31 Mar, 2015
1 commit
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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
0After this fix:
$ cat /sys/block/dm-5/queue/optimal_io_size
786432Signed-off-by: Mike Snitzer
Cc: stable@vger.kernel.org # 3.19+
Acked-by: Martin K. Petersen
Signed-off-by: Jens Axboe
13 Feb, 2015
1 commit
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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
11 Dec, 2014
2 commits
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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 -
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
08 Mar, 2012
1 commit
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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
26 Jul, 2011
1 commit
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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
15 Mar, 2010
1 commit
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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