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authorLinus Torvalds <torvalds@linux-foundation.org>2019-01-22 17:08:30 +1300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-22 17:08:30 +1300
commit48b161983ae5266ffa42f0ccaf7224eaeda38e59 (patch)
tree1f454173fbb4087759c95f69c841990045dcbc5f
parentf8ff6c732d35904d773043f979b844ef330c701b (diff)
parentedcddd4c879af48ec922d680b2d56834c085683b (diff)
download96b-common-48b161983ae5266ffa42f0ccaf7224eaeda38e59.tar.gz
Merge tag 'xarray-5.0-rc3' of git://git.infradead.org/users/willy/linux-dax
Pull XArray fixes from Matthew Wilcox: "Fix some oversights in the XArray porcelain API: - support for m68k's two-byte aligned pointers - reserving entries using xa_insert() - missing xa_insert_bh() and xa_insert_irq() functions - simplify using xa_for_each() - use lockdep correctly - a few other minor fixes and improvements" * tag 'xarray-5.0-rc3' of git://git.infradead.org/users/willy/linux-dax: XArray: Fix an arithmetic error in xa_is_err XArray tests: Check mark 2 gets squashed XArray: Fix typo in comment XArray: Honour reserved entries in xa_insert XArray: Permit storing 2-byte-aligned pointers XArray: Change xa_for_each iterator XArray: Turn xa_init_flags into a static inline XArray tests: Add RCU locking
-rw-r--r--Documentation/core-api/xarray.rst15
-rw-r--r--include/linux/xarray.h227
-rw-r--r--lib/test_xarray.c57
-rw-r--r--lib/xarray.c92
4 files changed, 278 insertions, 113 deletions
diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst
index 6a6d67acaf69..5d54b27c6eba 100644
--- a/Documentation/core-api/xarray.rst
+++ b/Documentation/core-api/xarray.rst
@@ -108,12 +108,13 @@ some, but not all of the other indices changing.
Sometimes you need to ensure that a subsequent call to :c:func:`xa_store`
will not need to allocate memory. The :c:func:`xa_reserve` function
-will store a reserved entry at the indicated index. Users of the normal
-API will see this entry as containing ``NULL``. If you do not need to
-use the reserved entry, you can call :c:func:`xa_release` to remove the
-unused entry. If another user has stored to the entry in the meantime,
-:c:func:`xa_release` will do nothing; if instead you want the entry to
-become ``NULL``, you should use :c:func:`xa_erase`.
+will store a reserved entry at the indicated index. Users of the
+normal API will see this entry as containing ``NULL``. If you do
+not need to use the reserved entry, you can call :c:func:`xa_release`
+to remove the unused entry. If another user has stored to the entry
+in the meantime, :c:func:`xa_release` will do nothing; if instead you
+want the entry to become ``NULL``, you should use :c:func:`xa_erase`.
+Using :c:func:`xa_insert` on a reserved entry will fail.
If all entries in the array are ``NULL``, the :c:func:`xa_empty` function
will return ``true``.
@@ -183,6 +184,8 @@ Takes xa_lock internally:
* :c:func:`xa_store_bh`
* :c:func:`xa_store_irq`
* :c:func:`xa_insert`
+ * :c:func:`xa_insert_bh`
+ * :c:func:`xa_insert_irq`
* :c:func:`xa_erase`
* :c:func:`xa_erase_bh`
* :c:func:`xa_erase_irq`
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index f492e21c4aa2..5d9d318bcf7a 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -176,7 +176,8 @@ static inline bool xa_is_internal(const void *entry)
*/
static inline bool xa_is_err(const void *entry)
{
- return unlikely(xa_is_internal(entry));
+ return unlikely(xa_is_internal(entry) &&
+ entry >= xa_mk_internal(-MAX_ERRNO));
}
/**
@@ -286,7 +287,6 @@ struct xarray {
*/
#define DEFINE_XARRAY_ALLOC(name) DEFINE_XARRAY_FLAGS(name, XA_FLAGS_ALLOC)
-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);
void *xa_erase(struct xarray *, unsigned long index);
@@ -304,6 +304,24 @@ unsigned int xa_extract(struct xarray *, void **dst, unsigned long start,
void xa_destroy(struct xarray *);
/**
+ * xa_init_flags() - Initialise an empty XArray with flags.
