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Btrfs: symlinks and hard links
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
David Woodhouse
parent
e06afa839e
commit
2b8d99a723
163
fs/btrfs/super.c
163
fs/btrfs/super.c
@ -26,11 +26,13 @@ struct btrfs_iget_args {
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#define BTRFS_SUPER_MAGIC 0x9123682E
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static struct inode_operations btrfs_dir_inode_operations;
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static struct inode_operations btrfs_symlink_inode_operations;
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static struct inode_operations btrfs_dir_ro_inode_operations;
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static struct super_operations btrfs_super_ops;
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static struct file_operations btrfs_dir_file_operations;
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static struct inode_operations btrfs_file_inode_operations;
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static struct address_space_operations btrfs_aops;
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static struct address_space_operations btrfs_symlink_aops;
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static struct file_operations btrfs_file_operations;
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static void btrfs_read_locked_inode(struct inode *inode)
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@ -103,7 +105,8 @@ static void btrfs_read_locked_inode(struct inode *inode)
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inode->i_op = &btrfs_dir_inode_operations;
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break;
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case S_IFLNK:
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// inode->i_op = &page_symlink_inode_operations;
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inode->i_op = &btrfs_symlink_inode_operations;
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inode->i_mapping->a_ops = &btrfs_symlink_aops;
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break;
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}
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return;
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@ -940,6 +943,41 @@ out_unlock:
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return err;
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}
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static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
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struct dentry *dentry)
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{
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struct btrfs_trans_handle *trans;
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struct btrfs_root *root = BTRFS_I(dir)->root;
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struct inode *inode = old_dentry->d_inode;
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int err;
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int drop_inode = 0;
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if (inode->i_nlink == 0)
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return -ENOENT;
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inc_nlink(inode);
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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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btrfs_set_trans_block_group(trans, dir);
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atomic_inc(&inode->i_count);
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err = btrfs_add_nondir(trans, dentry, inode);
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if (err)
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drop_inode = 1;
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dir->i_sb->s_dirt = 1;
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btrfs_update_inode_block_group(trans, dir);
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btrfs_update_inode(trans, root, inode);
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btrfs_end_transaction(trans, root);
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mutex_unlock(&root->fs_info->fs_mutex);
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if (drop_inode) {
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inode_dec_link_count(inode);
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iput(inode);
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}
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btrfs_btree_balance_dirty(root);
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return err;
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}
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static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 objectid, u64 dirid)
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@ -2577,33 +2615,25 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
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}
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ret = btrfs_add_link(trans, new_dentry, old_inode);
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if (ret == -EEXIST && new_inode)
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ret = 0;
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else if (ret)
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goto out_fail;
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ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
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if (ret)
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goto out_fail;
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if (new_inode) {
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new_inode->i_ctime = CURRENT_TIME;
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di = btrfs_lookup_dir_index_item(trans, root, path,
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new_dir->i_ino,
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new_inode->i_ino,
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new_dentry->d_name.name,
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new_dentry->d_name.len, -1);
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if (di && !IS_ERR(di)) {
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btrfs_del_item(trans, root, path);
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btrfs_release_path(root, path);
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}
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ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
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if (ret)
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goto out_fail;
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if (S_ISDIR(new_inode->i_mode))
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clear_nlink(new_inode);
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else
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drop_nlink(new_inode);
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btrfs_update_inode(trans, root, new_inode);
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}
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ret = btrfs_add_link(trans, new_dentry, old_inode);
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if (ret)
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goto out_fail;
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out_fail:
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btrfs_free_path(path);
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btrfs_end_transaction(trans, root);
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@ -2611,6 +2641,94 @@ out_fail:
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return ret;
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}
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static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
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const char *symname)
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{
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struct btrfs_trans_handle *trans;
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struct btrfs_root *root = BTRFS_I(dir)->root;
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struct btrfs_path *path;
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struct btrfs_key key;
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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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int name_len;
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int datasize;
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char *ptr;
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struct btrfs_file_extent_item *ei;
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name_len = strlen(symname) + 1;
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if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
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return -ENAMETOOLONG;
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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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btrfs_set_trans_block_group(trans, dir);
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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,
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BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
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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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btrfs_set_trans_block_group(trans, inode);
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err = btrfs_add_nondir(trans, dentry, inode);
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if (err)
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drop_inode = 1;
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else {
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inode->i_mapping->a_ops = &btrfs_aops;
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inode->i_fop = &btrfs_file_operations;
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inode->i_op = &btrfs_file_inode_operations;
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}
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dir->i_sb->s_dirt = 1;
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btrfs_update_inode_block_group(trans, inode);
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btrfs_update_inode_block_group(trans, dir);
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if (drop_inode)
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goto out_unlock;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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key.objectid = inode->i_ino;
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key.offset = 0;
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key.flags = 0;
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btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
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datasize = btrfs_file_extent_calc_inline_size(name_len);
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err = btrfs_insert_empty_item(trans, root, path, &key,
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datasize);
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BUG_ON(err);
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ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
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path->slots[0], struct btrfs_file_extent_item);
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btrfs_set_file_extent_generation(ei, trans->transid);
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btrfs_set_file_extent_type(ei,
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BTRFS_FILE_EXTENT_INLINE);
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ptr = btrfs_file_extent_inline_start(ei);
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btrfs_memcpy(root, path->nodes[0]->b_data,
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ptr, symname, name_len);
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mark_buffer_dirty(path->nodes[0]);
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btrfs_free_path(path);
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inode->i_op = &btrfs_symlink_inode_operations;
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inode->i_mapping->a_ops = &btrfs_symlink_aops;
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inode->i_size = name_len - 1;
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btrfs_update_inode(trans, root, inode);
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err = 0;
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out_unlock:
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btrfs_end_transaction(trans, root);
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mutex_unlock(&root->fs_info->fs_mutex);
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if (drop_inode) {
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inode_dec_link_count(inode);
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iput(inode);
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}
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btrfs_btree_balance_dirty(root);
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return err;
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}
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static struct file_system_type btrfs_fs_type = {
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.owner = THIS_MODULE,
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.name = "btrfs",
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@ -2636,9 +2754,11 @@ static struct inode_operations btrfs_dir_inode_operations = {
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.lookup = btrfs_lookup,
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.create = btrfs_create,
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.unlink = btrfs_unlink,
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.link = btrfs_link,
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.mkdir = btrfs_mkdir,
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.rmdir = btrfs_rmdir,
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.rename = btrfs_rename,
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.symlink = btrfs_symlink,
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};
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static struct inode_operations btrfs_dir_ro_inode_operations = {
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@ -2660,6 +2780,11 @@ static struct address_space_operations btrfs_aops = {
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.commit_write = btrfs_commit_write,
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};
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static struct address_space_operations btrfs_symlink_aops = {
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.readpage = btrfs_readpage,
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.writepage = btrfs_writepage,
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};
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static struct inode_operations btrfs_file_inode_operations = {
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.truncate = btrfs_truncate,
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.getattr = btrfs_getattr,
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@ -2676,6 +2801,12 @@ static struct file_operations btrfs_file_operations = {
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.fsync = btrfs_sync_file,
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};
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static struct inode_operations btrfs_symlink_inode_operations = {
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.readlink = generic_readlink,
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.follow_link = page_follow_link_light,
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.put_link = page_put_link,
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};
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static int __init init_btrfs_fs(void)
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{
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int err;
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