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-rw-r--r--lib/xarray.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/lib/xarray.c b/lib/xarray.c
index 9644b18af18d..76dde3a1cacf 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1742,20 +1742,23 @@ static inline void *__xa_cmpxchg_raw(struct xarray *xa, unsigned long index,
void *old, void *entry, gfp_t gfp);
/**
- * __xa_cmpxchg() - Store this entry in the XArray.
+ * __xa_cmpxchg() - Conditionally replace an entry in the XArray.
* @xa: XArray.
* @index: Index into array.
* @old: Old value to test against.
- * @entry: New entry.
+ * @entry: New value to place in array.
* @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.
*
+ * If the entry at @index is the same as @old, replace it with @entry.
+ * If the return value is equal to @old, then the exchange was successful.
+ *
* 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.
+ * Return: The old value at this index or xa_err() if an error happened.
*/
void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
void *old, void *entry, gfp_t gfp)