[PATCH -V3 3/5] swap: remove __swp_swapcount()

Huang Ying
2023-05-29T06:14:37Z

__swp_swapcount() just encloses the calling to swap_swapcount() with
get/put_swap_device(). It is called in __read_swap_cache_async()
only, which encloses the calling with get/put_swap_device() already.
So, __read_swap_cache_async() can call swap_swapcount() directly.

Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
---
include/linux/swap.h | 4 ++--
mm/swap_state.c | 2 +-
mm/swapfile.c | 20 +-------------------
3 files changed, 4 insertions(+), 22 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 3c69cb653cb9..f6bd51aa05ea 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -512,7 +512,7 @@ int find_first_swap(dev_t *device);
extern unsigned int count_swap_pages(int, int);
extern sector_t swapdev_block(int, pgoff_t);
extern int __swap_count(swp_entry_t entry);
-extern int __swp_swapcount(swp_entry_t entry);
+extern int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry);
extern int swp_swapcount(swp_entry_t entry);
extern struct swap_info_struct *page_swap_info(struct page *);
extern struct swap_info_struct *swp_swap_info(swp_entry_t entry);
@@ -590,7 +590,7 @@ static inline int __swap_count(swp_entry_t entry)
return 0;
}

-static inline int __swp_swapcount(swp_entry_t entry)
+static inline int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry)
{
return 0;
}
diff --git a/mm/swap_state.c b/mm/swap_state.c
index a8450b4a110c..ef32353c18a6 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -447,7 +447,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
* as SWAP_HAS_CACHE. That's done in later part of code or
* else swap_off will be aborted if we return NULL.
*/
- if (!__swp_swapcount(entry) && swap_slot_cache_enabled)
+ if (!swap_swapcount(si, entry) && swap_slot_cache_enabled)
goto fail_put_swap;

/*
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 8419cba9c192..e9cce775fb25 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1443,7 +1443,7 @@ int __swap_count(swp_entry_t entry)
* This does not give an exact answer when swap count is continued,
* but does include the high COUNT_CONTINUED flag to allow for that.
*/
-static int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry)
+int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry)
{
pgoff_t offset = swp_offset(entry);
struct swap_cluster_info *ci;
@@ -1455,24 +1455,6 @@ static int swap_swapcount(struct swap_info_struct *si, swp_entry_t entry)
return count;
}

-/*
- * How many references to @entry are currently swapped out?
- * This does not give an exact answer when swap count is continued,
- * but does include the high COUNT_CONTINUED flag to allow for that.
- */
-int __swp_swapcount(swp_entry_t entry)
-{
- int count = 0;
- struct swap_info_struct *si;
-
- si = get_swap_device(entry);
- if (si) {
- count = swap_swapcount(si, entry);
- put_swap_device(si);
- }
- return count;
-}
-
/*
* How many references to @entry are currently swapped out?
* This considers COUNT_CONTINUED so it returns exact answer.
--
2.39.2