Btrfs: reference counts on data extents
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
parent
dee26a9f7a
commit
6407bf6d7c
|
@ -8,7 +8,10 @@
|
||||||
* Add block mapping tree (simple dm layer)
|
* Add block mapping tree (simple dm layer)
|
||||||
* Add simple tree locking (semaphore per tree)
|
* Add simple tree locking (semaphore per tree)
|
||||||
* Make allocator smarter
|
* Make allocator smarter
|
||||||
|
* make level a field in header
|
||||||
|
* add a block group to struct inode
|
||||||
* Make directory hashing work on 32 bit
|
* Make directory hashing work on 32 bit
|
||||||
|
* Make sure nobh stuff is working properly for cows
|
||||||
* Do actual block accounting
|
* Do actual block accounting
|
||||||
* Check compat and incompat flags on the inode
|
* Check compat and incompat flags on the inode
|
||||||
* Add virtual filesystems, mountable snapshots
|
* Add virtual filesystems, mountable snapshots
|
||||||
|
|
|
@ -9,10 +9,11 @@ struct btrfs_transaction;
|
||||||
|
|
||||||
#define BTRFS_MAGIC "_BtRfS_M"
|
#define BTRFS_MAGIC "_BtRfS_M"
|
||||||
|
|
||||||
#define BTRFS_ROOT_TREE_OBJECTID 1
|
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
|
||||||
#define BTRFS_EXTENT_TREE_OBJECTID 2
|
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
|
||||||
#define BTRFS_INODE_MAP_OBJECTID 3
|
#define BTRFS_INODE_MAP_OBJECTID 3ULL
|
||||||
#define BTRFS_FS_TREE_OBJECTID 4
|
#define BTRFS_FS_TREE_OBJECTID 4ULL
|
||||||
|
#define BTRFS_FIRST_FREE_OBJECTID 5ULL
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* we can actually store much bigger names, but lets not confuse the rest
|
* we can actually store much bigger names, but lets not confuse the rest
|
||||||
|
|
|
@ -13,7 +13,7 @@ static int del_pending_extents(struct btrfs_trans_handle *trans, struct
|
||||||
btrfs_root *extent_root);
|
btrfs_root *extent_root);
|
||||||
|
|
||||||
static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
|
static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
*root, u64 blocknr)
|
*root, u64 blocknr, u64 num_blocks)
|
||||||
{
|
{
|
||||||
struct btrfs_path path;
|
struct btrfs_path path;
|
||||||
int ret;
|
int ret;
|
||||||
|
@ -29,7 +29,7 @@ static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
key.objectid = blocknr;
|
key.objectid = blocknr;
|
||||||
key.flags = 0;
|
key.flags = 0;
|
||||||
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
|
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
|
||||||
key.offset = 1;
|
key.offset = num_blocks;
|
||||||
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
|
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
|
||||||
0, 1);
|
0, 1);
|
||||||
if (ret != 0)
|
if (ret != 0)
|
||||||
|
@ -48,7 +48,7 @@ static int inc_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
}
|
}
|
||||||
|
|
||||||
static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
|
static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
*root, u64 blocknr, u32 *refs)
|
*root, u64 blocknr, u64 num_blocks, u32 *refs)
|
||||||
{
|
{
|
||||||
struct btrfs_path path;
|
struct btrfs_path path;
|
||||||
int ret;
|
int ret;
|
||||||
|
@ -57,7 +57,7 @@ static int lookup_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
struct btrfs_extent_item *item;
|
struct btrfs_extent_item *item;
|
||||||
btrfs_init_path(&path);
|
btrfs_init_path(&path);
|
||||||
key.objectid = blocknr;
|
key.objectid = blocknr;
|
||||||
key.offset = 1;
|
key.offset = num_blocks;
|
||||||
key.flags = 0;
|
key.flags = 0;
|
||||||
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
|
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
|
||||||
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
|
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, &path,
|
||||||
|
@ -76,17 +76,34 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
|
||||||
{
|
{
|
||||||
u64 blocknr;
|
u64 blocknr;
|
||||||
struct btrfs_node *buf_node;
|
struct btrfs_node *buf_node;
|
||||||
|
struct btrfs_leaf *buf_leaf;
|
||||||
|
struct btrfs_disk_key *key;
|
||||||
|
struct btrfs_file_extent_item *fi;
|
||||||
int i;
|
