block/file-posix.c: Fix unused variable warning on OpenBSD

On OpenBSD none of the ioctls probe_logical_blocksize() tries
exist, so the variable sector_size is unused. Refactor the
code to avoid this (and reduce the duplicated code).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 1490279788-12995-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Max Reitz <mreitz@redhat.com>

diff --git a/block/file-posix.c b/block/file-posix.c
index beb7a4f728206fbb6f57db3c8e98bc84de1d4169..0841a08785aa5a9df95087387f33020bf64998ab 100644 (file)
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -220,28 +220,28 @@ static int probe_logical_blocksize(int fd, unsigned int *sector_size_p)
 {
     unsigned int sector_size;
     bool success = false;
+    int i;
 
     errno = ENOTSUP;
-
-    /* Try a few ioctls to get the right size */
+    static const unsigned long ioctl_list[] = {
 #ifdef BLKSSZGET
-    if (ioctl(fd, BLKSSZGET, &sector_size) >= 0) {
-        *sector_size_p = sector_size;
-        success = true;
-    }
+        BLKSSZGET,
 #endif
 #ifdef DKIOCGETBLOCKSIZE
-    if (ioctl(fd, DKIOCGETBLOCKSIZE, &sector_size) >= 0) {
-        *sector_size_p = sector_size;
-        success = true;
-    }
+        DKIOCGETBLOCKSIZE,
 #endif
 #ifdef DIOCGSECTORSIZE
-    if (ioctl(fd, DIOCGSECTORSIZE, &sector_size) >= 0) {
-        *sector_size_p = sector_size;
-        success = true;
-    }
+        DIOCGSECTORSIZE,
 #endif
+    };
+
+    /* Try a few ioctls to get the right size */
+    for (i = 0; i < (int)ARRAY_SIZE(ioctl_list); i++) {
+        if (ioctl(fd, ioctl_list[i], &sector_size) >= 0) {
+            *sector_size_p = sector_size;
+            success = true;
+        }
+    }
 
     return success ? 0 : -errno;
 }