frontswap: remove frontswap_tmem_exclusive_gets

frontswap_tmem_exclusive_gets is never called, so remove it.

Link: https://lkml.kernel.org/r/20211224062246.1258487-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: Christoph Hellwig

include/linux/frontswap.h

@@ -26,8 +26,6 @@ struct frontswap_ops {
 extern void frontswap_register_ops(struct frontswap_ops *ops);
 extern void frontswap_shrink(unsigned long);
 extern unsigned long frontswap_curr_pages(void);
-#define FRONTSWAP_HAS_EXCLUSIVE_GETS
-extern void frontswap_tmem_exclusive_gets(bool);
 
 extern bool __frontswap_test(struct swap_info_struct *, pgoff_t);
 extern void __frontswap_init(unsigned type, unsigned long *map);

mm/frontswap.c

@@ -32,13 +32,6 @@ static struct frontswap_ops *frontswap_ops __read_mostly;
 #define for_each_frontswap_ops(ops)		\
 	for ((ops) = frontswap_ops; (ops); (ops) = (ops)->next)
 
-/*
- * If enabled, the underlying tmem implementation is capable of doing
- * exclusive gets, so frontswap_load, on a successful tmem_get must
- * mark the page as no longer in frontswap AND mark it dirty.
- */
-static bool frontswap_tmem_exclusive_gets_enabled __read_mostly;
-
 #ifdef CONFIG_DEBUG_FS
 /*
  * Counters available via /sys/kernel/debug/frontswap (if debugfs is
@@ -160,15 +153,6 @@ void frontswap_register_ops(struct frontswap_ops *ops)
 }
 EXPORT_SYMBOL(frontswap_register_ops);
 
-/*
- * Enable/disable frontswap exclusive gets (see above).
- */
-void frontswap_tmem_exclusive_gets(bool enable)
-{
-	frontswap_tmem_exclusive_gets_enabled = enable;
-}
-EXPORT_SYMBOL(frontswap_tmem_exclusive_gets);
-
 /*
  * Called when a swap device is swapon'd.
  */
@@ -296,13 +280,8 @@ int __frontswap_load(struct page *page)
 		if (!ret) /* successful load */
 			break;
 	}
-	if (ret == 0) {
+	if (ret == 0)
 		inc_frontswap_loads();
-		if (frontswap_tmem_exclusive_gets_enabled) {
-			SetPageDirty(page);
-			__frontswap_clear(sis, offset);
-		}
-	}
 	return ret;
 }
 EXPORT_SYMBOL(__frontswap_load);