Commit 5a3ea878 authored by Eric Paris's avatar Eric Paris
Browse files

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: default avatarSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
Tested-by: default avatarChris Richards <gizmo@giz-works.com>
Acked-by: default avatarDave Hansen <dave@linux.vnet.ibm.com>
Cc: stable@kernel.org [2.6.38+]
parent 562abf62

Documentation/flexible-arrays.txt

+2 −2
Original line number Diff line number Diff line
@@ -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.

include/linux/flex_array.h

+1 −1
Original line number Diff line number Diff line
@@ -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,

lib/flex_array.c

+8 −5
Original line number Diff line number Diff line
@@ -234,7 +234,7 @@ 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

 * @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()
@@ -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))

security/selinux/ss/policydb.c

+3 −3
Original line number Diff line number Diff line
@@ -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;

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