[PATCH v2 6/7] swap: Add __swap_entry_free_locked()

[Huang, Ying]

The part of __swap_entry_free() with lock held is separated into a new
function __swap_entry_free_locked().  Because we want to reuse that
piece of code in some other places.

Just mechanical code refactoring, there is no any functional change in
this function.

Signed-off-by: "Huang, Ying" <ying.hu...@intel.com>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Michal Hocko <mho...@suse.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: Shaohua Li <s...@kernel.org>
Cc: Hugh Dickins <hu...@google.com>
Cc: Minchan Kim <minc...@kernel.org>
Cc: Rik van Riel <r...@redhat.com>
Cc: Daniel Jordan <daniel.m.jor...@oracle.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
---
 mm/swapfile.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 622edc47b67a..fec28f6c05b0 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1180,16 +1180,13 @@ struct swap_info_struct *get_swap_device(swp_entry_t 
entry)
        return NULL;
 }
 
-static unsigned char __swap_entry_free(struct swap_info_struct *p,
-                                      swp_entry_t entry, unsigned char usage)
+static unsigned char __swap_entry_free_locked(struct swap_info_struct *p,
+                                             unsigned long offset,
+                                             unsigned char usage)
 {
-       struct swap_cluster_info *ci;
-       unsigned long offset = swp_offset(entry);
        unsigned char count;
        unsigned char has_cache;
 
-       ci = lock_cluster_or_swap_info(p, offset);
-
        count = p->swap_map[offset];
 
        has_cache = count & SWAP_HAS_CACHE;
@@ -1217,6 +1214,17 @@ static unsigned char __swap_entry_free(struct 
swap_info_struct *p,
        usage = count | has_cache;
        p->swap_map[offset] = usage ? : SWAP_HAS_CACHE;
 
+       return usage;
+}
+
+static unsigned char __swap_entry_free(struct swap_info_struct *p,
+                                      swp_entry_t entry, unsigned char usage)
+{
+       struct swap_cluster_info *ci;
+       unsigned long offset = swp_offset(entry);
+
+       ci = lock_cluster_or_swap_info(p, offset);
+       usage = __swap_entry_free_locked(p, offset, usage);
        unlock_cluster_or_swap_info(p, ci);
 
        return usage;
-- 
2.16.4