From patchwork Tue Jun 30 21:42:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Fasheh X-Patchwork-Id: 6698451 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 1DEB7C05AD for ; Tue, 30 Jun 2015 21:43:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 36435204D3 for ; Tue, 30 Jun 2015 21:43:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 137F42062A for ; Tue, 30 Jun 2015 21:43:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751509AbbF3VmX (ORCPT ); Tue, 30 Jun 2015 17:42:23 -0400 Received: from cantor2.suse.de ([195.135.220.15]:55422 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750940AbbF3VmW (ORCPT ); Tue, 30 Jun 2015 17:42:22 -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 3708AADDF; Tue, 30 Jun 2015 21:42:21 +0000 (UTC) From: Mark Fasheh To: Chris Mason Cc: Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, Mark Fasheh Subject: [PATCH 3/5] btrfs: fix clone / extent-same deadlocks Date: Tue, 30 Jun 2015 14:42:06 -0700 Message-Id: <1435700528-14141-4-git-send-email-mfasheh@suse.de> X-Mailer: git-send-email 2.1.2 In-Reply-To: <1435700528-14141-1-git-send-email-mfasheh@suse.de> References: <1435700528-14141-1-git-send-email-mfasheh@suse.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 Clone and extent same lock their source and target inodes in opposite order. In addition to this, the range locking in clone doesn't take ordering into account. Fix this by having clone use the same locking helpers as btrfs-extent-same. In addition, I do a small cleanup of the locking helpers, removing a case (both inodes being the same) which was poorly accounted for and never actually used by the callers. Signed-off-by: Mark Fasheh Reviewed-by: David Sterba --- fs/btrfs/ioctl.c | 34 ++++++++-------------------------- 1 file changed, 8 insertions(+), 26 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index b899584..8d6887d 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2831,8 +2831,7 @@ static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2) swap(inode1, inode2); mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT); - if (inode1 != inode2) - mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); + mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); } static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1, @@ -2850,8 +2849,7 @@ static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1, swap(loff1, loff2); } lock_extent_range(inode1, loff1, len); - if (inode1 != inode2) - lock_extent_range(inode2, loff2, len); + lock_extent_range(inode2, loff2, len); } struct cmp_pages { @@ -3713,13 +3711,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, goto out_fput; if (!same_inode) { - if (inode < src) { - mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD); - } else { - mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); - } + btrfs_double_inode_lock(src, inode); } else { mutex_lock(&src->i_mutex); } @@ -3769,8 +3761,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, lock_extent_range(src, lock_start, lock_len); } else { - lock_extent_range(src, off, len); - lock_extent_range(inode, destoff, len); + btrfs_double_extent_lock(src, off, inode, destoff, len); } ret = btrfs_clone(src, inode, off, olen, len, destoff); @@ -3781,9 +3772,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end); } else { - unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1); - unlock_extent(&BTRFS_I(inode)->io_tree, destoff, - destoff + len - 1); + btrfs_double_extent_unlock(src, off, inode, destoff, len); } /* * Truncate page cache pages so that future reads will see the cloned @@ -3792,17 +3781,10 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, truncate_inode_pages_range(&inode->i_data, destoff, PAGE_CACHE_ALIGN(destoff + len) - 1); out_unlock: - if (!same_inode) { - if (inode < src) { - mutex_unlock(&src->i_mutex); - mutex_unlock(&inode->i_mutex); - } else { - mutex_unlock(&inode->i_mutex); - mutex_unlock(&src->i_mutex); - } - } else { + if (!same_inode) + btrfs_double_inode_unlock(src, inode); + else mutex_unlock(&src->i_mutex); - } out_fput: fdput(src_file); out_drop_write: