#include "disk-io.h"
#include "print-tree.h"
+static int find_free_extent(struct btrfs_root *orig_root, u64 num_blocks,
+ u64 search_start, u64 search_end,
+ struct btrfs_key *ins);
+static int finish_current_insert(struct btrfs_root *extent_root);
+static int run_pending(struct btrfs_root *extent_root);
+
/*
* pending extents are blocks that we're trying to allocate in the extent
* map while trying to grow the map because of other allocations. To avoid
* other allocations are done. The pending tag is also used in the same
* manner for deletes.
*/
-#define CTREE_EXTENT_PENDING 0
+#define CTREE_EXTENT_PENDING_DEL 0
+
+static int inc_block_ref(struct btrfs_root *root, u64 blocknr)
+{
+ struct btrfs_path path;
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_leaf *l;
+ struct btrfs_extent_item *item;
+ struct btrfs_key ins;
+ u32 refs;
+
+ find_free_extent(root->extent_root, 0, 0, (u64)-1, &ins);
+ btrfs_init_path(&path);
+ key.objectid = blocknr;
+ key.flags = 0;
+ key.offset = 1;
+ ret = btrfs_search_slot(root->extent_root, &key, &path, 0, 1);
+ if (ret != 0)
+ BUG();
+ BUG_ON(ret != 0);
+ l = &path.nodes[0]->leaf;
+ item = (struct btrfs_extent_item *)(l->data +
+ btrfs_item_offset(l->items +
+ path.slots[0]));
+ refs = btrfs_extent_refs(item);
+ btrfs_set_extent_refs(item, refs + 1);
+
+ BUG_ON(list_empty(&path.nodes[0]->dirty));
+ btrfs_release_path(root->extent_root, &path);
+ finish_current_insert(root->extent_root);
+ run_pending(root->extent_root);
+ return 0;
+}
+
+static int lookup_block_ref(struct btrfs_root *root, u64 blocknr, u32 *refs)
+{
+ struct btrfs_path path;
+ int ret;
+ struct btrfs_key key;
+ struct btrfs_leaf *l;
+ struct btrfs_extent_item *item;
+ btrfs_init_path(&path);
+ key.objectid = blocknr;
+ key.flags = 0;
+ key.offset = 1;
+ ret = btrfs_search_slot(root->extent_root, &key, &path, 0, 0);
+ if (ret != 0)
+ BUG();
+ l = &path.nodes[0]->leaf;
+ item = (struct btrfs_extent_item *)(l->data +
+ btrfs_item_offset(l->items +
+ path.slots[0]));
+ *refs = btrfs_extent_refs(item);
+ btrfs_release_path(root->extent_root, &path);
+ return 0;
+}
+
+int btrfs_inc_ref(struct btrfs_root *root, struct btrfs_buffer *buf)
+{
+ u64 blocknr;
+ int i;
+
+ if (root == root->extent_root)
+ return 0;
+ if (btrfs_is_leaf(&buf->node))
+ return 0;
+
+ for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) {
+ blocknr = btrfs_node_blockptr(&buf->node, i);
+ inc_block_ref(root, blocknr);
+ }
+ return 0;
+}
+
+int btrfs_finish_extent_commit(struct btrfs_root *root)
+{
+ struct btrfs_root *extent_root = root->extent_root;
+ unsigned long gang[8];
+ int ret;
+ int i;
+
+ while(1) {
+ ret = radix_tree_gang_lookup(&extent_root->pinned_radix,
+ (void **)gang, 0,
+ ARRAY_SIZE(gang));
+ if (!ret)
+ break;
+ for (i = 0; i < ret; i++) {
+ radix_tree_delete(&extent_root->pinned_radix, gang[i]);
+ }
+ }
+ extent_root->last_insert.objectid = 0;
+ extent_root->last_insert.offset = 0;
+ return 0;
+}
+
+static int finish_current_insert(struct btrfs_root *extent_root)
+{
+ struct btrfs_key ins;
+ struct btrfs_extent_item extent_item;
+ int i;
+ int ret;
+
+ btrfs_set_extent_refs(&extent_item, 1);
