f2fs: do not issue next dnode discard redundantly

We have a discard map, so that we can avoid redundant discard issues.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 2c40ce13289563ee84117aa9603564f7890ae5c4..342e0f761d8f717bec40fbb332e0013363a2a94d 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -486,7 +486,20 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 
 void discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
 {
-       if (f2fs_issue_discard(sbi, blkaddr, 1)) {
+       int err = -ENOTSUPP;
+
+       if (test_opt(sbi, DISCARD)) {
+               struct seg_entry *se = get_seg_entry(sbi,
+                               GET_SEGNO(sbi, blkaddr));
+               unsigned int offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
+
+               if (f2fs_test_bit(offset, se->discard_map))
+                       return;
+
+               err = f2fs_issue_discard(sbi, blkaddr, 1);
+       }
+
+       if (err) {
                struct page *page = grab_meta_page(sbi, blkaddr);
                /* zero-filled page */
                set_page_dirty(page);