.has_zero_init defaults to 1 for all formats and protocols.
this is a dangerous default since this means that all
new added drivers need to manually overwrite it to 0 if
they do not ensure that a device is zero initialized
after bdrv_create().
if a driver needs to explicitly set this value to
1 its easier to verify the correctness in the review process.
during review of the existing drivers it turned out
that ssh and gluster had a wrong default of 1.
both protocols support host_devices as backend
which are not by default zero initialized. this
wrong assumption will lead to possible corruption
if qemu-img convert is used to write to such a backend.
a similar problem with the wrong default existed for
iscsi mose likely because the driver developer did
oversee the default value of 1.
Signed-off-by: Peter Lieven <p...@kamp.de>
---
block.c | 8 +++++++-
block/qcow.c | 1 +
block/qcow2.c | 1 +
block/qed.c | 1 +
block/raw-posix.c | 10 +---------
block/raw-win32.c | 7 +------
block/rbd.c | 1 +
block/sheepdog.c | 1 +
block/vdi.c | 1 +
block/vmdk.c | 1 +
include/block/block.h | 1 +
11 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/block.c b/block.c
index 8e77d46..7b36fb9 100644
--- a/block.c
+++ b/block.c
@@ -2916,6 +2916,11 @@ void bdrv_flush_all(void)
}
}
+int bdrv_has_zero_init_1(BlockDriverState *bs)
+{
+ return 1;
+}
+
int bdrv_has_zero_init(BlockDriverState *bs)
{
assert(bs->drv);
@@ -2924,7 +2929,8 @@ int bdrv_has_zero_init(BlockDriverState *bs)
return bs->drv->bdrv_has_zero_init(bs);
}
- return 1;
+ /* save default */
+ return 0;
}
typedef struct BdrvCoIsAllocatedData {
diff --git a/block/qcow.c b/block/qcow.c
index e2a64c7..5239bd6 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -892,6 +892,7 @@ static BlockDriver bdrv_qcow = {
.bdrv_close = qcow_close,
.bdrv_reopen_prepare = qcow_reopen_prepare,
.bdrv_create = qcow_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_readv = qcow_co_readv,
.bdrv_co_writev = qcow_co_writev,
diff --git a/block/qcow2.c b/block/qcow2.c
index 9383990..0eceefe 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1785,6 +1785,7 @@ static BlockDriver bdrv_qcow2 = {
.bdrv_close = qcow2_close,
.bdrv_reopen_prepare = qcow2_reopen_prepare,
.bdrv_create = qcow2_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_is_allocated = qcow2_co_is_allocated,
.bdrv_set_key = qcow2_set_key,
.bdrv_make_empty = qcow2_make_empty,
diff --git a/block/qed.c b/block/qed.c
index 4651403..f767b05 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1574,6 +1574,7 @@ static BlockDriver bdrv_qed = {
.bdrv_close = bdrv_qed_close,
.bdrv_reopen_prepare = bdrv_qed_reopen_prepare,
.bdrv_create = bdrv_qed_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_is_allocated = bdrv_qed_co_is_allocated,
.bdrv_make_empty = bdrv_qed_make_empty,
.bdrv_aio_readv = bdrv_qed_aio_readv,
diff --git a/block/raw-posix.c b/block/raw-posix.c
index c0ccf27..8597d77 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1199,6 +1199,7 @@ static BlockDriver bdrv_file = {
.bdrv_reopen_abort = raw_reopen_abort,
.bdrv_close = raw_close,
.bdrv_create = raw_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_is_allocated = raw_co_is_allocated,
.bdrv_aio_readv = raw_aio_readv,
@@ -1526,11 +1527,6 @@ static int hdev_create(const char *filename,
QEMUOptionParameter *options)
return ret;
}
-static int hdev_has_zero_init(BlockDriverState *bs)
-{
- return 0;
-}
-
static BlockDriver bdrv_host_device = {
.format_name = "host_device",
.protocol_name = "host_device",
@@ -1543,7 +1539,6 @@ static BlockDriver bdrv_host_device = {
.bdrv_reopen_abort = raw_reopen_abort,
.bdrv_create = hdev_create,
.create_options = raw_create_options,
