Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-03 14:49:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-03 14:49:26 -0700
commit57a9d89dc093d86920748fa706fd55f4fcd2399a (patch)
tree9f0e1fe5ffb42713f381739d0140e8ae677375e3
parent567cfea99af61ef19da42f8491da98cf94a4d166 (diff)
parente9637415a92cf25ad800b7fdeddcd30cce7b44ab (diff)
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
-rw-r--r--block/blk-settings.c6
-rw-r--r--include/linux/lcm.h1
-rw-r--r--lib/lcm.c11
3 files changed, 15 insertions, 3 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 6ed2cbe5e8c9..12600bfffca9 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -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;
}
diff --git a/include/linux/lcm.h b/include/linux/lcm.h
index 7bf01d779b45..1ce79a7f1daa 100644
--- a/include/linux/lcm.h
+++ b/include/linux/lcm.h
@@ -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 */
diff --git a/lib/lcm.c b/lib/lcm.c
index e97dbd51e756..03d7fcb420b5 100644
--- a/lib/lcm.c
+++ b/lib/lcm.c
@@ -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);