diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/idr.c | 36 |
1 files changed, 22 insertions, 14 deletions
diff --git a/lib/idr.c b/lib/idr.c index e0761f7ba7e3..aadc5253d97f 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -39,6 +39,14 @@ static struct kmem_cache *idr_layer_cache; static DEFINE_SPINLOCK(simple_ida_lock); +/* the maximum ID which can be allocated given idr->layers */ +static int idr_max(int layers) +{ + int bits = min_t(int, layers * IDR_BITS, MAX_ID_SHIFT); + + return (1 << bits) - 1; +} + static struct idr_layer *get_from_free_list(struct idr *idp) { struct idr_layer *p; @@ -223,7 +231,7 @@ build_up: * Add a new layer to the top of the tree if the requested * id is larger than the currently allocated space. */ - while ((layers < (MAX_LEVEL - 1)) && (id >= (1 << (layers*IDR_BITS)))) { + while (id > idr_max(layers)) { layers++; if (!p->count) { /* special case: if the tree is currently empty, @@ -265,7 +273,7 @@ build_up: static int idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id) { - struct idr_layer *pa[MAX_LEVEL]; + struct idr_layer *pa[MAX_LEVEL + 1]; int id; id = idr_get_empty_slot(idp, starting_id, pa); @@ -357,7 +365,7 @@ static void idr_remove_warning(int id) static void sub_remove(struct idr *idp, int shift, int id) { struct idr_layer *p = idp->top; - struct idr_layer **pa[MAX_LEVEL]; + struct idr_layer **pa[MAX_LEVEL + 1]; struct idr_layer ***paa = &pa[0]; struct idr_layer *to_free; int n; @@ -451,16 +459,16 @@ void idr_remove_all(struct idr *idp) int n, id, max; int bt_mask; struct idr_layer *p; - struct idr_layer *pa[MAX_LEVEL]; + struct idr_layer *pa[MAX_LEVEL + 1]; struct idr_layer **paa = &pa[0]; n = idp->layers * IDR_BITS; p = idp->top; rcu_assign_pointer(idp->top, NULL); - max = 1 << n; + max = idr_max(idp->layers); id = 0; - while (id < max) { + while (id >= 0 && id <= max) { while (n > IDR_BITS && p) { n -= IDR_BITS; *paa++ = p; @@ -519,7 +527,7 @@ void *idr_find(struct idr *idp, int id) /* Mask off upper bits we don't use for the search. */ id &= MAX_ID_MASK; - if (id >= (1 << n)) + if (id > idr_max(p->layer + 1)) return NULL; BUG_ON(n == 0); @@ -555,15 +563,15 @@ int idr_for_each(struct idr *idp, { int n, id, max, error = 0; struct idr_layer *p; - struct idr_layer *pa[MAX_LEVEL]; + struct idr_layer *pa[MAX_LEVEL + 1]; struct idr_layer **paa = &pa[0]; n = idp->layers * IDR_BITS; p = rcu_dereference_raw(idp->top); - max = 1 << n; + max = idr_max(idp->layers); id = 0; - while (id < max) { + while (id >= 0 && id <= max) { while (n > 0 && p) { n -= IDR_BITS; *paa++ = p; @@ -601,7 +609,7 @@ EXPORT_SYMBOL(idr_for_each); */ void *idr_get_next(struct idr *idp, int *nextidp) { - struct idr_layer *p, *pa[MAX_LEVEL]; + struct idr_layer *p, *pa[MAX_LEVEL + 1]; struct idr_layer **paa = &pa[0]; int id = *nextidp; int n, max; @@ -611,9 +619,9 @@ void *idr_get_next(struct idr *idp, int *nextidp) if (!p) return NULL; n = (p->layer + 1) * IDR_BITS; - max = 1 << n; + max = idr_max(p->layer + 1); - while (id < max) { + while (id >= 0 && id <= max) { while (n > 0 && p) { n -= IDR_BITS; *paa++ = p; @@ -787,7 +795,7 @@ EXPORT_SYMBOL(ida_pre_get); */ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id) { - struct idr_layer *pa[MAX_LEVEL]; + struct idr_layer *pa[MAX_LEVEL + 1]; struct ida_bitmap *bitmap; unsigned long flags; int idr_id = starting_id / IDA_BITMAP_BITS; |