+ btrfs_set_extent_owner(&extent_item,
+ btrfs_header_parentid(&extent_root->node->node.header));
+ ins.offset = 1;
+ ins.flags = 0;
+
+ for (i = 0; i < extent_root->current_insert.flags; i++) {
+ ins.objectid = extent_root->current_insert.objectid + i;
+ ret = btrfs_insert_item(extent_root, &ins, &extent_item,
+ sizeof(extent_item));
+ BUG_ON(ret);
+ }
+ extent_root->current_insert.offset = 0;
+ return 0;
+}
+
+/*
+ * remove an extent from the root, returns 0 on success
+ */
+static int __free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks)
+{
+ struct btrfs_path path;
+ struct btrfs_key key;
+ struct btrfs_root *extent_root = root->extent_root;
+ int ret;
+ struct btrfs_item *item;
+ struct btrfs_extent_item *ei;
+ struct btrfs_key ins;
+ u32 refs;
+
+ key.objectid = blocknr;
+ key.flags = 0;
+ key.offset = num_blocks;
+
+ find_free_extent(root, 0, 0, (u64)-1, &ins);
+ btrfs_init_path(&path);
+ ret = btrfs_search_slot(extent_root, &key, &path, -1, 1);
+ if (ret) {
+ printf("failed to find %Lu\n", key.objectid);
+ btrfs_print_tree(extent_root, extent_root->node);
+ printf("failed to find %Lu\n", key.objectid);
+ BUG();
+ }
+ item = path.nodes[0]->leaf.items + path.slots[0];
+ ei = (struct btrfs_extent_item *)(path.nodes[0]->leaf.data +
+ btrfs_item_offset(item));
+ BUG_ON(ei->refs == 0);
+ refs = btrfs_extent_refs(ei) - 1;
+ btrfs_set_extent_refs(ei, refs);
+ if (refs == 0) {
+ if (root == extent_root) {
+ int err;
+ radix_tree_preload(GFP_KERNEL);
+ err = radix_tree_insert(&extent_root->pinned_radix,
+ blocknr, (void *)blocknr);
+ BUG_ON(err);
+ radix_tree_preload_end();
+ }
+ ret = btrfs_del_item(extent_root, &path);
+ if (root != extent_root &&
+ extent_root->last_insert.objectid < blocknr)
+ extent_root->last_insert.objectid = blocknr;
+ if (ret)
+ BUG();
+ }
+ btrfs_release_path(extent_root, &path);
+ finish_current_insert(extent_root);
+ return ret;
+}
/*
* find all the blocks marked as pending in the radix tree and remove
* them from the extent map
*/
-static int del_pending_extents(struct ctree_root *extent_root)
+static int del_pending_extents(struct btrfs_root *extent_root)
{
int ret;
- struct key key;
- struct tree_buffer *gang[4];
+ struct btrfs_buffer *gang[4];
int i;
- struct ctree_path path;
while(1) {
ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix,
(void **)gang, 0,
ARRAY_SIZE(gang),
- CTREE_EXTENT_PENDING);
+ CTREE_EXTENT_PENDING_DEL);
if (!ret)
break;
for (i = 0; i < ret; i++) {
- key.objectid = gang[i]->blocknr;
- key.flags = 0;
- key.offset = 1;
- init_path(&path);
- ret = search_slot(extent_root, &key, &path, -1);
- if (ret) {
- print_tree(extent_root, extent_root->node);
- printf("unable to find %Lu\n", key.objectid);
- BUG();
- // FIXME undo it and return sane
- return ret;
- }
- ret = del_item(extent_root, &path);
- if (ret) {
- BUG();
- return ret;
- }
- release_path(extent_root, &path);
+ ret = __free_extent(extent_root, gang[i]->blocknr, 1);
radix_tree_tag_clear(&extent_root->cache_radix,
gang[i]->blocknr,
- CTREE_EXTENT_PENDING);
- tree_block_release(extent_root, gang[i]);
+ CTREE_EXTENT_PENDING_DEL);
+ btrfs_block_release(extent_root, gang[i]);
}
}
return 0;
}
