file-posix: Factor out raw_reconfigure_getfd() (5cec2870) · Commits · SUMMER2020 / students / proj-2021291

block/file-posix.c

+62 −45

Original line number	Diff line number	Diff line
		@@ -842,6 +842,62 @@ static int raw_handle_perm_lock(BlockDriverState *bs,
		return ret;
		}

		static int raw_reconfigure_getfd(BlockDriverState *bs, int flags,
		int open_flags, Error *errp)
		{
		BDRVRawState *s = bs->opaque;
		int fd = -1;
		int ret;
		int fcntl_flags = O_APPEND \| O_NONBLOCK;
		#ifdef O_NOATIME
		fcntl_flags \|= O_NOATIME;
		#endif

		*open_flags = 0;
		if (s->type == FTYPE_CD) {
		*open_flags \|= O_NONBLOCK;
		}

		raw_parse_flags(flags, open_flags);

		#ifdef O_ASYNC
		/* Not all operating systems have O_ASYNC, and those that don't
		* will not let us track the state into rs->open_flags (typically
		* you achieve the same effect with an ioctl, for example I_SETSIG
		* on Solaris). But we do not use O_ASYNC, so that's fine.
		*/
		assert((s->open_flags & O_ASYNC) == 0);
		#endif

		if ((*open_flags & ~fcntl_flags) == (s->open_flags & ~fcntl_flags)) {
		/* dup the original fd */
		fd = qemu_dup(s->fd);
		if (fd >= 0) {
		ret = fcntl_setfl(fd, *open_flags);
		if (ret) {
		qemu_close(fd);
		fd = -1;
		}
		}
		}

		/* If we cannot use fcntl, or fcntl failed, fall back to qemu_open() */
		if (fd == -1) {
		const char *normalized_filename = bs->filename;
		ret = raw_normalize_devicepath(&normalized_filename, errp);
		if (ret >= 0) {
		assert(!(*open_flags & O_CREAT));
		fd = qemu_open(normalized_filename, *open_flags);
		if (fd == -1) {
		error_setg_errno(errp, errno, "Could not reopen file");
		return -1;
		}
		}
		}

		return fd;
		}

		static int raw_reopen_prepare(BDRVReopenState *state,
		BlockReopenQueue queue, Error *errp)
		{
		@@ -858,7 +914,6 @@ static int raw_reopen_prepare(BDRVReopenState *state,

		state->opaque = g_new0(BDRVRawReopenState, 1);
		rs = state->opaque;
		rs->fd = -1;

		/* Handle options changes */
		opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
		@@ -877,50 +932,12 @@ static int raw_reopen_prepare(BDRVReopenState *state,
		* bdrv_reopen_prepare() will detect changes and complain. */
		qemu_opts_to_qdict(opts, state->options);

		if (s->type == FTYPE_CD) {
		rs->open_flags \|= O_NONBLOCK;
		}

		raw_parse_flags(state->flags, &rs->open_flags);

		int fcntl_flags = O_APPEND \| O_NONBLOCK;
		#ifdef O_NOATIME
		fcntl_flags \|= O_NOATIME;
		#endif

		#ifdef O_ASYNC
		/* Not all operating systems have O_ASYNC, and those that don't
		* will not let us track the state into rs->open_flags (typically
		* you achieve the same effect with an ioctl, for example I_SETSIG
		* on Solaris). But we do not use O_ASYNC, so that's fine.
		*/
		assert((s->open_flags & O_ASYNC) == 0);
		#endif

		if ((rs->open_flags & ~fcntl_flags) == (s->open_flags & ~fcntl_flags)) {
		/* dup the original fd */
		rs->fd = qemu_dup(s->fd);
		if (rs->fd >= 0) {
		ret = fcntl_setfl(rs->fd, rs->open_flags);
		if (ret) {
		qemu_close(rs->fd);
		rs->fd = -1;
		}
		}
		}

		/* If we cannot use fcntl, or fcntl failed, fall back to qemu_open() */
		if (rs->fd == -1) {
		const char *normalized_filename = state->bs->filename;
		ret = raw_normalize_devicepath(&normalized_filename, errp);
		if (ret >= 0) {
		assert(!(rs->open_flags & O_CREAT));
		rs->fd = qemu_open(normalized_filename, rs->open_flags);
		if (rs->fd == -1) {
		error_setg_errno(errp, errno, "Could not reopen file");
		rs->fd = raw_reconfigure_getfd(state->bs, state->flags, &rs->open_flags,
		&local_err);
		if (local_err) {
		error_propagate(errp, local_err);
		ret = -1;
		}
		}
		goto out;
		}

		/* Fail already reopen_prepare() if we can't get a working O_DIRECT