From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:47049 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753119Ab3EZNve (ORCPT ); Sun, 26 May 2013 09:51:34 -0400 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by aserp1040.oracle.com (Sentrion-MTA-4.3.1/Sentrion-MTA-4.3.1) with ESMTP id r4QDpWKW017115 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 26 May 2013 13:51:33 GMT Received: from aserz7022.oracle.com (aserz7022.oracle.com [141.146.126.231]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id r4QDpVVZ009990 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Sun, 26 May 2013 13:51:32 GMT Received: from abhmt101.oracle.com (abhmt101.oracle.com [141.146.116.53]) by aserz7022.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id r4QDpVOQ006799 for ; Sun, 26 May 2013 13:51:31 GMT From: Liu Bo To: linux-btrfs@vger.kernel.org Subject: [PATCH 5/5 RESEND] Btrfs: allow file data clone within a file Date: Sun, 26 May 2013 21:50:31 +0800 Message-Id: <1369576231-17836-6-git-send-email-bo.li.liu@oracle.com> In-Reply-To: <1369576231-17836-1-git-send-email-bo.li.liu@oracle.com> References: <1369576231-17836-1-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: We did not allow file data clone within the same file because of deadlock issues. However, we now use nested lock to avoid deadlock between the parent directory and the child file. So it's safe to do file clone within the same file when the two ranges are not overlapped. Reviewed-by: David Sterba Signed-off-by: Liu Bo --- fs/btrfs/ioctl.c | 26 +++++++++++++++++++------- 1 files changed, 19 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 0f81d67..112153a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2480,6 +2480,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, int ret; u64 len = olen; u64 bs = root->fs_info->sb->s_blocksize; + int same_inode = 0; /* * TODO: @@ -2516,7 +2517,7 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, ret = -EINVAL; if (src == inode) - goto out_fput; + same_inode = 1; /* the src must be open for reading */ if (!(src_file.file->f_mode & FMODE_READ)) @@ -2547,12 +2548,16 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, } path->reada = 2; - if (inode < src) { - mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD); + 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); + } } else { - mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD); + mutex_lock(&src->i_mutex); } /* determine range to clone */ @@ -2570,6 +2575,12 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd, !IS_ALIGNED(destoff, bs)) goto out_unlock; + /* verify if ranges are overlapped within the same file */ + if (same_inode) { + if (destoff + len > off && destoff < off + len) + goto out_unlock; + } + if (destoff > inode->i_size) { ret = btrfs_cont_expand(inode, inode->i_size, destoff); if (ret) @@ -2846,7 +2857,8 @@ out: unlock_extent(&BTRFS_I(src)->io_tree, off, off + len - 1); out_unlock: mutex_unlock(&src->i_mutex); - mutex_unlock(&inode->i_mutex); + if (!same_inode) + mutex_unlock(&inode->i_mutex); vfree(buf); btrfs_free_path(path); out_fput: -- 1.7.7