Hello Jan,
> The function is separated into a preparation part and the three accounting
> steps mentioned in the qgroups documentation. The goal is to make steps two
> and three usable by the rescan functionality. A side effect is that the
> function is restructured into readable subunits.
How about renaming the three functions like:
1> qgroup_walk_old_roots()
2> qgroup_walk_new_root()
3> qgroup_rewalk_old_root()
I'd like this function to be meaningful, but not just step1,2,3.
Maybe you can think out better function name.
Thanks,
Wang
>
> Signed-off-by: Jan Schmidt <list.bt...@jan-o-sch.net>
> ---
> fs/btrfs/qgroup.c | 212
> ++++++++++++++++++++++++++++++-----------------------
> 1 files changed, 121 insertions(+), 91 deletions(-)
>
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index b44124d..c38a0c5 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -1075,6 +1075,122 @@ int btrfs_qgroup_record_ref(struct btrfs_trans_handle
> *trans,
> return 0;
> }
>
> +static void qgroup_account_ref_step1(struct btrfs_fs_info *fs_info,
> + struct ulist *roots, struct ulist *tmp,
> + u64 seq)
> +{
> + struct ulist_node *unode;
> + struct ulist_iterator uiter;
> + struct ulist_node *tmp_unode;
> + struct ulist_iterator tmp_uiter;
> + struct btrfs_qgroup *qg;
> +
> + ULIST_ITER_INIT(&uiter);
> + while ((unode = ulist_next(roots, &uiter))) {
> + qg = find_qgroup_rb(fs_info, unode->val);
> + if (!qg)
> + continue;
> +
> + ulist_reinit(tmp);
> + /* XXX id not needed */
> + ulist_add(tmp, qg->qgroupid, (u64)(uintptr_t)qg, GFP_ATOMIC);
> + ULIST_ITER_INIT(&tmp_uiter);
> + while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
> + struct btrfs_qgroup_list *glist;
> +
> + qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
> + if (qg->refcnt < seq)
> + qg->refcnt = seq + 1;
> + else
> + ++qg->refcnt;
> +
> + list_for_each_entry(glist, &qg->groups, next_group) {
> + ulist_add(tmp, glist->group->qgroupid,
> + (u64)(uintptr_t)glist->group,
> + GFP_ATOMIC);
> + }
> + }
> + }
> +}
> +
> +static void qgroup_account_ref_step2(struct btrfs_fs_info *fs_info,
> + struct ulist *roots, struct ulist *tmp,
> + u64 seq, int sgn, u64 num_bytes,
> + struct btrfs_qgroup *qgroup)
> +{
> + struct ulist_node *unode;
> + struct ulist_iterator uiter;
> + struct btrfs_qgroup *qg;
> + struct btrfs_qgroup_list *glist;
> +
> + ulist_reinit(tmp);
> + ulist_add(tmp, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
> +
> + ULIST_ITER_INIT(&uiter);
> + while ((unode = ulist_next(tmp, &uiter))) {
> +
> + qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
> + if (qg->refcnt < seq) {
> + /* not visited by step 1 */
> + qg->rfer += sgn * num_bytes;
> + qg->rfer_cmpr += sgn * num_bytes;
> + if (roots->nnodes == 0) {
> + qg->excl += sgn * num_bytes;
> + qg->excl_cmpr += sgn * num_bytes;
> + }
> + qgroup_dirty(fs_info, qg);
> + }
> + WARN_ON(qg->tag >= seq);
> + qg->tag = seq;
> +
> + list_for_each_entry(glist, &qg->groups, next_group) {
> + ulist_add(tmp, glist->group->qgroupid,
> + (uintptr_t)glist->group, GFP_ATOMIC);
> + }
> + }
> +}
> +
> +static void qgroup_account_ref_step3(struct btrfs_fs_info *fs_info,
> + struct ulist *roots, struct ulist *tmp,
> + u64 seq, int sgn, u64 num_bytes)
> +{
> + struct ulist_node *unode;
> + struct ulist_iterator uiter;
> + struct btrfs_qgroup *qg;
> + struct ulist_node *tmp_unode;
> + struct ulist_iterator tmp_uiter;
> +
> + ULIST_ITER_INIT(&uiter);
> + while ((unode = ulist_next(roots, &uiter))) {
> + qg = find_qgroup_rb(fs_info, unode->val);
> + if (!qg)
> + continue;
> +
> + ulist_reinit(tmp);
> + ulist_add(tmp, qg->qgroupid, (uintptr_t)qg, GFP_ATOMIC);
> + ULIST_ITER_INIT(&tmp_uiter);
> + while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
> + struct btrfs_qgroup_list *glist;
> +
> + qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
> + if (qg->tag == seq)
> + continue;
> +
> + if (qg->refcnt - seq == roots->nnodes) {
> + qg->excl -= sgn * num_bytes;
