f2fs_bug_on(sbi, prefree_segments(sbi));
                flush_sit_entries(sbi, cpc);
                clear_prefree_segments(sbi, cpc);
-               f2fs_wait_all_discard_bio(sbi);
                unblock_operations(sbi);
                goto out;
        }
 
        /* unlock all the fs_lock[] in do_checkpoint() */
        err = do_checkpoint(sbi, cpc);
-       if (err) {
+       if (err)
                release_discard_addrs(sbi);
-       } else {
+       else
                clear_prefree_segments(sbi, cpc);
-               f2fs_wait_all_discard_bio(sbi);
-       }
 
        unblock_operations(sbi);
        stat_inc_cp_count(sbi->stat_info);
 
 
 struct bio_entry {
        struct list_head list;
+       block_t lstart;
+       block_t len;
        struct bio *bio;
        struct completion event;
        int error;
 void invalidate_blocks(struct f2fs_sb_info *, block_t);
 bool is_checkpointed_data(struct f2fs_sb_info *, block_t);
 void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
-void f2fs_wait_all_discard_bio(struct f2fs_sb_info *);
+void f2fs_wait_discard_bio(struct f2fs_sb_info *, block_t);
 void clear_prefree_segments(struct f2fs_sb_info *, struct cp_control *);
 void release_discard_addrs(struct f2fs_sb_info *);
 int npages_for_summary_flush(struct f2fs_sb_info *, bool);
 
 }
 
 static struct bio_entry *__add_bio_entry(struct f2fs_sb_info *sbi,
-                                                       struct bio *bio)
+                       struct bio *bio, block_t lstart, block_t len)
 {
        struct list_head *wait_list = &(SM_I(sbi)->wait_list);
        struct bio_entry *be = f2fs_kmem_cache_alloc(bio_entry_slab, GFP_NOFS);
 
        INIT_LIST_HEAD(&be->list);
        be->bio = bio;
+       be->lstart = lstart;
+       be->len = len;
        init_completion(&be->event);
        list_add_tail(&be->list, wait_list);
 
        return be;
 }
 
-void f2fs_wait_all_discard_bio(struct f2fs_sb_info *sbi)
+/* This should be covered by global mutex, &sit_i->sentry_lock */
+void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
 {
        struct list_head *wait_list = &(SM_I(sbi)->wait_list);
        struct bio_entry *be, *tmp;
                struct bio *bio = be->bio;
                int err;
 
-               wait_for_completion_io(&be->event);
+               if (!completion_done(&be->event)) {
+                       if ((be->lstart <= blkaddr &&
+                                       blkaddr < be->lstart + be->len) ||
+                                       blkaddr == NULL_ADDR)
+                               wait_for_completion_io(&be->event);
+                       else
+                               continue;
+               }
+
                err = be->error;
                if (err == -EOPNOTSUPP)
                        err = 0;
                struct block_device *bdev, block_t blkstart, block_t blklen)
 {
        struct bio *bio = NULL;
+       block_t lblkstart = blkstart;
        int err;
 
        trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
                                SECTOR_FROM_BLOCK(blklen),
                                GFP_NOFS, 0, &bio);
        if (!err && bio) {
-               struct bio_entry *be = __add_bio_entry(sbi, bio);
+               struct bio_entry *be = __add_bio_entry(sbi, bio,
+                                               lblkstart, blklen);
 
                bio->bi_private = be;
                bio->bi_end_io = f2fs_submit_bio_wait_endio;
                bio->bi_opf |= REQ_SYNC;
                submit_bio(bio);
        }
-
        return err;
 }
 
 
        *new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
 
+       f2fs_wait_discard_bio(sbi, *new_blkaddr);
+
        /*
         * __add_sum_entry should be resided under the curseg_mutex
         * because, this function updates a summary entry in the