diff options
| -rw-r--r-- | include/linux/xarray.h | 147 | ||||
| -rw-r--r-- | lib/radix-tree.c | 4 | ||||
| -rw-r--r-- | lib/test_xarray.c | 177 | ||||
| -rw-r--r-- | lib/xarray.c | 693 | ||||
| -rw-r--r-- | tools/include/linux/bitmap.h | 1 | ||||
| -rw-r--r-- | tools/include/linux/spinlock.h | 2 | ||||
| -rw-r--r-- | tools/testing/radix-tree/Makefile | 2 | ||||
| -rw-r--r-- | tools/testing/radix-tree/bitmap.c | 23 | ||||
| -rw-r--r-- | tools/testing/radix-tree/linux/kernel.h | 4 | ||||
| -rw-r--r-- | tools/testing/radix-tree/linux/lockdep.h | 11 |
10 files changed, 1055 insertions, 9 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 2de504ae9ba4..15eab63286ed 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -205,10 +205,17 @@ typedef unsigned __bitwise xa_mark_t; #define XA_PRESENT ((__force xa_mark_t)8U) #define XA_MARK_MAX XA_MARK_2 +enum xa_lock_type { + XA_LOCK_IRQ = 1, + XA_LOCK_BH = 2, +}; + /* * Values for xa_flags. The radix tree stores its GFP flags in the xa_flags, * and we remain compatible with that. */ +#define XA_FLAGS_LOCK_IRQ ((__force gfp_t)XA_LOCK_IRQ) +#define XA_FLAGS_LOCK_BH ((__force gfp_t)XA_LOCK_BH) #define XA_FLAGS_MARK(mark) ((__force gfp_t)((1U << __GFP_BITS_SHIFT) << \ (__force unsigned)(mark))) @@ -267,6 +274,7 @@ struct xarray { void xa_init_flags(struct xarray *, gfp_t flags); void *xa_load(struct xarray *, unsigned long index); +void *xa_store(struct xarray *, unsigned long index, void *entry, gfp_t); bool xa_get_mark(struct xarray *, unsigned long index, xa_mark_t); void xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); void xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); @@ -309,6 +317,23 @@ static inline bool xa_marked(const struct xarray *xa, xa_mark_t mark) return xa->xa_flags & XA_FLAGS_MARK(mark); } +/** + * xa_erase() - Erase this entry from the XArray. + * @xa: XArray. + * @index: Index of entry. + * + * This function is the equivalent of calling xa_store() with %NULL as + * the third argument. The XArray does not need to allocate memory, so + * the user does not need to provide GFP flags. + * + * Context: Process context. Takes and releases the xa_lock. + * Return: The entry which used to be at this index. + */ +static inline void *xa_erase(struct xarray *xa, unsigned long index) +{ + return xa_store(xa, index, NULL, 0); +} + #define xa_trylock(xa) spin_trylock(&(xa)->xa_lock) #define xa_lock(xa) spin_lock(&(xa)->xa_lock) #define xa_unlock(xa) spin_unlock(&(xa)->xa_lock) @@ -322,11 +347,65 @@ static inline bool xa_marked(const struct xarray *xa, xa_mark_t mark) spin_unlock_irqrestore(&(xa)->xa_lock, flags) /* - * Versions of the normal API which require the caller to hold the xa_lock. - */ + * Versions of the normal API which require the caller to hold the + * xa_lock. If the GFP flags allow it, they will drop the lock to + * allocate memory, then reacquire it afterwards. These functions + * may also re-enable interrupts if the XArray flags indicate the + * locking should be interrupt safe. + */ +void *__xa_erase(struct xarray *, unsigned long index); +void *__xa_store(struct xarray *, unsigned long index, void *entry, gfp_t); void __xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); void __xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); +/** + * xa_erase_bh() - Erase this entry from the XArray. + * @xa: XArray. + * @index: Index of entry. + * + * This function is the equivalent of calling xa_store() with %NULL as + * the third argument. The XArray does not need to allocate memory, so + * the user does not need to provide GFP flags. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling softirqs. + * Return: The entry which used to be at this index. + */ +static inline void *xa_erase_bh(struct xarray *xa, unsigned long index) +{ + void *entry; + + xa_lock_bh(xa); + entry = __xa_erase(xa, index); + xa_unlock_bh(xa); + + return entry; +} + +/** + * xa_erase_irq() - Erase this entry from the XArray. + * @xa: XArray. + * @index: Index of entry. + * + * This function is the equivalent of calling xa_store() with %NULL as + * the third argument. The XArray does not need to allocate memory, so + * the user does not need to provide GFP flags. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling interrupts. + * Return: The entry which used to be at this index. + */ +static inline void *xa_erase_irq(struct xarray *xa, unsigned long index) +{ + void *entry; + + xa_lock_irq(xa); + entry = __xa_erase(xa, index); + xa_unlock_irq(xa); + + return entry; +} + /* Everything below here is the Advanced API. Proceed with caution. */ /* @@ -442,6 +521,12 @@ static inline struct xa_node *xa_parent_locked(const struct xarray *xa, } /* Private */ +static inline void *xa_mk_node(const struct xa_node *node) +{ + return (void *)((unsigned long)node | 2); +} + +/* Private */ static inline struct xa_node *xa_to_node(const void *entry) { return (struct xa_node *)((unsigned long)entry - 2); @@ -647,6 +732,12 @@ static inline bool xas_not_node(struct xa_node *node) return ((unsigned long)node & 3) || !node; } +/* True if the node represents head-of-tree, RESTART or BOUNDS */ +static inline bool xas_top(struct xa_node *node) +{ + return node <= XAS_RESTART; +} + /** * xas_reset() - Reset an XArray operation state. * @xas: XArray operation state. @@ -683,10 +774,14 @@ static inline bool xas_retry(struct xa_state *xas, const void *entry) } void *xas_load(struct xa_state *); +void *xas_store(struct xa_state *, void *entry); bool xas_get_mark(const struct xa_state *, xa_mark_t); void xas_set_mark(const struct xa_state *, xa_mark_t); void xas_clear_mark(const struct xa_state *, xa_mark_t); +void xas_init_marks(const struct xa_state *); + +bool xas_nomem(struct xa_state *, gfp_t); /** * xas_reload() - Refetch an entry from the xarray. @@ -711,4 +806,52 @@ static inline void *xas_reload(struct xa_state *xas) return xa_head(xas->xa); } +/** + * xas_set() - Set up XArray operation state for a different index. + * @xas: XArray operation state. + * @index: New index into the XArray. + * + * Move the operation state to refer to a different index. This will + * have the effect of starting a walk from the top; see xas_next() + * to move to an adjacent index. + */ +static inline void xas_set(struct xa_state *xas, unsigned long index) +{ + xas->xa_index = index; + xas->xa_node = XAS_RESTART; +} + +/** + * xas_set_order() - Set up XArray operation state for a multislot entry. + * @xas: XArray operation state. + * @index: Target of the operation. + * @order: Entry occupies 2^@order indices. + */ +static inline void xas_set_order(struct xa_state *xas, unsigned long index, + unsigned int order) +{ +#ifdef CONFIG_XARRAY_MULTI + xas->xa_index = order < BITS_PER_LONG ? (index >> order) << order : 0; + xas->xa_shift = order - (order % XA_CHUNK_SHIFT); + xas->xa_sibs = (1 << (order % XA_CHUNK_SHIFT)) - 1; + xas->xa_node = XAS_RESTART; +#else + BUG_ON(order > 0); + xas_set(xas, index); +#endif +} + +/** + * xas_set_update() - Set up XArray operation state for a callback. + * @xas: XArray operation state. + * @update: Function to call when updating a node. + * + * The XArray can notify a caller after it has updated an xa_node. + * This is advanced functionality and is only needed by the page cache. + */ +static inline void xas_set_update(struct xa_state *xas, xa_update_node_t update) +{ + xas->xa_update = update; +} + #endif /* _LINUX_XARRAY_H */ diff --git a/lib/radix-tree.c b/lib/radix-tree.c index b8e961428484..3479d93c32b9 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -47,7 +47,7 @@ static unsigned long height_to_maxnodes[RADIX_TREE_MAX_PATH + 1] __read_mostly; /* * Radix tree node cache. */ -static struct kmem_cache *radix_tree_node_cachep; +struct kmem_cache *radix_tree_node_cachep; /* * The radix tree is variable-height, so an insert operation not only has @@ -365,7 +365,7 @@ out: return ret; } -static void radix_tree_node_rcu_free(struct rcu_head *head) +void radix_tree_node_rcu_free(struct rcu_head *head) { struct radix_tree_node *node = container_of(head, struct radix_tree_node, rcu_head); diff --git a/lib/test_xarray.c b/lib/test_xarray.c index f8b0e9ba80a4..b711030fbc32 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -30,13 +30,49 @@ void xa_dump(const struct xarray *xa) { } static void *xa_store_index(struct xarray *xa, unsigned long index, gfp_t gfp) { - radix_tree_insert(xa, index, xa_mk_value(index)); - return NULL; + return xa_store(xa, index, xa_mk_value(index & LONG_MAX), gfp); } static void xa_erase_index(struct xarray *xa, unsigned long index) { - radix_tree_delete(xa, index); + XA_BUG_ON(xa, xa_erase(xa, index) != xa_mk_value(index & LONG_MAX)); + XA_BUG_ON(xa, xa_load(xa, index) != NULL); +} + +/* + * If anyone needs this, please move it to xarray.c. We have no current + * users outside the test suite because all current multislot users want + * to use the advanced API. + */ +static void *xa_store_order(struct xarray *xa, unsigned long index, + unsigned order, void *entry, gfp_t gfp) +{ + XA_STATE_ORDER(xas, xa, index, order); + void *curr; + + do { + xas_lock(&xas); + curr = xas_store(&xas, entry); + xas_unlock(&xas); + } while (xas_nomem(&xas, gfp)); + + return curr; +} + +static noinline void check_xa_err(struct xarray *xa) +{ + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 0, GFP_NOWAIT)) != 0); + XA_BUG_ON(xa, xa_err(xa_erase(xa, 