+static int run_pending(struct btrfs_root *extent_root)
+{
+ while(radix_tree_tagged(&extent_root->cache_radix,
+ CTREE_EXTENT_PENDING_DEL))
+ del_pending_extents(extent_root);
+ return 0;
+}
+
+
/*
* remove an extent from the root, returns 0 on success
*/
-int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
+int btrfs_free_extent(struct btrfs_root *root, u64 blocknr, u64 num_blocks)
{
- struct ctree_path path;
- struct key key;
- struct ctree_root *extent_root = root->extent_root;
- struct tree_buffer *t;
+ struct btrfs_key key;
+ struct btrfs_root *extent_root = root->extent_root;
+ struct btrfs_buffer *t;
int pending_ret;
int ret;
- key.objectid = blocknr;
- key.flags = 0;
- key.offset = num_blocks;
+
if (root == extent_root) {
- t = read_tree_block(root, key.objectid);
- radix_tree_tag_set(&root->cache_radix, key.objectid,
- CTREE_EXTENT_PENDING);
+ t = find_tree_block(root, blocknr);
+ radix_tree_tag_set(&root->cache_radix, blocknr,
+ CTREE_EXTENT_PENDING_DEL);
return 0;
}
- init_path(&path);
- ret = search_slot(extent_root, &key, &path, -1);
- if (ret) {
- print_tree(extent_root, extent_root->node);
- printf("failed to find %Lu\n", key.objectid);
- BUG();
- }
- ret = del_item(extent_root, &path);
- if (ret)
- BUG();
- release_path(extent_root, &path);
- pending_ret = del_pending_extents(root->extent_root);
+ key.objectid = blocknr;
+ key.flags = 0;
+ key.offset = num_blocks;
+ ret = __free_extent(root, blocknr, num_blocks);
+ pending_ret = run_pending(root->extent_root);
return ret ? ret : pending_ret;
}
* ins->offset == number of blocks
* Any available blocks before search_start are skipped.
*/
-static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
- u64 search_start, u64 search_end, struct key *ins)
+static int find_free_extent(struct btrfs_root *orig_root, u64 num_blocks,
+ u64 search_start, u64 search_end,
+ struct btrfs_key *ins)
{
- struct ctree_path path;
- struct key *key;
+ struct btrfs_path path;
+ struct btrfs_key key;
int ret;
u64 hole_size = 0;
int slot = 0;
u64 last_block;
+ u64 test_block;
int start_found;
- struct leaf *l;
- struct ctree_root * root = orig_root->extent_root;
+ struct btrfs_leaf *l;
+ struct btrfs_root * root = orig_root->extent_root;
+ int total_needed = num_blocks;
+ total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3;
+ if (root->last_insert.objectid > search_start)
+ search_start = root->last_insert.objectid;
check_failed:
- init_path(&path);
+ btrfs_init_path(&path);
ins->objectid = search_start;
ins->offset = 0;
ins->flags = 0;
start_found = 0;
- ret = search_slot(root, ins, &path, 0);
+ ret = btrfs_search_slot(root, ins, &path, 0, 0);
if (ret < 0)
goto error;
+ if (path.slots[0] > 0)
+ path.slots[0]--;
+
while (1) {
l = &path.nodes[0]->leaf;
slot = path.slots[0];
- if (slot >= l->header.nritems) {
- ret = next_leaf(root, &path);
+ if (slot >= btrfs_header_nritems(&l->header)) {
+ ret = btrfs_next_leaf(root, &path);
if (ret == 0)
continue;
if (ret < 0)
goto error;
if (!start_found) {
ins->objectid = search_start;
- ins->offset = num_blocks;
+ ins->offset = (u64)-1;
start_found = 1;
goto check_pending;
}
ins->objectid = last_block > search_start ?
