From patchwork Mon Apr 25 11:18:32 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Sterba X-Patchwork-Id: 8925521 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 1AC0DBF29F for ; Mon, 25 Apr 2016 11:18:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F233620173 for ; Mon, 25 Apr 2016 11:18:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C397A20172 for ; Mon, 25 Apr 2016 11:18:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754382AbcDYLSt (ORCPT ); Mon, 25 Apr 2016 07:18:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:32835 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754198AbcDYLSt (ORCPT ); Mon, 25 Apr 2016 07:18:49 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 72A31AC3A; Mon, 25 Apr 2016 11:18:45 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 8D165DAA46; Mon, 25 Apr 2016 13:18:37 +0200 (CEST) From: David Sterba To: linux-btrfs@vger.kernel.org Cc: t-itoh@jp.fujitsu.com, David Sterba Subject: [PATCH v2] btrfs: use dynamic allocation for root item in create_subvol Date: Mon, 25 Apr 2016 13:18:32 +0200 Message-Id: <1461583112-3646-1-git-send-email-dsterba@suse.com> X-Mailer: git-send-email 2.7.1 In-Reply-To: <7d013acc6e07b39bd224f9c0097775c0a8e138df.1460397148.git.dsterba@suse.com> References: <7d013acc6e07b39bd224f9c0097775c0a8e138df.1460397148.git.dsterba@suse.com> 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 Reviewed-by: Tsutomu Itoh --- fs/btrfs/ioctl.c | 65 ++++++++++++++++++++++++++++++++------------------------ 1 file changed, 37 insertions(+), 28 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 053e677839fe..9a63fe07bc2e 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; @@ -455,16 +455,22 @@ 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; + goto fail_free; /* * Don't create subvolume whose level is not zero. Or qgroup will be * screwed up since it assume subvolme qgroup's level to be 0. */ - if (btrfs_qgroup_level(objectid)) - return -ENOSPC; + if (btrfs_qgroup_level(objectid)) { + ret = -ENOSPC; + goto fail_free; + } btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP); /* @@ -474,14 +480,14 @@ static noinline int create_subvol(struct inode *dir, ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, &qgroup_reserved, false); if (ret) - return ret; + goto fail_free; trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved); - return ret; + goto fail_free; } trans->block_rsv = &block_rsv; trans->bytes_reserved = block_rsv.size; @@ -509,47 +515,45 @@ 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 +605,13 @@ 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); @@ -629,6 +634,10 @@ static noinline int create_subvol(struct inode *dir, d_instantiate(dentry, inode); } return ret; + +fail_free: + kfree(root_item); + return ret; } static void btrfs_wait_for_no_snapshoting_writes(struct btrfs_root *root)