Re: [PATCH] Btrfs: Add get/set label ioctl

Anand Jain
Thu, 30 Aug 2012 01:54:56 -0000

Ah. I missed that. Thanks.
  So should use your original patch.

-Anand

On 29/08/12 17:00, Jie Liu wrote:
> Hi Anand,
>
> I have posted a patch for set label back to last year, which can be
> found at:
> https://patchwork.kernel.org/patch/1124642/
>
> Besides that,  we have discussed to use 50 as the ioctl(2) number at
> that time.
>
> task assignment in our wiki page:
>
https://btrfs.wiki.kernel.org/index.php/Project_ideas#Set.2Fchange_file_system_label
>
> Thanks,
> -Jeff
>
> On 08/29/12 16:46, Anand jain wrote:
>> From: Anand Jain<anand.jain@oracle.com>
>>
>> Signed-off-by: Anand Jain<anand.jain@oracle.com>
>> ---
>>   fs/btrfs/ctree.h |   10 ++++++++++
>>   fs/btrfs/ioctl.c |   30 ++++++++++++++++++++++++++++++
>>   fs/btrfs/ioctl.h |    2 ++
>>   3 files changed, 42 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
>> index 4bab807..eff506f 100644
>> --- a/fs/btrfs/ctree.h
>> +++ b/fs/btrfs/ctree.h
>> @@ -2583,6 +2583,16 @@ BTRFS_SETGET_STACK_FUNCS(super_csum_type, struct
btrfs_super_block,
>>   BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct
btrfs_super_block,
>>   			 cache_generation, 64);
>>
>> +static inline char * btrfs_super_label(struct btrfs_super_block *s)
>> +{
>> +	return s->label;
>> +}
>> +static inline void btrfs_set_super_label(struct btrfs_super_block *s,
>> +	char *val)
>> +{
>> +	memcpy(s->label,val,BTRFS_LABEL_SIZE);
>> +}
>> +
>>   static inline int btrfs_super_csum_size(struct btrfs_super_block *s)
>>   {
>>   	int t = btrfs_super_csum_type(s);
>> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
>> index 7bb7556..b472942 100644
>> --- a/fs/btrfs/ioctl.c
>> +++ b/fs/btrfs/ioctl.c
>> @@ -3687,6 +3687,32 @@ out:
>>   	return ret;
>>   }
>>
>> +static int btrfs_ioctl_get_label(struct btrfs_root *root, void __user
*arg)
>> +{
>> +	char *label;
>> +	label = btrfs_super_label(root->fs_info->super_copy);
>> +	if (copy_to_user(arg, label, BTRFS_LABEL_SIZE))
>> +		return -EFAULT;
>> +	return 0;
>> +}
>> +
>> +static int btrfs_ioctl_set_label(struct btrfs_root *root, void __user
*arg)
>> +{
>> +	struct btrfs_trans_handle *trans;
>> +	char label[BTRFS_LABEL_SIZE+1];
>> +
>> +	if (!capable(CAP_SYS_ADMIN))
>> +		return -EPERM;
>> +	if (copy_from_user(label, arg, BTRFS_LABEL_SIZE))
>> +		return -EFAULT;
>> +	label[BTRFS_LABEL_SIZE] = ''\0'';
>> +	trans = btrfs_start_transaction(root, 1);
>> +	btrfs_set_super_label(root->fs_info->super_copy, label);
>> +	btrfs_commit_transaction(trans, root);
>> +
>> +	return 0;
>> +}
>> +
>>   long btrfs_ioctl(struct file *file, unsigned int
>>   		cmd, unsigned long arg)
>>   {
>> @@ -3785,6 +3811,10 @@ 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_LABEL:
>> +		return btrfs_ioctl_get_label(root, argp);
>> +	case BTRFS_IOC_SET_LABEL:
>> +		return btrfs_ioctl_set_label(root, argp);
>>   	}
>>
>>   	return -ENOTTY;
>> diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
>> index 731e287..0c60fcb 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_LABEL _IOR(BTRFS_IOCTL_MAGIC, 53, __u64)
>> +#define BTRFS_IOC_SET_LABEL _IOW(BTRFS_IOCTL_MAGIC, 54, __u64)
>>   #endif
>
>
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