On 25.08.21 01:48, Viktor Prutyanov wrote:
Make 'qemu-img commit' work on Windows.
Command 'commit' requires reopening backing file in RW mode. So,
add reopen prepare/commit/abort handlers and change dwShareMode
for CreateFile call in order to allow further read/write reopening.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/418
Suggested-by: Hanna Reitz <[email protected]>
Signed-off-by: Viktor Prutyanov <[email protected]>
Tested-by: Helge Konetzka <[email protected]>
---
v2:
- fix indentation in raw_reopen_prepare
- free rs if raw_reopen_prepare fails
v3:
- restore suggested-by field missed in v2
v4:
- add file type check
- add comment about options
- replace rs check with assert in raw_reopen_commit
block/file-win32.c | 100 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 99 insertions(+), 1 deletion(-)
diff --git a/block/file-win32.c b/block/file-win32.c
index 2642088bd6..8320495f2b 100644
--- a/block/file-win32.c
+++ b/block/file-win32.c
[...]
@@ -634,6 +638,96 @@ static int coroutine_fn raw_co_create_opts(BlockDriver
*drv,
return raw_co_create(&options, errp);
}
+static int raw_reopen_prepare(BDRVReopenState *state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ BDRVRawState *s = state->bs->opaque;
+ BDRVRawReopenState *rs;
+ int access_flags;
+ DWORD overlapped;
+ int ret = 0;
+
+ if (s->type != FTYPE_FILE) {
+ error_setg(errp, "Can only reopen files");
+ return -EINVAL;
+ }
+
+ rs = g_new0(BDRVRawReopenState, 1);
+
+ /*
+ * We do not support changing any options (only flags). By leaving
+ * all options in state->options, we tell the generic reopen code
+ * that we do not support changing any of them, so it will verify
+ * that their values did not change.
+ */
+
+ raw_parse_flags(state->flags, s->aio != NULL, &access_flags, &overlapped);
+ rs->hfile = CreateFile(state->bs->filename, access_flags,
+ FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
+ OPEN_EXISTING, overlapped, NULL);
+
+ if (rs->hfile == INVALID_HANDLE_VALUE) {
+ int err = GetLastError();
+
+ error_setg_win32(errp, err, "Could not reopen '%s'",
+ state->bs->filename);
+ if (err == ERROR_ACCESS_DENIED) {
+ ret = -EACCES;
+ } else {
+ ret = -EINVAL;
+ }
+ goto fail;
+ }
+
+ if (s->aio) {
+ ret = win32_aio_attach(s->aio, rs->hfile);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not enable AIO");
+ goto fail;
I believe if we fail here, we’ve already opened rs->hfile, so we must
close it or we’d leak it.
(Sorry I missed this in my v3 review :/)
Hanna
+ }
+ }
+
+ state->opaque = rs;
+
+ return 0;
+
+fail:
+ g_free(rs);
+ state->opaque = NULL;
+
+ return ret;
+}
