Btrfs: subvolumes
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
parent
2932f3ec94
commit
2619ba1f0f
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@ -8,6 +8,7 @@
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* Check compat and incompat flags on the inode
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* Add virtual filesystems, mountable snapshots
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* Get rid of struct ctree_path, limiting tree levels held at one time
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* EEXIST for dirs instead of hash overflow
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* Release
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* Do real tree locking
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* Add extent mirroring (backup copies of blocks)
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@ -301,6 +301,12 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
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int ret = 0;
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printk("read_fs_root looking for %Lu %Lu %u\n", location->objectid, location->offset, location->flags);
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root = radix_tree_lookup(&fs_info->fs_roots_radix,
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(unsigned long)location->objectid);
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if (root) {
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printk("found %p in cache\n", root);
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return root;
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}
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root = kmalloc(sizeof(*root), GFP_NOFS);
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if (!root) {
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printk("failed1\n");
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@ -349,7 +355,8 @@ out:
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insert:
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printk("inserting %p\n", root);
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root->ref_cows = 1;
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ret = radix_tree_insert(&fs_info->fs_roots_radix, (unsigned long)root,
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ret = radix_tree_insert(&fs_info->fs_roots_radix,
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(unsigned long)root->root_key.objectid,
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root);
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if (ret) {
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printk("radix_tree_insert gives us %d\n", ret);
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@ -460,6 +467,20 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
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return 0;
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}
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static int free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
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{
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radix_tree_delete(&fs_info->fs_roots_radix,
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(unsigned long)root->root_key.objectid);
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if (root->inode)
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iput(root->inode);
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if (root->node)
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brelse(root->node);
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if (root->commit_root)
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brelse(root->commit_root);
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kfree(root);
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return 0;
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}
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int del_fs_roots(struct btrfs_fs_info *fs_info)
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{
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int ret;
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@ -472,19 +493,8 @@ int del_fs_roots(struct btrfs_fs_info *fs_info)
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ARRAY_SIZE(gang));
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if (!ret)
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break;
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for (i = 0; i < ret; i++) {
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radix_tree_delete(&fs_info->fs_roots_radix,
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(unsigned long)gang[i]);
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if (gang[i]->inode)
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iput(gang[i]->inode);
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else
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printk("no inode for root %p\n", gang[i]);
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if (gang[i]->node)
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brelse(gang[i]->node);
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if (gang[i]->commit_root)
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brelse(gang[i]->commit_root);
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kfree(gang[i]);
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}
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for (i = 0; i < ret; i++)
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free_fs_root(fs_info, gang[i]);
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}
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return 0;
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}
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178
fs/btrfs/super.c
178
fs/btrfs/super.c
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@ -495,10 +495,6 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
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return ERR_PTR(-EACCES);
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if (inode->i_state & I_NEW) {
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if (sub_root != root) {
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ret = radix_tree_insert(
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&root->fs_info->fs_roots_radix,
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(unsigned long)sub_root,
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sub_root);
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printk("adding new root for inode %lu root %p (found %p)\n", inode->i_ino, sub_root, BTRFS_I(inode)->root);
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igrab(inode);
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sub_root->inode = inode;
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@ -723,22 +719,19 @@ static int btrfs_write_inode(struct inode *inode, int wait)
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}
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static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
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struct inode *dir, int mode)
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struct btrfs_root *root,
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u64 objectid, int mode)
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{
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struct inode *inode;
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struct btrfs_inode_item inode_item;
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struct btrfs_root *root = BTRFS_I(dir)->root;
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struct btrfs_key *location;
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int ret;
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u64 objectid;
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inode = new_inode(dir->i_sb);
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inode = new_inode(root->fs_info->sb);
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if (!inode)
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return ERR_PTR(-ENOMEM);
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BTRFS_I(inode)->root = BTRFS_I(dir)->root;
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ret = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
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BUG_ON(ret);
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BTRFS_I(inode)->root = root;
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inode->i_uid = current->fsuid;
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inode->i_gid = current->fsgid;
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@ -804,10 +797,18 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
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struct inode *inode;
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int err;
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int drop_inode = 0;
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u64 objectid;
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mutex_lock(&root->fs_info->fs_mutex);
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trans = btrfs_start_transaction(root, 1);
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inode = btrfs_new_inode(trans, dir, mode);
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err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
