From patchwork Mon Apr 11 18:04:32 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Sterba X-Patchwork-Id: 8804871 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E30509F36E for ; Mon, 11 Apr 2016 18:08:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DBFB7202F8 for ; Mon, 11 Apr 2016 18:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54E8C20253 for ; Mon, 11 Apr 2016 18:08:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753318AbcDKSIL (ORCPT ); Mon, 11 Apr 2016 14:08:11 -0400 Received: from mx2.suse.de ([195.135.220.15]:58039 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753109AbcDKSIJ (ORCPT ); Mon, 11 Apr 2016 14:08:09 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 11479ABB4 for ; Mon, 11 Apr 2016 18:08:07 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 65750DAB68; Mon, 11 Apr 2016 20:04:32 +0200 (CEST) From: David Sterba To: linux-btrfs@vger.kernel.org Cc: David Sterba Subject: [PATCH 1/2] btrfs: use dynamic allocation for root item in create_subvol Date: Mon, 11 Apr 2016 20:04:32 +0200 Message-Id: <7d013acc6e07b39bd224f9c0097775c0a8e138df.1460397148.git.dsterba@suse.com> X-Mailer: git-send-email 2.7.1 In-Reply-To: References: Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The size of root item is more than 400 bytes, which is quite a lot of stack space. As we do IO from inside the subvolume ioctls, we should keep the stack usage low in case the filesystem is on top of other layers (NFS, device mapper, iscsi, etc). Signed-off-by: David Sterba --- fs/btrfs/ioctl.c | 49 ++++++++++++++++++++++++++----------------------- 1 file changed, 26 insertions(+), 23 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 053e677839fe..0be13b9c53d9 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -439,7 +439,7 @@ static noinline int create_subvol(struct inode *dir, { struct btrfs_trans_handle *trans; struct btrfs_key key; - struct btrfs_root_item root_item; + struct btrfs_root_item *root_item; struct btrfs_inode_item *inode_item; struct extent_buffer *leaf; struct btrfs_root *root = BTRFS_I(dir)->root; @@ -455,6 +455,10 @@ static noinline int create_subvol(struct inode *dir, u64 qgroup_reserved; uuid_le new_uuid; + root_item = kzalloc(sizeof(*root_item), GFP_KERNEL); + if (!root_item) + return -ENOMEM; + ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid); if (ret) return ret; @@ -509,47 +513,45 @@ static noinline int create_subvol(struct inode *dir, BTRFS_UUID_SIZE); btrfs_mark_buffer_dirty(leaf); - memset(&root_item, 0, sizeof(root_item)); - - inode_item = &root_item.inode; + inode_item = &root_item->inode; btrfs_set_stack_inode_generation(inode_item, 1); btrfs_set_stack_inode_size(inode_item, 3); btrfs_set_stack_inode_nlink(inode_item, 1); btrfs_set_stack_inode_nbytes(inode_item, root->nodesize); btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755); - btrfs_set_root_flags(&root_item, 0); - btrfs_set_root_limit(&root_item, 0); + btrfs_set_root_flags(root_item, 0); + btrfs_set_root_limit(root_item, 0); btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT); - btrfs_set_root_bytenr(&root_item, leaf->start); - btrfs_set_root_generation(&root_item, trans->transid); - btrfs_set_root_level(&root_item, 0); - btrfs_set_root_refs(&root_item, 1); - btrfs_set_root_used(&root_item, leaf->len); - btrfs_set_root_last_snapshot(&root_item, 0); + btrfs_set_root_bytenr(root_item, leaf->start); + btrfs_set_root_generation(root_item, trans->transid); + btrfs_set_root_level(root_item, 0); + btrfs_set_root_refs(root_item, 1); + btrfs_set_root_used(root_item, leaf->len); + btrfs_set_root_last_snapshot(root_item, 0); - btrfs_set_root_generation_v2(&root_item, - btrfs_root_generation(&root_item)); + btrfs_set_root_generation_v2(root_item, + btrfs_root_generation(root_item)); uuid_le_gen(&new_uuid); - memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE); - btrfs_set_stack_timespec_sec(&root_item.otime, cur_time.tv_sec); - btrfs_set_stack_timespec_nsec(&root_item.otime, cur_time.tv_nsec); - root_item.ctime = root_item.otime; - btrfs_set_root_ctransid(&root_item, trans->transid); - btrfs_set_root_otransid(&root_item, trans->transid); + memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE); + btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec); + btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec); + root_item->ctime = root_item->otime; + btrfs_set_root_ctransid(root_item, trans->transid); + btrfs_set_root_otransid(root_item, trans->transid); btrfs_tree_unlock(leaf); free_extent_buffer(leaf); leaf = NULL; - btrfs_set_root_dirid(&root_item, new_dirid); + btrfs_set_root_dirid(root_item, new_dirid); key.objectid = objectid; key.offset = 0; key.type = BTRFS_ROOT_ITEM_KEY; ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key, - &root_item); + root_item); if (ret) goto fail; @@ -601,12 +603,13 @@ static noinline int create_subvol(struct inode *dir, BUG_ON(ret); ret = btrfs_uuid_tree_add(trans, root->fs_info->uuid_root, - root_item.uuid, BTRFS_UUID_KEY_SUBVOL, + root_item->uuid, BTRFS_UUID_KEY_SUBVOL, objectid); if (ret) btrfs_abort_transaction(trans, root, ret); fail: + kfree(root_item); trans->block_rsv = NULL; trans->bytes_reserved = 0; btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);