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Date: Wed, 09 Apr 2014 11:19:07 +0800
From: Anand Jain <anand.jain@oracle.com>
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To: Qu Wenruo <quwenruo@cn.fujitsu.com>
CC: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] btrfs-progs: Fix the return value of btrfs_scan_kernel()
References: <1396948562-16653-1-git-send-email-quwenruo@cn.fujitsu.com> <5344ABEB.20906@oracle.com> <5344ADD8.5070301@cn.fujitsu.com>
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On 09/04/2014 10:18, Qu Wenruo wrote:
> Nope, the fix can also deal with no search parameter.

> If any btrfs filesystem can be found and printed, found will be set to 1
> which considered as found,
> then 0 will be returned.

  Oh yes. You are right. Thanks, Anand

> Thanks,
> Qu
> 于 2014年04月09日 10:09, Anand Jain 写道:
>>
>>  I expect btrfs_scan_kernel()  would go away in the long run,
>>  however below fix has a problem - when there is no search item
>>  you would return fail (1) always. Since btrfs_scan_kernel() has
>>  limited usage as you mention as well. So I will leave it to David
>>  to decide.
>>
>> Thanks, Anand
>>
>> On 08/04/2014 17:16, Qu Wenruo wrote:
>>> btrfs_scan_kernel() is only used in 'btrfs fi show' but returns wrong
>>> return value.
>>> When search parameter is passed, it will never return 0 even the search
>>> can be matched.
>>>
>>> This patch will change the whatever strange logic to a more easy to
>>> understand one using 'found' var.
>>>
>>> Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
>>> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
>>> Cc: Anand Jain <anand.jain@oracle.com>
>>> ---
>>>   cmds-filesystem.c | 9 +++------
>>>   1 file changed, 3 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/cmds-filesystem.c b/cmds-filesystem.c
>>> index b81768b..49d3aa7 100644
>>> --- a/cmds-filesystem.c
>>> +++ b/cmds-filesystem.c
>>> @@ -430,6 +430,7 @@ static int btrfs_scan_kernel_v2(void *search)
>>>   static int btrfs_scan_kernel(void *search)
>>>   {
>>>       int ret = 0, fd;
>>> +    int found = 0;
>>>       FILE *f;
>>>       struct mntent *mnt;
>>>       struct btrfs_ioctl_fs_info_args fs_info_arg;
>>> @@ -452,7 +453,6 @@ static int btrfs_scan_kernel(void *search)
>>>
>>>           if (get_label_mounted(mnt->mnt_dir, label)) {
>>>               kfree(dev_info_arg);
>>> -            ret = 1;
>>>               goto out;
>>>           }
>>>           if (search && !match_search_item_kernel(fs_info_arg.fsid,
>>> @@ -467,19 +467,16 @@ static int btrfs_scan_kernel(void *search)
>>>                       space_info_arg, label, mnt->mnt_dir);
>>>               kfree(space_info_arg);
>>>               memset(label, 0, sizeof(label));
>>> +            found = 1;
>>>           }
>>>           if (fd != -1)
>>>               close(fd);
>>>           kfree(dev_info_arg);
>>> -        if (search)
>>> -            ret = 0;
>>>       }
>>> -    if (search)
>>> -        ret = 1;
>>>
>>>   out:
>>>       endmntent(f);
>>> -    return ret;
>>> +    return !found;
>>>   }
>>>
>>>   static int dev_to_fsid(char *dev, __u8 *fsid)
>>>
>
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