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if (err) {
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err = -ENOSPC;
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goto out_unlock;
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}
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inode = btrfs_new_inode(trans, root, objectid, mode);
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err = PTR_ERR(inode);
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if (IS_ERR(inode))
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goto out_unlock;
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@ -833,9 +834,9 @@ out_unlock:
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}
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static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
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struct inode *inode, struct inode *dir)
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struct btrfs_root *root,
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u64 objectid, u64 dirid)
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{
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struct btrfs_root *root = BTRFS_I(dir)->root;
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int ret;
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char buf[2];
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struct btrfs_key key;
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@ -843,22 +844,20 @@ static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
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buf[0] = '.';
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buf[1] = '.';
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key.objectid = inode->i_ino;
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key.objectid = objectid;
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key.offset = 0;
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key.flags = 0;
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btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
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ret = btrfs_insert_dir_item(trans, root, buf, 1, inode->i_ino,
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ret = btrfs_insert_dir_item(trans, root, buf, 1, objectid,
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&key, 1);
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if (ret)
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goto error;
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key.objectid = dir->i_ino;
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ret = btrfs_insert_dir_item(trans, root, buf, 2, inode->i_ino,
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key.objectid = dirid;
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ret = btrfs_insert_dir_item(trans, root, buf, 2, objectid,
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&key, 1);
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if (ret)
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goto error;
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inode->i_size = 6;
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ret = btrfs_update_inode(trans, root, inode);
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error:
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return ret;
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}
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@ -870,6 +869,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
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struct btrfs_root *root = BTRFS_I(dir)->root;
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int err = 0;
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int drop_on_err = 0;
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u64 objectid;
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mutex_lock(&root->fs_info->fs_mutex);
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trans = btrfs_start_transaction(root, 1);
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err = PTR_ERR(trans);
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goto out_unlock;
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}
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inode = btrfs_new_inode(trans, dir, S_IFDIR | mode);
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err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
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if (err) {
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err = -ENOSPC;
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goto out_unlock;
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}
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inode = btrfs_new_inode(trans, root, objectid, S_IFDIR | mode);
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if (IS_ERR(inode)) {
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err = PTR_ERR(inode);
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goto out_fail;
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@ -886,7 +893,12 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
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inode->i_op = &btrfs_dir_inode_operations;
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inode->i_fop = &btrfs_dir_file_operations;
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err = btrfs_make_empty_dir(trans, inode, dir);
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err = btrfs_make_empty_dir(trans, root, inode->i_ino, dir->i_ino);
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if (err)
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goto out_fail;
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inode->i_size = 6;
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err = btrfs_update_inode(trans, root, inode);
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if (err)
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goto out_fail;
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err = btrfs_add_link(trans, dentry, inode);
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@ -1666,6 +1678,102 @@ static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
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return retval;
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}
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static int create_subvol(struct btrfs_root *root, char *name, int namelen)
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{
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struct btrfs_trans_handle *trans;
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struct btrfs_key key;
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struct btrfs_root_item root_item;
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struct btrfs_inode_item *inode_item;
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struct buffer_head *subvol;
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struct btrfs_leaf *leaf;
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struct btrfs_root *new_root;
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struct inode *inode;
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int ret;
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u64 objectid;
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u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
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mutex_lock(&root->fs_info->fs_mutex);
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trans = btrfs_start_transaction(root, 1);
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BUG_ON(!trans);
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subvol = btrfs_alloc_free_block(trans, root);
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leaf = btrfs_buffer_leaf(subvol);
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btrfs_set_header_nritems(&leaf->header, 0);
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btrfs_set_header_level(&leaf->header, 0);
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btrfs_set_header_blocknr(&leaf->header, subvol->b_blocknr);
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btrfs_set_header_generation(&leaf->header, trans->transid);
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memcpy(leaf->header.fsid, root->fs_info->disk_super->fsid,
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sizeof(leaf->header.fsid));
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inode_item = &root_item.inode;
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memset(inode_item, 0, sizeof(*inode_item));
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btrfs_set_inode_generation(inode_item, 1);
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btrfs_set_inode_size(inode_item, 3);
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btrfs_set_inode_nlink(inode_item, 1);
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btrfs_set_inode_nblocks(inode_item, 1);
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btrfs_set_inode_mode(inode_item, S_IFDIR | 0755);
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btrfs_set_root_blocknr(&root_item, subvol->b_blocknr);
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btrfs_set_root_refs(&root_item, 1);
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mark_buffer_dirty(subvol);
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brelse(subvol);
