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

Anand Jain
Thu, 30 Aug 2012 05:44:26 -0000

Jeff,

  I don''t find the get label ioctl part unless I am missing something.
  Any idea?

Thxs, -Anand


On 30/08/12 09:54, Anand Jain wrote:
>
> 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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