Btrfs: groundwork for subvolume and snapshot roots
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b9301a5..b557bdd 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4,9 +4,11 @@
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#include <linux/swap.h>
+#include <linux/radix-tree.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
+#include "btrfs_inode.h"
static int check_tree_block(struct btrfs_root *root, struct buffer_head *buf)
{
@@ -180,7 +182,7 @@
static int btree_writepage(struct page *page, struct writeback_control *wbc)
{
struct buffer_head *bh;
- struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb);
+ struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
struct buffer_head *head;
if (!page_has_buffers(page)) {
create_empty_buffers(page, root->fs_info->sb->s_blocksize,
@@ -259,10 +261,13 @@
u64 objectid)
{
root->node = NULL;
+ root->inode = NULL;
root->commit_root = NULL;
root->blocksize = blocksize;
root->ref_cows = 0;
root->fs_info = fs_info;
+ root->objectid = objectid;
+ root->last_trans = 0;
memset(&root->root_key, 0, sizeof(root->root_key));
memset(&root->root_item, 0, sizeof(root->root_item));
return 0;
@@ -287,10 +292,78 @@
return 0;
}
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
+ struct btrfs_key *location)
+{
+ struct btrfs_root *root;
+ struct btrfs_root *tree_root = fs_info->tree_root;
+ struct btrfs_path *path;
+ struct btrfs_leaf *l;
+ int ret = 0;
+
+printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
+ root = kmalloc(sizeof(*root), GFP_NOFS);
+ if (!root) {
+printk("failed1\n");
+ return ERR_PTR(-ENOMEM);
+ }
+ if (location->offset == (u64)-1) {
+ ret = find_and_setup_root(fs_info->sb->s_blocksize,
+ fs_info->tree_root, fs_info,
+ location->objectid, root);
+ if (ret) {
+printk("failed2\n");
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+ goto insert;
+ }
+
+ __setup_root(fs_info->sb->s_blocksize, root, fs_info,
+ location->objectid);
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
+ if (ret != 0) {
+printk("internal search_slot gives us %d\n", ret);
+ if (ret > 0)
+ ret = -ENOENT;
+ goto out;
+ }
+ l = btrfs_buffer_leaf(path->nodes[0]);
+ memcpy(&root->root_item,
+ btrfs_item_ptr(l, path->slots[0], struct btrfs_root_item),
+ sizeof(root->root_item));
+ memcpy(&root->root_key, location, sizeof(*location));
+ ret = 0;
+out:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ if (ret) {
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+ root->node = read_tree_block(root,
+ btrfs_root_blocknr(&root->root_item));
+ BUG_ON(!root->node);
+insert:
+printk("inserting %p\n", root);
+ root->ref_cows = 1;
+ ret = radix_tree_insert(&fs_info->fs_roots_radix, (unsigned long)root,
+ root);
+ if (ret) {
+printk("radix_tree_insert gives us %d\n", ret);
+ brelse(root->node);
+ kfree(root);
+ return ERR_PTR(ret);
+ }
+printk("all worked\n");
+ return root;
+}
+
struct btrfs_root *open_ctree(struct super_block *sb)
{
- struct btrfs_root *root = kmalloc(sizeof(struct btrfs_root),
- GFP_NOFS);
struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
GFP_NOFS);
struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
@@ -304,9 +377,9 @@
init_bit_radix(&fs_info->pinned_radix);
init_bit_radix(&fs_info->pending_del_radix);
+ INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
sb_set_blocksize(sb, 4096);
fs_info->running_transaction = NULL;
- fs_info->fs_root = root;
fs_info->tree_root = tree_root;
fs_info->extent_root = extent_root;
fs_info->inode_root = inode_root;
@@ -318,6 +391,9 @@
fs_info->btree_inode->i_nlink = 1;
fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size;
fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
+ BTRFS_I(fs_info->btree_inode)->root = tree_root;
+ memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
+ sizeof(struct btrfs_key));
insert_inode_hash(fs_info->btree_inode);
mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
@@ -337,13 +413,12 @@
