user/sven/linux.git/lib/lcm.c, branch v4.4.2

block: fix blk_stack_limits() regression due to lcm() change

2015-03-31T15:45:50Z

Linux 3.19 commit 69c953c ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n") caused blk_stack_limits() to not properly stack queue_limits for stacked devices (e.g. DM). Fix this regression by establishing lcm_not_zero() and switching blk_stack_limits() over to using it. DM uses blk_set_stacking_limits() to establish the initial top-level queue_limits that are then built up based on underlying devices' limits using blk_stack_limits(). In the case of optimal_io_size (io_opt) blk_set_stacking_limits() establishes a default value of 0. With commit 69c953c, lcm(0, n) is no longer n, which compromises proper stacking of the underlying devices' io_opt. Test: $ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536 $ cat /sys/block/sde/queue/optimal_io_size 786432 $ dmsetup create node --table "0 100 linear /dev/sde 0" Before this fix: $ cat /sys/block/dm-5/queue/optimal_io_size 0 After this fix: $ cat /sys/block/dm-5/queue/optimal_io_size 786432 Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # 3.19+ Acked-by: Martin K. Petersen Signed-off-by: Jens Axboe

lib/lcm.c: replace include

2015-02-13T02:54:16Z

We don't need all the stuff kernel.h pulls in; just compiler.h since export.h doesn't do necessary #includes. This removes more than 100 dependencies. Signed-off-by: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n

2014-12-11T01:41:11Z

Return the mathematically correct answer when an argument is 0. Signed-off-by: Rasmus Villemoes Cc: Martin K. Petersen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/lcm.c: ensure correct result whenever it fits

2014-12-11T01:41:11Z

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 Cc: Martin K. Petersen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib: reduce the use of module.h wherever possible

2012-03-07T20:04:04Z

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

lib/lcm.c: quiet sparse noise

2011-07-26T03:57:15Z

The symbol 'lcm' is exported to the kernel (EXPORT_SYMBOL_GPL). Pick up it's definition in to quiet the sparse noise: warning: symbol 'lcm' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

block: Fix overrun in lcm() and move it to lib

2010-03-15T11:47:59Z

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 Signed-off-by: Jens Axboe