+ * @xa: XArray.
+ * @flags: XA_FLAG values.
+ *
+ * If you need to initialise an XArray with special flags (eg you need
+ * to take the lock from interrupt context), use this function instead
+ * of xa_init().
+ *
+ * Context: Any context.
+ */
+static inline void xa_init_flags(struct xarray *xa, gfp_t flags)
+{
+ spin_lock_init(&xa->xa_lock);
+ xa->xa_flags = flags;
+ xa->xa_head = NULL;
+}
+
+/**
* xa_init() - Initialise an empty XArray.
* @xa: XArray.
*
@@ -342,20 +360,45 @@ static inline bool xa_marked(const struct xarray *xa, xa_mark_t mark)
}
/**
- * xa_for_each() - Iterate over a portion of an XArray.
+ * xa_for_each_start() - Iterate over a portion of an XArray.
* @xa: XArray.
+ * @index: Index of @entry.
* @entry: Entry retrieved from array.
+ * @start: First index to retrieve from array.
+ *
+ * During the iteration, @entry will have the value of the entry stored
+ * in @xa at @index. You may modify @index during the iteration if you
+ * want to skip or reprocess indices. It is safe to modify the array
+ * during the iteration. At the end of the iteration, @entry will be set
+ * to NULL and @index will have a value less than or equal to max.
+ *
+ * xa_for_each_start() is O(n.log(n)) while xas_for_each() is O(n). You have
+ * to handle your own locking with xas_for_each(), and if you have to unlock
+ * after each iteration, it will also end up being O(n.log(n)).
+ * xa_for_each_start() will spin if it hits a retry entry; if you intend to
+ * see retry entries, you should use the xas_for_each() iterator instead.
+ * The xas_for_each() iterator will expand into more inline code than
+ * xa_for_each_start().
+ *
+ * Context: Any context. Takes and releases the RCU lock.
+ */
+#define xa_for_each_start(xa, index, entry, start) \
+ for (index = start, \
+ entry = xa_find(xa, &index, ULONG_MAX, XA_PRESENT); \
+ entry; \
+ entry = xa_find_after(xa, &index, ULONG_MAX, XA_PRESENT))
+
+/**
+ * xa_for_each() - Iterate over present entries in an XArray.
+ * @xa: XArray.
* @index: Index of @entry.
- * @max: Maximum index to retrieve from array.
- * @filter: Selection criterion.
+ * @entry: Entry retrieved from array.
*
- * Initialise @index to the lowest index you want to retrieve from the
- * array. During the iteration, @entry will have the value of the entry
- * stored in @xa at @index. The iteration will skip all entries in the
- * array which do not match @filter. You may modify @index during the
- * iteration if you want to skip or reprocess indices. It is safe to modify
- * the array during the iteration. At the end of the iteration, @entry will
- * be set to NULL and @index will have a value less than or equal to max.
+ * During the iteration, @entry will have the value of the entry stored
+ * in @xa at @index. You may modify @index during the iteration if you want
+ * to skip or reprocess indices. It is safe to modify the array during the
+ * iteration. At the end of the iteration, @entry will be set to NULL and
+ * @index will have a value less than or equal to max.
*
* xa_for_each() is O(n.log(n)) while xas_for_each() is O(n). You have
* to handle your own locking with xas_for_each(), and if you have to unlock
@@ -366,9 +409,36 @@ static inline bool xa_marked(const struct xarray *xa, xa_mark_t mark)
*
* Context: Any context. Takes and releases the RCU lock.
