1 files changed, 85 insertions, 2 deletions

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index d0f74eb..93c5e26 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -26,6 +26,7 @@
 #define __reverse_ffz(x) __reverse_ffs(~(x))
 
 static struct kmem_cache *discard_entry_slab;
+static struct kmem_cache *bio_entry_slab;
 static struct kmem_cache *sit_entry_set_slab;
 static struct kmem_cache *inmem_entry_slab;
 
@@ -580,6 +581,74 @@ static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
 	mutex_unlock(&dirty_i->seglist_lock);
 }
 
+static struct bio_entry *__add_bio_entry(struct f2fs_sb_info *sbi,
+							struct bio *bio)
+{
+	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;
+	init_completion(&be->event);
+	list_add_tail(&be->list, wait_list);
+
+	return be;
+}
+
+void f2fs_wait_all_discard_bio(struct f2fs_sb_info *sbi)
+{
+	struct list_head *wait_list = &(SM_I(sbi)->wait_list);
+	struct bio_entry *be, *tmp;
+
+	list_for_each_entry_safe(be, tmp, wait_list, list) {
+		struct bio *bio = be->bio;
+		int err;
+
+		wait_for_completion_io(&be->event);
+		err = be->error;
+		if (err == -EOPNOTSUPP)
+			err = 0;
+
+		if (err)
+			f2fs_msg(sbi->sb, KERN_INFO,
+				"Issue discard failed, ret: %d", err);
+
+		bio_put(bio);
+		list_del(&be->list);
+		kmem_cache_free(bio_entry_slab, be);
+	}
+}
+
+static void f2fs_submit_bio_wait_endio(struct bio *bio)
+{
+	struct bio_entry *be = (struct bio_entry *)bio->bi_private;
+
+	be->error = bio->bi_error;
+	complete(&be->event);
+}
+
+/* this function is copied from blkdev_issue_discard from block/blk-lib.c */
+int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi, sector_t sector,
+		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
+{
+	struct block_device *bdev = sbi->sb->s_bdev;
+	struct bio *bio = NULL;
+	int err;
+
+	err = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
+			&bio);
+	if (!err && bio) {
+		struct bio_entry *be = __add_bio_entry(sbi, bio);
+
+		bio->bi_private = be;
+		bio->bi_end_io = f2fs_submit_bio_wait_endio;
+		bio->bi_opf |= REQ_SYNC;
+		submit_bio(bio);
+	}
+
+	return err;
+}
+
 static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 				block_t blkstart, block_t blklen)
 {
@@ -597,7 +666,7 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 			sbi->discard_blks--;
 	}
 	trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
-	return blkdev_issue_discard(sbi->sb->s_bdev, start, len, GFP_NOFS, 0);
+	return __f2fs_issue_discard_async(sbi, start, len, GFP_NOFS, 0);
 }
 
 bool discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
@@ -719,11 +788,14 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	struct list_head *head = &(SM_I(sbi)->discard_list);
 	struct discard_entry *entry, *this;
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
+	struct blk_plug plug;
 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
 	unsigned int start = 0, end = -1;
 	unsigned int secno, start_segno;
 	bool force = (cpc->reason == CP_DISCARD);
 
+	blk_start_plug(&plug);
+
 	mutex_lock(&dirty_i->seglist_lock);
 
 	while (1) {
@@ -772,6 +844,8 @@ skip:
 		SM_I(sbi)->nr_discards -= entry->len;
 		kmem_cache_free(discard_entry_slab, entry);
 	}
+
+	blk_finish_plug(&plug);
 }
 
 static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
@@ -2457,6 +2531,7 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
 	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
 
 	INIT_LIST_HEAD(&sm_info->discard_list);
+	INIT_LIST_HEAD(&sm_info->wait_list);
 	sm_info->nr_discards = 0;
 	sm_info->max_discards = 0;
 
@@ -2600,10 +2675,15 @@ int __init create_segment_manager_caches(void)
 	if (!discard_entry_slab)
 		goto fail;
 
+	bio_entry_slab = f2fs_kmem_cache_create("bio_entry",
+			sizeof(struct bio_entry));
+	if (!bio_entry_slab)
+		goto destory_discard_entry;
+
 	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
 			sizeof(struct sit_entry_set));
 	if (!sit_entry_set_slab)
-		goto destory_discard_entry;
+		goto destroy_bio_entry;
 
 	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
 			sizeof(struct inmem_pages));
@@ -2613,6 +2693,8 @@ int __init create_segment_manager_caches(void)
 
 destroy_sit_entry_set:
 	kmem_cache_destroy(sit_entry_set_slab);
+destroy_bio_entry:
+	kmem_cache_destroy(bio_entry_slab);
 destory_discard_entry:
 	kmem_cache_destroy(discard_entry_slab);
 fail:
@@ -2622,6 +2704,7 @@ fail:
 void destroy_segment_manager_caches(void)
 {
 	kmem_cache_destroy(sit_entry_set_slab);
+	kmem_cache_destroy(bio_entry_slab);
 	kmem_cache_destroy(discard_entry_slab);
 	kmem_cache_destroy(inmem_entry_slab);
 }