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drivers: staging: lustre: Track sign separately 

The `mult' parameter is negated if the user data begins with a '-' so
that the final value has the appropriate sign.  But `mult' is only used
if the user data does not include a "units" suffix.  In this case,
`mult' is overridden with the numeric scale conveyed by the units suffix,
but retains the sign of the original value.

Having `mult' serving double-duty works but is confusing.  Use a new
local variable to store the sign of the user data instead.  This also
fixes a pitfall of passing 0 to `mult', expecting it to be ignored when
a units suffix is specified, but having the effect of taking the
absolute value of the user-provided data.

Signed-off-by: Chris Rorvick <chris@rorvick.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chris Rorvick 2014-12-16 22:24:02 -06:00 committed by Greg Kroah-Hartman
parent 965bd8b9f7
commit f56cb9da50
1 changed files with 4 additions and 3 deletions
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7
drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
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@ -1862,6 +1862,7 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
char kernbuf[22], *end, *pbuf;
__u64 whole, frac = 0, units;
unsigned frac_d = 1;
int sign = 1;
if (count > (sizeof(kernbuf) - 1))
return -EINVAL;
@ -1872,7 +1873,7 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
kernbuf[count] = '\0';
pbuf = kernbuf;
if (*pbuf == '-') {
mult = -mult;
sign = -1;
pbuf++;
}
@ -1909,11 +1910,11 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
}
/* Specified units override the multiplier */
if (units > 1)
mult = mult < 0 ? -units : units;
mult = units;
frac *= mult;
do_div(frac, frac_d);
*val = whole * mult + frac;
*val = sign * (whole * mult + frac);
return 0;
}
EXPORT_SYMBOL(lprocfs_write_frac_u64_helper);