Btrfs: add ioctl to get and reset the device stats
An ioctl interface is added to get the device statistic counters.
A second ioctl is added to atomically get and reset these counters.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 15baf94..0f8c354 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3046,6 +3046,28 @@
return ret;
}
+static long btrfs_ioctl_get_dev_stats(struct btrfs_root *root,
+ void __user *arg, int reset_after_read)
+{
+ struct btrfs_ioctl_get_dev_stats *sa;
+ int ret;
+
+ if (reset_after_read && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ sa = memdup_user(arg, sizeof(*sa));
+ if (IS_ERR(sa))
+ return PTR_ERR(sa);
+
+ ret = btrfs_get_dev_stats(root, sa, reset_after_read);
+
+ if (copy_to_user(arg, sa, sizeof(*sa)))
+ ret = -EFAULT;
+
+ kfree(sa);
+ return ret;
+}
+
static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
{
int ret = 0;
@@ -3434,6 +3456,10 @@
return btrfs_ioctl_balance_ctl(root, arg);
case BTRFS_IOC_BALANCE_PROGRESS:
return btrfs_ioctl_balance_progress(root, argp);
+ case BTRFS_IOC_GET_DEV_STATS:
+ return btrfs_ioctl_get_dev_stats(root, argp, 0);
+ case BTRFS_IOC_GET_AND_RESET_DEV_STATS:
+ return btrfs_ioctl_get_dev_stats(root, argp, 1);
}
return -ENOTTY;