int i;
|
||||||
|
int leaf;
|
||||||
|
int ret;
|
||||||
|
|
||||||
if (!root->ref_cows)
|
if (!root->ref_cows)
|
||||||
return 0;
|
return 0;
|
||||||
buf_node = btrfs_buffer_node(buf);
|
buf_node = btrfs_buffer_node(buf);
|
||||||
if (btrfs_is_leaf(buf_node))
|
leaf = btrfs_is_leaf(buf_node);
|
||||||
return 0;
|
buf_leaf = btrfs_buffer_leaf(buf);
|
||||||
|
|
||||||
for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) {
|
for (i = 0; i < btrfs_header_nritems(&buf_node->header); i++) {
|
||||||
|
if (leaf) {
|
||||||
|
key = &buf_leaf->items[i].key;
|
||||||
|
if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
|
||||||
|
continue;
|
||||||
|
fi = btrfs_item_ptr(buf_leaf, i,
|
||||||
|
struct btrfs_file_extent_item);
|
||||||
|
ret = inc_block_ref(trans, root,
|
||||||
|
btrfs_file_extent_disk_blocknr(fi),
|
||||||
|
btrfs_file_extent_disk_num_blocks(fi));
|
||||||
|
BUG_ON(ret);
|
||||||
|
} else {
|
||||||
blocknr = btrfs_node_blockptr(buf_node, i);
|
blocknr = btrfs_node_blockptr(buf_node, i);
|
||||||
inc_block_ref(trans, root, blocknr);
|
ret = inc_block_ref(trans, root, blocknr, 1);
|
||||||
|
BUG_ON(ret);
|
||||||
|
}
|
||||||
}
|
}
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
@ -469,6 +486,37 @@ struct buffer_head *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
|
||||||
return buf;
|
return buf;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static int drop_leaf_ref(struct btrfs_trans_handle *trans,
|
||||||
|
struct btrfs_root *root, struct buffer_head *cur)
|
||||||
|
{
|
||||||
|
struct btrfs_disk_key *key;
|
||||||
|
struct btrfs_leaf *leaf;
|
||||||
|
struct btrfs_file_extent_item *fi;
|
||||||
|
int i;
|
||||||
|
int nritems;
|
||||||
|
int ret;
|
||||||
|
|
||||||
|
BUG_ON(!btrfs_is_leaf(btrfs_buffer_node(cur)));
|
||||||
|
leaf = btrfs_buffer_leaf(cur);
|
||||||
|
nritems = btrfs_header_nritems(&leaf->header);
|
||||||
|
for (i = 0; i < nritems; i++) {
|
||||||
|
key = &leaf->items[i].key;
|
||||||
|
if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
|
||||||
|
continue;
|
||||||
|
fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
|
||||||
|
/*
|
||||||
|
* FIXME make sure to insert a trans record that
|
||||||
|
* repeats the snapshot del on crash
|
||||||
|
*/
|
||||||
|
ret = btrfs_free_extent(trans, root,
|
||||||
|
btrfs_file_extent_disk_blocknr(fi),
|
||||||
|
btrfs_file_extent_disk_num_blocks(fi),
|
||||||
|
0);
|
||||||
|
BUG_ON(ret);
|
||||||
|
}
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* helper function for drop_snapshot, this walks down the tree dropping ref
|
* helper function for drop_snapshot, this walks down the tree dropping ref
|
||||||
* counts as it goes.
|
* counts as it goes.
|
||||||
|
@ -483,28 +531,33 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
u32 refs;
|
u32 refs;
|
||||||
|
|
||||||
ret = lookup_block_ref(trans, root, path->nodes[*level]->b_blocknr,
|
ret = lookup_block_ref(trans, root, path->nodes[*level]->b_blocknr,
|
||||||
&refs);
|
1, &refs);
|
||||||
BUG_ON(ret);
|
BUG_ON(ret);
|
||||||
if (refs > 1)
|
if (refs > 1)
|
||||||
goto out;
|
goto out;
|
||||||
/*
|
/*
|
||||||
* walk down to the last node level and free all the leaves
|
* walk down to the last node level and free all the leaves
|
||||||
*/
|
*/
|
||||||
while(*level > 0) {
|
while(*level >= 0) {
|
||||||
cur = path->nodes[*level];
|
cur = path->nodes[*level];
|
||||||
if (path->slots[*level] >=
|
if (path->slots[*level] >=
|
||||||
btrfs_header_nritems(btrfs_buffer_header(cur)))
|
btrfs_header_nritems(btrfs_buffer_header(cur)))
|
||||||
break;
|
break;
|
||||||
|
if (*level == 0) {
|
||||||
|
ret = drop_leaf_ref(trans, root, cur);
|
||||||
|
BUG_ON(ret);
|
||||||
|
break;
|
||||||
|
}
|
||||||
blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur),
|
blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur),
|
||||||
path->slots[*level]);
|
path->slots[*level]);
|
||||||
ret = lookup_block_ref(trans, root, blocknr, &refs);
|
ret = lookup_block_ref(trans, root, blocknr, 1, &refs);
|
||||||
if (refs != 1 || *level == 1) {
|
BUG_ON(ret);
|
||||||
|