*/
-#define xa_for_each(xa, entry, index, max, filter) \
- for (entry = xa_find(xa, &index, max, filter); entry; \
- entry = xa_find_after(xa, &index, max, filter))
+#define xa_for_each(xa, index, entry) \
+ xa_for_each_start(xa, index, entry, 0)
+
+/**
+ * xa_for_each_marked() - Iterate over marked entries in an XArray.
+ * @xa: XArray.
+ * @index: Index of @entry.
+ * @entry: Entry retrieved from array.
+ * @filter: Selection criterion.
+ *
+ * During the iteration, @entry will have the value of the entry stored
+ * in @xa at @index. The iteration will skip all entries in the array
+ * which do not match @filter. You may modify @index during the iteration
+ * if you want to skip or reprocess indices. It is safe to modify the array
+ * during the iteration. At the end of the iteration, @entry will be set to
+ * NULL and @index will have a value less than or equal to max.
+ *
+ * xa_for_each_marked() is O(n.log(n)) while xas_for_each_marked() is O(n).
+ * You have to handle your own locking with xas_for_each(), and if you have
+ * to unlock after each iteration, it will also end up being O(n.log(n)).
+ * xa_for_each_marked() will spin if it hits a retry entry; if you intend to
+ * see retry entries, you should use the xas_for_each_marked() iterator
+ * instead. The xas_for_each_marked() iterator will expand into more inline
+ * code than xa_for_each_marked().
+ *
+ * Context: Any context. Takes and releases the RCU lock.
+ */
+#define xa_for_each_marked(xa, index, entry, filter) \
+ for (index = 0, entry = xa_find(xa, &index, ULONG_MAX, filter); \
+ entry; entry = xa_find_after(xa, &index, ULONG_MAX, filter))
#define xa_trylock(xa) spin_trylock(&(xa)->xa_lock)
#define xa_lock(xa) spin_lock(&(xa)->xa_lock)
@@ -393,40 +463,13 @@ void *__xa_erase(struct xarray *, unsigned long index);
void *__xa_store(struct xarray *, unsigned long index, void *entry, gfp_t);
void *__xa_cmpxchg(struct xarray *, unsigned long index, void *old,
void *entry, gfp_t);
+int __xa_insert(struct xarray *, unsigned long index, void *entry, gfp_t);
int __xa_alloc(struct xarray *, u32 *id, u32 max, void *entry, gfp_t);
int __xa_reserve(struct xarray *, unsigned long index, 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_insert() - Store this entry in the XArray unless another entry is
- * already present.
- * @xa: XArray.
- * @index: Index into array.
- * @entry: New entry.
- * @gfp: Memory allocation flags.
- *
- * If you would rather see the existing entry in the array, use __xa_cmpxchg().
- * This function is for users who don't care what the entry is, only that
- * one is present.
- *
- * Context: Any context. Expects xa_lock to be held on entry. May
- * release and reacquire xa_lock if the @gfp flags permit.
- * Return: 0 if the store succeeded. -EEXIST if another entry was present.
- * -ENOMEM if memory could not be allocated.
- */
-static inline int __xa_insert(struct xarray *xa, unsigned long index,
- void *entry, gfp_t gfp)
-{
- void *curr = __xa_cmpxchg(xa, index, NULL, entry, gfp);
- if (!curr)
- return 0;
- if (xa_is_err(curr))
- return xa_err(curr);
- return -EEXIST;
-}
-
-/**
* xa_store_bh() - Store this entry in the XArray.
* @xa: XArray.
* @index: Index into array.
@@ -453,7 +496,7 @@ static inline void *xa_store_bh(struct xarray *xa, unsigned long index,
}
/**
- * xa_store_irq() - Erase this entry from the XArray.
+ * xa_store_irq() - Store this entry in the XArray.
* @xa: XArray.
* @index: Index into array.
* @entry: New entry.
@@ -615,24 +658,83 @@ static inline void *xa_cmpxchg_irq(struct xarray *xa, unsigned long index,
* @entry: New entry.
* @gfp: Memory allocation flags.
