diff mbox

[PULL,05/41] block: add wrappers for logical block provisioning information

Message ID 1385743555-27888-6-git-send-email-kwolf@redhat.com
State New
Headers show

Commit Message

Kevin Wolf Nov. 29, 2013, 4:45 p.m. UTC 
From: Peter Lieven <pl@kamp.de>

This adds 2 wrappers to read the unallocated_blocks_are_zero and
can_write_zeroes_with_unmap info from the BDI. The wrappers are
required to check for the existence of a backing_hd and
if the devices are opened with the correct flags.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block.c               | 30 ++++++++++++++++++++++++++++++
 include/block/block.h |  2 ++
 2 files changed, 32 insertions(+)
diff mbox

Patch

diff --git a/block.c b/block.c
index d34e974..3759582 100644
--- a/block.c
+++ b/block.c
@@ -3103,6 +3103,36 @@  int bdrv_has_zero_init(BlockDriverState *bs)
     return 0;
 }
 
+bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
+{
+    BlockDriverInfo bdi;
+
+    if (bs->backing_hd) {
+        return false;
+    }
+
+    if (bdrv_get_info(bs, &bdi) == 0) {
+        return bdi.unallocated_blocks_are_zero;
+    }
+
+    return false;
+}
+
+bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
+{
+    BlockDriverInfo bdi;
+
+    if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) {
+        return false;
+    }
+
+    if (bdrv_get_info(bs, &bdi) == 0) {
+        return bdi.can_write_zeroes_with_unmap;
+    }
+
+    return false;
+}
+
 typedef struct BdrvCoGetBlockStatusData {
     BlockDriverState *bs;
     BlockDriverState *base;
diff --git a/include/block/block.h b/include/block/block.h
index 9c76967..803c5ca 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -344,6 +344,8 @@  int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors);
 int bdrv_has_zero_init_1(BlockDriverState *bs);
 int bdrv_has_zero_init(BlockDriverState *bs);
+bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs);
+bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs);
 int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num,
                               int nb_sectors, int *pnum);
 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,