stress-aio-linux: fix error handling and submit waits, add sanity dat…

…a checks

Clean up the submit wait handling and add data sanity checking. This
allows us to see if we are stomping over pending async io requests.

Kudos to Vincent Chen for reporting the issue and suggesting the
data sanity checking.

Signed-off-by: Colin Ian King <colin.king@canonical.com>

stress-aio-linux.c

@@ -107,6 +107,24 @@ static inline void aio_linux_fill_buffer(
 		buffer[i] = (uint8_t)(request + i);
 }
 
+/*
+ *  aio_linux_check_buffer()
+ *	check buffer contains some known pattern
+ */
+static inline bool aio_linux_check_buffer(
+	const int request,
+	uint8_t *const buffer,
+	const size_t size)
+{
+	register size_t i;
+
+	for (i = 0; i < size; i++)
+		if (buffer[i] != (uint8_t)(request + i))
+			return false;
+
+	return true;
+}
+
 /*
  *  stress_aiol_submit()
  *	submit async I/O requests
@@ -386,13 +404,14 @@ static int stress_aiol(const stress_args_t *args)
 	j = 0;
 	do {
 		uint8_t *bufptr;
+		int n;
 
 		/*
 		 *  async writes
 		 */
 		(void)memset(cb, 0, aio_linux_requests * sizeof(*cb));
 		for (bufptr = buffer, i = 0; i < aio_linux_requests; i++, bufptr += BUFFER_SZ) {
-			aio_linux_fill_buffer(i, bufptr, BUFFER_SZ);
+			aio_linux_fill_buffer(i + j, bufptr, BUFFER_SZ);
 
 			cb[i].aio_fildes = fds[i];
 			cb[i].aio_lio_opcode = IO_CMD_PWRITE;
@@ -414,7 +433,7 @@ static int stress_aiol(const stress_args_t *args)
 		 */
 		(void)memset(cb, 0, aio_linux_requests * sizeof(*cb));
 		for (bufptr = buffer, i = 0; i < aio_linux_requests; i++, bufptr += BUFFER_SZ) {
-			aio_linux_fill_buffer(i, bufptr, BUFFER_SZ);
+			(void)memset(bufptr, 0, BUFFER_SZ);
 
 			cb[i].aio_fildes = fds[i];
 			cb[i].aio_lio_opcode = IO_CMD_PREAD;
@@ -440,8 +459,17 @@ static int stress_aiol(const stress_args_t *args)
 			}
 		}
 #endif
-		if (stress_aiol_wait(args, ctx, events, aio_linux_requests) < 0)
+		n = stress_aiol_wait(args, ctx, events, aio_linux_requests);
+		if (n < 0)
 			break;
+
+		for (bufptr = buffer, i = 0; i < (size_t)n ; i++, bufptr += BUFFER_SZ) {
+			if (aio_linux_check_buffer(i + j, bufptr, BUFFER_SZ) != true) {
+				pr_fail("%s: data mismatch in buffer %zd\n",
+					args->name, i);
+			}
+		}
+
 		inc_counter(args);
 		if (!keep_stressing())
 			break;
@@ -458,7 +486,8 @@ static int stress_aiol(const stress_args_t *args)
 			cb[i].u.c.nbytes = ~0;	/* invalid */
 			cbs[i] = &cb[i];
 		}
-		(void)stress_aiol_submit(args, ctx, cbs, aio_linux_requests, true);
+		if (stress_aiol_submit(args, ctx, cbs, aio_linux_requests, true) < 0)
+			break;
 		if (errno == 0)
 			(void)stress_aiol_wait(args, ctx, events, aio_linux_requests);
 		inc_counter(args);