0)) != 0); +#ifndef __KERNEL__ + /* The kernel does not fail GFP_NOWAIT allocations */ + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_NOWAIT)) != -ENOMEM); + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_NOWAIT)) != -ENOMEM); +#endif + XA_BUG_ON(xa, xa_err(xa_store_index(xa, 1, GFP_KERNEL)) != 0); + XA_BUG_ON(xa, xa_err(xa_store(xa, 1, xa_mk_value(0), GFP_KERNEL)) != 0); + XA_BUG_ON(xa, xa_err(xa_erase(xa, 1)) != 0); +// kills the test-suite :-( +// XA_BUG_ON(xa, xa_err(xa_store(xa, 0, xa_mk_internal(0), 0)) != -EINVAL); } static noinline void check_xa_load(struct xarray *xa) @@ -69,6 +105,9 @@ static noinline void check_xa_load(struct xarray *xa) static noinline void check_xa_mark_1(struct xarray *xa, unsigned long index) { + unsigned int order; + unsigned int max_order = IS_ENABLED(CONFIG_XARRAY_MULTI) ? 8 : 1; + /* NULL elements have no marks set */ XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); xa_set_mark(xa, index, XA_MARK_0); @@ -90,6 +129,37 @@ static noinline void check_xa_mark_1(struct xarray *xa, unsigned long index) XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); xa_set_mark(xa, index, XA_MARK_0); XA_BUG_ON(xa, xa_get_mark(xa, index, XA_MARK_0)); + + /* + * Storing a multi-index entry over entries with marks gives the + * entire entry the union of the marks + */ + BUG_ON((index % 4) != 0); + for (order = 2; order < max_order; order++) { + unsigned long base = round_down(index, 1UL << order); + unsigned long next = base + (1UL << order); + unsigned long i; + + XA_BUG_ON(xa, xa_store_index(xa, index + 1, GFP_KERNEL)); + xa_set_mark(xa, index + 1, XA_MARK_0); + XA_BUG_ON(xa, xa_store_index(xa, index + 2, GFP_KERNEL)); + xa_set_mark(xa, index + 2, XA_MARK_1); + XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL)); + xa_store_order(xa, index, order, xa_mk_value(index), + GFP_KERNEL); + for (i = base; i < next; i++) { + XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_0)); + XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_1)); + XA_BUG_ON(xa, xa_get_mark(xa, i, XA_MARK_2)); + } + XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_0)); + XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_1)); + XA_BUG_ON(xa, xa_get_mark(xa, next, XA_MARK_2)); + xa_erase_index(xa, index); + xa_erase_index(xa, next); + XA_BUG_ON(xa, !xa_empty(xa)); + } + XA_BUG_ON(xa, !xa_empty(xa)); } static noinline void check_xa_mark(struct xarray *xa) @@ -100,12 +170,111 @@ static noinline void check_xa_mark(struct xarray *xa) check_xa_mark_1(xa, index); } -static RADIX_TREE(array, GFP_KERNEL); +static noinline void check_xa_shrink(struct xarray *xa) +{ + XA_STATE(xas, xa, 1); + struct xa_node *node; + + XA_BUG_ON(xa, !xa_empty(xa)); + XA_BUG_ON(xa, xa_store_index(xa, 0, GFP_KERNEL) != NULL); + XA_BUG_ON(xa, xa_store_index(xa, 1, GFP_KERNEL) != NULL); + + /* + * Check that erasing the entry at 1 shrinks the tree and properly + * marks the node as being deleted. + */ + xas_lock(&xas); + XA_BUG_ON(xa, xas_load(&xas) != xa_mk_value(1)); + node = xas.xa_node; + XA_BUG_ON(xa, xa_entry_locked(xa, node, 0) != xa_mk_value(0)); + XA_BUG_ON(xa, xas_store(&xas, NULL) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 1) != NULL); + XA_BUG_ON(xa, xas.xa_node != XAS_BOUNDS); + XA_BUG_ON(xa, xa_entry_locked(xa, node, 0) != XA_RETRY_ENTRY); + XA_BUG_ON(xa, xas_load(&xas) != NULL); + xas_unlock(&xas); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0)); + xa_erase_index(xa, 0); + XA_BUG_ON(xa, !xa_empty(xa)); +} + +static noinline void check_multi_store(struct xarray *xa) +{ +#ifdef CONFIG_XARRAY_MULTI + unsigned long i, j, k; + unsigned int max_order = (sizeof(long) == 4) ? 30 : 60; + + /* Loading from any position returns the same value */ + xa_store_order(xa, 0, 1, xa_mk_value(0), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 2) != NULL); + rcu_read_lock(); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 2); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2); + rcu_read_unlock(); + + /* Storing adjacent to the value does not alter the value */ + xa_store(xa, 3, xa, GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(0)); + XA_BUG_ON(xa, xa_load(xa, 2) != NULL); + rcu_read_lock(); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 3); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2); + rcu_read_unlock(); + + /* Overwriting multiple indexes works */ + xa_store_order(xa, 0, 2, xa_mk_value(1), GFP_KERNEL); + XA_BUG_ON(xa, xa_load(xa, 0) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 2) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 3) != xa_mk_value(1)); + XA_BUG_ON(xa, xa_load(xa, 4) != NULL); + rcu_read_lock(); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 4); + XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 4); + rcu_read_unlock(); + + /* We can erase multiple values with a single store */ + xa_store_order(xa, 0, 63, NULL, GFP_KERNEL); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Even when the first slot is empty but the others aren't */ + xa_store_index(xa, 1, GFP_KERNEL); + xa_store_index(xa, 2, GFP_KERNEL); + xa_store_order(xa, 0, 2, NULL, GFP_KERNEL); + XA_BUG_ON(xa, !xa_empty(xa)); + + for (i = 0; i < max_order; i++) { + for (j = 0; j < max_order; j++) { + xa_store_order(xa, 0, i, xa_mk_value(i), GFP_KERNEL); + xa_store_order(xa, 0, j, xa_mk_value(j), GFP_KERNEL); + + for (k = 0; k < max_order; k++) { + void *entry = xa_load(xa, (1UL << k) - 1); + if ((i < k) && (j < k)) + XA_BUG_ON(xa, entry != NULL); + else + XA_BUG_ON(xa, entry != xa_mk_value(j)); + } + + xa_erase(xa, 0); + XA_BUG_ON(xa, !xa_empty(xa)); + } + } +#endif +} + +static DEFINE_XARRAY(array); static int xarray_checks(void) { + check_xa_err(&array); check_xa_load(&array); check_xa_mark(&array); + check_xa_shrink(&array); + check_multi_store(&array); printk("XArray: %u of %u tests passed\n", tests_passed, tests_run); return (tests_run == tests_passed) ? 0 : -EINVAL; diff --git a/lib/xarray.c b/lib/xarray.c index aa86c47e532f..4596a95ed9cd 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -7,6 +7,8 @@ #include <linux/bitmap.h> #include <linux/export.h> +#include <linux/list.h> +#include <linux/slab.h> #include <linux/xarray.h> /* @@ -25,6 +27,31 @@ * @entry refers to something stored in a slot in the xarray */ +static inline unsigned int xa_lock_type(const struct xarray *xa) +{ + return (__force unsigned int)xa->xa_flags & 3; +} + +static inline void xas_lock_type(struct xa_state *xas, unsigned int lock_type) +{ + if (lock_type == XA_LOCK_IRQ) + xas_lock_irq(xas); + else if (lock_type == XA_LOCK_BH) + xas_lock_bh(xas); + else + xas_lock(xas); +} + +static inline void xas_unlock_type(struct xa_state *xas, unsigned int lock_type) +{ + if (lock_type == XA_LOCK_IRQ) + xas_unlock_irq(xas); + else if (lock_type == XA_LOCK_BH) + xas_unlock_bh(xas); + else + xas_unlock(xas); +} + static inline void xa_mark_set(struct xarray *xa, xa_mark_t mark) { if (!(xa->xa_flags & XA_FLAGS_MARK(mark))) @@ -67,6 +94,34 @@ static inline bool node_any_mark(struct xa_node *node, xa_mark_t mark) return !bitmap_empty(node_marks(node, mark), XA_CHUNK_SIZE); } +#define mark_inc(mark) do { \ + mark = (__force xa_mark_t)((__force unsigned)(mark) + 1); \ +} while (0) + +/* + * xas_squash_marks() - Merge all marks to the first entry + * @xas: Array operation state. + * + * Set a mark on the first entry if any entry has it set. Clear marks on + * all sibling entries. + */ +static void xas_squash_marks(const struct xa_state *xas) +{ + unsigned int mark = 0; + unsigned int limit = xas->xa_offset + xas->xa_sibs + 1; + + if (!xas->xa_sibs) + return; + + do { + unsigned long *marks = xas->xa_node->marks[mark]; + if (find_next_bit(marks, limit, xas->xa_offset + 1) == limit) + continue; + __set_bit(xas->xa_offset, marks); + bitmap_clear(marks, xas->xa_offset + 1, xas->xa_sibs); + } while (mark++ != (__force unsigned)XA_MARK_MAX); +} + /* extracts the offset within this node from the index */ static unsigned int get_offset(unsigned long index, struct xa_node *node) { @@ -161,6 +216,516 @@ void *xas_load(struct xa_state *xas) } EXPORT_SYMBOL_GPL(xas_load); +/* Move the radix tree node cache here */ +extern struct kmem_cache *radix_tree_node_cachep; +extern void radix_tree_node_rcu_free(struct rcu_head *head); + +#define XA_RCU_FREE ((struct xarray *)1) + +static void xa_node_free(struct xa_node *node) +{ + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); + node->array = XA_RCU_FREE; + call_rcu(&node->rcu_head, radix_tree_node_rcu_free); +} + +/* + * xas_destroy() - Free any resources allocated during the XArray operation. + * @xas: XArray operation state. + * + * This function is now internal-only. + */ +static void xas_destroy(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_alloc; + + if (!node) + return; + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); + kmem_cache_free(radix_tree_node_cachep, node); + xas->xa_alloc = NULL; +} + +/** + * xas_nomem() - Allocate memory if needed. + * @xas: XArray operation state. + * @gfp: Memory allocation flags. + * + * If we need to add new nodes to the XArray, we try to allocate memory + * with GFP_NOWAIT while holding the lock, which will usually succeed. + * If it fails, @xas is flagged as needing memory to continue. The caller + * should drop the lock and call xas_nomem(). If xas_nomem() succeeds, + * the caller