diff options
| -rw-r--r-- | include/linux/xarray.h | 9 | ||||
| -rw-r--r-- | lib/test_xarray.c | 21 | ||||
| -rw-r--r-- | lib/xarray.c | 40 |
3 files changed, 70 insertions, 0 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h index b4d70e7568b2..5b7f4ebcf4ff 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -1505,6 +1505,15 @@ void xas_pause(struct xa_state *); void xas_create_range(struct xa_state *); +#ifdef CONFIG_XARRAY_MULTI +int xa_get_order(struct xarray *, unsigned long index); +#else +static inline int xa_get_order(struct xarray *xa, unsigned long index) +{ + return 0; +} +#endif + /** * xas_reload() - Refetch an entry from the xarray. * @xas: XArray operation state. diff --git a/lib/test_xarray.c b/lib/test_xarray.c index d4f97925dbd8..bdd4d7995f79 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -1649,6 +1649,26 @@ static noinline void check_account(struct xarray *xa) #endif } +static noinline void check_get_order(struct xarray *xa) +{ + unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 20 : 1; + unsigned int order; + unsigned long i, j; + + for (i = 0; i < 3; i++) + XA_BUG_ON(xa, xa_get_order(xa, i) != 0); + + for (order = 0; order < max_order; order++) { + for (i = 0; i < 10; i++) { + xa_store_order(xa, i << order, order, + xa_mk_index(i << order), GFP_KERNEL); + for (j = i << order; j < (i + 1) << order; j++) + XA_BUG_ON(xa, xa_get_order(xa, j) != order); + xa_erase(xa, i << order); + } + } +} + static noinline void check_destroy(struct xarray *xa) { unsigned long index; @@ -1697,6 +1717,7 @@ static int xarray_checks(void) check_reserve(&array); check_reserve(&xa0); check_multi_store(&array); + check_get_order(&array); check_xa_alloc(); check_find(&array); check_find_entry(&array); diff --git a/lib/xarray.c b/lib/xarray.c index e9e641d3c0c3..f24cb9a43af8 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -1592,6 +1592,46 @@ unlock: return xas_result(&xas, NULL); } EXPORT_SYMBOL(xa_store_range); + +/** + * xa_get_order() - Get the order of an entry. + * @xa: XArray. + * @index: Index of the entry. + * + * Return: A number between 0 and 63 indicating the order of the entry. + */ +int xa_get_order(struct xarray *xa, unsigned long index) +{ + XA_STATE(xas, xa, index); + void *entry; + int order = 0; + + rcu_read_lock(); + entry = xas_load(&xas); + + if (!entry) + goto unlock; + + if (!xas.xa_node) + goto unlock; + + for (;;) { + unsigned int slot = xas.xa_offset + (1 << order); + + if (slot >= XA_CHUNK_SIZE) + break; + if (!xa_is_sibling(xas.xa_node->slots[slot])) + break; + order++; + } + + order += xas.xa_node->shift; +unlock: + rcu_read_unlock(); + + return order; +} +EXPORT_SYMBOL(xa_get_order); #endif /* CONFIG_XARRAY_MULTI */ /** |