lightnvm: pblk: warn in case of corrupted write buffer

[ Upstream commit e37d0798 ]

When cleaning up buffer entries as we wrap up, their state should be
"completed". If any of the entries is in "submitted" state, it means
that something bad has happened. Trigger a warning immediately instead of
waiting for the state flag to eventually be updated, thus hiding the
issue.
Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <mb@lightnvm.io>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/lightnvm/pblk-rb.c

@@ -142,10 +142,9 @@ static void clean_wctx(struct pblk_w_ctx *w_ctx)
 {
 	int flags;
 
-try:
 	flags = READ_ONCE(w_ctx->flags);
-	if (!(flags & PBLK_SUBMITTED_ENTRY))
-		goto try;
+	WARN_ONCE(!(flags & PBLK_SUBMITTED_ENTRY),
+			"pblk: overwriting unsubmitted data\n");
 
 	/* Release flags on context. Protect from writes and reads */
 	smp_store_release(&w_ctx->flags, PBLK_WRITABLE_ENTRY);