mm/zsmalloc: use zpdesc in trylock_zspage()/lock_zspage()

Convert trylock_zspage() and lock_zspage() to use zpdesc. To achieve
that, introduce a couple of helper functions:
  - zpdesc_lock()
  - zpdesc_unlock()
  - zpdesc_trylock()
  - zpdesc_wait_locked()
  - zpdesc_get()
  - zpdesc_put()

Here we use the folio version of functions for 2 reasons.  First,
zswap.zpool currently only uses order-0 pages and using folio could save
some compound_head checks.  Second, folio_put could bypass devmap checking
that we don't need.

BTW, thanks Intel LKP found a build warning on the patch.

Originally-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Link: https://lkml.kernel.org/r/20241216150450.1228021-3-42.hyeyoo@gmail.com
Signed-off-by: Alex Shi <alexs@kernel.org>
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/mm/zpdesc.h b/mm/zpdesc.h
index ad0443a1eda4..7c8bea3859f0 100644
--- a/mm/zpdesc.h
+++ b/mm/zpdesc.h
@@ -104,4 +104,34 @@ static_assert(sizeof(struct zpdesc) <= sizeof(struct page));
 	const struct page *:		(const struct zpdesc *)(p),	\
 	struct page *:			(struct zpdesc *)(p)))
 
+static inline void zpdesc_lock(struct zpdesc *zpdesc)
+{
+	folio_lock(zpdesc_folio(zpdesc));
+}
+
+static inline bool zpdesc_trylock(struct zpdesc *zpdesc)
+{
+	return folio_trylock(zpdesc_folio(zpdesc));
+}
+
+static inline void zpdesc_unlock(struct zpdesc *zpdesc)
+{
+	folio_unlock(zpdesc_folio(zpdesc));
+}
+
+static inline void zpdesc_wait_locked(struct zpdesc *zpdesc)
+{
+	folio_wait_locked(zpdesc_folio(zpdesc));
+}
+
+static inline void zpdesc_get(struct zpdesc *zpdesc)
+{
+	folio_get(zpdesc_folio(zpdesc));
+}
+
+static inline void zpdesc_put(struct zpdesc *zpdesc)
+{
+	folio_put(zpdesc_folio(zpdesc));
+}
+
 #endif