libminixfs: do not make fs_sync upcalls

The file system may not be expecting these upcalls at arbitrary
moments, while they serve only as a performance optimization anyway.

Change-Id: I0748fd1f6c2645ddbb64466093ee36025aac45e0

minix/include/minix/libminixfs.h

@@ -59,7 +59,6 @@ void lmfs_blockschange(dev_t dev, int delta);
 
 /* calls that libminixfs does into fs */
 void fs_blockstats(u64_t *blocks, u64_t *free, u64_t *used);
-int fs_sync(void);
 
 /* get_block arguments */
 #define NORMAL             0    /* forces get_block to do disk read */

minix/lib/libminixfs/cache.c

@@ -854,7 +854,7 @@ void lmfs_buf_pool(int new_nr_bufs)
 
   if(nr_bufs > 0) {
 	assert(buf);
-	(void) fs_sync();
+	lmfs_flushall();
   	for (bp = &buf[0]; bp < &buf[nr_bufs]; bp++) {
 		if(bp->data) {
 			assert(bp->lmfs_bytes > 0);

minix/tests/test72.c

@@ -90,12 +90,6 @@ void testend(void)
 
 /* Fake some libminixfs client functions */
 
-int
-fs_sync(void)
-{
-	return 0;
-}
-
 void
 fs_blockstats(u64_t *total, u64_t *free, u64_t *used)
 {