void fsw_dnode_release(struct fsw_dnode *dno)
{
struct fsw_volume *vol = dno->vol;
struct fsw_dnode *parent_dno;
dno->refcount--;
if (dno->refcount == 0) {
parent_dno = dno->parent;
// de-register from volume's list
if (dno->next)
dno->next->prev = dno->prev;
if (dno->prev)
dno->prev->next = dno->next;
if (vol->dnode_head == dno)
vol->dnode_head = dno->next;
// run fstype-specific cleanup
vol->fstype_table->dnode_free(vol, dno);
fsw_strfree(&dno->name);
fsw_free(dno);
// release our pointer to the parent, possibly deallocating it, too
if (parent_dno)
fsw_dnode_release(parent_dno);
}
}
void fsw_unmount(struct fsw_volume *vol)
{
if (vol->root)
fsw_dnode_release(vol->root);
/// @todo check that no other dnodes are still around
vol->fstype_table->volume_free(vol);
fsw_blockcache_free(vol);
fsw_strfree(&vol->label);
fsw_free(vol);
}
fsw_status_t fsw_dnode_resolve(struct fsw_dnode *dno, struct fsw_dnode **target_dno_out)
{
fsw_status_t status;
struct fsw_string target_name;
struct fsw_dnode *target_dno;
/* Linux kernel max link count is 40 */
int link_count = 40;
fsw_dnode_retain(dno);
while (--link_count > 0) {
// get full information
status = fsw_dnode_fill(dno);
if (status)
goto errorexit;
if (dno->type != FSW_DNODE_TYPE_SYMLINK) {
// found a non-symlink target, return it
*target_dno_out = dno;
return FSW_SUCCESS;
}
if (dno->parent == NULL) { // safety measure, cannot happen in theory
status = FSW_NOT_FOUND;
goto errorexit;
}
// read the link's target
status = fsw_dnode_readlink(dno, &target_name);
if (status)
goto errorexit;
// resolve it
status = fsw_dnode_lookup_path(dno->parent, &target_name, '/', &target_dno);
fsw_strfree(&target_name);
if (status)
goto errorexit;
// target_dno becomes the new dno
fsw_dnode_release(dno);
dno = target_dno; // is already retained
}
if(link_count == 0)
status = FSW_NOT_FOUND;
errorexit:
fsw_dnode_release(dno);
return status;
}