diff options
| -rw-r--r-- | drivers/staging/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/staging/Makefile | 1 | ||||
| -rw-r--r-- | drivers/staging/zcache/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/staging/zcache/Makefile | 3 | ||||
| -rw-r--r-- | drivers/staging/zcache/tmem.c | 773 | ||||
| -rw-r--r-- | drivers/staging/zcache/tmem.h | 206 | ||||
| -rw-r--r-- | drivers/staging/zcache/zcache-main.c | 2077 |
7 files changed, 0 insertions, 3073 deletions
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index 329bdb42109..db8a5121daf 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -74,8 +74,6 @@ source "drivers/staging/iio/Kconfig" source "drivers/staging/zram/Kconfig" -source "drivers/staging/zcache/Kconfig" - source "drivers/staging/zsmalloc/Kconfig" source "drivers/staging/wlags49_h2/Kconfig" diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index c7ec486680f..a9d54798367 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -31,7 +31,6 @@ obj-$(CONFIG_VME_BUS) += vme/ obj-$(CONFIG_DX_SEP) += sep/ obj-$(CONFIG_IIO) += iio/ obj-$(CONFIG_ZRAM) += zram/ -obj-$(CONFIG_ZCACHE) += zcache/ obj-$(CONFIG_ZSMALLOC) += zsmalloc/ obj-$(CONFIG_WLAGS49_H2) += wlags49_h2/ obj-$(CONFIG_WLAGS49_H25) += wlags49_h25/ diff --git a/drivers/staging/zcache/Kconfig b/drivers/staging/zcache/Kconfig deleted file mode 100644 index 4881839be62..00000000000 --- a/drivers/staging/zcache/Kconfig +++ /dev/null @@ -1,11 +0,0 @@ -config ZCACHE - bool "Dynamic compression of swap pages and clean pagecache pages" - depends on (CLEANCACHE || FRONTSWAP) && CRYPTO=y && ZSMALLOC=y - select CRYPTO_LZO - default n - help - Zcache doubles RAM efficiency while providing a significant - performance boosts on many workloads. Zcache uses - compression and an in-kernel implementation of transcendent - memory to store clean page cache pages and swap in RAM, - providing a noticeable reduction in disk I/O. diff --git a/drivers/staging/zcache/Makefile b/drivers/staging/zcache/Makefile deleted file mode 100644 index 60daa272c20..00000000000 --- a/drivers/staging/zcache/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -zcache-y := zcache-main.o tmem.o - -obj-$(CONFIG_ZCACHE) += zcache.o diff --git a/drivers/staging/zcache/tmem.c b/drivers/staging/zcache/tmem.c deleted file mode 100644 index 56c8e606ad1..00000000000 --- a/drivers/staging/zcache/tmem.c +++ /dev/null @@ -1,773 +0,0 @@ -/* - * In-kernel transcendent memory (generic implementation) - * - * Copyright (c) 2009-2011, Dan Magenheimer, Oracle Corp. - * - * The primary purpose of Transcendent Memory ("tmem") is to map object-oriented - * "handles" (triples containing a pool id, and object id, and an index), to - * pages in a page-accessible memory (PAM). Tmem references the PAM pages via - * an abstract "pampd" (PAM page-descriptor), which can be operated on by a - * set of functions (pamops). Each pampd contains some representation of - * PAGE_SIZE bytes worth of data. Tmem must support potentially millions of - * pages and must be able to insert, find, and delete these pages at a - * potential frequency of thousands per second concurrently across many CPUs, - * (and, if used with KVM, across many vcpus across many guests). - * Tmem is tracked with a hierarchy of data structures, organized by - * the elements in a handle-tuple: pool_id, object_id, and page index. - * One or more "clients" (e.g. guests) each provide one or more tmem_pools. - * Each pool, contains a hash table of rb_trees of tmem_objs. Each - * tmem_obj contains a radix-tree-like tree of pointers, with intermediate - * nodes called tmem_objnodes. Each leaf pointer in this tree points to - * a pampd, which is accessible only through a small set of callbacks - * registered by the PAM implementation (see tmem_register_pamops). Tmem - * does all memory allocation via a set of callbacks registered by the tmem - * host implementation (e.g. see tmem_register_hostops). - */ - -#include <linux/list.h> -#include <linux/spinlock.h> -#include <linux/atomic.h> - -#include "tmem.h" - -/* data structure sentinels used for debugging... see tmem.h */ -#define POOL_SENTINEL 0x87658765 -#define OBJ_SENTINEL 0x12345678 -#define OBJNODE_SENTINEL 0xfedcba09 - -/* - * A tmem host implementation must use this function to register callbacks - * for memory allocation. - */ -static struct tmem_hostops tmem_hostops; - -static void tmem_objnode_tree_init(void); - -void tmem_register_hostops(struct tmem_hostops *m) -{ - tmem_objnode_tree_init(); - tmem_hostops = *m; -} - -/* - * A tmem host implementation must use this function to register - * callbacks for a page-accessible memory (PAM) implementation - */ -static struct tmem_pamops tmem_pamops; - -void tmem_register_pamops(struct tmem_pamops *m) -{ - tmem_pamops = *m; -} - -/* - * Oid's are potentially very sparse and tmem_objs may have an indeterminately - * short life, being added and deleted at a relatively high frequency. - * So an rb_tree is an ideal data structure to manage tmem_objs. But because - * of the potentially huge number of tmem_objs, each pool manages a hashtable - * of rb_trees to reduce search, insert, delete, and rebalancing time. - * Each hashbucket also has a lock to manage concurrent access. - * - * The following routines manage tmem_objs. When any tmem_obj is accessed, - * the hashbucket lock must be held. - */ - -static struct tmem_obj -*__tmem_obj_find(struct tmem_hashbucket*hb, struct tmem_oid *oidp, - struct rb_node **parent, struct rb_node ***link) -{ - struct rb_node *_parent = NULL, **rbnode; - struct tmem_obj *obj = NULL; - - rbnode = &hb->obj_rb_root.rb_node; - while (*rbnode) { - BUG_ON(RB_EMPTY_NODE(*rbnode)); - _parent = *rbnode; - obj = rb_entry(*rbnode, struct tmem_obj, - rb_tree_node); - switch (tmem_oid_compare(oidp, &obj->oid)) { - case 0: /* equal */ - goto out; - case -1: - rbnode = &(*rbnode)->rb_left; - break; - case 1: - rbnode = &(*rbnode)->rb_right; - break; - } - } - - if (parent) - *parent = _parent; - if (link) - *link = rbnode; - - obj = NULL; -out: - return obj; -} - - -/* searches for object==oid in pool, returns locked object if found */ -static struct tmem_obj *tmem_obj_find(struct tmem_hashbucket *hb, - struct tmem_oid *oidp) -{ - return __tmem_obj_find(hb, oidp, NULL, NULL); -} - -static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *); - -/* free an object that has no more pampds in it */ -static void tmem_obj_free(struct tmem_obj *obj, struct tmem_hashbucket *hb) -{ - struct tmem_pool *pool; - - BUG_ON(obj == NULL); - ASSERT_SENTINEL(obj, OBJ); - BUG_ON(obj->pampd_count > 0); - pool = obj->pool; - BUG_ON(pool == NULL); - if (obj->objnode_tree_root != NULL) /* may be "stump" with no leaves */ - tmem_pampd_destroy_all_in_obj(obj); - BUG_ON(obj->objnode_tree_root != NULL); - BUG_ON((long)obj->objnode_count != 0); - atomic_dec(&pool->obj_count); - BUG_ON(atomic_read(&pool->obj_count) < 0); - INVERT_SENTINEL(obj, OBJ); - obj->pool = NULL; - tmem_oid_set_invalid(&obj->oid); - rb_erase(&obj->rb_tree_node, &hb->obj_rb_root); -} - -/* - * initialize, and insert an tmem_object_root (called only if find failed) - */ -static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb, - struct tmem_pool *pool, - struct tmem_oid *oidp) -{ - struct rb_root *root = &hb->obj_rb_root; - struct rb_node **new = NULL, *parent = NULL; - - BUG_ON(pool == NULL); - atomic_inc(&pool->obj_count); - obj->objnode_tree_height = 0; - obj->objnode_tree_root = NULL; - obj->pool = pool; - obj->oid = *oidp; - obj->objnode_count = 0; - obj->pampd_count = 0; - (*tmem_pamops.new_obj)(obj); - SET_SENTINEL(obj, OBJ); - - if (__tmem_obj_find(hb, oidp, &parent, &new)) - BUG(); - - rb_link_node(&obj->rb_tree_node, parent, new); - rb_insert_color(&obj->rb_tree_node, root); -} - -/* - * Tmem is managed as a set of tmem_pools with certain attributes, such as - * "ephemeral" vs "persistent". These attributes apply to all tmem_objs - * and all pampds that belong to a tmem_pool. A tmem_pool is created - * or deleted relatively rarely (for example, when a filesystem is - * mounted or unmounted. - */ - -/* flush all data from a pool and, optionally, free it */ -static void tmem_pool_flush(struct tmem_pool *pool, bool destroy) -{ - struct rb_node *rbnode; - struct tmem_obj *obj; - struct tmem_hashbucket *hb = &pool->hashbucket[0]; - int i; - - BUG_ON(pool == NULL); - for (i = 0; i < TMEM_HASH_BUCKETS; i++, hb++) { - spin_lock(&hb->lock); - rbnode = rb_first(&hb->obj_rb_root); - while (rbnode != NULL) { - obj = rb_entry(rbnode, struct tmem_obj, rb_tree_node); - rbnode = rb_next(rbnode); - tmem_pampd_destroy_all_in_obj(obj); - tmem_obj_free(obj, hb); - (*tmem_hostops.obj_free)(obj, pool); - } - spin_unlock(&hb->lock); - } - if (destroy) - list_del(&pool->pool_list); -} - -/* - * A tmem_obj contains a radix-tree-like tree in which the intermediate - * nodes are called tmem_objnodes. (The kernel lib/radix-tree.c implementation - * is very specialized and tuned for specific uses and is not particularly - * suited for use from this code, though some code from the core algorithms has - * been reused, thus the copyright notices below). Each tmem_objnode contains - * a set of pointers which point to either a set of intermediate tmem_objnodes - * or a set of of pampds. - * - * Portions Copyright (C) 2001 Momchil Velikov - * Portions Copyright (C) 2001 Christoph Hellwig - * Portions Copyright (C) 2005 SGI, Christoph Lameter <clameter@sgi.com> - */ - -struct tmem_objnode_tree_path { - struct tmem_objnode *objnode; - int offset; -}; - -/* objnode height_to_maxindex translation */ -static unsigned long tmem_objnode_tree_h2max[OBJNODE_TREE_MAX_PATH + 1]; - -static void tmem_objnode_tree_init(void) -{ - unsigned int ht, tmp; - - for (ht = 0; ht < ARRAY_SIZE(tmem_objnode_tree_h2max); ht++) { - tmp = ht * OBJNODE_TREE_MAP_SHIFT; - if (tmp >= OBJNODE_TREE_INDEX_BITS) - tmem_objnode_tree_h2max[ht] = ~0UL; - else - tmem_objnode_tree_h2max[ht] = - (~0UL >> (OBJNODE_TREE_INDEX_BITS - tmp - 1)) >> 1; - } -} - -static struct tmem_objnode *tmem_objnode_alloc(struct tmem_obj *obj) -{ - struct tmem_objnode *objnode; - - ASSERT_SENTINEL(obj, OBJ); - BUG_ON(obj->pool == NULL); - ASSERT_SENTINEL(obj->pool, POOL); - objnode = (*tmem_hostops.objnode_alloc)(obj->pool); - if (unlikely(objnode == NULL)) - goto out; - objnode->obj = obj; - SET_SENTINEL(objnode, OBJNODE); - memset(&objnode->slots, 0, sizeof(objnode->slots)); - objnode->slots_in_use = 0; - obj->objnode_count++; -out: - return objnode; -} - -static void