1 files changed, 27 insertions, 1 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 29b3a94933f0..f572c53dda4f 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3072,6 +3072,11 @@ void update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
 
         bargs->flags = bctl->flags;
 
+        if (atomic_read(&fs_info->balance_running))
+                bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
+        if (atomic_read(&fs_info->balance_pause_req))
+                bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
+
         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
@@ -3103,6 +3108,11 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
                 bargs = NULL;
         }
 
+        if (fs_info->balance_ctl) {
+                ret = -EINPROGRESS;
+                goto out_bargs;
+        }
+
         bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
         if (!bctl) {
                 ret = -ENOMEM;
@@ -3123,7 +3133,8 @@ static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
 
         ret = btrfs_balance(bctl, bargs);
         /*
-         * bctl is freed in __cancel_balance
+         * bctl is freed in __cancel_balance or in free_fs_info if
+         * restriper was paused all the way until unmount
          */
         if (arg) {
                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
@@ -3138,6 +3149,19 @@ out:
         return ret;
 }
 
+static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
+{
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        switch (cmd) {
+        case BTRFS_BALANCE_CTL_PAUSE:
+                return btrfs_pause_balance(root->fs_info);
+        }
+
+        return -EINVAL;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
                 cmd, unsigned long arg)
 {
@@ -3216,6 +3240,8 @@ long btrfs_ioctl(struct file *file, unsigned int
                 return btrfs_ioctl_scrub_progress(root, argp);
         case BTRFS_IOC_BALANCE_V2:
                 return btrfs_ioctl_balance(root, argp);
+        case BTRFS_IOC_BALANCE_CTL:
+                return btrfs_ioctl_balance_ctl(root, arg);
         }
 
         return -ENOTTY;