3 files changed, 11 insertions, 1 deletions

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 45c8cf1afe66..3eb724bb6594 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -43,11 +43,15 @@ int f2fs_check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
 bool f2fs_available_free_memory(struct f2fs_sb_info *sbi, int type)
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
 	struct sysinfo val;
 	unsigned long avail_ram;
 	unsigned long mem_size = 0;
 	bool res = false;
 
+	if (!nm_i)
+		return true;
+
 	si_meminfo(&val);
 
 	/* only uses low memory */
@@ -89,6 +93,10 @@ bool f2fs_available_free_memory(struct f2fs_sb_info *sbi, int type)
 		/* it allows 20% / total_ram for inmemory pages */
 		mem_size = get_pages(sbi, F2FS_INMEM_PAGES);
 		res = mem_size < (val.totalram / 5);
+	} else if (type == DISCARD_CACHE) {
+		mem_size = (atomic_read(&dcc->discard_cmd_cnt) *
+				sizeof(struct discard_cmd)) >> PAGE_SHIFT;
+		res = mem_size < (avail_ram * nm_i->ram_thresh / 100);
 	} else {
 		if (!sbi->sb->s_bdi->wb.dirty_exceeded)
 			return true;
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index f84541b57acb..7a45c0f10629 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -147,6 +147,7 @@ enum mem_type {
 	INO_ENTRIES,	/* indicates inode entries */
 	EXTENT_CACHE,	/* indicates extent cache */
 	INMEM_PAGES,	/* indicates inmemory pages */
+	DISCARD_CACHE,	/* indicates memory of cached discard cmds */
 	BASE_CHECK,	/* check kernel status */
 };
 
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 33cb8aa5ec8f..ad48f1f16387 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1762,7 +1762,8 @@ static int issue_discard_thread(void *data)
 		if (!atomic_read(&dcc->discard_cmd_cnt))
 			continue;
 
-		if (sbi->gc_mode == GC_URGENT_HIGH)
+		if (sbi->gc_mode == GC_URGENT_HIGH ||
+			!f2fs_available_free_memory(sbi, DISCARD_CACHE))
 			__init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1);
 
 		sb_start_intwrite(sbi->sb);