31 Mar, 2015

1 commit

• e9637415a   block: fix blk_stack_limits() regression due to lcm() change ... Browse Code »

  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

  Mike Snitzer

  2015-03-31 23:45:50 +0800  

13 Feb, 2015

1 commit

• 6016daed5   lib/lcm.c: replace include ... Browse Code »

  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

  Rasmus Villemoes

  2015-02-13 10:54:16 +0800  

11 Dec, 2014

2 commits

• 69c953c85   lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n ... Browse Code »

  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

  Rasmus Villemoes

  2014-12-11 09:41:11 +0800  
• 74a5fef7c   lib/lcm.c: ensure correct result whenever it fits ... Browse Code »

  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

  Rasmus Villemoes

  2014-12-11 09:41:11 +0800  

08 Mar, 2012

1 commit

• 8bc3bcc93   lib: reduce the use of module.h wherever possible ... Browse Code »

  43

  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

  2012-03-08 04:04:04 +0800  

26 Jul, 2011

1 commit

• 72d39508e   lib/lcm.c: quiet sparse noise ... Browse Code »

  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

  H Hartley Sweeten

  2011-07-26 11:57:15 +0800  

15 Mar, 2010

1 commit

• 2cda2728a   block: Fix overrun in lcm() and move it to lib ... Browse Code »

  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

  Martin K. Petersen

  2010-03-15 19:47:59 +0800