Re: [PATCH 4/6] btrfs-progs: mkfs.c overwrites fd without appropriate close

[Anand Jain <Anand.Jain@oracle.com>]

On 08/14/2013 10:04 AM, Anand Jain wrote:
>
>
> On 08/14/2013 03:14 AM, Josef Bacik wrote:
>> On Fri, Jul 26, 2013 at 01:35:28AM +0800, Anand Jain wrote:
>>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>>> ---
>>>   mkfs.c |    3 ++-
>>>   1 files changed, 2 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/mkfs.c b/mkfs.c
>>> index 60f906c..66f558a 100644
>>> --- a/mkfs.c
>>> +++ b/mkfs.c
>>> @@ -1570,6 +1570,8 @@ int main(int ac, char **av)
>>>            * occur by the following processing.
>>>            * (btrfs_register_one_device() fails if O_EXCL is on)
>>>            */
>>> +        if (fd > 0)
>>> +            close(fd);
>>>           fd = open(file, O_RDWR);
>>>           if (fd < 0) {
>>>               fprintf(stderr, "unable to open %s: %s\n", file,
>>> @@ -1581,7 +1583,6 @@ int main(int ac, char **av)
>>>           if (ret) {
>>>               fprintf(stderr, "skipping duplicate device %s in FS\n",
>>>                   file);
>>> -            close(fd);
>>>               continue;
>>>           }
>>>           ret = btrfs_prepare_device(fd, file, zero_end,
>>> &dev_block_count,
>>
>> This breaks mkfs with multiple disks.
>
>   I can't believe as I have been playing with multiple disks
>   quite a lot recently. let me dig more.

  Sorry my mistake.

  Indeed further down btrfs_add_to_fsid() stores fd. closing a
  stored fd is not correct theoretically.

  Josef, Would be keen to know which xfstest caught this. ?

  I am sending a patch to back out this, to be applied on the
  current integration branch if it helps users for the time being.

Thanks, Anand