zpool: clean out dead code

There is a lot of provision for flexibility that isn't actually needed or
used.  Zswap (the only zpool user) always passes zpool_ops with an .evict
method set.  The backends who reclaim only do so for zswap, so they can
also directly call zpool_ops without indirection or checks.

Finally, there is no need to check the retries parameters and bail with
-EINVAL in the reclaim function, when that's called just a few lines below
with a hard-coded 8.  There is no need to duplicate the evictable and
sleep_mapped attrs from the driver in zpool_ops.

Link: https://lkml.kernel.org/r/20221128191616.1261026-3-nphamcs@gmail.com
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 2 insertions, 8 deletions

diff --git a/mm/zpool.c b/mm/zpool.c
index f46c0d5e766c..571f5c5031dd 100644
--- a/mm/zpool.c
+++ b/mm/zpool.c
@@ -21,9 +21,6 @@
 struct zpool {
 	struct zpool_driver *driver;
 	void *pool;
-	const struct zpool_ops *ops;
-	bool evictable;
-	bool can_sleep_mapped;
 };
 
 static LIST_HEAD(drivers_head);
@@ -177,9 +174,6 @@ struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp,
 
 	zpool->driver = driver;
 	zpool->pool = driver->create(name, gfp, ops, zpool);
-	zpool->ops = ops;
-	zpool->evictable = driver->shrink && ops && ops->evict;
-	zpool->can_sleep_mapped = driver->sleep_mapped;
 
 	if (!zpool->pool) {
 		pr_err("couldn't create %s pool\n", type);
@@ -380,7 +374,7 @@ u64 zpool_get_total_size(struct zpool *zpool)
  */
 bool zpool_evictable(struct zpool *zpool)
 {
-	return zpool->evictable;
+	return zpool->driver->shrink;
 }
 
 /**
@@ -398,7 +392,7 @@ bool zpool_evictable(struct zpool *zpool)
  */
 bool zpool_can_sleep_mapped(struct zpool *zpool)
 {
-	return zpool->can_sleep_mapped;
+	return zpool->driver->sleep_mapped;
 }
 
 MODULE_LICENSE("GPL");