On Tue, Aug 27, 2013 at 10:34:54AM -0700, Ian Main wrote:
On Tue, Aug 27, 2013 at 03:28:07PM +0100, Daniel P. Berrange wrote:
On Mon, Aug 26, 2013 at 12:30:39PM -0700, Ian Main wrote:
This patch changes virFileLoopDeviceOpen() to use the new loop-control device to allocate a new loop device. If this behavior is unsupported or an error occurs while trying to do this it falls back to the previous method of searching /dev for a free device.
With this patch you can start as many image based LXC domains as you like (well almost).
Fixes bug https://bugzilla.redhat.com/show_bug.cgi?id=995543
Signed-off-by: Ian Main <imain@redhat.com> --- configure.ac | 12 +++++++++++ src/util/virfile.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 72 insertions(+), 1 deletion(-)
#if defined(__linux__) && HAVE_DECL_LO_FLAGS_AUTOCLEAR -static int virFileLoopDeviceOpen(char **dev_name) + +#if HAVE_DECL_LOOP_CTL_GET_FREE +static int virFileLoopDeviceOpenLoopCtl(char **dev_name) +{ + int fd = -1; + int devnr; + char *looppath = NULL; + + VIR_DEBUG("Opening loop-control device"); + if ((fd = open("/dev/loop-control", O_RDWR)) < 0) { + virReportSystemError(errno, "%s", + _("Unable to open /dev/loop-control")); + return -1;
We need to distinguish ENOENT (which should be non-fatal) from other (fatal) errors here.
I'd suggest that we add an 'int *fd' parameter to this method, and use the return value to indicate success / failure only.
eg,
if (virFileLoopDeviceOpenLoopCtl(devname, &fd) < 0) return -1; if (fd == -1) fd = virFileLoopDeviceOpenSearch(devname); return fd;
You bet. To be clear does this mean you don't want to fall back to the search method in the case of an error while using loop-control allocation? My thinking was we'd just give it a go regardless of the issue..
nm, I see. heh Ian