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| author | Martin K. Petersen <martin.petersen@oracle.com> | 2010-03-15 12:46:51 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2010-03-15 12:47:59 +0100 |
| commit | 2cda2728aa1c8c006418a24f867b25e5eb7a32e2 (patch) | |
| tree | c23ec7c38d74237646c5453d96bfbbea4cadfee7 /block/blk-settings.c | |
| parent | f11c9c5c259cb2c3d698548dc3936f773ab1f5b9 (diff) | |
| download | lwn-2cda2728aa1c8c006418a24f867b25e5eb7a32e2.tar.gz lwn-2cda2728aa1c8c006418a24f867b25e5eb7a32e2.zip | |
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>
Diffstat (limited to 'block/blk-settings.c')
| -rw-r--r-- | block/blk-settings.c | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 31e7a9375c13..4c4700dca56a 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -8,6 +8,7 @@ #include <linux/blkdev.h> #include <linux/bootmem.h> /* for max_pfn/max_low_pfn */ #include <linux/gcd.h> +#include <linux/lcm.h> #include <linux/jiffies.h> #include "blk.h" @@ -461,16 +462,6 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b) } EXPORT_SYMBOL(blk_queue_stack_limits); -static unsigned int lcm(unsigned int a, unsigned int b) -{ - if (a && b) - return (a * b) / gcd(a, b); - else if (b) - return b; - - return a; -} - /** * blk_stack_limits - adjust queue_limits for stacked devices * @t: the stacking driver limits (top device) |