Btrfs: add qgroup ioctls

Ioctls to control the qgroup feature like adding and
removing qgroups and assigning qgroups.

Signed-off-by: Arne Jansen <sensille@gmx.net>

2 files changed, 212 insertions, 0 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0e92e5763005..55a7283a9e18 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3390,6 +3390,183 @@ out:
         return ret;
 }
 
+static long btrfs_ioctl_quota_ctl(struct btrfs_root *root, void __user *arg)
+{
+        struct btrfs_ioctl_quota_ctl_args *sa;
+        struct btrfs_trans_handle *trans = NULL;
+        int ret;
+        int err;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        if (root->fs_info->sb->s_flags & MS_RDONLY)
+                return -EROFS;
+
+        sa = memdup_user(arg, sizeof(*sa));
+        if (IS_ERR(sa))
+                return PTR_ERR(sa);
+
+        if (sa->cmd != BTRFS_QUOTA_CTL_RESCAN) {
+                trans = btrfs_start_transaction(root, 2);
+                if (IS_ERR(trans)) {
+                        ret = PTR_ERR(trans);
+                        goto out;
+                }
+        }
+
+        switch (sa->cmd) {
+        case BTRFS_QUOTA_CTL_ENABLE:
+                ret = btrfs_quota_enable(trans, root->fs_info);
+                break;
+        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;
+        }
+
+        if (copy_to_user(arg, sa, sizeof(*sa)))
+                ret = -EFAULT;
+
+        if (trans) {
+                err = btrfs_commit_transaction(trans, root);
+                if (err && !ret)
+                        ret = err;
+        }
+
+out:
+        kfree(sa);
+        return ret;
+}
+
+static long btrfs_ioctl_qgroup_assign(struct btrfs_root *root, void __user *arg)
+{
+        struct btrfs_ioctl_qgroup_assign_args *sa;
+        struct btrfs_trans_handle *trans;
+        int ret;
+        int err;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        if (root->fs_info->sb->s_flags & MS_RDONLY)
+                return -EROFS;
+
+        sa = memdup_user(arg, sizeof(*sa));
+        if (IS_ERR(sa))
+                return PTR_ERR(sa);
+
+        trans = btrfs_join_transaction(root);
+        if (IS_ERR(trans)) {
+                ret = PTR_ERR(trans);
+                goto out;
+        }
+
+        /* FIXME: check if the IDs really exist */
+        if (sa->assign) {
+                ret = btrfs_add_qgroup_relation(trans, root->fs_info,
+                                                sa->src, sa->dst);
+        } else {
+                ret = btrfs_del_qgroup_relation(trans, root->fs_info,
+                                                sa->src, sa->dst);
+        }
+
+        err = btrfs_end_transaction(trans, root);
+        if (err && !ret)
+                ret = err;
+
+out:
+        kfree(sa);
+        return ret;
+}
+
+static long btrfs_ioctl_qgroup_create(struct btrfs_root *root, void __user *arg)
+{
+        struct btrfs_ioctl_qgroup_create_args *sa;
+        struct btrfs_trans_handle *trans;
+        int ret;
+        int err;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        if (root->fs_info->sb->s_flags & MS_RDONLY)
+                return -EROFS;
+
+        sa = memdup_user(arg, sizeof(*sa));
+        if (IS_ERR(sa))
+                return PTR_ERR(sa);
+
+        trans = btrfs_join_transaction(root);
+        if (IS_ERR(trans)) {
+                ret = PTR_ERR(trans);
+                goto out;
+        }
+
+        /* FIXME: check if the IDs really exist */
+        if (sa->create) {
+                ret = btrfs_create_qgroup(trans, root->fs_info, sa->qgroupid,
+                                          NULL);
+        } else {
+                ret = btrfs_remove_qgroup(trans, root->fs_info, sa->qgroupid);
+        }
+
+        err = btrfs_end_transaction(trans, root);
+        if (err && !ret)
+                ret = err;
+
+out:
+        kfree(sa);
+        return ret;
+}
+
+static long btrfs_ioctl_qgroup_limit(struct btrfs_root *root, void __user *arg)
+{
+        struct btrfs_ioctl_qgroup_limit_args *sa;
+        struct btrfs_trans_handle *trans;
+        int ret;
+        int err;
+        u64 qgroupid;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        if (root->fs_info->sb->s_flags & MS_RDONLY)
+                return -EROFS;
+
+        sa = memdup_user(arg, sizeof(*sa));
+        if (IS_ERR(sa))
+                return PTR_ERR(sa);
+
+        trans = btrfs_join_transaction(root);
+        if (IS_ERR(trans)) {
+                ret = PTR_ERR(trans);
+                goto out;
+        }
+
+        qgroupid = sa->qgroupid;
+        if (!qgroupid) {
+                /* take the current subvol as qgroup */
+                qgroupid = root->root_key.objectid;
+        }
+
+        /* FIXME: check if the IDs really exist */
+        ret = btrfs_limit_qgroup(trans, root->fs_info, qgroupid, &sa->lim);
+
+        err = btrfs_end_transaction(trans, root);
+        if (err && !ret)
+                ret = err;
+
+out:
+        kfree(sa);
+        return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
                 cmd, unsigned long arg)
 {
@@ -3476,6 +3653,14 @@ long btrfs_ioctl(struct file *file, unsigned int
                 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);
+        case BTRFS_IOC_QUOTA_CTL:
+                return btrfs_ioctl_quota_ctl(root, argp);
+        case BTRFS_IOC_QGROUP_ASSIGN:
+                return btrfs_ioctl_qgroup_assign(root, argp);
+        case BTRFS_IOC_QGROUP_CREATE:
+                return btrfs_ioctl_qgroup_create(root, argp);
+        case BTRFS_IOC_QGROUP_LIMIT:
+                return btrfs_ioctl_qgroup_limit(root, argp);
         }
 
         return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index a8a2230f4c5c..9dd50c4656b3 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -319,6 +319,25 @@ struct btrfs_ioctl_get_dev_stats {
         __u64 unused[128 - 2 - BTRFS_DEV_STAT_VALUES_MAX]; /* pad to 1k */
 };
 
+#define BTRFS_QUOTA_CTL_ENABLE  1
+#define BTRFS_QUOTA_CTL_DISABLE 2
+#define BTRFS_QUOTA_CTL_RESCAN  3
+struct btrfs_ioctl_quota_ctl_args {
+        __u64 cmd;
+        __u64 status;
+};
+
+struct btrfs_ioctl_qgroup_assign_args {
+        __u64 assign;
+        __u64 src;
+        __u64 dst;
+};
+
+struct btrfs_ioctl_qgroup_create_args {
+        __u64 create;
+        __u64 qgroupid;
+};
+
 #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
                                    struct btrfs_ioctl_vol_args)
 #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -388,4 +407,12 @@ struct btrfs_ioctl_get_dev_stats {
 #define BTRFS_IOC_GET_AND_RESET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 53, \
                                         struct btrfs_ioctl_get_dev_stats)
 
+#define BTRFS_IOC_QUOTA_CTL _IOWR(BTRFS_IOCTL_MAGIC, 40, \
+                               struct btrfs_ioctl_quota_ctl_args)
+#define BTRFS_IOC_QGROUP_ASSIGN _IOW(BTRFS_IOCTL_MAGIC, 41, \
+                               struct btrfs_ioctl_qgroup_assign_args)
+#define BTRFS_IOC_QGROUP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 42, \
+                               struct btrfs_ioctl_qgroup_create_args)
+#define BTRFS_IOC_QGROUP_LIMIT _IOR(BTRFS_IOCTL_MAGIC, 43, \
+                               struct btrfs_ioctl_qgroup_limit_args)
 #endif