From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Andryuk Subject: [PATCH] libxl: Reset toolstack_save file position in libxl Date: Sat, 17 May 2014 11:35:38 -0400 Message-ID: <1400340938-18101-1-git-send-email-andryuk@aero.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: Jason Andryuk , Ian Jackson , Ian Campbell , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org toolstack_save data is written to a temporary file in libxl and read back in libxl-save-helper. The file position must be reset prior to reading the file, which is done in libxl-save-helper with lseek. lseek is unsupported for pipes and sockets, so a wrapper passing such an fd to libxl-save-helper fails the lseek. Moving the lseek to libxl avoids the error, allowing the save to continue. Signed-off-by: Jason Andryuk --- tools/libxl/libxl_save_callout.c | 6 ++++++ tools/libxl/libxl_save_helper.c | 5 ++--- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/tools/libxl/libxl_save_callout.c b/tools/libxl/libxl_save_callout.c index e3bda8f..d907e2d 100644 --- a/tools/libxl/libxl_save_callout.c +++ b/tools/libxl/libxl_save_callout.c @@ -105,6 +105,12 @@ void libxl__xc_domain_save(libxl__egc *egc, libxl__domain_suspend_state *dss, toolstack_data_buf, toolstack_data_len, "toolstack data tmpfile", 0); if (r) { rc = ERROR_FAIL; goto out; } + + /* + * file position must be reset before passing to libxl-save-helper. + */ + r = lseek(toolstack_data_fd, 0, SEEK_SET); + if (r) { rc = ERROR_FAIL; goto out; } } const unsigned long argnums[] = { diff --git a/tools/libxl/libxl_save_helper.c b/tools/libxl/libxl_save_helper.c index c36314c..b259bd0 100644 --- a/tools/libxl/libxl_save_helper.c +++ b/tools/libxl/libxl_save_helper.c @@ -163,10 +163,9 @@ static uint32_t toolstack_save_len; static int toolstack_save_cb(uint32_t domid, uint8_t **buf, uint32_t *len, void *data) { - assert(toolstack_save_fd > 0); + int r; - int r = lseek(toolstack_save_fd, 0, SEEK_SET); - if (r) fail(errno,"rewind toolstack data tmpfile"); + assert(toolstack_save_fd > 0); *buf = xmalloc(toolstack_save_len); r = read_exactly(toolstack_save_fd, *buf, toolstack_save_len); -- 1.8.3.1