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-rw-r--r--lib/errseq.c23
1 files changed, 9 insertions, 14 deletions
diff --git a/lib/errseq.c b/lib/errseq.c
index df782418b333..81f9e33aa7e7 100644
--- a/lib/errseq.c
+++ b/lib/errseq.c
@@ -111,27 +111,22 @@ EXPORT_SYMBOL(errseq_set);
* errseq_sample() - Grab current errseq_t value.
* @eseq: Pointer to errseq_t to be sampled.
*
- * This function allows callers to sample an errseq_t value, marking it as
- * "seen" if required.
+ * This function allows callers to initialise their errseq_t variable.
+ * If the error has been "seen", new callers will not see an old error.
+ * If there is an unseen error in @eseq, the caller of this function will
+ * see it the next time it checks for an error.
*
+ * Context: Any context.
* Return: The current errseq value.
*/
errseq_t errseq_sample(errseq_t *eseq)
{
errseq_t old = READ_ONCE(*eseq);
- errseq_t new = old;
- /*
- * For the common case of no errors ever having been set, we can skip
- * marking the SEEN bit. Once an error has been set, the value will
- * never go back to zero.
- */
- if (old != 0) {
- new |= ERRSEQ_SEEN;
- if (old != new)
- cmpxchg(eseq, old, new);
- }
- return new;
+ /* If nobody has seen this error yet, then we can be the first. */
+ if (!(old & ERRSEQ_SEEN))
+ old = 0;
+ return old;
}
EXPORT_SYMBOL(errseq_sample);