       if (obj == NULL)
+               goto out;
+       new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd);
+       ret = (*tmem_pamops.replace_in_obj)(new_pampd, obj);
+out:
+       spin_unlock(&hb->lock);
+       return ret;
+}
+
 /*
  * "Flush" all pages in tmem matching this oid.
  */