*
- * If you would rather see the existing entry in the array, use xa_cmpxchg().
- * This function is for users who don't care what the entry is, only that
- * one is present.
+ * Inserting a NULL entry will store a reserved entry (like xa_reserve())
+ * if no entry is present. Inserting will fail if a reserved entry is
+ * present, even though loading from this index will return NULL.
*
- * Context: Process context. Takes and releases the xa_lock.
- * May sleep if the @gfp flags permit.
+ * Context: Any context. Takes and releases the xa_lock. May sleep if
+ * the @gfp flags permit.
* Return: 0 if the store succeeded. -EEXIST if another entry was present.
* -ENOMEM if memory could not be allocated.
*/
static inline int xa_insert(struct xarray *xa, unsigned long index,
void *entry, gfp_t gfp)
{
- void *curr = xa_cmpxchg(xa, index, NULL, entry, gfp);
- if (!curr)
- return 0;
- if (xa_is_err(curr))
- return xa_err(curr);
- return -EEXIST;
+ int err;
+
+ xa_lock(xa);
+ err = __xa_insert(xa, index, entry, gfp);
+ xa_unlock(xa);
+
+ return err;
+}
+
+/**
+ * xa_insert_bh() - Store this entry in the XArray unless another entry is
+ * already present.
+ * @xa: XArray.
+ * @index: Index into array.
+ * @entry: New entry.
+ * @gfp: Memory allocation flags.
+ *
+ * Inserting a NULL entry will store a reserved entry (like xa_reserve())
+ * if no entry is present. Inserting will fail if a reserved entry is
+ * present, even though loading from this index will return NULL.
+ *
+ * Context: Any context. Takes and releases the xa_lock while
+ * disabling softirqs. May sleep if the @gfp flags permit.
+ * Return: 0 if the store succeeded. -EEXIST if another entry was present.
+ * -ENOMEM if memory could not be allocated.
+ */
+static inline int xa_insert_bh(struct xarray *xa, unsigned long index,
+ void *entry, gfp_t gfp)
+{
+ int err;
+
+ xa_lock_bh(xa);
+ err = __xa_insert(xa, index, entry, gfp);
+ xa_unlock_bh(xa);
+
+ return err;
+}
+
+/**
+ * xa_insert_irq() - Store this entry in the XArray unless another entry is
+ * already present.
+ * @xa: XArray.
+ * @index: Index into array.
+ * @entry: New entry.
+ * @gfp: Memory allocation flags.
+ *
+ * Inserting a NULL entry will store a reserved entry (like xa_reserve())
+ * if no entry is present. Inserting will fail if a reserved entry is
+ * present, even though loading from this index will return NULL.
+ *
+ * Context: Process context. Takes and releases the xa_lock while
+ * disabling interrupts. May sleep if the @gfp flags permit.
+ * Return: 0 if the store succeeded. -EEXIST if another entry was present.
+ * -ENOMEM if memory could not be allocated.
+ */
+static inline int xa_insert_irq(struct xarray *xa, unsigned long index,
+ void *entry, gfp_t gfp)
+{
+ int err;
+
+ xa_lock_irq(xa);
+ err = __xa_insert(xa, index, entry, gfp);
+ xa_unlock_irq(xa);
+
+ return err;
}
/**
@@ -970,8 +1072,8 @@ static inline bool xa_is_sibling(const void *entry)
(entry < xa_mk_sibling(XA_CHUNK_SIZE - 1));
}
-#define XA_ZERO_ENTRY xa_mk_internal(256)
-#define XA_RETRY_ENTRY xa_mk_internal(257)
+#define XA_RETRY_ENTRY xa_mk_internal(256)
+#define XA_ZERO_ENTRY xa_mk_internal(257)
/**
* xa_is_zero() - Is the entry a zero entry?
@@ -996,6 +1098,17 @@ static inline bool xa_is_retry(const void *entry)
}
/**
+ * xa_is_advanced() - Is the entry only permitted for the advanced API?
