From patchwork Tue May 14 09:36:56 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Behrens X-Patchwork-Id: 2563691 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id EF2E7DF24C for ; Tue, 14 May 2013 09:37:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756901Ab3ENJhN (ORCPT ); Tue, 14 May 2013 05:37:13 -0400 Received: from xp-ob.rzone.de ([81.169.146.140]:46308 "EHLO xp-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756766Ab3ENJhE (ORCPT ); Tue, 14 May 2013 05:37:04 -0400 X-RZG-CLASS-ID: xp Received: from pizpot.store ([192.168.43.236]) by joses.store (joses xp3) (RZmta 31.27 OK) with ESMTP id p01f2dp4E0wk26 for ; Tue, 14 May 2013 11:37:01 +0200 (CEST) From: Stefan Behrens To: linux-btrfs@vger.kernel.org Subject: [PATCH v2 4/8] Btrfs: maintain subvolume items in the UUID tree Date: Tue, 14 May 2013 11:36:56 +0200 Message-Id: X-Mailer: git-send-email 1.8.2.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org When a new subvolume or snapshot is created, a new UUID item is added to the UUID tree. Such items are removed when the subvolume is deleted. The ioctl to set the received subvolume UUID is also touched and will now also add this received UUID into the UUID tree together with the ID of the subvolume. The latter is also done when read-only snapshots are created which inherit all the send/receive information from the parent subvolume. User mode programs use the BTRFS_IOC_TREE_SEARCH ioctl to search and read in the UUID tree. Signed-off-by: Stefan Behrens --- fs/btrfs/ctree.h | 1 + fs/btrfs/ioctl.c | 74 +++++++++++++++++++++++++++++++++++++++++++------- fs/btrfs/transaction.c | 19 ++++++++++++- 3 files changed, 83 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 6f9d760..73d797c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3634,6 +3634,7 @@ extern const struct dentry_operations btrfs_dentry_operations; long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg); void btrfs_update_iflags(struct inode *inode); void btrfs_inherit_iflags(struct inode *inode, struct inode *dir); +int btrfs_is_empty_uuid(u8 *uuid); int btrfs_defrag_file(struct inode *inode, struct file *file, struct btrfs_ioctl_defrag_range_args *range, u64 newer_than, unsigned long max_pages); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index b2537c7..47bef5a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -363,6 +363,13 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) return 0; } +int btrfs_is_empty_uuid(u8 *uuid) +{ + static char empty_uuid[BTRFS_UUID_SIZE] = {0}; + + return !memcmp(uuid, empty_uuid, BTRFS_UUID_SIZE); +} + static noinline int create_subvol(struct inode *dir, struct dentry *dentry, char *name, int namelen, @@ -396,7 +403,7 @@ static noinline int create_subvol(struct inode *dir, * of create_snapshot(). */ ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, - 7, &qgroup_reserved); + 8, &qgroup_reserved); if (ret) return ret; @@ -518,9 +525,13 @@ static noinline int create_subvol(struct inode *dir, ret = btrfs_add_root_ref(trans, root->fs_info->tree_root, objectid, root->root_key.objectid, btrfs_ino(dir), index, name, namelen); - BUG_ON(ret); + ret = btrfs_insert_uuid_subvol_item(trans, root->fs_info->uuid_root, + root_item.uuid, objectid); + if (ret) + btrfs_abort_transaction(trans, root, ret); + fail: trans->block_rsv = NULL; trans->bytes_reserved = 0; @@ -567,9 +578,10 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir, * 1 - root item * 2 - root ref/backref * 1 - root of snapshot + * 1 - UUID item */ ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root, - &pending_snapshot->block_rsv, 7, + &pending_snapshot->block_rsv, 8, &pending_snapshot->qgroup_reserved); if (ret) goto out; @@ -2207,6 +2219,27 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file, goto out_end_trans; } } + + ret = btrfs_del_uuid_subvol_item(trans, root->fs_info->uuid_root, + dest->root_item.uuid, + dest->root_key.objectid); + if (ret && ret != -ENOENT) { + btrfs_abort_transaction(trans, root, ret); + err = ret; + goto out_end_trans; + } + if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) { + ret = btrfs_del_uuid_received_subvol_item(trans, + root->fs_info->uuid_root, + dest->root_item.received_uuid, + dest->root_key.objectid); + if (ret && ret != -ENOENT) { + btrfs_abort_transaction(trans, root, ret); + err = ret; + goto out_end_trans; + } + } + out_end_trans: trans->block_rsv = NULL; trans->bytes_reserved = 0; @@ -2418,7 +2451,6 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg) struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; int ret = 0; char *s_uuid = NULL; - char empty_uuid[BTRFS_UUID_SIZE] = {0}; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -2427,7 +2459,7 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg) if (IS_ERR(di_args)) return PTR_ERR(di_args); - if (memcmp(empty_uuid, di_args->uuid, BTRFS_UUID_SIZE) != 0) + if (!btrfs_is_empty_uuid(di_args->uuid)) s_uuid = di_args->uuid; mutex_lock(&fs_devices->device_list_mutex); @@ -3952,6 +3984,7 @@ static long btrfs_ioctl_set_received_subvol(struct file *file, struct btrfs_trans_handle *trans; struct timespec ct = CURRENT_TIME; int ret = 0; + int received_uuid_changed; ret = mnt_want_write_file(file); if (ret < 0) @@ -3981,7 +4014,11 @@ static long btrfs_ioctl_set_received_subvol(struct file *file, goto out; } - trans = btrfs_start_transaction(root, 1); + /* + * 1 - root item + * 2 - uuid items (received uuid + subvol uuid) + */ + trans = btrfs_start_transaction(root, 3); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; @@ -3992,6 +4029,14 @@ static long btrfs_ioctl_set_received_subvol(struct file *file, sa->rtime.sec = ct.tv_sec; sa->rtime.nsec = ct.tv_nsec; + received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid, + BTRFS_UUID_SIZE); + if (received_uuid_changed && + !btrfs_is_empty_uuid(root_item->received_uuid)) + btrfs_del_uuid_received_subvol_item(trans, + root->fs_info->uuid_root, + root_item->received_uuid, + root->root_key.objectid); memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE); btrfs_set_root_stransid(root_item, sa->stransid); btrfs_set_root_rtransid(root_item, sa->rtransid); @@ -4004,12 +4049,21 @@ static long btrfs_ioctl_set_received_subvol(struct file *file, &root->root_key, &root->root_item); if (ret < 0) { btrfs_end_transaction(trans, root); - trans = NULL; goto out; - } else { - ret = btrfs_commit_transaction(trans, root); - if (ret < 0) + } + if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) { + ret = btrfs_insert_uuid_received_subvol_item( + trans, root->fs_info->uuid_root, sa->uuid, + root->root_key.objectid); + if (ret < 0 && ret != -EEXIST) { + btrfs_abort_transaction(trans, root, ret); goto out; + } + } + ret = btrfs_commit_transaction(trans, root); + if (ret < 0) { + btrfs_abort_transaction(trans, root, ret); + goto out; } ret = copy_to_user(arg, sa, sizeof(*sa)); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 0544587..a3d92b3 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1263,8 +1263,25 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans, dentry->d_name.len * 2); parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME; ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode); - if (ret) + if (ret) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + ret = btrfs_insert_uuid_subvol_item(trans, fs_info->uuid_root, + new_uuid.b, objectid); + if (ret) { btrfs_abort_transaction(trans, root, ret); + goto fail; + } + if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) { + ret = btrfs_insert_uuid_received_subvol_item( + trans, fs_info->uuid_root, new_root_item->received_uuid, + objectid); + if (ret && ret != -EEXIST) { + btrfs_abort_transaction(trans, root, ret); + goto fail; + } + } fail: pending->error = ret; dir_item_existed: