[PATCH 07/13] btrfs: add check not to mount a spare device

[Anand Jain <anand.jain@oracle.com>]

From: Anand Jain <Anand.Jain@oracle.com>

Spare devices can be scanned but shouldn't be mountable.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Tested-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
---
 fs/btrfs/disk-io.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 65c9f19d8017..e9fca3bc7e42 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2811,6 +2811,14 @@ int open_ctree(struct super_block *sb,
 		goto fail_alloc;
 	}
 
+	if (btrfs_super_incompat_flags(disk_super) &
+			BTRFS_FEATURE_INCOMPAT_SPARE_DEV) {
+		/*You can only scan a spare device but not mount*/
+		printk(KERN_ERR "BTRFS: You can't mount a spare device\n");
+		err = -ENOTSUPP;
+		goto fail_alloc;
+	}
+
 	/*
 	 * Needn't use the lock because there is no other task which will
 	 * update the flag.
-- 
2.7.0