> + qg->excl_cmpr -= sgn * num_bytes;
> + qgroup_dirty(fs_info, qg);
> + }
> +
> + list_for_each_entry(glist, &qg->groups, next_group) {
> + ulist_add(tmp, glist->group->qgroupid,
> + (uintptr_t)glist->group,
> + GFP_ATOMIC);
> + }
> + }
> + }
> +}
> +
> /*
> * btrfs_qgroup_account_ref is called for every ref that is added to or
> deleted
> * from the fs. First, all roots referencing the extent are searched, and
> @@ -1090,10 +1206,8 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle
> *trans,
> struct btrfs_root *quota_root;
> u64 ref_root;
> struct btrfs_qgroup *qgroup;
> - struct ulist_node *unode;
> struct ulist *roots = NULL;
> struct ulist *tmp = NULL;
> - struct ulist_iterator uiter;
> u64 seq;
> int ret = 0;
> int sgn;
> @@ -1175,103 +1289,19 @@ int btrfs_qgroup_account_ref(struct
> btrfs_trans_handle *trans,
> seq = fs_info->qgroup_seq;
> fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */
>
> - ULIST_ITER_INIT(&uiter);
> - while ((unode = ulist_next(roots, &uiter))) {
> - struct ulist_node *tmp_unode;
> - struct ulist_iterator tmp_uiter;
> - struct btrfs_qgroup *qg;
> -
> - qg = find_qgroup_rb(fs_info, unode->val);
> - if (!qg)
> - continue;
> -
> - ulist_reinit(tmp);
> - /* XXX id not needed */
> - ulist_add(tmp, qg->qgroupid, (u64)(uintptr_t)qg, GFP_ATOMIC);
> - ULIST_ITER_INIT(&tmp_uiter);
> - while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
> - struct btrfs_qgroup_list *glist;
> -
> - qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
> - if (qg->refcnt < seq)
> - qg->refcnt = seq + 1;
> - else
> - ++qg->refcnt;
> -
> - list_for_each_entry(glist, &qg->groups, next_group) {
> - ulist_add(tmp, glist->group->qgroupid,
> - (u64)(uintptr_t)glist->group,
> - GFP_ATOMIC);
> - }
> - }
> - }
> + qgroup_account_ref_step1(fs_info, roots, tmp, seq);
>
> /*
> * step 2: walk from the new root
> */
> - ulist_reinit(tmp);
> - ulist_add(tmp, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC);
> - ULIST_ITER_INIT(&uiter);
> - while ((unode = ulist_next(tmp, &uiter))) {
> - struct btrfs_qgroup *qg;
> - struct btrfs_qgroup_list *glist;
> -
> - qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux;
> - if (qg->refcnt < seq) {
> - /* not visited by step 1 */
> - qg->rfer += sgn * node->num_bytes;
> - qg->rfer_cmpr += sgn * node->num_bytes;
> - if (roots->nnodes == 0) {
> - qg->excl += sgn * node->num_bytes;
> - qg->excl_cmpr += sgn * node->num_bytes;
> - }
> - qgroup_dirty(fs_info, qg);
> - }
> - WARN_ON(qg->tag >= seq);
> - qg->tag = seq;
> -
> - list_for_each_entry(glist, &qg->groups, next_group) {
> - ulist_add(tmp, glist->group->qgroupid,
> - (uintptr_t)glist->group, GFP_ATOMIC);
> - }
> - }
> + qgroup_account_ref_step2(fs_info, roots, tmp, seq, sgn,
> + node->num_bytes, qgroup);
>
> /*
> * step 3: walk again from old refs
> */
> - ULIST_ITER_INIT(&uiter);
> - while ((unode = ulist_next(roots, &uiter))) {
> - struct btrfs_qgroup *qg;
> - struct ulist_node *tmp_unode;
> - struct ulist_iterator tmp_uiter;
> -
> - qg = find_qgroup_rb(fs_info, unode->val);
> - if (!qg)
> - continue;
> -
> - ulist_reinit(tmp);
> - ulist_add(tmp, qg->qgroupid, (uintptr_t)qg, GFP_ATOMIC);
> - ULIST_ITER_INIT(&tmp_uiter);
> - while ((tmp_unode = ulist_next(tmp, &tmp_uiter))) {
> - struct btrfs_qgroup_list *glist;
> -
> - qg = (struct btrfs_qgroup *)(uintptr_t)tmp_unode->aux;
> - if (qg->tag == seq)
> - continue;
> -
> - if (qg->refcnt - seq == roots->nnodes) {
> - qg->excl -= sgn * node->num_bytes;
> - qg->excl_cmpr -= sgn * node->num_bytes;
> - qgroup_dirty(fs_info, qg);
> - }
> -
> - list_for_each_entry(glist, &qg->groups, next_group) {
> - ulist_add(tmp, glist->group->qgroupid,
> - (uintptr_t)glist->group,
> - GFP_ATOMIC);
> - }
> - }
> - }
> + qgroup_account_ref_step3(fs_info, roots, tmp, seq, sgn,
> + node->num_bytes);
> ret = 0;
> unlock:
> spin_unlock(&fs_info->qgroup_lock);
--
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