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subvol = NULL;
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ret = btrfs_find_free_objectid(trans, root->fs_info->tree_root,
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0, &objectid);
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BUG_ON(ret);
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btrfs_set_root_dirid(&root_item, new_dirid);
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key.objectid = objectid;
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key.offset = 1;
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key.flags = 0;
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btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
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ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
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&root_item);
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BUG_ON(ret);
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/*
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* insert the directory item
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*/
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key.offset = (u64)-1;
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ret = btrfs_insert_dir_item(trans, root->fs_info->tree_root,
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name, namelen,
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root->fs_info->sb->s_root->d_inode->i_ino,
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&key, 0);
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BUG_ON(ret);
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ret = btrfs_commit_transaction(trans, root);
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BUG_ON(ret);
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new_root = btrfs_read_fs_root(root->fs_info, &key);
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BUG_ON(!new_root);
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trans = btrfs_start_transaction(new_root, 1);
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BUG_ON(!trans);
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inode = btrfs_new_inode(trans, new_root, new_dirid, S_IFDIR | 0700);
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inode->i_op = &btrfs_dir_inode_operations;
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inode->i_fop = &btrfs_dir_file_operations;
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ret = btrfs_make_empty_dir(trans, new_root, new_dirid, new_dirid);
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BUG_ON(ret);
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inode->i_nlink = 1;
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inode->i_size = 6;
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ret = btrfs_update_inode(trans, new_root, inode);
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BUG_ON(ret);
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ret = btrfs_commit_transaction(trans, new_root);
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BUG_ON(ret);
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iput(inode);
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mutex_unlock(&root->fs_info->fs_mutex);
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return 0;
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}
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static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
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{
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struct btrfs_trans_handle *trans;
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@ -1674,6 +1782,9 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
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int ret;
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u64 objectid;
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if (!root->ref_cows)
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return -EINVAL;
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mutex_lock(&root->fs_info->fs_mutex);
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trans = btrfs_start_transaction(root, 1);
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BUG_ON(!trans);
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@ -1685,7 +1796,6 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
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0, &objectid);
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BUG_ON(ret);
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memset(&new_root_item, 0, sizeof(new_root_item));
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memcpy(&new_root_item, &root->root_item,
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sizeof(new_root_item));
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@ -1728,9 +1838,9 @@ static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
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struct btrfs_ioctl_vol_args vol_args;
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int ret;
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int namelen;
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struct btrfs_path *path;
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u64 root_dirid;
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if (!root->ref_cows)
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return -EINVAL;
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switch (cmd) {
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case BTRFS_IOC_SNAP_CREATE:
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if (copy_from_user(&vol_args,
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@ -1740,7 +1850,23 @@ static int btrfs_ioctl(struct inode *inode, struct file *filp, unsigned int
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namelen = strlen(vol_args.name);
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if (namelen > BTRFS_VOL_NAME_MAX)
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return -EINVAL;
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ret = create_snapshot(root, vol_args.name, namelen);
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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root_dirid = btrfs_root_dirid(
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&root->fs_info->tree_root->root_item);
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mutex_lock(&root->fs_info->fs_mutex);
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ret = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root,
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path, root_dirid,
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vol_args.name, namelen, 0);
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mutex_unlock(&root->fs_info->fs_mutex);
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if (ret == 0)
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return -EEXIST;
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if (root == root->fs_info->tree_root)
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ret = create_subvol(root, vol_args.name, namelen);
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else
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ret = create_snapshot(root, vol_args.name, namelen);
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WARN_ON(ret);
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break;
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default:
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@ -64,7 +64,8 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
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if (root != root->fs_info->tree_root && root->last_trans <
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running_trans_id) {
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radix_tree_tag_set(&root->fs_info->fs_roots_radix,
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(unsigned long)root, BTRFS_ROOT_TRANS_TAG);
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(unsigned long)root->root_key.objectid,
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BTRFS_ROOT_TRANS_TAG);
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root->commit_root = root->node;
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get_bh(root->node);
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}
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@ -171,8 +172,9 @@ int add_dirty_roots(struct btrfs_trans_handle *trans,
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break;
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for (i = 0; i < ret; i++) {
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root = gang[i];
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radix_tree_tag_clear(radix, (unsigned long)root,
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BTRFS_ROOT_TRANS_TAG);
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radix_tree_tag_clear(radix,
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(unsigned long)root->root_key.objectid,
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BTRFS_ROOT_TRANS_TAG);
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if (root->commit_root == root->node) {
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WARN_ON(root->node->b_blocknr !=
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btrfs_root_blocknr(&root->root_item));
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