Commit 2b8d99a7 authored by Chris Mason's avatar Chris Mason Committed by David Woodhouse

Btrfs: symlinks and hard links

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent e06afa83
......@@ -26,11 +26,13 @@ struct btrfs_iget_args {
#define BTRFS_SUPER_MAGIC 0x9123682E
static struct inode_operations btrfs_dir_inode_operations;
static struct inode_operations btrfs_symlink_inode_operations;
static struct inode_operations btrfs_dir_ro_inode_operations;
static struct super_operations btrfs_super_ops;
static struct file_operations btrfs_dir_file_operations;
static struct inode_operations btrfs_file_inode_operations;
static struct address_space_operations btrfs_aops;
static struct address_space_operations btrfs_symlink_aops;
static struct file_operations btrfs_file_operations;
static void btrfs_read_locked_inode(struct inode *inode)
......@@ -103,7 +105,8 @@ static void btrfs_read_locked_inode(struct inode *inode)
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
// inode->i_op = &page_symlink_inode_operations;
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
break;
}
return;
......@@ -940,6 +943,41 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
return err;
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = old_dentry->d_inode;
int err;
int drop_inode = 0;
if (inode->i_nlink == 0)
return -ENOENT;
inc_nlink(inode);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
atomic_inc(&inode->i_count);
err = btrfs_add_nondir(trans, dentry, inode);
if (err)
drop_inode = 1;
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, dir);
btrfs_update_inode(trans, root, inode);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
}
static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 dirid)
......@@ -2577,33 +2615,25 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
}
ret = btrfs_add_link(trans, new_dentry, old_inode);
if (ret == -EEXIST && new_inode)
ret = 0;
else if (ret)
goto out_fail;
ret = btrfs_unlink_trans(trans, root, old_dir, old_dentry);
if (ret)
goto out_fail;
if (new_inode) {
new_inode->i_ctime = CURRENT_TIME;
di = btrfs_lookup_dir_index_item(trans, root, path,
new_dir->i_ino,
new_inode->i_ino,
new_dentry->d_name.name,
new_dentry->d_name.len, -1);
if (di && !IS_ERR(di)) {
btrfs_del_item(trans, root, path);
btrfs_release_path(root, path);
}
ret = btrfs_unlink_trans(trans, root, new_dir, new_dentry);
if (ret)
goto out_fail;
if (S_ISDIR(new_inode->i_mode))
clear_nlink(new_inode);
else
drop_nlink(new_inode);
btrfs_update_inode(trans, root, new_inode);
}
ret = btrfs_add_link(trans, new_dentry, old_inode);
if (ret)
goto out_fail;
out_fail:
btrfs_free_path(path);
btrfs_end_transaction(trans, root);
......@@ -2611,6 +2641,94 @@ static int btrfs_rename(struct inode * old_dir, struct dentry *old_dentry,
return ret;
}
static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode;
int err;
int drop_inode = 0;
u64 objectid;
int name_len;
int datasize;
char *ptr;
struct btrfs_file_extent_item *ei;
name_len = strlen(symname) + 1;
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
return -ENAMETOOLONG;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_set_trans_block_group(trans, dir);
err = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
if (err) {
err = -ENOSPC;
goto out_unlock;
}
inode = btrfs_new_inode(trans, root, objectid,
BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
btrfs_set_trans_block_group(trans, inode);
err = btrfs_add_nondir(trans, dentry, inode);
if (err)
drop_inode = 1;
else {
inode->i_mapping->a_ops = &btrfs_aops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
}
dir->i_sb->s_dirt = 1;
btrfs_update_inode_block_group(trans, inode);
btrfs_update_inode_block_group(trans, dir);
if (drop_inode)
goto out_unlock;
path = btrfs_alloc_path();
BUG_ON(!path);
key.objectid = inode->i_ino;
key.offset = 0;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
BUG_ON(err);
ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0], struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(ei, trans->transid);
btrfs_set_file_extent_type(ei,
BTRFS_FILE_EXTENT_INLINE);
ptr = btrfs_file_extent_inline_start(ei);
btrfs_memcpy(root, path->nodes[0]->b_data,
ptr, symname, name_len);
mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode->i_size = name_len - 1;
btrfs_update_inode(trans, root, inode);
err = 0;
out_unlock:
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
}
static struct file_system_type btrfs_fs_type = {
.owner = THIS_MODULE,
.name = "btrfs",
......@@ -2636,9 +2754,11 @@ static struct inode_operations btrfs_dir_inode_operations = {
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename = btrfs_rename,
.symlink = btrfs_symlink,
};
static struct inode_operations btrfs_dir_ro_inode_operations = {
......@@ -2660,6 +2780,11 @@ static struct address_space_operations btrfs_aops = {
.commit_write = btrfs_commit_write,
};
static struct address_space_operations btrfs_symlink_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
};
static struct inode_operations btrfs_file_inode_operations = {
.truncate = btrfs_truncate,
.getattr = btrfs_getattr,
......@@ -2676,6 +2801,12 @@ static struct file_operations btrfs_file_operations = {
.fsync = btrfs_sync_file,
};
static struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
};
static int __init init_btrfs_fs(void)
{
int err;
......
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