+ * @entry: Entry to be stored in the XArray.
+ *
+ * Return: %true if the entry cannot be stored by the normal API.
+ */
+static inline bool xa_is_advanced(const void *entry)
+{
+ return xa_is_internal(entry) && (entry <= XA_RETRY_ENTRY);
+}
+
+/**
* typedef xa_update_node_t - A callback function from the XArray.
* @node: The node which is being processed
*
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 4676c0a1eeca..c596a957f764 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -199,7 +199,7 @@ static noinline void check_xa_mark_1(struct xarray *xa, unsigned long index)
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_set_mark(xa, index + 2, XA_MARK_2);
XA_BUG_ON(xa, xa_store_index(xa, next, GFP_KERNEL));
xa_store_order(xa, index, order, xa_mk_index(index),
GFP_KERNEL);
@@ -209,8 +209,8 @@ static noinline void check_xa_mark_1(struct xarray *xa, unsigned long index)
void *entry;
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, i, XA_MARK_1));
+ XA_BUG_ON(xa, !xa_get_mark(xa, i, XA_MARK_2));
/* We should see two elements in the array */
rcu_read_lock();
@@ -357,7 +357,7 @@ static noinline void check_cmpxchg(struct xarray *xa)
static noinline void check_reserve(struct xarray *xa)
{
void *entry;
- unsigned long index = 0;
+ unsigned long index;
/* An array with a reserved entry is not empty */
XA_BUG_ON(xa, !xa_empty(xa));
@@ -382,10 +382,12 @@ static noinline void check_reserve(struct xarray *xa)
xa_erase_index(xa, 12345678);
XA_BUG_ON(xa, !xa_empty(xa));
- /* And so does xa_insert */
+ /* But xa_insert does not */
xa_reserve(xa, 12345678, GFP_KERNEL);
- XA_BUG_ON(xa, xa_insert(xa, 12345678, xa_mk_value(12345678), 0) != 0);
- xa_erase_index(xa, 12345678);
+ XA_BUG_ON(xa, xa_insert(xa, 12345678, xa_mk_value(12345678), 0) !=
+ -EEXIST);
+ XA_BUG_ON(xa, xa_empty(xa));
+ XA_BUG_ON(xa, xa_erase(xa, 12345678) != NULL);
XA_BUG_ON(xa, !xa_empty(xa));
/* Can iterate through a reserved entry */
@@ -393,7 +395,7 @@ static noinline void check_reserve(struct xarray *xa)
xa_reserve(xa, 6, GFP_KERNEL);
xa_store_index(xa, 7, GFP_KERNEL);
- xa_for_each(xa, entry, index, ULONG_MAX, XA_PRESENT) {
+ xa_for_each(xa, index, entry) {
XA_BUG_ON(xa, index != 5 && index != 7);
}
xa_destroy(xa);
@@ -812,17 +814,16 @@ static noinline void check_find_1(struct xarray *xa)
static noinline void check_find_2(struct xarray *xa)
{
void *entry;
- unsigned long i, j, index = 0;
+ unsigned long i, j, index;
- xa_for_each(xa, entry, index, ULONG_MAX, XA_PRESENT) {
+ xa_for_each(xa, index, entry) {
XA_BUG_ON(xa, true);
}
for (i = 0; i < 1024; i++) {
xa_store_index(xa, index, GFP_KERNEL);
j = 0;
- index = 0;
- xa_for_each(xa, entry, index, ULONG_MAX, XA_PRESENT) {
+ xa_for_each(xa, index, entry) {
XA_BUG_ON(xa, xa_mk_index(index) != entry);
XA_BUG_ON(xa, index != j++);
}
@@ -839,6 +840,7 @@ static noinline void check_find_3(struct xarray *xa)
for (i = 0; i < 100; i++) {
for (j = 0; j < 100; j++) {
+ rcu_read_lock();
for (k = 0; k < 100; k++) {
xas_set(&xas, j);
xas_for_each_marked(&xas, entry, k, XA_MARK_0)
@@ -847,6 +849,7 @@ static noinline void check_find_3(struct xarray *xa)
