/* find delimiting keys of child
Determine left and right delimiting keys for child pointed to by
@parent_coord.
*/
static void find_child_delimiting_keys(znode * parent /* parent znode, passed
* locked */ ,
const coord_t *parent_coord
/* coord where pointer
* to child is stored
*/ ,
reiser4_key * ld /* where to store left
* delimiting key */ ,
reiser4_key * rd /* where to store right
* delimiting key */ )
{
coord_t neighbor;
assert("nikita-1484", parent != NULL);
assert_rw_locked(&(znode_get_tree(parent)->dk_lock));
coord_dup(&neighbor, parent_coord);
if (neighbor.between == AT_UNIT)
/* imitate item ->lookup() behavior. */
neighbor.between = AFTER_UNIT;
if (coord_set_to_left(&neighbor) == 0)
unit_key_by_coord(&neighbor, ld);
else {
assert("nikita-14851", 0);
*ld = *znode_get_ld_key(parent);
}
coord_dup(&neighbor, parent_coord);
if (neighbor.between == AT_UNIT)
neighbor.between = AFTER_UNIT;
if (coord_set_to_right(&neighbor) == 0)
unit_key_by_coord(&neighbor, rd);
else
*rd = *znode_get_rd_key(parent);
}
/* cde_check ->check() method for compressed directory items
used for debugging, every item should have here the most complete
possible check of the consistency of the item that the inventor can
construct
*/
int reiser4_check_cde(const coord_t * coord /* coord of item to check */,
const char **error /* where to store error message */)
{
int i;
int result;
char *item_start;
char *item_end;
reiser4_key key;
coord_t c;
assert("nikita-1357", coord != NULL);
assert("nikita-1358", error != NULL);
if (!ergo(coord->item_pos != 0,
is_dot_key(item_key_by_coord(coord, &key)))) {
*error = "CDE doesn't start with dot";
return -1;
}
item_start = item_body_by_coord(coord);
item_end = item_start + item_length_by_coord(coord);
coord_dup(&c, coord);
result = 0;
for (i = 0; i < units(coord); ++i) {
directory_entry_format *entry;
if ((char *)(header_at(coord, i) + 1) >
item_end - units(coord) * sizeof *entry) {
*error = "CDE header is out of bounds";
result = -1;
break;
}
entry = entry_at(coord, i);
if ((char *)entry < item_start + sizeof(cde_item_format)) {
*error = "CDE header is too low";
result = -1;
break;
}
if ((char *)(entry + 1) > item_end) {
*error = "CDE header is too high";
result = -1;
break;
}
}
return result;
}
/* this returns max key in the item */
reiser4_key *max_item_key_by_coord(const coord_t * coord /* coord to query */ ,
reiser4_key * key /* result */ )
{
coord_t last;
assert("nikita-338", coord != NULL);
assert("nikita-339", coord->node != NULL);
assert("nikita-340", znode_is_loaded(coord->node));
/* make coord pointing to last item's unit */
coord_dup(&last, coord);
last.unit_pos = coord_num_units(&last) - 1;
assert("vs-1560", coord_is_existing_unit(&last));
max_unit_key_by_coord(&last, key);
return key;
}
/**
* reiser4_replace_extent - replace extent and paste 1 or 2 after it
* @un_extent: coordinate of extent to be overwritten
* @lh: need better comment
* @key: need better comment
* @exts_to_add: data prepared for insertion into tree
* @replace: need better comment
* @flags: need better comment
* @return_insert_position: need better comment
*
* Overwrites one extent, pastes 1 or 2 more ones after overwritten one. If
* @return_inserted_position is 1 - @un_extent and @lh are returned set to
* first of newly inserted units, if it is 0 - @un_extent and @lh are returned
* set to extent which was overwritten.
*/
int reiser4_replace_extent(struct replace_handle *h,
int return_inserted_position)
{
int result;
znode *orig_znode;
/*ON_DEBUG(reiser4_extent orig_ext);*/ /* this is for debugging */
assert("vs-990", coord_is_existing_unit(h->coord));
assert("vs-1375", znode_is_write_locked(h->coord->node));
assert("vs-1426", extent_get_width(&h->overwrite) != 0);
assert("vs-1427", extent_get_width(&h->new_extents[0]) != 0);
assert("vs-1427", ergo(h->nr_new_extents == 2,
extent_get_width(&h->new_extents[1]) != 0));
/* compose structure for paste */
init_new_extent(&h->item, &h->new_extents[0], h->nr_new_extents);
coord_dup(&h->coord_after, h->coord);
init_lh(&h->lh_after);
copy_lh(&h->lh_after, h->lh);
reiser4_tap_init(&h->watch, &h->coord_after, &h->lh_after, ZNODE_WRITE_LOCK);
reiser4_tap_monitor(&h->watch);
ON_DEBUG(h->orig_ext = *extent_by_coord(h->coord));
orig_znode = h->coord->node;
#if REISER4_DEBUG
/* make sure that key is set properly */
unit_key_by_coord(h->coord, &h->tmp);
set_key_offset(&h->tmp,
get_key_offset(&h->tmp) +
extent_get_width(&h->overwrite) * current_blocksize);
assert("vs-1080", keyeq(&h->tmp, &h->paste_key));
#endif
/* set insert point after unit to be replaced */
h->coord->between = AFTER_UNIT;
result = insert_into_item(h->coord, return_inserted_position ? h->lh : NULL,
&h->paste_key, &h->item, h->flags);
if (!result) {
/* now we have to replace the unit after which new units were
inserted. Its position is tracked by @watch */
reiser4_extent *ext;
znode *node;
node = h->coord_after.node;
if (node != orig_znode) {
coord_clear_iplug(&h->coord_after);
result = zload(node);
}
if (likely(!result)) {
ext = extent_by_coord(&h->coord_after);
assert("vs-987", znode_is_loaded(node));
assert("vs-988", !memcmp(ext, &h->orig_ext, sizeof(*ext)));
/* overwrite extent unit */
memcpy(ext, &h->overwrite, sizeof(reiser4_extent));
znode_make_dirty(node);
if (node != orig_znode)
zrelse(node);
if (return_inserted_position == 0) {
/* coord and lh are to be set to overwritten
extent */
assert("vs-1662",
WITH_DATA(node, !memcmp(&h->overwrite,
extent_by_coord(
&h->coord_after),
sizeof(reiser4_extent))));
*h->coord = h->coord_after;
done_lh(h->lh);
copy_lh(h->lh, &h->lh_after);
} else {
/* h->coord and h->lh are to be set to first of
inserted units */
assert("vs-1663",
WITH_DATA(h->coord->node,
!memcmp(&h->new_extents[0],
extent_by_coord(h->coord),
sizeof(reiser4_extent))));
assert("vs-1664", h->lh->node == h->coord->node);
}
}
}
reiser4_tap_done(&h->watch);
return result;
}
