[PATCH v2] f2fs: enable realtime discard iff device supports discard

[Chao Yu]

Let's only enable realtime discard if and only if device supports
discard functionality.

Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
---
v2:
- don't give EINVAL if device doesn't support discard for "-o discard"
mountoption to avoid break userspace behavior.
 fs/f2fs/super.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f5148f2fd884..27c78c96d866 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -661,10 +661,14 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 				return -EINVAL;
 			break;
 		case Opt_discard:
+			if (!f2fs_hw_support_discard(sbi)) {
+				f2fs_warn(sbi, "device does not support discard");
+				break;
+			}
 			set_opt(sbi, DISCARD);
 			break;
 		case Opt_nodiscard:
-			if (f2fs_sb_has_blkzoned(sbi)) {
+			if (f2fs_hw_should_discard(sbi)) {
 				f2fs_warn(sbi, "discard is required for zoned block devices");
 				return -EINVAL;
 			}
@@ -2001,7 +2005,8 @@ static void default_options(struct f2fs_sb_info *sbi)
 	F2FS_OPTION(sbi).unusable_cap = 0;
 	sbi->sb->s_flags |= SB_LAZYTIME;
 	set_opt(sbi, FLUSH_MERGE);
-	set_opt(sbi, DISCARD);
+	if (f2fs_hw_support_discard(sbi) || f2fs_hw_should_discard(sbi))
+		set_opt(sbi, DISCARD);
 	if (f2fs_sb_has_blkzoned(sbi)) {
 		F2FS_OPTION(sbi).fs_mode = FS_MODE_LFS;
 		F2FS_OPTION(sbi).discard_unit = DISCARD_UNIT_SECTION;
-- 
2.32.0