@@ -718,36 +718,34 @@ ext2_try_to_allocate(struct super_block *sb, int group,
718718}
719719
720720/**
721- * find_next_reservable_window():
722- * find a reservable space within the given range.
723- * It does not allocate the reservation window for now:
724- * alloc_new_reservation() will do the work later.
721+ * find_next_reservable_window - Find a reservable space within the given range.
722+ * @search_head: The list to search.
723+ * @my_rsv: The reservation we're currently using.
724+ * @sb: The super block.
725+ * @start_block: The first block we consider to start the real search from
726+ * @last_block: The maximum block number that our goal reservable space
727+ * could start from.
725728 *
726- * @search_head: the head of the searching list;
727- * This is not necessarily the list head of the whole filesystem
729+ * It does not allocate the reservation window: alloc_new_reservation()
730+ * will do the work later.
728731 *
729- * We have both head and start_block to assist the search
730- * for the reservable space. The list starts from head,
731- * but we will shift to the place where start_block is,
732- * then start from there, when looking for a reservable space.
732+ * We search the given range, rather than the whole reservation double
733+ * linked list, (start_block, last_block) to find a free region that is
734+ * of my size and has not been reserved.
733735 *
734- * @sb: the super block.
736+ * @search_head is not necessarily the list head of the whole filesystem.
737+ * We have both head and @start_block to assist the search for the
738+ * reservable space. The list starts from head, but we will shift to
739+ * the place where start_block is, then start from there, when looking
740+ * for a reservable space.
735741 *
736- * @start_block: the first block we consider to start the real search from
737- *
738- * @last_block:
739- * the maximum block number that our goal reservable space
740- * could start from. This is normally the last block in this
741- * group. The search will end when we found the start of next
742- * possible reservable space is out of this boundary.
743- * This could handle the cross boundary reservation window
744- * request.
745- *
746- * basically we search from the given range, rather than the whole
747- * reservation double linked list, (start_block, last_block)
748- * to find a free region that is of my size and has not
749- * been reserved.
742+ * @last_block is normally the last block in this group. The search will end
743+ * when we found the start of next possible reservable space is out
744+ * of this boundary. This could handle the cross boundary reservation
745+ * window request.
750746 *
747+ * Return: -1 if we could not find a range of sufficient size. If we could,
748+ * return 0 and fill in @my_rsv with the range information.
751749 */
752750static int find_next_reservable_window (
753751 struct ext2_reserve_window_node * search_head ,
@@ -835,41 +833,34 @@ static int find_next_reservable_window(
835833}
836834
837835/**
838- * alloc_new_reservation()--allocate a new reservation window
839- *
840- * To make a new reservation, we search part of the filesystem
841- * reservation list (the list that inside the group). We try to
842- * allocate a new reservation window near the allocation goal,
843- * or the beginning of the group, if there is no goal.
844- *
845- * We first find a reservable space after the goal, then from
846- * there, we check the bitmap for the first free block after
847- * it. If there is no free block until the end of group, then the
848- * whole group is full, we failed. Otherwise, check if the free
849- * block is inside the expected reservable space, if so, we
850- * succeed.
851- * If the first free block is outside the reservable space, then
852- * start from the first free block, we search for next available
853- * space, and go on.
854- *
855- * on succeed, a new reservation will be found and inserted into the list
856- * It contains at least one free block, and it does not overlap with other
857- * reservation windows.
836+ * alloc_new_reservation - Allocate a new reservation window.
837+ * @my_rsv: The reservation we're currently using.
838+ * @grp_goal: The goal block relative to the start of the group.
839+ * @sb: The super block.
840+ * @group: The group we are trying to allocate in.
841+ * @bitmap_bh: The block group block bitmap.
858842 *
859- * failed: we failed to find a reservation window in this group
843+ * To make a new reservation, we search part of the filesystem reservation
844+ * list (the list inside the group). We try to allocate a new
845+ * reservation window near @grp_goal, or the beginning of the
846+ * group, if @grp_goal is negative.
860847 *
861- * @my_rsv: the reservation
848+ * We first find a reservable space after the goal, then from there,
849+ * we check the bitmap for the first free block after it. If there is
850+ * no free block until the end of group, then the whole group is full,
851+ * we failed. Otherwise, check if the free block is inside the expected
852+ * reservable space, if so, we succeed.
862853 *
863- * @grp_goal: The goal (group-relative). It is where the search for a
864- * free reservable space should start from.
865- * if we have a goal(goal >0 ), then start from there,
866- * no goal(goal = -1), we start from the first block
867- * of the group.
854+ * If the first free block is outside the reservable space, then start
855+ * from the first free block, we search for next available space, and
856+ * go on.
868857 *
869- * @sb: the super block
870- * @group: the group we are trying to allocate in
871- * @bitmap_bh: the block group block bitmap
858+ * on succeed, a new reservation will be found and inserted into the
859+ * list. It contains at least one free block, and it does not overlap
860+ * with other reservation windows.
872861 *
862+ * Return: 0 on success, -1 if we failed to find a reservation window
863+ * in this group
873864 */
874865static int alloc_new_reservation (struct ext2_reserve_window_node * my_rsv ,
875866 ext2_grpblk_t grp_goal , struct super_block * sb ,
0 commit comments