[PATCH 1/3] flex_array: flex_array_prealloc takes a number ofelements, not an end

From: Eric Paris
Date: Mon Apr 25 2011 - 21:46:09 EST


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.

Based-on-patch-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
---

Documentation/flexible-arrays.txt | 4 ++--
include/linux/flex_array.h | 2 +-
lib/flex_array.c | 13 ++++++++-----
security/selinux/ss/policydb.c | 6 +++---
4 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/Documentation/flexible-arrays.txt b/Documentation/flexible-arrays.txt
index cb8a3a0..df904ae 100644
--- a/Documentation/flexible-arrays.txt
+++ b/Documentation/flexible-arrays.txt
@@ -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.

diff --git a/include/linux/flex_array.h b/include/linux/flex_array.h
index 70e4efa..ebeb2f3 100644
--- a/include/linux/flex_array.h
+++ b/include/linux/flex_array.h
@@ -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,
diff --git a/lib/flex_array.c b/lib/flex_array.c
index c0ea40b..0c33b24 100644
--- a/lib/flex_array.c
+++ b/lib/flex_array.c
@@ -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))
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 3258799..1b150d7 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -551,7 +551,7 @@ 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;

@@ -568,7 +568,7 @@ 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;
@@ -2445,7 +2445,7 @@ 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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