int
get_bmap_ext(
xfs_agnumber_t agno,
xfs_agblock_t agbno,
xfs_agblock_t maxbno,
xfs_extlen_t *blen)
{
int *statep;
unsigned long key;
statep = btree_find(ag_bmap[agno], agbno, &key);
if (!statep)
return -1;
if (key == agbno) {
if (blen) {
if (!btree_peek_next(ag_bmap[agno], &key))
return -1;
*blen = MIN(maxbno, key) - agbno;
}
return *statep;
}
statep = btree_peek_prev(ag_bmap[agno], NULL);
if (!statep)
return -1;
if (blen)
*blen = MIN(maxbno, key) - agbno;
return *statep;
}
int
search_dup_extent(
xfs_agnumber_t agno,
xfs_agblock_t start_agbno,
xfs_agblock_t end_agbno)
{
unsigned long bno;
int ret;
pthread_mutex_lock(&dup_extent_tree_locks[agno]);
if (!btree_find(dup_extent_trees[agno], start_agbno, &bno)) {
ret = 0;
goto out; /* this really shouldn't happen */
}
if (bno < end_agbno) {
ret = 1;
goto out;
}
ret = (uintptr_t)btree_peek_prev(dup_extent_trees[agno], NULL) >
start_agbno;
out:
pthread_mutex_unlock(&dup_extent_tree_locks[agno]);
return ret;
}
static void
update_bmap(
struct btree_root *bmap,
unsigned long offset,
xfs_extlen_t blen,
void *new_state)
{
unsigned long end = offset + blen;
int *cur_state;
unsigned long cur_key;
int *next_state;
unsigned long next_key;
int *prev_state;
cur_state = btree_find(bmap, offset, &cur_key);
if (!cur_state)
return;
if (offset == cur_key) {
/* if the start is the same as the "item" extent */
if (cur_state == new_state)
return;
/*
* Note: this may be NULL if we are updating the map for
* the superblock.
*/
prev_state = btree_peek_prev(bmap, NULL);
next_state = btree_peek_next(bmap, &next_key);
if (next_key > end) {
/* different end */
if (new_state == prev_state) {
/* #1: prev has same state, move offset up */
btree_update_key(bmap, offset, end);
return;
}
/* #4: insert new extent after, update current value */
btree_update_value(bmap, offset, new_state);
btree_insert(bmap, end, cur_state);
return;
}
/* same end (and same start) */
if (new_state == next_state) {
/* next has same state */
if (new_state == prev_state) {
/* #3: merge prev & next */
btree_delete(bmap, offset);
btree_delete(bmap, end);
return;
}
/* #8: merge next */
btree_update_value(bmap, offset, new_state);
btree_delete(bmap, end);
return;
}
/* same start, same end, next has different state */
if (new_state == prev_state) {
/* #5: prev has same state */
btree_delete(bmap, offset);
return;
}
/* #6: update value only */
btree_update_value(bmap, offset, new_state);
return;
}
/* different start, offset is in the middle of "cur" */
prev_state = btree_peek_prev(bmap, NULL);
ASSERT(prev_state != NULL);
if (prev_state == new_state)
return;
if (end == cur_key) {
/* end is at the same point as the current extent */
if (new_state == cur_state) {
/* #7: move next extent down */
btree_update_key(bmap, end, offset);
return;
}
/* #9: different start, same end, add new extent */
btree_insert(bmap, offset, new_state);
return;
}
/* #2: insert an extent into the middle of another extent */
btree_insert(bmap, offset, new_state);
btree_insert(bmap, end, prev_state);
}
