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| author |   Matthew Wilcox <willy@infradead.org> | 2017-11-17 08:16:34 -0500 |
|---|---|---|
| committer | Matthew Wilcox <willy@infradead.org> | 2018-10-21 10:45:59 -0400 |
| commit | 687149fca1f37c447e5d161e0a4a04cb2c880cb6 (patch) | |
| tree | 5134bc243622997b10644a67a55ee51e6278930a /lib | |
| parent | xarray: Extract entries from an XArray (diff) | |
| download | linux-dev-687149fca1f37c447e5d161e0a4a04cb2c880cb6.tar.xz linux-dev-687149fca1f37c447e5d161e0a4a04cb2c880cb6.zip | |
xarray: Destroy an XArray
This function frees all the internal memory allocated to the xarray
and reinitialises it to be empty.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/test_xarray.c | 34 | ||||
| -rw-r--r-- | lib/xarray.c | 28 |
2 files changed, 62 insertions, 0 deletions
diff --git a/lib/test_xarray.c b/lib/test_xarray.c index e3c2d4d00b15..a96f67caa1c2 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -465,6 +465,39 @@ static noinline void check_find(struct xarray *xa) check_multi_find_2(xa); } +static noinline void check_destroy(struct xarray *xa) +{ + unsigned long index; + + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Destroying an empty array is a no-op */ + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Destroying an array with a single entry */ + for (index = 0; index < 1000; index++) { + xa_store_index(xa, index, GFP_KERNEL); + XA_BUG_ON(xa, xa_empty(xa)); + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); + } + + /* Destroying an array with a single entry at ULONG_MAX */ + xa_store(xa, ULONG_MAX, xa, GFP_KERNEL); + XA_BUG_ON(xa, xa_empty(xa)); + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); + +#ifdef CONFIG_XARRAY_MULTI + /* Destroying an array with a multi-index entry */ + xa_store_order(xa, 1 << 11, 11, xa, GFP_KERNEL); + XA_BUG_ON(xa, xa_empty(xa)); + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); +#endif +} + static DEFINE_XARRAY(array); static int xarray_checks(void) @@ -478,6 +511,7 @@ static int xarray_checks(void) check_cmpxchg(&array); check_multi_store(&array); check_find(&array); + check_destroy(&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 70e04810c8c2..057dbe0d3bf6 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -1524,6 +1524,34 @@ unsigned int xa_extract(struct xarray *xa, void **dst, unsigned long start, } EXPORT_SYMBOL(xa_extract); +/** + * xa_destroy() - Free all internal data structures. + * @xa: XArray. + * + * After calling this function, the XArray is empty and has freed all memory + * allocated for its internal data structures. You are responsible for + * freeing the objects referenced by the XArray. + * + * Context: Any context. Takes and releases the xa_lock, interrupt-safe. + */ +void xa_destroy(struct xarray *xa) +{ + XA_STATE(xas, xa, 0); + unsigned long flags; + void *entry; + + xas.xa_node = NULL; + xas_lock_irqsave(&xas, flags); + entry = xa_head_locked(xa); + RCU_INIT_POINTER(xa->xa_head, NULL); + xas_init_marks(&xas); + /* lockdep checks we're still holding the lock in xas_free_nodes() */ + if (xa_is_node(entry)) + xas_free_nodes(&xas, xa_to_node(entry)); + xas_unlock_irqrestore(&xas, flags); +} +EXPORT_SYMBOL(xa_destroy); + #ifdef XA_DEBUG void xa_dump_node(const struct xa_node *node) { |