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Merge branch 'for-linus' of git://git.kernel.dk/linux-block 

Pull block layer fix from Jens Axboe:
 "Just one patch in this pull request, fixing a regression caused by a
  'mathematically correct' change to lcm()"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix blk_stack_limits() regression due to lcm() change
hifive-unleashed-5.1
Linus Torvalds 2015-04-03 14:49:26 -07:00
parent 567cfea99a e9637415a9
commit 57a9d89dc0
3 changed files with 15 additions and 3 deletions
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6
block/blk-settings.c
View File

@ -585,7 +585,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
b->physical_block_size);
t->io_min = max(t->io_min, b->io_min);
t->io_opt = lcm(t->io_opt, b->io_opt);
t->io_opt = lcm_not_zero(t->io_opt, b->io_opt);
t->cluster &= b->cluster;
t->discard_zeroes_data &= b->discard_zeroes_data;
@ -616,7 +616,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
b->raid_partial_stripes_expensive);
/* Find lowest common alignment_offset */
t->alignment_offset = lcm(t->alignment_offset, alignment)
t->alignment_offset = lcm_not_zero(t->alignment_offset, alignment)
% max(t->physical_block_size, t->io_min);
/* Verify that new alignment_offset is on a logical block boundary */
@ -643,7 +643,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
b->max_discard_sectors);
t->discard_granularity = max(t->discard_granularity,
b->discard_granularity);
t->discard_alignment = lcm(t->discard_alignment, alignment) %
t->discard_alignment = lcm_not_zero(t->discard_alignment, alignment) %
t->discard_granularity;
}

1
include/linux/lcm.h
View File

@ -4,5 +4,6 @@
#include <linux/compiler.h>
unsigned long lcm(unsigned long a, unsigned long b) __attribute_const__;
unsigned long lcm_not_zero(unsigned long a, unsigned long b) __attribute_const__;
#endif /* _LCM_H */

11
lib/lcm.c
View File

@ -12,3 +12,14 @@ unsigned long lcm(unsigned long a, unsigned long b)
return 0;
}
EXPORT_SYMBOL_GPL(lcm);
unsigned long lcm_not_zero(unsigned long a, unsigned long b)
{
unsigned long l = lcm(a, b);
if (l)
return l;
return (b ? : a);
}
EXPORT_SYMBOL_GPL(lcm_not_zero);