Btrfs: early extent mapping support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 6b64f49..2177744 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -5,6 +5,8 @@
#include "ctree.h"
#include "disk-io.h"
+static int refill_alloc_extent(struct ctree_root *root);
+
static inline void init_path(struct ctree_path *p)
{
memset(p, 0, sizeof(*p));
@@ -29,7 +31,7 @@
{
unsigned int nr = leaf->header.nritems;
if (nr == 0)
- return ARRAY_SIZE(leaf->data);
+ return sizeof(leaf->data);
return leaf->items[nr-1].offset;
}
@@ -421,7 +423,7 @@
* due to splitting. Once we've done all the splitting required
* do the inserts based on the data in the bal array.
*/
- memset(bal, 0, ARRAY_SIZE(bal));
+ memset(bal, 0, sizeof(bal));
while(t && t->node.header.nritems == NODEPTRS_PER_BLOCK) {
c = &t->node;
if (push_node_left(root, path,
@@ -756,6 +758,7 @@
if (leaf_free_space(leaf) < 0)
BUG();
release_path(root, &path);
+ refill_alloc_extent(root);
return 0;
}
@@ -884,6 +887,135 @@
return 0;
}
+int next_leaf(struct ctree_root *root, struct ctree_path *path)
+{
+ int slot;
+ int level = 1;
+ u64 blocknr;
+ struct tree_buffer *c;
+ struct tree_buffer *next;
+
+ while(level < MAX_LEVEL) {
+ if (!path->nodes[level])
+ return -1;
+ slot = path->slots[level] + 1;
+ c = path->nodes[level];
+ if (slot >= c->node.header.nritems) {
+ level++;
+ continue;
+ }
+ blocknr = c->node.blockptrs[slot];
+ next = read_tree_block(root, blocknr);
+ break;
+ }
+ path->slots[level] = slot;
+ while(1) {
+ level--;
+ c = path->nodes[level];
+ tree_block_release(root, c);
+ path->nodes[level] = next;
+ path->slots[level] = 0;
+ if (!level)
+ break;
+ next = read_tree_block(root, next->node.blockptrs[0]);
+ }
+ return 0;
+}
+
+int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
+ u64 search_end, u64 owner, struct key *ins)
+{
+ struct ctree_path path;
+ struct key *key;
+ int ret;
+ u64 hole_size = 0;
+ int slot = 0;
+ u64 last_block;
+ int start_found = 0;
+ struct leaf *l;
+ struct extent_item extent_item;
+
+ init_path(&path);
+ ins->objectid = search_start;
+ ins->offset = 0;
+ ins->flags = 0;
+
+ ret = search_slot(root, ins, &path);
+ while (1) {
+ l = &path.nodes[0]->leaf;
+ slot = path.slots[0];
+ if (!l) {
+ // FIXME allocate root
+ }
+ if (slot >= l->header.nritems) {
+ ret = next_leaf(root, &path);
+ if (ret == 0)
+ continue;
+ if (!start_found) {
+ ins->objectid = search_start;
+ ins->offset = num_blocks;
+ hole_size = search_end - search_start;
+ goto insert;
+ }
+ ins->objectid = last_block;
+ ins->offset = num_blocks;
+ hole_size = search_end - last_block;
+ goto insert;
+ }
+ key = &l->items[slot].key;
+ if (start_found) {
+ hole_size = key->objectid - last_block;
+ if (hole_size > num_blocks) {
+ ins->objectid = last_block;
+ ins->offset = num_blocks;
+ goto insert;
+ }
+ } else
+ start_found = 1;
+ last_block = key->objectid + key->offset;
+ path.slots[0]++;
+ printf("last block is not %lu\n", last_block);
+ }
+ // FIXME -ENOSPC
+insert:
+ extent_item.refs = 1;
+ extent_item.owner = owner;
+ ret = insert_item(root, ins, &extent_item, sizeof(extent_item));
+ return ret;
+}
+
+static int refill_alloc_extent(struct ctree_root *root)
+{
+ struct alloc_extent *ae = root->alloc_extent;
+ struct key key;
+ int ret;
+ int min_blocks = MAX_LEVEL * 2;
+
+ printf("refill alloc root %p, numused %lu total %lu\n", root, ae->num_used, ae->num_blocks);
+ if (ae->num_blocks > ae->num_used && ae->num_blocks - ae->num_used >
+ min_blocks)
+ return 0;
+ ae = root->reserve_extent;
+ if (ae->num_blocks > ae->num_used) {
+ if (root->alloc_extent->num_blocks == 0) {
+ /* we should swap reserve/alloc_extent when alloc
+ * fills up
+ */
+ BUG();
+ }
+ if (ae->num_blocks - ae->num_used < min_blocks)
+ BUG();
+ return 0;
+ }
+ // FIXME, this recurses
+ ret = alloc_extent(root->extent_root,
+ min_blocks * 2, 0, (unsigned long)-1, 0, &key);
+ ae->blocknr = key.objectid;
+ ae->num_blocks = key.offset;
+ ae->num_used = 0;
+ return ret;
+}
+
void print_leaf(struct leaf *l)
{
int i;
@@ -948,8 +1080,8 @@
/* for testing only */
int next_key(int i, int max_key) {
- return rand() % max_key;
- // return i;
+ // return rand() % max_key;
+ return i;
}
int main() {
@@ -960,7 +1092,7 @@
int i;
int num;
int ret;
- int run_size = 25000;
+ int run_size = 256;
int max_key = 100000000;
int tree_size = 0;
struct ctree_path path;
@@ -980,10 +1112,20 @@
ins.objectid = num;
ins.offset = 0;
ins.flags = 0;
+ printf("insert %d\n", i);
ret = insert_item(root, &ins, buf, strlen(buf));
if (!ret)
tree_size++;
+ printf("done insert %d\n", i);
}
+ printf("root used: %lu\n", root->alloc_extent->num_used);
+ printf("root tree\n");
+ print_tree(root, root->node);
+ printf("map tree\n");
+ printf("map used: %lu\n", root->extent_root->alloc_extent->num_used);
+ print_tree(root->extent_root, root->extent_root->node);
+ exit(1);
+
close_ctree(root);
root = open_ctree("dbfile");
printf("starting search\n");