Re: [PATCH v2 1/2] fiemap: Factor out actual fiemap call code

Nikolay Borisov
2017-10-31T20:32:45Z

On 31.10.2017 22:29, Darrick J. Wong wrote:
>> Subject: Re: [PATCH v2 1/2] fiemap: Factor out actual fiemap call code
>
> I thought this was v3....
>
> On Tue, Oct 31, 2017 at 04:10:10PM +0200, Nikolay Borisov wrote:
>> This will be needed to in a subsequent patch to avoid code duplication
>>
>> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
>> ---
>> v2:
>> * Incorporated Daricks feedback - removed variables which weren't introduced
>> until the next patch as a result the build with this patch was broken. This is
>> fixed now
>> io/fiemap.c | 39 ++++++++++++++++++++++++++++-----------
>> 1 file changed, 28 insertions(+), 11 deletions(-)
>>
>> diff --git a/io/fiemap.c b/io/fiemap.c
>> index e6fd66da753d..08391f69d9bd 100644
>> --- a/io/fiemap.c
>> +++ b/io/fiemap.c
>> @@ -211,6 +211,31 @@ calc_print_format(
>> }
>> }
>>
>> +static int
>> +__fiemap(
>> + struct fiemap * fiemap,
>
> struct fiemap *fiemap,
>
>> + int mapsize,
>> + __u32 flags,
>> + __u64 start,
>> + __u64 length) {
>> +
>> + int ret;
>
> int ret;
>
> (Yeah, I know...)
>
>> +
>> + memset(fiemap, 0, mapsize);
>> + fiemap->fm_flags = flags;
>> + fiemap->fm_start = start;
>> + fiemap->fm_length = length;
>> + fiemap->fm_extent_count = EXTENT_BATCH;
>
> It's odd that we pass in both the struct* and its initializers here, but
> we still have to have a way to pass fm_flags and fm_mapped_extents back
> to the __fiemap() caller.
>
> (TBH I'm wondering if this patch is necessary...)

Well,

I'd rather have this function and make the final hole handling in the
next one being a bit more clear, than duplicating the setup + ioctl
statements :)

>
> --D
>
>> + ret = ioctl(file->fd, FS_IOC_FIEMAP, fiemap);
>> + if (ret < 0) {
>> + fprintf(stderr, "%s: ioctl(FS_IOC_FIEMAP) [\"%s\"]: "
>> + "%s\n", progname, file->name, strerror(errno));
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> int
>> fiemap_f(
>> int argc,
>> @@ -266,19 +291,11 @@ fiemap_f(
>>
>> while (!last && (cur_extent != max_extents)) {
>>
>> - memset(fiemap, 0, map_size);
>> - fiemap->fm_flags = fiemap_flags;
>> - fiemap->fm_start = last_logical;
>> - fiemap->fm_length = -1LL;
>> - fiemap->fm_extent_count = EXTENT_BATCH;
>> -
>> - ret = ioctl(file->fd, FS_IOC_FIEMAP, (unsigned long)fiemap);
>> + ret = __fiemap(fiemap, map_size, fiemap_flags, last_logical,
>> + -1LL);
>> if (ret < 0) {
>> - fprintf(stderr, "%s: ioctl(FS_IOC_FIEMAP) [\"%s\"]: "
>> - "%s\n", progname, file->name, strerror(errno));
>> - free(fiemap);
>> exitcode = 1;
>> - return 0;
>> + goto out;
>> }
>>
>> /* No more extents to map, exit */
>> --
>> 2.7.4
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>