Btrfs: add balance progress reporting

[deliverable/linux.git] / fs / btrfs / ioctl.c

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 85e546ffe3c7919c7c2c0b3c52f594fe7bd59f17..1e7a9bac31ab9f6774e98e76264893752921ff36 100644 (file)
--- 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;