Introduce new function reserve_data_range(). This function will find non-overlap range and to insert it into reserve map using previously introduced functions.
This provides the basis for later per inode reserve map implement. Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> --- v2: Add needed parameter for later trace functions --- fs/btrfs/qgroup.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index b690b02..3bdf28e 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2701,6 +2701,101 @@ static int insert_data_ranges(struct btrfs_qgroup_data_rsv_map *map, } /* + * Check qgroup limit and insert dirty range into reserve_map. + * + * Must be called with map->lock hold + */ +static int reserve_data_range(struct btrfs_root *root, + struct btrfs_qgroup_data_rsv_map *map, + struct data_rsv_range *tmp, + struct ulist *insert_list, u64 start, u64 len, + u64 *reserved) +{ + struct data_rsv_range *range; + u64 cur_start = 0; + u64 cur_len = 0; + u64 reserve = 0; + int ret = 0; + + range = find_reserve_range(map, start); + /* empty tree, insert the whole range */ + if (!range) { + reserve = len; + ret = ulist_add(insert_list, start, len, GFP_ATOMIC); + if (ret < 0) + return ret; + goto insert; + } + + /* For case range is covering the leading part */ + if (range->start <= start && range->start + range->len > start) + cur_start = range->start + range->len; + else + cur_start = start; + + /* + * iterate until the end of the range. + * Like the following: + * + * |<--------desired---------------------->| + *|//1//| |////2//| |///3///| <- exists + * Then we will need to insert the following + * |\\\4\\\| |\\\5\\\| |\\\6\\\| + * And only add qgroup->reserved for rang 4,5,6. + */ + while (cur_start < start + len) { + struct rb_node *next_node; + u64 next_start; + + if (range->start + range->len <= cur_start) { + /* + * Move to next range if current range is before + * cur_start + * e.g range is 1, cur_start is the end of range 1. + */ + next_node = rb_next(&range->node); + if (!next_node) { + /* + * no next range, fill the rest + * e.g range is 3, cur_start is end of range 3. + */ + cur_len = start + len - cur_start; + next_start = start + len; + } else { + range = rb_entry(next_node, + struct data_rsv_range, node); + cur_len = min(range->start, start + len) - + cur_start; + next_start = range->start + range->len; + } + } else { + /* + * current range is already after cur_start + * e.g range is 2, cur_start is end of range 1. + */ + cur_len = min(range->start, start + len) - cur_start; + next_start = range->start + range->len; + } + reserve += cur_len; + ret = ulist_add(insert_list, cur_start, cur_len, GFP_ATOMIC); + if (ret < 0) + return ret; + + cur_start = next_start; + } +insert: + ret = btrfs_qgroup_reserve(root, reserve); + if (ret < 0) + return ret; + /* ranges must be inserted after we are sure it has enough space */ + ret = insert_data_ranges(map, tmp, insert_list); + map->reserved += reserve; + if (reserved) + *reserved = reserve; + return ret; +} + +/* * Init data_rsv_map for a given inode. * * This is needed at write time as quota can be disabled and then enabled -- 2.6.1 -- 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