+/*
+ * get the struct segment_info from seg_list
+ * for the given name.
+ * down_read(&dcssblk_devices_sem) must be held.
+ */
+static struct segment_info *
+dcssblk_get_segment_by_name(char *name)
+{
+ struct dcssblk_dev_info *dev_info;
+ struct segment_info *entry;
+
+ list_for_each_entry(dev_info, &dcssblk_devices, lh) {
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ if (!strcmp(name, entry->segment_name))
+ return entry;
+ }
+ }
+ return NULL;
+}
+
+/*
+ * get the highest address of the multi-segment block.
+ */
+static unsigned long
+dcssblk_find_highest_addr(struct dcssblk_dev_info *dev_info)
+{
+ unsigned long highest_addr;
+ struct segment_info *entry;
+
+ highest_addr = 0;
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ if (highest_addr < entry->end)
+ highest_addr = entry->end;
+ }
+ return highest_addr;
+}
+
+/*
+ * get the lowest address of the multi-segment block.
+ */
+static unsigned long
+dcssblk_find_lowest_addr(struct dcssblk_dev_info *dev_info)
+{
+ int set_first;
+ unsigned long lowest_addr;
+ struct segment_info *entry;
+
+ set_first = 0;
+ lowest_addr = 0;
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ if (set_first == 0) {
+ lowest_addr = entry->start;
+ set_first = 1;
+ } else {
+ if (lowest_addr > entry->start)
+ lowest_addr = entry->start;
+ }
+ }
+ return lowest_addr;
+}
+
+/*
+ * Check continuity of segments.
+ */
+static int
+dcssblk_is_continuous(struct dcssblk_dev_info *dev_info)
+{
+ int i, j, rc;
+ struct segment_info *sort_list, *entry, temp;
+
+ if (dev_info->num_of_segments <= 1)
+ return 0;
+
+ sort_list = kzalloc(
+ sizeof(struct segment_info) * dev_info->num_of_segments,
+ GFP_KERNEL);
+ if (sort_list == NULL)
+ return -ENOMEM;
+ i = 0;
+ list_for_each_entry(entry, &dev_info->seg_list, lh) {
+ memcpy(&sort_list[i], entry, sizeof(struct segment_info));
+ i++;
+ }
+
+ /* sort segments */
+ for (i = 0; i < dev_info->num_of_segments; i++)
+ for (j = 0; j < dev_info->num_of_segments; j++)
+ if (sort_list[j].start > sort_list[i].start) {
+ memcpy(&temp, &sort_list[i],
+ sizeof(struct segment_info));
+ memcpy(&sort_list[i], &sort_list[j],
+ sizeof(struct segment_info));
+ memcpy(&sort_list[j], &temp,
+ sizeof(struct segment_info));
+ }
+
+ /* check continuity */
+ for (i = 0; i < dev_info->num_of_segments - 1; i++) {
+ if ((sort_list[i].end + 1) != sort_list[i+1].start) {
+ PRINT_ERR("Segment %s is not contiguous with "
+ "segment %s\n",
+ sort_list[i].segment_name,
+ sort_list[i+1].segment_name);
+ rc = -EINVAL;
+ goto out;
+ }
+ /* EN and EW are allowed in a block device */
+ if (sort_list[i].segment_type != sort_list[i+1].segment_type) {
+ if (!(sort_list[i].segment_type & SEGMENT_EXCLUSIVE) ||
+ (sort_list[i].segment_type == SEG_TYPE_ER) ||
+ !(sort_list[i+1].segment_type &
+ SEGMENT_EXCLUSIVE) ||
+ (sort_list[i+1].segment_type == SEG_TYPE_ER)) {
+ PRINT_ERR("Segment %s has different type from "
+ "segment %s\n",
+ sort_list[i].segment_name,
+ sort_list[i+1].segment_name);
+ rc = -EINVAL;
+ goto out;
+ }
+ }
+ }
+ rc = 0;
+out:
+ kfree(sort_list);
+ return rc;
+}
+
+/*
+ * Load a segment
+ */
+static int
+dcssblk_load_segment(char *name, struct segment_info **seg_info)
+{
+ int rc;
+
+ /* already loaded? */
+ down_read(&dcssblk_devices_sem);
+ *seg_info = dcssblk_get_segment_by_name(name);
+ up_read(&dcssblk_devices_sem);
+ if (*seg_info != NULL)
+ return -EEXIST;
+
+ /* get a struct segment_info */
+ *seg_info = kzalloc(sizeof(struct segment_info), GFP_KERNEL);
+ if (*seg_info == NULL)
+ return -ENOMEM;
+
+ strcpy((*seg_info)->segment_name, name);
+
+ /* load the segment */
+ rc = segment_load(name, SEGMENT_SHARED,
+ &(*seg_info)->start, &(*seg_info)->end);
+ if (rc < 0) {
+ segment_warning(rc, (*seg_info)->segment_name);
+ kfree(*seg_info);
+ } else {
+ INIT_LIST_HEAD(&(*seg_info)->lh);
+ (*seg_info)->segment_type = rc;
+ }
+ return rc;
+}
+