Don't prevent removal of devices that break raid reqs

[Alexandre Oliva <oliva@lsd.ic.unicamp.br>]

Instead of preventing the removal of devices that would render existing
raid10 or raid1 impossible, warn but go ahead with it; the rebalancing
code is smart enough to use different block group types.

Should the refusal remain, so that we'd only proceed with a
newly-introduced --force option or so?

Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
---
 fs/btrfs/volumes.c |   12 ++++--------
 1 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 4d5b29f..507afca 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1281,18 +1281,14 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
 	    root->fs_info->fs_devices->num_devices <= 4) {
-		printk(KERN_ERR "btrfs: unable to go below four devices "
-		       "on raid10\n");
-		ret = -EINVAL;
-		goto out;
+		printk(KERN_ERR "btrfs: going below four devices "
+		       "will turn raid10 into raid1\n");
 	}
 
 	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
 	    root->fs_info->fs_devices->num_devices <= 2) {
-		printk(KERN_ERR "btrfs: unable to go below two "
-		       "devices on raid1\n");
-		ret = -EINVAL;
-		goto out;
+		printk(KERN_ERR "btrfs: going below two devices "
+		       "will lose raid1 redundancy\n");
 	}
 
 	if (strcmp(device_path, "missing") == 0) {
-- 
1.7.4.4


-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer