/*
* Recursively redirect non-dirty buffers on path to modify leaf.
*
* Redirect order is from root to leaf. Otherwise, blocks of path will
* be allocated by reverse order.
*
* FIXME: We can allocate/copy blocks before change common ancestor
* (before changing common ancestor, changes are not visible for
* reader). With this, we may be able to reduce locking time.
*/
int cursor_redirect(struct cursor *cursor)
{
if(DEBUG_MODE_K==1)
{
printf("\t\t\t\t%25s[K] %25s %4d #in\n",__FILE__,__func__,__LINE__);
}
struct btree *btree = cursor->btree;
struct sb *sb = btree->sb;
int level;
for (level = 0; level <= btree->root.depth; level++) {
struct buffer_head *buffer, *clone;
block_t parent, oldblock, newblock;
struct index_entry *entry;
int redirect, is_leaf = (level == btree->root.depth);
buffer = cursor->path[level].buffer;
/* If buffer needs to redirect to dirty, redirect it */
if (is_leaf)
redirect = leaf_need_redirect(sb, buffer);
else
redirect = bnode_need_redirect(sb, buffer);
/* No need to redirect */
if (!redirect)
continue;
/* Redirect buffer before changing */
clone = new_block(btree);
if (IS_ERR(clone))
return PTR_ERR(clone);
oldblock = bufindex(buffer);
newblock = bufindex(clone);
trace("redirect %Lx to %Lx", oldblock, newblock);
level_redirect_blockput(cursor, level, clone);
if (is_leaf) {
/* This is leaf buffer */
mark_buffer_dirty_atomic(clone);
log_leaf_redirect(sb, oldblock, newblock);
defer_bfree(&sb->defree, oldblock, 1);
} else {
/* This is bnode buffer */
mark_buffer_unify_atomic(clone);
log_bnode_redirect(sb, oldblock, newblock);
defer_bfree(&sb->deunify, oldblock, 1);
}
trace("update parent");
if (!level) {
/* Update pointer in btree->root */
trace("redirect root");
assert(oldblock == btree->root.block);
btree->root.block = newblock;
tux3_mark_btree_dirty(btree);
continue;
}
/* Update entry on parent for the redirected block */
parent = bufindex(cursor->path[level - 1].buffer);
entry = cursor->path[level - 1].next - 1;
entry->block = cpu_to_be64(newblock);
log_bnode_update(sb, parent, newblock, be64_to_cpu(entry->key));
}
cursor_check(cursor);
return 0;
}
int cursor_redirect(struct cursor *cursor)
{
struct btree *btree = cursor->btree;
unsigned level = btree->root.depth;
struct sb *sb = btree->sb;
block_t uninitialized_var(child);
while (1) {
struct buffer_head *buffer;
block_t uninitialized_var(oldblock);
block_t uninitialized_var(newblock);
int redirect, is_leaf = (level == btree->root.depth);
buffer = cursor->path[level].buffer;
/* If buffer needs to redirect to dirty, redirect it */
if (is_leaf)
redirect = leaf_need_redirect(sb, buffer);
else
redirect = bnode_need_redirect(sb, buffer);
if (redirect) {
/* Redirect buffer before changing */
struct buffer_head *clone = new_block(btree);
if (IS_ERR(clone))
return PTR_ERR(clone);
oldblock = bufindex(buffer);
newblock = bufindex(clone);
trace("redirect %Lx to %Lx", oldblock, newblock);
level_redirect_blockput(cursor, level, clone);
if (is_leaf) {
/* This is leaf buffer */
mark_buffer_dirty_atomic(clone);
log_leaf_redirect(sb, oldblock, newblock);
defer_bfree(&sb->defree, oldblock, 1);
goto parent_level;
}
/* This is bnode buffer */
mark_buffer_rollup_atomic(clone);
log_bnode_redirect(sb, oldblock, newblock);
defer_bfree(&sb->derollup, oldblock, 1);
} else {
if (is_leaf) {
/* This is leaf buffer */
goto parent_level;
}
}
/* Update entry for the redirected child block */
trace("update parent");
block_t block = bufindex(cursor->path[level].buffer);
struct index_entry *entry = cursor->path[level].next - 1;
entry->block = cpu_to_be64(child);
log_bnode_update(sb, block, child, be64_to_cpu(entry->key));
parent_level:
/* If it is already redirected, ancestor is also redirected */
if (!redirect) {
cursor_check(cursor);
return 0;
}
if (!level--) {
trace("redirect root");
assert(oldblock == btree->root.block);
btree->root.block = newblock;
tux3_mark_btree_dirty(btree);
cursor_check(cursor);
return 0;
}
child = newblock;
}
}
