From 2b8d99a723a3186a69b5bd941a272dbecae9205b Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Thu, 24 May 2007 08:34:10 -0400 Subject: [PATCH] Btrfs: symlinks and hard links Signed-off-by: Chris Mason --- fs/btrfs/super.c | 163 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 147 insertions(+), 16 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index f49cad603ee8..c1a0adde9b1c 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -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 @@ out_unlock: 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 @@ out_fail: 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; -- 2.20.1