should retry the operation. + * + * Forward progress is guaranteed as one node is allocated here and + * stored in the xa_state where it will be found by xas_alloc(). More + * nodes will likely be found in the slab allocator, but we do not tie + * them up here. + * + * Return: true if memory was needed, and was successfully allocated. + */ +bool xas_nomem(struct xa_state *xas, gfp_t gfp) +{ + if (xas->xa_node != XA_ERROR(-ENOMEM)) { + xas_destroy(xas); + return false; + } + xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); + if (!xas->xa_alloc) + return false; + XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list)); + xas->xa_node = XAS_RESTART; + return true; +} +EXPORT_SYMBOL_GPL(xas_nomem); + +/* + * __xas_nomem() - Drop locks and allocate memory if needed. + * @xas: XArray operation state. + * @gfp: Memory allocation flags. + * + * Internal variant of xas_nomem(). + * + * Return: true if memory was needed, and was successfully allocated. + */ +static bool __xas_nomem(struct xa_state *xas, gfp_t gfp) + __must_hold(xas->xa->xa_lock) +{ + unsigned int lock_type = xa_lock_type(xas->xa); + + if (xas->xa_node != XA_ERROR(-ENOMEM)) { + xas_destroy(xas); + return false; + } + if (gfpflags_allow_blocking(gfp)) { + xas_unlock_type(xas, lock_type); + xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); + xas_lock_type(xas, lock_type); + } else { + xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); + } + if (!xas->xa_alloc) + return false; + XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list)); + xas->xa_node = XAS_RESTART; + return true; +} + +static void xas_update(struct xa_state *xas, struct xa_node *node) +{ + if (xas->xa_update) + xas->xa_update(node); + else + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); +} + +static void *xas_alloc(struct xa_state *xas, unsigned int shift) +{ + struct xa_node *parent = xas->xa_node; + struct xa_node *node = xas->xa_alloc; + + if (xas_invalid(xas)) + return NULL; + + if (node) { + xas->xa_alloc = NULL; + } else { + node = kmem_cache_alloc(radix_tree_node_cachep, + GFP_NOWAIT | __GFP_NOWARN); + if (!node) { + xas_set_err(xas, -ENOMEM); + return NULL; + } + } + + if (parent) { + node->offset = xas->xa_offset; + parent->count++; + XA_NODE_BUG_ON(node, parent->count > XA_CHUNK_SIZE); + xas_update(xas, parent); + } + XA_NODE_BUG_ON(node, shift > BITS_PER_LONG); + XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); + node->shift = shift; + node->count = 0; + node->nr_values = 0; + RCU_INIT_POINTER(node->parent, xas->xa_node); + node->array = xas->xa; + + return node; +} + +/* + * Use this to calculate the maximum index that will need to be created + * in order to add the entry described by @xas. Because we cannot store a + * multiple-index entry at index 0, the calculation is a little more complex + * than you might expect. + */ +static unsigned long xas_max(struct xa_state *xas) +{ + unsigned long max = xas->xa_index; + +#ifdef CONFIG_XARRAY_MULTI + if (xas->xa_shift || xas->xa_sibs) { + unsigned long mask; + mask = (((xas->xa_sibs + 1UL) << xas->xa_shift) - 1); + max |= mask; + if (mask == max) + max++; + } +#endif + + return max; +} + +/* The maximum index that can be contained in the array without expanding it */ +static unsigned long max_index(void *entry) +{ + if (!xa_is_node(entry)) + return 0; + return (XA_CHUNK_SIZE << xa_to_node(entry)->shift) - 1; +} + +static void xas_shrink(struct xa_state *xas) +{ + struct xarray *xa = xas->xa; + struct xa_node *node = xas->xa_node; + + for (;;) { + void *entry; + + XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); + if (node->count != 1) + break; + entry = xa_entry_locked(xa, node, 0); + if (!entry) + break; + if (!xa_is_node(entry) && node->shift) + break; + xas->xa_node = XAS_BOUNDS; + + RCU_INIT_POINTER(xa->xa_head, entry); + + node->count = 0; + node->nr_values = 0; + if (!xa_is_node(entry)) + RCU_INIT_POINTER(node->slots[0], XA_RETRY_ENTRY); + xas_update(xas, node); + xa_node_free(node); + if (!xa_is_node(entry)) + break; + node = xa_to_node(entry); + node->parent = NULL; + } +} + +/* + * xas_delete_node() - Attempt to delete an xa_node + * @xas: Array operation state. + * + * Attempts to delete the @xas->xa_node. This will fail if xa->node has + * a non-zero reference count. + */ +static void xas_delete_node(struct xa_state *xas) +{ + struct xa_node *node = xas->xa_node; + + for (;;) { + struct xa_node *parent; + + XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); + if (node->count) + break; + + parent = xa_parent_locked(xas->xa, node); + xas->xa_node = parent; + xas->xa_offset = node->offset; + xa_node_free(node); + + if (!parent) { + xas->xa->xa_head = NULL; + xas->xa_node = XAS_BOUNDS; + return; + } + + parent->slots[xas->xa_offset] = NULL; + parent->count--; + XA_NODE_BUG_ON(parent, parent->count > XA_CHUNK_SIZE); + node = parent; + xas_update(xas, node); + } + + if (!node->parent) + xas_shrink(xas); +} + +/** + * xas_free_nodes() - Free this node and all nodes that it references + * @xas: Array operation state. + * @top: Node to free + * + * This node has been removed from the tree. We must now free it and all + * of its subnodes. There may be RCU walkers with references into the tree, + * so we must replace all entries with retry markers. + */ +static void xas_free_nodes(struct xa_state *xas, struct xa_node *top) +{ + unsigned int offset = 0; + struct xa_node *node = top; + + for (;;) { + void *entry = xa_entry_locked(xas->xa, node, offset); + + if (xa_is_node(entry)) { + node = xa_to_node(entry); + offset = 0; + continue; + } + if (entry) + RCU_INIT_POINTER(node->slots[offset], XA_RETRY_ENTRY); + offset++; + while (offset == XA_CHUNK_SIZE) { + struct xa_node *parent; + + parent = xa_parent_locked(xas->xa, node); + offset = node->offset + 1; + node->count = 0; + node->nr_values = 0; + xas_update(xas, node); + xa_node_free(node); + if (node == top) + return; + node = parent; + } + } +} + +/* + * xas_expand adds nodes to the head of the tree until it has reached + * sufficient height to be able to contain @xas->xa_index + */ +static int xas_expand(struct xa_state *xas, void *head) +{ + struct xarray *xa = xas->xa; + struct xa_node *node = NULL; + unsigned int shift = 0; + unsigned long max = xas_max(xas); + + if (!head) { + if (max == 0) + return 0; + while ((max >> shift) >= XA_CHUNK_SIZE) + shift += XA_CHUNK_SHIFT; + return shift + XA_CHUNK_SHIFT; + } else if (xa_is_node(head)) { + node = xa_to_node(head); + shift = node->shift + XA_CHUNK_SHIFT; + } + xas->xa_node = NULL; + + while (max > max_index(head)) { + xa_mark_t mark = 0; + + XA_NODE_BUG_ON(node, shift > BITS_PER_LONG); + node = xas_alloc(xas, shift); + if (!node) + return -ENOMEM; + + node->count = 1; + if (xa_is_value(head)) + node->nr_values = 1; + RCU_INIT_POINTER(node->slots[0], head); + + /* Propagate the aggregated mark info to the new child */ + for (;;) { + if (xa_marked(xa, mark)) + node_set_mark(node, 0, mark); + if (mark == XA_MARK_MAX) + break; + mark_inc(mark); + } + + /* + * Now that the new node is fully initialised, we can add + * it to the tree + */ + if (xa_is_node(head)) { + xa_to_node(head)->offset = 0; + rcu_assign_pointer(xa_to_node(head)->parent, node); + } + head = xa_mk_node(node); + rcu_assign_pointer(xa->xa_head, head); + xas_update(xas, node); + + shift += XA_CHUNK_SHIFT; + } + + xas->xa_node = node; + return shift; +} + +/* + * xas_create() - Create a slot to store an entry in. + * @xas: XArray operation state. + * + * Most users will not need to call this function directly, as it is called + * by xas_store(). It is useful for doing conditional store operations + * (see the xa_cmpxchg() implementation for an example). + * + * Return: If the slot already existed, returns the contents of this slot. + * If the slot was newly created, returns NULL. If it failed to create the + * slot, returns NULL and indicates the error in @xas. + */ +static void *xas_create(struct xa_state *xas) +{ + struct xarray *xa = xas->xa; + void *entry; + void __rcu **slot; + struct xa_node *node = xas->xa_node; + int shift; + unsigned int order = xas->xa_shift; + + if (xas_top(node)) { + entry = xa_head_locked(xa); + xas->xa_node = NULL; + shift = xas_expand(xas, entry); + if (shift < 0) + return NULL; + entry = xa_head_locked(xa); + slot = &xa->xa_head; + } else if (xas_error(xas)) { + return NULL; + } else if (node) { + unsigned int offset = xas->xa_offset; + + shift = node->shift; + entry = xa_entry_locked(xa, node, offset); + slot = &node->slots[offset]; + } else { + shift = 0; + entry = xa_head_locked(xa); + slot = &xa->xa_head; + } + + while (shift > order) { + shift -= XA_CHUNK_SHIFT; + if (!entry) { + node = xas_alloc(xas, shift); + if (!node) + break; + rcu_assign_pointer(*slot, xa_mk_node(node)); + } else if (xa_is_node(entry)) { + node = xa_to_node(entry); + } else { + break; + } + entry = xas_descend(xas, node); + slot = &node->slots[xas->xa_offset]; + } + + return entry; +} + +static void update_node(struct xa_state *xas, struct xa_node *node, + int count, int values) +{ + if (!node || (!count && !values)) + return; + + node->count += count; + node->nr_values += values; + XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); + XA_NODE_BUG_ON(node, node->nr_values > XA_CHUNK_SIZE); + xas_update(xas, node); + if (count < 0) + xas_delete_node(xas); +} + +/** + * xas_store() - Store