dm: publish array_too_big

Move array_too_big to include/linux/device-mapper.h because it is
used by targets.

Remove the test from dm-raid1 as the number of mirror legs is limited
such that it can never fail.  (Even for stripes it seems rather
unlikely.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

3 files changed, 2 insertions, 14 deletions

diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 29913e42c4ab..ecfd82169cb3 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1315,9 +1315,6 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
         size_t len;
         struct mirror_set *ms = NULL;
 
-        if (array_too_big(sizeof(*ms), sizeof(ms->mirror[0]), nr_mirrors))
-                return NULL;
-
         len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors);
 
         ms = kzalloc(len, GFP_KERNEL);
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index b745d8ac625b..287e24584730 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -60,8 +60,8 @@ static inline struct stripe_c *alloc_context(unsigned int stripes)
 {
         size_t len;
 
-        if (array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
-                          stripes))
+        if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
+                             stripes))
                 return NULL;
 
         len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes);
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index cd189da2b2fa..0ade60cdef42 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -62,15 +62,6 @@ void dm_put_target_type(struct target_type *t);
 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
                                         void *param), void *param);
 
-/*-----------------------------------------------------------------
- * Useful inlines.
- *---------------------------------------------------------------*/
-static inline int array_too_big(unsigned long fixed, unsigned long obj,
-                                unsigned long num)
-{
-        return (num > (ULONG_MAX - fixed) / obj);
-}
-
 int dm_split_args(int *argc, char ***argvp, char *input);
 
 /*