block: Move request_alignment into BlockLimit

It makes more sense to have ALL block size limit constraints
in the same struct.  Improve the documentation while at it.

Simplify a couple of conditionals, now that we have audited and
documented that request_alignment is always non-zero.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/block/raw-posix.c b/block/raw-posix.c
index 8da2f94..d3d7cce 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -302,22 +302,22 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
     /* For SCSI generic devices the alignment is not really used.
        With buffered I/O, we don't have any restrictions. */
     if (bdrv_is_sg(bs) || !s->needs_alignment) {
-        bs->request_alignment = 1;
+        bs->bl.request_alignment = 1;
         s->buf_align = 1;
         return;
     }
 
-    bs->request_alignment = 0;
+    bs->bl.request_alignment = 0;
     s->buf_align = 0;
     /* Let's try to use the logical blocksize for the alignment. */
-    if (probe_logical_blocksize(fd, &bs->request_alignment) < 0) {
-        bs->request_alignment = 0;
+    if (probe_logical_blocksize(fd, &bs->bl.request_alignment) < 0) {
+        bs->bl.request_alignment = 0;
     }
 #ifdef CONFIG_XFS
     if (s->is_xfs) {
         struct dioattr da;
         if (xfsctl(NULL, fd, XFS_IOC_DIOINFO, &da) >= 0) {
-            bs->request_alignment = da.d_miniosz;
+            bs->bl.request_alignment = da.d_miniosz;
             /* The kernel returns wrong information for d_mem */
             /* s->buf_align = da.d_mem; */
         }
@@ -337,19 +337,19 @@ static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
         qemu_vfree(buf);
     }
 
-    if (!bs->request_alignment) {
+    if (!bs->bl.request_alignment) {
         size_t align;
         buf = qemu_memalign(s->buf_align, max_align);
         for (align = 512; align <= max_align; align <<= 1) {
             if (raw_is_io_aligned(fd, buf, align)) {
-                bs->request_alignment = align;
+                bs->bl.request_alignment = align;
                 break;
             }
         }
         qemu_vfree(buf);
     }
 
-    if (!s->buf_align || !bs->request_alignment) {
+    if (!s->buf_align || !bs->bl.request_alignment) {
         error_setg(errp, "Could not find working O_DIRECT alignment. "
                          "Try cache.direct=off.");
     }