tmem_objnode_free(struct tmem_objnode *objnode) -{ - struct tmem_pool *pool; - int i; - - BUG_ON(objnode == NULL); - for (i = 0; i < OBJNODE_TREE_MAP_SIZE; i++) - BUG_ON(objnode->slots[i] != NULL); - ASSERT_SENTINEL(objnode, OBJNODE); - INVERT_SENTINEL(objnode, OBJNODE); - BUG_ON(objnode->obj == NULL); - ASSERT_SENTINEL(objnode->obj, OBJ); - pool = objnode->obj->pool; - BUG_ON(pool == NULL); - ASSERT_SENTINEL(pool, POOL); - objnode->obj->objnode_count--; - objnode->obj = NULL; - (*tmem_hostops.objnode_free)(objnode, pool); -} - -/* - * 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) -{ - unsigned int height, shift; - struct tmem_objnode **slot = NULL; - - BUG_ON(obj == NULL); - ASSERT_SENTINEL(obj, OBJ); - BUG_ON(obj->pool == NULL); - ASSERT_SENTINEL(obj->pool, POOL); - - height = obj->objnode_tree_height; - if (index > tmem_objnode_tree_h2max[obj->objnode_tree_height]) - goto out; - if (height == 0 && obj->objnode_tree_root) { - slot = &obj->objnode_tree_root; - goto out; - } - shift = (height-1) * OBJNODE_TREE_MAP_SHIFT; - slot = &obj->objnode_tree_root; - while (height > 0) { - if (*slot == NULL) - goto out; - slot = (struct tmem_objnode **) - ((*slot)->slots + - ((index >> shift) & OBJNODE_TREE_MAP_MASK)); - shift -= OBJNODE_TREE_MAP_SHIFT; - 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) -{ - int ret = 0; - struct tmem_objnode *objnode = NULL, *newnode, *slot; - unsigned int height, shift; - int offset = 0; - - /* if necessary, extend the tree to be higher */ - if (index > tmem_objnode_tree_h2max[obj->objnode_tree_height]) { - height = obj->objnode_tree_height + 1; - if (index > tmem_objnode_tree_h2max[height]) - while (index > tmem_objnode_tree_h2max[height]) - height++; - if (obj->objnode_tree_root == NULL) { - obj->objnode_tree_height = height; - goto insert; - } - do { - newnode = tmem_objnode_alloc(obj); - if (!newnode) { - ret = -ENOMEM; - goto out; - } - newnode->slots[0] = obj->objnode_tree_root; - newnode->slots_in_use = 1; - obj->objnode_tree_root = newnode; - obj->objnode_tree_height++; - } while (height > obj->objnode_tree_height); - } -insert: - slot = obj->objnode_tree_root; - height = obj->objnode_tree_height; - shift = (height-1) * OBJNODE_TREE_MAP_SHIFT; - while (height > 0) { - if (slot == NULL) { - /* add a child objnode. */ - slot = tmem_objnode_alloc(obj); - if (!slot) { - ret = -ENOMEM; - goto out; - } - if (objnode) { - - objnode->slots[offset] = slot; - objnode->slots_in_use++; - } else - obj->objnode_tree_root = slot; - } - /* go down a level */ - offset = (index >> shift) & OBJNODE_TREE_MAP_MASK; - objnode = slot; - slot = objnode->slots[offset]; - shift -= OBJNODE_TREE_MAP_SHIFT; - height--; - } - BUG_ON(slot != NULL); - if (objnode) { - objnode->slots_in_use++; - objnode->slots[offset] = pampd; - } else - obj->objnode_tree_root = pampd; - obj->pampd_count++; -out: - return ret; -} - -static void *tmem_pampd_delete_from_obj(struct tmem_obj *obj, uint32_t index) -{ - struct tmem_objnode_tree_path path[OBJNODE_TREE_MAX_PATH + 1]; - struct tmem_objnode_tree_path *pathp = path; - struct tmem_objnode *slot = NULL; - unsigned int height, shift; - int offset; - - BUG_ON(obj == NULL); - ASSERT_SENTINEL(obj, OBJ); - BUG_ON(obj->pool == NULL); - ASSERT_SENTINEL(obj->pool, POOL); - height = obj->objnode_tree_height; - if (index > tmem_objnode_tree_h2max[height]) - goto out; - slot = obj->objnode_tree_root; - if (height == 0 && obj->objnode_tree_root) { - obj->objnode_tree_root = NULL; - goto out; - } - shift = (height - 1) * OBJNODE_TREE_MAP_SHIFT; - pathp->objnode = NULL; - do { - if (slot == NULL) - goto out; - pathp++; - offset = (index >> shift) & OBJNODE_TREE_MAP_MASK; - pathp->offset = offset; - pathp->objnode = slot; - slot = slot->slots[offset]; - shift -= OBJNODE_TREE_MAP_SHIFT; - height--; - } while (height > 0); - if (slot == NULL) - goto out; - while (pathp->objnode) { - pathp->objnode->slots[pathp->offset] = NULL; - pathp->objnode->slots_in_use--; - if (pathp->objnode->slots_in_use) { - if (pathp->objnode == obj->objnode_tree_root) { - while (obj->objnode_tree_height > 0 && - obj->objnode_tree_root->slots_in_use == 1 && - obj->objnode_tree_root->slots[0]) { - struct tmem_objnode *to_free = - obj->objnode_tree_root; - - obj->objnode_tree_root = - to_free->slots[0]; - obj->objnode_tree_height--; - to_free->slots[0] = NULL; - to_free->slots_in_use = 0; - tmem_objnode_free(to_free); - } - } - goto out; - } - tmem_objnode_free(pathp->objnode); /* 0 slots used, free it */ - pathp--; - } - obj->objnode_tree_height = 0; - obj->objnode_tree_root = NULL; - -out: - if (slot != NULL) - obj->pampd_count--; - BUG_ON(obj->pampd_count < 0); - return slot; -} - -/* recursively walk the objnode_tree destroying pampds and objnodes */ -static void tmem_objnode_node_destroy(struct tmem_obj *obj, - struct tmem_objnode *objnode, - unsigned int ht) -{ - int i; - - if (ht == 0) - return; - for (i = 0; i < OBJNODE_TREE_MAP_SIZE; i++) { - if (objnode->slots[i]) { - if (ht == 1) { - obj->pampd_count--; - (*tmem_pamops.free)(objnode->slots[i], - obj->pool, NULL, 0); - objnode->slots[i] = NULL; - continue; - } - tmem_objnode_node_destroy(obj, objnode->slots[i], ht-1); - tmem_objnode_free(objnode->slots[i]); - objnode->slots[i] = NULL; - } - } -} - -static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj) -{ - if (obj->objnode_tree_root == NULL) - return; - if (obj->objnode_tree_height == 0) { - obj->pampd_count--; - (*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); - tmem_objnode_free(obj->objnode_tree_root); - obj->objnode_tree_height = 0; - } - obj->objnode_tree_root = NULL; - (*tmem_pamops.free_obj)(obj->pool, obj); -} - -/* - * Tmem is operated on by a set of well-defined actions: - * "put", "get", "flush", "flush_object", "new pool" and "destroy pool". - * (The tmem ABI allows for subpages and exchanges but these operations - * are not included in this implementation.) - * - * These "tmem core" operations are implemented in the following functions. - */ - -/* - * "Put" a page, e.g. copy a page from the kernel into newly allocated - * PAM space (if such space is available). Tmem_put is complicated by - * a corner case: What if a page with matching handle already exists in - * tmem? To guarantee coherency, one of two actions is necessary: Either - * the data for the page must be overwritten, or the page must be - * "flushed" so that the data is not accessible to a subsequent "get". - * Since these "duplicate puts" are relatively rare, this implementation - * always flushes for simplicity. - */ -int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index, - 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; - struct tmem_hashbucket *hb; - - hb = &pool->hashbucket[tmem_oid_hash(oidp)]; - spin_lock(&hb->lock); - obj = objfound = tmem_obj_find(hb, oidp); - if (obj != NULL) { - pampd = tmem_pampd_lookup_in_obj(objfound, index); - if (pampd != NULL) { - /* 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, oidp, index); - if (obj->pampd_count == 0) { - objnew = obj; - objfound = NULL; - } - pampd = NULL; - } - } else { - obj = objnew = (*tmem_hostops.obj_alloc)(pool); - if (unlikely(obj == NULL)) { - ret = -ENOMEM; - goto out; - } - tmem_obj_init(obj, hb, pool, oidp); - } - BUG_ON(obj == NULL); - BUG_ON(((objnew != obj) && (objfound != obj)) || (objnew == objfound)); - 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); - if (unlikely(ret == -ENOMEM)) - /* may have partially built objnode tree ("stump") */ - goto delete_and_free; - goto out; - -delete_and_free: - (void)tmem_pampd_delete_from_obj(obj, index); -free: - if (pampd) - (*tmem_pamops.free)(pampd, pool, NULL, 0); - if (objnew) { - tmem_obj_free(objnew, hb); - (*tmem_hostops.obj_free)(objnew, pool); - } -out: - spin_unlock(&hb->lock); - return ret; -} - -/* - * "Get" a page, e.g. if one can be found, copy the tmem page with the - * matching handle from PAM space to the kernel. By tmem definition, - * when a "get" is successful on an ephemeral page, the page is "flushed", - * and when a "get" is successful on a persistent page, the page is retained - * in tmem. Note that to preserve - * coherency, "get" can never be skipped if tmem contains the data. - * That is, if a get is done with a certain handle and fails, any - * subsequent "get" must also fail (unless of course there is a - * "put" done with the same handle). - - */ -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); - int 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; - if (free) - pampd = tmem_pampd_delete_from_obj(obj, index); - else - pampd = tmem_pampd_lookup_in_obj(obj, index); - if (pampd == NULL) - goto out; - 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: - if (lock_held) - spin_unlock(&hb->lock); - return ret; -} - -/* - * If a page in tmem matches the handle, "flush" this page from tmem such - * that any subsequent "get" does not succeed (unless, of course, there - * was another "put" with the same handle). - */ -int tmem_flush_page(struct tmem_pool *pool, - struct tmem_oid *oidp, uint32_t index) -{ - struct tmem_obj *obj; - void *pampd; - 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; - pampd = tmem_pampd_delete_from_obj(obj, index); - if (pampd == NULL) - goto out; - (*tmem_pamops.free)(pampd, pool, oidp, index); - if (obj->pampd_count == 0) { - tmem_obj_free(obj, hb); - (*tmem_hostops.obj_free)(obj, pool); - } - ret = 0; - -out: - spin_unlock(&hb->lock); - 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. - */ -int tmem_flush_object(struct tmem_pool *pool, struct tmem_oid *oidp) -{ - struct tmem_obj *obj; - struct tmem_hashbucket *hb; - int ret = -1; - - hb = &pool->hashbucket[tmem_oid_hash(oidp)]; - spin_lock(&hb->lock); - obj = tmem_obj_find(hb, oidp); - if (obj == NULL) - goto out; - tmem_pampd_destroy_all_in_obj(obj); - tmem_obj_free(obj, hb); - (*tmem_hostops.obj_free)(obj, pool); - ret = 0; - -out: - spin_unlock(&hb->lock); - return ret; -} - -/* - * "Flush" all pages (and tmem_objs) from this tmem_pool and disable - * all subsequent access to this tmem_pool. - */ -int tmem_destroy_pool(struct tmem_pool *pool) -{ - int ret = -1; - - if (pool == NULL) - goto out; - tmem_pool_flush(pool, 1); - ret = 0; -out: - return ret; -} - -static LIST_HEAD(tmem_global_pool_list); - -/* - * Create a new tmem_pool with the provided flag and return - * a pool id provided by the tmem host implementation. - */ -void tmem_new_pool(struct tmem_pool *pool, uint32_t flags) -{ - int persistent = flags & TMEM_POOL_PERSIST; - int shared = flags & TMEM_POOL_SHARED; - struct tmem_hashbucket *hb = &pool->hashbucket[0]; - int i; - - for (i = 0; i < TMEM_HASH_BUCKETS; i++, hb++) { - hb->obj_rb_root = RB_ROOT; - spin_lock_init(&hb->lock); - } - INIT_LIST_HEAD(&pool->pool_list); - atomic_set(&pool->obj_count, 0); - SET_SENTINEL(pool, POOL); - list_add_tail(&pool->pool_list, &tmem_global_pool_list); - pool->persistent = persistent; - pool->shared = shared; -} diff --git a/drivers/staging/zcache/tmem.h b/drivers/staging/zcache/tmem.h deleted file mode 100644 index 0d4aa82706b..00000000000 --- a/drivers/staging/zcache/tmem.h +++ /dev/null @@ -1,206 +0,0 @@ -/* - * tmem.h - * - * Transcendent memory - * - * Copyright (c) 2009-2011, Dan Magenheimer, Oracle Corp. - */ - -#ifndef _TMEM_H_ -#define _TMEM_H_ - -#include <linux/types.h> -#include <linux/highmem.h> -#include <linux/hash.h> -#include <linux/atomic.h> - -/* - * These are pre-defined by the Xen<->Linux ABI - */ -#define TMEM_PUT_PAGE 4 -#define TMEM_GET_PAGE 5 -#define TMEM_FLUSH_PAGE 6 -#define TMEM_FLUSH_OBJECT 7 -#define TMEM_POOL_PERSIST 1 -#define TMEM_POOL_SHARED 2 -#define TMEM_POOL_PRECOMPRESSED 4 -#define TMEM_POOL_PAGESIZE_SHIFT 4 -#define TMEM_POOL_PAGESIZE_MASK 0xf -#define TMEM_POOL_RESERVED_BITS 0x00ffff00 - -/* - * sentinels have proven very useful for debugging but can be removed - * or disabled before final merge. - */ -#define SENTINELS -#ifdef SENTINELS -#define DECL_SENTINEL uint32_t sentinel; -#define SET_SENTINEL(_x, _y) (_x->sentinel = _y##_SENTINEL) -#define INVERT_SENTINEL(_x, _y) (_x->sentinel = ~_y##_SENTINEL) -#define ASSERT_SENTINEL(_x, _y) WARN_ON(_x->sentinel != _y##_SENTINEL) -#define ASSERT_INVERTED_SENTINEL(_x, _y) WARN_ON(_x->sentinel != ~_y##_SENTINEL) -#else -#define DECL_SENTINEL -#define SET_SENTINEL(_x, _y) do { } while (0) -#define INVERT_SENTINEL(_x, _y) do { } while (0) -#define ASSERT_SENTINEL(_x, _y) do { } while (0) -#define ASSERT_INVERTED_SENTINEL(_x, _y) do { } while (0) -#endif - -#define ASSERT_SPINLOCK(_l) lockdep_assert_held(_l) - -/* - * A pool is the highest-level data structure managed by tmem and - * usually corresponds to a large independent set of pages such as - * a filesystem. Each pool has an id, and certain attributes and counters. - * It also contains a set of hash buckets, each of which contains an rbtree - * of objects and a lock to manage concurrency within the pool. - */ - -#define TMEM_HASH_BUCKET_BITS 8 -#define TMEM_HASH_BUCKETS (1<<TMEM_HASH_BUCKET_BITS) - -struct tmem_hashbucket { - struct rb_root obj_rb_root; - spinlock_t lock; -}; - -struct tmem_pool { - void *client; /* "up" for some clients, avoids table lookup */ - struct list_head pool_list; - uint32_t pool_id; - bool persistent; - bool shared; - atomic_t obj_count; - atomic_t refcount; - struct tmem_hashbucket hashbucket[TMEM_HASH_BUCKETS]; - DECL_SENTINEL -}; - -#define is_persistent(_p) (_p->persistent) -#define is_ephemeral(_p) (!(_p->persistent)) - -/* - * An object id ("oid") is large: 192-bits (to ensure, for example, files - * in a modern filesystem can be uniquely identified). - */ - -struct tmem_oid { - uint64_t oid[3]; -}; - -static inline void tmem_oid_set_invalid(struct tmem_oid *oidp) -{ - oidp->oid[0] = oidp->oid[1] = oidp->oid[2] = -1UL; -} - -static inline bool tmem_oid_valid(struct tmem_oid *oidp) -{ - return oidp->oid[0] != -1UL || oidp->oid[1] != -1UL || - oidp->oid[2] != -1UL; -} - -static inline int tmem_oid_compare(struct tmem_oid *left, - struct tmem_oid *right) -{ - int ret; - - if (left->oid[2] == right->oid[2]) { - if (left->oid[1] == right->oid[1]) { - if (left->oid[0] == right->oid[0]) - ret = 0; - else if (left->oid[0] < right->oid[0]) - ret = -1; - else - return 1; - } else if (left->oid[1] < right->oid[1]) - ret = -1; - else - ret = 1; - } else if (left->oid[2] < right->oid[2]) - ret = -1; - else - ret = 1; - return ret; -} - -static inline unsigned tmem_oid_hash(struct tmem_oid *oidp) -{ - return hash_long(oidp->oid[0] ^ oidp->oid[1] ^ oidp->oid[2], - TMEM_HASH_BUCKET_BITS); -} - -/* - * A tmem_obj contains an identifier (oid), pointers to the parent - * pool and the rb_tree to which it belongs, counters, and an ordered - * set of pampds, structured in a radix-tree-like tree. The intermediate - * nodes of the tree are called tmem_objnodes. - */ - -struct tmem_objnode; - -struct tmem_obj { - struct tmem_oid oid; - struct tmem_pool *pool; - struct rb_node rb_tree_node; - struct tmem_objnode *objnode_tree_root; - unsigned int objnode_tree_height; - unsigned long objnode_count; - long pampd_count; - void *extra; /* for private use by pampd implementation */ - DECL_SENTINEL -}; - -#define OBJNODE_TREE_MAP_SHIFT 6 -#define OBJNODE_TREE_MAP_SIZE (1UL << OBJNODE_TREE_MAP_SHIFT) -#define OBJNODE_TREE_MAP_MASK (OBJNODE_TREE_MAP_SIZE-1) -#define OBJNODE_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long)) -#define OBJNODE_TREE_MAX_PATH \ - (OBJNODE_TREE_INDEX_BITS/OBJNODE_TREE_MAP_SHIFT + 2) - -struct tmem_objnode { - struct tmem_obj *obj; - DECL_SENTINEL - void *slots[OBJNODE_TREE_MAP_SIZE]; - unsigned int slots_in_use; -}; - -/* pampd abstract datatype methods provided by the PAM implementation */ -struct tmem_pamops { - void *(*create)(char *, size_t, bool, int, - struct tmem_pool *, struct tmem_oid *, uint32_t); - int (*get_data)(char *, size_t *, bool, void *, struct tmem_pool *, - struct tmem_oid *, uint32_t); - int (*get_data_and_free)(char *, size_t *, bool, void *, - struct tmem_pool *, struct tmem_oid *, - uint32_t); - void (*free)(void *, struct tmem_pool *, struct tmem_oid *, uint32_t); - void (*free_obj)(struct tmem_pool *, struct tmem_obj *); - bool (*is_remote)(void *); - void (*new_obj)(struct tmem_obj *); - int (*replace_in_obj)(void *, struct tmem_obj *); -}; -extern void tmem_register_pamops(struct tmem_pamops *m); - -/* memory allocation methods provided by the host implementation */ -struct tmem_hostops { - struct tmem_obj *(*obj_alloc)(struct tmem_pool *); - void (*obj_free)(struct tmem_obj *, struct tmem_pool *); - struct tmem_objnode *(*objnode_alloc)(struct tmem_pool *); - void (*objnode_free)(struct tmem_objnode *, struct tmem_pool *); -}; -extern void tmem_register_hostops(struct tmem_hostops *m); - -/* core tmem accessor functions */ -extern int tmem_put(struct tmem_pool *, struct tmem_oid *, uint32_t index, - char *, size_t, bool, bool); -extern int tmem_get(struct tmem_pool *, struct tmem_oid *, uint32_t index, - char *, size_t *, bool, int); -extern int tmem_replace(struct tmem_pool *, struct tmem_oid *, uint32_t index, - void *); -extern int tmem_flush_page(struct tmem_pool *, struct tmem_oid *, - uint32_t index); -extern int tmem_flush_object(struct tmem_pool *, struct tmem_oid *); -extern int tmem_destroy_pool(struct tmem_pool *); -extern void tmem_new_pool(struct tmem_pool *, uint32_t); -#endif /* _TMEM_H */ diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c deleted file mode 100644 index 52b43b7b83d..00000000000 --- a/drivers/staging/zcache/zcache-main.c +++ /dev/null @@ -1,2077 +0,0 @@ -/* - * zcache.c - * - * Copyright (c) 2010,2011, Dan Magenheimer, Oracle Corp. - * Copyright (c) 2010,2011, Nitin Gupta - * - * Zcache provides an in-kernel "host implementation" for transcendent memory - * and, thus indirectly, for cleancache and frontswap. Zcache includes two - * page-accessible memory [1] interfaces, both utilizing the crypto compression - * API: - * 1) "compression buddies" ("zbud") is used for ephemeral pages - * 2) zsmalloc is used for persistent pages. - * Xvmalloc (based on the TLSF allocator) has very low fragmentation - * so maximizes space efficiency, while zbud allows pairs (and potentially, - * in the future, more than a pair of) compressed pages to be closely linked - * so that reclaiming can be done via the kernel's physical-page-oriented - * "shrinker" interface. - * - * [1] For a definition of page-accessible memory (aka PAM), see: - * http://marc.info/?l=linux-mm&m=127811271605009 - */ - -#include <linux/module.h> -#include <linux/cpu.h> -#include <linux/highmem.h> -#include <linux/list.h> -#include <linux/slab.h> -#include <linux/spinlock.h> -#include <linux/types.h> -#include <linux/atomic.h> -#include <linux/math64.h> -#include <linux/crypto.h> -#include <linux/string.h> -#include <linux/idr.h> -#include "tmem.h" - -#include "../zsmalloc/zsmalloc.h" - -#ifdef CONFIG_CLEANCACHE -#include <linux/cleancache.h> -#endif -#ifdef CONFIG_FRONTSWAP -#include <linux/frontswap.h> -#endif - -#if 0 -/* this is more aggressive but may cause other problems? */ -#define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN) -#else -#define ZCACHE_GFP_MASK \ - (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC) -#endif - -#define MAX_CLIENTS 16 -#define LOCAL_CLIENT ((uint16_t)-1) - -MODULE_LICENSE("GPL"); - -struct zcache_client { - struct idr tmem_pools; - struct zs_pool *zspool; - bool allocated; - atomic_t refcount; -}; - -static struct zcache_client zcache_host; -static struct zcache_client zcache_clients[MAX_CLIENTS]; - -static inline uint16_t get_client_id_from_client(struct zcache_client *cli) -{ - BUG_ON(cli == NULL); - if (cli == &zcache_host) - return LOCAL_CLIENT; - return cli - &zcache_clients[0]; -} - -static struct zcache_client *get_zcache_client(uint16_t cli_id) -{ - if (cli_id == LOCAL_CLIENT) - return &zcache_host; - - if ((unsigned int)cli_id < MAX_CLIENTS) - return &zcache_clients[cli_id]; - - return NULL; -} - -static inline bool is_local_client(struct zcache_client *cli) -{ - return cli == &zcache_host; -} - -/* crypto API for zcache */ -#define ZCACHE_COMP_NAME_SZ CRYPTO_MAX_ALG_NAME -static char zcache_comp_name[ZCACHE_COMP_NAME_SZ]; -static struct crypto_comp * __percpu *zcache_comp_pcpu_tfms; - -enum comp_op { - ZCACHE_COMPOP_COMPRESS, - ZCACHE_COMPOP_DECOMPRESS -}; - -static inline int zcache_comp_op(enum comp_op op, - const u8 *src, unsigned int slen, - u8 *dst, unsigned int *dlen) -{ - struct crypto_comp *tfm; - int ret; - - BUG_ON(!zcache_comp_pcpu_tfms); - tfm = *per_cpu_ptr(zcache_comp_pcpu_tfms, get_cpu()); - BUG_ON(!tfm); - switch (op) { - case ZCACHE_COMPOP_COMPRESS: - ret = crypto_comp_compress(tfm, src, slen, dst, dlen); - break; - case ZCACHE_COMPOP_DECOMPRESS: - ret = crypto_comp_decompress(tfm, src, slen, dst, dlen); - break; - default: - ret = -EINVAL; - } - put_cpu(); - return ret; -} - -/********** - * Compression buddies ("zbud") provides for packing two (or, possibly - * in the future, more) compressed ephemeral pages into a single "raw" - * (physical) page and tracking them