block/file-win32.c | 100 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 99 insertions(+), 1 deletion(-)
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 <hreitz@redhat.com>
Signed-off-by: Viktor Prutyanov <viktor.prutyanov@phystech.edu>
Tested-by: Helge Konetzka <hk@zapateado.de>
---
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
@@ -58,6 +58,10 @@ typedef struct BDRVRawState {
QEMUWin32AIOState *aio;
} BDRVRawState;
+typedef struct BDRVRawReopenState {
+ HANDLE hfile;
+} BDRVRawReopenState;
+
/*
* Read/writes the data to/from a given linear buffer.
*
@@ -392,7 +396,7 @@ static int raw_open(BlockDriverState *bs, QDict *options, int flags,
}
s->hfile = CreateFile(filename, access_flags,
- FILE_SHARE_READ, NULL,
+ FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
OPEN_EXISTING, overlapped, NULL);
if (s->hfile == INVALID_HANDLE_VALUE) {
int err = GetLastError();
@@ -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;
+ }
+ }
+
+ state->opaque = rs;
+
+ return 0;
+
+fail:
+ g_free(rs);
+ state->opaque = NULL;
+
+ return ret;
+}
+
+static void raw_reopen_commit(BDRVReopenState *state)
+{
+ BDRVRawState *s = state->bs->opaque;
+ BDRVRawReopenState *rs = state->opaque;
+
+ assert(rs != NULL);
+
+ CloseHandle(s->hfile);
+ s->hfile = rs->hfile;
+
+ g_free(rs);
+ state->opaque = NULL;
+}
+
+static void raw_reopen_abort(BDRVReopenState *state)
+{
+ BDRVRawReopenState *rs = state->opaque;
+
+ if (!rs) {
+ return;
+ }
+
+ if (rs->hfile != INVALID_HANDLE_VALUE) {
+ CloseHandle(rs->hfile);
+ }
+
+ g_free(rs);
+ state->opaque = NULL;
+}
+
static QemuOptsList raw_create_opts = {
.name = "raw-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
@@ -659,6 +753,10 @@ BlockDriver bdrv_file = {
.bdrv_co_create_opts = raw_co_create_opts,
.bdrv_has_zero_init = bdrv_has_zero_init_1,
+ .bdrv_reopen_prepare = raw_reopen_prepare,
+ .bdrv_reopen_commit = raw_reopen_commit,
+ .bdrv_reopen_abort = raw_reopen_abort,
+
.bdrv_aio_preadv = raw_aio_preadv,
.bdrv_aio_pwritev = raw_aio_pwritev,
.bdrv_aio_flush = raw_aio_flush,
--
2.21.0
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 <hreitz@redhat.com> > Signed-off-by: Viktor Prutyanov <viktor.prutyanov@phystech.edu> > Tested-by: Helge Konetzka <hk@zapateado.de> > --- > 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; > +}
© 2016 - 2024 Red Hat, Inc.