Commit 5d30b10bd68df007e7ae21e77d1e0ce184b53040

Authored by Eric Paris
1 parent cb1e922fa1

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+]

Showing 4 changed files with 14 additions and 11 deletions Side-by-side Diff

Documentation/flexible-arrays.txt
... ... @@ -66,10 +66,10 @@
66 66 entering atomic context, using:
67 67  
68 68 int flex_array_prealloc(struct flex_array *array, unsigned int start,
69   - unsigned int end, gfp_t flags);
  69 + unsigned int nr_elements, gfp_t flags);
70 70  
71 71 This function will ensure that memory for the elements indexed in the range
72   -defined by start and end has been allocated. Thereafter, a
  72 +defined by start and nr_elements has been allocated. Thereafter, a
73 73 flex_array_put() call on an element in that range is guaranteed not to
74 74 block.
75 75  
include/linux/flex_array.h
... ... @@ -61,7 +61,7 @@
61 61 struct flex_array *flex_array_alloc(int element_size, unsigned int total,
62 62 gfp_t flags);
63 63 int flex_array_prealloc(struct flex_array *fa, unsigned int start,
64   - unsigned int end, gfp_t flags);
  64 + unsigned int nr_elements, gfp_t flags);
65 65 void flex_array_free(struct flex_array *fa);
66 66 void flex_array_free_parts(struct flex_array *fa);
67 67 int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src,
... ... @@ -232,10 +232,10 @@
232 232  
233 233 /**
234 234 * flex_array_prealloc - guarantee that array space exists
235   - * @fa: the flex array for which to preallocate parts
236   - * @start: index of first array element for which space is allocated
237   - * @end: index of last (inclusive) element for which space is allocated
238   - * @flags: page allocation flags
  235 + * @fa: the flex array for which to preallocate parts
  236 + * @start: index of first array element for which space is allocated
  237 + * @nr_elements: number of elements for which space is allocated
  238 + * @flags: page allocation flags
239 239 *
240 240 * This will guarantee that no future calls to flex_array_put()
241 241 * will allocate memory. It can be used if you are expecting to
242 242  
243 243  
... ... @@ -245,12 +245,15 @@
245 245 * Locking must be provided by the caller.
246 246 */
247 247 int flex_array_prealloc(struct flex_array *fa, unsigned int start,
248   - unsigned int end, gfp_t flags)
  248 + unsigned int nr_elements, gfp_t flags)
249 249 {
250 250 int start_part;
251 251 int end_part;
252 252 int part_nr;
  253 + unsigned int end;
253 254 struct flex_array_part *part;
  255 +
  256 + end = start + nr_elements - 1;
254 257  
255 258 if (start >= fa->total_nr_elements || end >= fa->total_nr_elements)
256 259 return -ENOSPC;
security/selinux/ss/policydb.c
... ... @@ -502,7 +502,7 @@
502 502 goto out;
503 503  
504 504 rc = flex_array_prealloc(p->type_val_to_struct_array, 0,
505   - p->p_types.nprim - 1, GFP_KERNEL | __GFP_ZERO);
  505 + p->p_types.nprim, GFP_KERNEL | __GFP_ZERO);
506 506 if (rc)
507 507 goto out;
508 508  
... ... @@ -519,7 +519,7 @@
519 519 goto out;
520 520  
521 521 rc = flex_array_prealloc(p->sym_val_to_name[i],
522   - 0, p->symtab[i].nprim - 1,
  522 + 0, p->symtab[i].nprim,
523 523 GFP_KERNEL | __GFP_ZERO);
524 524 if (rc)
525 525 goto out;
... ... @@ -2375,7 +2375,7 @@
2375 2375 goto bad;
2376 2376  
2377 2377 /* preallocate so we don't have to worry about the put ever failing */
2378   - rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim - 1,
  2378 + rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim,
2379 2379 GFP_KERNEL | __GFP_ZERO);
2380 2380 if (rc)
2381 2381 goto bad;