with data structures so that - * the raw pages can be easily reclaimed. - * - * A zbud page ("zbpg") is an aligned page containing a list_head, - * a lock, and two "zbud headers". The remainder of the physical - * page is divided up into aligned 64-byte "chunks" which contain - * the compressed data for zero, one, or two zbuds. Each zbpg - * resides on: (1) an "unused list" if it has no zbuds; (2) a - * "buddied" list if it is fully populated with two zbuds; or - * (3) one of PAGE_SIZE/64 "unbuddied" lists indexed by how many chunks - * the one unbuddied zbud uses. The data inside a zbpg cannot be - * read or written unless the zbpg's lock is held. - */ - -#define ZBH_SENTINEL 0x43214321 -#define ZBPG_SENTINEL 0xdeadbeef - -#define ZBUD_MAX_BUDS 2 - -struct zbud_hdr { - uint16_t client_id; - uint16_t pool_id; - struct tmem_oid oid; - uint32_t index; - uint16_t size; /* compressed size in bytes, zero means unused */ - DECL_SENTINEL -}; - -struct zbud_page { - struct list_head bud_list; - spinlock_t lock; - struct zbud_hdr buddy[ZBUD_MAX_BUDS]; - DECL_SENTINEL - /* followed by NUM_CHUNK aligned CHUNK_SIZE-byte chunks */ -}; - -#define CHUNK_SHIFT 6 -#define CHUNK_SIZE (1 << CHUNK_SHIFT) -#define CHUNK_MASK (~(CHUNK_SIZE-1)) -#define NCHUNKS (((PAGE_SIZE - sizeof(struct zbud_page)) & \ - CHUNK_MASK) >> CHUNK_SHIFT) -#define MAX_CHUNK (NCHUNKS-1) - -static struct { - struct list_head list; - unsigned count; -} zbud_unbuddied[NCHUNKS]; -/* list N contains pages with N chunks USED and NCHUNKS-N unused */ -/* element 0 is never used but optimizing that isn't worth it */ -static unsigned long zbud_cumul_chunk_counts[NCHUNKS]; - -struct list_head zbud_buddied_list; -static unsigned long zcache_zbud_buddied_count; - -/* protects the buddied list and all unbuddied lists */ -static DEFINE_SPINLOCK(zbud_budlists_spinlock); - -static LIST_HEAD(zbpg_unused_list); -static unsigned long zcache_zbpg_unused_list_count; - -/* protects the unused page list */ -static DEFINE_SPINLOCK(zbpg_unused_list_spinlock); - -static atomic_t zcache_zbud_curr_raw_pages; -static atomic_t zcache_zbud_curr_zpages; -static unsigned long zcache_zbud_curr_zbytes; -static unsigned long zcache_zbud_cumul_zpages; -static unsigned long zcache_zbud_cumul_zbytes; -static unsigned long zcache_compress_poor; -static unsigned long zcache_mean_compress_poor; - -/* forward references */ -static void *zcache_get_free_page(void); -static void zcache_free_page(void *p); - -/* - * zbud helper functions - */ - -static inline unsigned zbud_max_buddy_size(void) -{ - return MAX_CHUNK << CHUNK_SHIFT; -} - -static inline unsigned zbud_size_to_chunks(unsigned size) -{ - BUG_ON(size == 0 || size > zbud_max_buddy_size()); - return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT; -} - -static inline int zbud_budnum(struct zbud_hdr *zh) -{ - unsigned offset = (unsigned long)zh & (PAGE_SIZE - 1); - struct zbud_page *zbpg = NULL; - unsigned budnum = -1U; - int i; - - for (i = 0; i < ZBUD_MAX_BUDS; i++) - if (offset == offsetof(typeof(*zbpg), buddy[i])) { - budnum = i; - break; - } - BUG_ON(budnum == -1U); - return budnum; -} - -static char *zbud_data(struct zbud_hdr *zh, unsigned size) -{ - struct zbud_page *zbpg; - char *p; - unsigned budnum; - - ASSERT_SENTINEL(zh, ZBH); - budnum = zbud_budnum(zh); - BUG_ON(size == 0 || size > zbud_max_buddy_size()); - zbpg = container_of(zh, struct zbud_page, buddy[budnum]); - ASSERT_SPINLOCK(&zbpg->lock); - p = (char *)zbpg; - if (budnum == 0) - p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) & - CHUNK_MASK); - else if (budnum == 1) - p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK); - return p; -} - -/* - * zbud raw page management - */ - -static struct zbud_page *zbud_alloc_raw_page(void) -{ - struct zbud_page *zbpg = NULL; - struct zbud_hdr *zh0, *zh1; - bool recycled = 0; - - /* if any pages on the zbpg list, use one */ - spin_lock(&zbpg_unused_list_spinlock); - if (!list_empty(&zbpg_unused_list)) { - zbpg = list_first_entry(&zbpg_unused_list, - struct zbud_page, bud_list); - list_del_init(&zbpg->bud_list); - zcache_zbpg_unused_list_count--; - recycled = 1; - } - spin_unlock(&zbpg_unused_list_spinlock); - if (zbpg == NULL) - /* none on zbpg list, try to get a kernel page */ - zbpg = zcache_get_free_page(); - if (likely(zbpg != NULL)) { - INIT_LIST_HEAD(&zbpg->bud_list); - zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; - spin_lock_init(&zbpg->lock); - if (recycled) { - ASSERT_INVERTED_SENTINEL(zbpg, ZBPG); - SET_SENTINEL(zbpg, ZBPG); - BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); - BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); - } else { - atomic_inc(&zcache_zbud_curr_raw_pages); - INIT_LIST_HEAD(&zbpg->bud_list); - SET_SENTINEL(zbpg, ZBPG); - zh0->size = 0; zh1->size = 0; - tmem_oid_set_invalid(&zh0->oid); - tmem_oid_set_invalid(&zh1->oid); - } - } - return zbpg; -} - -static void zbud_free_raw_page(struct zbud_page *zbpg) -{ - struct zbud_hdr *zh0 = &zbpg->buddy[0], *zh1 = &zbpg->buddy[1]; - - ASSERT_SENTINEL(zbpg, ZBPG); - BUG_ON(!list_empty(&zbpg->bud_list)); - ASSERT_SPINLOCK(&zbpg->lock); - BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); - BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); - INVERT_SENTINEL(zbpg, ZBPG); - spin_unlock(&zbpg->lock); - spin_lock(&zbpg_unused_list_spinlock); - list_add(&zbpg->bud_list, &zbpg_unused_list); - zcache_zbpg_unused_list_count++; - spin_unlock(&zbpg_unused_list_spinlock); -} - -/* - * core zbud handling routines - */ - -static unsigned zbud_free(struct zbud_hdr *zh) -{ - unsigned size; - - ASSERT_SENTINEL(zh, ZBH); - BUG_ON(!tmem_oid_valid(&zh->oid)); - size = zh->size; - BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); - zh->size = 0; - tmem_oid_set_invalid(&zh->oid); - INVERT_SENTINEL(zh, ZBH); - zcache_zbud_curr_zbytes -= size; - atomic_dec(&zcache_zbud_curr_zpages); - return size; -} - -static void zbud_free_and_delist(struct zbud_hdr *zh) -{ - unsigned chunks; - struct zbud_hdr *zh_other; - unsigned budnum = zbud_budnum(zh), size; - struct zbud_page *zbpg = - container_of(zh, struct zbud_page, buddy[budnum]); - - spin_lock(&zbud_budlists_spinlock); - spin_lock(&zbpg->lock); - if (list_empty(&zbpg->bud_list)) { - /* ignore zombie page... see zbud_evict_pages() */ - spin_unlock(&zbpg->lock); - spin_unlock(&zbud_budlists_spinlock); - return; - } - size = zbud_free(zh); - ASSERT_SPINLOCK(&zbpg->lock); - zh_other = &zbpg->buddy[(budnum == 0) ? 1 : 0]; - if (zh_other->size == 0) { /* was unbuddied: unlist and free */ - chunks = zbud_size_to_chunks(size) ; - BUG_ON(list_empty(&zbud_unbuddied[chunks].list)); - list_del_init(&zbpg->bud_list); - zbud_unbuddied[chunks].count--; - spin_unlock(&zbud_budlists_spinlock); - zbud_free_raw_page(zbpg); - } else { /* was buddied: move remaining buddy to unbuddied list */ - chunks = zbud_size_to_chunks(zh_other->size) ; - list_del_init(&zbpg->bud_list); - zcache_zbud_buddied_count--; - list_add_tail(&zbpg->bud_list, &zbud_unbuddied[chunks].list); - zbud_unbuddied[chunks].count++; - spin_unlock(&zbud_budlists_spinlock); - spin_unlock(&zbpg->lock); - } -} - -static struct zbud_hdr *zbud_create(uint16_t client_id, uint16_t pool_id, - struct tmem_oid *oid, - uint32_t index, struct page *page, - void *cdata, unsigned size) -{ - struct zbud_hdr *zh0, *zh1, *zh = NULL; - struct zbud_page *zbpg = NULL, *ztmp; - unsigned nchunks; - char *to; - int i, found_good_buddy = 0; - - nchunks = zbud_size_to_chunks(size) ; - for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) { - spin_lock(&zbud_budlists_spinlock); - if (!list_empty(&zbud_unbuddied[i].list)) { - list_for_each_entry_safe(zbpg, ztmp, - &zbud_unbuddied[i].list, bud_list) { - if (spin_trylock(&zbpg->lock)) { - found_good_buddy = i; - goto found_unbuddied; - } - } - } - spin_unlock(&zbud_budlists_spinlock); - } - /* didn't find a good buddy, try allocating a new page */ - zbpg = zbud_alloc_raw_page(); - if (unlikely(zbpg == NULL)) - goto out; - /* ok, have a page, now compress the data before taking locks */ - spin_lock(&zbud_budlists_spinlock); - spin_lock(&zbpg->lock); - list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list); - zbud_unbuddied[nchunks].count++; - zh = &zbpg->buddy[0]; - goto init_zh; - -found_unbuddied: - ASSERT_SPINLOCK(&zbpg->lock); - zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; - BUG_ON(!((zh0->size == 0) ^ (zh1->size == 0))); - if (zh0->size != 0) { /* buddy0 in use, buddy1 is vacant */ - ASSERT_SENTINEL(zh0, ZBH); - zh = zh1; - } else if (zh1->size != 0) { /* buddy1 in use, buddy0 is vacant */ - ASSERT_SENTINEL(zh1, ZBH); - zh = zh0; - } else - BUG(); - list_del_init(&zbpg->bud_list); - zbud_unbuddied[found_good_buddy].count--; - list_add_tail(&zbpg->bud_list, &zbud_buddied_list); - zcache_zbud_buddied_count++; - -init_zh: - SET_SENTINEL(zh, ZBH); - zh->size = size; - zh->index = index; - zh->oid = *oid; - zh->pool_id = pool_id; - zh->client_id = client_id; - to = zbud_data(zh, size); - memcpy(to, cdata, size); - spin_unlock(&zbpg->lock); - spin_unlock(&zbud_budlists_spinlock); - - zbud_cumul_chunk_counts[nchunks]++; - atomic_inc(&zcache_zbud_curr_zpages); - zcache_zbud_cumul_zpages++; - zcache_zbud_curr_zbytes += size; - zcache_zbud_cumul_zbytes += size; -out: - return zh; -} - -static int zbud_decompress(struct page *page, struct zbud_hdr *zh) -{ - struct zbud_page *zbpg; - unsigned budnum = zbud_budnum(zh); - unsigned int out_len = PAGE_SIZE; - char *to_va, *from_va; - unsigned size; - int ret = 0; - - zbpg = container_of(zh, struct zbud_page, buddy[budnum]); - spin_lock(&zbpg->lock); - if (list_empty(&zbpg->bud_list)) { - /* ignore zombie page... see zbud_evict_pages() */ - ret = -EINVAL; - goto out; - } - ASSERT_SENTINEL(zh, ZBH); - BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); - to_va = kmap_atomic(page); - size = zh->size; - from_va = zbud_data(zh, size); - ret = zcache_comp_op(ZCACHE_COMPOP_DECOMPRESS, from_va, size, - to_va, &out_len); - BUG_ON(ret); - BUG_ON(out_len != PAGE_SIZE); - kunmap_atomic(to_va); -out: - spin_unlock(&zbpg->lock); - return ret; -} - -/* - * The following routines handle shrinking of ephemeral pages by evicting - * pages "least valuable" first. - */ - -static unsigned long zcache_evicted_raw_pages; -static unsigned long zcache_evicted_buddied_pages; -static unsigned long zcache_evicted_unbuddied_pages; - -static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, - uint16_t poolid); -static void zcache_put_pool(struct tmem_pool *pool); - -/* - * Flush and free all