zpool: remove zpool_evict()

Remove zpool_evict() helper function.  As zbud is currently the only
zpool implementation that supports eviction, add zpool and zpool_ops
references to struct zbud_pool and directly call zpool_ops->evict(zpool,
handle) on eviction.

Currently zpool provides the zpool_evict helper which locks the zpool
list lock and searches through all pools to find the specific one
matching the caller, and call the corresponding zpool_ops->evict
function.  However, this is unnecessary, as the zbud pool can simply
keep a reference to the zpool that created it, as well as the zpool_ops,
and directly call the zpool_ops->evict function, when it needs to evict
a page.  This avoids a spinlock and list search in zpool for each
eviction.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 28 deletions

diff --git a/mm/zpool.c b/mm/zpool.c
index 6b1f1035cd99..722a4f60e90b 100644
--- a/mm/zpool.c
+++ b/mm/zpool.c
@@ -73,33 +73,6 @@ int zpool_unregister_driver(struct zpool_driver *driver)
 }
 EXPORT_SYMBOL(zpool_unregister_driver);
 
-/**
- * zpool_evict() - evict callback from a zpool implementation.
- * @pool:       pool to evict from.
- * @handle:     handle to evict.
- *
- * This can be used by zpool implementations to call the
- * user's evict zpool_ops struct evict callback.
- */
-int zpool_evict(void *pool, unsigned long handle)
-{
-        struct zpool *zpool;
-
-        spin_lock(&pools_lock);
-        list_for_each_entry(zpool, &pools_head, list) {
-                if (zpool->pool == pool) {
-                        spin_unlock(&pools_lock);
-                        if (!zpool->ops || !zpool->ops->evict)
-                                return -EINVAL;
-                        return zpool->ops->evict(zpool, handle);
-                }
-        }
-        spin_unlock(&pools_lock);
-
-        return -ENOENT;
-}
-EXPORT_SYMBOL(zpool_evict);
-
 static struct zpool_driver *zpool_get_driver(char *type)
 {
         struct zpool_driver *driver;
@@ -170,7 +143,7 @@ struct zpool *zpool_create_pool(char *type, char *name, gfp_t gfp,
 
         zpool->type = driver->type;
         zpool->driver = driver;
-        zpool->pool = driver->create(name, gfp, ops);
+        zpool->pool = driver->create(name, gfp, ops, zpool);
         zpool->ops = ops;
 
         if (!zpool->pool) {