Merge branch 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block:
  Properly notify block layer of sync writes
  block: Fix the starving writes bug in the anticipatory IO scheduler

block/as-iosched.c

@@ -831,6 +831,8 @@ static void as_completed_request(struct request_queue *q, struct request *rq)
 	}
 
 	if (ad->changed_batch && ad->nr_dispatched == 1) {
+		ad->current_batch_expires = jiffies +
+					ad->batch_expire[ad->batch_data_dir];
 		kblockd_schedule_work(&ad->antic_work);
 		ad->changed_batch = 0;
 

fs/buffer.c

@@ -821,7 +821,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 				 * contents - it is a noop if I/O is still in
 				 * flight on potentially older contents.
 				 */
-				ll_rw_block(SWRITE, 1, &bh);
+				ll_rw_block(SWRITE_SYNC, 1, &bh);
 				brelse(bh);
 				spin_lock(lock);
 			}
@@ -2940,15 +2940,18 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
 	for (i = 0; i < nr; i++) {
 		struct buffer_head *bh = bhs[i];
 
-		if (rw == SWRITE)
+		if (rw == SWRITE || rw == SWRITE_SYNC)
 			lock_buffer(bh);
 		else if (test_set_buffer_locked(bh))
 			continue;
 
-		if (rw == WRITE || rw == SWRITE) {
+		if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC) {
 			if (test_clear_buffer_dirty(bh)) {
 				bh->b_end_io = end_buffer_write_sync;
 				get_bh(bh);
+				if (rw == SWRITE_SYNC)
+					submit_bh(WRITE_SYNC, bh);
+				else
 					submit_bh(WRITE, bh);
 				continue;
 			}
@@ -2978,7 +2981,7 @@ int sync_dirty_buffer(struct buffer_head *bh)
 	if (test_clear_buffer_dirty(bh)) {
 		get_bh(bh);
 		bh->b_end_io = end_buffer_write_sync;
-		ret = submit_bh(WRITE, bh);
+		ret = submit_bh(WRITE_SYNC, bh);
 		wait_on_buffer(bh);
 		if (buffer_eopnotsupp(bh)) {
 			clear_buffer_eopnotsupp(bh);

include/linux/fs.h

@@ -83,6 +83,7 @@ extern int dir_notify_enable;
 #define READ_SYNC	(READ | (1 << BIO_RW_SYNC))
 #define READ_META	(READ | (1 << BIO_RW_META))
 #define WRITE_SYNC	(WRITE | (1 << BIO_RW_SYNC))
+#define SWRITE_SYNC	(SWRITE | (1 << BIO_RW_SYNC))
 #define WRITE_BARRIER	((1 << BIO_RW) | (1 << BIO_RW_BARRIER))
 
 #define SEL_IN		1