1 files changed, 44 insertions, 1 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 85e546ffe3c7..1e7a9bac31ab 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3065,7 +3065,7 @@ out:
         return ret;
 }
 
-void update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
+void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
                                struct btrfs_ioctl_balance_args *bargs)
 {
         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
@@ -3082,6 +3082,14 @@ void update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
+
+        if (lock) {
+                spin_lock(&fs_info->balance_lock);
+                memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
+                spin_unlock(&fs_info->balance_lock);
+        } else {
+                memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
+        }
 }
 
 static long btrfs_ioctl_balance(struct btrfs_root *root, void __user *arg)
@@ -3181,6 +3189,39 @@ static long btrfs_ioctl_balance_ctl(struct btrfs_root *root, int cmd)
         return -EINVAL;
 }
 
+static long btrfs_ioctl_balance_progress(struct btrfs_root *root,
+                                         void __user *arg)
+{
+        struct btrfs_fs_info *fs_info = root->fs_info;
+        struct btrfs_ioctl_balance_args *bargs;
+        int ret = 0;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        mutex_lock(&fs_info->balance_mutex);
+        if (!fs_info->balance_ctl) {
+                ret = -ENOTCONN;
+                goto out;
+        }
+
+        bargs = kzalloc(sizeof(*bargs), GFP_NOFS);
+        if (!bargs) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        update_ioctl_balance_args(fs_info, 1, bargs);
+
+        if (copy_to_user(arg, bargs, sizeof(*bargs)))
+                ret = -EFAULT;
+
+        kfree(bargs);
+out:
+        mutex_unlock(&fs_info->balance_mutex);
+        return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
                 cmd, unsigned long arg)
 {
@@ -3261,6 +3302,8 @@ long btrfs_ioctl(struct file *file, unsigned int
                 return btrfs_ioctl_balance(root, argp);
         case BTRFS_IOC_BALANCE_CTL:
                 return btrfs_ioctl_balance_ctl(root, arg);
+        case BTRFS_IOC_BALANCE_PROGRESS:
+                return btrfs_ioctl_balance_progress(root, argp);
         }
 
         return -ENOTTY;