flex_array: flex_array_prealloc takes a number of elements, not an end

Change flex_array_prealloc to take the number of elements for which space
should be allocated instead of the last (inclusive) element. Users
and documentation are updated accordingly.  flex_arrays got introduced before
they had users.  When folks started using it, they ended up needing a
different API than was coded up originally.  This swaps over to the API that
folks apparently need.

Based-on-patch-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Tested-by: Chris Richards <gizmo@giz-works.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: stable@kernel.org [2.6.38+]
This commit is contained in:
Eric Paris 2011-04-28 15:55:52 -04:00
parent 562abf6241
commit 5a3ea8782c
4 changed files with 14 additions and 11 deletions

View File

@ -66,10 +66,10 @@ trick is to ensure that any needed memory allocations are done before
entering atomic context, using:
int flex_array_prealloc(struct flex_array *array, unsigned int start,
unsigned int end, gfp_t flags);
unsigned int nr_elements, gfp_t flags);
This function will ensure that memory for the elements indexed in the range
defined by start and end has been allocated. Thereafter, a
defined by start and nr_elements has been allocated. Thereafter, a
flex_array_put() call on an element in that range is guaranteed not to
block.

View File

@ -61,7 +61,7 @@ struct flex_array {
struct flex_array *flex_array_alloc(int element_size, unsigned int total,
gfp_t flags);
int flex_array_prealloc(struct flex_array *fa, unsigned int start,
unsigned int end, gfp_t flags);
unsigned int nr_elements, gfp_t flags);
void flex_array_free(struct flex_array *fa);
void flex_array_free_parts(struct flex_array *fa);
int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src,

View File

@ -232,10 +232,10 @@ EXPORT_SYMBOL(flex_array_clear);
/**
* flex_array_prealloc - guarantee that array space exists
* @fa: the flex array for which to preallocate parts
* @start: index of first array element for which space is allocated
* @end: index of last (inclusive) element for which space is allocated
* @flags: page allocation flags
* @fa: the flex array for which to preallocate parts
* @start: index of first array element for which space is allocated
* @nr_elements: number of elements for which space is allocated
* @flags: page allocation flags
*
* This will guarantee that no future calls to flex_array_put()
* will allocate memory. It can be used if you are expecting to
@ -245,13 +245,16 @@ EXPORT_SYMBOL(flex_array_clear);
* Locking must be provided by the caller.
*/
int flex_array_prealloc(struct flex_array *fa, unsigned int start,
unsigned int end, gfp_t flags)
unsigned int nr_elements, gfp_t flags)
{
int start_part;
int end_part;
int part_nr;
unsigned int end;
struct flex_array_part *part;
end = start + nr_elements - 1;
if (start >= fa->total_nr_elements || end >= fa->total_nr_elements)
return -ENOSPC;
if (elements_fit_in_base(fa))

View File

@ -545,7 +545,7 @@ static int policydb_index(struct policydb *p)
goto out;
rc = flex_array_prealloc(p->type_val_to_struct_array, 0,
p->p_types.nprim - 1, GFP_KERNEL | __GFP_ZERO);
p->p_types.nprim, GFP_KERNEL | __GFP_ZERO);
if (rc)
goto out;
@ -562,7 +562,7 @@ static int policydb_index(struct policydb *p)
goto out;
rc = flex_array_prealloc(p->sym_val_to_name[i],
0, p->symtab[i].nprim - 1,
0, p->symtab[i].nprim,
GFP_KERNEL | __GFP_ZERO);
if (rc)
goto out;
@ -2439,7 +2439,7 @@ int policydb_read(struct policydb *p, void *fp)
goto bad;
/* preallocate so we don't have to worry about the put ever failing */
rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim - 1,
rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim,
GFP_KERNEL | __GFP_ZERO);
if (rc)
goto bad;