Commit graph

5 commits

Author SHA1 Message Date
Rasmus Villemoes
69c953c85c lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n
Return the mathematically correct answer when an argument is 0.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:11 -08:00
Rasmus Villemoes
74a5fef7cb lib/lcm.c: ensure correct result whenever it fits
Ensure that lcm(a,b) returns the mathematically correct result, provided
it fits in an unsigned long.  The current version returns garbage if a*b
overflows, even if the final result would fit.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-10 17:41:11 -08:00
Paul Gortmaker
8bc3bcc93a lib: reduce the use of module.h wherever possible
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include.  Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-03-07 15:04:04 -05:00
H Hartley Sweeten
72d39508e4 lib/lcm.c: quiet sparse noise
The symbol 'lcm' is exported to the kernel (EXPORT_SYMBOL_GPL).
Pick up it's definition in <linux/lcm.h> to quiet the sparse noise:

  warning: symbol 'lcm' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:15 -07:00
Martin K. Petersen
2cda2728aa block: Fix overrun in lcm() and move it to lib
lcm() was defined to take integer-sized arguments.  The supplied
arguments are multiplied, however, causing us to overflow given
sufficiently large input.  That in turn led to incorrect optimal I/O
size reporting in some cases (RAID over RAID).

Switch lcm() over to unsigned long similar to gcd() and move the
function from blk-settings.c to lib.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-03-15 12:47:59 +01:00