[Qemu-devel] [PATCH] rbd: print a clear error message when write beyond EOF

[Jun Li]

Currently, as rbd driver do not support dynamic growth when write beyond EOF,
so just print a clear error message.

Signed-off-by: Jun Li <junm...@gmail.com>
---
 block/rbd.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/block/rbd.c b/block/rbd.c
index 5b5a64a..65b01f0 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -693,6 +693,20 @@ static BlockAIOCB *qemu_rbd_aio_writev(BlockDriverState 
*bs,
                                        BlockCompletionFunc *cb,
                                        void *opaque)
 {
+    BDRVRBDState *s = bs->opaque;
+    uint64_t total_size;
+    int64_t off, size;
+
+    off = sector_num * BDRV_SECTOR_SIZE;
+    size = nb_sectors * BDRV_SECTOR_SIZE;
+    rbd_get_size(s->image, &total_size);
+
+    if (off + size > total_size) {
+        fprintf(stdout, "Image formats that grow on demand"
+                        "are not supported on rbd.\n");
+        return NULL;
+    }
+
     return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque,
                          RBD_AIO_WRITE);
 }
-- 
1.9.3