From: Liu Yuan <tailai...@taobao.com>
The 'qemu-img convert -h' advertise that the default cache mode is
'writeback', while in fact it is 'unsafe'.
This patch 1) fix the help manual and 2) let bdrv_close() call bdrv_flush()
3) explicitly calls bdrv_close() to flush the dirty bits.
3) is needed because some backend storage doesn't have a self-flush
mechanism(for e.g., sheepdog), so we need to call bdrv_close() to make
sure the image is really writen to the storage instead of hanging around
writeback cache forever.
Signed-off-by: Liu Yuan <tailai...@taobao.com>
---
block.c | 1 +
qemu-img.c | 7 +++++--
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/block.c b/block.c
index c0c90f0..1ee2bf0 100644
--- a/block.c
+++ b/block.c
@@ -812,6 +812,7 @@ unlink_and_fail:
void bdrv_close(BlockDriverState *bs)
{
+ bdrv_flush(bs);
if (bs->drv) {
if (bs->job) {
block_job_cancel_sync(bs->job);
diff --git a/qemu-img.c b/qemu-img.c
index 6a61ca8..846f707 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -66,8 +66,8 @@ static void help(void)
" 'filename' is a disk image filename\n"
" 'fmt' is the disk image format. It is guessed automatically in
most cases\n"
" 'cache' is the cache mode used to write the output disk image,
the valid\n"
- " options are: 'none', 'writeback' (default), 'writethrough',
'directsync'\n"
- " and 'unsafe'\n"
+ " options are: 'none', 'writeback', 'writethrough',
'directsync'\n"
+ " and 'unsafe' (default)\n"
" 'size' is the disk image size in bytes. Optional suffixes\n"
" 'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G'
(gigabyte, 1024M)\n"
" and T (terabyte, 1024G) are supported. 'b' is ignored.\n"
@@ -1036,6 +1036,9 @@ out:
free_option_parameters(param);
qemu_vfree(buf);
if (out_bs) {
+ if (ret == 0) {
+ bdrv_close(out_bs);
+ }
bdrv_delete(out_bs);
}
if (bs) {
--
1.7.8.2
