diff mbox

Btrfs: cleanup redundant code in __btrfs_close_devices()

Message ID 1378570511-20990-1-git-send-email-a3at.mail@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Azat Khuzhin Sept. 7, 2013, 4:15 p.m. UTC
Signed-off-by: Azat Khuzhin <a3at.mail@gmail.com>
---
 fs/btrfs/volumes.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Azat Khuzhin Sept. 10, 2013, 11:39 a.m. UTC | #1
On Mon, Sep 9, 2013 at 7:28 AM, Wang Shilong <wangsl.fnst@cn.fujitsu.com> wrote:
> On 09/08/2013 12:15 AM, Azat Khuzhin wrote:
>>
>> Signed-off-by: Azat Khuzhin <a3at.mail@gmail.com>
>> ---
>>   fs/btrfs/volumes.c |    2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>> index 1d1b595..124228e 100644
>> --- a/fs/btrfs/volumes.c
>> +++ b/fs/btrfs/volumes.c
>> @@ -644,7 +644,7 @@ static int __btrfs_close_devices(struct
>> btrfs_fs_devices *fs_devices)
>>                 /* Safe because we are under uuid_mutex */
>>                 if (device->name) {
>>                         name = rcu_string_strdup(device->name->str,
>> GFP_NOFS);
>> -                       BUG_ON(device->name && !name); /* -ENOMEM */
>> +                       BUG_ON(!name); /* -ENOMEM *
>
> Nice catch! out of memory should not trigger BUG_ON()..
> Maybe we can handle it gracefully.

Maybe return -ENOMEM ?

>
> Thanks,
> Wang
>
>>                         rcu_assign_pointer(new_device->name, name);
>>                 }
>>                 new_device->bdev = NULL;
>
>
Wang Shilong Sept. 10, 2013, 1:15 p.m. UTC | #2
> On Mon, Sep 9, 2013 at 7:28 AM, Wang Shilong <wangsl.fnst@cn.fujitsu.com> wrote:
>> On 09/08/2013 12:15 AM, Azat Khuzhin wrote:
>>> 
>>> Signed-off-by: Azat Khuzhin <a3at.mail@gmail.com>
>>> ---
>>>  fs/btrfs/volumes.c |    2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>> 
>>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>>> index 1d1b595..124228e 100644
>>> --- a/fs/btrfs/volumes.c
>>> +++ b/fs/btrfs/volumes.c
>>> @@ -644,7 +644,7 @@ static int __btrfs_close_devices(struct
>>> btrfs_fs_devices *fs_devices)
>>>                /* Safe because we are under uuid_mutex */
>>>                if (device->name) {
>>>                        name = rcu_string_strdup(device->name->str,
>>> GFP_NOFS);
>>> -                       BUG_ON(device->name && !name); /* -ENOMEM */
>>> +                       BUG_ON(!name); /* -ENOMEM *
>> 
>> Nice catch! out of memory should not trigger BUG_ON()..
>> Maybe we can handle it gracefully.
> 
> Maybe return -ENOMEM ?

Yeah, BUG_On is really unfriendly. And here ENOMEM triggers
BUG_ON() is a lazy approach.

I think we can  return -ENOMEM rather than BUG_ON(), the caller can handle this.

Thanks,
Wang
> 
>> 
>> Thanks,
>> Wang
>> 
>>>                        rcu_assign_pointer(new_device->name, name);
>>>                }
>>>                new_device->bdev = NULL;
>> 
>> 
> 
> 
> 
> -- 
> Respectfully
> Azat Khuzhin
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Azat Khuzhin Sept. 10, 2013, 8:40 p.m. UTC | #3
On Tue, Sep 10, 2013 at 5:15 PM, Wang Shilong <wangshilong1991@gmail.com> wrote:
>> On Mon, Sep 9, 2013 at 7:28 AM, Wang Shilong <wangsl.fnst@cn.fujitsu.com> wrote:
>>> On 09/08/2013 12:15 AM, Azat Khuzhin wrote:
>>>>
>>>> Signed-off-by: Azat Khuzhin <a3at.mail@gmail.com>
>>>> ---
>>>>  fs/btrfs/volumes.c |    2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>>>> index 1d1b595..124228e 100644
>>>> --- a/fs/btrfs/volumes.c
>>>> +++ b/fs/btrfs/volumes.c
>>>> @@ -644,7 +644,7 @@ static int __btrfs_close_devices(struct
>>>> btrfs_fs_devices *fs_devices)
>>>>                /* Safe because we are under uuid_mutex */
>>>>                if (device->name) {
>>>>                        name = rcu_string_strdup(device->name->str,
>>>> GFP_NOFS);
>>>> -                       BUG_ON(device->name && !name); /* -ENOMEM */
>>>> +                       BUG_ON(!name); /* -ENOMEM *
>>>
>>> Nice catch! out of memory should not trigger BUG_ON()..
>>> Maybe we can handle it gracefully.
>>
>> Maybe return -ENOMEM ?
>
> Yeah, BUG_On is really unfriendly. And here ENOMEM triggers
> BUG_ON() is a lazy approach.
>
> I think we can  return -ENOMEM rather than BUG_ON(), the caller can handle this.

I will write a patch, when this one will be merged, to avoid conflicts,
and also because the issue that this patch solves is different from BUG_ON().

>
> Thanks,
> Wang
>>
>>>
>>> Thanks,
>>> Wang
>>>
>>>>                        rcu_assign_pointer(new_device->name, name);
>>>>                }
>>>>                new_device->bdev = NULL;
>>>
>>>
>>
>>
>>
>> --
>> Respectfully
>> Azat Khuzhin
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
diff mbox

Patch

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1d1b595..124228e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -644,7 +644,7 @@  static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 		/* Safe because we are under uuid_mutex */
 		if (device->name) {
 			name = rcu_string_strdup(device->name->str, GFP_NOFS);
-			BUG_ON(device->name && !name); /* -ENOMEM */
+			BUG_ON(!name); /* -ENOMEM */
 			rcu_assign_pointer(new_device->name, name);
 		}
 		new_device->bdev = NULL;