Use fdatasync (just for testing over an FS)

blockstore_flush.cpp

@@ -353,14 +353,14 @@ resume_0:
                 await_sqe(9);
                 data->callback = simple_callback;
                 data->iov = { 0 };
-                my_uring_prep_fsync(sqe, bs->data_fd, 0);
+                my_uring_prep_fsync(sqe, bs->data_fd, IORING_FSYNC_DATASYNC);
                 wait_count++;
                 if (bs->meta_fd != bs->data_fd)
                 {
                     await_sqe(10);
                     data->callback = simple_callback;
                     data->iov = { 0 };
-                    my_uring_prep_fsync(sqe, bs->meta_fd, 0);
+                    my_uring_prep_fsync(sqe, bs->meta_fd, IORING_FSYNC_DATASYNC);
                     wait_count++;
                 }
                 wait_state = 11;

blockstore_init.cpp

@@ -206,7 +206,7 @@ resume_1:
         my_uring_prep_writev(sqe, bs->journal.fd, &data->iov, 1, bs->journal.offset);
         wait_count++;
         GET_SQE();
-        my_uring_prep_fsync(sqe, bs->journal.fd, 0);
+        my_uring_prep_fsync(sqe, bs->journal.fd, IORING_FSYNC_DATASYNC);
         data->iov = { 0 };
         data->callback = simple_callback;
         wait_count++;

blockstore_stable.cpp

@@ -7,9 +7,9 @@
 //
 // This makes 1 4K small write+sync look like:
 // 512b+4K (journal) + sync + 512b (journal) + sync + 4K (data) [+ sync?] + 512b (metadata) + sync.
-// WA = 2.375. It's not the best, SSD FTL-like redirect-write with defragmentation
-// could probably be lower even with defragmentation. But it's fixed and it's still
-// better than in Ceph. :) except for HDD-only clusters, because each write results in 3 seeks.
+// WA = 2.375. It's not the best, SSD FTL-like redirect-write could probably be lower
+// even with defragmentation. But it's fixed and it's still better than in Ceph. :)
+// except for HDD-only clusters, because each write results in 3 seeks.
 
 // Stabilize big write:
 // 1) Copy metadata from the journal to the metadata device

blockstore_sync.cpp

@@ -41,7 +41,7 @@ int blockstore::continue_sync(blockstore_operation *op)
         // No big writes, just fsync the journal
         // FIXME: Add no-fsync mode
         BS_SUBMIT_GET_SQE(sqe, data);
-        my_uring_prep_fsync(sqe, journal.fd, 0);
+        my_uring_prep_fsync(sqe, journal.fd, IORING_FSYNC_DATASYNC);
         data->iov = { 0 };
         data->callback = cb;
         op->min_used_journal_sector = op->max_used_journal_sector = 0;
@@ -53,7 +53,7 @@ int blockstore::continue_sync(blockstore_operation *op)
         // 1st step: fsync data
         // FIXME: Add no-fsync mode
         BS_SUBMIT_GET_SQE(sqe, data);
-        my_uring_prep_fsync(sqe, data_fd, 0);
+        my_uring_prep_fsync(sqe, data_fd, IORING_FSYNC_DATASYNC);
         data->iov = { 0 };
         data->callback = cb;
         op->min_used_journal_sector = op->max_used_journal_sector = 0;
@@ -100,7 +100,7 @@ int blockstore::continue_sync(blockstore_operation *op)
         }
         op->max_used_journal_sector = 1 + journal.cur_sector;
         // ... And a journal fsync
-        my_uring_prep_fsync(sqe[s], journal.fd, 0);
+        my_uring_prep_fsync(sqe[s], journal.fd, IORING_FSYNC_DATASYNC);
         struct ring_data_t *data = ((ring_data_t*)sqe[s]->user_data);
         data->iov = { 0 };
         data->callback = cb;