BTRFS_SUPER_INFO_OFFSET /
sb->s_blocksize);
- if (!fs_info->sb_buffer) {
+ if (!fs_info->sb_buffer)
return NULL;
- }
disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data;
- if (!btrfs_super_root(disk_super)) {
+ if (!btrfs_super_root(disk_super))
return NULL;
- }
+
fs_info->disk_super = disk_super;
tree_root->node = read_tree_block(tree_root,
btrfs_super_root(disk_super));
@@ -358,14 +433,8 @@
BTRFS_INODE_MAP_OBJECTID, inode_root);
BUG_ON(ret);
- ret = find_and_setup_root(sb->s_blocksize, tree_root, fs_info,
- BTRFS_FS_TREE_OBJECTID, root);
- BUG_ON(ret);
- root->commit_root = root->node;
- get_bh(root->node);
- root->ref_cows = 1;
- root->fs_info->generation = root->root_key.offset + 1;
- ret = btrfs_find_highest_inode(root, &root->fs_info->last_inode_alloc);
+ fs_info->generation = btrfs_super_generation(disk_super) + 1;
+ ret = btrfs_find_highest_inode(tree_root, &fs_info->last_inode_alloc);
if (ret == 0)
fs_info->highest_inode = fs_info->last_inode_alloc;
memset(&fs_info->kobj, 0, sizeof(fs_info->kobj));
@@ -373,7 +442,7 @@
kobject_set_name(&fs_info->kobj, "%s", sb->s_id);
kobject_register(&fs_info->kobj);
mutex_unlock(&fs_info->fs_mutex);
- return root;
+ return tree_root;
}
int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
@@ -398,12 +467,42 @@
return 0;
}
+int del_fs_roots(struct btrfs_fs_info *fs_info)
+{
+ int ret;
+ struct btrfs_root *gang[8];
+ int i;
+
+ while(1) {
+ ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
+ (void **)gang, 0,
+ ARRAY_SIZE(gang));
+ if (!ret)
+ break;
+ for (i = 0; i < ret; i++) {
+ radix_tree_delete(&fs_info->fs_roots_radix,
+ (unsigned long)gang[i]);
+ if (gang[i]->inode)
+ iput(gang[i]->inode);
+ else
+ printk("no inode for root %p\n", gang[i]);
+ if (gang[i]->node)
+ brelse(gang[i]->node);
+ if (gang[i]->commit_root)
+ brelse(gang[i]->commit_root);
+ kfree(gang[i]);
+ }
+ }
+ return 0;
+}
+
int close_ctree(struct btrfs_root *root)
{
int ret;
struct btrfs_trans_handle *trans;
+ struct btrfs_fs_info *fs_info = root->fs_info;
- mutex_lock(&root->fs_info->fs_mutex);
+ mutex_lock(&fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_commit_transaction(trans, root);
/* run commit again to drop the original snapshot */
@@ -412,29 +511,26 @@
ret = btrfs_write_and_wait_transaction(NULL, root);
BUG_ON(ret);
write_ctree_super(NULL, root);
- mutex_unlock(&root->fs_info->fs_mutex);
+ mutex_unlock(&fs_info->fs_mutex);
- if (root->node)
- btrfs_block_release(root, root->node);
- if (root->fs_info->extent_root->node)
- btrfs_block_release(root->fs_info->extent_root,
- root->fs_info->extent_root->node);
- if (root->fs_info->inode_root->node)
- btrfs_block_release(root->fs_info->inode_root,
- root->fs_info->inode_root->node);
- if (root->fs_info->tree_root->node)
- btrfs_block_release(root->fs_info->tree_root,
- root->fs_info->tree_root->node);
- btrfs_block_release(root, root->commit_root);
- btrfs_block_release(root, root->fs_info->sb_buffer);
- crypto_free_hash(root->fs_info->hash_tfm);
- truncate_inode_pages(root->fs_info->btree_inode->i_mapping, 0);
- iput(root->fs_info->btree_inode);
- kfree(root->fs_info->extent_root);
- kfree(root->fs_info->inode_root);
- kfree(root->fs_info->tree_root);
- kobject_unregister(&root->fs_info->kobj);
- kfree(root);
+ if (fs_info->extent_root->node)
+ btrfs_block_release(fs_info->extent_root,
+ fs_info->extent_root->node);
+ if (fs_info->inode_root->node)
+ btrfs_block_release(fs_info->inode_root,
+ fs_info->inode_root->node);
+ if (fs_info->tree_root->node)
+ btrfs_block_release(fs_info->tree_root,
+ fs_info->tree_root->node);
+ btrfs_block_release(root, fs_info->sb_buffer);
+ crypto_free_hash(fs_info->hash_tfm);
+ truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
+ iput(fs_info->btree_inode);
+ del_fs_roots(fs_info);
+ kfree(fs_info->extent_root);
+ kfree(fs_info->inode_root);
+ kfree(fs_info->tree_root);
+ kobject_unregister(&fs_info->kobj);
return 0;
}
