Jim Meyering wrote:
> Eric Sandeen wrote:
>> https://bugzilla.redhat.com/show_bug.cgi?id=561870
>>
>> # dd if=/dev/zero of=k bs=1MB count=2 seek=20; mkfs.xfs k
>> # mkfs.xfs: probe of k failed, cannot detect existing filesystem.
>> # mkfs.xfs: Use the -f option to force overwrite.
>>
>> blkid fails to do a probe of a regular file.
>>
>> I wish blkid would cope with this, but for now it might
>> be better to just turn it off.
>>
>> Reported-by: Jim Meyering <meyering@xxxxxxxxxx>
>> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
>> ---
>>
>> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
>> index 9baf116..de87647 100644
>> --- a/mkfs/xfs_mkfs.c
>> +++ b/mkfs/xfs_mkfs.c
>> @@ -300,10 +300,15 @@ check_overwrite(
>> int fd;
>> long long size;
>> int bsz;
>> + struct stat statbuf;
>>
>> if (!device || !*device)
>> return 0;
>>
>> + /* blkid can't get info from a regular file */
>> + if (!stat(device, &statbuf) && S_ISREG(statbuf.st_mode))
>> + return 0;
>> +
>> ret = -1; /* will reset on success of all setup calls */
>>
>> fd = open(device, O_RDONLY);
>
> Hi Eric,
>
> Did you consider calling fstat after opening,
> rather than "stat" before?
>
> /* blkid can't get info from a regular file */
> if (!fstat(fd, &statbuf) && S_ISREG(statbuf.st_mode)) {
> close(fd);
> return 0;
> }
>
> That's slightly more efficient, and not prone to confusion
> in the unlikely event that "device" changes inode between
> the stat and the open calls.
Ok, yes that's probably better, will resend. thanks.
-Eric
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