f2fs: send discard commands in larger extent

If there is a chance to make a huge sized discard command, we don't need
to split it out, since each blkdev_issue_discard should wait one at a
time.

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

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 06dda73..2fb3d7f 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -469,10 +469,33 @@ void discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
        }
 }
 
-static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+static void __add_discard_entry(struct f2fs_sb_info *sbi,
+               struct cp_control *cpc, unsigned int start, unsigned int end)
 {
        struct list_head *head = &SM_I(sbi)->discard_list;
-       struct discard_entry *new;
+       struct discard_entry *new, *last;
+
+       if (!list_empty(head)) {
+               last = list_last_entry(head, struct discard_entry, list);
+               if (START_BLOCK(sbi, cpc->trim_start) + start ==
+                                               last->blkaddr + last->len) {
+                       last->len += end - start;
+                       goto done;
+               }
+       }
+
+       new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
+       INIT_LIST_HEAD(&new->list);
+       new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start;
+       new->len = end - start;
+       list_add_tail(&new->list, head);
+done:
+       SM_I(sbi)->nr_discards += end - start;
+       cpc->trimmed += end - start;
+}
+
+static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
+{
        int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
        int max_blocks = sbi->blocks_per_seg;
        struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
@@ -501,13 +524,7 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
                }
                mutex_unlock(&dirty_i->seglist_lock);
 
-               new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
-               INIT_LIST_HEAD(&new->list);
-               new->blkaddr = START_BLOCK(sbi, cpc->trim_start);
-               new->len = sbi->blocks_per_seg;
-               list_add_tail(&new->list, head);
-               SM_I(sbi)->nr_discards += sbi->blocks_per_seg;
-               cpc->trimmed += sbi->blocks_per_seg;
+               __add_discard_entry(sbi, cpc, 0, sbi->blocks_per_seg);
                return;
        }
 
@@ -529,14 +546,7 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc)
                if (end - start < cpc->trim_minlen)
                        continue;
 
-               new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
-               INIT_LIST_HEAD(&new->list);
-               new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start;
-               new->len = end - start;
-               cpc->trimmed += end - start;
-
-               list_add_tail(&new->list, head);
-               SM_I(sbi)->nr_discards += end - start;
+               __add_discard_entry(sbi, cpc, start, end);
        }
 }