last_block : search_start;
- ins->offset = num_blocks;
+ ins->offset = (u64)-1;
goto check_pending;
}
- key = &l->items[slot].key;
- if (key->objectid >= search_start) {
+ btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
+ if (key.objectid >= search_start) {
if (start_found) {
- hole_size = key->objectid - last_block;
- if (hole_size > num_blocks) {
+ if (last_block < search_start)
+ last_block = search_start;
+ hole_size = key.objectid - last_block;
+ if (hole_size > total_needed) {
ins->objectid = last_block;
- ins->offset = num_blocks;
+ ins->offset = hole_size;
goto check_pending;
}
- } else
- start_found = 1;
- last_block = key->objectid + key->offset;
+ }
}
+ start_found = 1;
+ last_block = key.objectid + key.offset;
path.slots[0]++;
}
// FIXME -ENOSPC
/* we have to make sure we didn't find an extent that has already
* been allocated by the map tree or the original allocation
*/
- release_path(root, &path);
+ btrfs_release_path(root, &path);
BUG_ON(ins->objectid < search_start);
- if (orig_root->extent_root == orig_root) {
- BUG_ON(num_blocks != 1);
- if ((root->current_insert.objectid <= ins->objectid &&
- root->current_insert.objectid +
- root->current_insert.offset > ins->objectid) ||
- (root->current_insert.objectid > ins->objectid &&
- root->current_insert.objectid <= ins->objectid +
- ins->offset) ||
- radix_tree_tag_get(&root->cache_radix, ins->objectid,
- CTREE_EXTENT_PENDING)) {
- search_start = ins->objectid + 1;
+ for (test_block = ins->objectid;
+ test_block < ins->objectid + total_needed; test_block++) {
+ if (radix_tree_lookup(&root->pinned_radix, test_block)) {
+ search_start = test_block + 1;
goto check_failed;
}
}
- if (ins->offset != 1)
- BUG();
+ BUG_ON(root->current_insert.offset);
+ root->current_insert.offset = total_needed - num_blocks;
+ root->current_insert.objectid = ins->objectid + num_blocks;
+ root->current_insert.flags = 0;
+ root->last_insert.objectid = ins->objectid;
+ ins->offset = num_blocks;
return 0;
error:
- release_path(root, &path);
+ btrfs_release_path(root, &path);
return ret;
}
-/*
- * insert all of the pending extents reserved during the original
- * allocation. (CTREE_EXTENT_PENDING). Returns zero if it all worked out
- */
-static int insert_pending_extents(struct ctree_root *extent_root)
-{
- int ret;
- struct key key;
- struct extent_item item;
- struct tree_buffer *gang[4];
- int i;
-
- // FIXME -ENOSPC
- item.refs = 1;
- item.owner = extent_root->node->node.header.parentid;
- while(1) {
- ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix,
- (void **)gang, 0,
- ARRAY_SIZE(gang),
- CTREE_EXTENT_PENDING);
- if (!ret)
- break;
- for (i = 0; i < ret; i++) {
- key.objectid = gang[i]->blocknr;
- key.flags = 0;
- key.offset = 1;
- ret = insert_item(extent_root, &key, &item,
- sizeof(item));
- if (ret) {
- BUG();
- // FIXME undo it and return sane
- return ret;
- }
- radix_tree_tag_clear(&extent_root->cache_radix,
- gang[i]->blocknr,
- CTREE_EXTENT_PENDING);
- tree_block_release(extent_root, gang[i]);
- }
- }
- return 0;
-}
-
/*
* finds a free extent and does all the dirty work required for allocation
* returns the key for the extent through ins, and a tree buffer for
*
* returns 0 if everything worked, non-zero otherwise.
*/
-int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
- u64 search_end, u64 owner, struct key *ins,
- struct tree_buffer **buf)
+int alloc_extent(struct btrfs_root *root, u64 num_blocks, u64 search_start,
+ u64 search_end, u64 owner, struct btrfs_key *ins)
{
int ret;
int pending_ret;
- struct extent_item extent_item;
- extent_item.refs = 1;
- extent_item.owner = owner;
+ struct btrfs_root *extent_root = root->extent_root;
+ struct btrfs_extent_item extent_item;
- ret = find_free_extent(root, num_blocks, search_start, search_end, ins);
- if (ret)
- return ret;
- if (root != root->extent_root) {
- memcpy(&root->extent_root->current_insert, ins, sizeof(*ins));
- ret = insert_item(root->extent_root, ins, &extent_item,
- sizeof(extent_item));
- memset(&root->extent_root->current_insert, 0,
- sizeof(struct key));
- pending_ret = insert_pending_extents(root->extent_root);
- if (ret)
- return ret;
- if (pending_ret)
- return pending_ret;
- *buf = find_tree_block(root, ins->objectid);
+ btrfs_set_extent_refs(&extent_item, 1);
+ btrfs_set_extent_owner(&extent_item, owner);
+
+ if (root == extent_root) {
+ BUG_ON(extent_root->current_insert.offset == 0);
+ BUG_ON(num_blocks != 1);
+ BUG_ON(extent_root->current_insert.flags ==
+ extent_root->current_insert.offset);
+ ins->offset = 1;
+ ins->objectid = extent_root->current_insert.objectid +
+ extent_root->current_insert.flags++;
return 0;
}
- /* we're allocating an extent for the extent tree, don't recurse */
- BUG_ON(ins->offset != 1);
- *buf = find_tree_block(root, ins->objectid);
- BUG_ON(!*buf);
- radix_tree_tag_set(&root->cache_radix, ins->objectid,
- CTREE_EXTENT_PENDING);
- (*buf)->count++;
- return 0;
+ ret = find_free_extent(root, num_blocks, search_start,
+ search_end, ins);
+ if (ret)
+ return ret;
+
+ ret = btrfs_insert_item(extent_root, ins, &extent_item,
+ sizeof(extent_item));
+ finish_current_insert(extent_root);
+ pending_ret = run_pending(extent_root);
+ if (ret)
+ return ret;
+ if (pending_ret)
+ return pending_ret;
+ return 0;
}
/*
* helper function to allocate a block for a given tree
* returns the tree buffer or NULL.
