From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:39902 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753414Ab2LLDtz (ORCPT ); Tue, 11 Dec 2012 22:49:55 -0500 Message-ID: <50C7FEF9.6040003@cn.fujitsu.com> Date: Wed, 12 Dec 2012 11:50:17 +0800 From: Miao Xie Reply-To: miaox@cn.fujitsu.com MIME-Version: 1.0 To: Jeff Liu CC: linux-btrfs@vger.kernel.org, anand.jain@oracle.com Subject: Re: [RESEND PATCH V4 1/2] Btrfs: Add a new ioctl to get the label of a mounted filesystem In-Reply-To: <50C7F889.5040103@oracle.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: References: <50C7F889.5040103@oracle.com> On Wed, 12 Dec 2012 11:22:49 +0800, Jeff Liu wrote: > Signed-off-by: Jie Liu > Signed-off-by: Anand Jain > > --- > fs/btrfs/ioctl.c | 14 ++++++++++++++ > fs/btrfs/ioctl.h | 2 ++ > 2 files changed, 16 insertions(+) > > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index 8fcf9a5..b0a5e17 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -3699,6 +3699,18 @@ out: > return ret; > } > > +static int btrfs_ioctl_get_fslabel(struct btrfs_root *root, void __user *arg) > +{ > + const char *label = root->fs_info->super_copy->label; > + int ret; > + > + mutex_lock(&root->fs_info->volume_mutex); > + ret = copy_to_user(arg, label, strlen(label)); > + mutex_unlock(&root->fs_info->volume_mutex); > + > + return ret ? -EFAULT : 0; > +} > + > long btrfs_ioctl(struct file *file, unsigned int > cmd, unsigned long arg) > { > @@ -3797,6 +3809,8 @@ long btrfs_ioctl(struct file *file, unsigned int > return btrfs_ioctl_qgroup_create(root, argp); > case BTRFS_IOC_QGROUP_LIMIT: > return btrfs_ioctl_qgroup_limit(root, argp); > + case BTRFS_IOC_GET_FSLABEL: > + return btrfs_ioctl_get_fslabel(root, argp); > } > > return -ENOTTY; > diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h > index 731e287..98f896f 100644 > --- a/fs/btrfs/ioctl.h > +++ b/fs/btrfs/ioctl.h > @@ -453,4 +453,6 @@ struct btrfs_ioctl_send_args { > struct btrfs_ioctl_qgroup_limit_args) > #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ > struct btrfs_ioctl_get_dev_stats) > +#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 53, \ > + char[BTRFS_LABEL_SIZE]) > #endif > According to the project idea web, https://btrfs.wiki.kernel.org/index.php/Project_ideas#Development_notes.2C_please_read number 53 has been used for the drive swapping commands, so I think we should choose another one. Maybe 49 is good since the above web says number 50 has been reserved for set/change label command.