XA_BUG_ON(xa,
xas.xa_node != XAS_RESTART);
}
+ rcu_read_unlock();
}
xa_store_index(xa, i, GFP_KERNEL);
xa_set_mark(xa, i, XA_MARK_0);
@@ -1183,6 +1186,35 @@ static noinline void check_store_range(struct xarray *xa)
}
}
+static void check_align_1(struct xarray *xa, char *name)
+{
+ int i;
+ unsigned int id;
+ unsigned long index;
+ void *entry;
+
+ for (i = 0; i < 8; i++) {
+ id = 0;
+ XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, name + i, GFP_KERNEL)
+ != 0);
+ XA_BUG_ON(xa, id != i);
+ }
+ xa_for_each(xa, index, entry)
+ XA_BUG_ON(xa, xa_is_err(entry));
+ xa_destroy(xa);
+}
+
+static noinline void check_align(struct xarray *xa)
+{
+ char name[] = "Motorola 68000";
+
+ check_align_1(xa, name);
+ check_align_1(xa, name + 1);
+ check_align_1(xa, name + 2);
+ check_align_1(xa, name + 3);
+// check_align_2(xa, name);
+}
+
static LIST_HEAD(shadow_nodes);
static void test_update_node(struct xa_node *node)
@@ -1332,6 +1364,7 @@ static int xarray_checks(void)
check_create_range(&array);
check_store_range(&array);
check_store_iter(&array);
+ check_align(&xa0);
check_workingset(&array, 0);
check_workingset(&array, 64);
diff --git a/lib/xarray.c b/lib/xarray.c
index 5f3f9311de89..81c3171ddde9 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -232,6 +232,8 @@ void *xas_load(struct xa_state *xas)
if (xas->xa_shift > node->shift)
break;
entry = xas_descend(xas, node);
+ if (node->shift == 0)
+ break;
}
return entry;
}
@@ -506,7 +508,7 @@ static void xas_free_nodes(struct xa_state *xas, struct xa_node *top)
for (;;) {
void *entry = xa_entry_locked(xas->xa, node, offset);
- if (xa_is_node(entry)) {
+ if (node->shift && xa_is_node(entry)) {
node = xa_to_node(entry);
offset = 0;
continue;
@@ -604,6 +606,7 @@ static int xas_expand(struct xa_state *xas, void *head)
/*
* xas_create() - Create a slot to store an entry in.
* @xas: XArray operation state.
+ * @allow_root: %true if we can store the entry in the root directly
*
* 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
@@ -613,7 +616,7 @@ static int xas_expand(struct xa_state *xas, void *head)
* 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)
+static void *xas_create(struct xa_state *xas, bool allow_root)
{
struct xarray *xa = xas->xa;
void *entry;
@@ -628,6 +631,8 @@ static void *xas_create(struct xa_state *xas)
shift = xas_expand(xas, entry);
if (shift < 0)
return NULL;
+ if (!shift && !allow_root)
+ shift = XA_CHUNK_SHIFT;
entry = xa_head_locked(xa);
slot = &xa->xa_head;
} else if (xas_error(xas)) {
@@ -687,7 +692,7 @@ void xas_create_range(struct xa_state *xas)
xas->xa_sibs = 0;
for (;;) {
- xas_create(xas);
+ xas_create(xas, true);
if (xas_error(xas))
goto restore;
if (xas->xa_index <= (index | XA_CHUNK_MASK))
@@ -754,7 +759,7 @@ void *xas_store(struct xa_state *xas, void *entry)
bool value = xa_is_value(entry);
if (entry)
- first = xas_create(xas);
+ first = xas_create(xas, !xa_is_node(entry));
else
first = xas_load(xas);
@@ -1251,35 +1256,6 @@ void *xas_find_conflict(struct xa_state *xas)
EXPORT_SYMBOL_GPL(xas_find_conflict);
/**
- * xa_init_flags() - Initialise an empty XArray with flags.