zbuds in a zbpg, then free the pageframe - */ -static void zbud_evict_zbpg(struct zbud_page *zbpg) -{ - struct zbud_hdr *zh; - int i, j; - uint32_t pool_id[ZBUD_MAX_BUDS], client_id[ZBUD_MAX_BUDS]; - uint32_t index[ZBUD_MAX_BUDS]; - struct tmem_oid oid[ZBUD_MAX_BUDS]; - struct tmem_pool *pool; - - ASSERT_SPINLOCK(&zbpg->lock); - BUG_ON(!list_empty(&zbpg->bud_list)); - for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) { - zh = &zbpg->buddy[i]; - if (zh->size) { - client_id[j] = zh->client_id; - pool_id[j] = zh->pool_id; - oid[j] = zh->oid; - index[j] = zh->index; - j++; - zbud_free(zh); - } - } - spin_unlock(&zbpg->lock); - for (i = 0; i < j; i++) { - pool = zcache_get_pool_by_id(client_id[i], pool_id[i]); - if (pool != NULL) { - tmem_flush_page(pool, &oid[i], index[i]); - zcache_put_pool(pool); - } - } - ASSERT_SENTINEL(zbpg, ZBPG); - spin_lock(&zbpg->lock); - zbud_free_raw_page(zbpg); -} - -/* - * Free nr pages. This code is funky because we want to hold the locks - * protecting various lists for as short a time as possible, and in some - * circumstances the list may change asynchronously when the list lock is - * not held. In some cases we also trylock not only to avoid waiting on a - * page in use by another cpu, but also to avoid potential deadlock due to - * lock inversion. - */ -static void zbud_evict_pages(int nr) -{ - struct zbud_page *zbpg; - int i; - - /* first try freeing any pages on unused list */ -retry_unused_list: - spin_lock_bh(&zbpg_unused_list_spinlock); - if (!list_empty(&zbpg_unused_list)) { - /* can't walk list here, since it may change when unlocked */ - zbpg = list_first_entry(&zbpg_unused_list, - struct zbud_page, bud_list); - list_del_init(&zbpg->bud_list); - zcache_zbpg_unused_list_count--; - atomic_dec(&zcache_zbud_curr_raw_pages); - spin_unlock_bh(&zbpg_unused_list_spinlock); - zcache_free_page(zbpg); - zcache_evicted_raw_pages++; - if (--nr <= 0) - goto out; - goto retry_unused_list; - } - spin_unlock_bh(&zbpg_unused_list_spinlock); - - /* now try freeing unbuddied pages, starting with least space avail */ - for (i = 0; i < MAX_CHUNK; i++) { -retry_unbud_list_i: - spin_lock_bh(&zbud_budlists_spinlock); - if (list_empty(&zbud_unbuddied[i].list)) { - spin_unlock_bh(&zbud_budlists_spinlock); - continue; - } - list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) { - if (unlikely(!spin_trylock(&zbpg->lock))) - continue; - list_del_init(&zbpg->bud_list); - zbud_unbuddied[i].count--; - spin_unlock(&zbud_budlists_spinlock); - zcache_evicted_unbuddied_pages++; - /* want budlists unlocked when doing zbpg eviction */ - zbud_evict_zbpg(zbpg); - local_bh_enable(); - if (--nr <= 0) - goto out; - goto retry_unbud_list_i; - } - spin_unlock_bh(&zbud_budlists_spinlock); - } - - /* as a last resort, free buddied pages */ -retry_bud_list: - spin_lock_bh(&zbud_budlists_spinlock); - if (list_empty(&zbud_buddied_list)) { - spin_unlock_bh(&zbud_budlists_spinlock); - goto out; - } - list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) { - if (unlikely(!spin_trylock(&zbpg->lock))) - continue; - list_del_init(&zbpg->bud_list); - zcache_zbud_buddied_count--; - spin_unlock(&zbud_budlists_spinlock); - zcache_evicted_buddied_pages++; - /* want budlists unlocked when doing zbpg eviction */ - zbud_evict_zbpg(zbpg); - local_bh_enable(); - if (--nr <= 0) - goto out; - goto retry_bud_list; - } - spin_unlock_bh(&zbud_budlists_spinlock); -out: - return; -} - -static void __init zbud_init(void) -{ - int i; - - INIT_LIST_HEAD(&zbud_buddied_list); - - for (i = 0; i < NCHUNKS; i++) - INIT_LIST_HEAD(&zbud_unbuddied[i].list); -} - -#ifdef CONFIG_SYSFS -/* - * These sysfs routines show a nice distribution of how many zbpg's are - * currently (and have ever been placed) in each unbuddied list. It's fun - * to watch but can probably go away before final merge. - */ -static int zbud_show_unbuddied_list_counts(char *buf) -{ - int i; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) - p += sprintf(p, "%u ", zbud_unbuddied[i].count); - return p - buf; -} - -static int zbud_show_cumul_chunk_counts(char *buf) -{ - unsigned long i, chunks = 0, total_chunks = 0, sum_total_chunks = 0; - unsigned long total_chunks_lte_21 = 0, total_chunks_lte_32 = 0; - unsigned long total_chunks_lte_42 = 0; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) { - p += sprintf(p, "%lu ", zbud_cumul_chunk_counts[i]); - chunks += zbud_cumul_chunk_counts[i]; - total_chunks += zbud_cumul_chunk_counts[i]; - sum_total_chunks += i * zbud_cumul_chunk_counts[i]; - if (i == 21) - total_chunks_lte_21 = total_chunks; - if (i == 32) - total_chunks_lte_32 = total_chunks; - if (i == 42) - total_chunks_lte_42 = total_chunks; - } - p += sprintf(p, "<=21:%lu <=32:%lu <=42:%lu, mean:%lu\n", - total_chunks_lte_21, total_chunks_lte_32, total_chunks_lte_42, - chunks == 0 ? 0 : sum_total_chunks / chunks); - return p - buf; -} -#endif - -/********** - * This "zv" PAM implementation combines the slab-based zsmalloc - * with the crypto compression API to maximize the amount of data that can - * be packed into a physical page. - * - * Zv represents a PAM page with the index and object (plus a "size" value - * necessary for decompression) immediately preceding the compressed data. - */ - -#define ZVH_SENTINEL 0x43214321 - -struct zv_hdr { - uint32_t pool_id; - struct tmem_oid oid; - uint32_t index; - size_t size; - DECL_SENTINEL -}; - -/* rudimentary policy limits */ -/* total number of persistent pages may not exceed this percentage */ -static unsigned int zv_page_count_policy_percent = 75; -/* - * byte count defining poor compression; pages with greater zsize will be - * rejected - */ -static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7; -/* - * byte count defining poor *mean* compression; pages with greater zsize - * will be rejected until sufficient better-compressed pages are accepted - * driving the mean below this threshold - */ -static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5; - -static atomic_t zv_curr_dist_counts[NCHUNKS]; -static atomic_t zv_cumul_dist_counts[NCHUNKS]; - -static unsigned long zv_create(struct zs_pool *pool, uint32_t pool_id, - struct tmem_oid *oid, uint32_t index, - void *cdata, unsigned clen) -{ - struct zv_hdr *zv; - u32 size = clen + sizeof(struct zv_hdr); - int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT; - unsigned long handle = 0; - - BUG_ON(!irqs_disabled()); - BUG_ON(chunks >= NCHUNKS); - handle = zs_malloc(pool, size); - if (!handle) - goto out; - atomic_inc(&zv_curr_dist_counts[chunks]); - atomic_inc(&zv_cumul_dist_counts[chunks]); - zv = zs_map_object(pool, handle, ZS_MM_WO); - zv->index = index; - zv->oid = *oid; - zv->pool_id = pool_id; - zv->size = clen; - SET_SENTINEL(zv, ZVH); - memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen); - zs_unmap_object(pool, handle); -out: - return handle; -} - -static void zv_free(struct zs_pool *pool, unsigned long handle) -{ - unsigned long flags; - struct zv_hdr *zv; - uint16_t size; - int chunks; - - zv = zs_map_object(pool, handle, ZS_MM_RW); - ASSERT_SENTINEL(zv, ZVH); - size = zv->size + sizeof(struct zv_hdr); - INVERT_SENTINEL(zv, ZVH); - zs_unmap_object(pool, handle); - - chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT; - BUG_ON(chunks >= NCHUNKS); - atomic_dec(&zv_curr_dist_counts[chunks]); - - local_irq_save(flags); - zs_free(pool, handle); - local_irq_restore(flags); -} - -static void zv_decompress(struct page *page, unsigned long handle) -{ - unsigned int clen = PAGE_SIZE; - char *to_va; - int ret; - struct zv_hdr *zv; - - zv = zs_map_object(zcache_host.zspool, handle, ZS_MM_RO); - BUG_ON(zv->size == 0); - ASSERT_SENTINEL(zv, ZVH); - to_va = kmap_atomic(page); - ret = zcache_comp_op(ZCACHE_COMPOP_DECOMPRESS, (char *)zv + sizeof(*zv), - zv->size, to_va, &clen); - kunmap_atomic(to_va); - zs_unmap_object(zcache_host.zspool, handle); - BUG_ON(ret); - BUG_ON(clen != PAGE_SIZE); -} - -#ifdef CONFIG_SYSFS -/* - * show a distribution of compression stats for zv pages. - */ - -static int zv_curr_dist_counts_show(char *buf) -{ - unsigned long i, n, chunks = 0, sum_total_chunks = 0; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) { - n = atomic_read(&zv_curr_dist_counts[i]); - p += sprintf(p, "%lu ", n); - chunks += n; - sum_total_chunks += i * n; - } - p += sprintf(p, "mean:%lu\n", - chunks == 0 ? 0 : sum_total_chunks / chunks); - return p - buf; -} - -static int zv_cumul_dist_counts_show(char *buf) -{ - unsigned long i, n, chunks = 0, sum_total_chunks = 0; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) { - n = atomic_read(&zv_cumul_dist_counts[i]); - p += sprintf(p, "%lu ", n); - chunks += n; - sum_total_chunks += i * n; - } - p += sprintf(p, "mean:%lu\n", - chunks == 0 ? 0 : sum_total_chunks / chunks); - return p - buf; -} - -/* - * setting zv_max_zsize via sysfs causes all persistent (e.g. swap) - * pages that don't compress to less than this value (including metadata - * overhead) to be rejected. We don't allow the value to get too close - * to PAGE_SIZE. - */ -static ssize_t zv_max_zsize_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) -{ - return sprintf(buf, "%u\n", zv_max_zsize); -} - -static ssize_t zv_max_zsize_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) -{ - unsigned long val; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - err = kstrtoul(buf, 10, &val); - if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) - return -EINVAL; - zv_max_zsize = val; - return count; -} - -/* - * setting zv_max_mean_zsize via sysfs causes all persistent (e.g. swap) - * pages that don't compress to less than this value (including metadata - * overhead) to be rejected UNLESS the mean compression is also smaller - * than this value. In other words, we are load-balancing-by-zsize the - * accepted pages. Again, we don't allow the value to get too close - * to PAGE_SIZE. - */ -static ssize_t zv_max_mean_zsize_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) -{ - return sprintf(buf, "%u\n", zv_max_mean_zsize); -} - -static ssize_t zv_max_mean_zsize_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) -{ - unsigned long val; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - err = kstrtoul(buf, 10, &val); - if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) - return -EINVAL; - zv_max_mean_zsize = val; - return count; -} - -/* - * setting zv_page_count_policy_percent via sysfs sets an upper bound of - * persistent (e.g. swap) pages that will be retained according to: - * (zv_page_count_policy_percent * totalram_pages) / 