if (refs != 1) {
|
||||||
path->slots[*level]++;
|
path->slots[*level]++;
|
||||||
ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
|
ret = btrfs_free_extent(trans, root, blocknr, 1, 1);
|
||||||
BUG_ON(ret);
|
BUG_ON(ret);
|
||||||
continue;
|
continue;
|
||||||
}
|
}
|
||||||
BUG_ON(ret);
|
|
||||||
next = read_tree_block(root, blocknr);
|
next = read_tree_block(root, blocknr);
|
||||||
if (path->nodes[*level-1])
|
if (path->nodes[*level-1])
|
||||||
btrfs_block_release(root, path->nodes[*level-1]);
|
btrfs_block_release(root, path->nodes[*level-1]);
|
||||||
|
@ -513,8 +566,8 @@ static int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
path->slots[*level] = 0;
|
path->slots[*level] = 0;
|
||||||
}
|
}
|
||||||
out:
|
out:
|
||||||
ret = btrfs_free_extent(trans, root, path->nodes[*level]->b_blocknr,
|
ret = btrfs_free_extent(trans, root,
|
||||||
1, 1);
|
path->nodes[*level]->b_blocknr, 1, 1);
|
||||||
btrfs_block_release(root, path->nodes[*level]);
|
btrfs_block_release(root, path->nodes[*level]);
|
||||||
path->nodes[*level] = NULL;
|
path->nodes[*level] = NULL;
|
||||||
*level += 1;
|
*level += 1;
|
||||||
|
@ -544,10 +597,10 @@ static int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root
|
||||||
ret = btrfs_free_extent(trans, root,
|
ret = btrfs_free_extent(trans, root,
|
||||||
path->nodes[*level]->b_blocknr,
|
path->nodes[*level]->b_blocknr,
|
||||||
1, 1);
|
1, 1);
|
||||||
|
BUG_ON(ret);
|
||||||
btrfs_block_release(root, path->nodes[*level]);
|
btrfs_block_release(root, path->nodes[*level]);
|
||||||
path->nodes[*level] = NULL;
|
path->nodes[*level] = NULL;
|
||||||
*level = i + 1;
|
*level = i + 1;
|
||||||
BUG_ON(ret);
|
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
return 1;
|
return 1;
|
||||||
|
|
|
@ -25,6 +25,7 @@ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
|
||||||
if (fs_root->fs_info->last_inode_alloc_dirid == dirid)
|
if (fs_root->fs_info->last_inode_alloc_dirid == dirid)
|
||||||
search_start = fs_root->fs_info->last_inode_alloc;
|
search_start = fs_root->fs_info->last_inode_alloc;
|
||||||
|
|
||||||
|
search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
|
||||||
search_key.objectid = search_start;
|
search_key.objectid = search_start;
|
||||||
search_key.flags = 0;
|
search_key.flags = 0;
|
||||||
btrfs_set_key_type(&search_key, BTRFS_INODE_MAP_ITEM_KEY);
|
btrfs_set_key_type(&search_key, BTRFS_INODE_MAP_ITEM_KEY);
|
||||||
|
|
|
@ -700,7 +700,7 @@ out:
|
||||||
static int btrfs_prepare_write(struct file *file, struct page *page,
|
static int btrfs_prepare_write(struct file *file, struct page *page,
|
||||||
unsigned from, unsigned to)
|
unsigned from, unsigned to)
|
||||||
{
|
{
|
||||||
return block_prepare_write(page, from, to, btrfs_get_block);
|
return nobh_prepare_write(page, from, to, btrfs_get_block);
|
||||||
}
|
}
|
||||||
|
|
||||||
static void btrfs_write_super(struct super_block *sb)
|
static void btrfs_write_super(struct super_block *sb)
|
||||||
|
@ -721,7 +721,7 @@ static int btrfs_readpages(struct file *file, struct address_space *mapping,
|
||||||
|
|
||||||
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
|
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
|
||||||
{
|
{
|
||||||
return block_write_full_page(page, btrfs_get_block, wbc);
|
return nobh_writepage(page, btrfs_get_block, wbc);
|
||||||
}
|
}
|
||||||
|
|
||||||
static int btrfs_get_sb(struct file_system_type *fs_type,
|
static int btrfs_get_sb(struct file_system_type *fs_type,
|
||||||
|
@ -768,7 +768,7 @@ static struct address_space_operations btrfs_aops = {
|
||||||
.writepage = btrfs_writepage,
|
.writepage = btrfs_writepage,
|
||||||
.sync_page = block_sync_page,
|
.sync_page = block_sync_page,
|
||||||
.prepare_write = btrfs_prepare_write,
|
.prepare_write = btrfs_prepare_write,
|
||||||
.commit_write = generic_commit_write,
|
.commit_write = nobh_commit_write,
|
||||||
};
|
};
|
||||||
|
|
||||||
static struct inode_operations btrfs_file_inode_operations = {
|
static struct inode_operations btrfs_file_inode_operations = {
|
||||||
|
|
Loading…
Reference in a new issue