- * @xa: XArray.
- * @flags: XA_FLAG values.
- *
- * If you need to initialise an XArray with special flags (eg you need
- * to take the lock from interrupt context), use this function instead
- * of xa_init().
- *
- * Context: Any context.
- */
-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);
-
-/**
* xa_load() - Load an entry from an XArray.
* @xa: XArray.
* @index: index into array.
@@ -1308,7 +1284,6 @@ static void *xas_result(struct xa_state *xas, void *curr)
{
if (xa_is_zero(curr))
return NULL;
- XA_NODE_BUG_ON(xas->xa_node, xa_is_internal(curr));
if (xas_error(xas))
curr = xas->xa_node;
return curr;
@@ -1378,7 +1353,7 @@ 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)))
+ if (WARN_ON_ONCE(xa_is_advanced(entry)))
return XA_ERROR(-EINVAL);
if (xa_track_free(xa) && !entry)
entry = XA_ZERO_ENTRY;
@@ -1444,7 +1419,7 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
XA_STATE(xas, xa, index);
void *curr;
- if (WARN_ON_ONCE(xa_is_internal(entry)))
+ if (WARN_ON_ONCE(xa_is_advanced(entry)))
return XA_ERROR(-EINVAL);
if (xa_track_free(xa) && !entry)
entry = XA_ZERO_ENTRY;
@@ -1465,6 +1440,47 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
EXPORT_SYMBOL(__xa_cmpxchg);
/**
+ * __xa_insert() - Store this entry in the XArray if no entry is present.
+ * @xa: XArray.
+ * @index: Index into array.
+ * @entry: New entry.
+ * @gfp: Memory allocation flags.
+ *
+ * Inserting a NULL entry will store a reserved entry (like xa_reserve())
+ * if no entry is present. Inserting will fail if a reserved entry is
+ * present, even though loading from this index will return NULL.
+ *
+ * Context: Any context. Expects xa_lock to be held on entry. May
+ * release and reacquire xa_lock if @gfp flags permit.
+ * Return: 0 if the store succeeded. -EEXIST if another entry was present.
+ * -ENOMEM if memory could not be allocated.
+ */
+int __xa_insert(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
+{
+ XA_STATE(xas, xa, index);
+ void *curr;
+
+ if (WARN_ON_ONCE(xa_is_advanced(entry)))
+ return -EINVAL;
+ if (!entry)
+ entry = XA_ZERO_ENTRY;
+
+ do {
+ curr = xas_load(&xas);
+ if (!curr) {
+ xas_store(&xas, entry);
+ if (xa_track_free(xa))
+ xas_clear_mark(&xas, XA_FREE_MARK);
+ } else {
+ xas_set_err(&xas, -EEXIST);
+ }
+ } while (__xas_nomem(&xas, gfp));
+
+ return xas_error(&xas);
+}
+EXPORT_SYMBOL(__xa_insert);
+
+/**
* __xa_reserve() - Reserve this index in the XArray.
* @xa: XArray.
* @index: Index into array.
@@ -1567,7 +1583,7 @@ void *xa_store_range(struct xarray *xa, unsigned long first,
if (last + 1)
order = __ffs(last + 1);
xas_set_order(&xas, last, order);
- xas_create(&xas);
+ xas_create(&xas, true);
if (xas_error(&xas))
goto unlock;
}
@@ -1609,7 +1625,7 @@ int __xa_alloc(struct xarray *xa, u32 *id, u32 max, void *entry, gfp_t gfp)
XA_STATE(xas, xa, 0);
int err;
- if (WARN_ON_ONCE(xa_is_internal(entry)))
+ if (WARN_ON_ONCE(xa_is_advanced(entry)))
return -EINVAL;
if (WARN_ON_ONCE(!xa_track_free(xa)))
return -EINVAL;