mm/swapfile: use list_{prev,next}_entry() instead of open-coding

Use list_{prev,next}_entry() instead of list_entry() for better
code readability.

Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Baoquan He <bhe@redhat.com>
Link: http://lkml.kernel.org/r/1586599916-15456-2-git-send-email-qiwuchen55@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 5871a2a..8d8dc67 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3654,7 +3654,7 @@ static bool swap_count_continued(struct swap_info_struct *si,
 
        spin_lock(&si->cont_lock);
        offset &= ~PAGE_MASK;
-       page = list_entry(head->lru.next, struct page, lru);
+       page = list_next_entry(head, lru);
        map = kmap_atomic(page) + offset;
 
        if (count == SWAP_MAP_MAX)      /* initial increment from swap_map */
@@ -3666,13 +3666,13 @@ static bool swap_count_continued(struct swap_info_struct *si,
                 */
                while (*map == (SWAP_CONT_MAX | COUNT_CONTINUED)) {
                        kunmap_atomic(map);
-                       page = list_entry(page->lru.next, struct page, lru);
+                       page = list_next_entry(page, lru);
                        BUG_ON(page == head);
                        map = kmap_atomic(page) + offset;
                }
                if (*map == SWAP_CONT_MAX) {
                        kunmap_atomic(map);
-                       page = list_entry(page->lru.next, struct page, lru);
+                       page = list_next_entry(page, lru);
                        if (page == head) {
                                ret = false;    /* add count continuation */
                                goto out;
@@ -3682,12 +3682,10 @@ init_map:               *map = 0;               /* we didn't zero the page */
                }
                *map += 1;
                kunmap_atomic(map);
-               page = list_entry(page->lru.prev, struct page, lru);
-               while (page != head) {
+               while ((page = list_prev_entry(page, lru)) != head) {
                        map = kmap_atomic(page) + offset;
                        *map = COUNT_CONTINUED;
                        kunmap_atomic(map);
-                       page = list_entry(page->lru.prev, struct page, lru);
                }
                ret = true;                     /* incremented */
 
@@ -3698,7 +3696,7 @@ init_map:         *map = 0;               /* we didn't zero the page */
                BUG_ON(count != COUNT_CONTINUED);
                while (*map == COUNT_CONTINUED) {
                        kunmap_atomic(map);
-                       page = list_entry(page->lru.next, struct page, lru);
+                       page = list_next_entry(page, lru);
                        BUG_ON(page == head);
                        map = kmap_atomic(page) + offset;
                }
@@ -3707,13 +3705,11 @@ init_map:               *map = 0;               /* we didn't zero the page */
                if (*map == 0)
                        count = 0;
                kunmap_atomic(map);
-               page = list_entry(page->lru.prev, struct page, lru);
-               while (page != head) {
+               while ((page = list_prev_entry(page, lru)) != head) {
                        map = kmap_atomic(page) + offset;
                        *map = SWAP_CONT_MAX | count;
                        count = COUNT_CONTINUED;
                        kunmap_atomic(map);
-                       page = list_entry(page->lru.prev, struct page, lru);
                }
                ret = count == COUNT_CONTINUED;
        }