diff --git a/lib/idr.c b/lib/idr.c index fab2fd5bc326..61383564a6c5 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -231,11 +231,22 @@ void *idr_get_next(struct idr *idr, int *nextid) { struct radix_tree_iter iter; void __rcu **slot; + void *entry = NULL; unsigned long base = idr->idr_base; unsigned long id = *nextid; id = (id < base) ? 0 : id - base; - slot = radix_tree_iter_find(&idr->idr_rt, &iter, id); + radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, id) { + entry = rcu_dereference_raw(*slot); + if (!entry) + continue; + if (!radix_tree_deref_retry(entry)) + break; + if (slot != (void *)&idr->idr_rt.rnode && + entry != (void *)RADIX_TREE_INTERNAL_NODE) + break; + slot = radix_tree_iter_retry(&iter); + } if (!slot) return NULL; id = iter.index + base; @@ -244,7 +255,7 @@ void *idr_get_next(struct idr *idr, int *nextid) return NULL; *nextid = id; - return rcu_dereference_raw(*slot); + return entry; } EXPORT_SYMBOL(idr_get_next); diff --git a/tools/testing/radix-tree/idr-test.c b/tools/testing/radix-tree/idr-test.c index 321ba92c70d2..235eef71f3d1 100644 --- a/tools/testing/radix-tree/idr-test.c +++ b/tools/testing/radix-tree/idr-test.c @@ -227,6 +227,57 @@ void idr_u32_test(int base) idr_u32_test1(&idr, 0xffffffff); } +static inline void *idr_mk_value(unsigned long v) +{ + BUG_ON((long)v < 0); + return (void *)((v & 1) | 2 | (v << 1)); +} + +DEFINE_IDR(find_idr); + +static void *idr_throbber(void *arg) +{ + time_t start = time(NULL); + int id = *(int *)arg; + + rcu_register_thread(); + do { + idr_alloc(&find_idr, idr_mk_value(id), id, id + 1, GFP_KERNEL); + idr_remove(&find_idr, id); + } while (time(NULL) < start + 10); + rcu_unregister_thread(); + + return NULL; +} + +void idr_find_test_1(int anchor_id, int throbber_id) +{ + pthread_t throbber; + time_t start = time(NULL); + + pthread_create(&throbber, NULL, idr_throbber, &throbber_id); + + BUG_ON(idr_alloc(&find_idr, idr_mk_value(anchor_id), anchor_id, + anchor_id + 1, GFP_KERNEL) != anchor_id); + + do { + int id = 0; + void *entry = idr_get_next(&find_idr, &id); + BUG_ON(entry != idr_mk_value(id)); + } while (time(NULL) < start + 11); + + pthread_join(throbber, NULL); + + idr_remove(&find_idr, anchor_id); + BUG_ON(!idr_is_empty(&find_idr)); +} + +void idr_find_test(void) +{ + idr_find_test_1(100000, 0); + idr_find_test_1(0, 100000); +} + void idr_checks(void) { unsigned long i; @@ -307,6 +358,7 @@ void idr_checks(void) idr_u32_test(4); idr_u32_test(1); idr_u32_test(0); + idr_find_test(); } #define module_init(x)