Re: [LTP] [PATCH v5] statvfs01: Convert to new LTP API

[Avinesh Kumar <akumar@suse.de>]

Hi Petr, Richie,

Thank you for reviewing again and providing more improvement suggestions, I've
made the changes in v6.

Thanks,
Avinesh

On Thursday, December 22, 2022 3:23:35 PM IST Richard Palethorpe wrote:
> Hello,
> 
> Petr Vorel <pvorel@suse.cz> writes:
> 
> > Hi Avinesh, Richie,
> >
> > Generally LGTM, thanks for fixing exfat and vfat.
> >
> >> > +	toolong_fname = SAFE_MALLOC(buf.f_namemax + 1);
> > However, length could be smaller:
> > Instead using buf.f_namemax + 1 (1531) also for exfat and vfat,
> > invalid length is already buf.f_namemax / NLS_MAX_CHARSET_SIZE + 1
> > (256).
> >
> >> > +	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> >> > +		valid_fname = SAFE_MALLOC(buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
> >> > +	else
> >> > +		valid_fname = SAFE_MALLOC(buf.f_namemax - 1);
> 
> There is also a memory leak when running with -I. You could just use an
> 4Kb (PATH_MAX) static buffer as the name. If we find an FS that allows
> longer names then we can increase it.
> 
> We could also use a guarded buffer (specified in tst_test).
> 
> >
> >> > -		if (TEST_RETURN == -1) {
> >> > -			tst_resm(TFAIL | TTERRNO, "statvfs(%s, ...) failed",
> >> > -				 TEST_PATH);
> >> > -		} else {
> >> > -			tst_resm(TPASS, "statvfs(%s, ...) passed", TEST_PATH);
> >> > -		}
> >> > +	memset(toolong_fname, 'b', buf.f_namemax + 1);
> >> > +	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> >> > +		memset(valid_fname, 'a', buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
> >> > +	else
> >> > +		memset(valid_fname, 'a', buf.f_namemax - 1);
> > Also valid length is for buf.f_namemax, not buf.f_namemax - 1. I guess -1 is for
> > \0 (NULL terminator), but tests work even with just buf.f_namemax.
> >
> > Also adding variable to hold the length makes source more readable.
> > How about this?
> >
> > 	struct statvfs buf;
> > 	char *valid_fname, *toolong_fname;
> > 	long fs_type;
> > 	long valid_len;
> >
> > 	fs_type = tst_fs_type(TEST_PATH);
> >
> > 	TST_EXP_PASS(statvfs(TEST_PATH, &buf));
> >
> > 	valid_len = buf.f_namemax;
> > 	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> > 		valid_len = buf.f_namemax / NLS_MAX_CHARSET_SIZE;
> >
> > 	valid_fname = SAFE_MALLOC(valid_len);
> > 	memset(valid_fname, 'a', valid_len);
> >
> > 	toolong_fname = SAFE_MALLOC(valid_len + 1);
> > 	memset(toolong_fname, 'b', valid_len + 1);
> >
> > Final diff is below.
> >
> > Kind regards,
> > Petr
> >
> > diff --git testcases/kernel/syscalls/statvfs/statvfs01.c testcases/kernel/syscalls/statvfs/statvfs01.c
> > index 034835da7d..f357855eb1 100644
> > --- testcases/kernel/syscalls/statvfs/statvfs01.c
> > +++ testcases/kernel/syscalls/statvfs/statvfs01.c
> > @@ -25,22 +25,21 @@ static void run(void)
> >  	struct statvfs buf;
> >  	char *valid_fname, *toolong_fname;
> >  	long fs_type;
> > +	long valid_len;
> >  
> >  	fs_type = tst_fs_type(TEST_PATH);
> >  
> >  	TST_EXP_PASS(statvfs(TEST_PATH, &buf));
> >  
> > -	toolong_fname = SAFE_MALLOC(buf.f_namemax + 1);
> > +	valid_len = buf.f_namemax;
> >  	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> > -		valid_fname = SAFE_MALLOC(buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
> > -	else
> > -		valid_fname = SAFE_MALLOC(buf.f_namemax - 1);
> > +		valid_len = buf.f_namemax / NLS_MAX_CHARSET_SIZE;
> >  
> > -	memset(toolong_fname, 'b', buf.f_namemax + 1);
> > -	if (fs_type == TST_VFAT_MAGIC || fs_type == TST_EXFAT_MAGIC)
> > -		memset(valid_fname, 'a', buf.f_namemax / NLS_MAX_CHARSET_SIZE - 1);
> > -	else
> > -		memset(valid_fname, 'a', buf.f_namemax - 1);
> > +	valid_fname = SAFE_MALLOC(valid_len);
> > +	memset(valid_fname, 'a', valid_len);
> > +
> > +	toolong_fname = SAFE_MALLOC(valid_len + 1);
> > +	memset(toolong_fname, 'b', valid_len + 1);
> >  
> >  	TST_EXP_FD(creat(valid_fname, 0444));
> >  	SAFE_CLOSE(TST_RET);
> 
> 
> 





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