Re: [PATCH v2 09/14] fsx: add support for -g filldata

[Eryu Guan <eguan@redhat.com>]

On Wed, Aug 30, 2017 at 05:51:41PM +0300, Amir Goldstein wrote:
> -g X: write character X instead of random generated data
> 
> This is useful to compare holes between good and bad buffer.
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>

This seems useful, but I don't see this option gets used in this
patchset. Perhaps introduce it when it gets used in the test?

> ---
>  ltp/fsx.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/ltp/fsx.c b/ltp/fsx.c
> index dd6b637..a75bc55 100644
> --- a/ltp/fsx.c
> +++ b/ltp/fsx.c
> @@ -132,6 +132,7 @@ unsigned long	simulatedopcount = 0;	/* -b flag */
>  int	closeprob = 0;			/* -c flag */
>  int	debug = 0;			/* -d flag */
>  unsigned long	debugstart = 0;		/* -D flag */
> +char	filldata = 0;			/* -g flag */
>  int	logid = 0;			/* -j flag */
>  int	flush = 0;			/* -f flag */
>  int	do_fsync = 0;			/* -y flag */
> @@ -817,6 +818,8 @@ gendata(char *original_buf, char *good_buf, unsigned offset, unsigned size)
>  		good_buf[offset] = testcalls % 256; 
>  		if (offset % 2)
>  			good_buf[offset] += original_buf[offset];
> +		if (filldata)
> +			good_buf[offset] = filldata;

If filldata is not null, we're wasting cycles setting good_buf[offset]
and overwriting it with filldata. Use a if-else switch? e.g.

Thanks,
Eryu

>  		offset++;
>  	}
>  }
> @@ -1631,11 +1634,12 @@ void
>  usage(void)
>  {
>  	fprintf(stdout, "usage: %s",
> -		"fsx [-dnqxAFLOWZ] [-b opnum] [-c Prob] [-i logdev] [-j logid] [-l flen] [-m start:end] [-o oplen] [-p progressinterval] [-r readbdy] [-s style] [-t truncbdy] [-w writebdy] [-D startingop] [-N numops] [-P dirpath] [-S seed] fname\n\
> +		"fsx [-dnqxAFLOWZ] [-b opnum] [-c Prob] [-g filldata] [-i logdev] [-j logid] [-l flen] [-m start:end] [-o oplen] [-p progressinterval] [-r readbdy] [-s style] [-t truncbdy] [-w writebdy] [-D startingop] [-N numops] [-P dirpath] [-S seed] fname\n\
>  	-b opnum: beginning operation number (default 1)\n\
>  	-c P: 1 in P chance of file close+open at each op (default infinity)\n\
>  	-d: debug output for all operations\n\
>  	-f flush and invalidate cache after I/O\n\
> +	-g X: write character X instead of random generated data\n\
>  	-i logdev: do integrity testing, logdev is the dm log writes device\n\
>  	-j logid: prefix logs with this id\n\
>  	-l flen: the upper bound on file size (default 262144)\n\
> @@ -1873,7 +1877,7 @@ main(int argc, char **argv)
>  	setvbuf(stdout, (char *)0, _IOLBF, 0); /* line buffered stdout */
>  
>  	while ((ch = getopt_long(argc, argv,
> -				 "b:c:dfi:j:l:m:no:p:qr:s:t:w:xyAD:FKHzCILN:OP:RS:WZ",
> +				 "b:c:dfg:i:j:l:m:no:p:qr:s:t:w:xyAD:FKHzCILN:OP:RS:WZ",
>  				 longopts, NULL)) != EOF)
>  		switch (ch) {
>  		case 'b':
> @@ -1900,6 +1904,9 @@ main(int argc, char **argv)
>  		case 'f':
>  			flush = 1;
>  			break;
> +		case 'g':
> +			filldata = *optarg;
> +			break;
>  		case 'i':
>  			integrity = 1;
>  			logdev = strdup(optarg);
> -- 
> 2.7.4
>