[PATCH] btrfs: SSD related mount option dependency rework.

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

According to Documentations/filesystem/btrfs.txt, ssd/ssd_spread/nossd
has their own dependency(See below), but only ssd_spread implying ssd is
implemented.

ssd_spread implies ssd, conflicts nossd.
ssd conflicts nossd.
nossd conflicts ssd and ssd_spread.

This patch adds ssd{,_spread} confliction with nossd.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 fs/btrfs/super.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8e16bca..2508a16 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -515,19 +515,22 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
 						   compress_type);
 			}
 			break;
-		case Opt_ssd:
-			btrfs_set_and_info(root, SSD,
-					   "use ssd allocation scheme");
-			break;
 		case Opt_ssd_spread:
 			btrfs_set_and_info(root, SSD_SPREAD,
 					   "use spread ssd allocation scheme");
+			/* suppress the ssd mount option log */
 			btrfs_set_opt(info->mount_opt, SSD);
+			/* fall through for other ssd routine */
+		case Opt_ssd:
+			btrfs_set_and_info(root, SSD,
+					   "use ssd allocation scheme");
+			btrfs_clear_opt(info->mount_opt, NOSSD);
 			break;
 		case Opt_nossd:
 			btrfs_set_and_info(root, NOSSD,
 					     "not using ssd allocation scheme");
 			btrfs_clear_opt(info->mount_opt, SSD);
+			btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
 			break;
 		case Opt_barrier:
 			btrfs_clear_and_info(root, NOBARRIER,
-- 
2.0.3