gluster: Return bdrv_has_zero_init = 0

PATCH New Kevin Wolf 1 participant 1 message Jun 26, 2013 Block layer

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Kevin Wolf

author

2013-06-26 07:47 UTC #0 lore raw

PATCH 1/1 gluster: Return bdrv_has_zero_init = 0

GlusterFS volumes can be backed by block devices, in which case bdrv_create() doesn't make sure that the image is zeroed out. It is currently not possibly to detect whether a given image is backed by a file or a block device, and incorrectly assuming that it is zeroed corrupts images during qemu-img convert, so let's err on the side of caution and always return 0.

Cc [email protected]

Signed-off-by Kevin Wolf <[email protected]>

---
 block/gluster.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

block/gluster.c +10 -0

index 91acde2..61424bc 100644
@@ -574,6 +574,12 @@ static void qemu_gluster_close(BlockDriverState *bs)
     glfs_fini(s->glfs);
 }
 
+static int qemu_gluster_has_zero_init(BlockDriverState *bs)
+{
+    /* GlusterFS volume could be backed by a block device */
+    return 0;
+}
+
 static QEMUOptionParameter qemu_gluster_create_options[] = {
     {
         .name = BLOCK_OPT_SIZE,

@@ -595,6 +601,7 @@ static BlockDriver bdrv_gluster = {
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
+    .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
     .create_options               = qemu_gluster_create_options,
 };

@@ -610,6 +617,7 @@ static BlockDriver bdrv_gluster_tcp = {
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
+    .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
     .create_options               = qemu_gluster_create_options,
 };

@@ -625,6 +633,7 @@ static BlockDriver bdrv_gluster_unix = {
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
+    .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
     .create_options               = qemu_gluster_create_options,
 };

@@ -640,6 +649,7 @@ static BlockDriver bdrv_gluster_rdma = {
     .bdrv_aio_readv               = qemu_gluster_aio_readv,
     .bdrv_aio_writev              = qemu_gluster_aio_writev,
     .bdrv_aio_flush               = qemu_gluster_aio_flush,
+    .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
     .create_options               = qemu_gluster_create_options,
 };

Signature · 1 line

1.8.1.4