block: rename buffer_alignment to guest_block_size

The alignment field is now set to the value that is promised to the
guest, rather than required by the host.  The next patches will make
QEMU aware of the host-provided values, so make this clear.

The alignment is also not about memory buffers, but about the sectors on
the disk, change the documentation of the field.

At this point, the field is set by the device emulation, but completely
ignored by the block layer.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>

1 files changed, 5 insertions, 5 deletions

diff --git a/block.c b/block.c
index e5f214d135..195beff706 100644
--- a/block.c
+++ b/block.c
@@ -851,7 +851,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     }
 
     bs->open_flags = flags;
-    bs->buffer_alignment = 512;
+    bs->guest_block_size = 512;
     bs->zero_beyond_eof = true;
     open_flags = bdrv_open_flags(bs, flags);
     bs->read_only = !(open_flags & BDRV_O_RDWR);
@@ -1796,7 +1796,7 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
     bs_dest->dev_ops            = bs_src->dev_ops;
     bs_dest->dev_opaque         = bs_src->dev_opaque;
     bs_dest->dev                = bs_src->dev;
-    bs_dest->buffer_alignment   = bs_src->buffer_alignment;
+    bs_dest->guest_block_size   = bs_src->guest_block_size;
     bs_dest->copy_on_read       = bs_src->copy_on_read;
 
     bs_dest->enable_write_cache = bs_src->enable_write_cache;
@@ -1953,7 +1953,7 @@ void bdrv_detach_dev(BlockDriverState *bs, void *dev)
     bs->dev = NULL;
     bs->dev_ops = NULL;
     bs->dev_opaque = NULL;
-    bs->buffer_alignment = 512;
+    bs->guest_block_size = 512;
 }
 
 /* TODO change to return DeviceState * when all users are qdevified */
@@ -4806,9 +4806,9 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
     return NULL;
 }
 
-void bdrv_set_buffer_alignment(BlockDriverState *bs, int align)
+void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
 {
-    bs->buffer_alignment = align;
+    bs->guest_block_size = align;
 }
 
 void *qemu_blockalign(BlockDriverState *bs, size_t size)