Commit 6407bf6d authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse

Btrfs: reference counts on data extents

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent dee26a9f
...@@ -8,7 +8,10 @@ ...@@ -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; ...@@ -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 ...@@ -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 ...@@ -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 ...@@ -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 ...@@ -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, ...@@ -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++) {
blocknr = btrfs_node_blockptr(buf_node, i); if (leaf) {
inc_block_ref(trans, root, blocknr); 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);
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, ...@@ -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 ...@@ -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 ...@@ -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 ...@@ -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, ...@@ -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 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock, ...@@ -700,7 +700,7 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock,
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, ...@@ -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 = { ...@@ -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 = {
......
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