diff mbox

[V4,2/2] Btrfs: Add a new ioctl to change the label of a mounted filesystem

Message ID 50C7CE44.3010405@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

jeff.liu Dec. 12, 2012, 12:22 a.m. UTC 
Add a new ioctl BTRFS_FS_SETLABEL to change the label of a mounted filesystem.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>

---
 fs/btrfs/ioctl.c |   14 ++++++++++++++
 fs/btrfs/ioctl.h |    2 ++
 2 files changed, 16 insertions(+)

Comments

Miao Xie Dec. 12, 2012, 3:03 a.m. UTC | #1 
Hi, Liu

On wed, 12 Dec 2012 08:22:28 +0800, Jeff Liu wrote:
> Add a new ioctl BTRFS_FS_SETLABEL to change the label of a mounted filesystem.
> 
> Signed-off-by: Jie Liu <jeff.liu@oracle.com>
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> 
> ---
>  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;
> +}


You sent out a wrong patch.

Thanks
Miao

> +
>  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
> 

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jeff.liu Dec. 12, 2012, 3:17 a.m. UTC | #2 
Hi Miao,

On 12/12/2012 11:03 AM, Miao Xie wrote:
> Hi, Liu
> 
> On wed, 12 Dec 2012 08:22:28 +0800, Jeff Liu wrote:
>> Add a new ioctl BTRFS_FS_SETLABEL to change the label of a mounted filesystem.
>>
>> Signed-off-by: Jie Liu <jeff.liu@oracle.com>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>>
>> ---
>>  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;
>> +}
> 
> 
> You sent out a wrong patch.
Ah! I should not send patches out during my sleepy state, will re-send
them a little while, thank you. :)

-Jeff
> 
> Thanks
> Miao
> 
>> +
>>  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
>>
> 

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diff mbox

Patch

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
-- 
1.7.9.5

jeff@koala:/usr/src/linux$ cat btrfs_label_v3/0002-set-label.patch 
Signed-off-by: Jie Liu <jeff.liu@oracle.com>

---
 fs/btrfs/ioctl.c |   34 ++++++++++++++++++++++++++++++++++
 fs/btrfs/ioctl.h |    2 ++
 2 files changed, 36 insertions(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index b0a5e17..ebbf634 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3711,6 +3711,38 @@  static int btrfs_ioctl_get_fslabel(struct btrfs_root *root, void __user *arg)
 	return ret ? -EFAULT : 0;
 }
 
+static int btrfs_ioctl_set_fslabel(struct btrfs_root *root, void __user *arg)
+{
+	struct btrfs_super_block *super_block = root->fs_info->super_copy;
+	struct btrfs_trans_handle *trans;
+	char label[BTRFS_LABEL_SIZE];
+	int ret = 0;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (btrfs_root_readonly(root))
+		return -EROFS;
+
+	if (copy_from_user(label, arg, sizeof(label)))
+		return -EFAULT;
+
+	label[BTRFS_LABEL_SIZE - 1] = '\0';
+
+	mutex_lock(&root->fs_info->volume_mutex);
+	trans = btrfs_start_transaction(root, 1);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		goto out_unlock;
+	}
+	strcpy(super_block->label, label);
+	btrfs_end_transaction(trans, root);
+
+out_unlock:
+	mutex_unlock(&root->fs_info->volume_mutex);
+	return ret;
+}
+
 long btrfs_ioctl(struct file *file, unsigned int
 		cmd, unsigned long arg)
 {
@@ -3811,6 +3843,8 @@  long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_qgroup_limit(root, argp);
 	case BTRFS_IOC_GET_FSLABEL:
 		return btrfs_ioctl_get_fslabel(root, argp);
+	case BTRFS_IOC_SET_FSLABEL:
+		return btrfs_ioctl_set_fslabel(root, argp);
 	}
 
 	return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 98f896f..cc4e657 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -455,4 +455,6 @@  struct btrfs_ioctl_send_args {
 				      struct btrfs_ioctl_get_dev_stats)
 #define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 53, \
 				   char[BTRFS_LABEL_SIZE])
+#define BTRFS_IOC_SET_FSLABEL _IOW(BTRFS_IOCTL_MAGIC, 54, \
+				   char[BTRFS_LABEL_SIZE])
 #endif