Hi, Qu, On 2015/09/08 18:01, Qu Wenruo wrote: > New function insert_data_ranges() will insert non-overlap reserve ranges > into reserve map. > > It provides the basis for later qgroup reserve map implement. > > Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> > --- > fs/btrfs/qgroup.c | 124 > ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 124 insertions(+) > > diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c > index fc24fc3..a4e3af4 100644 > --- a/fs/btrfs/qgroup.c > +++ b/fs/btrfs/qgroup.c > @@ -2577,6 +2577,130 @@ find_reserve_range(struct btrfs_qgroup_data_rsv_map > *map, u64 start) > } > > /* > + * Insert one data range
> + * [start,len) here won't overflap with each other. overlap Thanks, Tsutomu > + * > + * Return 0 if range is inserted and tmp is not used. > + * Return > 0 if range is inserted and tmp is used. > + * No catchable error case. Only possible error will cause BUG_ON() as > + * that's logical error. > + */ > +static int insert_data_range(struct btrfs_qgroup_data_rsv_map *map, > + struct data_rsv_range *tmp, > + u64 start, u64 len) > +{ > + struct rb_node **p = &map->root.rb_node; > + struct rb_node *parent = NULL; > + struct rb_node *tmp_node = NULL; > + struct data_rsv_range *range = NULL; > + struct data_rsv_range *prev_range = NULL; > + struct data_rsv_range *next_range = NULL; > + int prev_merged = 0; > + int next_merged = 0; > + int ret = 0; > + > + while (*p) { > + parent = *p; > + range = rb_entry(parent, struct data_rsv_range, node); > + if (range->start < start) > + p = &(*p)->rb_right; > + else if (range->start > start) > + p = &(*p)->rb_left; > + else > + BUG_ON(1); > + } > + > + /* Empty tree, goto isolated case */ > + if (!range) > + goto insert_isolated; > + > + /* get adjusted ranges */ > + if (range->start < start) { > + prev_range = range; > + tmp_node = rb_next(parent); > + if (tmp) > + next_range = rb_entry(tmp_node, struct data_rsv_range, > + node); > + } else { > + next_range = range; > + tmp_node = rb_prev(parent); > + if (tmp) > + prev_range = rb_entry(tmp_node, struct data_rsv_range, > + node); > + } > + > + /* try to merge with previous and next ranges */ > + if (prev_range && prev_range->start + prev_range->len == start) { > + prev_merged = 1; > + prev_range->len += len; > + } > + if (next_range && start + len == next_range->start) { > + next_merged = 1; > + > + /* > + * the range can be merged with adjusted two ranges into one, > + * remove the tailing range. > + */ > + if (prev_merged) { > + prev_range->len += next_range->len; > + rb_erase(&next_range->node, &map->root); > + kfree(next_range); > + } else { > + next_range->start = start; > + next_range->len += len; > + } > + } > + > +insert_isolated: > + /* isolated case, need to insert range now */ > + if (!next_merged && !prev_merged) { > + BUG_ON(!tmp); > + > + tmp->start = start; > + tmp->len = len; > + rb_link_node(&tmp->node, parent, p); > + rb_insert_color(&tmp->node, &map->root); > + ret = 1; > + } > + return ret; > +} > + > +/* > + * insert reserve range and merge them if possible > + * > + * Return 0 if all inserted and tmp not used > + * Return > 0 if all inserted and tmp used > + * No catchable error return value. > + */ > +static int insert_data_ranges(struct btrfs_qgroup_data_rsv_map *map, > + struct data_rsv_range *tmp, > + struct ulist *insert_list) > +{ > + struct ulist_node *unode; > + struct ulist_iterator uiter; > + int tmp_used = 0; > + int ret = 0; > + > + ULIST_ITER_INIT(&uiter); > + while ((unode = ulist_next(insert_list, &uiter))) { > + ret = insert_data_range(map, tmp, unode->val, unode->aux); > + > + /* > + * insert_data_range() won't return error return value, > + * no need to hanle <0 case. > + * > + * Also tmp should be used at most one time, so clear it to > + * NULL to cooperate with sanity check in insert_data_range(). > + */ > + if (ret > 0) { > + tmp_used = 1; > + tmp = NULL; > + } > + } > + return tmp_used; > +} > + > +/* > * Init data_rsv_map for a given inode. > * > * This is needed at write time as quota can be disabled and then enabled > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html