this entry in the XArray. + * @xas: XArray operation state. + * @entry: New entry. + * + * If @xas is operating on a multi-index entry, the entry returned by this + * function is essentially meaningless (it may be an internal entry or it + * may be %NULL, even if there are non-NULL entries at some of the indices + * covered by the range). This is not a problem for any current users, + * and can be changed if needed. + * + * Return: The old entry at this index. + */ +void *xas_store(struct xa_state *xas, void *entry) +{ + struct xa_node *node; + void __rcu **slot = &xas->xa->xa_head; + unsigned int offset, max; + int count = 0; + int values = 0; + void *first, *next; + bool value = xa_is_value(entry); + + if (entry) + first = xas_create(xas); + else + first = xas_load(xas); + + if (xas_invalid(xas)) + return first; + node = xas->xa_node; + if (node && (xas->xa_shift < node->shift)) + xas->xa_sibs = 0; + if ((first == entry) && !xas->xa_sibs) + return first; + + next = first; + offset = xas->xa_offset; + max = xas->xa_offset + xas->xa_sibs; + if (node) { + slot = &node->slots[offset]; + if (xas->xa_sibs) + xas_squash_marks(xas); + } + if (!entry) + xas_init_marks(xas); + + for (;;) { + /* + * Must clear the marks before setting the entry to NULL, + * otherwise xas_for_each_marked may find a NULL entry and + * stop early. rcu_assign_pointer contains a release barrier + * so the mark clearing will appear to happen before the + * entry is set to NULL. + */ + rcu_assign_pointer(*slot, entry); + if (xa_is_node(next)) + xas_free_nodes(xas, xa_to_node(next)); + if (!node) + break; + count += !next - !entry; + values += !xa_is_value(first) - !value; + if (entry) { + if (offset == max) + break; + if (!xa_is_sibling(entry)) + entry = xa_mk_sibling(xas->xa_offset); + } else { + if (offset == XA_CHUNK_MASK) + break; + } + next = xa_entry_locked(xas->xa, node, ++offset); + if (!xa_is_sibling(next)) { + if (!entry && (offset > max)) + break; + first = next; + } + slot++; + } + + update_node(xas, node, count, values); + return first; +} +EXPORT_SYMBOL_GPL(xas_store); + /** * xas_get_mark() - Returns the state of this mark. * @xas: XArray operation state. @@ -241,6 +806,30 @@ void xas_clear_mark(const struct xa_state *xas, xa_mark_t mark) EXPORT_SYMBOL_GPL(xas_clear_mark); /** + * xas_init_marks() - Initialise all marks for the entry + * @xas: Array operations state. + * + * Initialise all marks for the entry specified by @xas. If we're tracking + * free entries with a mark, we need to set it on all entries. All other + * marks are cleared. + * + * This implementation is not as efficient as it could be; we may walk + * up the tree multiple times. + */ +void xas_init_marks(const struct xa_state *xas) +{ + xa_mark_t mark = 0; + + for (;;) { + xas_clear_mark(xas, mark); + if (mark == XA_MARK_MAX) + break; + mark_inc(mark); + } +} +EXPORT_SYMBOL_GPL(xas_init_marks); + +/** * xa_init_flags() - Initialise an empty XArray with flags. * @xa: XArray. * @flags: XA_FLAG values. @@ -253,9 +842,19 @@ EXPORT_SYMBOL_GPL(xas_clear_mark); */ void xa_init_flags(struct xarray *xa, gfp_t flags) { + unsigned int lock_type; + static struct lock_class_key xa_lock_irq; + static struct lock_class_key xa_lock_bh; + spin_lock_init(&xa->xa_lock); xa->xa_flags = flags; xa->xa_head = NULL; + + lock_type = xa_lock_type(xa); + if (lock_type == XA_LOCK_IRQ) + lockdep_set_class(&xa->xa_lock, &xa_lock_irq); + else if (lock_type == XA_LOCK_BH) + lockdep_set_class(&xa->xa_lock, &xa_lock_bh); } EXPORT_SYMBOL(xa_init_flags); @@ -282,6 +881,100 @@ void *xa_load(struct xarray *xa, unsigned long index) } EXPORT_SYMBOL(xa_load); +static void *xas_result(struct xa_state *xas, void *curr) +{ + XA_NODE_BUG_ON(xas->xa_node, xa_is_internal(curr)); + if (xas_error(xas)) + curr = xas->xa_node; + return curr; +} + +/** + * __xa_erase() - Erase this entry from the XArray while locked. + * @xa: XArray. + * @index: Index into array. + * + * If the entry at this index is a multi-index entry then all indices will + * be erased, and the entry will no longer be a multi-index entry. + * This function expects the xa_lock to be held on entry. + * + * Context: Any context. Expects xa_lock to be held on entry. May + * release and reacquire xa_lock if @gfp flags permit. + * Return: The old entry at this index. + */ +void *__xa_erase(struct xarray *xa, unsigned long index) +{ + XA_STATE(xas, xa, index); + return xas_result(&xas, xas_store(&xas, NULL)); +} +EXPORT_SYMBOL_GPL(__xa_erase); + +/** + * xa_store() - Store this entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * After this function returns, loads from this index will return @entry. + * Storing into an existing