- .bdrv_has_zero_init = hdev_has_zero_init,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
@@ -1668,7 +1663,6 @@ static BlockDriver bdrv_host_floppy = {
.bdrv_reopen_abort = raw_reopen_abort,
.bdrv_create = hdev_create,
.create_options = raw_create_options,
- .bdrv_has_zero_init = hdev_has_zero_init,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
@@ -1770,7 +1764,6 @@ static BlockDriver bdrv_host_cdrom = {
.bdrv_reopen_abort = raw_reopen_abort,
.bdrv_create = hdev_create,
.create_options = raw_create_options,
- .bdrv_has_zero_init = hdev_has_zero_init,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
@@ -1892,7 +1885,6 @@ static BlockDriver bdrv_host_cdrom = {
.bdrv_reopen_abort = raw_reopen_abort,
.bdrv_create = hdev_create,
.create_options = raw_create_options,
- .bdrv_has_zero_init = hdev_has_zero_init,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
diff --git a/block/raw-win32.c b/block/raw-win32.c
index 7c03b6d..9b5b2af 100644
--- a/block/raw-win32.c
+++ b/block/raw-win32.c
@@ -459,6 +459,7 @@ static BlockDriver bdrv_file = {
.bdrv_file_open = raw_open,
.bdrv_close = raw_close,
.bdrv_create = raw_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
@@ -570,11 +571,6 @@ static int hdev_open(BlockDriverState *bs, QDict *options,
int flags)
return 0;
}
-static int hdev_has_zero_init(BlockDriverState *bs)
-{
- return 0;
-}
-
static BlockDriver bdrv_host_device = {
.format_name = "host_device",
.protocol_name = "host_device",
@@ -582,7 +578,6 @@ static BlockDriver bdrv_host_device = {
.bdrv_probe_device = hdev_probe_device,
.bdrv_file_open = hdev_open,
.bdrv_close = raw_close,
- .bdrv_has_zero_init = hdev_has_zero_init,
.bdrv_aio_readv = raw_aio_readv,
.bdrv_aio_writev = raw_aio_writev,
diff --git a/block/rbd.c b/block/rbd.c
index 0f2608b..cb71751 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -996,6 +996,7 @@ static BlockDriver bdrv_rbd = {
.bdrv_file_open = qemu_rbd_open,
.bdrv_close = qemu_rbd_close,
.bdrv_create = qemu_rbd_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_get_info = qemu_rbd_getinfo,
.create_options = qemu_rbd_create_options,
.bdrv_getlength = qemu_rbd_getlength,
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 1b7c3f1..b397b5b 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2401,6 +2401,7 @@ static BlockDriver bdrv_sheepdog_unix = {
.bdrv_file_open = sd_open,
.bdrv_close = sd_close,
.bdrv_create = sd_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_getlength = sd_getlength,
.bdrv_truncate = sd_truncate,
diff --git a/block/vdi.c b/block/vdi.c
index 2662d89..8a91525 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -779,6 +779,7 @@ static BlockDriver bdrv_vdi = {
.bdrv_close = vdi_close,
.bdrv_reopen_prepare = vdi_reopen_prepare,
.bdrv_create = vdi_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_is_allocated = vdi_co_is_allocated,
.bdrv_make_empty = vdi_make_empty,
diff --git a/block/vmdk.c b/block/vmdk.c
index 975e1d4..c45e2e2 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1814,6 +1814,7 @@ static BlockDriver bdrv_vmdk = {
.bdrv_co_write_zeroes = vmdk_co_write_zeroes,
.bdrv_close = vmdk_close,
.bdrv_create = vmdk_create,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
.bdrv_co_flush_to_disk = vmdk_co_flush,
.bdrv_co_is_allocated = vmdk_co_is_allocated,
.bdrv_get_allocated_file_size = vmdk_get_allocated_file_size,
diff --git a/include/block/block.h b/include/block/block.h
index 2307f67..dd8eca1 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -272,6 +272,7 @@ void bdrv_drain_all(void);
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);
int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
int *pnum);
--
1.7.9.5
