f2fs: decrease the lock granularity during write_begin
This patch reduces the lock granularity during write_begin.
When the system is under memory pressure, it would be better to reduce
the locking time for the data pages.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 6f1a9e2..2d9a46e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -916,6 +916,10 @@
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
+
+ /* to avoid latency during memory pressure */
+ unlock_page(page);
+
*pagep = page;
if (f2fs_has_inline_data(inode) && (pos + len) <= MAX_INLINE_DATA)
@@ -927,10 +931,18 @@
f2fs_unlock_op(sbi);
if (err) {
- f2fs_put_page(page, 1);
+ f2fs_put_page(page, 0);
return err;
}
inline_data:
+ lock_page(page);
+ if (unlikely(page->mapping != mapping)) {
+ f2fs_put_page(page, 1);
+ goto repeat;
+ }
+
+ f2fs_wait_on_page_writeback(page, DATA);
+
if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
return 0;