100) - * when that limit is reached, further puts will be rejected (until - * some pages have been flushed). Note that, due to compression, - * this number may exceed 100; it defaults to 75 and we set an - * arbitary limit of 150. A poor choice will almost certainly result - * in OOM's, so this value should only be changed prudently. - */ -static ssize_t zv_page_count_policy_percent_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) -{ - return sprintf(buf, "%u\n", zv_page_count_policy_percent); -} - -static ssize_t zv_page_count_policy_percent_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) -{ - unsigned long val; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - err = kstrtoul(buf, 10, &val); - if (err || (val == 0) || (val > 150)) - return -EINVAL; - zv_page_count_policy_percent = val; - return count; -} - -static struct kobj_attribute zcache_zv_max_zsize_attr = { - .attr = { .name = "zv_max_zsize", .mode = 0644 }, - .show = zv_max_zsize_show, - .store = zv_max_zsize_store, -}; - -static struct kobj_attribute zcache_zv_max_mean_zsize_attr = { - .attr = { .name = "zv_max_mean_zsize", .mode = 0644 }, - .show = zv_max_mean_zsize_show, - .store = zv_max_mean_zsize_store, -}; - -static struct kobj_attribute zcache_zv_page_count_policy_percent_attr = { - .attr = { .name = "zv_page_count_policy_percent", - .mode = 0644 }, - .show = zv_page_count_policy_percent_show, - .store = zv_page_count_policy_percent_store, -}; -#endif - -/* - * zcache core code starts here - */ - -/* useful stats not collected by cleancache or frontswap */ -static unsigned long zcache_flush_total; -static unsigned long zcache_flush_found; -static unsigned long zcache_flobj_total; -static unsigned long zcache_flobj_found; -static unsigned long zcache_failed_eph_puts; -static unsigned long zcache_failed_pers_puts; - -/* - * Tmem operations assume the poolid implies the invoking client. - * Zcache only has one client (the kernel itself): LOCAL_CLIENT. - * RAMster has each client numbered by cluster node, and a KVM version - * of zcache would have one client per guest and each client might - * have a poolid==N. - */ -static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid) -{ - struct tmem_pool *pool = NULL; - struct zcache_client *cli = NULL; - - cli = get_zcache_client(cli_id); - if (!cli) - goto out; - - atomic_inc(&cli->refcount); - pool = idr_find(&cli->tmem_pools, poolid); - if (pool != NULL) - atomic_inc(&pool->refcount); -out: - return pool; -} - -static void zcache_put_pool(struct tmem_pool *pool) -{ - struct zcache_client *cli = NULL; - - if (pool == NULL) - BUG(); - cli = pool->client; - atomic_dec(&pool->refcount); - atomic_dec(&cli->refcount); -} - -int zcache_new_client(uint16_t cli_id) -{ - struct zcache_client *cli; - int ret = -1; - - cli = get_zcache_client(cli_id); - - if (cli == NULL) - goto out; - if (cli->allocated) - goto out; - cli->allocated = 1; -#ifdef CONFIG_FRONTSWAP - cli->zspool = zs_create_pool("zcache", ZCACHE_GFP_MASK); - if (cli->zspool == NULL) - goto out; - idr_init(&cli->tmem_pools); -#endif - ret = 0; -out: - return ret; -} - -/* counters for debugging */ -static unsigned long zcache_failed_get_free_pages; -static unsigned long zcache_failed_alloc; -static unsigned long zcache_put_to_flush; - -/* - * for now, used named slabs so can easily track usage; later can - * either just use kmalloc, or perhaps add a slab-like allocator - * to more carefully manage total memory utilization - */ -static struct kmem_cache *zcache_objnode_cache; -static struct kmem_cache *zcache_obj_cache; -static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_obj_count_max; -static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_objnode_count_max; - -/* - * to avoid memory allocation recursion (e.g. due to direct reclaim), we - * preload all necessary data structures so the hostops callbacks never - * actually do a malloc - */ -struct zcache_preload { - void *page; - struct tmem_obj *obj; - int nr; - struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH]; -}; -static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, }; - -static int zcache_do_preload(struct tmem_pool *pool) -{ - struct zcache_preload *kp; - struct tmem_objnode *objnode; - struct tmem_obj *obj; - void *page; - int ret = -ENOMEM; - - if (unlikely(zcache_objnode_cache == NULL)) - goto out; - if (unlikely(zcache_obj_cache == NULL)) - goto out; - - /* IRQ has already been disabled. */ - kp = &__get_cpu_var(zcache_preloads); - while (kp->nr < ARRAY_SIZE(kp->objnodes)) { - objnode = kmem_cache_alloc(zcache_objnode_cache, - ZCACHE_GFP_MASK); - if (unlikely(objnode == NULL)) { - zcache_failed_alloc++; - goto out; - } - - kp->objnodes[kp->nr++] = objnode; - } - - if (!kp->obj) { - obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK); - if (unlikely(obj == NULL)) { - zcache_failed_alloc++; - goto out; - } - kp->obj = obj; - } - - if (!kp->page) { - page = (void *)__get_free_page(ZCACHE_GFP_MASK); - if (unlikely(page == NULL)) { - zcache_failed_get_free_pages++; - goto out; - } - kp->page = page; - } - - ret = 0; -out: - return ret; -} - -static void *zcache_get_free_page(void) -{ - struct zcache_preload *kp; - void *page; - - kp = &__get_cpu_var(zcache_preloads); - page = kp->page; - BUG_ON(page == NULL); - kp->page = NULL; - return page; -} - -static void zcache_free_page(void *p) -{ - free_page((unsigned long)p); -} - -/* - * zcache implementation for tmem host ops - */ - -static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool) -{ - struct tmem_objnode *objnode = NULL; - unsigned long count; - struct zcache_preload *kp; - - kp = &__get_cpu_var(zcache_preloads); - if (kp->nr <= 0) - goto out; - objnode = kp->objnodes[kp->nr - 1]; - BUG_ON(objnode == NULL); - kp->objnodes[kp->nr - 1] = NULL; - kp->nr--; - count = atomic_inc_return(&zcache_curr_objnode_count); - if (count > zcache_curr_objnode_count_max) - zcache_curr_objnode_count_max = count; -out: - return objnode; -} - -static void zcache_objnode_free(struct tmem_objnode *objnode, - struct tmem_pool *pool) -{ - atomic_dec(&zcache_curr_objnode_count); - BUG_ON(atomic_read(&zcache_curr_objnode_count) < 0); - kmem_cache_free(zcache_objnode_cache, objnode); -} - -static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool) -{ - struct tmem_obj *obj = NULL; - unsigned long count; - struct zcache_preload *kp; - - kp = &__get_cpu_var(zcache_preloads); - obj = kp->obj; - BUG_ON(obj == NULL); - kp->obj = NULL; - count = atomic_inc_return(&zcache_curr_obj_count); - if (count > zcache_curr_obj_count_max) - zcache_curr_obj_count_max = count; - return obj; -} - -static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool) -{ - atomic_dec(&zcache_curr_obj_count); - BUG_ON(atomic_read(&zcache_curr_obj_count) < 0); - kmem_cache_free(zcache_obj_cache, obj); -} - -static struct tmem_hostops zcache_hostops = { - .obj_alloc = zcache_obj_alloc, - .obj_free = zcache_obj_free, - .objnode_alloc = zcache_objnode_alloc, - .objnode_free = zcache_objnode_free, -}; - -/* - * zcache implementations for PAM page descriptor ops - */ - -static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_eph_pampd_count_max; -static atomic_t zcache_curr_pers_pampd_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_pers_pampd_count_max; - -/* forward reference */ -static int zcache_compress(struct page *from, void **out_va, unsigned *out_len); - -static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph, - struct tmem_pool *pool, struct tmem_oid *oid, - uint32_t index) -{ - void *pampd = NULL, *cdata; - unsigned clen; - int ret; - unsigned long count; - struct page *page = (struct page *)(data); - struct zcache_client *cli = pool->client; - uint16_t client_id = get_client_id_from_client(cli); - unsigned long zv_mean_zsize; - unsigned long curr_pers_pampd_count; - u64 total_zsize; - - if (eph) { - ret = zcache_compress(page, &cdata, &clen); - if (ret == 0) - goto out; - if (clen == 0 || clen > zbud_max_buddy_size()) { - zcache_compress_poor++; - goto out; - } - pampd = (void *)zbud_create(client_id, pool->pool_id, oid, - index, page, cdata, clen); - if (pampd != NULL) { - count = atomic_inc_return(&zcache_curr_eph_pampd_count); - if (count > zcache_curr_eph_pampd_count_max) - zcache_curr_eph_pampd_count_max = count; - } - } else { - curr_pers_pampd_count = - atomic_read(&zcache_curr_pers_pampd_count); - if (curr_pers_pampd_count > - (zv_page_count_policy_percent * totalram_pages) / 100) - goto out; - ret = zcache_compress(page, &cdata, &clen); - if (ret == 0) - goto out; - /* reject if compression is too poor */ - if (clen > zv_max_zsize) { - zcache_compress_poor++; - goto out; - } - /* reject if mean compression is too poor */ - if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) { - total_zsize = zs_get_total_size_bytes(cli->zspool); - zv_mean_zsize = div_u64(total_zsize, - curr_pers_pampd_count); - if (zv_mean_zsize > zv_max_mean_zsize) { - zcache_mean_compress_poor++; - goto out; - } - } - pampd = (void *)zv_create(cli->zspool, pool->pool_id, - oid, index, cdata, clen); - if (pampd == NULL) - goto out; - count = atomic_inc_return(&zcache_curr_pers_pampd_count); - if (count > zcache_curr_pers_pampd_count_max) - zcache_curr_pers_pampd_count_max = count; - } -out: - return pampd; -} - -/* - * fill the pageframe corresponding to the struct page with the data - * from the passed pampd - */ -static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw, - void *pampd, struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index) -{ - int ret = 0; - - BUG_ON(is_ephemeral(pool)); - zv_decompress((struct page *)(data), (unsigned long)pampd); - return ret; -} - -/* - * fill the pageframe corresponding to the struct page with the data - * from the passed pampd - */ -static int zcache_pampd_get_data_and_free(char *data, size_t *bufsize, bool raw, - void *pampd, struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index) -{ - BUG_ON(!is_ephemeral(pool)); - if (zbud_decompress((struct page *)(data), pampd) < 0) - return -EINVAL; - zbud_free_and_delist((struct zbud_hdr *)pampd); - atomic_dec(&zcache_curr_eph_pampd_count); - return 0; -} - -/* - * free the pampd and remove it from any zcache lists - * pampd must no longer be pointed to from any tmem data structures! - */ -static void zcache_pampd_free(void *pampd, struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index) -{ - struct zcache_client *cli = pool->client; - - if (is_ephemeral(pool)) { - zbud_free_and_delist((struct zbud_hdr *)pampd); - atomic_dec(&zcache_curr_eph_pampd_count); - BUG_ON(atomic_read(&zcache_curr_eph_pampd_count) < 0); - } else { - zv_free(cli->zspool, (unsigned long)pampd); - atomic_dec(&zcache_curr_pers_pampd_count); - BUG_ON(atomic_read(&zcache_curr_pers_pampd_count) < 0); - } -} - -static void zcache_pampd_free_obj(struct tmem_pool *pool, struct tmem_obj *obj) -{ -} - -static void zcache_pampd_new_obj(struct tmem_obj *obj) -{ -} - -static int zcache_pampd_replace_in_obj(void *pampd, struct tmem_obj *obj) -{ - return -1; -} - -static bool zcache_pampd_is_remote(void *pampd) -{ - return 0; -} - -static struct tmem_pamops zcache_pamops = { - .create = zcache_pampd_create, - .get_data = zcache_pampd_get_data, - .get_data_and_free = zcache_pampd_get_data_and_free, - .free = zcache_pampd_free, - .free_obj = zcache_pampd_free_obj, - .new_obj = zcache_pampd_new_obj, - .replace_in_obj = zcache_pampd_replace_in_obj, - .is_remote = zcache_pampd_is_remote, -}; - -/* - * zcache compression/decompression and related per-cpu stuff - */ - -static DEFINE_PER_CPU(unsigned char *, zcache_dstmem); -#define ZCACHE_DSTMEM_ORDER 1 - -static int zcache_compress(struct page *from, void **out_va, unsigned *out_len) -{ - int ret = 0; - unsigned char *dmem = __get_cpu_var(zcache_dstmem); - char *from_va; - - BUG_ON(!irqs_disabled()); - if (unlikely(dmem == NULL)) - goto out; /* no buffer or no compressor so can't compress */ - *out_len = PAGE_SIZE << ZCACHE_DSTMEM_ORDER; - from_va = kmap_atomic(from); - mb(); - ret = zcache_comp_op(ZCACHE_COMPOP_COMPRESS, from_va, PAGE_SIZE, dmem, - out_len); - BUG_ON(ret); - *out_va = dmem; - kunmap_atomic(from_va); - ret = 1; -out: - return ret; -} - -static int zcache_comp_cpu_up(int cpu) -{ - struct crypto_comp *tfm; - - tfm = crypto_alloc_comp(zcache_comp_name, 0, 0); - if (IS_ERR(tfm)) - return NOTIFY_BAD; - *per_cpu_ptr(zcache_comp_pcpu_tfms, cpu) = tfm; - return NOTIFY_OK; -} - -static void zcache_comp_cpu_down(int cpu) -{ - struct crypto_comp *tfm; - - tfm = *per_cpu_ptr(zcache_comp_pcpu_tfms, cpu); - crypto_free_comp(tfm); - *per_cpu_ptr(zcache_comp_pcpu_tfms, cpu) = NULL; -} - -static int zcache_cpu_notifier(struct notifier_block *nb, - unsigned long action, void *pcpu) -{ - int ret, cpu = (long)pcpu; - struct zcache_preload *kp; - - switch (action) { - case CPU_UP_PREPARE: - ret = zcache_comp_cpu_up(cpu); - if (ret != NOTIFY_OK) { - pr_err("zcache: can't allocate compressor transform\n"); - return ret; - } - per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages( - GFP_KERNEL | __GFP_REPEAT, ZCACHE_DSTMEM_ORDER); - break; - case CPU_DEAD: - case CPU_UP_CANCELED: - zcache_comp_cpu_down(cpu); - free_pages((unsigned long)per_cpu(zcache_dstmem, cpu), - ZCACHE_DSTMEM_ORDER); - per_cpu(zcache_dstmem, cpu) = NULL; - kp = &per_cpu(zcache_preloads, cpu); - while (kp->nr) { - kmem_cache_free(zcache_objnode_cache, - kp->objnodes[kp->nr - 1]); - kp->objnodes[kp->nr - 1] = NULL; - kp->nr--; - } - if (kp->obj) { - kmem_cache_free(zcache_obj_cache, kp->obj); - kp->obj = NULL; - } - if (kp->page) { - free_page((unsigned long)kp->page); - kp->page = NULL; - } - break; - default: - break; - } - return NOTIFY_OK; -} - -static struct notifier_block zcache_cpu_notifier_block = { - .notifier_call = zcache_cpu_notifier -}; - -#ifdef CONFIG_SYSFS -#define ZCACHE_SYSFS_RO(_name) \ - static ssize_t zcache_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return sprintf(buf, "%lu\n", zcache_##_name); \ - } \ - static struct kobj_attribute zcache_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = zcache_##_name##_show, \ - } - -#define ZCACHE_SYSFS_RO_ATOMIC(_name) \ - static ssize_t zcache_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return sprintf(buf, "%d\n", atomic_read(&zcache_##_name)); \ - } \ - static struct kobj_attribute zcache_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = zcache_##_name##_show, \ - } - -#define ZCACHE_SYSFS_RO_CUSTOM(_name, _func) \ - static ssize_t zcache_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return _func(buf); \ - } \ - static struct kobj_attribute zcache_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = zcache_##_name##_show, \ - } - -ZCACHE_SYSFS_RO(curr_obj_count_max); -ZCACHE_SYSFS_RO(curr_objnode_count_max); -ZCACHE_SYSFS_RO(flush_total); -ZCACHE_SYSFS_RO(flush_found); -ZCACHE_SYSFS_RO(flobj_total); -ZCACHE_SYSFS_RO(flobj_found); -ZCACHE_SYSFS_RO(failed_eph_puts); -ZCACHE_SYSFS_RO(failed_pers_puts); -ZCACHE_SYSFS_RO(zbud_curr_zbytes); -ZCACHE_SYSFS_RO(zbud_cumul_zpages); -ZCACHE_SYSFS_RO(zbud_cumul_zbytes); -ZCACHE_SYSFS_RO(zbud_buddied_count); -ZCACHE_SYSFS_RO(zbpg_unused_list_count); -ZCACHE_SYSFS_RO(evicted_raw_pages); -ZCACHE_SYSFS_RO(evicted_unbuddied_pages); -ZCACHE_SYSFS_RO(evicted_buddied_pages); -ZCACHE_SYSFS_RO(failed_get_free_pages); -ZCACHE_SYSFS_RO(failed_alloc); -ZCACHE_SYSFS_RO(put_to_flush); -ZCACHE_SYSFS_RO(compress_poor); -ZCACHE_SYSFS_RO(mean_compress_poor); -ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages); -ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages); -ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count); -ZCACHE_SYSFS_RO_ATOMIC(curr_objnode_count); -ZCACHE_SYSFS_RO_CUSTOM(zbud_unbuddied_list_counts, - zbud_show_unbuddied_list_counts); -ZCACHE_SYSFS_RO_CUSTOM(zbud_cumul_chunk_counts, - zbud_show_cumul_chunk_counts); -ZCACHE_SYSFS_RO_CUSTOM(zv_curr_dist_counts, - zv_curr_dist_counts_show); -ZCACHE_SYSFS_RO_CUSTOM(zv_cumul_dist_counts, - zv_cumul_dist_counts_show); - -static struct attribute *zcache_attrs[] = { - &zcache_curr_obj_count_attr.attr, - &zcache_curr_obj_count_max_attr.attr, - &zcache_curr_objnode_count_attr.attr, - &zcache_curr_objnode_count_max_attr.attr, - &zcache_flush_total_attr.attr, - &zcache_flobj_total_attr.attr, - &zcache_flush_found_attr.attr, - &zcache_flobj_found_attr.attr, - &zcache_failed_eph_puts_attr.attr, - &zcache_failed_pers_puts_attr.attr, - &zcache_compress_poor_attr.attr, - &zcache_mean_compress_poor_attr.attr, - &zcache_zbud_curr_raw_pages_attr.attr, - &zcache_zbud_curr_zpages_attr.attr, - &zcache_zbud_curr_zbytes_attr.attr, - &zcache_zbud_cumul_zpages_attr.attr, - &zcache_zbud_cumul_zbytes_attr.attr, - &zcache_zbud_buddied_count_attr.attr, - &zcache_zbpg_unused_list_count_attr.attr, - &zcache_evicted_raw_pages_attr.attr, - &zcache_evicted_unbuddied_pages_attr.attr, - &zcache_evicted_buddied_pages_attr.attr, - &zcache_failed_get_free_pages_attr.attr, - &zcache_failed_alloc_attr.attr, - &zcache_put_to_flush_attr.attr, - &zcache_zbud_unbuddied_list_counts_attr.attr, - &zcache_zbud_cumul_chunk_counts_attr.attr, - &zcache_zv_curr_dist_counts_attr.attr, - &zcache_zv_cumul_dist_counts_attr.attr, - &zcache_zv_max_zsize_attr.attr, - &zcache_zv_max_mean_zsize_attr.attr, - &zcache_zv_page_count_policy_percent_attr.attr, - NULL, -}; - -static struct attribute_group zcache_attr_group = { - .attrs = zcache_attrs, - .name = "zcache", -}; - -#endif /* CONFIG_SYSFS */ -/* - * When zcache is disabled ("frozen"), pools can be created and destroyed, - * but all puts (and thus all other operations that require memory allocation) - * must fail. If zcache is unfrozen, accepts puts, then frozen again, - * data consistency requires all puts while frozen to be converted into - * flushes. - */ -static bool zcache_freeze; - -/* - * zcache shrinker interface (only useful for ephemeral pages, so zbud only) - */ -static int shrink_zcache_memory(struct shrinker *shrink, - struct shrink_control *sc) -{ - int ret = -1; - int nr = sc->nr_to_scan; - gfp_t gfp_mask = sc->gfp_mask; - - if (nr >= 0) { - if (!(gfp_mask & __GFP_FS)) - /* does this case really need to be skipped? */ - goto out; - zbud_evict_pages(nr); - } - ret = (int)atomic_read(&zcache_zbud_curr_raw_pages); -out: - return ret; -} - -static struct shrinker zcache_shrinker = { - .shrink = shrink_zcache_memory, - .seeks = DEFAULT_SEEKS, -}; - -/* - * zcache shims between cleancache/frontswap ops and tmem - */ - -static int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp, - uint32_t index, struct page *page) -{ - struct tmem_pool *pool; - int ret = -1; - - BUG_ON(!irqs_disabled()); - pool = zcache_get_pool_by_id(cli_id, pool_id); - if (unlikely(pool == NULL)) - goto out; - if (!zcache_freeze && zcache_do_preload(pool) == 0) { - /* preload does preempt_disable on success */ - ret = tmem_put(pool, oidp, index, (char *)(page), - PAGE_SIZE, 0, is_ephemeral(pool)); - if (ret < 0) { - if (is_ephemeral(pool)) - zcache_failed_eph_puts++; - else - zcache_failed_pers_puts++; - } - } else { - zcache_put_to_flush++; - if (atomic_read(&pool->obj_count) > 0) - /* the put fails whether the flush succeeds or not */ - (void)tmem_flush_page(pool, oidp, index); - } - - zcache_put_pool(pool); -out: - return ret; -} - -static int zcache_get_page(int cli_id, int pool_id, struct tmem_oid *oidp, - uint32_t index, struct page *page) -{ - struct tmem_pool *pool; - int ret = -1; - unsigned long flags; - size_t size = PAGE_SIZE; - - local_irq_save(flags); - pool = zcache_get_pool_by_id(cli_id, pool_id); - if (likely(pool != NULL)) { - if (atomic_read(&pool->obj_count) > 0) - ret = tmem_get(pool, oidp, index, (char *)(page), - &size, 0, is_ephemeral(pool)); - zcache_put_pool(pool); - } - local_irq_restore(flags); - return ret; -} - -static int zcache_flush_page(int cli_id, int pool_id, - struct tmem_oid *oidp, uint32_t index) -{ - struct tmem_pool *pool; - int ret = -1; - unsigned long flags; - - local_irq_save(flags); - zcache_flush_total++; - pool = zcache_get_pool_by_id(cli_id, pool_id); - if (likely(pool != NULL)) { - if (atomic_read(&pool->obj_count) > 0) - ret = tmem_flush_page(pool, oidp, index); - zcache_put_pool(pool); - } - if (ret >= 0) - zcache_flush_found++; - local_irq_restore(flags); - return ret; -} - -static int zcache_flush_object(int cli_id, int pool_id, - struct tmem_oid *oidp) -{ - struct tmem_pool *pool; - int ret = -1; - unsigned long flags; - - local_irq_save(flags); - zcache_flobj_total++; - pool = zcache_get_pool_by_id(cli_id, pool_id); - if (likely(pool != NULL)) { - if (atomic_read(&pool->obj_count) > 0) - ret = tmem_flush_object(pool, oidp); - zcache_put_pool(pool); - } - if (ret >= 0) - zcache_flobj_found++; - local_irq_restore(flags); - return ret; -} - -static int zcache_destroy_pool(int cli_id, int pool_id) -{ - struct tmem_pool *pool = NULL; - struct zcache_client *cli; - int ret = -1; - - if (pool_id < 0) - goto out; - - cli = get_zcache_client(cli_id); - if (cli == NULL) - goto out; - - atomic_inc(&cli->refcount); - pool = idr_find(&cli->tmem_pools, pool_id); - if (pool == NULL) - goto out; - idr_remove(&cli->tmem_pools, pool_id); - /* wait for pool activity on other cpus to quiesce */ - while (atomic_read(&pool->refcount) != 0) - ; - atomic_dec(&cli->refcount); - local_bh_disable(); - ret = tmem_destroy_pool(pool); - local_bh_enable(); - kfree(pool); - pr_info("zcache: destroyed pool id=%d, cli_id=%d\n", - pool_id, cli_id); -out: - return ret; -} - -static int zcache_new_pool(uint16_t cli_id, uint32_t flags) -{ - int poolid = -1; - struct tmem_pool *pool; - struct zcache_client *cli = NULL; - int r; - - cli = get_zcache_client(cli_id); - if (cli == NULL) - goto out; - - atomic_inc(&cli->refcount); - pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC); - if (pool == NULL) { - pr_info("zcache: pool creation failed: out of memory\n"); - goto out; - } - - do { - r = idr_pre_get(&cli->tmem_pools, GFP_ATOMIC); - if (r != 1) { - kfree(pool); - pr_info("zcache: pool creation failed: out of memory\n"); - goto out; - } - r = idr_get_new(&cli->tmem_pools, pool, &poolid); - } while (r == -EAGAIN); - if (r) { - pr_info("zcache: pool creation failed: error %d\n", r); - kfree(pool); - goto out; - } - - atomic_set(&pool->refcount, 0); - pool->client = cli; - pool->pool_id = poolid; - tmem_new_pool(pool, flags); - pr_info("zcache: created %s tmem pool, id=%d, client=%d\n", - flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", - poolid, cli_id); -out: - if (cli != NULL) - atomic_dec(&cli->refcount); - return poolid; -} - -/********** - * Two kernel functionalities currently can be layered on top of tmem. - * These are "cleancache" which is used as a second-chance cache for clean - * page cache pages; and "frontswap" which is used for swap pages - * to avoid writes to disk. A generic "shim" is provided here for each - * to translate in-kernel semantics to zcache semantics. - */ - -#ifdef CONFIG_CLEANCACHE -static void zcache_cleancache_put_page(int pool_id, - struct cleancache_filekey key, - pgoff_t index, struct page *page) -{ - u32 ind = (u32) index; - struct tmem_oid oid = *(struct tmem_oid *)&key; - - if (likely(ind == index)) - (void)zcache_put_page(LOCAL_CLIENT, pool_id, &oid, index, page); -} - -static int zcache_cleancache_get_page(int pool_id, - struct cleancache_filekey key, - pgoff_t index, struct page *page) -{ - u32 ind = (u32) index; - struct tmem_oid oid = *(struct tmem_oid *)&key; - int ret = -1; - - if (likely(ind == index)) - ret = zcache_get_page(LOCAL_CLIENT, pool_id, &oid, index, page); - return ret; -} - -static void zcache_cleancache_flush_page(int pool_id, - struct cleancache_filekey key, - pgoff_t index) -{ - u32 ind = (u32) index; - struct tmem_oid oid = *(struct tmem_oid *)&key; - - if (likely(ind == index)) - (void)zcache_flush_page(LOCAL_CLIENT, pool_id, &oid, ind); -} - -static void zcache_cleancache_flush_inode(int pool_id, - struct cleancache_filekey key) -{ - struct tmem_oid oid = *(struct tmem_oid *)&key; - - (void)zcache_flush_object(LOCAL_CLIENT, pool_id, &oid); -} - -static void zcache_cleancache_flush_fs(int pool_id) -{ - if (pool_id >= 0) - (void)zcache_destroy_pool(LOCAL_CLIENT, pool_id); -} - -static int zcache_cleancache_init_fs(size_t pagesize) -{ - BUG_ON(sizeof(struct cleancache_filekey) != - sizeof(struct tmem_oid)); - BUG_ON(pagesize != PAGE_SIZE); - return zcache_new_pool(LOCAL_CLIENT, 0); -} - -static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) -{ - /* shared pools are unsupported and map to private */ - BUG_ON(sizeof(struct cleancache_filekey) != - sizeof(struct tmem_oid)); - BUG_ON(pagesize != PAGE_SIZE); - return zcache_new_pool(LOCAL_CLIENT, 0); -} - -static struct cleancache_ops zcache_cleancache_ops = { - .put_page = zcache_cleancache_put_page, - .get_page = zcache_cleancache_get_page, - .invalidate_page = zcache_cleancache_flush_page, - .invalidate_inode = zcache_cleancache_flush_inode, - .invalidate_fs = zcache_cleancache_flush_fs, - .init_shared_fs = zcache_cleancache_init_shared_fs, - .init_fs = zcache_cleancache_init_fs -}; - -struct cleancache_ops zcache_cleancache_register_ops(void) -{ - struct cleancache_ops old_ops = - cleancache_register_ops(&zcache_cleancache_ops); - - return old_ops; -} -#endif - -#ifdef CONFIG_FRONTSWAP -/* a single tmem poolid is used for all frontswap "types" (swapfiles) */ -static int zcache_frontswap_poolid = -1; - -/* - * Swizzling increases objects per swaptype, increasing tmem concurrency - * for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS - * Setting SWIZ_BITS to 27 basically reconstructs the swap entry from - * frontswap_load(), but has side-effects. Hence using 8. - */ -#define SWIZ_BITS 8 -#define SWIZ_MASK ((1 << SWIZ_BITS) - 1) -#define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK)) -#define iswiz(_ind) (_ind >> SWIZ_BITS) - -static inline struct tmem_oid oswiz(unsigned type, u32 ind) -{ - struct tmem_oid oid = { .oid = { 0 } }; - oid.oid[0] = _oswiz(type, ind); - return oid; -} - -static int zcache_frontswap_store(unsigned type, pgoff_t offset, - struct page *page) -{ - u64 ind64 = (u64)offset; - u32 ind = (u32)offset; - struct tmem_oid oid = oswiz(type, ind); - int ret = -1; - unsigned long flags; - - BUG_ON(!PageLocked(page)); - if (likely(ind64 == ind)) { - local_irq_save(flags); - ret = zcache_put_page(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind), page); - local_irq_restore(flags); - } - return ret; -} - -/* returns 0 if the page was successfully gotten from frontswap, -1 if - * was not present (should never happen!) */ -static int zcache_frontswap_load(unsigned type, pgoff_t offset, - struct page *page) -{ - u64 ind64 = (u64)offset; - u32 ind = (u32)offset; - struct tmem_oid oid = oswiz(type, ind); - int ret = -1; - - BUG_ON(!PageLocked(page)); - if (likely(ind64 == ind)) - ret = zcache_get_page(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind), page); - return ret; -} - -/* flush a single page from frontswap */ -static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset) -{ - u64 ind64 = (u64)offset; - u32 ind = (u32)offset; - struct tmem_oid oid = oswiz(type, ind); - - if (likely(ind64 == ind)) - (void)zcache_flush_page(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind)); -} - -/* flush all pages from the passed swaptype */ -static void zcache_frontswap_flush_area(unsigned type) -{ - struct tmem_oid oid; - int ind; - - for (ind = SWIZ_MASK; ind >= 0; ind--) { - oid = oswiz(type, ind); - (void)zcache_flush_object(LOCAL_CLIENT, - zcache_frontswap_poolid, &oid); - } -} - -static void zcache_frontswap_init(unsigned ignored) -{ - /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ - if (zcache_frontswap_poolid < 0) - zcache_frontswap_poolid = - zcache_new_pool(LOCAL_CLIENT, TMEM_POOL_PERSIST); -} - -static struct frontswap_ops zcache_frontswap_ops = { - .store = zcache_frontswap_store, - .load = zcache_frontswap_load, - .invalidate_page = zcache_frontswap_flush_page, - .invalidate_area = zcache_frontswap_flush_area, - .init = zcache_frontswap_init -}; - -struct frontswap_ops zcache_frontswap_register_ops(void) -{ - struct frontswap_ops old_ops = - frontswap_register_ops(&zcache_frontswap_ops); - - return old_ops; -} -#endif - -/* - * zcache initialization - * NOTE FOR NOW zcache MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR - * NOTHING HAPPENS! - */ - -static int zcache_enabled; - -static int __init enable_zcache(char *s) -{ - zcache_enabled = 1; - return 1; -} -__setup("zcache", enable_zcache); - -/* allow independent dynamic disabling of cleancache and frontswap */ - -static int use_cleancache = 1; - -static int __init no_cleancache(char *s) -{ - use_cleancache = 0; - return 1; -} - -__setup("nocleancache", no_cleancache); - -static int use_frontswap = 1; - -static int __init no_frontswap(char *s) -{ - use_frontswap = 0; - return 1; -} - -__setup("nofrontswap", no_frontswap); - -static int __init enable_zcache_compressor(char *s) -{ - strncpy(zcache_comp_name, s, ZCACHE_COMP_NAME_SZ); - zcache_enabled = 1; - return 1; -} -__setup("zcache=", enable_zcache_compressor); - - -static int __init zcache_comp_init(void) -{ - int ret = 0; - - /* check crypto algorithm */ - if (*zcache_comp_name != '\0') { - ret = crypto_has_comp(zcache_comp_name, 0, 0); - if (!ret) - pr_info("zcache: %s not supported\n", - zcache_comp_name); - } - if (!ret) - strcpy(zcache_comp_name, "lzo"); - ret = crypto_has_comp(zcache_comp_name, 0, 0); - if (!ret) { - ret = 1; - goto out; - } - pr_info("zcache: using %s compressor\n", zcache_comp_name); - - /* alloc percpu transforms */ - ret = 0; - zcache_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *); - if (!zcache_comp_pcpu_tfms) - ret = 1; -out: - return ret; -} - -static int __init zcache_init(void) -{ - int ret = 0; - -#ifdef CONFIG_SYSFS - ret = sysfs_create_group(mm_kobj, &zcache_attr_group); - if (ret) { - pr_err("zcache: can't create sysfs\n"); - goto out; - } -#endif /* CONFIG_SYSFS */ - - if (zcache_enabled) { - unsigned int cpu; - - tmem_register_hostops(&zcache_hostops); - tmem_register_pamops(&zcache_pamops); - ret = register_cpu_notifier(&zcache_cpu_notifier_block); - if (ret) { - pr_err("zcache: can't register cpu notifier\n"); - goto out; - } - ret = zcache_comp_init(); - if (ret) { - pr_err("zcache: compressor initialization failed\n"); - goto out; - } - for_each_online_cpu(cpu) { - void *pcpu = (void *)(long)cpu; - zcache_cpu_notifier(&zcache_cpu_notifier_block, - CPU_UP_PREPARE, pcpu); - } - } - zcache_objnode_cache = kmem_cache_create("zcache_objnode", - sizeof(struct tmem_objnode), 0, 0, NULL); - zcache_obj_cache = kmem_cache_create("zcache_obj", - sizeof(struct tmem_obj), 0, 0, NULL); - ret = zcache_new_client(LOCAL_CLIENT); - if (ret) { - pr_err("zcache: can't create client\n"); - goto out; - } - -#ifdef CONFIG_CLEANCACHE - if (zcache_enabled && use_cleancache) { - struct cleancache_ops old_ops; - - zbud_init(); - register_shrinker(&zcache_shrinker); - old_ops = zcache_cleancache_register_ops(); - pr_info("zcache: cleancache enabled using kernel " - "transcendent memory and compression buddies\n"); - if (old_ops.init_fs != NULL) - pr_warning("zcache: cleancache_ops overridden"); - } -#endif -#ifdef CONFIG_FRONTSWAP - if (zcache_enabled && use_frontswap) { - struct frontswap_ops old_ops; - - old_ops = zcache_frontswap_register_ops(); - pr_info("zcache: frontswap enabled using kernel " - "transcendent memory and zsmalloc\n"); - if (old_ops.init != NULL) - pr_warning("zcache: frontswap_ops overridden"); - } -#endif -out: - return ret; -} - -module_init(zcache_init) |