diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/inode.c | 264 |
1 files changed, 257 insertions, 7 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 422833e..452cfef 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9394,8 +9394,244 @@ static int btrfs_getattr(struct vfsmount *mnt, return 0; } +static int btrfs_rename_exchange(struct inode *old_dir, + struct dentry *old_dentry, + struct inode *new_dir, + struct dentry *new_dentry) +{ + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(old_dir)->root; + struct btrfs_root *dest = BTRFS_I(new_dir)->root; + struct inode *new_inode = new_dentry->d_inode; + struct inode *old_inode = old_dentry->d_inode; + struct timespec ctime = CURRENT_TIME; + struct dentry *parent; + u64 old_ino = btrfs_ino(old_inode); + u64 new_ino = btrfs_ino(new_inode); + u64 old_idx = 0; + u64 new_idx = 0; + u64 root_objectid; + int ret; + + /* we only allow rename subvolume link between subvolumes */ + if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) + return -EXDEV; + + /* close the race window with snapshot create/destroy ioctl */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + down_read(&root->fs_info->subvol_sem); + if (new_ino == BTRFS_FIRST_FREE_OBJECTID) + down_read(&dest->fs_info->subvol_sem); + + /* + * We want to reserve the absolute worst case amount of items. So if + * both inodes are subvols and we need to unlink them then that would + * require 4 item modifications, but if they are both normal inodes it + * would require 5 item modifications, so we'll assume their normal + * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items + * should cover the worst case number of items we'll modify. + */ + trans = btrfs_start_transaction(root, 12); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_notrans; + } + + /* + * We need to find a free sequence number both in the source and + * in the destination directory for the exchange. + */ + ret = btrfs_set_inode_index(new_dir, &old_idx); + if (ret) + goto out_fail; + ret = btrfs_set_inode_index(old_dir, &new_idx); + if (ret) + goto out_fail; + + BTRFS_I(old_inode)->dir_index = 0ULL; + BTRFS_I(new_inode)->dir_index = 0ULL; + + /* Reference for the source. */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) { + /* force full log commit if subvolume involved. */ + btrfs_set_log_full_commit(root->fs_info, trans); + } else { + ret = btrfs_insert_inode_ref(trans, dest, + new_dentry->d_name.name, + new_dentry->d_name.len, + old_ino, + btrfs_ino(new_dir), old_idx); + if (ret) + goto out_fail; + btrfs_pin_log_trans(root); + } + + /* And now for the dest. */ + if (new_ino == BTRFS_FIRST_FREE_OBJECTID) { + /* force full log commit if subvolume involved. */ + btrfs_set_log_full_commit(dest->fs_info, trans); + } else { + ret = btrfs_insert_inode_ref(trans, root, + old_dentry->d_name.name, + old_dentry->d_name.len, + new_ino, + btrfs_ino(old_dir), new_idx); + if (ret) + goto out_fail; + btrfs_pin_log_trans(dest); + } + + /* Update inode version and ctime/mtime. */ + inode_inc_iversion(old_dir); + inode_inc_iversion(new_dir); + inode_inc_iversion(old_inode); + inode_inc_iversion(new_inode); + old_dir->i_ctime = old_dir->i_mtime = ctime; + new_dir->i_ctime = new_dir->i_mtime = ctime; + old_inode->i_ctime = ctime; + new_inode->i_ctime = ctime; + + if (old_dentry->d_parent != new_dentry->d_parent) { + btrfs_record_unlink_dir(trans, old_dir, old_inode, 1); + btrfs_record_unlink_dir(trans, new_dir, new_inode, 1); + } + + /* src is a subvolume */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) { + root_objectid = BTRFS_I(old_inode)->root->root_key.objectid; + ret = btrfs_unlink_subvol(trans, root, old_dir, + root_objectid, + old_dentry->d_name.name, + old_dentry->d_name.len); + } else { /* src is an inode */ + ret = __btrfs_unlink_inode(trans, root, old_dir, + old_dentry->d_inode, + old_dentry->d_name.name, + old_dentry->d_name.len); + if (!ret) + ret = btrfs_update_inode(trans, root, old_inode); + } + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + + /* dest is a subvolume */ + if (new_ino == BTRFS_FIRST_FREE_OBJECTID) { + root_objectid = BTRFS_I(new_inode)->root->root_key.objectid; + ret = btrfs_unlink_subvol(trans, dest, new_dir, + root_objectid, + new_dentry->d_name.name, + new_dentry->d_name.len); + } else { /* dest is an inode */ + ret = __btrfs_unlink_inode(trans, dest, new_dir, + new_dentry->d_inode, + new_dentry->d_name.name, + new_dentry->d_name.len); + if (!ret) + ret = btrfs_update_inode(trans, dest, new_inode); + } + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + + ret = btrfs_add_link(trans, new_dir, old_inode, + new_dentry->d_name.name, + new_dentry->d_name.len, 0, old_idx); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + + ret = btrfs_add_link(trans, old_dir, new_inode, + old_dentry->d_name.name, + old_dentry->d_name.len, 0, new_idx); + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + + if (old_inode->i_nlink == 1) + BTRFS_I(old_inode)->dir_index = old_idx; + if (new_inode->i_nlink == 1) + BTRFS_I(new_inode)->dir_index = new_idx; + + if (old_ino != BTRFS_FIRST_FREE_OBJECTID) { + parent = new_dentry->d_parent; + btrfs_log_new_name(trans, old_inode, old_dir, parent); + btrfs_end_log_trans(root); + } + if (new_ino != BTRFS_FIRST_FREE_OBJECTID) { + parent = old_dentry->d_parent; + btrfs_log_new_name(trans, new_inode, new_dir, parent); + btrfs_end_log_trans(dest); + } +out_fail: + ret = btrfs_end_transaction(trans, root); +out_notrans: + if (new_ino == BTRFS_FIRST_FREE_OBJECTID) + up_read(&dest->fs_info->subvol_sem); + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + up_read(&root->fs_info->subvol_sem); + + return ret; +} + +static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, + struct dentry *dentry) +{ + int ret; + struct inode *inode; + u64 objectid; + u64 index; + + ret = btrfs_find_free_ino(root, &objectid); + if (ret) + return ret; + + inode = btrfs_new_inode(trans, root, dir, + dentry->d_name.name, + dentry->d_name.len, + btrfs_ino(dir), + objectid, + S_IFCHR | WHITEOUT_MODE, + &index); + + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + return ret; + } + + inode->i_op = &btrfs_special_inode_operations; + init_special_inode(inode, inode->i_mode, + WHITEOUT_DEV); + + ret = btrfs_init_inode_security(trans, inode, dir, + &dentry->d_name); + if (ret) + return ret; + + ret = btrfs_add_nondir(trans, dir, dentry, + inode, 0, index); + if (ret) + return ret; + + ret = btrfs_update_inode(trans, root, inode); + if (ret) + return ret; + + unlock_new_inode(inode); + iput(inode); + + return 0; +} + static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(old_dir)->root; @@ -9457,15 +9693,15 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, * We want to reserve the absolute worst case amount of items. So if * both inodes are subvols and we need to unlink them then that would * require 4 item modifications, but if they are both normal inodes it - * would require 5 item modifications, so we'll assume their normal + * would require 5 item modifications, so we'll assume they are normal * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items * should cover the worst case number of items we'll modify. */ trans = btrfs_start_transaction(root, 11); if (IS_ERR(trans)) { - ret = PTR_ERR(trans); - goto out_notrans; - } + ret = PTR_ERR(trans); + goto out_notrans; + } if (dest != root) btrfs_record_root_in_trans(trans, dest); @@ -9561,6 +9797,16 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, btrfs_end_log_trans(root); log_pinned = false; } + + if (flags & RENAME_WHITEOUT) { + ret = btrfs_whiteout_for_rename(trans, root, old_dir, + old_dentry); + + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto out_fail; + } + } out_fail: /* * If we have pinned the log and an error happened, we unpin tasks @@ -9596,10 +9842,14 @@ static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { - if (flags & ~RENAME_NOREPLACE) + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) return -EINVAL; - return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry); + if (flags & RENAME_EXCHANGE) + return btrfs_rename_exchange(old_dir, old_dentry, new_dir, + new_dentry); + + return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags); } static void btrfs_run_delalloc_work(struct btrfs_work *work) |
