[Qemu-devel] [PATCH v3 03/13] file-posix: support BDRV_REQ_ALLOCATE

[Anton Nefedov <anton.nefedov@virtuozzo.com>]

Current write_zeroes implementation is good enough to satisfy this flag too

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
---
 block/file-posix.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index cfbb236..bd52b31 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -527,7 +527,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
 
     s->has_discard = true;
     s->has_write_zeroes = true;
-    bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
     if ((bs->open_flags & BDRV_O_NOCACHE) != 0) {
         s->needs_alignment = true;
     }
@@ -577,6 +576,11 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
     }
 #endif
 
+    bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
+    if (s->has_write_zeroes || s->has_fallocate) {
+        bs->supported_zero_flags |= BDRV_REQ_ALLOCATE;
+    }
+
     ret = 0;
 fail:
     if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
@@ -1390,6 +1394,9 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
     }
 #endif
 
+    if (!s->has_fallocate) {
+        aiocb->bs->supported_zero_flags &= ~BDRV_REQ_ALLOCATE;
+    }
     return -ENOTSUP;
 }
 
-- 
2.7.4