*/
-struct tree_buffer *alloc_free_block(struct ctree_root *root)
+struct btrfs_buffer *btrfs_alloc_free_block(struct btrfs_root *root)
{
- struct key ins;
+ struct btrfs_key ins;
int ret;
- struct tree_buffer *buf = NULL;
+ struct btrfs_buffer *buf;
ret = alloc_extent(root, 1, 0, (unsigned long)-1,
- root->node->node.header.parentid,
- &ins, &buf);
-
+ btrfs_header_parentid(&root->node->node.header),
+ &ins);
if (ret) {
BUG();
return NULL;
}
- if (root != root->extent_root)
- BUG_ON(radix_tree_tag_get(&root->extent_root->cache_radix,
- buf->blocknr, CTREE_EXTENT_PENDING));
+ buf = find_tree_block(root, ins.objectid);
+ dirty_tree_block(root, buf);
return buf;
}
+
+int walk_down_tree(struct btrfs_root *root, struct btrfs_path *path, int *level)
+{
+ struct btrfs_buffer *next;
+ struct btrfs_buffer *cur;
+ u64 blocknr;
+ int ret;
+ u32 refs;
+
+ ret = lookup_block_ref(root, path->nodes[*level]->blocknr, &refs);
+ BUG_ON(ret);
+ if (refs > 1)
+ goto out;
+ while(*level > 0) {
+ cur = path->nodes[*level];
+ if (path->slots[*level] >=
+ btrfs_header_nritems(&cur->node.header))
+ break;
+ blocknr = btrfs_node_blockptr(&cur->node, path->slots[*level]);
+ ret = lookup_block_ref(root, blocknr, &refs);
+ if (refs != 1 || *level == 1) {
+ path->slots[*level]++;
+ ret = btrfs_free_extent(root, blocknr, 1);
+ BUG_ON(ret);
+ continue;
+ }
+ BUG_ON(ret);
+ next = read_tree_block(root, blocknr);
+ if (path->nodes[*level-1])
+ btrfs_block_release(root, path->nodes[*level-1]);
+ path->nodes[*level-1] = next;
+ *level = btrfs_header_level(&next->node.header);
+ path->slots[*level] = 0;
+ }
+out:
+ ret = btrfs_free_extent(root, path->nodes[*level]->blocknr, 1);
+ btrfs_block_release(root, path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level += 1;
+ BUG_ON(ret);
+ return 0;
+}
+
+int walk_up_tree(struct btrfs_root *root, struct btrfs_path *path, int *level)
+{
+ int i;
+ int slot;
+ int ret;
+ for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
+ slot = path->slots[i];
+ if (slot <
+ btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
+ path->slots[i]++;
+ *level = i;
+ return 0;
+ } else {
+ ret = btrfs_free_extent(root,
+ path->nodes[*level]->blocknr, 1);
+ btrfs_block_release(root, path->nodes[*level]);
+ path->nodes[*level] = NULL;
+ *level = i + 1;
+ BUG_ON(ret);
+ }
+ }
+ return 1;
+}
+
+int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_buffer *snap)
+{
+ int ret;
+ int level;
+ struct btrfs_path path;
+ int i;
+ int orig_level;
+
+ btrfs_init_path(&path);
+
+ level = btrfs_header_level(&snap->node.header);
+ orig_level = level;
+ path.nodes[level] = snap;
+ path.slots[level] = 0;
+ while(1) {
+ ret = walk_down_tree(root, &path, &level);
+ if (ret > 0)
+ break;
+ ret = walk_up_tree(root, &path, &level);
+ if (ret > 0)
+ break;
+ }
+ for (i = 0; i <= orig_level; i++) {
+ if (path.nodes[i]) {
+ btrfs_block_release(root, path.nodes[i]);
+ }
+ }
+
+ return 0;
+}
projects / linux-2.6-block.git / blobdiff