multislot entry updates the entry of every index. + * The marks associated with @index are unaffected unless @entry is %NULL. + * + * Context: Process context. Takes and releases the xa_lock. May sleep + * if the @gfp flags permit. + * Return: The old entry at this index on success, xa_err(-EINVAL) if @entry + * cannot be stored in an XArray, or xa_err(-ENOMEM) if memory allocation + * failed. + */ +void *xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, index); + void *curr; + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return XA_ERROR(-EINVAL); + + do { + xas_lock(&xas); + curr = xas_store(&xas, entry); + xas_unlock(&xas); + } while (xas_nomem(&xas, gfp)); + + return xas_result(&xas, curr); +} +EXPORT_SYMBOL(xa_store); + +/** + * __xa_store() - Store this entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * You must already be holding the xa_lock when calling this function. + * It will drop the lock if needed to allocate memory, and then reacquire + * it afterwards. + * + * Context: Any context. Expects xa_lock to be held on entry. May + * release and reacquire xa_lock if @gfp flags permit. + * Return: The old entry at this index or xa_err() if an error happened. + */ +void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) +{ + XA_STATE(xas, xa, index); + void *curr; + + if (WARN_ON_ONCE(xa_is_internal(entry))) + return XA_ERROR(-EINVAL); + + do { + curr = xas_store(&xas, entry); + } while (__xas_nomem(&xas, gfp)); + + return xas_result(&xas, curr); +} +EXPORT_SYMBOL(__xa_store); + /** * __xa_set_mark() - Set this mark on this entry while locked. * @xa: XArray. diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h index e63662db131b..05dca5c203f3 100644 --- a/tools/include/linux/bitmap.h +++ b/tools/include/linux/bitmap.h @@ -15,6 +15,7 @@ void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, int bits); int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits); +void bitmap_clear(unsigned long *map, unsigned int start, int len); #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) diff --git a/tools/include/linux/spinlock.h b/tools/include/linux/spinlock.h index 622266b197d0..c934572d935c 100644 --- a/tools/include/linux/spinlock.h +++ b/tools/include/linux/spinlock.h @@ -37,4 +37,6 @@ static inline bool arch_spin_is_locked(arch_spinlock_t *mutex) return true; } +#include <linux/lockdep.h> + #endif diff --git a/tools/testing/radix-tree/Makefile b/tools/testing/radix-tree/Makefile index 1379f1d78d0b..acf1afa01c5b 100644 --- a/tools/testing/radix-tree/Makefile +++ b/tools/testing/radix-tree/Makefile @@ -5,7 +5,7 @@ CFLAGS += -I. -I../../include -g -Og -Wall -D_LGPL_SOURCE -fsanitize=address \ LDFLAGS += -fsanitize=address -fsanitize=undefined LDLIBS+= -lpthread -lurcu TARGETS = main idr-test multiorder xarray -CORE_OFILES := xarray.o radix-tree.o idr.o linux.o test.o find_bit.o +CORE_OFILES := xarray.o radix-tree.o idr.o linux.o test.o find_bit.o bitmap.o OFILES = main.o $(CORE_OFILES) regression1.o regression2.o regression3.o \ tag_check.o multiorder.o idr-test.o iteration_check.o benchmark.o diff --git a/tools/testing/radix-tree/bitmap.c b/tools/testing/radix-tree/bitmap.c new file mode 100644 index 000000000000..66ec4a24a203 --- /dev/null +++ b/tools/testing/radix-tree/bitmap.c @@ -0,0 +1,23 @@ +/* lib/bitmap.c pulls in at least two other files. */ + +#include <linux/bitmap.h> + +void bitmap_clear(unsigned long *map, unsigned int start, int len) +{ + unsigned long *p = map + BIT_WORD(start); + const unsigned int size = start + len; + int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + + while (len - bits_to_clear >= 0) { + *p &= ~mask_to_clear; + len -= bits_to_clear; + bits_to_clear = BITS_PER_LONG; + mask_to_clear = ~0UL; + p++; + } + if (len) { + mask_to_clear &= BITMAP_LAST_WORD_MASK(size); + *p &= ~mask_to_clear; + } +} diff --git a/tools/testing/radix-tree/linux/kernel.h b/tools/testing/radix-tree/linux/kernel.h index 5d06ac75a14d..4568248222ae 100644 --- a/tools/testing/radix-tree/linux/kernel.h +++ b/tools/testing/radix-tree/linux/kernel.h @@ -18,4 +18,8 @@ #define pr_debug printk #define pr_cont printk +#define __acquires(x) +#define __releases(x) +#define __must_hold(x) + #endif /* _KERNEL_H */ diff --git a/tools/testing/radix-tree/linux/lockdep.h b/tools/testing/radix-tree/linux/lockdep.h new file mode 100644 index 000000000000..565fccdfe6e9 --- /dev/null +++ b/tools/testing/radix-tree/linux/lockdep.h @@ -0,0 +1,11 @@ +#ifndef _LINUX_LOCKDEP_H +#define _LINUX_LOCKDEP_H +struct lock_class_key { + unsigned int a; +}; + +static inline void lockdep_set_class(spinlock_t *lock, + struct lock_class_key *key) +{ +} +#endif /* _LINUX_LOCKDEP_H */ |