Btrfs: rescan for qgroups
If qgroup tracking is out of sync, a rescan operation can be started. It
iterates the complete extent tree and recalculates all qgroup tracking data.
This is an expensive operation and should not be used unless required.
A filesystem under rescan can still be umounted. The rescan continues on the
next mount. Status information is provided with a separate ioctl while a
rescan operation is in progress.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index a74edc7..f5f6af3 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3701,12 +3701,10 @@
}
down_write(&root->fs_info->subvol_sem);
- if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
- trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
- if (IS_ERR(trans)) {
- ret = PTR_ERR(trans);
- goto out;
- }
+ trans = btrfs_start_transaction(root->fs_info->tree_root, 2);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out;
}
switch (sa->cmd) {
@@ -3716,9 +3714,6 @@
case BTRFS_QUOTA_CTL_DISABLE:
ret = btrfs_quota_disable(trans, root->fs_info);
break;
- case BTRFS_QUOTA_CTL_RESCAN:
- ret = btrfs_quota_rescan(root->fs_info);
- break;
default:
ret = -EINVAL;
break;
@@ -3727,11 +3722,9 @@
if (copy_to_user(arg, sa, sizeof(*sa)))
ret = -EFAULT;
- if (trans) {
- err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
- if (err && !ret)
- ret = err;
- }
+ err = btrfs_commit_transaction(trans, root->fs_info->tree_root);
+ if (err && !ret)
+ ret = err;
out:
kfree(sa);
up_write(&root->fs_info->subvol_sem);
@@ -3886,6 +3879,64 @@
return ret;
}
+static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
+{
+ struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
+ struct btrfs_ioctl_quota_rescan_args *qsa;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ ret = mnt_want_write_file(file);
+ if (ret)
+ return ret;
+
+ qsa = memdup_user(arg, sizeof(*qsa));
+ if (IS_ERR(qsa)) {
+ ret = PTR_ERR(qsa);
+ goto drop_write;
+ }
+
+ if (qsa->flags) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = btrfs_qgroup_rescan(root->fs_info);
+
+out:
+ kfree(qsa);
+drop_write:
+ mnt_drop_write_file(file);
+ return ret;
+}
+
+static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
+{
+ struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
+ struct btrfs_ioctl_quota_rescan_args *qsa;
+ int ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ qsa = kzalloc(sizeof(*qsa), GFP_NOFS);
+ if (!qsa)
+ return -ENOMEM;
+
+ if (root->fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
+ qsa->flags = 1;
+ qsa->progress = root->fs_info->qgroup_rescan_progress.objectid;
+ }
+
+ if (copy_to_user(arg, qsa, sizeof(*qsa)))
+ ret = -EFAULT;
+
+ kfree(qsa);
+ return ret;
+}
+
static long btrfs_ioctl_set_received_subvol(struct file *file,
void __user *arg)
{
@@ -4124,6 +4175,10 @@
return btrfs_ioctl_qgroup_create(file, argp);
case BTRFS_IOC_QGROUP_LIMIT:
return btrfs_ioctl_qgroup_limit(file, argp);
+ case BTRFS_IOC_QUOTA_RESCAN:
+ return btrfs_ioctl_quota_rescan(file, argp);
+ case BTRFS_IOC_QUOTA_RESCAN_STATUS:
+ return btrfs_ioctl_quota_rescan_status(file, argp);
case BTRFS_IOC_DEV_REPLACE:
return btrfs_ioctl_dev_replace(root, argp);
case BTRFS_IOC_GET_FSLABEL: