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authorMatthew Wilcox <willy@infradead.org>2018-10-30 14:45:55 +0100
committerMatthew Wilcox <willy@infradead.org>2018-11-05 22:38:08 +0100
commit4c0608f4a0e76dfb82d3accd20081f4bf47ed143 (patch)
tree54a22dbdebdd23830ea5c9f88c78cdc8567f2fef /lib
parentnilfs2: Use xa_erase_irq (diff)
downloadlinux-4c0608f4a0e76dfb82d3accd20081f4bf47ed143.tar.xz
linux-4c0608f4a0e76dfb82d3accd20081f4bf47ed143.zip
XArray: Regularise xa_reserve
The xa_reserve() function was a little unusual in that it attempted to be callable for all kinds of locking scenarios. Make it look like the other APIs with __xa_reserve, xa_reserve_bh and xa_reserve_irq variants. Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/test_xarray.c6
-rw-r--r--lib/xarray.c18
2 files changed, 13 insertions, 11 deletions
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 126127658b49..e5294b20b52f 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -373,6 +373,12 @@ 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 */
+ 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_empty(xa));
+
/* Can iterate through a reserved entry */
xa_store_index(xa, 5, GFP_KERNEL);
xa_reserve(xa, 6, GFP_KERNEL);
diff --git a/lib/xarray.c b/lib/xarray.c
index e7be4e47c6a9..9cab8cfef8a8 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1488,7 +1488,7 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
EXPORT_SYMBOL(__xa_cmpxchg);
/**
- * xa_reserve() - Reserve this index in the XArray.
+ * __xa_reserve() - Reserve this index in the XArray.
* @xa: XArray.
* @index: Index into array.
* @gfp: Memory allocation flags.
@@ -1496,33 +1496,29 @@ EXPORT_SYMBOL(__xa_cmpxchg);
* Ensures there is somewhere to store an entry at @index in the array.
* If there is already something stored at @index, this function does
* nothing. If there was nothing there, the entry is marked as reserved.
- * Loads from @index will continue to see a %NULL pointer until a
- * subsequent store to @index.
+ * Loading from a reserved entry returns a %NULL pointer.
*
* If you do not use the entry that you have reserved, call xa_release()
* or xa_erase() to free any unnecessary memory.
*
- * Context: Process context. Takes and releases the xa_lock, IRQ or BH safe
- * if specified in XArray flags. May sleep if the @gfp flags permit.
+ * Context: Any context. Expects the xa_lock to be held on entry. May
+ * release the lock, sleep and reacquire the lock if the @gfp flags permit.
* Return: 0 if the reservation succeeded or -ENOMEM if it failed.
*/
-int xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp)
+int __xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp)
{
XA_STATE(xas, xa, index);
- unsigned int lock_type = xa_lock_type(xa);
void *curr;
do {
- xas_lock_type(&xas, lock_type);
curr = xas_load(&xas);
if (!curr)
xas_store(&xas, XA_ZERO_ENTRY);
- xas_unlock_type(&xas, lock_type);
- } while (xas_nomem(&xas, gfp));
+ } while (__xas_nomem(&xas, gfp));
return xas_error(&xas);
}
-EXPORT_SYMBOL(xa_reserve);
+EXPORT_SYMBOL(__xa_reserve);
#ifdef CONFIG_XARRAY_MULTI
static void xas_set_range(struct xa_state *xas, unsigned long first,