From 5d30b10bd68df007e7ae21e77d1e0ce184b53040 Mon Sep 17 00:00:00 2001 From: Eric Paris <eparis@redhat.com> Date: Thu, 28 Apr 2011 15:55:52 -0400 Subject: [PATCH] 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+] --- 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 cb8a3a00cc9..df904aec990 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 70e4efabe0f..ebeb2f3ad06 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 c0ea40ba208..0c33b24498b 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 e7b850ad57e..e6e7ce0d3d5 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -502,7 +502,7 @@ 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; @@ -519,7 +519,7 @@ 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; @@ -2375,7 +2375,7 @@ 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;